Arnold W. J. M. van de Laar

Bariatric Outcomes Longitudinal Database (BOLD) Suggests Excess Weight Loss and Excess BMI Loss To Be Inappropriate Outcome Measures, Demonstrating Better Alternatives

Excess weight loss (%EWL) results show significant variation by initial body mass index (BMI): the heavier the patient, the lower the result. It is unclear whether this effect originates from the arithmetic construction of this outcome measure or from any true difference in bariatric impact on heavier and lighter patients. Outcome measures generating inappropriate variation would actually be unsuited for bariatric reports with possible implications on existing bariatric evidence. Nadir weight loss results after laparoscopic gastric bypass in 7,212 women from the Bariatric Outcomes Longitudinal Database (BOLD) are calculated for %EWL and 26 different relative measures using the formula 100 % × (initial BMI − nadir BMI)/(initial BMI − a), with reference point 0 ≤ a ≤ 25. Variations by initial BMI and deviations in results using each relative measure are compared. Mean initial BMI, 47.5 kg/m2. Mean nadir BMI, 28.9 kg/m2. Mean nadir results of the lighter (A) and heavier (B) halves (2× n=3, 606) by reference point, a=25 (excess BMI loss (%EBMIL)), 95.3 % (A)–77.2 % (B); a=ideal weight (%EWL), 81.7 % (A)–70.4 % (B); a=10, 49.6 % (A)–49.7 % (B); a=0 (total weight loss (%TWL)), 37.7 % (A)–40.2 % (B). Variation by initial BMI is significant using all relative measures, except those with a = 9 (p = 0.396) and a = 10 (p = 0.504). The smallest variation coefficient is 21.5 % at 8 ≤ a ≤ 14. Gastric bypass works equally effective for all female patients, reducing the part of body mass above 10 kg/m2 by an average of 49.6 %, regardless of their initial BMI. In contrast, %EWL and %EBMIL generate variation by initial BMI, providing lighter patients inappropriately with better results, potentially interfering with the significance of bariatric evidence. These two most widespread used outcome measures in bariatric surgery are therefore actually unsuited for comparing patients or groups. This BOLD data makes a strong argument for abandoning %EWL and %EBMIL altogether and reporting bariatric relative outcome as %TWL only.

A novel fully covered double-bump stent for staple line leaks after bariatric surgery: a retrospective analysis

BackgroundStaple line leakage after bariatric surgery can be treated by endoscopic placement of a self-expandable stent. The success rate of stent placement is generally high, but migration is a frequent adverse event that hampers successful treatment. The Niti-S Beta stent is a fully covered double-bump stent that was specifically designed to prevent migration. This study aimed to evaluate the effectiveness and adverse event rate of the Niti-S Beta stent.MethodsA retrospective study was performed in three high-volume bariatric centers. All consecutive patients between 2009 and 2016 who underwent placement of a Beta stent for staple line leakage were included. Primary outcome was resolution of the leakage; secondary outcome was the adverse event rate including migration.ResultsThirty-eight patients were included. Twenty-five (66%) had resolution of the leakage. Success rate was higher in patients who were treated with implantation of a Beta stent as initial treatment (100%) than in patients who were treated with a stent after revisional surgery had failed (55%, p = 0.013). Migration occurred in 12 patients (32%). There were two severe adverse events requiring surgical intervention, including a bleeding from an aorto-esophageal fistula.ConclusionsThe success rate and the migration rate of the Beta stent seem comparable to other stents in this retrospective study. Despite the novel double-bump structure of the stent, the migration rate does not seem to be decreased.