A novel clock-face method for characterizing peridevice leaks after left atrial appendage occlusion

Objectives: To propose a novel method for mapping leak location and frequency to a clock-face representation of the left atrial appendage (LAA) ostium. Background: LAA occlusion with the Watchman device (WD) is an established therapy to reduce thromboembolic events in patients with atrial fibrillation (AF) and intolerance to long-term oral anticoagulation. Postimplantation leaks are known sequelae, but leak locations and characteristics are poorly described. Methods: We retrospectively reviewed 101 consecutive WD implants from April 2015 to February 2018. Leak locations from 6-week post-implant transesophageal echocardiograms were mapped to a clock-face representation of the LAA ostium: 12:00 as cranial near the limbus, 3:00 as anterior toward the pulmonary artery, 6:00 as caudal near the mitral annulus, and 9:00 as posterior. Patient demographics, LAA dimensions, and procedural characteristics were also collected. Results: Thirty-four patients had ≥1 leak totaling 45 leaks at 6-week follow-up. Baseline patient demographics showed a mean age 77, CHA₂DS₂VASc 4.69, and 64% of patients with permanent AF. No patient had a detectable leak at the time of implant. At 6 weeks, mean leak size was 2.67 ± 0.89 mm with no leak over 5 mm (largest 4.60 mm). Most leaks occurred along the posterior 6:00–12:00 segment (39/45) and the 6:00–9:00 quadrant (16/45). Conclusion: Six-week post-WD implant leaks localize to the posterior LAA ostium. This could result from the elliptical LAA orifice, differential LAA tissue composition, or implantation technique. This study provides a novel method for describing the location of post-implant leaks and serves as the basis for further investigations.