Faculty Bibliography

BACKGROUND: Thirty-day readmission post-bariatric surgery is used as a metric for surgical quality and patient care. We sought to examine factors driving 30-day readmissions after laparoscopic sleeve gastrectomy (LSG). METHODS: We reviewed 1257 LSG performed between March 2012 and June 2014. Readmitted and nonreadmitted patients were compared in their demographics, medical histories, and index hospitalizations. Multivariable regression was used to identify risk factors for readmission. RESULTS: Forty-five (3.6 %) patients required 30-day readmissions. Forty-seven percent were readmitted with malaise (emesis, dehydration, abdominal pain) and 42 % with technical complications (leak, bleed, mesenteric vein thrombosis). Factors independently associated with 30-day readmission include index admission length of stay (LOS) >/=3 days (OR 2.54, CI = [1.19, 5.40]), intraoperative drain placement (OR 3.11, CI = [1.58, 6.13]), postoperative complications (OR 8.21, CI = [2.33, 28.97]), and pain at discharge (OR 8.49, CI = [2.37, 30.44]). Patients requiring 30-day readmissions were 72 times more likely to have additional readmissions by 6 months (OR 72.4, CI = [15.8, 330.5]). CONCLUSIONS: The 30-day readmission rate after LSG is 3.6 %, with near equal contributions from malaise and technical complications. LOS, postoperative complications, drain placement, and pain score can aid in identifying patients at increased risk for 30-day readmissions. Patients should be educated on postoperative hydration and pain management, so readmissions can be limited to technical complications requiring acute inpatient management.

RATIONALE: Obesity is characterized by increased systemic and pulmonary blood volumes (pulmonary vascular congestion). Concomitant abnormal alveolar membrane diffusion suggests subclinical interstitial edema. In this setting, functional abnormalities should encompass the entire distal lung including the airways. OBJECTIVES: We hypothesize that in obesity: 1) pulmonary vascular congestion will affect the distal lung unit with concordant alveolar membrane and distal airway abnormalities; and 2) the degree of pulmonary congestion and membrane dysfunction will relate to the cardiac response. METHODS: 54 non-smoking obese subjects underwent spirometry, impulse oscillometry (IOS), diffusion capacity (DLCO) with partition into membrane diffusion (DM) and capillary blood volume (VC), and cardiac MRI (n = 24). Alveolar-capillary membrane efficiency was assessed by calculation of DM/VC. MEASUREMENTS AND MAIN RESULTS: Mean age was 45+/-12 years; mean BMI was 44.8+/-7 kg/m2. Vital capacity was 88+/-13% predicted with reduction in functional residual capacity (58+/-12% predicted). Despite normal DLCO (98+/-18% predicted), VC was elevated (135+/-31% predicted) while DM averaged 94+/-22% predicted. DM/VC varied from 0.4 to 1.4 with high values reflecting recruitment of alveolar membrane and low values indicating alveolar membrane dysfunction. The most abnormal IOS (R5 and X5) occurred in subjects with lowest DM/VC (r2 = 0.31, p<0.001; r2 = 0.34, p<0.001). Cardiac output and index (cardiac output / body surface area) were directly related to DM/VC (r2 = 0.41, p<0.001; r2 = 0.19, p = 0.03). Subjects with lower DM/VC demonstrated a cardiac output that remained in the normal range despite presence of obesity. CONCLUSIONS: Global dysfunction of the distal lung (alveolar membrane and distal airway) is associated with pulmonary vascular congestion and failure to achieve the high output state of obesity. Pulmonary vascular congestion and consequent fluid transudation and/or alterations in the structure of the alveolar capillary membrane may be considered often unrecognized causes of airway dysfunction in obesity.

Introduction: Laparoscopic sleeve gastrectomy (LSG) is currently the most common bariatric surgical procedure in the US. It is considered technically simpler to perform than the gastric bypass and is more effective than the gastric band. It is an ideal procedure to implement in an urban safety-net hospital with limited resources. There is also debate regarding "Center of Excellence (COE)" accreditation and potential decreased access to bariatric surgery for under-represented minorities. Methods: A retrospective chart review of the first 1000 LSG at our institution was performed. Our institution is a public hospital that primarily serves under-represented minorities. Patient demographics and surgical outcomes were collected. A repeated measures model was used to create a % excess weight loss (%EWL) model. Outcomes were also compared before vs. after COE accreditation. Results: The cohort was predominantly Hispanic and non-Hispanic African American (96%). The vast majority (>75%) were insured publicly or were uninsured (15%). Mean age and BMI were 39 years and 45 kg/m2, respectively. There was an eleven-fold increase in surgical volume after COE accreditation. 1 year %EWL was 64%. 30-day readmission and reoperation was 1.5% and 0.4%, respectively. Leak rate was 1.2%. There were no mortalities. Conclusions: The COE model facilitated safe expansion of LSG at an urban safety-net institution

Intro: Laparoscopic adjustable gastric banding is well-known for its safety profile. However, band removal, especially for a device-related complication, may be more complex due to the scar tissue created by the band. The objective of this study is to review perioperative outcomes of patients requiring band removal for device-related complications. Methods: A retrospective review was conducted of all band removals over a 13 year period (2001-2014) for a device-related complication (e.g. slippage, erosion, gastric necrosis). Bands removed for weight loss failure or intolerance were excluded from this review. Perioperative complication, readmission and reoperation/re-intervention was defined according to the Metabolicand Bariatric Surgery Accreditation and Quality Improvement Program standards. Results: A total of 104 patients required band removal for a device-related complication. In the same time frame 7633 bands were implanted. The average age at band removal was 44 years old and the average BMI was 35.6. The most common reason was slip (42%) and erosion (28%). The 30-day complication rate from the removal was 26% (27/104) - most commonly pneumonia and perigastric abscess. The 30-day readmission rate and reoperation/ re-intervention rate were 15% and 10%, respectively. There was one mortality (1%) from septic shock secondary to erosion. There were no statistically significant differences in age (p = 0.452) or BMI (p = 0.523) between those who had a 30-daycomplication and those who did not. Conclusions: Band-related complications are rare. Band removal for device-related complication may be associated with significant morbidity

Background: At our medical center, female patients who have undergone bariatric surgery are advised to defer pregnancy for two years surgery, in an attempt to avoid the following complications: inadequate maternal weight gain (for pregnancy), inadequate maternal weight loss (following bariatric surgery), hyperemesis gravidarum, and nutritional deficiencies. Methods: We examined our database of bariatric surgery patients from a large, urban, public hospital from March 2011 to July 2013. During that period, we identified 54 women who became pregnant after undergoing bariatric surgery. Of these women, 41 were included in the analysis. Twenty-six pregnancies occurred in women who had undergone bariatric surgery less than 2 years prior to conception, and 15 occurred in women who had undergone bariatric surgery greater than 2 years prior to conception. Gestational age at delivery, number of NICU admissions, weight gain during pregnancy, hyperemesis gravidarum, and nutritional deficiencies (iron, vitamins, protein, glucose) during pregnancy were compared for the two groups. Results: The women with <2 years between bariatric surgery and conception had a higher percentage of RYGB and LSG surgeries (p=0.0003), and had more weight loss (p=0.018) and BMI loss (0.014) from bariatric surgery to conception. There were no significant differences in pregnancy outcomes when comparing mothers with <2 years and >2 years between bariatric surgery and conception. The rates of full-term deliveries (85% vs. 87%, P=0.321), NICU admissions (4% vs. 7%, P=0.999), hyperemesis gravidarum (31% s. 40%, P=0.548) were not significantly different between the two groups. There were also no significant differences in nutritional deficiences, including iron (58% vs. 60%, P=0.885), vitamin B1(46% vs. 20%, P=0.177), vitamin B6 (12% vs. 0%, P=0.287), vitamin B12 (31% vs. 13%, P=0.277) vitamin D (65% vs. 87%, P=0.168), protein (62% vs. 40%, P=0.183) and low blood glucose (77% vs. 73%, P=0.999). Conclusions: There were no significant differences in gestational age, rate of NICU admission, pregnancy weight gain, hyperemesis, or nutritional deficiencies when comparing women who conceived within 2 years or after 2 years of their bariatric surgery. (Table Presented)

Introduction: To provide longer-term follow-up of a previously published pilot randomized trial comparing bariatric surgery vs. intensive medical weight management (MWM) in patients with type 2 diabetes (T2DM) and BMI 30-35. Additionally, to assess whether the soluble form of RAGE (receptor for advanced glycation end-products) is an adequate diabetes biomarker that may help determine which patient population would benefit most from surgery. Methods: Originally, 57 patients with T2DM and BMI 30-35 were randomized to surgery (bypass, sleeve or band, based on patient preference; n=29) vs. MWM (n=28). The 6 month results showed that surgery was significantly effective (previously published data). We performed an updated review of this patient cohort to evaluate weight loss and diabetes remission at 2 years. A repeated measures linear model was created to compare the change in HbA1C and BMI between the two groups. The outcomes were also compared to baseline sRAGE status using a repeated measures linear model. Patients who ultimately crossed over from MWM to surgery group (after the initial study) were included. Results: At baseline, mean BMI was 32.6 and mean HbA1c was 7.8. At 2 years the following was noted: The surgery group continued to have significantly higher diabetes remission (50% vs. 0%), lower BMI (28.5 vs. 30.9; p<0.0001) and lower HbA1c (7.0 vs. 7.9; p=0.019) than the MWM group. In the surgical group, those with a higher baseline sRAGE had a lower post-op BMI (p=0.037). Conclusion: At 2 years, bariatric surgery was very effective in patients with T2DM and BMI 30-35. Higher baseline sRAGE predicted success with surgery. However, larger studies will be required to confirm the accuracy of these observations

Background: Mesenteric venous thrombosis (MVT) is a rare and potentially lethal complication of laparoscopic bariatric surgery. We present the diagnosis, management and surveillance of three MVT cases after laparoscopic sleeve gastrectomy (LSG). Methods: Three morbidly obese (BMIs 40kg/m²-52kg/m²) women between the ages 33-50 years presented with symptoms of abdominal pain after uncomplicated LSG. Symptoms presented between postoperative day 12 and 25. All patients underwent computed tomography (CT) scans and were found to have mesenteric vein thrombosis. Treatment modalities varied between warfarin anticoagulation in two patients and rivaroxaban in the third, who was resistant to heparin. One patient was positive for the prothrombin gene mutation, but hypercoagulability workup was negative for the other two patients. Results: Repeat imaging was available for two patients at 4 and 18 months postoperatively. At 4 months, one patient developed cavernous transformation of the portal vein and upper abdominal varices. Repeat imaging in another patient demonstrated chronic SMV thrombosis at 18 months. Conclusions: MVT can present with nonspecific abdominal symptoms after LSG. The mainstay of treatment is anticoagulation, but the duration, especially for chronic MVT, is unclear. On surveillance, two patients have chronic MVT despite anticoagulation and negative hematologic workup, which can lead to portal hypertension and its sequelae. Additional research is needed to define the incidence, symptomatology, and treatment algorithms for this rare but serious complication

Introduction: Staple line leak is the most feared complication after sleeve gastrectomy. Intraoperative methylene blue and air leak tests are routinely used to evaluate for leak, however the utility of these tests is controversial. The 2012 International Sleeve Gastrectomy Expert Panel failed to reach a consensus about whether routine intraoperative leak tests should be performed. Additionally, these tests are not benign - they introduce increased instrumentation, with reports of nasogastric tubes causing esophageal perforation, as well as increased costs in the form of resource utilization. We hypothesize that the practice of routine intraoperative leak testing is unnecessary during sleeve gastrectomy. Methods and Procedures: A retrospective cohort study was designed using a prospectively-collected database of seven bariatric surgeons from two institutions. 1,257 consecutive patients who underwent sleeve gastrectomies between March 2012 and June 2014 were included. The performance of intraoperative leak testing and the type of test (air or methylene blue) were based on surgeon preference. Data obtained included BMI, patient demographics, comorbidity, presence or absence of intraoperative leak test, result of leak test, and type of test. The primary outcome was leak rate between the leak test (LT) group and the non-leak test (NLT) group. SPSS-22 was used for univariate and multivariate analyses. Results: Of the 1,257 sleeve gastrectomy cases, most (99.68 %) were laparoscopic, except for two (0.16 %) open and two (0.16 %) converted cases. 1,164 (92.6 %) patients had routine intraoperative leak tests performed; there were no positive intraoperative leak tests in the entire cohort. 93 patients (7.4 %) did not have intraoperative leak tests performed. Thirteen (1 %) patients developed staple line leaks, with no difference in leak rate between the LT and NLT groups (1 % vs. 1.1 %, p = 1.000). There were some baseline differences between the groups, however (Table 1). After adjusting for these differences and other possible confounders with binary logistic regression, the observed lack of association between leak and intraoperative leak test remained. In this cohort, leaks presented at a mean of 11.3 days postoperatively (range = [1,35]), with only two leaks presenting during the index admission. Of those two, one patient with a leak seen on postoperative day 1 esophagram underwent a repeat leak test during diagnostic laparoscopy, which was negative. Despite suture reinforcement, the leak persisted and the patient eventually required conversion to gastric bypass. Conclusion: Intraoperative leak testing has no correlation with postoperative leak occurrence after laparoscopic sleeve gastrectomy and is not predictive of the later development of staple line leak. (Table Presented)