Faculty Bibliography

INTRODUCTION: The relationship between the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) and its industry partners has been longstanding, productive technologically, and beneficial to patient care and education. In order to both maintain this important relationship to honor its responsibility to society for increasing transparency, SAGES established a Conflict of Interest Task Force (CITF) and charged it with identifying and managing potential conflicts of interest (COI) and limiting bias at the SAGES Annual Scientific Meetings. The CITF developed and implemented a comprehensive process for reporting, evaluating, and managing COI in accordance with (and exceeding) Accreditation Council for Continuing Medical Education guidelines. METHODS: From 2011 to 2013, all presenters, moderators, and session chairs received proactive and progressively increasing levels of education regarding the CITF rationale and processes and were required to disclose all relationships with commercial interests. Disclosures were reviewed and discussed by multiple layers of reviewers, including moderators, chairs, and CITF committee members with tiered, prescribed actions in a standardized, uniform fashion. Meeting attendees were surveyed anonymously after the annual meeting regarding perceived bias. The CITF database was then analyzed and compared to the reports of perceived bias to determine whether the implementation of this comprehensive process had been effective. RESULTS: In 2011, 68 of 484 presenters (14 %) disclosed relationships with commercial interests. In 2012, 173 of 523 presenters (33.5 %) disclosed relationships, with 49 having prior review (9.4 %), and eight required alteration. In 2013, 190 of 454 presenters disclosed relationships (41.9 %), with 93 presentations receiving prior review (20.4 %), and 20 presentations were altered. From 2008 to 2010, the perceived bias among attendees surveyed was 4.7, 6.2, and 4.4 %; and in 2011-2013, was 2.2, 1.2, and 1.5 %. CONCLUSION: It is possible to have a surgical meeting that includes participation of speakers that have industry relationships, and minimize perceived bias.

Over the past 40 years, the incidence of neuroendocrine tumors (NETs) has been increasing. Distal small bowel (i.e., midgut) NETs most often cause carcinoid syndrome manifested as cutaneous flushing, diarrhea, bronchial constriction, and cardiac involvement. Carcinoid abdominal crisis occurs when submucosal tumors impede the vascular supply to the gut leading to mesenteric ischemia and worsening abdominal pain. Here, we report the case of a young woman with progressively worsening abdominal pain. J. Surg. Oncol. 2014 110:348-351. (c) 2014 Wiley Periodicals, Inc.

BACKGROUND: Hyperinsulinemic hypoglycemia is common after Roux-en-Y gastric bypass (RYGB) and may result in weight regain. The purpose of our investigation was to compare the effect of RYGB, vertical sleeve gastrectomy (VSG), and duodenal switch (DS) on insulin and glucose response to carbohydrate challenge. METHODS: Patients meeting National Institutes of Health criteria for bariatric surgery selected their bariatric procedure after evaluation and education in this prospective nonrandomized study. Preoperatively and at 6, 9, and 12 months' follow-up, patients underwent blood draw to determine levels of fasting glucose, fasting insulin, glycated hemoglobin (HbA1c), C-peptide, and 2-h oral glucose challenge test. Homoeostatic Model Assessment (HOMA)-IR, fasting to 1-h and 1- to 2-h ratios of glucose and insulin, were calculated. Statistical analysis was performed using ANOVA and Student's paired t test. All procedures were performed via a laparoscopic technique at a single institution. RESULTS: Data from a total of 38 patients (13 RYGB, 12 VSG, 13 DS) were available for analysis. At baseline, all groups were similar; the only statistically significant difference was that DS patients had a higher preoperative weight and body mass index (BMI). All operations caused weight loss (BMI 47.7 +/- 10-30.7 +/- 6.4 kg/m2 in RYGB; 45.7 +/- 8.5-31.1 +/- 5.5 kg/m2 in VSG; 55.9 +/- 11.4-27.5 +/- 5.6 kg/m2 in DS), reduction of fasting glucose, and improved insulin sensitivity. RYGB patients had a rapid rise in glucose with an accompanying rise in 1-h insulin to a level that exceeded preoperative levels. This was followed by a rapid decrease in glucose level. In comparison, DS patients had a lower increase in glucose and 1-h insulin, and the lowest HbA1c. These differences were statistically significant at various data points. For VSG, the results were intermediary. CONCLUSIONS: Compared to gastric bypass, DS results in greater weight loss and improves insulin sensitivity and glucose homeostasis without causing a hyperinsulinemic response. Because the response to challenge after VSG is intermediary, pyloric preservation alone cannot account for this difference.

BACKGROUND: Symptoms secondary to dumping have been suggested to help patients refrain from simple carbohydrate ingestion after Roux-en-Y gastric bypass (RYGB). During follow-up examinations, we noted many patients with weight regain complaining of fatigue shortly after eating. Thus, we decided to study the glucose tolerance test (GTT) results in a cohort of post-RYGB patients. METHODS: A total of 63 RYGB patients, >6 months postoperatively, were studied with a GTT and measurement of insulin levels. The mean age was 48.5 +/- 10.8 years, mean preoperative body mass index was 49.0 +/- 6.5 kg/m(2), mean percentage of excess body mass index lost was 64.5% +/- 29.0%, mean weight regain at follow-up was 11.6 +/- 12.4 lb, and mean follow-up period was 47.9 months. RESULTS: Of the 63 patients, 49 had abnormal GTT results. Of the 63 patients, 6 were diabetic; however, only 1 of these patients had an elevated fasting glucose level. All 6 patients were diabetic preoperatively. Of the 63 patients, 43 had evidence of reactive hypoglycemia at 1-2 hours after the glucose load. Of these patients, 22 had a maximum/minimum glucose ratio >3:1, including 7 with a ratio >4:1. CONCLUSION: The results of the present study have demonstrated that an abnormal GTT result is a common finding after RYGB. Reactive hypoglycemia was found in 43 of 63 patients, with insulin values that do not support nesidioblastosis. It is our hypothesis, that rather than preventing simple carbohydrate ingestion, the induced hypoglycemia that occurs might contribute to weight regain and maladaptive eating in certain post-RYGB patients.

BACKGROUND: Our group has reported a high incidence of reactive hypoglycemia following Roux-en-Y gastric bypass (RYGB) with specific interest in postprandial insulin and the ratio of 1- to 2-h serum glucose levels. The purpose of this study is to compare the 6-month response to oral glucose challenge in patients undergoing RYGB, duodenal switch (DS), and vertical sleeve gastrectomy (VSG). METHODS: Thirty-eight patients meeting the NIH criteria for bariatric surgery who have reached the 6-month postoperative mark are the basis of this report. Preoperatively and at 6 months follow-up, patients underwent blood draw to determine levels of fasting glucose, fasting insulin, HbA1c, C peptide, and 2 h oral liquid glucose challenge test (OGTT). HOMA-IR and 1 to 2 h ratios of glucose and fasting to 1 h ratio of insulin were calculated. RESULTS: All patients underwent a successful laparoscopic bariatric procedure (VSG =13, DS =13, and RYGB = 12). All operations reduced BMI, HgbA1c, fasting glucose, and fasting insulin. HOMA IR and glucose tolerance improved with all procedures. In response to OGTT at 6 months, there was a 20-fold increase in insulin at 1 h in RYGB, which was not seen in DS. At 6 months, 1-h insulin was markedly lower in DS (p < .05), yet HbA1C was also lower in DS (p < .05). This resulted in 1- to 2-h glucose ratio of 1.9 for RYGB, 1.8 for VSG, and 1.3 for DS (p < .05). CONCLUSIONS: All operations improve insulin sensitivity and decrease HgbA1c. Six-month weight loss was substantial in all groups between 22-29% excess body weight. RYGB results in marked rise in glucose following challenge with corresponding rise in 1-h insulin. VSG has a similar response to RYGB. In comparison, at 6 months following surgery, DS causes a much lower rise in 1-h insulin, with this difference being statistically significant at p < .05. As a result, DS results in a less abrupt reduction in blood glucose. Although 1-h insulin is lower, DS patients had the lowest HbA1C at 6 months (p < .05). We believe that these findings have important implications for the choice of bariatric procedure for both diabetic and non-diabetic patients.

BACKGROUND: Symptoms of reactive hypoglycemia have been reported by patients after Roux-en-Y gastric bypass (RYGB) surgery who experience maladaptive eating behavior and weight regain. A 4-h glucose tolerance test (GTT) was used to assess the incidence and extent of hypoglycemia. METHODS: Thirty-six patients who were at least 6 months postoperative from RYGB were administered a 4-h GTT with measurement of insulin levels. Mean age was 49.4+/-11.4 years, mean preoperative body mass index (BMI) was 48.8+/-6.6 kg/m2, percent excess BMI lost (%EBL) was 62.6 +/- 21.6%, mean weight change from nadir weight was 8.2+/-8.6 kg, and mean follow-up time was 40.5+/-26.7 months. Twelve patients had diabetes preoperatively. RESULTS: Thirty-two of 36 patients (89%) had abnormal GTT. Six patients (17%) were identified as diabetic based on GTT. All six of these patients were diabetic preoperatively. Twenty-six patients (72%) had evidence of reactive hypoglycemia at 2 h post glucose load. Within this cohort of 26 patients, 14 had maximum to minimum glucose ratio (MMGR)>3:1, 5 with a ratio>4:1. Eleven patients had weight regain greater than 10% of initial weight loss (range 4.9-25.6 kg). Ten of these 11 patients (91%) with weight recidivism showed reactive hypoglycemia. CONCLUSIONS: Abnormal GTT is a common finding post RYGB. Persistence of diabetes was noted in 50% of patients with diabetes preoperatively. Amongst the nondiabetic patients, reactive hypoglycemia was found to be more common and pronounced than expected. Absence of abnormally high insulin levels does not support nesidioblastosis as an etiology of this hypoglycemia. More than 50% of patients with reactive hypoglycemia had significantly exaggerated MMGR. We believe this may be due to the nonphysiologic transit of food to the small intestine due to lack of a pyloric valve after RYGB. This reactive hypoglycemia may contribute to maladaptive eating behaviors leading to weight regain long term. Our data suggest that GTT is an important part of post-RYGB follow-up and should be incorporated into the routine postoperative screening protocol. Further studies on the impact of pylorus preservation are necessary.