723 QUANTIFICATION OF GASTRIC SLEEVE STENOSIS UTILIZING 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, due to lack of quantitative diagnostic criteria. We aimed to develop quantifiable endoscopic criteria to characterize GSS based on (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 to endoluminal functional lumen imaging probe (EndoFLIP) diameter and distensibility indices (DI) 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 (Figure 1A), in addition to a hypothetical trajectory required for endoscope passage (Figure 1B). Using image processing software (ImageJ, U. S. National Institutes of Health, Bethesda, Maryland, USA, https://imagej.nih.gov/ij/, 1997-2018), the ratio of diameters (ie, narrowest divided by widest) and angle of endoscope trajectory was calculated. The presence of bilious fluid pooling in the proximal gastric lumen was noted. These values were then compared to 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%) were moderate and 6 (23%) were severe. There was no difference in demographic information between patients with and without stenosis (Table 1). In patients with stenosis, mean EndoFLIP diameters and DI were 12.9 (± 3.9) mm and 11.0 (± 6.8) mm2/mm Hg, respectively. In patients without stenosis, mean EndoFLIP diameters and DI were 19.9 (± 2.9) mm and 21.5 (± 1.0) mm2/mm Hg, respectively. Patients with stenosis had significantly lower diameter ratios compared to those without stenosis (0.27 ± 0.14 vs 0.48 ± 0.77, p=0.01). Diameter ratios were also inversely related to severity of sleeve stenosis (s = -0.08, p=0.01). Patients with stenosis were also more likely to have fluid pooling (96.2% vs 25%, p Conclusion 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.