Quantification of gastric sleeve stenosis using endoscopic parameters and image analysis

Background and Aims: Sleeve gastrectomy has quickly become the most commonly performed bariatric surgery. In light of its increasing popularity, the prevalence of gastric sleeve stenosis (GSS) continues to rise. Management with serial pneumatic dilation is highly successful but underused because of a lack of quantitative diagnostic criteria. We aimed to develop quantifiable endoscopic criteria to characterize GSS based on the (1) ratio of narrowest to widest gastric lumen diameter, (2) endoscope angulation/trajectory required for passage, and (3) presence of bilious fluid pooling in the proximal sleeve and compare it with endoluminal functional lumen imaging probe (EndoFLIP) diameter and distensibility indices (DIs) and endoscopic documentation of gastric lumen morphology. Methods: We retrospectively reviewed a prospectively maintained database of patients undergoing endoscopy to assess for GSS. Endoscopic images were reviewed in a blinded fashion by 2 bariatric endoscopists. The narrowest and widest part of the gastric lumen diameters were noted on each image, in addition to a hypothetical trajectory required for endoscope passage. Using image processing software, we calculated the the ratio of diameters (ie, narrowest divided by widest) and angle of endoscope trajectory. The presence of bilious fluid pooling in the proximal gastric lumen was noted. These values were then compared with EndoFLIP parameters and endoscopic documentation of gastric lumen morphology. Results: Thirty patients met inclusion criteria, and 26 (87%) were found to have a stenosis on endoscopy. Of those, 9 (35%) were characterized as mild, 11 (42%) as moderate, and 6 (23%) as severe. There was no difference in demographic information between patients with and without stenosis. In patients with stenosis, mean EndoFLIP diameters and DIs were 12.9 ± 3.9 mm and 11.0 ± 6.8 mm²/mm Hg, respectively. In patients without stenosis, mean EndoFLIP diameters and DIs were 19.9 ± 2.9 mm and 21.5 ± 1.0 mm²/mm Hg, respectively. Patients with stenosis had significantly lower diameter ratios compared with those without stenosis (.27 ±.14 vs.48 ±.77, P =.01). Diameter ratios were also inversely related to severity of sleeve stenosis (β = –.08, P =.01). Patients with stenosis were also more likely to have fluid pooling (96.2% vs 25%, P <.001). There was no significant difference in the trajectory of endoscope passage between the 2 groups. Conclusions: Endoscopic criteria for diagnosis of GSS are lacking. Our data suggest the ratio between the narrowest and widest gastric lumen diameters and presence of pooled fluid is associated with diagnosis of stenosis by EndoFLIP and gastric lumen morphology. Future studies to validate these criteria are needed.