Keneth Hall

Algorithmic approach to utilization of CT scans for detection of internal hernia in the gastric bypass patient

BACKGROUND While surgical exploration remains the gold standard for diagnosing internal hernia (IH) after certain bariatric surgeries, decisions for operative intervention are often based on computed tomography (CT) findings. OBJECTIVES The aim of this study is to review our institutional experience and create an algorithm to approach patients presenting with abdominal pain and/or emesis after certain bariatric procedures. SETTINGS University Hospital METHODS Following institutional review board approval, a retrospective chart review of all patients presenting with obstruction symptoms after laparoscopic Roux-en-Y gastric bypass (LRYGB) was performed at 2 institutions from 2008 to 2013. Patients without CT scans or with incidental hernia defect findings were excluded. CT and intraoperative findings were compared via univariate statistical analysis. RESULTS Fifty-two patients who underwent an operation for a suspected IH were identified. Of the 50 patients, 25 (50%) had IH at operation. Twenty-nine patients (58%) had positive CT scans read for IH and/or obstruction. Of these 29, 19 (66%) were found to have IH at operation and 10 (34%) underwent negative diagnostic laparoscopy. Of the 21 patients with negative CT scans, 6 (29%) had IH at operation versus 15 (71%) who were negative. The sensitivity of CT scan to detect an internal hernia is 76% with 95% confidence interval (CI) [53% to 90%] and specificity is 60% with 95% CI [39% to 78%]. Sensitivity increased to 96% with 95% CI [78% to 99.8%] when combining CT scans with neutrophilia findings. CONCLUSION Positive CT scans are sensitive for IH but not specific. CT scans will not detect IH in 1:4 patients; despite negative findings, surgical exploration should remain the gold standard for patients with acute abdominal pain after LRYGB or biliopancreatic diversion when IH is a consideration.

Roux-en-Y gastric bypass attenuates the progression of cardiometabolic complications in obese diabetic rats via alteration in gastrointestinal hormones

BACKGROUND Roux-en-Y gastric bypass (RYGB) ameliorates type 2 diabetes (T2DM) and obesity through alteration in gastrointestinal (GI) hormones. OBJECTIVE The objective of this study was to investigate the effect of RYGB on GI hormones and cardiometabolic parameters in Zucker diabetic fatty (ZDF) rodents. SETTING Winthrop University Hospital, Research and Academic Center METHODS Animals were divided into 3 groups, pair-fed (n = 4), ad lib (n = 4), and RYGB (n = 5). This study was carried out for 4 weeks and all related parameters were measured pre- and postsurgery in fasted obese diabetic Zucker rodents. RESULTS Postoperatively, RYGB significantly decreased fasting blood glucose by 32% compared with ad lib. Plasma insulin and leptin levels were also found to be significantly decreased, by 66% and 38%, respectively, after surgery. Moreover, both glucose-dependent insulinotropic polypeptide (GIP) and peptide tyrosine-tyrosine (PYY) were significantly increased after RYGB-by 300% and 51%, respectively. Glucagon-like peptide-1 (GLP-1) levels were also increased, but the increase was not statistically significant. Total cholesterol levels of the RYGB group remained unchanged for 4 weeks. However, total cholesterol in the ad lib and pair-fed groups increased by 25% and 34%, respectively, compared with initial levels. The cholesterol/high-density lipoprotein (HDL) ratio was decreased in the RYGB group by 14% and 30% compared with the ad lib and pair-fed group, respectively. The RYGB group had a significant decrease in aortic wall thickness of 25% compared with the ad lib and pair-fed groups. Similarly, the RYGB group had a 20-unit (mm Hg) decrease in systolic blood pressure compared with the presurgical value. CONCLUSION RYGB has beneficial cardiometabolic effects through alterations in GI hormones in a severely obese and diabetic rodent model.

Selective beneficial cardiometabolic effects of vertical sleeve gastrectomy are predominantly mediated through glucagon-like peptide (GLP-1) in Zucker diabetic fatty rats

Background Glucagon-like peptide-1 (GLP-1) level was significantly increased post Vertical Sleeve Gastrectomy (VSG), an effect believed to contribute to its beneficial cardiometabolic effects. Objective To validate the beneficial GLP-1 mediated cardiometabolic effects post VSG using GLP-1 antagonist (exendin 9-39) in Zucker diabetic fatty rats. Methods Animals were divided into three (n = 5) groups: (i) sham, (ii) VSG, and (iii) VSG received exendin 9–39 (GLP-1 receptor antagonist). The study was performed over 12 weeks and parameters were measured 12 weeks post-surgery. Results and discussion As expected, fasting blood glucose and insulin levels were improved post VSG due to enhanced GLP-1 secretion. However, both fasting glucose and insulin levels were impaired in the presence of GLP-1 antagonist. Baseline total cholesterol level pre-surgery was 100±1 mg/dl which remained unchanged in the VSG group but significantly increased to 140±8 mg/dl in the presence of antagonist. Interestingly, post-surgery there was a nearly 70% reduction in triglyceride level in the VSG group compared to sham which was overcome in the presence of antagonist. Myographic studies using aortic rings showed no significant change between groups. Additionally, blood pressure and heart rate also remained unchanged in all groups. Serum bile acid and L-PGDS levels increased post VSG but significantly decreased in the presence of antagonist, suggesting a strong association with GLP-1 and a novel mechanism of action. Conclusion Enhanced GLP-1 secretion post VSG imparted beneficial cardiometabolic effects on blood glucose, insulin, total cholesterol, triglyceride, bile acids and L-PGDS levels which were abated in the presence of GLP-1 antagonist.

Mo1890 Elevation of Bile Acids After Bariatric Surgery May Attenuate Early Atherosclerosis

Introduction: Colorectal cancers (CRC) express Angiogenin (ANG), Galectin-3 (Gal-3) and Activin A (Act-A). The binding of ANG to actin on endothelial cell promote EC migration and angiogenesis. Cellular Gal-3 levels associated with cancer cell invasion, angiogenesis and tumor progression. Act-A act via binding to trans membrane receptors and support cancer cell migration. Blood levels of ANG, Gal-3 and Act-A in colorectal cancer (CRC) have not been well studied. This studys purpose was to measure preoperative (PreOp) plasma ANG, Gal-3 and Act-A levels in CRC and benign pathology (BP) patients (pts.) and to assess the diagnostic efficacy of these proteins alone and together. Method: CRC or BP pts having bowel resection for whom PreOp plasma was available (from IRB approved tissue bank) were studied. Plasma ANG (ng/ml), Gal-3 and Act-A (pg/ml) levels were analyzed in duplicate via ELISA (results: median + 95%CI). Intergroup levels were compared by the Mann-Whitney test (significant;p <0.05). The plasma receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) were used to evaluate single and combined proteins levels. Results: Plasma from 43 BP (polyp 28%, diverticulitis 56%, other 16%) and 120 CRC (83% colon, 17% rectal) pts. were studied. The CRC stage distribution was: Stage1, 25%; Stage-2, 37%, Stage-3, 26%, Stage4, 12%. Median PreOp proteins levels in CRC pts. were significantly higher than BP levels.[ ANG; 390.9,CI: 373.2,405.5 vs 316.8,CI: 297.5,350.9; Gal-3; 12.0,CI: 10.6,13.8 vs 8.9,CI: 7.2,11.1; Act-A; 369.7 CI:349.2,424.0 vs 277.9 CI: 209.3,346.7;P<0.001). Plasma Act-A levels were significantly higher in the Stage 4 pts. than in the stage 1 group ( p=0.001). The single AUC values from the ROC curve for ANG, Gal-3 and Act-A were 0.719, 0.709 and 0.741 with associated 81%, 47% and 42%. The 3 protein combination improved the AUC (0.856) and specificity (90.7%). Conclusion: CRC median ANG, Gal-3 and Act-A levels were significantly higher (23%, 35% & 33% respectively) than BP levels. Although not proven, we believe the plasma elevations are due to the tumor. Higher levels of ANG, Gal-3 and Act-A in plasma of CRC pts. may be related to the tumor cells, stromal cells, and inflammatory cells surrounding the cancer; these elevated levels may related to neovascularization and inflammation-induced tissue remodeling at tumor sites. The 3 protein combination had improved AUC & specificity vs single protein results and may have value as a diagnostic panel. A larger study is needed.