Faculty Bibliography

Background/Purpose : Weight loss in obese patients can reduce knee osteoarthritis (OA) pain, even when physical therapy and intra-articular injections have failed. The impacts of either non-surgical or surgical weight loss on knee OA pain have been reported separately, but few studies have assessed them conjointly. While the decrease in mechanical load helps, the contribution of metabolic changes is less clear. We aimed to compare biomarker changes with weight loss as predictors of knee pain improvement, and consider a threshold of total weight loss necessary for these changes. Methods : Patients from the NYU Langone Weight Management program were screened for knee pain prior to bariatric surgery or the start of a medical weight loss (MWL) regimen. We excluded patients with autoimmune disease, recent malignancy, recent intra-articular knee injections, and lack of OA by Kellgren-Lawrence (KL) x-ray grading. The BMI, Knee Injury and Osteoarthritis Outcome Score (KOOS) for pain, and blood samples were obtained at baseline and 1, 3, 6 and 12 months for evaluation of pain and biomarker levels. Results : Of 140 patients screened, 81 were eligible and enrolled (82.7% female; BMI 45.2+/-9.6 kg/m2, 31-74; age 52+/-12 years, 30-80). A total of 49 patients had surgery (10 bypass, 30 sleeve, 9 LapBand) and 24 medical weight loss. 33 patients completed visits up to 6 months (2 bypass, 18 sleeve, 6 LapBand, 7 MWL). By 1 month, the surgical patients had lost much more total weight than the MWL group (9.8% vs 4.1 %, p=0.001), and realized marked pain relief (p< 0.001). By 6 months both groups had continued to lose weight, proportionately greater for surgical patients with further pain improvement. (Figure 1) Leptin levels dropped at 1 and then 6 months with both methods of weight loss. The pro-inflammatory protein IL-1Ra decreased significantly by 6 months in the bariatric patients, but increased with the medical regimen across both time points. Soluble vascular adhesion protein 1 (sVAP-1), another pro-inflammatory protein that facilitates leukocyte infiltration, decreased at both the 1 and 6 month intervals -but much more in MWL than in surgical patients. Consistent with the literature, the anti-inflammatory soluble receptor for advanced glycation endproducts (sRAGE) mirrored KOOS pain improvement only in surgical patients and stabilized after 1 month, but did not change in the MWL group. (Table 1) In a subgroup analysis, the 14 surgical patients who lost at least 10% of Figure 1. Surgical and medical outcomes for % total weight loss (TWL), knee pain and biomarkers Table 1. total weight by 1 month had significantly less pain at 6 months than the 12 who did not meet the threshold (DELTAKOOS 47.5 vs 29.9) but the biomarker levels were similar. (Figure 2) Conclusion : Surgical and medically supervised weight loss both lead to significant decreases in adiposity, but only those having bariatric surgery realize significant pain relief. The anatomical changes of surgical (vs. medical) weight loss result in different metabolic cascades given divergent biomarker trends. Bariatric patients who lose more than 10 percent of total body weight within the first month are more likely to have better pain relief by 6 months, but the biomarker changes reflect anatomic intervention -and are not dependent on the degree of surgical weight loss

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: The gastrojejunostomy (GJ) during Roux-en-Y gastric bypass (RYGB) can be performed by stapled or hand-sewn techniques, and is at risk for anastomotic stricture, reported in the literature at rates from 0 to 33%. This study reviews a single center's experience with anastomotic stricture and intervention required. Methods and Procedures: A retrospective chart review was performed of 904 patients who underwent RYGB as primary or revisional surgery at a single institution from October 2000 through September 2017. There were 182 patients excluded for follow up duration of less than 1 year, 5 for an esophagojejunostomy rather than GJ, and 1 for gastroparesis as the surgical indication rather than morbid obesity. This left 716 patients to be included in the study. Demographic and operative data were collected including technique for GJ, postoperative follow up, and complications, with a focus on GJ stricture and subsequent interventions.
Result(s): Gastrojejunostomy (GJ) was performed with a 25 CEEA stapler in 674 (94.1%) patients, with a linear stapler in 25 (3.5%), was hand-sewn in 7 (1.3%), and the technique was unknown in the remaining 8 (1.1%). Roux-en-Y gastric bypass was performed as a primary surgery in 522 (72.9%) patients and as a revisional surgery in 194 (27.1%). Stricture of the GJ was diagnosed in 29 (4.1%) patients. The average time to diagnosis of early strictures occurring prior to 3 months was 40.3 days, and for late strictures was 871 days. By technique, stricture was diagnosed in 26 (3.9%) patients in the 25CEEAgroup, 1 (4%) in the linear stapler group, and 2 (22.2%) in the hand-sewn anastomosis group. In primaryRYGBpatients stricture was diagnosed in 20 (3.8%) patients, and in revisionalRYGB in 9 (4.6%) patients (p = 0.626). Esophagogastroduodenoscopy (EGD) with dilation was performed at least once (1-9 times) in 26 patients, 2 with concomitant stenting, 2 required operative intervention, and 1 patient awaits operative intervention. Both patients who required surgery also had marginal ulcers, and possible gastro-gastric fistula at time of surgery.
Conclusion(s): The results of this study show that the 25 CEEA circular stapler is a reasonable technique for performance of the GJ anastomosis in RYGB, with a stricture rate of 3.9%. There is also a slightly increased stricture rate in revisional surgical patients, though not statistically significant

BACKGROUND:When administered as a continuous infusion, ketamine is known to be a potent analgesic and general anaesthetic. Recent studies suggest that a single low-dose administration of ketamine can provide a long-lasting effect on mood, but its effects when given in the postoperative period have not been studied. OBJECTIVE:We hypothesised that a single low-dose administration of ketamine after bariatric surgery can improve pain and mood scores in the immediate postoperative period. DESIGN/METHODS:We performed a randomised, double-blind, placebo-controlled study to compare a single subanaesthetic dose of ketamine (0.4 mg kg) with a normal saline placebo in the postanaesthesia care unit after laparoscopic gastric bypass and gastrectomy. SETTING/METHODS:Single-centre, tertiary care hospital, October 2014 to January 2018. PATIENTS/METHODS:A total of 100 patients were randomised into the ketamine and saline groups. INTERVENTION/METHODS:Patients in the ketamine group received a single dose of ketamine infusion (0.4 mg kg) in the postanaesthesia care unit. Patients in the placebo groups received 0.9% saline. OUTCOME MEASURES/METHODS:The primary outcome was the visual analogue pain score. A secondary outcome was performance on the short-form McGill's Pain Questionnaire (SF-MPQ). RESULTS:There were no significant differences in visual analogue pain scores between groups (group-by-time interaction P = 0.966; marginal group effect P = 0.137). However, scores on the affective scale of SF-MPQ (secondary outcome) significantly decreased in the ketamine group as early as postoperative day (POD) 2 [mean difference = -2.2 (95% bootstrap CI -2.9 to 1.6), Bonferroni adjusted P < 0.001], compared with placebo group in which the scores decreased only by POD 7. Scores on the total scale of SF-MPQ for the ketamine group were smaller compared with the placebo group (P = 0.034). CONCLUSION/CONCLUSIONS:Although there was no significant difference between ketamine and placebo for the primary outcome measure, patients who received ketamine experienced statistically and clinically significant improvement in their comprehensive evaluation of pain, particularly the affective component of pain, on POD 2. However, future studies are needed to confirm the enduring effects of ketamine on the affective response to postoperative pain. CLINICAL TRIAL REGISTRATION/BACKGROUND:NCT02452060.

BACKGROUND:Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are often used as revisional surgeries for a failed laparoscopic adjustable gastric band (LAGB). There is debate over which procedure provides better long-term weight loss. OBJECTIVE:To compare the weight loss results of these 2 surgeries. SETTING/METHODS:University hospital, United States. METHODS:A retrospective review was conducted of all LAGB to RYGB and LAGB to LSG surgeries performed at a single institution. Primary outcomes were change in body mass index (BMI), percent excess BMI lost, and percent weight loss. Secondary outcomes included 30-day complications and reoperations. RESULTS:The cohort included 192 conversions from LAGB to RYGB and 283 LAGB to LSG. The baseline age and BMI were similar in the 2 groups. Statistical comparisons made between the 2 groups at 24 months postconversion were significant for BMI (RYGB = 32.93, LSG = 38.34, P = .0004), percent excess BMI lost (RYGB = 57.8%, LSG = 29.3%, P < .0001), and percent weight loss (RYGB = 23.4%, LSG = 12.6%, P < .0001). However, the conversion to RYGB group had a higher rate of reoperation (7.3% versus 1.4%, P = .0022), longer operating room time (RYGB = 120.1 min versus LSG = 115.5 min, P < .0001), and longer length of stay (RYGB = 3.33 d versus LSG = 2.11 d, P < .0001) than the LAGB to LSG group. Although not significant, the conversion to RYGB group had a higher rate of readmission (7.3% versus 3.5%, P = .087). CONCLUSION/CONCLUSIONS:Weight loss is significantly greater for patients undergoing LAGB conversion to RYGB than LAGB to LSG. However, those undergoing LAGB conversion to RYGB had higher rates of reoperation and readmission. Patients looking for the most effective weight loss surgery after failed LAGB should be advised to have RYGB performed, while also understanding the increased risks of the procedure.

BACKGROUND:Studies reporting revisionary options for weight loss failure after Roux-en-Y gastric bypass (RYGB) have been underpowered and lacking long-term data. We have previously shown that short-term (12 mo) and midterm (24 mo) weight loss is achievable with laparoscopic adjustable gastric banding (LAGB) for failed RYGB. The present study represents the largest published series with longest postoperative follow-up of patients receiving salvage LAGB after RYGB failure. OBJECTIVE:To investigate long-term results of salvage gastric banding. SETTING/METHODS:University Hospital, New York, United States. METHODS:Data were prospectively collected with retrospective review. Baseline characteristics were evaluated and weights at multiple time intervals (before RYGB, before LAGB, each year of follow-up). Additional data included approach (open or laparoscopic), operative time, hospital length of stay, and postoperative complications. RESULTS:with 22.5% total weight loss and 65.9% excess weight loss. The long-term reoperation rate for complications related to LAGB was 24%, and 8% of patients ultimately had their gastric bands removed. CONCLUSION/CONCLUSIONS:The results of our study have shown that LAGB had good long-term data as a revisionary procedure for weight loss failure after RYGB.

INTRODUCTION/BACKGROUND:Bariatric surgery reduces obesity and knee osteoarthritis (OA) pain, but some patients improve more than others. We aimed to identify characteristics that predict this knee pain improvement. METHODS:We reviewed NYU Langone Health bariatrics records (2002-2015) and called eligible patients reporting pre-operative knee pain. Patients were asked to rate their pain on a 10-point scale at three time points: before surgery, one year post-surgery, and time of survey administration. Subjects were asked about pre-operative knee injuries and surgeries, presence of OA in other joints, and OA family history. Data were analyzed using paired t-tests and ANOVA. RESULTS:Of 125 eligible patients reporting knee pain, we analyzed the 120 patients who had laparoscopic gastric band (LAGB) surgery. The cohort was 78.3% female, with an average age at surgery of 49.7 ± 10.2 years. There was no correlation between pre-operative body mass index (BMI) and knee pain reduction at one year post-LAGB, but the subgroup with the most BMI improvement reported the most knee improvement (p = 0.043). We found significantly better pain reduction after one year in younger patients (p = 0.009). Those with prior knee injuries improved less than those who were injury-free (p = 0.044), but a history of prior knee surgery was not similarly significant. Patients with multifocal OA improved less (p = 0.001). CONCLUSION/CONCLUSIONS:Younger knee OA patients and those without prior knee injury or other OA involvement, experience more knee pain relief from LAGB weight loss surgery. LAGB may be a viable treatment option for knee OA pain, irrespective of the degree of obesity.