Unveiling the endothelialization process of the WATCHMAN FLX Pro: beyond the resolution of conventional imaging

We enrolled 10 patients(12 evaluations) undergoing atrial fibrillation ablation following WATCHMAN FLXPro implantation. We compared the degree of device endothelialization assessed by endoscopic imaging with patient characteristics. Device endothelialization was classified into four grades(eGrade 1-4). Effective endothelialization was defined as eGrade 3(Semi-opaque) or higher. All endoscopies were performed beyond 2 months following the implantation. The distribution of endothelialization was: eGrade 1(Absent, n = 2), eGrade 2(Translucent, n = 2), eGrade 3(Semi-opaque, n = 3), and eGrade 4(Opaque, n = 3). The endoscopic endothelialization grade tended to be associated with the interval since implantation, persistent atrial fibrillation, and prior discontinuation of oral anticoagulants. Endothelialization progressed from the atrial wall where the device was anchored. Although endothelialization at the central hub was delayed, solid tissue coverage was observed around the hub in a few cases.