484. DELTA-IRP AS A NEW HIGH-RESOLUTION MANOMETRY METRIC TO PREDICT THE POSITIVE OUTCOME OF LAPAROSCOPIC HELLER-DOR IN PATIENTS WITH ACHALASIA

Abstract Background There is no consensus on the definition of failure after treatment in patients with esophageal achalasia. The Eckardt score (ES) is commonly used to define clinical outcome, but objective metrics based on high-resolution manometry (HRM) or other tools are lacking. Aim of this study was to identify any HRM objective parameters useful to predict a positive outcome after surgical treatment with laparoscopic Heller-Dor (LHD). Methods Patients who had undergone LHD between 2012 and 2022, with pre- and postoperative HRM at our Center, were enrolled. Patients were divided according to the outcome of treatment between success group (SG, symptom relief or resolution) and failure group (FG, ES>3 or the need for additional treatment). Further to the traditional HRM metrics commonly evaluated, we also measured the difference between median values of pre- and postoperative Integrated Relaxation Pressure (∆-IRP). A ROC curve analysis was applied to assess the accuracy of each HRM parameter identified. Data are reported in Table 1. Results We enrolled 358 patients (F:M=177:187): 331 in the SG and 27 in the FG. The ∆-IRP was higher in SG [22mmHg (IQR:15-31)] than in FG [14.3mmHg (IQR:9.9-18.3), p=0.04]. The univariate analysis is showed in Table 1. At multivariate analysis, the ∆-IRP was the only parameter independently related to clinical success (p<0.01). The ROC curve for the ∆-IRP showed an area under the curve of 0.71, with a threshold value set at 16.55 mmHg (sensibility 71%, specificity 70%). Conclusions Our data showed that the ∆-IRP with a threshold of 16.5 mmHg could represent a new objective tool to predict the positive outcome of LHD in patients with esophageal achalasia.