USE OF IMPEDANCE PLANIMETRY IN THE DIAGNOSIS OF GASTRIC SLEEVE STENOSIS: THE ESTABLISHMENT OF NEW BENCHMARK VALUES

Background: Gastric sleeve stenosis (GSS) is an increasingly common adverse event following sleeve gastrectomy (SG) and thought to result from progressive rotation and/or scarring of the sleeve. Objective diagnostic criteria for this condition are lacking. Given the increasing prevalence of SG procedures being performed and the rising incidence of GSS, the diagnosis of GSS is critical to expedite management and reduce patient suffering. Endoluminal impedance planimetry measurements including diameter and distensibility indices (DI) show promise in characterizing GSS, though normal and abnormal benchmark values have never been established.
Aims: To (1) establish benchmark values for the distribution of diameter and DI for normal gastric sleeve anatomy and across GSS severity, and (2) determine if impedance planimetry measurements can be used to characterize the severity of GSS.
Methods: This was a retrospective analysis of a prospective database of patients who underwent upper endoscopy with impedance planimetry for suspected GSS between 8/2018 and 11/2022. All upper endoscopies were performed by a single trained bariatric endoscopist who assessed the presence and severity of luminal narrowing and was blinded to impedance planimetry measurements. Endoscopist description of endoluminal narrowing was reported as normal [0], mild [1], moderate [2], or severe [3]. Impedance planimetry measurements were obtained by advancing the catheter across the GSS. Measurements were monitored for 60 seconds with 3 different balloon volumes (30ml, 40ml, and 50ml) and diameter and distensibility index (DI) were recorded. Primary outcome included luminal diameter and DI. Secondary outcomes included presence and severity of GSS on endoscopy.
Results: A total of 110 endoscopic procedures were included. No luminal narrowing was seen in 19 (17%). Luminal narrowing was graded as mild, moderate, and severe in 27 (25%), 34 (30%), and 30 (27%) of procedures, respectively. When stratified by severity, there was significant difference between impedance planimetry measurements of diameter and DI in all four categories using all 3 balloon volumes (Figure 1). In the group without luminal narrowing, mean (±SD) diameter and DI measurements using consecutive balloon volumes ranged from 19.1 (±5.5) to 23.2 (±1.7) and 16.8 (±4.9) to 23.1 (±10.9), respectively. Comparatively, in severe narrowing, mean (±SD) diameter and DI measurements ranged from 10.3 (±3.0) to 16.6 (±2.1) and 7.5 (±7.1) to 7.7 (±4.3), respectively. Representative images of impedance planimetry for no luminal narrowing and mild, moderate, and severe stenosis are shown in Figure 2.
Conclusion: Impedance planimetry measurements provide objective assessment in the diagnosis of GSS and correlate with luminal narrowing. This study provides new benchmark values for the diagnosis and severity of GSS.