Faculty Bibliography

Background: The purpose of this study was to objectively assess the resolution of obesity-related comorbidities (ORC) after bariatric surgery and to compare the status and resolution of comorbidities following laparoscopic adjustable gastric banding (LAGB), roux-en-Y gastric bypass (RYGB), and sleeve gastrectomy (LSG). Methods: Data was collected from an IRB-approved electronic registry, including patient demographics, weight, BMI, and ORC status. Using the registry, ten ORCs were scored, pre-op and post-op, from 0-5 according to severity using the Assessment of Obesity-Related Comorbidities (AORC) Scale, the basis for the Bariatric Outcomes Longitudinal Database. The ten ORCs were: osteoarthritis (OA), diabetes, hypertension (HTN), obstructive sleep apnea, hyperlipidemia (HLD), gastroesophageal reflux disease, depression, urinary stress incontinence, hernia, and lower extremity edema (LEE). Resolution of disease was defined as having AORC>0 pre-surgery and AORC=0 post-surgery. Change in ORC status was calculated with the following equation: (pre-op AORC score) - (post-op AORC score). Paired t-tests were utilized to determine whether comorbidity change was significant following bariatric surgery. Fisher's exact tests were used to determine if there was a significant difference in ORC resolution between procedures. Results: 264 patients with ORC underwent bariatric surgery between January 2008 and March 2010 at an urban safety-net hospital. Average pre-op age was 42.5, and average pre-op BMI was 44.2. At mean patient follow-up of 17.2 months, the %EWL of RYGB, LSG and LAGB was 43.6%, 37.4% EWL, and 23.3% EWL, respectively (p < .0001). Resolution of 4 comorbidities (OA, HTN, HLD, and LEE) was found to be significantly different between surgery types (p<0.05): The percentage of patients with OA resolution was 71% for RYGB, 63% for LSG, and 51% for LAGB. HTN resolution was 57% for RYGB, 23% for LAGB, and 29% for LSG. HLD resolution was 71% for LSG, 67% for RYGB, and 34% for LAGB. LEE resolution was 100% for LSG (n=6), 94% for RYGB, and 68% for LAGB. RYGB produced an overall mean ORC resolution of 66%, vs 60% and 44% produced by LSG and LAGB, respectively. All bariatric surgery procedures had statistically significant AORC score change for all 10 documented comorbidities (p < .0001). The overall mean change in AORC score for all comorbidities, from pre-op to post-op, was 1.7 for RYGB patients, 1.4 for LSG patients, and 1.2 for LAGB patients. There was no significant association between initial BMI and change in AORC score. The pre-op AORC scores were not significantly different between surgery types. Conclusions: RYGB had the greatest ORC resolution for patients with OA and HTN, as well as the greatest mean ORC status improvement overall. LSG produced the greatest significant ORC resolution for patients with HLD and LEE. RYGB, LSG, and LAGB had statistically significant ORC status improvement for all 10 documented comorbidities

Introduction: We aimed to determine the effects of body mass index (BMI) on outcomes after liver resection performed at the Veteran Administration. Methods: We queried the VASQIP database for liver resections (2005-2008), and grouped the patients into fi ve categories: normal weight (NW, BMI 18.5-24.9), overweight (OW, BMI 25-29.9) Class 1 (OB1, BMI 30-34.9), Class 2 (OB2, BMI 35-39.9), and Class 3 obesity (OB3, BMI >= 40). Differences in risk factors and perioperative complications across groups were analyzed. Results: Of 403 patients who underwent hepatectomy, 106 (26.3%) were NW, 161 (40.0%) OW, 94 (23.3%) OB1, 31 (7.7%) OB2, and 11 (2.7%) OB3. The BMI groups were similar in patient gender, age, diagnosis (90.3% malignancy), ASA class, rates of alcohol abuse, ascites, esophageal varices, and neoadjuvant treatment. Higher BMI was associated with increased rates of diabetes (18% vs. 27% vs. 36% vs. 39% vs. 45%, p 0.04) and lower incidence of smokers (53% vs. 35% vs. 30% vs. 16% vs. 9%, p 0.0001). There were no differences in type of resection performed, operative time, work RVU. OB3 received more blood transfusions (OB3 4.3 +/- 2.7 vs. NW 1.1 +/- 0.2, p 0.02). There were no differences across BMI groups in overall and specifi c morbidity, as well in length of stay. Nevertheless, compared to the other groups OB3 had a higher 30-day mortality (27% vs. 6%, 0.05). Multivariate analyses confi rmed BMI > 40 as an independent predictor of post-operative mortality. Conclusion: Obesity did not increase post-operative complications in veterans after liver resection. Mortality was higher in patients with BMI > 40

BACKGROUND: Bariatric operations significantly improve glucose metabolism, decrease insulin resistance, and lead to clinical resolution of type II diabetes mellitus in many patients. The mechanisms that achieve these clinical outcomes, however, remain ill defined. Moreover, the relative impact of various operations on insulin resistance remains vigorously contested. Consequently, the purpose of this study was to compare directly the impact of laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic adjustable gastric banding (LAGB) on hemoglobin A1c (HbA1c) levels and insulin resistance in comparable groups of morbidly obese patients. METHODS: Data were entered prospectively into our bariatric surgery database and reviewed retrospectively. Patients selected operations. Principle outcome variables were percent excess weight loss (%EWL), HbA1c, and homeostatic model assessment for insulin resistance (HOMA IR). RESULTS: The number of follow-up visits for 111 LAGB patients was 263 with a median of 162 days (17-1,016) and 291 follow-up visits for 104 LRYGB patients for a median of 150 days (8-1,191). Preoperative height, weight, body mass index, age, sex, race, comorbidities, fasting glucose, insulin, HbA1c, and HOMA IR were similar for both groups. In particular, the number of patients who were diabetics and those receiving insulin and other hypoglycemic agents were similar among the two groups. The LAGB patients lost significantly less weight than the LRYGB patients (24.6% compared to 44.0% EWL). LAGB reduced HbA1c from 5.8% (2-13.8) to 5.6% (0.3-12.3). LRYGB reduced HbA1c from 5.9% (2.0-12.3) to 5.4% (0.1-9.8). LAGB reduced HOMA IR from 3.6 (0.8-39.2) to 2.3 (0-55) and LRYGB reduced HOMA IR from 4.4 (0.6-56.5) to 1.4 (0.3-15.2). Postoperative HOMA IR correlated best with %EWL. Indeed, regression equations were essentially identical for LAGB and LRYGB for drop in %EWL versus postoperative HOMA IR. CONCLUSION: Percent excess weight loss significantly predicts postoperative insulin resistance (HOMA IR) during the first year following both LRYGB and LAGB.

BACKGROUND: An increasing importance has been placed on a bariatric program's readmission rates. Despite the importance of such data, there have been few studies that document 1-year readmission rates. There have been even fewer studies that delineate the causes of readmission. The objective of this study is to delineate the rates and causes of readmissions within 1 year of bariatric operations performed in a high-volume center. METHODS: Records for all patients undergoing bariatric operations during a 31-month period were harvested from the hospital electronic medical database. Readmissions for these patients were then identified within the hospital database for the year following the index operation. The electronic medical records of all readmitted patients were reviewed. RESULTS: The overall 1-year readmission rate for 1,939 consecutive bariatric operations was 18.8%. The laparoscopic adjustable gastric band (LAGB) had the lowest readmission rate of 12.69%. Next was the vertical banded gastroplasty-Roux-en-Y gastric bypass (VBG-RYGB) with a rate of 15.4%. The laparoscopic Roux-en-Y gastric bypass (LRYGB) had the highest readmission rate of 24.2%. Leading causes of readmission were abdominal pain with normal radiographic studies and elective operations. Independent factors predicting readmission were found to be LOS > 3 days (odds ratio 1.69 p = 0.004) and having a LRYGB (odds ratio of 1.49 p = 0.003). The previously reported reoperation rate for bowel obstruction of 9.7% had decreased to 3.7% due to changes in operative technique. CONCLUSION: Rates of readmissions for patients undergoing bariatric surgery center at our high-volume center decreased over time and are comparable to other major abdominal operations

BACKGROUND: The American Society of Bariatric Surgery has initiated a Bariatric Surgery Center of Excellence Program and the American College of Surgeons has followed with their Bariatric Surgery Center Network Accreditation Program. These programs postulate that concentration of weight loss operations in high-volume centers will decrease surgical mortality and improve outcomes. METHODS: The purpose of this study was to calculate the in-hospital mortality for bariatric operations accomplished at the highest volume bariatric surgery center in the state of New Jersey. After receiving Institutional Revew Board approval, the revised surgical schedule was used to identify all patients undergoing weight loss surgery (WLS) at Hackensack University Medical Center from 1998 through June, 2006. Data for these patients were then harvested from the hospital's electronic medical record. Step-wise and univariate logistic regression analysis tested the impact of various factors on hospital length of stay and in-hospital mortality. RESULTS: Between 1998 and June, 2006, 5,365 patients underwent WLS surgery: 2,099 open vertical banded gastroplasty-Roux en Y gastric bypass (VBG-RYGB); 2,177 laparoscopic Roux en Y gastric bypass (LRYGB); and 1,089 laparoscopic adjustable gastric banding (LAGB). 75.5% of patients were women. Median age was 41 years old (13-79), median weight 128 kg (81.2-290.3), and median body mass index 46.1 kg/m(2) (35.0-92.6). Median total operating room time for VBG-RYGB was 115 min (33-328); LRYGB 155 min (53-493), and LAGB 92 min (33-274). Median length of stay for VBG-RYGB was 3 days (1-39 days), LRYGB 2 days (1-46 days), and LAGB 1 day (1-20). Seven patients died in hospital after the 5,365 WLS operations (0.13%): four after VBG-RYGB (0.19%); three after LRYGB (0.14%); and none after LAGB (0%). The characteristics of the patients who died did not significantly differ from the group as a whole. CONCLUSION: Surgeons at Hackensack University Medical Center, a high volume, accredited 1A American College of Surgeons Bariatric Surgery Center, achieved a 0.13% mortality among 5,365 patients undergoing weight loss operations between 1998 and June, 2006. This study supports the concept that high-volume centers perform bariatric operations with low mortalities

BACKGROUND: We previously reported significantly longer operating room times and a trend toward increased complications and mortality in the super-super obese (body mass index [BMI] >/=60 kg/m(2)) early in our experience with laparoscopic Roux-en-Y gastric bypass. The goal of this study was to re-examine the short-term outcomes for super-super obese patients undergoing weight loss surgery at our high-volume bariatric surgery center well beyond our learning curve. METHODS: The records for all patients who had undergone weight loss surgery at Hackensack University Medical Center from 2002 to June 2006 were harvested from the hospital's electronic medical database. This population was analyzed as 2 groups (those with a BMI <60 kg/m(2) and those with a BMI >/=60 kg/m(2)), as well as by type of operation. Step-wise and univariate logistic regression analyses assessed the effect of BMI on the outcome variables, including mortality, length of surgery, length of hospital stay, and disposition at discharge. RESULTS: A total of 3692 patients were studied. Of these patients, 3401 had a BMI <60 kg/m(2) and 291 had a BMI >/=60 kg/m(2). Of the 291 super-super obese patients, 130 underwent vertical banded gastroplasty-Roux-en-Y gastric bypass, 116 laparoscopic Roux-en-Y gastric bypass, and 45 laparoscopic adjustable gastric banding. The proportion of male patients, black patients, and patients with sleep apnea was increased in the BMI >/=60 kg/m(2) group. The number of co-morbid diseases per patient correlated with age but not BMI. The BMI >/=60 kg/m(2) group required a significantly longer total operating room time (136 versus 120 min). Hospital length of stay was significantly longer only in the laparoscopic Roux-en-Y gastric bypass patients (3 d for the BMI >/=60 kg/m(2) group versus 2 d for the BMI <60 kg/m(2) group). A significantly greater percentage of patients in the super-super obese group were discharged to chronic care facilities. The overall in-hospital mortality rate was 0.15% (5 of 3692) but did not significantly differ between the 2 groups: BMI <60 kg/m(2), rate of 0.12% (4 of 3401 patients), and BMI >/=60 kg/m(2), rate of 0.34% (1 of 291 patients). The type of operation did not significantly affect the disposition at discharge or in-hospital mortality. CONCLUSION: Super-super obese patients required longer total operating room times, a longer hospital length of stay, and were more likely to be discharged to chronic care facilities than were patients with a BMI <60 kg/m(2); however, the in-hospital mortality was similar for both groups

BACKGROUND: Recent studies suggest that weight loss operations may actually increase the costs to society due to increased hospital readmission rates. The purpose of this study was to determine the 30-day readmission rates following bariatric operations at a high volume bariatric surgery program. METHODS: Records for all patients undergoing bariatric operations during a 3-year period were harvested from the hospital electronic medical database. All hospital readmissions within 30 days of surgery were reviewed to determine the cause, demographics, and patient characteristics. Logistic regression analysis assessed the impact of various factors on the risk of readmission. RESULTS: 2,823 consecutive patients were identified using the corrected operative log. Of these patients, 165 (5.8%) patients required 184 (6.5%) readmissions within 30 days of their index bariatric operation. Laparoscopic adjustable gastric banding (LAGB) had the lowest patient readmission rate of 3.1%; vertical banded gastroplasty-Roux-en-Y gastric bypass (VBG-RYGBP) 6.8% and Laparoscopic Roux-en-Y gastric bypass (LRYGBP) 7.3%. Technical considerations were the most common cause for readmission (41% of readmissions). White race and undergoing LAGB decreased the odds for readmission, while total operating-room time >120 minutes, initial hospital stay of >3 days and deep venous thrombosis increased the odds for readmission. CONCLUSION: This study found an overall 30-day readmission rate of 6.5% following bariatric operations at a high volume bariatric surgery program. This study supports the concept of bariatric surgery Centers of Excellence and accreditation of Bariatric Surgery Programs based on hospital volume of bariatric operations

OBJECTIVES: Genetically engineered tumor cells were used as a vaccine in a murine model to compare tumor formation after inoculating multiple sites versus a single site. The effect of vaccinating draining lymph node basins was evaluated. STUDY DESIGN: Mice were vaccinated in either the floor of the mouth, the draining nodes of the front legs, the hind leg, or a combination of sites. Seven days later, the mice were challenged with parental tumor cells in the floor of the mouth and followed for tumor growth. METHODS: A retroviral vector was used to transduce the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene into SCCFVII/SF tumor cells, which were then irradiated to prevent replication in vivo. Syngeneic C3H/HeJ mice were vaccinated with 1 x 10(6) cells in various sites, then challenged with 1 x 10(5) parental cells after 7 days. RESULTS: Animals vaccinated in multiple sites had better protection from later tumor challenge than those receiving single vaccinations. Of the animals receiving vaccination at multiple sites, those vaccinated in the site of tumor challenge (floor of the mouth) had more protection than those not vaccinated at the site. CONCLUSIONS: Mice vaccinated at multiple draining lymph node sites were better primed against tumor challenge than mice receiving single inoculations. Vaccination strategies that included the challenge site (floor of the mouth) and the nodes near this site were optimal

OBJECTIVES: Using a murine model, a novel tumor vaccine for head and neck squamous cell carcinoma expressing the granulocyte-macrophage colony stimulating factor (GM-CSF) gene was evaluated for its ability to protect against tumor challenge. STUDY DESIGN: Mice vaccinated in the floor of the mouth with the GM-CSF tumor cell vaccine were challenged with parental tumor cells, and subsequent tumor development was monitored. Specificity of the antitumor response was demonstrated by vaccinating the mice and then challenging them with an unrelated but syngeneic radiation-induced fibrosarcoma tumor cell line, RIF. Irradiated (only) tumor cells were used as a control to see whether an augmented antitumor response was attributable to possible increased immunogenicity that could theoretically be induced by the irradiation. METHODS: The GM-CSF gene was transduced into tumor cells via a retroviral vector. The tumor cells were irradiated to prevent replication in vivo. GM-CSF concentrations were determined using ELISA, and physiological activity was confirmed using a biological assay with a GM-CSF-dependent cell line. RESULTS: Vaccination with genetically engineered tumor cells significantly protected against subsequent tumor challenge (5% level) when compared to control groups. Mice were not protected when vaccinated and challenged with the unrelated tumor cell line, RIF. Mice vaccinated with irradiated (only) tumor cells were not protected, either. CONCLUSIONS: Vaccination with genetically engineered tumor cells offers significant protection from later tumor challenge. The response is systemic and tumor specific, not due to an inflammatory response. Irradiation of the tumor cells does not account for the augmented antitumor response. This work supports the continued investigation of the GM-CSF tumor vaccine for the treatment of head and neck squamous cell carcinoma