Internists
40 years of experience

Airport Heights
2925 Debarr Rd
Anchorage, AK 99508
907-257-7412
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Education ?

Medical School Score Rankings
University of Minnesota, Twin Cities (1970)
  • Currently 4 of 4 apples
Top 25%

Awards & Distinctions ?

Associations
American Board of Internal Medicine

Publications & Research

Dr. Regan has contributed to 66 publications.
Title Lower Incidence of Dysphagia with Cervical Arthroplasty Compared with Acdf in a Prospective Randomized Clinical Trial.
Date June 2010
Journal Journal of Spinal Disorders & Techniques
Excerpt

The current study of 251 consecutive 1-level anterior cervical reconstructions was undertaken to compare the incidence of dysphagia between cervical disk replacement and conventional anterior cervical fusion and instrumentation.

Title Cervical Disc Replacement in Patients with and Without Previous Adjacent Level Fusion Surgery: a Prospective Study.
Date May 2009
Journal Spine
Excerpt

Prospective 6-center study. OBJECTIVE.: To evaluate outcomes of cervical disc replacement performed adjacent to a prior cervical fusion.

Title Effect of Previous Surgery on Clinical Outcome Following 1-level Lumbar Arthroplasty.
Date March 2008
Journal Journal of Neurosurgery. Spine
Excerpt

OBJECT: A secondary lumbar surgery at a previously surgically treated level is believed to result in minimal clinical improvement. The clinical results of the CHARITE Investigational Device Exemption (IDE) study were analyzed to assess the effect of previous surgery on clinical outcomes following either total disc replacement with the CHARITE device or anterior lumbar interbody fusion with a BAK cage and iliac crest autograft. METHODS: Patients with prior microdiscectomy, laminectomy, or minimal medial facetectomy were not excluded from enrollment in the CHARITE IDE study. Thus, the following 3 groups were analyzed: all patients treated with the CHARITE Artificial Disc, whether randomized or nonrandomized; only patients treated with CHARITE devices randomized against patients with BAK devices; and control patients with BAK devices. Each group was further subdivided based on the patients' medical history, whether they had undergone prior surgery (prior surgery group) or had not (no prior surgery group). For all groups, baseline demographics were collected and compared for any potential recruitment bias. Postoperative improvements based on Oswestry Disability Index (ODI), visual analog scale (VAS), and patient satisfaction scores were further collected and statistically analyzed. RESULTS: For all 3 groups, there were no statistical differences in clinical improvement from 3 months to 2 years postoperatively as measured using ODI and VAS scores between the subgroups (those who had prior surgery and those who did not). CONCLUSIONS: Patients indicated for 1-level lumbar arthroplasty with previous lumbar decompressive surgery can be expected to have similar clinical outcomes to patients undergoing arthroplasty without prior lumbar decompressive surgery. Similarly, candidates for anterior lumbar fusion with prior decompressive surgery may experience similar benefits from the surgical procedure as those without.

Title Distribution of in Vivo and in Vitro Range of Motion Following 1-level Arthroplasty with the Charite Artificial Disc Compared with Fusion.
Date February 2008
Journal Journal of Neurosurgery. Spine
Excerpt

OBJECT: One of the goals of lumbar arthroplasty is to restore and maintain range of motion (ROM) and to protect adjacent levels from abnormal motion, which may be a factor in transition syndrome following arthrodesis. In this study, in vitro ROM results were compared with in vivo, 2-year postoperative radiographic ROM evaluations. METHODS: Radiographs of patients enrolled in the CHARITE investigational device exemption study were analyzed at baseline and at 2 years postoperatively. The ROM in flexion/extension at the implanted and adjacent levels was measured, normalized, and compared with ROM results obtained using cadaver (in vitro) evaluations. RESULTS: Preoperative ROM distributions in patients enrolled for arthroplasty or fusion at the L4-5 level was as follows: 28% motion was observed at L3-4, 35% at L4-5 and 37% at L5-S1. Following a one-level arthroplasty at L4-5, the in vivo ROM distribution from L-3 to S-1 at the 2-year time point was 36% at L3-4, 30% at L4-5 and 35% at L5-S1. Following a one-level fusion with BAK and pedicle screws at L4-5, the in vivo ROM distribution from L-3 to S-1 at the 2-year time point was 45% at L3-4, 9% at L4-5 and 46% at L5-S1. CONCLUSIONS: The baseline as well as the 2-year in vivo data confirmed previously published in vitro data. One-level arthroplasty was shown herein to replicate the normal distribution of motion of the intact spine.

Title Patient Selection for Lumbar Arthroplasty and Arthrodesis: the Effect of Revision Surgery in a Controlled, Multicenter, Randomized Study.
Date February 2008
Journal Journal of Neurosurgery. Spine
Excerpt

OBJECT: Patient selection is perhaps the most important factor in successful lumbar surgery. In this study, the authors analyzed the clinical outcomes of patients enrolled in the CHARITE investigational device exemption (IDE) trial who underwent revision surgery after primary total disc replacement with CHARITE or an anterior lumbar interbody fusion (ALIF) with placement of a BAK cage and iliac crest autograft. This revision surgery was either a supplemental posterior lumbar fixation or a 360 degrees fusion. Statistical analysis was conducted to compare clinical success in patients who underwent revision surgery with those who did not. METHODS: The patients enrolled in the CHARITE IDE study were divided into 6 groups according to treatment and repeated operation status, and their Oswestry Disability Index (ODI) and visual analog scale (VAS) scores at the 2-year follow-up and at baseline were compared. The patients had received the following treatments by group: A) ALIF without reoperation; B) ALIF with conversion to 360 degrees fusion; C) arthroplasty (randomized) without repeated operation; D) arthroplasty with supplemental posterior lumbar fixation; E) arthroplasty (nonrandomized) without repeated operation; and F) arthroplasty (nonrandomized) with supplemental posterior lumbar fixation. Outcome scores in the groups of patients who required revision surgeries (Groups B, D, and F; 23 patients) were compared with the groups that did not require revision surgery (Groups A, C, and E; 299 patients). RESULTS: Patients who required revision surgery had a significantly lower level of clinical improvement than those who did not. The mean change in ODI score was -53.0% in Groups A, C, and E, but just -12.7% in Groups B, D, and F (p < 0.0001). The mean change in VAS score was -59.1% in Groups A, C, and E, compared to -23.4% in Groups B, D, and F (p < 0.0001). No significant differences were identified in analyzing absolute change in scores and the percentage change. A comparison of outcomes in patients who had undergone arthroplasty without reoperation (Groups C and E) with all patients who had undergone revision surgery (Groups B, D, and F) demonstrated similar results (p < 0.0001). CONCLUSIONS: The 7.1% of patients who underwent a secondary stabilization procedure had poor clinical improvement. This finding may indicate that if the alternative treatment had been the initial treatment, these patients would not have benefited, and further implies a 7.1% rate of imprecision in preoperative evaluation.

Title An Economic Model of One-level Lumbar Arthroplasty Versus Fusion.
Date January 2008
Journal The Spine Journal : Official Journal of the North American Spine Society
Excerpt

BACKGROUND CONTEXT: Degenerative disc disease (DDD) is a cause of low back pain commonly requiring surgical intervention. The option of lumbar total disc replacement (TDR) represents an advance in the surgical treatment of DDD. However, new treatments, particularly those that include the use of new implants, may lead to increased costs to both hospitals and payers. Therefore, it is both necessary and appropriate to examine the potential costs associated with a new procedure such as total disc replacement compared with traditional treatments for a specific pathology. PURPOSE: To perform an economic analysis of lumbar TDR versus three different techniques for lumbar fusion. STUDY DESIGN/SETTING: A cost-minimization model. METHODS: An economic model examining hospital and payer cost perspectives was developed to compare costs of TDR with the CHARITE Artificial Disc to three spinal fusion procedures: anterior lumbar interbody fusion (ALIF) with iliac crest bone graft (ICBG); ALIF with INFUSE Bone Graft and LT-Cages, and instrumented posterior lumbar interbody fusion (IPLIF) with ICBG. The hospital perspective compares direct medical costs during the index hospitalization. The payer perspective considers direct medical costs of the index hospitalization and those incurred in the following two-year period. The model contains a Diagnostic Related Group (DRG) arm based strictly on DRG coding and payment, and a per-diem arm that includes a device carve-out cost and payment. RESULTS: In the DRG and per-diem arms of the model, compared with TDR, hospital costs are 12.0% higher for ALIF with ICBG, 36.5% higher for ALIF with INFUSE, and 36.5% higher for IPLIF. For payers, in the per-diem arm compared with TDR, ALIF with ICBG has 4.4% lower cost, whereas ALIF with INFUSE and IPLIF have costs of 16.1% and 27.1% higher, respectively. In the DRG arm compared with TDR, payer cost is 87.1% higher for ALIF with ICBG, 82.8% higher for ALIF with INFUSE, and 99.0% higher for IPLIF. CONCLUSIONS: The model shows that the overall economic effect of one-level TDR procedures on hospitals and payers is likely to be less than or at worse equivalent to one-level lumbar fusion procedures.

Title Revision and Explantation Strategies Involving the Charite Lumbar Artificial Disc Replacement.
Date May 2007
Journal Spine
Excerpt

STUDY DESIGN: A large case series of anterior revision surgery in patients who had complications following lumbar total disc replacement with the CHARITE artificial disc. OBJECTIVES: To analyze and discuss the etiology of implant-related complications and to present a strategy that can be applied to lumbar intervertebral disc prostheses in cases where anterior revision surgery is necessary. SUMMARY OF BACKGROUND DATA: This report represents the largest single-site, consecutive case series reported in the literature of anterior revision surgery following lumbar disc arthroplasty. METHODS: A total of 18 patients are included in this study. All patients required an anterior revision procedure for repositioning or removal of the prosthesis. The mean time to revision was 6 months (range, 9 days to 4 years). RESULTS: In 17 of 20 cases, implant removal was required and the patient was converted to a fusion. In 3 cases, primary revision of the CHARITE artificial disc was performed. Six revision cases were performed within the early postoperative period, defined as 7 to 14 days. All early cases were approached via reexploration of the original anterior midline retroperitoneal incision. Late revision was required in 14 cases, ranging from 3 weeks to 4 years following initial arthroplasty. A variety of surgical approaches were used in late revisions, including the lateral transpsoas approach at L3-L4 or L4-L5 (n = 5), expanded ipsilateral left retroperitoneal approach at L4-L5 (n = 2), contralateral right retroperitoneal approach at L5-S1 (n = 6), and transperitoneal approach (n = 1). Following 20 consecutive, anterior revision procedures, implant revision was successfully achieved in all cases. CONCLUSIONS: Total disc replacement implant revisions occur largely as a result of technical errors in positioning and sizing of the implant. In addition, adherence to strict patient selection criteria will eliminate many cases of implant failure. When necessary, anterior revision surgery can be performed safely when a strategic approach is used.

Title Access Strategies for Revision or Explantation of the Charité Lumbar Artificial Disc Replacement.
Date January 2007
Journal Journal of Vascular Surgery : Official Publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
Excerpt

BACKGROUND: Several lumbar disc prostheses are being developed with the goal of preserving mobility in patients with degenerative disc disease. The disadvantage of lumbar artificial disc replacement (ADR) compared with anterior interbody fusion (ALIF) is the increased potential for displacement or component failure. Revision or removal of the device is complicated by adherence of the aorta, iliac vessels, and the ureter to the operative site. Because of these risks of anterior lumbar procedures, vascular surgeons usually provide access to the spine. We report our experience with secondary exposure of the lumbar spine for revision or explantation of the Charité disc prosthesis. METHODS: Between January 2001 and May 2006, 19 patients with prior implantation of Charité Artificial Discs required 21 operations for repositioning or removal of the device. Two patients had staged removal of prostheses at two levels. One patient had simultaneous explantation at two levels. The mean age was 49 years (range, 31 to 69 years; 56% men, 42% women). The initial ADR was performed at our institution in 14 patients (74%). The mean time from implantation to reoperation was 7 months (range, 9 days to 4 years). The levels of failure were L3-4 in one, L4-5 in nine, and L5-S1 in 12. RESULTS: The ADR was successfully removed or revised in all patients that underwent reoperation. Three of the 12 procedures at L5-S1 were performed through the same retroperitoneal approach as the initial access. One of these three, performed after a 3-week interval, was converted to a transperitoneal approach because of adhesions. The rest of the L5-S1 prostheses were exposed from a contralateral retroperitoneal approach. Four of the L4-5 prostheses were accessed from the original approach and five from a lateral, transpsoas exposure (four left, one right). The only explantation at L3-4 was from a left lateral transpsoas approach. Nineteen of the 22 ADR were converted to ALIF. Two revisions at L5-S1 involved replacement of the entire prosthesis. One revision at L4-5 required only repositioning of an endplate. Access-related complications included, in one patient each, iliac vein injury, temporary retrograde ejaculation, small-bowel obstruction requiring lysis, and symptomatic, large retroperitoneal lymphocele. There were no permanent neurologic deficits, deep vein thromboses, or deaths. CONCLUSIONS: Owing to vascular and ureteral fixation, anterior exposure of the lumbar spine for revision or explantation of the Charité disc replacement should be performed through an alternative approach unless the procedure is performed < or = 2 weeks of the index procedure. The L5-S1 level can be accessed through the contralateral retroperitoneum. Reoperation at L3-4 and L4-5 usually requires explantation and fusion that is best accomplished by way of a lateral transpsoas exposure.

Title Revisability of the Charite Artificial Disc Replacement: Analysis of 688 Patients Enrolled in the U.s. Ide Study of the Charite Artificial Disc.
Date September 2006
Journal Spine
Excerpt

STUDY DESIGN: A prospective, randomized, multicenter, FDA-regulated Investigational Device Exemption clinical trial. OBJECTIVES: To analyze the incidence of, and reasons for, reoperation in all patients (treatment and control) enrolled in the IDE study. SUMMARY OF BACKGROUND DATA: This is the first report of the incidence and nature of reoperations following lumbar TDR as part of a controlled, prospective, multicenter trial. METHODS: A total of 688 patients meeting the inclusion and exclusion criteria were enrolled in one of three arms of the study at 14 centers across the United States. This cohort includes 71 nonrandomized cases, 205 randomized cases, and 313 continued access cases, all receiving the CHARITE Artificial Disc, as well as 99 randomized cases in the control group (ALIF with threaded fusion cages and autograft). A detailed analysis was performed of clinical chart notes, operative notes, and adverse event reports for all patients requiring reoperation following their index surgery. RESULTS: Of the 589 patients with TDR, 52 (8.8%) required reoperation. Of the 99 patients with lumbar fusion, 10 (10.1%) required reoperation, and an additional 2 required surgery for adjacent level disease (P = 0.7401). There were 24 TDR patients who underwent a repeated anterior retroperitoneal approach, with 22 (91.7%) having had a successful removal of the prosthesis. Seven of the 24 TDR prostheses requiring removal were revised to another CHARITE Artificial Disc. The mean time to reoperation in all patients was 9.7 months. A total of 29 patients (4.9%) in the TDR group required posterior instrumentation and fusion as did 10 (10.1%) in the control group (P = 0.0562). At 2 years or more follow-up, 93.9%(553/589 = 93.9%) of patients receiving TDR with the CHARITE Artificial Disc had a successfully functioning prosthesis with a mean of over 7 degrees of flexion-extension mobility. CONCLUSIONS: Lumbar TDR with the CHARITE Artificial Disc did not preclude any further procedures at the index level during primary insertion, with nearly one third being revisable to a new motion-preserving prosthesis and just over two thirds being successfully converted to ALIF and/ or posterior pedicle screw arthrodesis, the original alternative procedure.

Title Evaluation of Surgical Volume and the Early Experience with Lumbar Total Disc Replacement As Part of the Investigational Device Exemption Study of the Charité Artificial Disc.
Date September 2006
Journal Spine
Excerpt

STUDY DESIGN: A prospective, randomized, multicenter, Food and Drug Administration regulated Investigational Device Exemption (IDE) clinical trial. OBJECTIVES: To discern whether there is a correlation between surgical volume and clinical outcomes, as well as the complication rate and perioperative data points, for lumbar total disc replacement. To examine the early experience for lumbar total disc replacement as part of an IDE study. SUMMARY OF BACKGROUND DATA: To our knowledge, an analysis of the effect of surgical volume has not been performed for any spine surgical procedure. Prior reports of the early experience with lumbar total disc replacement consist of retrospective reviews with nonspecific indications. METHODS: An analysis was performed of the Food and Drug Administration IDE Study of the Charité Artificial Disc (DePuy Spine, Inc., Raynham, MA). Patients enrolled in the control group were omitted from the analysis. Up to 5 nonrandomized cases (representing the early experience) were performed at each site before beginning the randomized arm of the study. There were 3 comparisons performed: nonrandomized cases (71) versus randomized cases (205); randomized cases performed by high-enrolling surgeons versus low-enrolling surgeons; and randomized cases at high-volume institutions versus low-volume institutions. RESULTS: The high-enrolling groups had a significantly lower mean hospital stay and operating time compared to the low-enrolling groups (P < 0.05). High-enrolling surgeons and institutions showed significantly shorter operating times, length of hospital stay, and complication rates. High-enrolling surgeons had significantly fewer device failures and cases of neurologic deterioration. Mean operating time and hospital stay were significantly lower in the randomized group (P < 0.05) compared to the nonrandomized group. Blood loss and approach-related complications were similar between the 2 groups. Device failure requiring removal was 4.2% in the nonrandomized group and 1.5% in the randomized group. CONCLUSIONS: Surgeons and institutions with a high volume of lumbar total disc replacement cases have a reduction in key perioperative and postoperative parameters that provide a clinical and/or economic benefit. Surgeons may expect longer hospital stays, higher blood loss, and a higher rate of certain complications in their early experience with total disc replacement procedures, but there was no effect on clinical outcomes.

Title The Use of Restraints in Psychiatric Settings.
Date June 2006
Journal Tennessee Medicine : Journal of the Tennessee Medical Association
Title A Prospective, Randomized, Multicenter Food and Drug Administration Investigational Device Exemptions Study of Lumbar Total Disc Replacement with the Charite Artificial Disc Versus Lumbar Fusion: Part I: Evaluation of Clinical Outcomes.
Date June 2006
Journal Spine
Excerpt

STUDY DESIGN: A prospective, randomized, multicenter, Food and Drug Administration-regulated Investigational Device Exemption clinical trial. OBJECTIVES: The purpose of this study was to compare the safety and effectiveness of lumbar total disc replacement, using the CHARITE artificial disc (DePuy Spine, Raynham, MA), with anterior lumbar interbody fusion, for the treatment of single-level degenerative disc disease from L4-S1 unresponsive to nonoperative treatment. SUMMARY OF BACKGROUND DATA: Reported results of lumbar total disc replacement have been favorable, but studies have been limited to retrospective case series and/or small sample sizes. METHODS: Three hundred four (304) patients were enrolled in the study at 14 centers across the United States and randomized in a 2:1 ratio to treatment with the CHARITE artificial disc or the control group, instrumented anterior lumbar interbody fusion. Data were collected pre- and perioperatively at 6 weeks and at 3, 6, 12, and 24 months following surgery. The key clinical outcome measures were a Visual Analog Scale assessing back pain, the Oswestry Disability Index questionnaire, and the SF-36 Health Survey. RESULTS: Patients in both groups improved significantly following surgery. Patients in the CHARITE artificial disc group recovered faster than patients in the control group. Patients in the CHARITE artificial disc group had lower levels of disability at every time interval from 6 weeks to 24 months, compared with the control group, with statistically lower pain and disability scores at all but the 24 month follow-up (P < 0.05). At the 24-month follow-up period, a significantly greater percentage of patients in the CHARITE artificial disc group expressed satisfaction with their treatment and would have the same treatment again, compared with the fusion group (P < 0.05). The hospital stay was significantly shorter in the CHARITE artificial disc group (P < 0.05). The complication rate was similar between both groups. CONCLUSIONS: This prospective, randomized, multicenter study demonstrated that quantitative clinical outcome measures following lumbar total disc replacement with the CHARITE artificial disc are at least equivalent to clinical outcomes with anterior lumbar interbody fusion. These results support earlier reports in the literature that total disc replacement with the CHARITE artificial disc is a safe and effective alternative to fusion for the surgical treatment of symptomatic disc degeneration in properly indicated patients. The CHARITE artificial disc group demonstrated statistically significant superiority in two major economic areas, a 1-day shorter hospitalization, and a lower rate of reoperations (5.4% compared with 9.1%). At 24 months, the investigational group had a significantly higher rate of satisfaction (73.7%) than the 53.1% rate of satisfaction in the control group (P = 0.0011). This prospective randomized multicenter study also demonstrated an increase in employment of 9.1% in the investigational group and 7.2% in the control group.

Title A Prospective, Randomized, Multicenter Food and Drug Administration Investigational Device Exemption Study of Lumbar Total Disc Replacement with the Charite Artificial Disc Versus Lumbar Fusion: Part Ii: Evaluation of Radiographic Outcomes and Correlation of Surgical Technique Accuracy with Clinical Outcomes.
Date June 2006
Journal Spine
Excerpt

STUDY DESIGN: A prospective, randomized, multicenter, Food and Drug Administration-regulated, investigational device exemption clinical trial. OBJECTIVES: To compare the safety and effectiveness of lumbar total disc replacement (TDR) with the CHARITE artificial disc (DePuy Spine, Raynham, MA) to anterior lumbar interbody fusion for the treatment of single-level degenerative disc disease from L4-S1 unresponsive to nonoperative treatment. In addition, to evaluate the radiographic outcomes of lumbar artificial disc replacement at either L4-L5 or L5-S1 with the CHARITE artificial disc as compared to anterior lumbar interbody fusion with cylindrical cages and iliac crest bone graft; and to determine if a correlation exists between clinical outcomes and surgical accuracy of TDR placement within the disc space. SUMMARY OF BACKGROUND DATA: Prior investigators have reported excellent radiographic results with the CHARITE artificial disc for the treatment of lumbar degenerative disc disease. These encouraging results are the product of retrospective reviews without a control. Very few studies have reported on the segmental motion of an intervertebral level implanted with an artificial disc, and no studies have reported a correlation of radiographic and clinical outcomes. METHODS: A prospective, randomized, multicenter, US Food and Drug Administration, investigational device exemption study with 24-month follow-up was performed at 14 centers throughout the United States. A total of 304 subjects were randomized in a 2:1 ratio, with 205 in the investigational group (TDR with the CHARITE artificial disc) and 99 in the control group (anterior lumbar interbody fusion with BAK cages and iliac crest bone graft). A total of 71 TDR training cases were performed (up to 5 at each site) before randomization beginning at each site. Plain radiographs were analyzed for each subject in both groups regarding range of motion (ROM) in flexion/extension, restoration of disc space height, and subsidence. Prosthesis placement in the coronal and midsagittal planes was analyzed for the 276 patients with TDR. Correlations were performed between prosthesis placement and clinical outcomes. RESULTS: Patients in the investigational group had a 13.6% mean increase, and those in the control group an 82.5% decrease in mean flexion/extension ROM at 24 months postoperatively compared to baseline. Patients in the investigational group had significantly better restoration of disc height than the control group (P < 0.05). There was significantly less subsidence in the investigational group compared to the control group (P < 0.05). The surgical technical accuracy of CHARITE artificial disc placement was divided into 3 groups: I, ideal (83%); II, suboptimal (11%); and III, poor (6%), and correlated with clinical outcomes. The flexion/extension ROM and prosthesis function improved with the surgical technical accuracy of radiographic placement (P = 0.003). CONCLUSIONS: Preoperative ROM in flexion/extension was restored and maintained in patients receiving a TDR. TDR with the CHARITE artificial disc resulted in significantly better restoration of disc space height, and significantly less subsidence than anterior interbody fusion with BAK cages. Clinical outcomes and flexion/extension ROM correlated with surgical technical accuracy of CHARITE artificial disc placement. In the majority of cases, placement of the CHARITE artificial disc was ideal.

Title Sagittal Alignment and the Bryan Cervical Artificial Disc.
Date January 2006
Journal Neurosurgical Focus
Excerpt

OBJECT: The authors evaluated cervical spine radiographs to determine sagittal alignment in patients who underwent one- or two-level arthroplasty with the Bryan cervical artificial disc prosthesis. METHODS: The curvature of the surgically treated spinal segments and the overall curvature of the cervical spine were evaluated in 13 patients who underwent 16 cervical arthroplasty device placements. Preoperative and postoperative lateral radiographs were reviewed and compared using standardized techniques for measuring spinal curvature. Patients who underwent a single-level cervical arthroplasty had a 4.7 degrees mean reduction (p < 0.05) in lordosis after cervical artificial disc replacement. The three patients who underwent two-level cervical arthroplasty had no significant changes in the sagittal alignment. CONCLUSIONS: Patients who underwent arthroplasty with a Bryan cervical artificial disc had a focal loss of lordosis (that is, kyphosis) at the treated levels after single-level procedures. Nevertheless, there was no significant change in the overall sagittal curvature of the cervical spine after single-level artificial disc replacements. The patients who underwent two-level artificial disc placement had no significant changes in lordosis at the treated levels or in the overall curvature. The likely source of this outcome appears to be the endplate milling procedures that reorient the vertebral endplates.

Title Clinical Results of Charité Lumbar Total Disc Replacement.
Date August 2005
Journal The Orthopedic Clinics of North America
Excerpt

To preserve segmental lumbar motion and to prevent adjacent segment disease, there has been a growing enthusiasm for the use of intervertebral disc prosthesis as an alternative to segmental lumbar fusion. To date, more than 100-disc prostheses have been designed, but only 10 prostheses have been approved and implanted in humans. The Charité Artificial Disc has had the longest clinical follow-up with more than 5000 implantations in over 30 countries and reported > 10-year satisfactory results.

Title Endoscopic Lateral Transpsoas Approach to the Lumbar Spine.
Date June 2005
Journal Spine
Excerpt

STUDY DESIGN: A description of a novel surgical approach to the lumbar spine and a prospective evaluation of the early surgical outcomes. OBJECTIVES: Describe the early postoperative results and the operative technique of a new, minimally invasive transpsoas approach for anterior fusion of the lumbar spine that minimizes the risk to large vessels and other critical structures. SUMMARY OF BACKGROUND DATA: Standard anterior endoscopic approaches to the lumbar spine require mobilization of the great vessels and sympathetic plexus. Vascular injury and retrograde ejaculation are complications clearly associated with this approach. A retroperitoneal, transpsoas approach to the lumbar spine may reduce these risks. METHODS: From 1996 to 2002, 21 patients (13 females, 8 males; mean age 50.0 years) underwent an endoscopic, retroperitoneal transpsoas approach for exposure of the lumbar spine. Surgical indications included discogenic pain in 14 patients, spinal instability at a level adjacent to a previous fusion in 3 patients, and progressive degenerative scoliosis in 4 patients. Data were reviewed to document the early postoperative results for this procedure. Illustrations were created to clearly describe this approach. RESULTS: Average operative time for the single level cases was 149 minutes (range 120-170 minutes); blood loss was 150 cc (range 50-650); postoperative hospital stay was 4.1 days. At long-term follow-up, visual analogue scale scores had decreased an average of 5.9. Mean follow-up was 3.1 years (range 2 months-6.0 years). Six patients (30%) experienced paresthesias in the groin/thigh region. Five of these same patients also complained of groin/thigh pain (27%). Two patients had symptoms that lasted longer than 1 month. One patient was converted to a mini-open lateral approach. There were no vascular injuries. CONCLUSIONS: Early results show the endoscopic lateral transpsoas approach to the lumbar spine to be a safe, minimally invasive method for anterior fusion of the first through the fourth lumbar vertebrae. Although there is a risk of groin/thigh numbness or pain, and these symptoms are mostly transient. This approach allows for exposure of the lumbar spine without mobilization of the great vessels or sympathetic plexus.

Title The Changing Role for Neurosurgeons and the Treatment of Spinal Deformity.
Date April 2005
Journal Journal of Neurosurgery. Spine
Excerpt

Spinal deformity has classically and historically been studied by those in the discipline of orthopedic surgery. This may be attributable to the orthopedic interventionalists' experience with osseous fixation for long-bone and other skeletal fractures. Neurosurgeons have maintained a long-standing interest in complex cervical spinal disorders, and their interest in the larger field of complex spinal deformity has been expanding. An understanding of spinal deformity disorders, biomechanics, bone biology, and metallurgy is necessary before clinical, teaching, and research activities can be undertaken within neurosurgery. The authors describe basic and advanced concepts of spinal deformity management with cases to illustrate teaching points.

Title Neurological Complications of Lumbar Artificial Disc Replacement and Comparison of Clinical Results with Those Related to Lumbar Arthrodesis in the Literature: Results of a Multicenter, Prospective, Randomized Investigational Device Exemption Study of Charité Intervertebral Disc. Invited Submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004.
Date September 2004
Journal Journal of Neurosurgery. Spine
Excerpt

OBJECT: Arthrodesis is the gold standard for surgical treatment of lumbar degenerative disc disease (DDD). Solid fusion, however, can cause stress and increased motion in the segments adjacent to the fused level. This may initiate and/or accelerate the adjacent-segment disease process. Artificial discs are designed to restore and maintain normal motion of the lumbar intervertebral segment. Restoring and maintaining normal motion of the segment reduces stresses and loads on adjacent level segments. A US Food and Drug Administration Investigational Device Exemptions multicentered study of the Charité artificial disc was completed. The control group consisted of individuals who underwent anterior lumbar interbody fusion involving BAK cages and iliac crest bone graft. This is the first report of Class I data in which a lumbar artificial disc is compared with lumbar fusion. METHODS: Of 304 individuals enrolled in the study, 205 were randomized to the Charité disc-treated group and 99 to the BAK fusion-treated (control) group. Neurological status was equivalent between the two groups at 6, 12, and 24 months postoperatively. The number of patients with major, minor, or other neurological complications was equivalent. There was a greater incidence of both major and minor complications in the BAK fusion group at 0 to 42 days postoperatively. Compared with data reported in the lumbar fusion literature, the Charité disc-treated patients had equivalent or better mean changes in visual analog scale and Oswestry Disability Index scores. CONCLUSIONS: The Charité artificial disc is safe and effective for the treatment of single-level lumbar DDD, resulting in no higher incidence of neurological complications compared with BAK-assisted fusion and leading to equivalent or better outcomes compared with those obtained in the control group and those reported in the lumbar fusion literature.

Title Medicolegal Aspects of Sex Reassignment Surgery in Tennessee.
Date April 2004
Journal Tennessee Medicine : Journal of the Tennessee Medical Association
Title Oxycontin: Maintaining Availability and Efficacy While Preventing Diversion and Abuse.
Date April 2003
Journal Tennessee Medicine : Journal of the Tennessee Medical Association
Title Health Care Providers' Duty to Warn.
Date March 2003
Journal Southern Medical Journal
Excerpt

Since the fifth century BC, physicians have sworn to uphold the Hippocratic Oath that includes the statement, "Whatever, in connection with my professional service, ... I see or hear, in the life of men, which ought not be spoken abroad, I will not divulge, as reckoning that all such should be kept secret." However, health care and provider responsibility have evolved so as to make this more difficult for physicians to uphold. We discuss growing issues surrounding health care providers' ability to maintain patient confidentiality and to perform their responsibilities, and their "duty to warn and/or protect" third parties. Particular Tennessee cases heard on appeal show a change in the health care enviromnent relative to provider liability to third parties.

Title Medical Malpractice and Respondeat Superior.
Date June 2002
Journal Southern Medical Journal
Excerpt

The legal concept of vicarious liability and the Doctrine of Respondeat Superior occurs when the servant (employee) commits a tort or civil wrong within the scope of employment and the master (employer) is held liable although the master may have done nothing wrong. In this article, legal cases are presented to emphasize the importance of these issues, which frequently involve physician extenders and physicians as employers in our current health care climate. Physicians need to be aware of this doctrine in the supervision of their staff and their day-to-day medical practice.

Title Video-assisted Thoracoscopic Surgery for Thoracic Disc Disease: Classification and Outcome Study of 100 Consecutive Cases with a 2-year Minimum Follow-up Period.
Date May 2002
Journal Spine
Excerpt

STUDY DESIGN: Prospectively collected data from regular clinical follow-up evaluations were tabulated, analyzed, reviewed using a patient self-reported questionnaire. OBJECTIVE: To develop a classification system and present the long-term functional outcome of video-assisted thorascopic surgery for refractory thoracic disc disease. SUMMARY OF BACKGROUND DATA: Recent studies have found an 11.1% to 14.5% prevalence of thoracic disc herniations. Surgical approaches have included laminectomy, pediculectomy, costotransversectomy, lateral extracavitary, transverse arthropediculectomy, transthoracic-transpleural thoracotomy, and thoracoscopy. Recent reports have documented encouraging early results with video-assisted thorascopic surgery for thoracic disc herniations. Comparisons between thoracoscopy and open thoracotomy have demonstrated improvement in postoperative pain and morbidity with the use of endoscopic techniques. METHODS: This study included 100 consecutive patients (45 women and 55 men) with an average follow-up evaluation of 4 years (range, 2-6 years). The average age of the patients was 42 years (range, 22-76 years). The average duration of symptoms was 26 months (range, 6-96 months), and 18 patients had undergone prior spine surgery. Patients were graded as follows according to the presenting symptoms (Table 1): Grade 1 (pure axial; n = 28), Grade 2 (pure radicular; n = 5), Grade 3A (axial and thoracic radicular; n = 38), Grade 3B (axial with lower leg pain; n = 19), Grade 4 (myelopathic; n = 8), or Grade 5 (paralytic = 2). RESULTS: A total of 117 discs were excised in 100 patients. Of the 40 patients who underwent fusion, 27 had autologous rib struts and 13 had threaded fusion. The mean operative time was 173 minutes, blood loss 259 mL, average ICU stay less than 1 day, and average hospital stay 4 days. Minor complications occurred in 21 patients, all of which resolved with no untoward effect. No patient's neurologic status worsened. Four patients underwent a secondary fusion, and a pseudarthrosis developed in one patient. Clinical success was defined objectively as an improvement in Oswestry score of 20% or more at 2 years and at final follow-up assessment, as compared with the preoperative Oswestry score. Overall, objective clinical success was observed at 2 years in 73% of the patients, and at final follow-up assessment in 70% of patients. The average percentage of improvement in Oswestry scores was most marked in Grade 4 patients (myelopathy; 60%), followed by Grade 3A patients (axial and thoracic radicular pain; 37%), Grade 3B patients (axial with leg pain; 28%), and Grade 1 patients (pure axial; 24%). The Oswestry disability score (Table 2) and back pain visual analog score (Table 3) also were significantly improved (P < 0.05) at 2 years and at final follow-up assessment in these patients. In the Grade 2 patients, those pure thoracic radicular pain, Oswestry scores initially improved significantly up to 1 year (P < 0.05). At 2 years, no significant improvement could be shown, and four of the five Grade 2 patients reported increased axial pain as their main symptom at the final follow-up assessment. Significant improvement also was seen in patients with no prior spine surgery and patients with preoperative Oswestry disability scores greater than 50. Of the 68 patients who responded to the final questionnaire, 12 rated the procedure as excellent, 37 as good, 11 as fair, and 8 as poor. Also, 57 (83.8%) of these 68 patients were satisfied and indicated they would recommend the surgery. Of the 36 patients at the final follow up assessment who had severe disability, 34 (94%) were satisfied, as compared with 23 of the 32 patients (72%) who had presented with milder disability. CONCLUSIONS: The clinical classification system helps in differentiating different presentations of thoracic disc disease and their final outcome. Video-assisted thorascopic surgery appears to be a safe and efficacious method for the treatment of refractory symptomatic thoracic disc herniations. The current data suggest that the procedure has an acceptable long-term outcome, with an 84% overall subjective patient satisfaction rate, and with objective long-term clinical success achieved in 70% of patients.

Title Mediating Denials of Pharmaceutical Services: an Alternative to Traditional Appeals.
Date April 2002
Journal American Journal of Health-system Pharmacy : Ajhp : Official Journal of the American Society of Health-system Pharmacists
Excerpt

The effectiveness of mediation as a primary tool to resolve pharmaceutical service denials by managed care is discussed. A three-month prospective randomized trial of 48 medical appeal cases involving prescription drugs was conducted by Tennessee's Department of Health. Patients whose prescription claims were denied by the state's Medicaid managed care program and whose appeals were deemed medically unnecessary by one of two independent reviewers were randomly assigned to either a standard procedure group or a mediation group. Appeals assigned to the standard procedure group were immediately referred for administrative hearing. In the mediation group, the independent reviewer assigned to the case contacted the patient's care provider, discussed the case, and recommended an alternative drug. The care provider either accepted the suggested compromise, concluding the appeals process, or declined the suggestion, allowing the appeal to go to hearing. Reviewers recorded the amount of time they spent on each appeal. The mediation did not substantially increase the time the reviewers spent on each case (mean +/- S.D. minutes, 15.83+/-7.89 mediation versus 12.26+/-6.96 standard procedure). The mean number of appealed drugs was also similar between groups (1.46+/-0.78 mediation versus 1.35+/-0.89 standard procedure). Only 21% of appealed cases went to hearings in the mediation group, while 80% did in the standard procedure group. The average cost to the state for employing mediation ($142.92+/-$186.77) was significantly lower than the average cost incurred by using standard procedures ($355.75+/-$175.43). Mediation is an effective and efficient tool for resolving patients' appeals of denied pharmaceutical services.

Title Thoracoscopic Microdiscectomy.
Date April 2002
Journal Neurosurgery
Excerpt

The thorascopic approach for the microsurgical removal of herniated thoracic discs is described, and perioperative management is also discussed. The microsurgical techniques used for decompression of the spinal canal in the thoracic spine are presented in detail. The diagnostic imaging, surgical positioning, approach, port placement, localization of the thoracic level, exposure of the surgical field, excision of the rib head, exposure with removal of the herniated disc, and postoperative management are outlined. Surgical and operative "pearls" in thoracoscopic spinal surgery for removing herniated thoracic discs when possible are described and illustrated.

Title Laparoscopic Approach to L4-l5 for Interbody Fusion Using Bak Cages: Experience in the First 58 Cases.
Date November 1999
Journal Spine
Excerpt

STUDY DESIGN: Operative reports were reviewed for patients who underwent laparoscopic fusion at the L4-L5 level and information regarding the mobilization of the vessels was recorded. OBJECTIVE: The purpose of this study was to describe variations in the approach used to address anatomical variations in the location of the great vessel bifurcation in the region of the L4-L5 intervertebral disc space when performing laparoscopic interbody fusion procedures. SUMMARY OF BACKGROUND DATA: Recent interest in laparoscopic spine surgery using threaded cages has resulted in questions regarding the ability to safely access the L4-L5 disc using this approach. The laparoscopic transperitoneal approach to L5-S1 is below the bifurcation of the great vessels, thus requiring minimal mobilization of the iliac vessels. However, the transperitoneal approach to L4-L5 may be complicated by the bifurcation of the great vessels anterior to this disc space. Difficulty in placing two cages may occur if the vessels cannot be adequately mobilized. METHODS: Data were collected for the consecutive series of the first 58 patients (40 males, 18 females; mean age 42.5 years) undergoing laparoscopic anterior lumbar interbody fusion (ALIF) at the L4-L5 level using BAK cages. Operative notes were reviewed to determine variations in the operative approach. In particular, it was recorded if the L4-L5 disc was accessed above, or below the bifurcation of the aorta and the vena cava, or between these structures. The blood loss, operative time, and length of hospitalization were compared with respect to approach variation. RESULTS: In 30 patients, the L4-L5 disc was accessed above the great vessel bifurcation, in 18 patients below the bifurcation, and in the remaining 10 patients, by passing between the vessels. There were no statistically significant differences in the operative time, blood loss, or length of hospitalization with respect to the approach used. Three patients were converted to open procedures as a result of bleeding from segmental veins. None required transfusions and there were no postoperative sequelae. In two patients, successful endoscopic repair of segmental vein avulsion from the vena cava was performed using endoscopic loop ligatures. One patient had a secondary procedure to remove a cage that was causingnerve irritation, and one patient reported retrograde ejaculation after a two level fusion. Another patient, in whom a posterior herniation was removed, later presented with a cerebrospinal fluid leak. Most of the operative complications occurred early in the series. CONCLUSIONS: Laparoscopic transperitoneal approach to L4-L5 for insertion of threaded fusion cages is feasible. The laparoscopic L4-L5 procedure can be accomplished with few complications, provided a dedicated team of collaborative surgeons with experience in laparoscopic spine techniques is employed. Variations in vascular anatomy did not prevent successful insertion of two threaded fusion cages.

Title Reoperation for Herniated Thoracic Discs.
Date October 1999
Journal Journal of Neurosurgery
Excerpt

OBJECT: In this review the authors address the surgical strategies required to resect residual herniated thoracic discs. METHODS: Data obtained in 15 patients who had undergone prior thoracic discectomy and who harbored residual or incompletely excised symptomatic thoracic discs were reviewed retrospectively. The surgical procedures that had failed to excise the herniated discs completely included 11 posterolateral approaches, one thoracotomy, and three thoracoscopy-guided surgical procedures. Of the lesions that were incompletely resected or residual, there were 13 central calcified, two soft. 12 extradural, and three intradural discs. Indications for reoperation were often multiple in each patient and included misidentification of the level of disc disease at the initial operation (five cases), abandoning the procedure because of intraoperative spinal cord injury (three cases), inadequate visualization of the pathological entity (eight cases), migration of a soft disc fragment within the spinal canal (one case), and intradural disc extension (three cases). The symptoms at the time of reoperation included myelopathy in 13 patients and radicular pain in two patients. The mean interval before reoperation was 150 days (range 1 day-4 years). The reoperation procedures included one thoracotomy and 14 video-assisted thoracoscopic procedures performed ipsilateral (11 cases) or contralateral (four cases) to the site of the initial surgery. The herniated disc material was excised completely in all 15 cases without causing new neurological deficits. Reoperation complications included atelectasis in three patients, intercostal neuralgia in two, a loosened screw that required removal in one, residual intradural disc herniation that required a second reoperation in one patient, and a cerebrospinal fluid leak in one patient. Of the 13 patients who experienced myelopathy prior to operation, 10 recovered neurological function and three stabilized. All patients with radicular pain improved. CONCLUSIONS: Calcified, large, broad-based, centrally located, or transdural thoracic disc herniations can be difficult to resect. These lesions require a ventral operative approach to visualize the dura adequately for a safe and complete resection.

Title Laparoscopic Fusion of the Lumbar Spine: Minimally Invasive Spine Surgery. A Prospective Multicenter Study Evaluating Open and Laparoscopic Lumbar Fusion.
Date April 1999
Journal Spine
Excerpt

Two hundred-forty consecutive patients underwent laparoscopic instrumented interbody fusion using custom-designed instrumentation and BAK (Sulzer Spine Tech, Minneapolis, MN) fusion cages. The surgeries were performed at eight spine centers during U.S. Food and Drug Administration investigational device evaluation clinical trials. This cohort was compared with 591 consecutive patients undergoing open anterior fusion with the same device.

Title Minimally Invasive Anterior Retroperitoneal Approach to the Lumbar Spine. Emphasis on the Lateral Bak.
Date September 1998
Journal Spine
Excerpt

STUDY DESIGN: Eighteen patients with lumbar instability from fractures, postlaminectomy syndrome, or infection were treated prospectively with minimally invasive retroperitoneal lumbar fusions. OBJECTIVES: To determine if interbody Bagby and Kuslich fusion cages and femoral allograft bone dowels can be inserted in a transverse direction via a lateral endoscopic retroperitoneal approach to achieve spinal stability. SUMMARY OF BACKGROUND DATA: Endoscopic spinal approaches have been used to achieve lower lumbar fusion when instrumentation is placed through a laparoscopic, transperitoneal route. However, complications of using this approach include postoperative intra-abdominal adhesions, retrograde ejaculation, great vessel injury, and implant migration. This study is the first clinical series investigating the use of the lateral retroperitoneal minimally invasive approach for lumbar fusions from L1 to L5. METHODS: Eighteen patients underwent anterior interbody decompression and/or stabilization via endoscopic retroperitoneal approaches. In most cases, three 12-mm portals were used. Two parallel transverse interbody cages restored the neuroforaminal height and the desired amount of lumbar lordosis was achieved by inserting a larger anterior cage, distraction plug, or bone dowel. RESULTS: The overall morbidity of the procedure was lower than that associated with traditional "open" retroperitoneal or laparotomy techniques, with a mean length of hospital stay of 2.9 days (range, outpatient procedure to 5 days). The mean estimated intraoperative blood loss was 205 cc (range, 25-1000 cc). There were no cases of implant migration, significant subsidence, or pseudoarthrosis at mean follow-up examination of 24.3 months (range, 12-40 months) after surgery. CONCLUSIONS: This preliminary study of 18 patients illustrates that endoscopic techniques can be applied effectively through a retroperitoneal approach with the patient in the lateral position. Unlike the patients who had undergone transperitoneal procedures described in previous reports, in these preliminary 18 patients, there were no cases of retrograde ejaculation, injury to the great vessels, or implant migration.

Title Video-assisted Thoracoscopic Excision of Herniated Thoracic Disc: Description of Technique and Preliminary Experience in the First 29 Cases.
Date September 1998
Journal Journal of Spinal Disorders
Excerpt

This study evaluates the technique and results of video-assisted thoracoscopic surgery (VATS) for the treatment of symptomatic thoracic disc herniation. Results were compared with a literature review of open surgical techniques of thoracic disc excision with regard to efficacy, safety, and surgical outcomes. VATS has recently been described for thoracic surgery as having the advantage of decreased postoperative pain and morbidity, faster patient recovery, and shortened intensive care unit (ICU) hospitalization. Twenty-nine consecutive patients underwent VATS for symptomatic thoracic disc herniation. Herniations ranging from T5-6 to T12-L1 were successfully approached by using a three- or four-portal strategy. Postoperative magnetic resonance imaging (MRI) scans were evaluated. Pre- and postoperative Oswestry Disability Questionnaires and Linear Analog Pain Scale data were obtained. Patients were grouped according to presenting symptoms. The minimal follow-up was 1 year (range, 12-24 months). Mean operative time was 175 min for 29 patients. Significant improvement (p < 0.01, paired t test) was recorded in Oswestry Disability Questionnaires and Linear Analog Scale Tests. Of the patients, 75.8% (22) were satisfied, 3.4% (one) unsatisfied, with 20.1% (six) unchanged. Narcotic use was significantly eliminated or reduced. Mean return to work was 5 weeks (private insurance) and 21 weeks (workers compensation). The surgical and postoperative complication rate was 13.8%. VATS appears to be a safe and efficacious method of excising herniated thoracic discs. Follow-up results at 1 year resulted in high patient satisfaction. VATS advantages include decreased length of hospitalization as well as improved patient comfort.

Title Pathways for Electron Tunneling in Cytochrome C Oxidase.
Date August 1998
Journal Journal of Bioenergetics and Biomembranes
Excerpt

Warburg showed in 1929 that the photochemical action spectrum for CO dissociation from cytochrome c oxidase is that of a heme protein. Keilin had shown that cytochrome a does not react with oxygen, so he did not accept Warburg's view until 1939, when he discovered cytochrome a3. The dinuclear cytochrome a3-CuB unit was found by EPR in 1967, whereas the dinuclear nature of the CuA site was not universally accepted until oxidase crystal structures were published in 1995. There are negative redox interactions between cytochrome a and the other redox sites in the oxidase, so that the reduction potential of a particular site depends on the redox states of the other sites. Calculated electron-tunneling pathways for internal electron transfer in the oxidase indicate that the coupling-limited rates are 9 x 10(5) (CuA-->a) and 7 x 10(6) s(-1) (a-->a3); these calculations are in reasonable agreement with experimental rates, after corrections are made for driving force and reorganization energy. The best CuA-a pathway starts from the ligand His204 and not from the bridging sulfur of Cys196, and an efficient a-a3 path involves the heme ligands His378 and His376 as well as the intervening Phe377 residue. All direct paths from CuA to a3 are poor, indicating that direct CuA-->a3 electron transfer is much slower than the CuA-->a reaction. The pathways model suggests a means for gating the electron flow in redox-linked proton pumps.

Title Electron Tunneling in Azurin: the Coupling Across a Beta-sheet.
Date January 1998
Journal Chemistry & Biology
Excerpt

We would like to understand how electron flow is controlled in biological molecules. Standard theories calculate the rate for long distance electron transfer (ET) as the product of electronic coupling (the square of the electron tunneling matrix element) and nuclear (Franck-Condon) factors. Much attention has been directed to the role of protein secondary and tertiary structure in the tunneling coupling, focusing on the interplay between different types of chemical bonds. Here we have evaluated the relative contributions of covalent bonds, hydrogen bonds and through-space jumps in coupling through a beta-strand or across a beta-sheet section of a blue copper protein, azurin.

Title Minimally Invasive Approaches to the Spine.
Date June 1997
Journal Instructional Course Lectures
Title Minimally Invasive Arthroscopic Spinal Surgery.
Date June 1997
Journal Instructional Course Lectures
Title Laparoscopic Fusion of the Lumbar Spine in a Multicenter Series of the First 34 Consecutive Patients.
Date March 1997
Journal Surgical Laparoscopy & Endoscopy
Excerpt

The purpose of this study was to describe the development of the laparoscopic technique for anterior lumbar fusion and to evaluate the clinical results of a first case series of patients. The in vivo porcine model was used first to develop the technique of transperitoneal laparoscopic interbody fusion. Afterwards, operative time, blood loss, perioperative complications and length of stay were recorded for the first 34 patients who underwent laparoscopic fusion of L4-5 or L5-S1 at two medical centers in 1994. Laparoscopic lumbar fusion was successful in 30 of 34 patients. Four patients early in the series successfully were converted to an open procedure because of poor visualization (two cases) or iliac venous injury (two cases). Transfusion was required in one patient; average blood loss was 128 ml. Operative time averaged 218 min, hospitalization 3.67 days. Laparoscopic fusion is feasible and has minimal complications when a skilled laparoscopic surgeon is present for exposure. Minimal excisional trauma associated with this technique should result in decreased hospitalization and earlier recovery compared with standard open techniques. Preliminary results indicate an earlier discharge and return to work (3 weeks) than that expected for standard open techniques.

Title Endoscopic Techniques in Spinal Surgery.
Date February 1997
Journal Clinical Orthopaedics and Related Research
Excerpt

Minimally invasive techniques are becoming more widespread in the surgical subspecialties. Standard open surgical procedures are being modified to become less invasive, with the hopes of decreased recovery time, lessened morbidity, and ultimately, cost savings. Improvements in technology have allowed the surgeon to peer into body cavities and create potential spaces such as the retroperitoneum and the neuroforaminal space without the need for traditional extensile surgical approach. Improved fiberoptics, light sources, and the advent of the 3-chip camera and the 3-dimensional camera have resulted in improvements in visualization of the structures surrounding the spine. Although the goals of endoscopic surgery are to maintain or improve visualization and minimize the approach related trauma, procedures must also prove efficacious and safe with at least equivalent results compared with their open surgical counterpart. Not all procedures may be applicable to minimally invasive approaches and just because a procedure can be done does not mean that it should be done. Laparoscopic and thoracoscopic spine procedures also depend on the partnership of the spine surgeon with the thoracic or general surgeon with endoscopic experience to ensure patient safety. Proficiency in minimally invasive spinal techniques takes devotion and does not occur after taking minicourses. Practice with cadaver and in vivo models, preceptorship and proctorship training, and ultimately the teaching of these techniques in residency and spinal fellowship programs will undoubtedly lead to favorable outcomes and reduced medical expenditure. Preliminary results are encouraging for endoscopic spinal surgery, but further testing of these new techniques against conventional open procedures will be important in documenting not only the efficacy of the procedure, but also its value in patient satisfaction and cost.

Title Percutaneous Endoscopic Thoracic Discectomy.
Date December 1996
Journal Neurosurgery Clinics of North America
Excerpt

Video-assisted thoracic surgery (VATS) appears to be a safe and efficacious method of excising herniated thoracic discs. Results indicate high patient satisfaction rates comparable to those of open thoracotomy. VATS' advantages include decreased length of hospitalization, decreased postoperative pain, less shoulder girdle dysfunction, lower incidence of pulmonary complications and post-thoracotomy syndrome, and earlier return to normal activity when compared to thoracotomy approaches.

Title Pathways, Pathway Tubes, Pathway Docking, and Propagators in Electron Transfer Proteins.
Date October 1996
Journal Journal of Bioenergetics and Biomembranes
Excerpt

The simplest views of long-range electron transfer utilize flat one-dimensional barrier tunneling models, neglecting structural details of the protein medium. The pathway model of protein electron transfer reintroduces structure by distinguishing between covalent bonds, hydrogen bonds, and van der Waals contacts. These three kinds of interactions in a tunneling pathway each have distinctive decay factors associated with them. The distribution and arrangement of these bonded and nonbonded contacts in a folded protein varies tremendously between structures, adding a richness to the tunneling problem that is absent in simpler views. We review the pathway model and the predictions that it makes for protein electron transfer rates in small proteins, docked proteins, and the photosynthetic reactions center. We also review the formulation of the protein electron transfer problem as an effective two-level system. New multi-pathway approaches and improved electronic Hamiltonians are described briefly as well.

Title Video-assisted Thoracic Surgery for the Anterior Approach to the Thoracic Spine.
Date May 1995
Journal The Annals of Thoracic Surgery
Excerpt

Standard anterior approach to the thoracic spine is by a posterolateral thoracotomy. Because of the morbidity associated with this incision, video-assisted thoracic surgery (VATS) has been used as a less invasive approach for many intrathoracic disease processes. We have applied VATS for anterior access to the thoracic spine. From April 1991 to September 1994, 95 patients underwent thoracic spine procedures using thoracoscopy as the sole method of anterior approach. Procedures performed include discectomy for herniation (n = 57), multilevel discectomy for correction of spinal deformity (27), corpectomy (9), and drainage of intervertebral disc space abscess (2). All levels of the thoracic spine from the T2-T3 level to the T12-L1 interspace were approached. Forty-four procedures were performed through the left side of the chest and 41 through the right. The planned procedure was accomplished by VATS in all but 1 patient who required conversion to an open procedure because of scarring from a previous spine procedure. Mean operative time was 2 hours 24 minutes (range, 45 minutes to 5 hours 10 minutes). Average chest tube duration was 1.4 days, and mean length of stay was 4.82 days (range, 2 to 21 days). Complications included intercostal neuralgia (6), atelectasis (5), excessive epidural blood loss (2,500 mL; 2) and temporary paraparesis in a scoliosis patient related to operative positioning. We conclude that VATS offers a new, less morbid anterior approach to the thoracic spine. Although there is a significant learning period, most procedures requiring an anterior access can be performed safely by this technique. The VATS approach mandates an expanded role for the thoracic surgeon in operative spine disease.

Title A Technical Report on Video-assisted Thoracoscopy in Thoracic Spinal Surgery. Preliminary Description.
Date May 1995
Journal Spine
Excerpt

STUDY DESIGN. This report is a preliminary description of the efficacy of video-assisted thoracoscopic surgery in thoracic spinal procedures that otherwise require open thoracotomy. OBJECTIVE. This report sought to describe the efficacy of video-assisted thoracoscopic surgery in thoracic spinal procedures that otherwise require open thoracotomy. SUMMARY OF BACKGROUND DATA. In a landmark study that compared video-assisted thoracoscopic surgery for peripheral lung lesions with thoracotomy, video-assisted thoracoscopic surgery reduced postoperative pain, improved early shoulder girdle function, and shortened hospital stay. METHODS. Video-assisted thoracoscopic surgery was performed in 12 thoracic spinal patients (herniated nucleus pulposus, infection, tumor, or spinal deformity) and is described in detail in this report. RESULTS. Video-assisted thoracoscopic surgery in thoracic spinal surgery resulted in little postoperative pain, short intensive care unit and hospital stays, and little or no morbidity. In the short follow-up period, there was no post-thoracotomy pain syndrome nor neurologic sequelae in these patients. Operative time decreased dramatically as experience was gained with the procedure. CONCLUSION. Given consistently improving surgical skills, a number of thoracic spinal procedures using video-assisted thoracoscopic surgery, including thoracic discectomy, internal rib thoracoplasty, anterior osteotomy, corpectomy, and fusion, can be performed safely with no additional surgical time or risk to the patient.

Title Clinical Features of Situational and Nonsituational Major Depression.
Date December 1993
Journal Psychopathology
Excerpt

Clinical lore has long supported the subtype of situational or reactive depression. To date, however, there has been limited empirical research support for this subtype of major depression. We examined demographic, clinical and personality features of situational and nonsituational depression in 89 outpatients with unipolar nonpsychotic major depressive disorder. Situational depressives had a less recurrent course of illness and appeared to respond more completely to the antidepressant used for their current episode. Demographic and personality measures did not distinguish situational and nonsituational depression.

Title Application of Thoracoscopy for Diseases of the Spine.
Date October 1993
Journal The Annals of Thoracic Surgery
Excerpt

For anterior approaches to the thoracic spine, a posterolateral thoracotomy has been the standard approach. Recent expanded experience with video-assisted thoracic surgical techniques has allowed us to perform many thoracic spine procedures that previously required open approaches. These procedures include drainage of spinal abscesses, biopsy of vertebral bodies, discectomy for a herniated nucleus pulposus, and anterior releases for kyphoscoliosis. All procedures were successful, but experience is limited and follow-up still short. It is hoped that further experience will prove that this less invasive approach can be widely applied in the practice of thoracic spinal surgery.

Title The Tridimensional Personality Questionnaire in Major Depression.
Date June 1993
Journal The American Journal of Psychiatry
Excerpt

The authors examined Tridimensional Personality Questionnaire scores in 40 patients with unipolar nonpsychotic major depression before and after antidepressant treatment. They found that scores on the novelty seeking and reward dependence dimensions were not affected by depressed state or by treatment response status. However, scores on the harm avoidance dimension were significantly lower in antidepressant responders and were altered by depressed state.

Title The Biomechanical and Histomorphometric Properties of Anterior Lumbar Fusions: a Canine Model.
Date April 1992
Journal Journal of Spinal Disorders
Excerpt

An in vivo model was developed to compare the biomechanical stability, incidence of radiographic union, bone formation rate, and bone graft remodeling parameters of anterior interbody fusions. Eighteen 1-year-old beagles underwent anterior and posterior spinal destabilization procedures at L5-L6 to produce a reproducible amount of spinal instability--resection of the anterior longitudinal ligament, L5-L6 intervertebral disk, L5 and L6 lamina, spinous processes, zygoopophyseal joints, and ligamentum flavum. Group I (N = 6) were surgically destabilized controls; Group II (N = 6) underwent anterior L5-L6 interbody fusion with iliac crest bone graft; and Group III (N = 6) underwent anterior stabilization with a longitudinal fibular strut graft in addition to the same operative procedure as Group II. Six months postoperatively the group with the highest incidence of successful radiographic L5-L6 arthrodesis was Group III, anterior interbody fusion and fibular stabilization (p less than .10). The rank order of biomechanical stability was the same for the three groups for both torsional and axial compressive stiffness, with Group I (destabilized controls) being the least rigid, then Group II (anterior fusion with iliac crest grafting only), and the most rigid to both torsion and axial compressive loading was Group III (anterior fusion with fibular stabilization and iliac crest bone graft). The bone formation rate [mm3/(mm3 x year) x 10(3)], which was derived from the distance between fluorochrome markers, revealed that the more stable the individual spinal construct, the lower the bone formation rate. In summary, the beagle provided a successful model for studying in vivo the response of anterior bone grafts over a 6-month interval and provided comparative biomechanical and histomorphometric data on spinal interbody fusion techniques.

Title The Effect of Sensory Deprivation in the Reduction of Pain in Patients with Chronic Low-back Pain.
Date July 1991
Journal Spine
Excerpt

Patients who suffer from persistent pain for prolonged periods of time (6 months or more) are often influenced to an increasing extent by psychological factors. Patients begin to focus on their pain as the problem rather than its physical origin. This study evaluated the effectiveness of sensory deprivation in reducing pain in patients with chronic low-back pain. Sixty patients were divided into two groups of 30 patients each: One group underwent 1 hour of sensory deprivation; the other received a lecture on relaxation skills. In the group receiving sensory deprivation, statistically significant decreases in pain and stiffness were noted. Sensory deprivation is an effective treatment to reduce pain and thus interrupt the pain cycle in patients with chronic low-back pain.

Title Personality and Family History of Depression in Patients with Affective Illness.
Date June 1991
Journal Journal of Psychiatric Research
Excerpt

The presence of a family history of depression may distinguish clinically important subgroups of depressed patients. Depressed patients with and without a family history of depression may differ on several clinical features. There are limited data, however, on potential differences in personality variables between patients with and without familial depression. We examined personality measures in 41 depressed subjects with and without a familial history of depression in both the depressed and remitted state. Patients with no family history of depression had significantly higher mean personality trait scores on the dependent and compulsive personality scales. The clinical and theoretical implications of these findings are discussed.

Title Financial Planning for Health Care in Older Age: Implications for the Delivery of Health Services.
Date December 1990
Journal Law, Medicine & Health Care : a Publication of the American Society of Law & Medicine
Title Personality and Response to Tricyclic Antidepressants in Depressed Patients.
Date January 1990
Journal The Journal of Nervous and Mental Disease
Excerpt

Several studies have shown that disturbances of personality are poor predictors of response to antidepressants. None of these studies, however, has used personality measures similar to the DSM-III. We evaluated the relationship between antidepressant response and personality scores obtained on the Millon Clinical Multiaxial Inventory, which provides personality measures congruent with DSM-III. Personality features such as assertiveness, independence, and competitiveness distinguished responders from nonresponders. However, the frequency of personality disorder diagnoses did not differ between responders and nonresponders.

Title Physicians and Their Elderly Patients' Legal Rights, Part I: Medicare, Medicaid, Elder Abuse. Panel Discussion.
Date September 1989
Journal Geriatrics
Title Personality and Suicidal Behavior in Depressed Patients.
Date April 1989
Journal Comprehensive Psychiatry
Excerpt

The relationship between personality and suicidal behavior was evaluated in 53 patients with primary major depressive disorder. Mean borderline personality scale scores on the Millon Clinical Multiaxial Inventory (MCMI) differed between suicide attempters and non-attempters. The frequency of personality disorder diagnoses, especially borderline personality disorder, was not higher in the suicide attempters. Clinical and theoretical implications of these findings are discussed.

Title Personality and Depression.
Date March 1989
Journal Journal of Psychiatric Research
Excerpt

Several studies suggest that measures of personality traits and disorders are affected by depressed state. However, none of the studies to date have evaluated the effect of depressed mood on personality using current diagnostic criteria. The effect of depressed mood on personality scale scores and personality disorder diagnoses using the Millon Clinical Multiaxial Inventory was assessed in 42 depressed patients. There was a significant alteration in mean personality trait scores and reduction in personality disorder diagnosis between the depressed and remitted states. The clinical and theoretical implications of these findings are discussed.

Title Discitis After Discography.
Date February 1989
Journal Spine
Excerpt

A series of nine patients with post-discography discitis were evaluated to help delineate the clinical course. The most consistent sign was the marked exacerbation of neck or back pain. This then was followed by an elevated sedimentation rate at an average of 20 days, followed by a positive bone scan at an average of 33 days. Of note is that seven patients initially had negative bone scans at an average of 18 days. Five out of nine patients had changes on plain roentgenograms between 14 and 51 days after discography. Magnetic resonance imaging was performed in six patients; two of these patients were scanned twice. Three scans were negative and five were positive (2 patients initially had negative scans that later became positive). The course of lumbar discitis ranged from 8 to 11 weeks, and cervical discitis from 6 to 7 weeks, with the latter usually resulting in spontaneous fusion.

Title Personality Features of Obsessive-compulsive Disorder.
Date September 1988
Journal The American Journal of Psychiatry
Excerpt

The authors evaluated personality dysfunction in 23 patients with primary obsessive-compulsive disorder and an age- and sex-matched group of patients with major depressive disorder. There were no significant differences between the two patient groups with respect to mean personality trait scores or the frequency or type of personality disorder diagnosis. A mixed personality disorder with avoidant, dependent, and passive-aggressive features was most commonly observed in the obsessive-compulsive group. There was a very low frequency of schizoid or compulsive personality disorder.

Title Cervical Cord Compression from Ossification of the Posterior Longitudinal Ligament in Non-orientals.
Date September 1987
Journal The Journal of Bone and Joint Surgery. British Volume
Excerpt

We report 14 cases of symptomatic ossification of the posterior longitudinal ligament (OPLL) diagnosed in non-oriental men between 1978 and 1985. All 14 patients had incomplete spinal cord syndromes due to OPLL in the cervical spine and had been referred undiagnosed from other institutions. Twelve had severe myelopathy and seven were wheelchair-bound before OPLL was diagnosed, while six patients had had operations elsewhere for their neurological dysfunction. There was a close association between OPLL and diffuse idiopathic skeletal hyperostosis (Forestier's disease) on plain radiographs, seven patients having both disorders. Enhanced CT scans proved to be the best diagnostic method for the localisation of cord compression, and magnetic resonance imaging, used on four recent cases, provided the best visualisation of the extent of involvement in the sagittal plane. We aim to heighten awareness of OPLL in non-orientals, in whom the clinical features, histological characteristics, and radiographic patterns are very similar to those of oriental patients.

Title Reversible Renal Resistance to Aldosterone Associated with Interstitial Nephritis.
Date August 1987
Journal The Western Journal of Medicine
Title Refusal to Treat: Can It Be Justified? A Mount Sinai Cpc.
Date July 1987
Journal Geriatrics
Title The Induction of Cardiac Arrhythmia and Hypotension from Spinal Cord Monitoring. A Case Report.
Date May 1987
Journal Spine
Title Process and Context: Hidden Factors in Health Care Decisions for the Elderly.
Date January 1986
Journal Law, Medicine & Health Care : a Publication of the American Society of Law & Medicine
Title Influence of Fructose on the Glycogen Synthase and Phosphorylase Systems in Rat Liver.
Date December 1980
Journal Metabolism: Clinical and Experimental
Excerpt

Fructose and glucose, when administered as a single, large intravenous dose (500 mg/kg) produced opposite effects on key regulatory enzymes of glycogen metabolism in intact normal fed animals. Glucose rapidly stimulated glycogen synthase phosphatase activity and increased the proportion of glycogen synthase in the active (I) form as expected; fructose reduced synthase phosphatase activity and the proportion of synthase in the I form. Glucose also stimulated a reduction in the proportion of phosphorylase in the active (a) form, whereas fructose stimulated an increase in the proportion of phosphorylase in thea form. The effect of fructose was not mediated by an increase in cyclic adenylate (cAMP) concentration nor by a conversion of phosphorylase kinase b to phosphorylase kinase a. As expected, the concentration of ATP decreased significantly. The increase in proportion of phosphorylase in the a form may be due to stimulation of phosphorylase kinase b activity by a decrease in the intracellular ATP:Mg++ ratio or by increase in intracellular Ca++ concentration. The mechanism of the fructose-induced change in synthase phosphatase activity and in synthase I activity is unknown.

Title Intervention Through Adult Protective Services Programs.
Date August 1978
Journal The Gerontologist
Title Commentaries on Cha Guidelines: the Limits of Loyalty.
Date July 1975
Journal Hospital Progress
Title Valediction.
Date October 1974
Journal Minnesota Medicine
Title Hmo.
Date February 1974
Journal Minnesota Medicine
Title Shortening the Hospital Stay.
Date January 1974
Journal Minnesota Medicine
Title Spatial Dark-soliton Stripes and Grids in Self-defocusing Materials.
Date
Journal Physical Review Letters
Title Prospective, Randomized, Multicenter Food and Drug Administration Investigational Device Exemption Study of Lumbar Total Disc Replacement with the Charite Artificial Disc Versus Lumbar Fusion: Five-year Follow-up.
Date
Journal The Spine Journal : Official Journal of the North American Spine Society
Excerpt

BACKGROUND CONTEXT: The CHARITE artificial disc, a lumbar spinal arthroplasty device, was approved by the United States Food and Drug Administration in 2004 based on two-year safety and effectiveness data from a multicenter, prospective, randomized investigational device exemption (IDE) study. No long-term, randomized, prospective study on the CHARITE disc or any other artificial disc has been published to date. PURPOSE: The purpose of this study was to compare the safety and effectiveness at the five-year follow-up time point of lumbar total disc replacement using the CHARITE artificial disc (DePuy Spine, Raynham, MA) with that of anterior lumbar interbody fusion (ALIF) with BAK cages and iliac crest autograft, for the treatment of single-level degenerative disc disease from L4 to S1, unresponsive to nonoperative treatment. STUDY DESIGN/SETTING: Randomized controlled trial-five-year follow-up. PATIENT SAMPLE: Ninety CHARITE patients and 43 BAK patients. OUTCOME MEASURES: Self-reported measures: visual analog scale (VAS); validated Oswestry disability index (ODI version 1.0); Short-Form 36 Questionnaire, and patient satisfaction. Physiologic measures: radiographic range of motion, disc height, and segmental translation. Functional measures: work status. METHODS: Of the 375 subjects enrolled in the CHARITE IDE trial, 277 were eligible for the five-year study and 160 patients thereof completed the five-year follow-up. The completers included 133 randomized patients. Overall success was defined as improvement>/=15pts in ODI vs. baseline, no device failure, absence of major complications, and maintenance or improvement of neurological status. Additional clinical outcomes included an ODI questionnaire as well as VAS, SF-36, and patient satisfaction surveys. Work status was tracked for all patients. Safety assessments included occurrence and severity of adverse events and device failures. Radiographic analyses such as index- and adjacent-level range of motion, segmental translation, disc height, and longitudinal ossification were also carried out. RESULTS: Overall success was 57.8% in the CHARITE group vs. 51.2% in the BAK group (Blackwelder's test: p=0.0359, Delta=0.10). In addition, mean changes from baseline for ODI (CHARITE: -24.0pts vs. BAK: -27.5pts), VAS pain scores (CHARITE: -38.7 vs. BAK: -40.0), and SF-36 questionnaires (SF-36 Physical Component Scores [PCS]: CHARITE: 12.6pts vs. BAK: 12.3pts) were similar across groups. In patient satisfaction surveys, 78% of CHARITE patients were satisfied vs. 72% of BAK patients. A total of 65.6% patients in the CHARITE group vs. 46.5% patients in the BAK group were employed full-time. This difference was statistically significant (p=0.0403). Long-term disability was recorded for 8.0% of CHARITE patients and 20.9% of BAK patients, a difference that was also statistically significant (p=0.0441). Additional index-level surgery was performed in 7.7% of CHARITE patients and 16.3% of BAK patients. Radiographic findings included operative and adjacent-level range of motion (ROM), intervertebral disc height and segmental translation. At the five-year follow-up, the mean ROM at the index level was 6.0 degrees for CHARITE patients and 1.0 degrees for BAK patients. Changes in disc height were also similar for both CHARITE and BAK patients (0.7mm for both groups, p=0.9827). Segmental translation was 0.4 and 0.8mm in patients implanted with CHARITE at L4-L5 vs. L5-S1, respectively, and 0.1mm in BAK patients. CONCLUSIONS: The results of this five-year, prospective, randomized multicenter study are consistent with the two-year reports of noninferiority of CHARITE artificial disc vs. ALIF with BAK and iliac crest autograft. No statistical differences were found in clinical outcomes between groups. In addition, CHARITE patients reached a statistically greater rate of part- and full-time employment and a statistically lower rate of long-term disability, compared with BAK patients. Radiographically, the ROMs at index- and adjacent levels were not statistically different from those observed at two-years postsurgery.

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