Delayed Gastric Emptying After Sleeve Gastrectomy Is Associated with Poor Weight Loss.

BACKGROUND: Intermediate to long-term weight regain is a major challenge following sleeve gastrectomy (SG). Physiological changes that mediate the extent of weight loss remain unclear. We aimed to determine if there were specific esophago-gastric transit and emptying alterations associated with weight regain. MATERIAL AND METHODS: Participants greater than 12 months post-SG were categorized into optimal (n = 29) and poor weight loss (PWL) (n = 72). All patients underwent a liquid contrast barium swallow demonstrating normal post-surgical anatomy and a protocolized nuclear scintigraphy designed specifically to characterize gastric emptying following SG. RESULTS: The %total weight loss in the optimal group was 26.2 ± 10.5 vs. 14.3 ± 8.8% in the PWL group (p = 0.001). Scintigraphy showed PWL had relatively increased gastric emptying half-time (GE 1/2t) 35 (IQR 23) min vs 19 (IQR 5.5) min (p = 0.001). The multivariate regressions delineated GE 1/2t as the best diagnostic measure for PWL (OR 1.16; CI 1.04-1.29, p-value 0.021). The probability of PWL increased by 16% for every 1-min increase above 21 min of GE 1/2t. A threshold of 21 min was found to have 88% sensitivity and 69% specificity predicting poor weight loss. CONCLUSION: Gastric emptying half-times greater than 21 min appear to reliably correlate with poor weight loss following SG. Additionally, further elevations above 21 min in emptying half-time increase the risk of poor weight loss. We have shown nuclear scintigraphy represents a simple and accurate diagnostic tool in patients who experience poor weight loss after SG, provided substantially altered reporting references in interpreting nuclear scintigraphy are applied.

Long-Term Outcomes of Revisional Malabsorptive Bariatric Surgery: Do the Benefits Outweigh the Risk?

PURPOSE: To evaluate the long-term outcomes of revisional malabsorptive bariatric surgery. MATERIALS AND METHODS: Malabsorptive bariatric procedures are increasingly performed in the revisional setting. We collated and analysed prospectively recorded data for all patients who underwent a revisional Biliopancreatic diversion + / - duodenal switch (BPD + / - DS) over a 17-year period. RESULTS: We identified 102 patients who underwent a revisional BPD + / - DS. Median follow-up was 7 years (range 1-17). There were 21 (20.6%) patients permanently lost to follow-up at a median of 5 years postoperatively. Mean total weight loss since the revisional procedure of 22.7% (SD 13.4), 20.1% (SD 10.5) and 17.6% (SD 5.5) was recorded at 5, 10 and 15 years respectively. At the time of revisional surgery, 23 (22.5%) patients had diabetes and 16 (15.7%) had hypercholesterolaemia with remission of these occurring in 20 (87%) and 7 (44%) patients respectively. Nutritional deficiencies occurred in 82 (80.4%) patients, with 10 (9.8%) patients having severe deficiencies requiring periods of parenteral nutrition. Seven (6.9%) patients required limb lengthening or reversal procedures. There were 16 (15.7%) patients who experienced a complication within 30 days, including 3 (2.9%) anastomotic leaks. Surgery was required in 42 (41.2%) patients for late complications. CONCLUSION: Revisional malabsorptive bariatric surgery induces significant long-term weight loss and comorbidity resolution. High rates of temporary and permanent attrition from follow-up are of major concern, given the high prevalence of nutritional deficiencies. These data question the long-term safety of malabsorptive bariatric procedures due to the inability to ensure compliance with nutritional supplementation and long-term follow-up requirements. KEY POINTS: • Revisional bariatric surgery workload is increasing • Revisional malabsorptive surgery is efficacious for weight loss and comorbidity resolution • Revisional malabsorptive surgery is associated with high rates of nutritional deficiencies • Attrition from follow-up in this specific cohort of patients is of particular concern due to the risk of undiagnosed and untreated nutritional deficiencies.

Validity of multi-frequency bioelectric impedance methods to measure body composition in obese patients: a systematic review.

OBJECTIVE: Excessive lean tissue loss following bariatric surgery may pose serious metabolic consequences. Accurate methods to assess body composition following bariatric surgery are required. This review aimed to investigate if multi-frequency bioelectric impedance (MF-BI) is a valid tool to determine body composition in obese patients. METHODS: MEDLINE, EMBASE, CINAHL and CENTRAL databases were searched until March 2017. Included studies were published in English with obese (body mass index (BMI) ≥ 30 kg/m2) adults measuring body composition with MF-BI methods in comparison with reference methods. Exclusions were pregnancy, animal studies, non-English language studies, single frequency BI. A total of 6395 studies were retrieved. RESULTS: Sixteen studies were eligible for inclusion. Sample sizes ranged from 15 to 157, with BMI 26-48 kg/m2. MF-BI underestimated fat mass (FM) in 11 studies and overestimated fat-free mass (FFM) in nine studies in comparison with reference methods. Correlations of absolute values from MF-BI and reference methods for FM and FFM were high, however, agreement was lower at an individual level. When adjustments for BMI were made to machine algorithms, measurement accuracy improved. Significant heterogeneity was evident among included studies. CONCLUSIONS: This review found that MF-BI is reliable for use at a group level. Obese-specific adjustment of algorithms for MF-BI machines increases the accuracy of absolute measures of body composition in obese individuals, improving their utility in the clinical setting. Multiple variables contributed a lack of consistency among studies included, highlighting the need for more robust studies that control confounding variables to establish clear validity assessment.