Browse Health
Surgical Specialist, Cardiothoracic Surgeon
12 years of experience
Accepting new patients

Education ?

Medical School Score Rankings
University of Minnesota, Twin Cities (1998)
  • Currently 4 of 4 apples
Top 25%

Awards & Distinctions ?

Appointments
Stanford Hospital & Clinics
Associations
American Board of Surgery
American Board of Thoracic Surgery

Affiliations ?

Dr. Hoang is affiliated with 3 hospitals.

Hospital Affilations

Score

Rankings

  • Stanford Hospital and Clinics
    Thoracic Surgery (Cardiothoracic Vascular Surgery)
    300 Pasteur Dr, Stanford, CA 94305
    • Currently 1 of 4 crosses
  • El Camino Hospital
    Thoracic Surgery (Cardiothoracic Vascular Surgery)
    2500 Grant Rd, Mountain View, CA 94040
    • Currently 1 of 4 crosses
  • Stanford Med Center
  • Publications & Research

    Dr. Hoang has contributed to 16 publications.
    Title Tumor Volume As a Potential Imaging-based Risk-stratification Factor in Trimodality Therapy for Locally Advanced Non-small Cell Lung Cancer.
    Date September 2011
    Journal Journal of Thoracic Oncology : Official Publication of the International Association for the Study of Lung Cancer
    Excerpt

    The role of trimodality therapy for locally advanced non-small cell lung cancer (NSCLC) continues to be defined. We hypothesized that imaging parameters on pre- and postradiation positron emission tomography (PET)-computed tomography (CT) imaging are prognostic for outcome after preoperative chemoradiotherapy (CRT)/resection/consolidation chemotherapy and could help risk-stratify patients in clinical trials.

    Title Technology-enhanced Interactive Surgical Education.
    Date December 2006
    Journal The Journal of Surgical Research
    Excerpt

    BACKGROUND: Our goal was to create surgical resident centered, interactive teaching modules rich in basic science and clinical content directly pertinent to patient care and surgical techniques that would facilitate education in the 80-h work week environment. METHODS: A systematic evaluation of available instructional tools determined that a technology-enhanced approach can effectively and efficiently address the new requirements for resident learning. An extensive evaluation of available technology determined the technology best suited to teaching the adult surgical learner. RESULTS: An on-line, multimedia-based surgical education environment using WebCT Vista (WebCT, Inc., Lynnfield, MA) and Macromedia Breeze (Adobe Systems, Inc., San Jose, CA) software packages was implemented. The concept was constructed on tenets of adult learning theory and based on the APDS curriculum and ACGME core competencies. WebCT Vista serves as virtual scaffolding, and Macromedia Breeze functions to deliver content rich multimedia audio and visual presentations. Core subdiscipline teaching modules were created, comprised of individual lecture packets developed by faculty. Components for testing pre/post module knowledge, feedback and evaluations are built-in. The online nature allows for 24-h access at locations that are convenient to the resident. CONCLUSIONS: Teaching modules enable maximal trainee and instructor flexibility, which translates into optimal adult learning and teaching. Lecture packets can be conveyed to all residents with unlimited availability in the virtual domain. Further refinement and continued implementation will help fill the void in direct didactic teaching left by mandated work hour restrictions, allowing for more efficient learning and teaching. There is great potential for broad application of the concept and technology to other training programs.

    Title Wedge Gastroplasty and Reinforced Crural Repair: Important Components of Laparoscopic Giant or Recurrent Hiatal Hernia Repair.
    Date November 2006
    Journal The Journal of Thoracic and Cardiovascular Surgery
    Excerpt

    OBJECTIVE: Laparoscopic repair of a giant hiatal hernia (>50% of the stomach above the diaphragm) is associated with short-term recurrence rates of 12% to 42%. Recurrent hiatal hernias often have significantly altered anatomy, making laparoscopic repair challenging. We hypothesized that increasing intra-abdominal esophageal length by means of Collis wedge gastroplasty, complete fat-pad dissection, hernia-sac excision, and primary reinforced crural repair would minimize short-term recurrence and provide adequate symptomatic relief. METHODS: From January 1, 2001, though May 1, 2005, 61 patients underwent laparoscopic repair of a giant or recurrent hiatal hernia with a Collis wedge gastroplasty and Nissen fundoplication. Symptomatic outcomes were assessed with a validated questionnaire (Gastroesophageal Reflux Disease Health-Related Quality of Life). We obtained postoperative radiographic imaging to objectively assess anatomic results at a median of 1.13 years. RESULTS: Of the 61 patients, 12 (20%) were referred to our institution after previous repairs. Operating time averaged 308 +/- 103 minutes. The median hospital stay was 4 days. Postoperative complications occurred in 5 (8.2%) patients. One (1.6%) patient died of cardiac complications. Postoperatively, 52 (85%) patients completed the questionnaire with mean a Gastroesophageal Reflux Disease Health-Related Quality of Life questionnaire score of 1.15 +/- 2.78 (scale, 0-45; 0 = asymptomatic). Overall, 51 (98%) of the 52 respondents were satisfied with their surgical outcome. Postoperative radiographic data were available for 54 (89%) patients. We identified no recurrences at 1-month follow-up, and only 4.7% (2/42) had evidence of radiographic recurrence at 1 year or more. CONCLUSIONS: Consistent use of a Collis wedge gastroplasty with reinforced crural repair minimizes short-term recurrence after minimally invasive giant hiatal hernia repair. Symptomatic results are excellent in most patients.

    Title Analysis of Paired Primary Lung and Lymph Node Tumor Cells: a Model of Metastatic Potential by Multiple Genetic Programs.
    Date March 2006
    Journal Cancer Detection and Prevention
    Excerpt

    BACKGROUND: The current paradigm of metastasis proposes that rare cells within primary tumors acquire metastatic capability via sequential mutations, suggesting that metastases are genetically dissimilar from their primary tumors. We tested this hypothesis by examining the molecular differences, if any, between primary tumor cells and matched lymph node metastatic cells in human non-small-cell lung carcinoma specimens. METHODS: We performed transcriptional profiling studies on malignant cells from 11 pairs of stage III tumors and their tumor-positive lymph nodes using multiple, complementary analytic techniques. To confirm the overall validity of microarray data, we used real-time polymerase chain reaction. RESULTS: The molecular signature of nodal metastasis was a composite of two paradoxical, but not mutually exclusive, expression patterns: metastatic cells are: (1) different from their primary tumor cells based on a few genes and (2) genetically similar, overall, to their primary tumor cells. Consequently, we found a 27-gene subset sufficient to differentiate nodal metastatic cells from primary tumor cells. CONCLUSIONS: Thus, we concluded that a more accurate model of metastatic potential is based on a global primary tumor expression pattern along with the appearance of distinct metastatic variants. The 27-gene signature differentiating primary tumors from their metastatic cells may define non-small-cell lung carcinoma nodal metastatic potential.

    Title An Unusual Rectosigmoid Mass: Endometrioid Adenocarcinoma Arising in Colonic Endometriosis: Case Report and Literature Review.
    Date November 2005
    Journal The American Surgeon
    Excerpt

    Malignant transformation is an infrequent complication of endometriosis. The ovary is the primary site in 79 per cent of cases, and extragonadal sites are identified in 21 per cent. Primary involvement of these types of tumors with the colon and/or rectum is a rare clinical entity. Endometrioid carcinoma is a common histologic type that remains a diagnostic challenge-the main differential diagnosis includes colorectal carcinomas. We report a case of malignant transformation arising in colonic endometriosis. The patient had a total abdominal hysterectomy and bilateral salpingo-oophorectomy 10 years before she presented with hematochezia. The patient was ultimately treated by surgical resection. Immunohistochemical staining in addition to the usual histopathology was critical for accurate diagnosis of this endometriosis-associated intestinal tumor.

    Title Short Esophagus and Esophageal Stricture.
    Date August 2005
    Journal The Surgical Clinics of North America
    Excerpt

    Short esophagus and peptic esophageal stricture are complications of chronic severe GERD. Short esophagus is properly diagnosed by an objective,intraoperative assessment after appropriate dissection of the GEJ. A laparoscopic Collis gastroplasty combined with an antireflux procedure comprises effective therapy. Peptic stricture should be addressed with an initial course of dilator therapy and optimization of antiacid medication.Consideration is given to an antireflux procedure if conservative therapy fails.Laparoscopic techniques have proven to be safe and effective in treating short esophagus and peptic stricture.

    Title Selective Activation of Insulin Receptor Substrate-1 and -2 in Pleural Mesothelioma Cells: Association with Distinct Malignant Phenotypes.
    Date December 2004
    Journal Cancer Research
    Excerpt

    Molecular mechanisms active in transforming human pleural cells remain incompletely understood. Our previous microarray analysis of malignant pleural mesothelioma revealed alterations in components of the insulin-like growth factor (IGF) system, implicating this signaling axis in tumorigenesis. Therefore, in this current study, we characterized the molecular phenotype and investigated the key signaling pathways of the IGF system in malignant pleural mesothelioma specimens. For the major IGF components, we assessed mRNA abundance and total protein levels. We measured IGF-I ligand-dependent activation of signaling pathways downstream of the type I IGF receptor in a subset of malignant pleural mesothelioma cell lines and determined the corresponding biological consequences. At the transcriptional level, we observed consistent changes in IGF components that may contribute to a malignant phenotype. IGF-I stimulation of cells resulted in enhanced activation of type I IGF receptor and IRS adaptor proteins. Differential activation of IRS-1 signaling was associated with cell growth, whereas IRS-2 signaling was associated with cell motility. Thus, these data suggest that multiple mechanisms likely contribute to malignant pleural mesothelioma tumorigenesis. Therefore, IGF system components represent novel malignant pleural mesothelioma therapeutic targets for investigation.

    Title Return to Work After Thoracic Surgery: an Overlooked Outcome Measure in Quality-of-life Studies.
    Date October 2004
    Journal Thoracic Surgery Clinics
    Excerpt

    In the literature on thoracic surgery, return to work has received little attention in QOL investigations. At present, it is difficult to appreciate clinically meaningful trends in return to work after thoracic surgery, even within a specialized area, such as lung cancer resection. It is evident, however, that return to work is not a simple variable, easily measured; rather, it is a complex construct that is influenced by a multitude of personal and societal factors. Focusing only on disease-related or treatment-related symptoms renders QOL studies limited in scope and perhaps in usefulness. Return to work is not a trivial component of global postsurgical QOL; it should be recognized as a major factor. Patients have indicated that maintaining return-to-work ability is as highly valued as their overall health. Surgical societies should design, validate, and implement a simple data collection instrument to characterize better return to work after thoracic surgery.

    Title Situs Inversus Totalis: Giant Hiatal Hernia Repair by Laparoscopic Collis Gastroplasty and Nissen Fundoplication.
    Date August 2004
    Journal Surgical Endoscopy
    Excerpt

    We report the repair of a giant hiatal hernia by laparoscopic Collis gastroplasty and Nissen fundoplication in a patient with situs inversus totalis, highlighting the unique anatomic challenges in this case. The 52-year old female patient had Kartageners syndrome, a giant hiatal hernia, and a history of chronic severe gastroesophageal reflux disease with uncontrolled regurgitation. The laparoscopic procedure was accomplished with five ports placed in a mirror-image configuration, reversed from our standard positions. After visual confirmation of the complete reversal of the intraabdominal anatomy, we performed a modified Collis gastroplasty and Nissen fundoplication. Significant technical challenges were encountered intraoperatively. To the best of our knowledge, this report is the first of its kind in the literature. The use of advanced laparoscopic techniques is highly adaptable to unusual anatomy. Laparoscopic hiatal hernia surgery is feasible in patients with situs inversus.

    Title Gene Expression Profiling Identifies Matriptase Overexpression in Malignant Mesothelioma.
    Date July 2004
    Journal Chest
    Excerpt

    STUDY OBJECTIVE: We investigated the gene expression profiles of malignant pleural mesothelioma (MPM) specimens to identify novel genes that are potentially involved in the oncogenic transformation of human pleural cells. DESIGN: Complementary DNA (cDNA) microarray transcriptional profiling studies of 10 MPM cell lines and 4 MPM primary tumor specimens were performed using hierarchic clustering. To confirm microarray data, we used real-time polymerase chain reaction and immunoblotting. RESULTS: Cluster analysis differentiated among epithelial (E), sarcomatoid, and biphasic MPM variants. Expression profiling identified common overexpressed or underexpressed genes in MPM. Notably, matriptase messenger RNA was found to be overexpressed by 826-fold in E MPM, with protein expression subsequently confirmed by immunoblot analysis. This recently characterized trypsin-like serine protease has been implicated in tumor invasion and metastasis of E-derived cancers, but has not been described until now in MPM. We also identified other novel genes, such as insulin-like growth factor binding protein 5 and a cDNA clone similar to proteolipid MAL2. CONCLUSIONS: Thus, further large-scale profiling of MPM may elucidate previously unrecognized molecular mechanisms by identifying novel genes that are involved in malignant transformation. Our study has now found matriptase to be one of these mesothelioma-associated genes, with potential pathogenic and therapeutic significance.

    Title Complications of Chronic Pelvic Radiation Injury.
    Date July 2004
    Journal Journal of the American College of Surgeons
    Title Expression Profiling of Non-small Cell Lung Carcinoma Identifies Metastatic Genotypes Based on Lymph Node Tumor Burden.
    Date May 2004
    Journal The Journal of Thoracic and Cardiovascular Surgery
    Excerpt

    OBJECTIVE: This study hypothesized that non-small cell lung carcinoma cells from primary tumors isolated by laser capture microdissection would exhibit gene expression profiles associated with graded lymph node metastatic cell burden. METHODS: Non-small cell lung carcinoma tumors (n = 15) were classified on the basis of nodal metastatic cell burden by 2 methods, obtaining 3 groups: no metastasis, micrometastasis, and overt metastasis. We then performed microarray analysis on microdissected primary tumor cells and identified gene expression profiles associated with graded nodal tumor burden using a correlation-based selection algorithm coupled with cross-validation analysis. Hierarchical clustering showed the regrouping of tumor specimens; the classification inference was assessed with Fisher's exact test. We verified data for certain genes by using another independent assay. RESULTS: The 15 specimens clustered into 3 groups: cluster A predominated in specimens with overt nodal metastasis; cluster B had more specimens with nodal micrometastases; and cluster C included only specimens without nodal metastases. Cluster assignment was based on a validated 75-gene discriminatory subset. Notably, genes not previously associated with positive non-small cell lung carcinoma lymph node status were encountered in the profiling analysis. CONCLUSIONS: Microdissection, combined with microarray analysis, is a potentially powerful method to characterize the molecular profile of tumor cells. The 75-gene expression profiles representative of clusters A and B may define genotypes prone to metastasize. Overall, the 3 groups of tumor specimens clustered separately, suggesting that this approach may identify graded metastatic propensity. Further, genes singled out in clustering may yield insights into underlying metastatic mechanisms and may represent new therapeutic targets.

    Title Gene Expression Profiles in Esophageal Adenocarcinoma.
    Date April 2004
    Journal The Annals of Thoracic Surgery
    Excerpt

    BACKGROUND: The incidence of esophageal adenocarcinoma (EAC) has risen dramatically in the last two decades. As with other malignancies, changes in gene expression play a key role in the development and progression of these tumors. METHODS: Microarray analysis was used to study gene expression of 12,000 genes in EAC specimens. Adenocarcinoma tissue samples (n = 10) and controls of normal stomach (n = 6) and esophageal (n = 7) mucosa were collected fresh, then rapidly frozen in liquid nitrogen. The messenger ribonucleic acid (mRNA) from the samples was isolated, reverse transcribed, and used to generate biotin-labeled mRNA fragments, which were hybridized to Affymetrix U95 gene chips (AME Bioscience, Norway) for analysis. Additional samples analyzed included tissue containing dysplastic Barrett's epithelium from three patients, metastatic lymph nodes from two patients with EAC, one squamous carcinoma, and two esophageal cancer cell lines. Samples were segregated into groups with similar patterns of gene expression using clustering algorithms and gene sets that differentiated tumors from normal tissue were generated. RESULTS: There were 150 genes that were fourfold up regulated and 183 genes that were fourfold down regulated in the esophageal adenocarcinoma specimens, as compared to normal esophageal mucosa tissue controls. Using paired specimens (n = 5) and the paired t-test (p Value of 0.05) as a filter, only 64 genes were fourfold up regulated and 110 were fourfold down regulated. These groups included cytoskeletal, cell adhesion, tumor suppressor, and signal transduction genes. Hierarchical clustering segregated the samples into the expected divisions. The esophageal cancer cell lines, OE19 and OE33, clustered separately from the EAC specimens. Extremely high gene expression levels of the ERBB2 gene, seen in the microarray analysis of the 2 cell lines, correlated with amplification of the gene determined by Southern blotting. CONCLUSIONS: Gene expression patterns from a small subset of genes distinguish EAC specimens from normal controls. This technique can rapidly identify genes for targeted chemotherapeutic approaches to cancer treatment.

    Title Reports of Pain by Children Undergoing Rapid Palatal Expansion.
    Date September 2000
    Journal Pediatric Dentistry
    Excerpt

    PURPOSE: This study described and quantified the prevalence, timing, and intensity of pain during the expansion phase of rapid palatal expansion (RPE) in children and investigated whether pain was related to age, sex, or rate of expansion. METHODS: Ninety-seven children, 38 males and 59 females, between the ages of 5 to 13 years (median 7.7 years) undergoing RPE procedures with the Hyrax, Dentaurum, Newtown, PA, appliance were surveyed. The appliance was expanded with either one or two turns (1/4 mm/turn) per day based on the provider's preference. The child's pain response was measured no more than 5 minutes after each turn for the entire period of expansion using both the Facial Pain Scale and the Color Analog Scale. RESULTS: Ninety-eight percent of the children reported at least some pain during RPE. The highest levels of pain were reported during the first 10 turns with the greatest intensity during the first 6 turns and a steadily decreasing amount of pain thereafter. Pain medication was taken after 7% of the expansion turns in the study with the majority of children taking the medication during the first 6 turns. Forty-eight percent of the children took pain medication at least once during the expansion phase of RPE. There was no difference in either reported pain or use of pain medication based on age, sex, or stage of dentition. During the first 10 turns, children whose rate of expansion was two turns/day were more likely to report pain and take pain medication than children whose rate of expansion was one turn/day, thereafter there were no differences. CONCLUSIONS: The vast majority of children undergoing the active phase of rapid palatal expansion with a Hyrax appliance report pain. The pain generally occurs during the initial phase of expansion and diminishes thereafter, with two turns/day resulting in reports of pain greater than those expanding only once/day.

    Title Post-infarction Left Ventricular Remodeling Induces Changes in Creatine Kinase Mrna and Protein Subunit Levels in Porcine Myocardium.
    Date July 1997
    Journal The American Journal of Pathology
    Excerpt

    Energy metabolism is altered in post-infarction remodeled pig myocardium. To understand the basis of this abnormality, we examined the pattern of creatine kinase (CK) gene expression and the relative content of CK protein subunits in pig hearts with proximal left circumflex coronary artery ligation. At 2 months after infarct, both Northern and Western blot analyses were performed on left ventricular myocardium remote from the infarct zone in ligation animals (n = 8). Results were compared with data from the left ventricular myocardium from similar sized normal (control) pigs (n = 7). Steady-state levels of mitochondrial CK mRNA decreased 46% in left ventricular remodeled (LVR) heart samples (93.40 +/- 18.60 arbitrary units) compared with controls (172.85 +/- 37.20 arbitrary units), whereas CK-M subunit mRNA levels remained unchanged between the control and LVR groups (319.50 +/- 35.25 and 352.50 +/- 62.18 arbitrary units, respectively). The mean control group CK-M protein subunits (2.04 +/- 0.31 arbitrary units) decreased 53% (P < 0.05) compared with the LVR group (0.95 +/- 0.25 arbitrary units). Similarly, the mean control group (n = 4) mitochondrial CK protein subunits (1.12 +/- 0.04 arbitrary units) decreased 30% (P < 0.05) compared with the LVR group (n = 4; 0.79 +/- 0.06 arbitrary units). Mean CK-B protein subunits in LVR pig hearts (0.84 +/- 0.23 arbitrary units) increased 77% compared with control (0.48 +/- 0.05 arbitrary units). The total CK activity did not change significantly between control hearts at 164 +/- 11 IU/mg and LVR at 212 +/- 32 IU/mg. We suggest that these alterations of the CK system represent the bioenergetic phenotype of LVR myocardium at the molecular level. The CK system response may ultimately prove inadequate in meeting the abnormal energy requirements of remodeled heart and, therefore, may contribute to the transition toward failure.

    Title Minimally Invasive Versus Open Roux-en-y Gastric Bypass: Effect on Immune Effector Cells.
    Date
    Journal Surgery for Obesity and Related Diseases : Official Journal of the American Society for Bariatric Surgery
    Excerpt

    BACKGROUND: Minimally invasive surgery (MIS) has several potential benefits compared with the open approach, including potentially less perioperative immunosuppression. Data characterizing the differential stress responses have been limited to serum cytokine analyses and animal studies. We hypothesized that the open approach to Roux-en-Y gastric bypass (RYGB) has a more deleterious, negative, quantifiable effect on the peripheral blood mononuclear cells than does the MIS approach. METHODS: Patients undergoing open and MIS RYGB for morbid obesity had blood samples collected preoperatively and postoperatively on days 1 and 2 and at the first follow-up visit. The peripheral blood mononuclear cells were isolated and analyzed for phenotype using flow cytometry, natural killer cell cytotoxicity using 51-chromium release assay, and gene expression using Affymetrix U133 Plus 2.0 microarray. RESULTS: Patient age and body mass index were similar between the 2 groups. Postoperatively, differences within the open group were seen for CD3+/CD16- (T lymphocytes), CD3-/CD16+ (natural killer cells), CD3+/CD4+ (T-helper lymphocytes), and CD4/CD8 subsets (P <.05). No differences were seen within the open group CD3+/CD8+ (cytotoxic T lymphocytes) or within the MIS subsets. Between the 2 approaches, no phenotypic differences were found, except for the postoperative day 1 CD3+/CD16- (P <.05). Within each group, significant decreases were found in cytotoxicity on days 1 and 2 compared with preoperatively (P <.05). The cytotoxicity seen after MIS had returned to the preoperative levels at the first follow-up visit, but the cytotoxicity after open RYGB had not (P <.05). Between the 2 groups, the open group had greater cytotoxic decreases than did the MIS group at postoperative days 1 and 2 (P <.05). Microarray analysis of the preoperative (n = 20) and day 2 (n = 20) specimens identified a 20-gene signature that correlated with the surgical approach. CONCLUSION: Open RYGB surgery causes greater inhibition of innate immunity than does MIS. This inhibition was not accounted for by phenotypic changes. Gene expression changes from surgical stress might represent the molecular basis of this differential immune response.

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