AN ANALYSIS OF THE CORRELATION BETWEEN INTRAOPERATIVE ENDOFLIP DISTENSIBILITY INDEX AND ESOPHAGEAL MANOMETRY LOWER ESOPHAGEAL SPHINCTER BASAL MEAN PRESSURE IN PATIENTS UNDERGOING ANTI-REFLUX SURGERY

Background: The type of fundoplication that would most benefit any given patient undergoing anti-reflux surgery is confounded by preoperative and intraoperative measures which may suggest different surgical choices. The purpose of this study was to evaluate the relationship between preoperative lower esophageal sphincter (LES) basal mean pressure using esophageal manometry and intraoperative gastroesophageal distensibility index (DI) using EndoFLIP following crural dissection during anti-reflux surgery.
Methods: A retrospective chart review was conducted of patients with gastroesophageal reflux disease who underwent preoperative esophageal manometry evaluation and anti-reflux surgery with the use of EndoFLIP intraoperatively between December 2020 and July 2023. Data collected included LES basal mean pressure from manometry and intraoperative fundoplication EndoFLIP measurements including (1) Minimum Diameter (Dmin), (2) DI, and (3) Intra-bag Pressure at 30cc’s and 40cc’s, measured at three intra-operative time points: (1) after crural dissection, (2) after crural closure, and (3) post-fundoplication. Data for DI was not normally distributed, so a logarithm transformation (logDI) was used in the analysis. Data analysis included descriptive statistics, scatterplots, and Pearson’s Correlation Coefficient.
Results: A total of 117 patients met the inclusion criteria. The majority (61.5%) of the sample were females (n=72) with a mean age of 61.0 years (standard deviation, 13.7), mean BMI of 27.8 (4.4), mean LES respiratory pressure of 19.9 (12.6), and mean DI measured at 40cc after crural dissection of 5.8 (5.2). Procedures performed were magnetic sphincter augmentation (LINX) (38.5%), followed by Toupet partial fundoplication (33.3%), Watson partial fundoplication (23.9%), Nissen fundoplication (3.4%), and transoral incisionless fundoplication (0.9%). There was a significant inverse correlation between LES basal mean pressure and logDI measured at 40cc following crural dissection r=-0.27 (p=0.003). Scatterplots were created to discern the value of LES basal mean pressure which more accurately predicts a cutpoint of DI informing the best type of anti-reflux surgery for optimal outcomes, but no range or specific value was observed.
Conclusion: There was a significant inverse relationship between LES basal mean pressure measured on manometry and lower esophageal DI following crural dissection during anti-reflux surgery. The lower the basal mean pressure, the higher the DI of the dissected esophageal crura found during anti-reflux surgery. Surgeons may be able to use pre-operative LES pressure to choose the type of fundoplication that will most benefit a patient seeking relief from reflux symptoms. Future research should attempt to identify an LES basal pressure measurement range or cluster that suggests a high intraoperative DI to guide surgical management.