Faculty Bibliography

BACKGROUND: Leak after laparoscopic sleeve gastrectomy (LSG) often presents after hospital discharge, making timely diagnosis difficult. This study evaluates the utility of radiological upper gastrointestinal (UGI) series and clinical indicators in detecting leak after LSG. METHODS: A retrospective case-controlled study of 1762 patients who underwent LSG from 2006 to 2014 was performed. All patients with radiographically confirmed leaks were included. Controls consisted of patients who underwent LSG without leak, selected using a 10:1 case-match. Data included baseline patient characteristics, surgical characteristics, and UGI series results. Clinical indicators including vital signs, SIRS criteria, and pain score were compared between patients who developed leak and controls. RESULTS: Of 1762 LSG operations, 20 (1.1 %) patients developed leaks and were compared with 200 case-matched controls. Three patients developed leak during their index admission [mean = 1.3 days, range (1, 2)], while the majority (n = 17) were discharged and developed symptoms at a mean of 17.1 days [range (4, 63)] postoperatively. Patients diagnosed with leak were similar to controls in baseline and surgical characteristics. Contrast extravasation on routine postoperative UGI identified two patients with early leaks, but was negative in the remainder (89 %). Patients with both early and delayed leaks demonstrated significant clinical abnormalities at the time of leak presentation, prior to confirmatory radiographic study. In multiple regression analysis, independent clinical factors associated with leak included fever [OR 16.6, 95 % CI (4.04, 68.10), p < 0.0001], SIRS criteria [OR 7.0, 95 % CI (1.47, 33.26), p = 0.014], and pain score >/=9 [OR 19.1, 95 % CI (1.38, 263.87), p = 0.028]. CONCLUSIONS: Contrast extravasation on routine postoperative radiological UGI series may detect early leaks after LSG, but the vast majority of leaks demonstrate normal results and present 2-3 weeks after discharge. Therefore, clinical indicators (specifically fever, SIRS criteria, and pain score) are the most useful factors to raise concern for leaks prior to confirmatory radiographic study and may be used as criteria to selectively obtain UGI studies after LSG.

Aims: Leaks after laparoscopic sleeve gastrectomy (LSG) often present after discharge from the hospital, making it difficult to diagnose leak in the early postoperative period. This study evaluates preoperative, intraoperative, and postoperative factors in their association with leaks after LSG. Methods: A retrospective case-controlled study of 1762 LSG from 2006-2014 was performed. All radiographically confirmed leaks were included. Controls were patients who underwent LSG without leak, selected using a 10:1 (control:study) case-match. Data included patient characteristics, intraoperative factors, and esophagram results. Clinical indicators including SIRS criteria (presence of = 2: temperature<36 degreeC or >38 degreeC, heart rate>90 bpm, respiratory rate>20 breaths/min,WBC>12,000 or <4,000) and self-reported pain score were collected on postoperative day (POD) 2 and at the time of leak, if applicable. Statistics included univariate analyses and multivariate logistic regression. Results: Of the 1762 LSG, 20 (1.1 %) leaks were compared with 200 case-matched controls. Three patients developed leak during their index admission (mean = 1.3 days, range = [1,2]), while the majority (n = 17) were discharged and developed symptoms at a mean of 17.1 days (median = 15, range = [4,63]) postoperatively. Leaks were similar to controls in baseline characteristics; however, the leak group had fewer black patients (5 % vs. 17 %, p = 0.022). There were no differences in intraoperative characteristics including staple reinforcement, bougie size, leak test, or operativetime between groups. Contrast extravasation on routine postoperative esophagram was seen in only two (10 %) of the twenty patients with enteric leaks; other esophagram findings (e.g. delay, dilatation) did not differ between leaks and controls. Patients with both early and late leaks demonstrated significant clinical abnormalities at the time of leak presentation, prior to confirmatory radiographic study. In multiple regression analysis, independent factors associated with leak included fever (p<0.0001), SIRS criteria (p = 0.0034), and pain score = 9 (p = 0.010). Conclusions: Contrast extravasation on routine postoperative esophagram may detect early leaks after LSG, but the vast majority of leaks have normal results and present days to weeks after discharge. Therefore, clinical indicators (specifically fever, SIRS criteria, and pain score) are the most useful factors to raise concern for leaks prior to confirmatory radiographic study, and may be used as criteria to selectively obtain postoperative esophagrams after LSG

BACKGROUND: Staple line leak is a serious complication of sleeve gastrectomy. Intraoperative methylene blue and air leak tests are routinely used to evaluate for leak; however, the utility of these tests is controversial. We hypothesize that the practice of routine intraoperative leak testing is unnecessary during sleeve gastrectomy. METHODS: A retrospective cohort study was designed using a prospectively collected database of seven bariatric surgeons from two institutions. All patients who underwent sleeve gastrectomy from March 2012 to November 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, demographics, comorbidity, presence of intraoperative leak test, result of test, and type of test. The primary outcome was leak rate between the leak test (LT) and no leak test (NLT) groups. SAS version 9.4 was used for univariate and multivariate analyses. RESULTS: A total of 1550 sleeve gastrectomies were included; most were laparoscopic (99.8 %), except for one converted and two open cases. Routine intraoperative leak tests were performed in 1329 (85.7 %) cases, while 221 (14.3 %) did not have LTs. Of the 1329 cases with LTs, there were no positive intraoperative results. Fifteen (1 %) patients developed leaks, with no difference in leak rate between the LT and NLT groups (1 vs. 1 %, p = 0.999). After adjusting for baseline differences between the groups with a propensity analysis, the observed lack of association between leak and intraoperative leak test remained. In this cohort, leaks presented at a mean of 17.3 days postoperatively (range 1-67 days). Two patients with staple line leaks underwent repeat intraoperative leak testing at leak presentation, and the tests remained negative. CONCLUSION: Intraoperative leak testing has no correlation with leak due to laparoscopic sleeve gastrectomy and is not predictive of the later development of staple line leak.

BACKGROUND: Many insurance companies require a medical weight management (MWM) program as a prerequisite for approval for bariatric surgery. There is debate regarding the benefit of this requirement. The objective of this study is to assess the effect of insurance-mandated MWM programs on weight loss outcomes in our bariatric surgery population. OBJECTIVE: To assess the effect of insurance-mandated MWM programs on weight loss outcomes in our bariatric surgery population. SETTING: University. METHODS: A retrospective review of all bariatric surgery cases performed between 2009 and 2013 was conducted. Patients were stratified by payor mix based on whether the insurance company required MWM. To control for differences between groups, a bucket matching algorithm was used to match patients based on gender, age, body mass index (BMI), and surgery type (sleeve gastrectomy, gastric bypass, or gastric band). A repeated-measures regression model was created to estimate percent excess weight loss, percent excess BMI loss, and percent total weight loss. RESULTS: A total of 1432 bariatric surgery patients were reviewed. The bucket-matching algorithm resulted in 560 patients for final analysis. Mean age and BMI were 41 years and 43 kg/m2, respectively, and 91% were female. The regression model found no significant differences in weight loss outcomes between the MWM group and the comparison group at 1 year and 2 years-percent total weight loss: 21.3% [95% confidence interval [CI] 20.6%-22.1%] versus 20.2% [95%CI 19.7%-20.6%) at 1 year and 23.4% [95%CI 22.6%-24.3%] versus 21.5% [95%CI 21.0%-22.0%] at 2 years. CONCLUSION: There was no difference in weight loss outcomes up to 2 years in patients who required insurance-mandated MWM programs. Longer-term studies are needed to determine the benefit of this insurance requirement.

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.

OBJECTIVE: This study examined whether changes in adipocyte long chain fatty acid (LCFA) uptake kinetics explain the weight regain increasingly observed following bariatric surgery. METHODS: Three groups (10 patients each) were studied: patients without obesity (NO: BMI 24.2 +/- 2.3 kg m(-2) ); patients with obesity (O: BMI 49.8 +/- 11.9); and patients classified as super-obese (SO: BMI 62.6 +/- 2.8). NO patients underwent omental and subcutaneous fat biopsies during clinically indicated abdominal surgeries; O were biopsied during bariatric surgery, and SO during both a sleeve gastrectomy and at another bariatric operation 16 +/- 2 months later, after losing 113 +/- 13 lbs. Adipocyte sizes and [(3) H]-LCFA uptake kinetics were determined in all biopsies. RESULTS: Vmax for facilitated LCFA uptake by omental adipocytes increased exponentially from 5.1 +/- 0.95 to 21.3 +/- 3.20 to 68.7 +/- 9.45 pmol/sec/50,000 cells in NO, O, and SO patients, respectively, correlating with BMI (r = 0.99, P < 0.001). Subcutaneous results were virtually identical. By the second operation, the mean BMI (SO patients) fell significantly (P < 0.01) to 44.4 +/- 2.4 kg m(-2) , similar to the O group. However, Vmax (40.6 +/- 11.5) in this weight-reduced group remained ~2X that predicted from the BMI:Vmax regression among NO, O, and SO patients. CONCLUSIONS: Facilitated adipocyte LCFA uptake remains significantly upregulated >/=1 year after bariatric surgery, possibly contributing to weight regain.

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)

OBJECTIVE: To compare bariatric surgery versus intensive medical weight management (MWM) in patients with type 2 diabetes mellitus (T2DM) who do not meet current National Institutes of Health criteria for bariatric surgery and to assess whether the soluble form of receptor for advanced glycation end products (sRAGE) is a biomarker to identify patients most likely to benefit from surgery. BACKGROUND: There are few studies comparing surgery to MWM for patients with T2DM and BMI less than 35. METHODS: Fifty-seven patients with T2DM and BMI 30 to 35, who otherwise met the criteria for bariatric surgery were randomized to MWM versus surgery (bypass, sleeve or band, based on patient preference). The primary outcomes assessed at 6 months were change in homeostatic model of insulin resistance (HOMA-IR) and diabetes remission. Secondary outcomes included changes in HbA1c, weight, and sRAGE. RESULTS: The surgery group had improved HOMA-IR (-4.6 vs +1.6; P = 0.0004) and higher diabetes remission (65% vs 0%, P < 0.0001) than the MWM group at 6 months. Compared to MWM, the surgery group had lower HbA1c (6.2 vs 7.8, P = 0.002), lower fasting glucose (99.5 vs 157; P = 0.0068), and fewer T2DM medication requirements (20% vs 88%; P < 0.0001) at 6 months. The surgery group lost more weight (7. vs 1.0 BMI decrease, P < 0.0001). Higher baseline sRAGE was associated with better weight loss outcomes (r = -0.641; P = 0.046). There were no mortalities. CONCLUSIONS: Surgery was very effective short-term in patients with T2DM and BMI 30 to 35. Baseline sRAGE may predict patients most likely to benefit from surgery. These findings need to be confirmed with larger studies.ClinicalTrials.gov ID: NCT01423877.

OBJECTIVE:: To conduct a systematic review to identify surgical strategies that may decrease leak after laparoscopic sleeve gastrectomy (LSG). BACKGROUND:: LSG is growing in popularity as a primary bariatric procedure. Technical aspects of LSG including bougie size remain controversial. METHODS:: Our systematic review yielded 112 studies encompassing 9991 LSG patients. A general estimating equation (GEE) model was used to calculate the odds ratio (OR) for leak based on bougie size, distance from the pylorus, and use of buttressing on the staple line. Baseline characteristics, including age and body mass index (BMI), were included. A linear repeated measures regression model compared excess weight loss (%EWL) between bougie sizes. RESULTS:: A total of 198 leaks in 8922 patients (2.2%) were identified. The GEE model revealed that the risk of leak decreased with bougie >/=40 Fr (OR = 0.53, 95% CI = [0.37-0.77]; P = 0.0009). Buttressing did not impact leak. There was no difference in %EWL between bougie <40 Fr and bougie >/=40 Fr up to 36 months (mean: 70.1% EWL; P = 0.273). Distance from the pylorus did not affect leak or %EWL. CONCLUSIONS:: Utilizing bougie >/=40 Fr may decrease leak without impacting %EWL up to 3 years. Distance from the pylorus does not impact leak or weight loss. Buttressing does not seem to impact leak; however, if surgeons desire to buttress, bioabsorbable material is the most common type used. Longer-term studies are needed to definitively determine the effect of bougie size on weight loss after LSG.