Brian Nguyen

Changes in the Makeup of Bariatric Surgery: A National Increase in Use of Laparoscopic Sleeve Gastrectomy

BACKGROUND Laparoscopic sleeve gastrectomy is gaining popularity in the US; however, there has been no study examining the use of sleeve gastrectomy at a national level and its impact on the use of other bariatric operations. The aim of this study was to examine contemporary changes in use and outcomes of bariatric surgery performed at academic medical centers. METHODS Using ICD-9 diagnosis and procedure codes, clinical data obtained from the University HealthSystem Consortium database for all bariatric procedures performed for the treatment of morbid obesity between October 1, 2008 and September 30, 2012 were reviewed. Quartile trends in use for the 3 most commonly performed bariatric operations were examined, and a comparison of perioperative outcomes between procedures was performed within a subset of patients with minor severity of illness. RESULTS A total of 60,738 bariatric procedures were examined. In 2008, the makeup of bariatric surgery consisted primarily of gastric bypass (66.8% laparoscopic, 8.6% open), followed by laparoscopic gastric banding (23.8%). In 2012, there was a precipitous increase in use of laparoscopic sleeve gastrectomy (36.3 %), with a concurrent reduction in the use of laparoscopic (56.4%) and open (3.2%) gastric bypass, and a major reduction in laparoscopic gastric banding (4.1%). The length of hospital stay, in-hospital morbidity and mortality, and costs for laparoscopic sleeve gastrectomy were found to be between those of laparoscopic gastric banding and laparoscopic gastric bypass. CONCLUSIONS Within the context of academic medical centers, there has been a recent change in the makeup of bariatric surgery. There has been an increase in the use of laparoscopic sleeve gastrectomy, which has had an impact primarily on reducing the use of laparoscopic adjustable gastric banding.

Outcomes of Bariatric Surgery Performed at Accredited vs Nonaccredited Centers

BACKGROUND In an effort to improve the quality of care in bariatric surgery, 2 accreditation programs based on volume have been initiated. The aim of this study was to analyze the perioperative outcomes of bariatric surgery performed at accredited vs nonaccredited centers. STUDY DESIGN Patient-level data obtained from the University HealthSystem Consortium for patients who underwent bariatric surgery for the treatment of morbid obesity between 2007 and 2009 were reviewed. Perioperative outcomes were analyzed according to accreditation status. The primary outcome was in-hospital mortality. Secondary outcomes included length of stay, 30-day readmission, overall complications, and cost. Comparisons of length of stay and cost were performed at the hospital-level data. RESULTS Of the 35,284 bariatric operations performed during the study period, 89.2% of cases were performed at 71 accredited centers; 10.8% of cases were performed at 43 nonaccredited centers. The rate of in-hospital mortality was significantly lower in accredited centers (0.06% vs 0.21%). Compared with nonaccredited centers, bariatric surgery performed at accredited centers was also associated with shorter length of stay (mean difference 0.3 days; 95% CI 0.16 to 0.44) and lower cost (mean difference,

Prevalence of hiatal hernia in the morbidly obese

3,758; 95% CI,

Integrated proteomic and transcriptomic analysis of the Aedes aegypti eggshell

2,965 to

Use of laparoscopy in general surgical operations at academic centers

3,952). Post-hoc analyses based on procedural type and severity of illness suggested possible associations between center accreditation and improved in-hospital mortality in patients who underwent gastric bypass and patients with higher severity of illness; similarly, patients requiring prolonged ICU or hospital stay (≥7 days) had significantly lower in-hospital mortality within accredited centers. CONCLUSIONS Within the context of academic centers, accreditation status was associated with lower in-hospital mortality. The lower mortality rate associated with accredited centers may be attributed to their ability to recognize and rescue complications.

Conformational selectivity in cytochrome P450 redox partner interactions

BACKGROUND Morbidly obese patients commonly have gastroesophageal reflux (GERD) and associated hiatal hernias. As such, some surgeons routinely perform a concomitant hiatal hernia repair during bariatric surgery. However, the intraoperative inspection for a hiatal hernia based on laparoscopic visualization can be misleading. The aim of this study was to assess the prevalence of hiatal hernias in morbidly obese patients based on preoperative upper gastrointestinal (GI) contrast study. METHODS Data on 181 patients who underwent routine upper GI contrast study as part of a preoperative workup for bariatric surgery were reviewed. The upper GI studies were examined for the presence of hiatal hernias and GERD. Hiatal hernias were categorized by size as small (≤2 cm), moderate (2-5 cm), or large (>5 cm). GERD was based on radiologic evidence and categorized as mild, moderate, or severe. RESULTS The mean age of the cohort was 44 years, with a mean body mass index of 43 kg/m(2). Of the 181 patients overall, based on the upper GI contrast study, the prevalence of hiatal hernia was 37.0% and of GERD was 39.8%; the prevalence of moderate or large hiatal hernia was 4.4%, and the prevalence of moderate or severe GERD was 13.3%. CONCLUSIONS Based on upper GI contrast study, we identified the presence of a hiatal hernia in nearly 40% of morbidly obese patients. The results from this study suggest that surgeons should evaluate the morbidly obese patient for the presence of hiatal hernias and perform concomitant repair at the time of the bariatric procedure, particularly in patients undergoing gastric banding and sleeve gastrectomy, while less so in the gastric bypass patient.

Risk factors for venous thromboembolism in critically ill trauma patients who cannot receive chemical prophylaxis

BackgroundMosquito eggshells show remarkable diversity in physical properties and structure consistent with adaptations to the wide variety of environments exploited by these insects. We applied proteomic, transcriptomic, and hybridization in situ techniques to identify gene products and pathways that participate in the assembly of the Aedes aegypti eggshell. Aedes aegypti population density is low during cold and dry seasons and increases immediately after rainfall. The survival of embryos through unfavorable periods is a key factor in the persistence of their populations. The work described here supports integrated vector control approaches that target eggshell formation and result in Ae. aegypti drought-intolerant phenotypes for public health initiatives directed to reduce mosquito-borne diseases.ResultsA total of 130 proteins were identified from the combined mass spectrometric analyses of eggshell preparations.ConclusionsClassification of proteins according to their known and putative functions revealed the complexity of the eggshell structure. Three novel Ae. aegypti vitelline membrane proteins were discovered. Odorant-binding and cysteine-rich proteins that may be structural components of the eggshell were identified. Enzymes with peroxidase, laccase and phenoloxidase activities also were identified, and their likely involvements in cross-linking reactions that stabilize the eggshell structure are discussed.

Strategic Laparoscopic Surgery for Improved Cosmesis in General and Bariatric Surgery: Analysis of Initial 127 Cases

BACKGROUND Laparoscopy is commonly being used in many different types of general surgical procedures. The aim of the present study was to examine the use of laparoscopy and perioperative outcomes in 7 general surgical operations commonly performed at U.S. academic medical centers. METHODS The clinical data of patients who underwent 1 of the 7 general surgical operations from 2008 to 2012 were obtained from the University HealthSystem Consortium database. The University HealthSystem Consortium database contains data from all major teaching hospitals in the United States. The 7 analyzed operations included only elective, inpatient procedures (except for appendectomy): open and laparoscopic antireflux surgery for gastroesophageal reflux, colectomy for colon cancer or diverticulitis, bariatric surgery for morbid obesity, ventral hernia repair for incisional hernia, appendectomy for acute appendicitis, rectal resection for rectal cancer, and cholecystectomy for cholelithiasis. The outcome measures included the number of procedures, rate of laparoscopy, rate of conversion to laparotomy, and in-hospital mortality. RESULTS During the 3.5-year period, 53,958 patients underwent bariatric surgery, 13,918 patients underwent antireflux surgery, 8654 patients underwent appendectomy, 8512 patients underwent cholecystectomy, 29,934 patients underwent colectomy, 17,746 patients underwent ventral hernia repair, and 4729 patients underwent rectal resection. The present rate of laparoscopic use was 94.0% for bariatric surgery, 83.7% for antireflux surgery, 79.2% for appendectomy, 77.1% for cholecystectomy, 52.4% for colectomy, 28.1% for ventral hernia repair, and 18.3% for rectal resection. In-hospital mortality was greatest for colorectal resection (.38%-.58%). In-hospital mortality for bariatric surgery (.06%) was comparable to that for appendectomy (.01%), cholecystectomy (.27%), antireflux surgery (.15%), and ventral hernia repair (.20%). The rate of laparoscopic conversion to open surgery was lowest for bariatric surgery (.89%) and greatest for rectal resection (16.4%). CONCLUSION Within the context of academic centers and elective, inpatient procedures, bariatric surgery had the greatest use of laparoscopy and the lowest rate of laparoscopic conversion to open surgery. The mortality for laparoscopic bariatric surgery is now comparable to that of laparoscopic cholecystectomy, ventral hernia repair, appendectomy, and antireflux surgery.

Does Primary Anastomosis with Diversion Have Any Advantages over Hartmann’s Procedure in Acute Diverticulitis?

Significance Cytochrome P450 activates molecular oxygen to hydroxylate various molecules. This process requires the transfer of electrons from a redox partner, which further requires formation of a specific protein–protein complex. A question of increasing importance is whether or not the interaction between the P450 and its redox partner results in functionally important structural changes required for activity. The present work addresses the question of whether the redox partner favors binding to a specific conformer. This question is critically important in understanding how P450s activate molecular oxygen. The heme iron of cytochromes P450 must be reduced to bind and activate molecular oxygen for substrate oxidation. Reducing equivalents are derived from a redox partner, which requires the formation of a protein–protein complex. A subject of increasing discussion is the role that redox partner binding plays, if any, in favoring significant structural changes in the P450s that are required for activity. Many P450s now have been shown to experience large open and closed motions. Several structural and spectral studies indicate that the well-studied P450cam adopts the open conformation when its redox partner, putidaredoxin (Pdx), binds, whereas recent NMR studies indicate that this view is incorrect. Given the relevance of this discrepancy to P450 chemistry, it is important to determine whether Pdx favors the open or closed form of P450cam. Here, we have used both computational and experimental isothermal titration calorimetry studies that unequivocally show Pdx favors binding to the open form of P450cam. Analyses of molecular-dynamic trajectories also provide insights into intermediate conformational states that could be relevant to catalysis.

Brominated Luciferins Are Versatile Bioluminescent Probes

BACKGROUND Standard venous thromboembolism (VTE) prevention for critically ill trauma patients includes sequential compression devices and chemical prophylaxis. When contraindications to anticoagulation are present, prophylactic inferior vena cava filters (IVCF) may be used to prevent pulmonary emboli (PE) in high-risk patients, but specific indications are lacking. We sought to identify independent predictors of VTE in critically-ill trauma patients who cannot receive chemical prophylaxis in order to identify a subset of patients who may benefit from aggressive screening and/or prophylactic IVCF placement. METHODS All trauma patients in the surgical ICU from 2008 to 2009 were prospectively followed. Patients with an ICU length of stay ≥2 days who had contraindications to prophylactic anticoagulation were included. Screening duplex exams were obtained within 48 h of admission and then weekly. CT-angiography for PE was obtained if clinically indicated. Patients were excluded if they did not receive a duplex or if they had a post-injury VTE prior to ICU admission. Data regarding VTE rates (lower extremity [LE] DVT or PE), demographics, past medical history (PMH), injuries, and surgeries were collected. Univariate and multivariable analyses were performed to identify independent predictors of VTE with a p<0.05. RESULTS 411 trauma patients with a mean age of 48 (SD 22) years and 8 (SD 9) ICU days were included. 72% were male and the mean ISS was 22 (SD 13). 30 (7.3%) patients developed VTE: 28 (6.8%) with LEDVT and 2 (0.5%) with PE. Risk factors for VTE with a p<0.2 on univariate analysis included: PMH of DVT, injury severity score (ISS), extremity fractures (Fx), and a pelvis or LE extremity Fx repair. After logistic regression, only PMH of DVT (OR=22.6) and any extremity Fx (OR=2.4) remained as independent predictors. CONCLUSION VTE occur in 7% of critically injured trauma patients who cannot receive chemical prophylaxis. Aggressive screening and/or prophylactic IVCF placement may be considered in patients with a PMH of DVT or extremity fractures when anticoagulation is prohibited.