Hybrid Procedure Overview and Lesion Set
In the Hybrid Convergent procedure (Figure 1), a multidisciplinary heart care team approach is utilized, first with a surgeon performing an epicardial ablation and then with an electrophysiologist following with an endocardial ablation. The minimum aspects of this lesion set involve electrical isolation of the posterior wall and pulmonary veins, with esophageal heating mitigated by device design and procedural best practices. The epicardial ablation procedure is focused on the posterior wall, utilizing a vacuum-assisted unipolar radiofrequency device inserted through a cannula with an endoscope. A transdiaphragmatic or more commonly a subxiphoid approach is used to access the pericardium. Epicardial ablations are applied across the posterior wall of the left atrium creating contiguous, parallel lesions. Current convergent ablation relies on the homogenization of the posterior wall in a more simplified manner complementary to the endocardial ablation as opposed to prior versions that were more extensive to replicate a Maze-like lesion set including a posterior wall box and bi-atrial lesions.21 Following the epicardial ablation by the surgeon, endocardial mapping guides the endocardial ablation performed using an irrigated radiofrequency catheter by the electrophysiologist, connecting any breakthrough gaps in lesions and thus completely isolating the left and right pulmonary veins. Confirmation of isolation is done by evaluating entrance and/or exit block to ensure the absence of conduction. Most studies on hybrid convergent procedures relied on commercially available radiofrequency endocardial catheters. Retrospective single-center and registry analyses have reported the safety and efficacy of endocardial cryoballoon catheters in the Hybrid Convergent procedure.22-24