Objective: Robotically assisted minimally invasive direct coronary artery bypass is an alternative to sternotomy-based surgery in properly selected patients. Identifying the left anterior descending artery when it is deep in the epicardial fat can be particularly challenging through a 5- to 6-cm mini-thoracotomy incision. The objective of this study was to evaluate a technique for predicting conversion to sternotomy or complicated left anterior descending artery anastomosis using preoperative cardiac-gated computed tomography angiograms.
Methods: Retrospective review of 75 patients who underwent robotically assisted minimally invasive direct coronary artery bypass for whom a preoperative computed tomography angiogram was available. The distance from the left anterior descending artery to the myocardium was measured on a standardized "5-chamber" axial computed tomography view. The relative risk of sternotomy or complicated anastomosis was compared between patients whose left anterior descending artery was resting directly on the myocardium (left anterior descending artery to the myocardium distance = 0 mm) with those whose left anterior descending artery was resting above (left anterior descending artery to the myocardium distance > 0 mm).
Results: The average left anterior descending artery to the myocardium distance was 3.2 ± 2.6 mm (range = 0-11.5 mm). Fourteen patients (18.7%) had an left anterior descending artery to the myocardium distance of 0 mm. Of the entire group of 75 patients, 6 (8.0%) required conversion to sternotomy. Four others (5.3%) were reported to have a complication with the anastomosis intraoperatively. For patients with left anterior descending artery to the myocardium distance of 0 mm, the relative risk of sternotomy or complicated anastomosis was 18.0 (95% confidence interval = 4.3-75.6, P = 0.0001).
Conclusions: In our experience, patients with left anterior descending artery to the myocardium distance of 0 mm were at significantly higher risk of either conversion to sternotomy or technically challenging anastomosis, with 8 (57.1%) of 14 patients in this group experiencing either end point. This novel measurement may be useful to identify patients who may have anatomy, which is not well suited to the robotically assisted minimally invasive direct coronary artery bypass approach.