Faculty Bibliography

INTRODUCTION: Bariatric surgery has become a common therapeutic approach to obesity. However, bariatric procedures may affect bowel habits due to changes in dietary intake as well as altered anatomy. To date, few studies have evaluated the impact of bariatric surgery on post-operative constipation. The aim of this study is to determine if patients experience a greater rate of constipation after bariatric surgery compared to non-bariatric controls.
METHOD(S): A retrospective chart review at New York Langone Hospital (NYU) was performed on 160 bariatric surgery patients who had surgery in the year 2012 and 160 control patients with BMI < 30 kg/m2 seen in primary care in 2012. Reports of constipation were recorded up until November 2018. Exclusion criteria included those with inflammatory bowel disease or hereditary colorectal cancer syndromes prior to age 50. The primary outcome was diagnosis of post-operative constipation. Secondary outcomes included rates of constipation according to surgical procedure. Presence of constipation was recorded if listed on the problem list or if medications for constipation were prescribed. Logistic regression and chi-squared testing was used to assess differences in groups.
RESULT(S): Table 1 shows patient characteristics of the study population. The average age of bariatric surgery patients was 64.1 years compared to 69.8 in the control group. Overall, 20% of bariatric patients were diagnosed with constipation compared to 15% of controls (P = 0.239). Constipation rates post-bariatric surgery were 17.9% in lap band, 20.6% in sleeve gastrectomy, and 7.1% in gastric bypass patients (P = 0.256). A logistic regression controlling for age, sex, and Charlson co-morbidity index was performed between controls and post-surgery subjects. This revealed no significant difference in rates of constipation between the two groups (OR 1.158, 95% CI 0.790 - 1.696 P-value = 0.45). There was, however, a significant difference in constipation rates between the bariatric group pre-surgery (13.8%) and post-surgery (17.5%) (P = < 0.001) (Table 2).
CONCLUSION(S): Bariatric surgery patients experience significantly higher rates of constipation after surgery compared to prior to surgery, but similar rates to controls without obesity. Constipation impairs quality of life and is associated with significant health care costs. Further studies investigating the mechanisms underlying this increase in constipation after bariatric surgery and effective measures to treat it are warranted. (Figure Presented)

INTRODUCTION: Anastomotic gastric adenocarcinoma (GAC) following distal gastrectomy Billroth II for peptic ulcer disease (PUD) has long been recognized but remains poorly studied. CASE DESCRIPTION/METHODS: A 65-year-old male with history of PUD status post Billroth II in 1991 presented with multiple episodes of melena and abdominal pain. EGD revealed friable gastric mucosa with oozing ulcers on the gastric side of the gastrojejunal anastomosis (GJA) (Figure 1a-c) and severe bile reflux. Stomach biopsies were negative for H. pylori or other pathology. Patient was subsequently admitted four more times that year for similar symptoms, each time presenting with symptomatic anemia that resolves with therapy, and EGD showing superficial erosions near the GJA. It was suspected however, that the initial biopsies were likely taken from areas far from the actively bleeding sites. Therefore, the GI team insisted on an outpatient EGD when the patient was asymptomatic to accurately investigate the GJA. After multiple missed appointments, he had an outpatient EGD (Figure 1d) with biopsies of the friable mucosa positive for GAC, and eventually underwent Roux-en-Y gastrectomy with esophagojejunostomy. Biopsy of the mesenteric nodules confirmed the diagnosis of moderately differentiated Stage IIIA GAC. Chemoradiation therapy was initiated, but patient left against medical advice and ended up in hospice care eight months later. DISCUSSION: We present a patient with persistent bleeding ulcers and symptomatic anemia 25 years after a Billroth II procedure, who despite multiple endoscopic evaluations with stomach biopsies, was not diagnosed on time. Eventually, the correct diagnosis of Stage III primary GAC was made after an outpatient EGD with targeted biopsies of the area associated with recurrent bleeding. Given the negative biopsies, the persistent gastric ulcers were thought to be complications of Billroth II with a short limb leading to bile reflux, or due to patient's poor compliance and follow up. However, it was recognized that the patient had a higher risk of GAC as he was 15-20 years after Billroth II, and more importantly, that the inpatient EGD biopsies were not of the actively bleeding area of interest. Our patient presented after a long asymptomatic interval with symptoms initially misinterpreted as benign. It is therefore imperative to maintain a high suspicion of gastric malignancy for these patients to encourage earlier diagnosis. (Figure Presented)

Background: We previously conducted a randomized controlled trial comparing diabetes surgery to intensive medical weight management (MWM) to treat patients with type 2 diabetes (T2DM) and Body Mass Index (BMI) 30-35 kg/m². At 3 year follow-up, we found that surgery was highly effective in T2DM remission and that the soluble form of RAGE (receptor for advanced glycation end-products) may be an adequate diabetes biomarker that may help determine which patient population would benefit most from surgery. The purpose of this study is to provide longer-term (5-year) follow-up of this initial patient cohort.
Method(s): Retrospective chart review was performed of the initial patient cohort. Demographic data from the initial cohort included baseline weight, glycated hemoglobin (HbA1c) as well as medications. Repeated measures linear models were used to model weight loss and change in HBA1c.
Result(s): Originally, 57 patients with T2DM and BMI 30-35 were randomized to surgery (bypass, sleeve or band based on patient preference; n=30) vs. MWM (n=27). At baseline, mean BMI was 32.6 kg/m² and mean HbA1c was 7.8. At 5 year follow-up, the surgery group continued to have lower HbA1c (6.58 vs. 7.99) and lower BMI (27 kg/m² vs. 29.9 kg/m²) vs. the non-surgical group. At 3 years, in the surgical group, those with a higher baseline sRAGE had a lower post-op BMI.
Conclusion(s): Diabetes surgery in T2DM patients with BMI 30-35 kg/m² remains effective up to 5 years. Higher baseline sRAGE may predict success with surgery.
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Background: Portomesenteric vein thrombosis (PMVT) is a known complication after laparoscopic sleeve gastrectomy (LSG). Previous studies have indicated that many of these patients may have an undiagnosed thrombophilia. We recently changed our practice to check thrombophilia panel on every patient preoperatively undergoing LSG. The purpose of this study is to 1) estimate the prevalence of thrombophilia in patients seeking LSG and 2) determine if extended chemoprophylaxis post-LSG reduces PMVT.
Method(s): Thrombophilia panels were drawn on every patient seeking LSG after July 2018 at two high-volume bariatric surgery centers. A positive thrombophilia panel included: Factor VIII>150%, Protein C<70%, Protein S<55%, and Anti-thrombin<83%. Patients with positive thrombophilia panel were discharged on extended chemoprophylaxis. PMVT rates for all LSG performed from Jan 2014 thru July 2018 (no routine preop thrombophilia panel) were compared to PMVT rates after July thru March 2019 (routine preop thrombophilia panel).
Result(s): 1075 patients seeking LSG had thrombophilia panel checked preoperatively. The cohort was 83% female, 84% Hispanic and 15% non-Hispanic African American; mean age and BMI were 39.2 years and 43 kg/m², respectively. 577/1075 (54%) had abnormal thrombophilia panel preoperatively, including Factor VIII elevation (89.4%), Anti-thrombin III deficiency (5.9%), Protein S deficiency (2.9%), and Protein C deficiency (2.5%). Between January 2014 and July 2018, 18 PMVT were diagnosed among 4228 LSG (0.4%). After July 2018, 1 PMVT was diagnosed among 745 LSG (0.1%) who had thrombophilia panel checked preoperatively.
Conclusion(s): The estimated prevalence of thrombophilia is 54% in this patient population. Extended prophylaxis may decrease PMVT post-LSG.
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Perforated duodenal ulcer following RYGB is an unusual clinical situation that may be a diagnostic challenge. Only 23 cases have previously been reported. We present five cases. The hallmark of visceral perforation, namely pneumoperitoneum, was not seen in three of the four cases that underwent cross sectional imaging. This is perhaps due to the altered anatomy of the RYGB that excludes air from the duodenum. Our cases had more free fluid than expected. The bariatric surgeon should not wait for free intraperitoneal air to suspect duodenal perforation after RYGB.

BACKGROUND: At our medical center, female patients who have undergone bariatric surgery are advised to defer pregnancy for 2 years after surgery to avoid the following complications and their potential consequences for the fetus: inadequate gestational weight gain, inadequate postsurgical weight loss, hyperemesis gravidarum, nutritional deficiencies, gestational diabetes, and gestational hypertension. OBJECTIVES: To examine the effect of time from surgery to conception on pregnancy course and outcomes in bariatric patients. SETTING: University. METHODS: We identified 73 pregnancies in 54 women who became pregnant after undergoing bariatric surgery. Surgery to conception interval was compared between pregnancies that were carried to delivery and 8 pregnancies that resulted in spontaneous abortion. Of 41 pregnancies that were carried to delivery, 26 occurred in women who had undergone surgery less than 2 years before conception, and 15 occurred in women who had undergone surgery greater than 2 years before conception. Gestational age at delivery, number of neonatal intensive care unit admissions, gestational weight gain, hyperemesis gravidarum, nutritional deficiencies, gestational diabetes, and gestational hypertension during pregnancy were compared for the 2 groups. RESULTS: Eight patients who had spontaneous abortion had a significantly shorter time from surgery to conception. There were no significant differences between our 2 groups in rates of preterm deliveries, neonatal intensive care unit admission, gestational weight gain, hyperemesis, nutritional deficiencies, gestational diabetes, or gestational hypertension. CONCLUSIONS: Becoming pregnant within the first 2 years after bariatric surgery appears to have no effect on pregnancy course and outcomes. Women who miscarried had a significantly lower mean surgery to conception interval. These results fail to show an increased rate of pregnancy complications during the first 2 years after bariatric surgery.

BACKGROUND: Portomesenteric vein thrombosis (PMVT) has been increasingly reported after laparoscopic sleeve gastrectomy (LSG). Factor VIII (FVIII) is a plasma sialoglycoprotein that plays an essential role in hemostasis. There is increasing evidence that FVIII elevation constitutes a clinically important risk factor for venous thrombosis. OBJECTIVES: To report the prevalence of FVIII elevation as well as other clinical characteristics in a multicenter series of patients who developed PMVT after LSG. SETTING: University hospitals. METHODS: A retrospective review was conducted of all patients that developed PMVT after laparoscopic bariatric surgery from 2006 to 2016 at 6 high-volume bariatric surgery centers. RESULTS: Forty patients who developed PMVT postoperatively, all after LSG, were identified. During this timeframe, 25,569 laparoscopic bariatric surgery cases were performed, including 9749 LSG (PMVT incidence after LSG = .4%). Mean age and body mass index were 40 years (18-65) and 43.4 kg/m2 (35-59.7), respectively. Abdominal pain was the most common (98%) presenting symptom. Of patients, 92% had a hematologic abnormality identified, and of these, FVIII elevation was the most common (76%). The vast majority (90%) was successfully managed with therapeutic anticoagulation alone. A smaller number of patients required small bowel resection (n = 2) and surgical thrombectomy (n = 1). There were no mortalities. CONCLUSIONS: A high index of clinical suspicion and prompt diagnosis/treatment of PMVT usually leads to favorable outcomes. FVIII elevation was the most common (76%) hematologic abnormality identified in this patient cohort. Further studies are needed to determine the prevalence of FVIII elevation in patients seeking bariatric surgery.

Introduction: Cholangiocarcinoma and pancreatic adenocarcinoma account for over 190,000 new clinical cases of pancreatobiliary malignancy worldwide annually. For palliation of obstructive jaundice in these patients, plastic or self-expanding metal stent (SEMS) are placed. However, re-occlusion rates for currently available stents range as high as 36% for uncovered metal stents, 25% for covered metal stents and 52% for plastic stents. Tissue ingrowth accounts for up to 76% of occlusions of bare metal stents.1, 2, 3, 4 Stent occlusion can result in recurrent obstruction and typically requires endoscopic re-intervention. Therefore there is a real clinical need to reduce tissue ingrowth and improve biliary stent patency rates. Aims & Methods: In this study we developed and tested a controlled-release paclitaxel-eluting SEMS designed to prevent tissue hyperplasia and stent occlusion. A 4 cm length uncovered, laser-cut nitinol stent was coated with a polymer matrix allowing slow release of paclitaxel. Naive Yucatan swine were assigned to one of three stent groups: bare control (n=3, no polymer), standard dose paclitaxel (n=6, 149.4 mg paclitaxel) and challenge dose (n=3, 538.0 mg paclitaxel. Two stents were endoscopically implanted in each swine from its assigned group, one in the intrahepatic/hilar region and a second in the common bile duct placed proximal to the papilla. Stents were assessed for migration via digital radiographs for the first 2 weeks and then monthly via endoscopy using SpyGlassTM DS cholangioscopy and cholangiography with a targeted 6 month study endpoint. Results: At 30 days post-implant, no significant tissue reaction to any stent was observed. However, all animals displayed mild biofilm formation and increased intraductal mucus production. Substantial dilation of the common bile duct was observed in 5/11 animals with no apparent relationship between drug coating and duct dilation. At 60 days post-implant, moderate mucus and biofilm formation was observed within the stent, however in only 3 animals biliary ductal dilation persisted and the majority of stents were fully apposed to the duct wall. Although some animals displayed minimal tissue hyperplasia at the proximal end of the stents, no tissue overgrowth or stent embedding was observed in any animal. Up to 60 days post-implant, no persistent clinical symptoms were observed in any animal. Stents in one standard dose animal migrated out of the bile duct between days 15 and 30, this animal is not included in patency results reported. At both 30 and 60 day timepoints, no apparent differences in outcome were observed among the three study groups. Conclusion: At this mid-study follow-up, paclitaxel-eluting stents appear to be safe for use in naive tissue and do not negatively impact function of the biliary system, even at challenge condition doses. Although the cause of bile duct dilation observed in all stent groups has not been conclusively identified, we hypothesize the cause may be distal stent impaction and intermittent (clinically insignificant) obstruction of the papilla and/or stent, resulting in retained mucus and bile. Bile duct dilation, in turn, has reduced the opportunity for tissue overgrowth in all stent groups, which was expected to occur in the bare stent control group by 60 days post-implant5. Given the observed 60% reduction in number of dilated ducts between days 30 and 60, we expect increased rate of apposition. Ongoing efforts include continued follow-up for an additional 120 days, and in a second cohort, determination of in vivo drug release rates in the bile duct over a 30 day period. Future cholangioscopic and histopathological assessment of these swine will further clarify the safety and effectiveness of paclitaxel stent coatings to mediate bile duct tissue ingrowth

BACKGROUND: We investigated whether the surgical Apgar score (SAS) may enhance the Veterans Affairs Surgical Quality Improvement Program (VASQIP) risk assessment for prediction of early postoperative outcomes. METHODS: We retrospectively evaluated demographics, medical history, procedure, SAS, VASQIP assessment, and postoperative data for patients undergoing major/extensive intra-abdominal surgery at the Manhattan Veterans Affairs between October 2006 and September 2011. End points were overall morbidity and 30-, 60- , and 90-day mortality. Pearson's chi-square, ANOVA, and multivariate regression modeling were employed. RESULTS: Six hundred twenty-nine patients were included. Apgar groups did not differ in age, sex, and race. Low SASs were associated with worse functional status, increased postoperative morbidity, and 30-, 60- , and 90-day mortality rates. SAS did not significantly enhance VASQIP prediction of postoperative outcomes, although a trend was detected. Multivariate analysis confirmed SAS as an independent predictor of morbidity and mortality. CONCLUSIONS: SAS effectively identifies veterans at high risk for poor postoperative outcome. Additional studies are necessary to evaluate the role of SAS in enhancing VASQIP risk prediction.