BACKGROUND: The goals were to compare the morbidity and mortality between primary and revisional bariatric surgery and to identify the clinical predictors of adverse outcomes among patients undergoing revisional surgery in the Longitudinal Assessment of Bariatric Surgery consortium. The study was multi-institutional at university hospitals in the United States. METHODS: Data from the LABS-1 (safety) cohort were analyzed, excluding primary gastric banding patients. A total of 3802 LABS-1 patients were included: 3577 who underwent primary surgery and 225 who underwent revisional surgery. The demographic, clinical, operative, and 30-day outcome data were compared between the 2 groups. A nonlinear mixed effects logit model was used to identify independent risk factors for adverse outcomes (death, deep vein thrombosis, pulmonary embolism, reintubation, reoperation, or discharge after 30 days). RESULTS: Compared with those undergoing revisional surgery, the primary surgery patients were younger (median age 44 versus 49 years, P <.0001) and more likely to be male (20.5% versus 12.7%, P =.006) and heavier (median body mass index 47.3 versus 41.2 kg/m(2), P <.0001) and to have more co-morbidities (P <.0001), including hypertension (56.0% versus 46.0%, P =.0044), diabetes (35.7% versus 20.0%, P <.0001), and sleep apnea (50.3% versus 27.2%, P <.0001). The operative time for the revisional procedures was longer (median 181 versus 135 min, P <.0001) and associated with greater blood loss (median 100 versus <50 mL, P <.0001). Adverse outcomes were more likely after revisional surgery (15.1% versus 5.3%, P <.0001, odds ratio 2.4, 95% confidence interval 1.6-3.6). After adjusting for patient characteristics previously shown to be associated with adverse outcomes, this difference remained statistically significant (odds ratio 2.3, 95% confidence interval 1.5-3.8). The 30-day mortality rate was similar in the 2 groups (.4%). CONCLUSION: Revisional surgery was performed without substantial mortality but with a greater incidence of adverse outcomes than was primary bariatric surgery.

BACKGROUND: Bariatric surgery is technically demanding surgery performed on high-risk patients. Previous studies using administrative databases have shown a relationship between surgeon volume and patient outcome after Roux-en-Y gastric bypass (RYGB). We examined the relationship between surgeons' annual RYGB volumes and 30-day patient outcomes at 10 centers within the United States. METHODS: The Longitudinal Assessment of Bariatric Surgery (LABS)-1 is a prospective study examining the 30-day adverse outcomes after bariatric surgery. The outcomes after RYGB were adjusted by procedure type (open versus laparoscopic), functional status, body mass index, history of deep vein thrombosis, pulmonary embolism, and obstructive sleep apnea. The data were examined to determine the nature and strength of the association between surgeon volume and patients' short-term (30-day) adverse outcomes after RYGB. RESULTS: The analysis included 3410 initial RYGB operations performed by 31 surgeons, 15 of whom averaged <50 cases annually. The crude composite adverse outcome (i.e., death, deep vein thrombosis, pulmonary embolism, reintervention or nondischarge at day 30) incidence was 5.2%. After risk adjustment, a greater surgeon RYGB volume was associated with lower composite event rates, with a continuous relationship (i.e., varying cutpoints differentiated the composite event rates), such that for each 10-case/yr increase in volume, the risk of a composite event decreased by 10%. CONCLUSION: In the LABS, the patient's risk of an adverse outcome after RYGB decreased significantly with the increase in surgeon RYGB volume (cases performed annually).

BACKGROUND: The obesity epidemic causes significant morbidity and mortality. Knowledge of cellular function and gene expression in obese adipose tissue will yield insights into obesity pathogenesis and suggest therapeutic targets. The aim of this work is to study the processes determining fat accumulation in adipose tissue from obese patients. METHODS: Omental fat was collected from two cohorts of obese bariatric surgery patients and sex-matched normal-weight donors. Isolated adipocytes were compared for cell size, volume, and long-chain fatty acid (LCFA) uptake. Omental fat RNAs were screened by 10K microarray (cohort 1: three obese, three normal) or Whole Genome microarray (cohort 2: seven obese, four normal). Statistical differences in gene and pathway expression were identified in cohort 1 using the GeneSifter Software (Geospiza) with key results confirmed in cohort 2 samples by microarray, quantitative real-time polymerase chain reaction, and pathway analysis. RESULTS: Obese omental adipocytes had increased surface area, volume, and V (max) for saturable LCFA uptake. Dodecenoyl-coenzyme A delta isomerase, central to LCFA metabolism, was approximately 1.6-fold underexpressed in obese fat in cohorts 1 and 2. Additionally, the Kyoto Encyclopedia of Genes and Genomics pathway analysis identified oxidative phosphorylation and fatty acid metabolism pathways as having coordinate, nonrandom downregulation of gene expression in both cohorts. CONCLUSIONS: In obese omental fat, saturable adipocyte LCFA uptake was greater than in controls, and expression of key genes involved in lipolysis, beta-oxidation, and metabolism of fatty acids was reduced. Thus, both increased uptake and reduced metabolism of LCFAs contribute to the accumulation of LCFAs in obese adipocytes.

BACKGROUND: Although the procedure is generally safe, significant morbidity and even mortality have occurred after laparoscopic donor nephrectomy (LDN). The learning curves for both surgeons and institutions with LDN have not been well delineated, and longterm donor data are not well reported. STUDY DESIGN: A retrospective study of the initial 512 patients undergoing LDN performed at Mount Sinai Medical Center between October 1996 and March 2006 was performed. Intraoperative and immediate postoperative surgical outcomes were reviewed. Univariate analysis and multivariate logistic regressions were performed to identify predictors of outcomes, including the experience level of individual surgeons and of the institution. Longitudinal followup data of donor patients between 1 month and 9 years were obtained. RESULTS: Mean donor age was 39.2 years, and 54.6% of patients were women. Left kidneys were procured in 84.0%. Operative time averaged 215.2 minutes, and warm ischemia time, 166.6 seconds. The conversion rate was 1.4%, and hand-assistance was used in 49.9%. The intraoperative complication rate was 5.5%, 30-day complication rate 9.4%, and 1.4% of patients required reoperation. Immediate graft survival was 97.1%, acute tubular necrosis occurred in 8.5%, and delayed graft function in 3.7%. At a mean followup of 37.2 months, delayed donor complications were infrequent, but included chronic pain, hypertension, incisional hernia, and small bowel obstruction. Although individual surgeons and our institution gained experience, operative and warm ischemia times decreased significantly, but complication rates were unchanged. CONCLUSIONS: Although a learning curve was discovered for operative time and warm ischemia time, excellent results can be achieved during the early experience of both surgeons and institutions with LDN, and maintained over time. Younger, female, and nonobese donors were associated with fewer complications. Longterm donor morbidity is uncommon, but mandates better followup.

BACKGROUND: To improve decision making in the treatment of extreme obesity, the risks of bariatric surgical procedures require further characterization. METHODS: We performed a prospective, multicenter, observational study of 30-day outcomes in consecutive patients undergoing bariatric surgical procedures at 10 clinical sites in the United States from 2005 through 2007. A composite end point of 30-day major adverse outcomes (including death; venous thromboembolism; percutaneous, endoscopic, or operative reintervention; and failure to be discharged from the hospital) was evaluated among patients undergoing first-time bariatric surgery. RESULTS: There were 4776 patients who had a first-time bariatric procedure (mean age, 44.5 years; 21.1% men; 10.9% nonwhite; median body-mass index [the weight in kilograms divided by the square of the height in meters], 46.5). More than half had at least two coexisting conditions. A Roux-en-Y gastric bypass was performed in 3412 patients (with 87.2% of the procedures performed laparoscopically), and laparoscopic adjustable gastric banding was performed in 1198 patients; 166 patients underwent other procedures and were not included in the analysis. The 30-day rate of death among patients who underwent a Roux-en-Y gastric bypass or laparoscopic adjustable gastric banding was 0.3%; a total of 4.3% of patients had at least one major adverse outcome. A history of deep-vein thrombosis or pulmonary embolus, a diagnosis of obstructive sleep apnea, and impaired functional status were each independently associated with an increased risk of the composite end point. Extreme values of body-mass index were significantly associated with an increased risk of the composite end point, whereas age, sex, race, ethnic group, and other coexisting conditions were not. CONCLUSIONS: The overall risk of death and other adverse outcomes after bariatric surgery was low and varied considerably according to patient characteristics. In helping patients make appropriate choices, short-term safety should be considered in conjunction with both the long-term effects of bariatric surgery and the risks associated with being extremely obese.(ClinicalTrials.gov number, NCT00433810.)

BACKGROUND: A paucity of information is available on the comparative body composition changes after bariatric procedures. The present study reports on the body mass index (BMI) and body composition changes after 4 procedures by a single group. METHODS: At the initial consultation, the weight and body composition of the patients undergoing 4 different bariatric procedures were measured by bioimpedance (Tanita 310). Follow-up examinations were performed at 1 year and at subsequent visits after surgery. Analysis of variance was used to compare the postprocedure BMI and body composition. Analysis of covariance was used to adjust for baseline differences. RESULTS: A total of 101 gastric bypass (GB) patients were evaluated at 19.1 +/- 10.6 months, 49 biliopancreatic diversion with the duodenal switch (BPD/DS) patients at 27.5 +/- 16.3 months, 41 adjustable gastric band (AGB) patients at 21.4 +/- 9.2 months, and 30 sleeve gastrectomy (SG) patients at 16.7 +/- 5.6 months (P <.0001). No differences were found in patient age or gender among the 4 groups. The mean preoperative BMI was significantly different among the 4 groups (P <.0001): 61.4 kg/m(2), 53.2, 46.7, and 44.3 kg/m(2) for the SG, BPD/DS, GB, and AGB group, respectively. The postoperative BMI adjusted for baseline differences was 27.8 (difference 23.6 +/- 8.3), 32.5 (difference 15.6 +/- 5.0), 37.2 (difference 18.2 +/- 8.2), and 39.5 kg/m(2)(difference 7.5 +/- 4.3) for the BPD/DS, GB, SG, and AGB groups, respectively (P <.0001). The percentage of excess weight loss was 84%, 70%, 49%, and 38% for the BPD/DS, GB, SG, and AGB groups, respectively (P <.0001). The postoperative percentage of body fat adjusted for baseline differences was 25.7%(23.9%+/- 7.0%) 32.7%(16.1%+/- 10.5%) 37.7%(16.7%+/- 5.6%), and 42%(6.0%+/- 6.8%) for the BPD/DS, GB, SG, and AGB groups, respectively (P <.0001). The lean body mass changes were reciprocal. CONCLUSION: Although the BPD/DS procedure reduced the BMI the most effectively and promoted fat loss, all the procedures produced weight loss. The AGB procedure resulted in less body fat loss within 21.5 months than SG within 16.7 months. Longer term observation is indicated.

Much has been published over the last few years about sleeve gastrectomy. It is a bariatric operation that has evolved from both established restrictive and malabsorptive procedures. Originally used as a bridge to definitive surgery in high-risk patients, it has recently been forwarded as a stand-alone procedure. Technical details of laparoscopic sleeve gastrectomy (LSG) vary, but the premise is removal of the vast majority of the stomach, especially the fundus, leaving only a thin gastric tube between the esophagus and the duodenum. This results in weight loss from restrictive as well as neurohormal mechanisms. Review of the literature reveals an average expected excess weight loss (EWL) of 61%. Morbidity and mortality seem to be on par with laparoscopic adjustable gastric banding (LAGB), but with superior weight loss results and an improved long-term complication profile. Unlike popular mixed malabsorptive procedures like Roux en-Y gastric bypass (RYGB) and biliopancreatic diversion with duodenal switch (BPD-DS), there is no gastrointestinal segment exclusion, maintaining continuity for endoscopic interventions and surveillance. Comorbidity resolution with LSG is variable, though compares favorably with other bariatric procedures. While the early results seem promising, long-term data is still needed to define the place of LSG within the bariatric surgery armamentarium.

SUMMARY Objective: To assess vitamin D status and the influences of race, sun exposure and dietary vitamin D intake on vitamin D levels, and to evaluate two vitamin D repletion regimens in extremely obese patients awaiting bariatric surgery. Methods: A cross-sectional analysis of dietary vitamin D, sun exposure, parathyroid hormone (iPTH and PTH[1-84]) and 25-hydroxyvitamin D (25OHD; differentiated 25OHD(2) and 25OHD(3)) in 56 obese (BMI>35kg/m(2)) men and women (20-64 yrs). In a pilot clinical trial, 27 subjects with 25OHD levels <62 nmol/L were randomized to receive ergocalciferol or cholecalciferol for 8 weeks. Results: Serum 25OHD was low (mean 45+/-22 nmol/L), and was inversely associated with BMI (r=-0.36; p<0.01). Each BMI increase of 1kg/m(2) was associated with a 1.3nmol/L decrease in 25OHD (p<0.01). BMI, sun exposure, African American race, and PTH predicted 40% of the variance in 25OHD (p<0.0001). Serum 25OHD significantly increased at 4 and 8 weeks in both treatment groups (p<0.001), while PTH(1-84) declined significantly in subjects treated with cholecalciferol (p<0.007), and tended to decrease following ergocalciferol (p<0.09). Conclusions: In severely obese individuals, those who are African American, have higher BMI and limited sunlight exposure are at greatest risk for vitamin D insufficiency. These demographic factors can help identify at risk patients who require vitamin D repletion prior to bariatric surgery. Commonly prescribed doses of ergocalciferol and cholecalciferol are effective in raising 25OHD. Further investigation is needed to evaluate whether these regimens have differential effects on PTH, and to determine the optimal regimen for vitamin D repletion in the extremely obese patient.