Fellowship training influences learning curves for laparoscopic sleeve gastrectomy.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is the most commonly performed bariatric surgical procedure. Little is known about how surgeon training background influences the learning curve of this procedure. We examined operating times (OT), weight loss outcomes, and 30-day complications between surgeons with and without fellowship training in LSG. We hypothesize that post-residency training specific to LSG influences learning curves. METHODS: Surgeons from a single institution were split into two groups: those who had not completed fellowship training in LSG (NF, n = 3), and those who had completed LSG specific training in fellowship (SGF, n = 3). OTs, BMI changes at 1 year, and 30-day readmissions, reoperations, and complications were extracted for the first 100 LSG cases of each surgeon. Data were analyzed in bins of 20 cases. Comparisons were made between cohorts within a bin and between adjacent bins of the same surgeon cohort. Logistic regression analyses were performed of OT and weight loss outcomes. RESULTS: SGF surgeons showed no difference in OTs over their first 100 cases. NF surgeons had statistically significant increased OTs compared to SGF surgeons during their first 60 cases and progressively shortened OTs during that interval (109 min to 78 min, p < 0.001 for NF surgeons vs. 73 min to 69 min, SGF surgeons). NF surgeons had a significantly steeper slope for improvement in OT over case number. There was no correlation between case number and weight loss outcomes in either group, and no differences in 30-day outcomes between groups. CONCLUSION: Surgeons who trained to perform LSG in fellowship demonstrate faster and consistent OR times on their initial independent LSG cases compared to surgeons who did not, with no correlation between case number and weight loss outcomes or safety profiles for either group. This suggests that learning curves for LSG are achieved during formal case-specific fellowship training.

Sleeve gastrectomy enhances glucose utilization and remodels adipose tissue independent of weight loss.

Sleeve gastrectomy (SG) induces weight loss-independent improvements in glucose homeostasis by unknown mechanisms. We sought to identify the metabolic adaptations responsible for these improvements. Nonobese C57BL/6J mice on standard chow underwent SG or sham surgery. Functional testing and indirect calorimetry were used to capture metabolic phenotypes. Tissue-specific glucose uptake was assessed by 18-fluorodeoxyglucose (18-FDG) PET/computed tomography, and RNA sequencing was used for gene-expression analysis. In this model, SG induced durable improvements in glucose tolerance in the absence of changes in weight, body composition, or food intake. Indirect calorimetry revealed that SG increased the average respiratory exchange ratio toward 1.0, indicating a weight-independent, systemic shift to carbohydrate utilization. Following SG, orally administered 18-FDG preferentially localized to white adipose depots, showing tissue-specific increases in glucose utilization induced by surgery. Transcriptional analysis with RNA sequencing demonstrated that increased glucose uptake in the visceral adipose tissue was associated with upregulation in transcriptional pathways involved in energy metabolism, adipocyte maturation, and adaptive and innate immune cell chemotaxis and differentiation. SG induces a rapid, weight loss-independent shift toward glucose utilization and transcriptional remodeling of metabolic and immune pathways in visceral adipose tissue. Continued study of this early post-SG physiology may lead to a better understanding of the anti-diabetic mechanisms of bariatric surgery.

Early Changes in Immune Cell Count, Metabolism, and Function Following Sleeve Gastrectomy: A Prospective Human Study.

OBJECTIVE: To characterize longitudinal changes in blood biomarkers, leukocyte composition, and gene expression following laparoscopic sleeve gastrectomy (LSG). BACKGROUND: LSG is an effective treatment for obesity, leading to sustainable weight loss and improvements in obesity-related comorbidities and inflammatory profiles. However, the effects of LSG on immune function and metabolism remain uncertain. METHODS: Prospective data were collected from 23 enrolled human subjects from a single institution. Parameters of weight, comorbidities, and trends in blood biomarkers and leukocyte subsets were observed from preoperative baseline to 1 year postsurgery in 3-month follow-up intervals. RNA sequencing was performed on pairs of whole blood samples from the first 6 subjects of the study (baseline and 3 months postsurgery) to identify genome-wide gene expression changes associated with undergoing LSG. RESULTS: LSG led to a significant decrease in mean total body weight loss (18.1%) at 3 months and among diabetic subjects a reduction in hemoglobin A1c. Improvements in clinical inflammatory and hormonal biomarkers were demonstrated as early as 3 months after LSG. A reduction in neutrophil-lymphocyte ratio was observed, driven by a reduction in absolute neutrophil counts. Gene set enrichment analyses of differential whole blood gene expression demonstrated that after 3 months LSG induced transcriptomic changes not only in inflammatory cytokine pathways but also in several key metabolic pathways related to energy metabolism. CONCLUSIONS: LSG induces significant changes in the composition and metabolism of immune cells as early as 3 months postoperatively. Further evaluation is required of bariatric surgery's effects on immunometabolism and the consequences for host defense and metabolic disease.

Pre-operative Predictors of Weight Loss and Weight Regain Following Roux-en-Y Gastric Bypass Surgery: a Prospective Human Study.

BACKGROUND: There are currently few pre-operative predictors of initial and long-term weight loss following bariatric surgery. OBJECTIVES: We evaluated the role of pre-operative patient characteristics and baseline gut and adipose-derived hormones in predicting maximal total body weight loss (WLmax) and risk of weight regain (WR) after Roux-en-Y gastric bypass (RYGB) surgery. METHODS: One hundred five adult patients undergoing primary RYGB were prospectively recruited. Baseline demographics were recorded and fasting plasma glucose, glycosylated hemoglobin (A1C), insulin, glucagon, leptin, active ghrelin, glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) levels were measured on day of surgery. RESULTS: Our cohort had a mean age of 44.4 ± 13.0 years, and initial BMI (body mass index) of 45.1 ± 6.7 kg/m2 with mean post-operative follow-up of 40 months. Eighty patients were female and 26 had type 2 diabetes mellitus (T2D). Average WLmax was 35.3 ± 7.4%. On univariate analysis, higher baseline fasting ghrelin, lower age, lower CRP (C-reactive protein), lower A1C, and negative T2D status were associated with greater WLmax (p < 0.05). Controlling for these variables using stepwise multivariate regression, only higher fasting ghrelin and younger age were associated significantly with greater WLmax (p < 0.05). In subgroup multivariate regression analysis of T2D patients, higher ghrelin and glucagon were significantly associated with greater WLmax. Following stepwise multivariate regression, lower initial BMI and lower glucagon were associated with greater WR (p < 0.05). CONCLUSIONS: Incorporation of baseline biological and hormonal markers may help in developing more accurate predictive models for weight loss following bariatric surgery that help inform patient counseling and decision-making.

Early changes in immune cell metabolism and function are a hallmark of sleeve gastrectomy: a prospective human study.

OBJECTIVE: To characterize longitudinal changes in blood biomarkers, leukocyte composition, and gene expression following laparoscopic sleeve gastrectomy (LSG). BACKGROUND: LSG is an effective treatment for obesity, leading to sustainable weight loss and improvements in obesity-related co-morbidities and inflammatory profiles. However, the effects of LSG on immune function and metabolism remain uncertain. METHODS: Prospective data was collected from 23 enrolled human subjects from a single institution. Parameters of weight, co-morbidities, and trends in blood biomarkers and leukocyte subsets were observed from pre-operative baseline to one year in three-month follow-up intervals. RNA-sequencing was performed on pairs of whole blood samples from the first six subjects of the study (baseline and three months post-surgery) to identify genome-wide gene expression changes associated with undergoing LSG. RESULTS: LSG led to a significant decrease in mean total body weight loss (18.1%) at three months and among diabetic subjects a reduction in HbA1c. Improvements in clinical inflammatory and hormonal biomarkers were demonstrated as early as three months after LSG. A reduction in neutrophil-lymphocyte ratio was observed, driven by a reduction in absolute neutrophil counts. Gene set enrichment analyses of differential whole blood gene expression demonstrated that after three months, LSG induced transcriptomic changes not only in inflammatory cytokine pathways but also in several key metabolic pathways related to energy metabolism. CONCLUSIONS: LSG induces significant changes in the composition and metabolism of immune cells as early as three months post-operatively. Further evaluation is required of bariatric surgery's effects on immunometabolism and consequences for host defense and metabolic disease.

Short-Term Outcomes of Inflammatory Bowel Disease after Roux-en-Y Gastric Bypass vs Sleeve Gastrectomy.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are the most effective therapies for obesity and may have beneficial effects on the immune system. Therefore, we compared RYGB vs SG outcomes in patients with inflammatory bowel disease (IBD). STUDY DESIGN: In this retrospective cohort study, we identified 54 patients with either Crohn's disease (CD; n = 31) or ulcerative colitis (UC; n = 23), diagnosed before bariatric surgery, between 2000 and 2017. Nineteen patients underwent RYGB and 35 patients underwent SG. RESULTS: Patients presenting for RYGB and SG were of similar age (46.2 ± 9.5 years vs 47.2 ± 12.3 years), preoperative BMI (48.5 ± 7.7 kg/m2 vs 44.9 ± 7.3 kg/m2) and IBD status, as measured by medications. Both operations led to significant weight loss at 1 year. After RYGB and SG, there were no significant differences in the proportion of patients with UC who had improved (27% vs 8%), unchanged (64% vs 92%), or worse (9% vs 0%) IBD medication requirements, respectively. Similar analysis in the patients with CD showed no significant differences in the proportion who had improved (37.5% vs 44%), or unchanged (25% vs 52%) IBD-medication requirements after RYGB and SG, respectively. However, there was a significant difference in the proportion of patients who had worsened CD after RYGB compared with SG (37.5% vs 4%; p = 0.016). There was a greater rate of surgical complications after RYGB compared to SG (26% vs. 3%; p = 0.02). CONCLUSIONS: A sizable proportion of patients experienced improvements in IBD post-bariatric surgery. However, in CD patients, RYGB was associated with a significantly greater number of patients with increased IBD-medication requirements. Sleeve gastrectomy led to less weight loss, but had a lower rate of severe complications compared with RYGB. In patients with IBD, and particularly CD, SG may be the safer surgery.

Comparison of early type 2 diabetes improvement after gastric bypass and sleeve gastrectomy: medication cessation at discharge predicts 1-year outcomes.

BACKGROUND: Although weight loss-dependent type 2 diabetes (T2D) improvement after sleeve gastrectomy (SG) is well documented, whether SG has a weight-independent impact on T2D is less studied. OBJECTIVES: To evaluate early, weight-independent T2D improvement after SG and Roux-en-Y gastric bypass (RYGB) and its relationship to longer-term T2D outcomes. SETTING: University Hospital, United States. METHODS: We completed a retrospective cohort study of patients with T2D who underwent SG (n = 187) or RYGB (n = 246) from 2010 to 2015. Pre- and postoperative parameters, including demographic characteristics, T2D characteristics, and T2D medication requirements, blood glucose, glycosylated hemoglobin, weight, and body mass index, were reviewed. RESULTS: T2D improved within days after both SG and RYGB, with more patients off T2D medications after SG than RYGB (39% versus 25%, respectively; P < .01) at the time of discharge (2.5 ± .8 versus 2.7 ± 1 d; P = .04). Over the initial postoperative 12 months, T2D medication cessation rates remained relatively stable after SG but continued to improve after RYGB (at 12 mo: 52% versus 68%, respectively; P < .05). T2D medication cessation at discharge predicts 12-month T2D medication cessation (92% [RYGB] and 78% [SG] positive predictive value). In a mixed-effects regression model adjusting for weight loss and severity of diabetes, discharge T2D medication cessation remained a significant predictor of T2D outcomes after both RYGB (odds ratio, 51; 95% confidence interval, 16.1-161; P < .0001) and SG (6.4; 95% confidence interval, 2.8-14.7; P < .0001). CONCLUSIONS: Both SG and RYGB lead to high rates of T2D medication cessation within days of surgery, suggesting both operations activate weight loss-independent anti-T2D pathways. T2D medication cessation at discharge is predictive of 12-month T2D outcomes, particularly in noninsulin requiring patients. By 1 year after the surgery, RYGB leads to more weight loss and higher rates of T2D medication cessation than SG.

Association of Bariatric Surgery Status with Reduced HER2+ Breast Cancers: a Retrospective Cohort Study.

BACKGROUND: Bariatric surgery is associated with a reduced risk of developing certain malignancies, particularly in women. However, the impact of bariatric surgery on tumor characteristics, cancer treatment, and oncologic outcomes is unknown. METHOD: In a retrospective cohort study, 42 subjects diagnosed with breast cancer after bariatric surgery (1989-2014) were matched to 84 subjects with breast cancer (1984-2012) who did not undergo bariatric surgery, based on age, body mass index (BMI), and menopausal status at the time of breast cancer diagnosis, as well as the date of cancer diagnosis. Medical records were reviewed for cancer and bariatric endpoints. Statistical analysis was performed using mixed effects regression models, generalized estimating equation, conditional logistic regression, and Fisher's exact tests. RESULTS: Women who developed breast cancer after bariatric surgery presented at an earlier stage compared to non-operated, obese controls. In the bariatric surgery group, there were fewer tumors with human epidermal growth factor receptor 2 overexpression (HER2+) (OR 0.16 (0.03-0.76); p = 0.02), with no significant differences seen in estrogen and progesterone receptor positivity. No HER2+ cancers were found in patients who underwent Roux-en-Y gastric bypass (OR 0.00 (0.00-0.43); p = 0.002). On multivariate analysis, bariatric surgery status remained associated with reduced HER2+ breast cancers (OR 0.18 (0.03-0.99); p < 0.05). At a mean follow-up of 5 years, bariatric surgery was associated with trends toward reduced cancer-specific and all-cause mortality. CONCLUSIONS: Bariatric surgery is associated with reduced HER2+ breast cancers, suggesting that bariatric surgery can influence breast cancer characteristics and, potentially, tumor biology.

A Real-World Experience Comparison of Percutaneous and Open Femoral Exposure for Endovascular Abdominal Aortic Aneurysm Repair in a Tertiary Medical Center.

OBJECTIVE: To compare the outcomes of elective percutaneous endovascular aneurysm repair (PEVAR) versus surgical cutdown endovascular aneurysm repair (SEVAR) procedures performed at a tertiary medical center from 2012 to 2015. METHODS: This is a unique study using procedure data from two vascular surgeons who performed SEVAR in almost every case versus three vascular surgeons who performed PEVAR in all cases except when considered prohibitive on account of circumferential calcification or severe occlusive disease of the common femoral artery or some other technical consideration. Medical records of patients aged 18 years or older undergoing elective PEVAR or SEVAR between January 2012 and December 2015 were reviewed. Differences in readmissions and complications between patients who received PEVAR and those who received SEVAR were assessed using Fisher's exact test. The exact Cochran-Armitage test was used to assess trends in length of stay between the PEVAR and SEVAR group. RESULTS: A total of 183 patients were analyzed. In total, 132 underwent PEVAR and 51 underwent SEVAR. A statistically significant difference was noted with regard to 30-day readmissions (2.3% vs 13.7%, P = .006) in favor of PEVAR and categorical length of stay tended to be longer in the SEVAR group ( P = .003). The 30-day complication rate was not statistically different (6.8% vs 15.7%, P = .09). CONCLUSIONS: Surgical cutdown endovascular aneurysm repair results in more readmissions, often related to groin wound complications, which lead to prolonged length of stay and expense. Patients undergoing PEVAR tend to have a shorter length of stay. Overall complication rate was similar in the two groups. We recommend PEVAR for patients with appropriate anatomy.