# First-in-Man Use of Intraoperative Electrophysiological Mapping to Evaluate the Efficacy of the EnCompass Clamp During a Cox-IV Maze Procedure

## TL;DR

This case report shows how a new surgical tool, the EnCompass clamp, was used during heart surgery to treat atrial fibrillation, with real-time mapping confirming its effectiveness.

## Contribution

This is the first reported use of intraoperative electrophysiological mapping to assess the EnCompass clamp during a Cox-IV Maze procedure.

## Key findings

- Intraoperative EP mapping showed an 88% reduction in high-voltage areas after using the EnCompass clamp.
- The final map after the full Cox-IV Maze procedure showed near-complete electrical silence in the atria.
- The EnCompass clamp allows ablations with a beating heart, reducing ischemia time.

## Abstract

This case report describes the first-in-man use of intraoperative electrophysiological (EP) mapping to evaluate the efficacy of the EnCompass clamp (AtriCure, Inc., Mason, OH) during a Cox-IV Maze procedure. A 53-year-old male with paroxysmal atrial fibrillation and severe mitral valve regurgitation underwent mitral valve repair with concomitant surgical ablation for atrial fibrillation. Intraoperative 3D EP mapping was performed using the Abbott EnSite Precision system (Abbott Inc., Chicago, IL) before ablation, after initial radiofrequency ablation with the AtriCure EnCompass clamp, and after the full Cox-IV Maze procedure was completed.

The pre-ablation map showed approximately 80-85% high voltage areas in the posterior left atrial wall. Initial ablation with the EnCompass clamp reduced high voltage areas to 30-35%. The final map following the Cox-IV Maze procedure demonstrated near-complete electrical silence, with only 5-10% of the atrial surface retaining high voltage activity. This represents an estimated 88% reduction in high-voltage areas from baseline. The patient had an uncomplicated postoperative course apart from one episode of postoperative atrial fibrillation requiring direct current (DC) cardioversion.

This case demonstrates the utility of intraoperative EP mapping in guiding and confirming the efficacy of surgical ablation procedures, as well as the effectiveness of combining the EnCompass clamp with a full Cox-IV Maze in achieving comprehensive atrial electrical isolation. The EnCompass clamp can be used for ablations with a beating heart, thus reducing the aortic cross-clamp time and therefore minimizing the total myocardial ischemia time.