Faculty Bibliography

BACKGROUND:Roux-en-Y gastric bypass (RYGB) may improve cardiometabolic risk through alteration of bile acids and L-PGDS levels. OBJECTIVE:The objective of this study was to investigate the effect of RYGB on aortic wall thickness, in relation to bile acid and L-PGDS metabolism. METHODS:Zucker diabetic fatty (ZDF) rats were divided into two groups, ad lib (n = 4), and RYGB (n = 6). Bile acid and L-PGDS were measured presurgery and fourteen weeks post-surgery. RESULTS:Elevation of bile acid levels following RYGB in Zucker Diabetic Fatty (ZDF) rodents was observed, as compared to ad lib. RYGB in ZDF rodents led to a significantly decreased aortic wall thickness (25%) as compared to ad lib control. Although bile acid metabolism is implicated in these alterations, other mediators are likely involved. Our laboratory has demonstrated lipocalin prostaglandin D2 synthase (L-PGDS) is a kno n cardiometabolic modulator that also functions as a bile acid binding protein. Therefore, L-PGDS levels were measured and a significant elevation was observed with RYGB compared to ad lib control. CONCLUSION/CONCLUSIONS:Based on these findings, RYGB showed beneficial effect on aortic wall thickness, possibly through bile acids and L-PGDS elevation in a severely obese and diabetic rodent model.

BACKGROUND:The use of opioids to achieve adequate pain relief following surgery is a common clinical practice. Opioids, however, are associated with serious adverse effects, such as respiratory depression, excessive sedation, and prolonged ileus, as well as increased mortality. The administration of intravenous (IV) acetaminophen to control postoperative pain has been effective in reducing opioid consumption in various surgical populations, but no studies have been conducted in bariatric surgery patients. This investigation was performed to determine whether IV acetaminophen reduces opioid requirements after bariatric surgery. METHODS:IV acetaminophen was added to the Winthrop-University Hospital formulary in September 2012. We conducted a retrospective chart-review analysis of bariatric surgery patients who received at least four doses of IV acetaminophen (1 g every six hours) plus opioids from October 2012 to March 2013 (after IV acetaminophen was added to the hospital formulary), compared with bariatric surgery patients who received only opioids for postoperative pain control from January 2012 to June 2012 (before IV acetaminophen was added to the hospital formulary). The study's primary endpoint was the difference between the two groups in opioid consumption, expressed in oral morphine equivalents (OMEs). Secondary endpoints included the reduction in the baseline pain score; the total amount of each opioid used; and the average hospital length of stay (LOS). RESULTS:A total of 96 patients were identified for potential enrollment from January 2012 to March 2013. Eight patients, however, did not qualify for participation because they had received only one dose of IV acetaminophen. The remaining 88 patients comprised two study groups: IV acetaminophen plus opiates (n = 44) and IV opiates alone (n = 44). Paradoxically, the patients in the acetaminophen/opiates group required significantly more opiates (in OMEs) compared with the group that received opiates alone (median, 93.5 mg versus 63.0 mg, respectively; P = 0.017). There were no significant differences between the two treatment groups in terms of the median change from baseline in pain scores (-4 versus -4; P = 0.162) or the median hospital LOS (two days versus two days; P = 0.704). CONCLUSION/CONCLUSIONS:IV acetaminophen did not reduce opioid use for postoperative pain management in bariatric surgery patients.

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/OBJECTIVE: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/METHODS: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/CONCLUSIONS: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.

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/METHODS: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/CONCLUSIONS:RYGB has beneficial cardiometabolic effects through alterations in GI hormones in a severely obese and diabetic rodent model.

BACKGROUND:Per oral endoscopic myotomy (POEM) represents a natural orifice transluminal endoscopic surgery approach to Heller myotomy. Our center was the first to offer POEM outside of Japan, allowing us to accumulate what is likely the highest single-operator POEM volume in the United States. OBJECTIVE:To define the POEM learning curve of a gastroenterologist by using a larger data set and more detailed statistical analysis than used in 2 other reports of POEM performed by surgeons. DESIGN/METHODS:Prospective cohort study. SETTING/METHODS:Tertiary-care academic medical center. PATIENTS/METHODS:We analyzed the first 93 consecutive POEMs on patients with achalasia aged >18 years without contraindications to POEM performed by a single operator from October 2009 to November 2013. INTERVENTIONS/METHODS:(1) Efficiency estimation via cumulative sum (CUSUM) analysis, (2) mastery estimation via penalized basis-spline regression and CUSUM analysis, (3) correlation of operator experience with clinical outcomes (Eckardt score improvement, lower esophageal sphincter pressure reduction) and technical errors (accidental mucosotomy rate), and (4) unadjusted and adjusted regression analysis to assess how patient characteristics affected procedure time by using a generalized linear model. MAIN OUTCOME MEASUREMENTS/METHODS:Clinical outcomes, procedure time, technical errors. RESULTS:Efficiency was attained after 40 POEMs and mastery after 60 POEMs. When we used the adjusted regression analysis, only case number (operator experience) significantly affected procedure time (P < .0001). Improvements in clinical outcomes were excellent but not significantly affected by operator experience, as was the case with accidental mucosotomies. Procedure time was not significantly affected by age, sex, achalasia stage, baseline lower esophageal sphincter pressure, baseline Eckardt score, prior treatment of achalasia, prior botulinum toxin injection, incidence of accidental mucosotomies, length of myotomy, or type of knife used (all P > .05). LIMITATIONS/CONCLUSIONS:Our analysis may underestimate the number of POEMs required to achieve mastery for operators with limited or no endoscopic submucosal dissection experience. CONCLUSION/CONCLUSIONS:These results offer thresholds for efficiency and mastery of a single gastroenterologist operator that may guide the efforts of novice POEM operators.