Changes in impedance planimetry metrics predict clinical response to flexible endoscopy in Zenker's diverticulotomy.

 Various techniques have been described for flexible endoscopic therapy for Zenker's diverticulum (ZD). Objective methods to assess myotomy effectiveness are lacking. We assessed the utility of impedance planimetry in flexible endoscopic ZD therapies and correlation with a validated symptom score.  Patients undergoing endoscopic therapy for symptomatic ZD from February 2019 to March 2020 were included. Intraprocedural impedance planimetry was performed pre- and post-myotomy to assess esophageal diameter and distensibility index (DI). Eating Assessment Tool (EAT)-10 scores were assessed preintervention and post-intervention. Descriptive statistics were calculated.  Thirteen patients (46 % women; mean age 80 years; 77 % peroral endoscopic myotomy technique) were included. Technical and clinical success was 100 %. No adverse events occurred. At 40 mL and 50 mL, the diameter improved (mean 2.3 mm and 2.6 mm, respectively). At 40 mL and 50 mL, the DI improved (mean 1.0 mm /mmHg and 1.8 mm /mmHg, respectively). EAT-10 scores improved by a mean of 15 points. Mean follow-up was 97 days. Intraprocedural impedance planimetry may provide objective data to define success for flexible endoscopic ZD. Further research is required to corroborate these results.