Evaluation of graft patency during minimally invasive coronary artery bypass grafting with Doppler flow analysis.

BACKGROUND

An objective method for determining intraoperative graft patency is an essential part of minimally invasive direct coronary artery bypass. This study compares angiography and Doppler methods for graft analysis during minimally invasive direct coronary artery bypass and presents long-term outcome in a cohort of patients.

METHODS

Between March and October 1997, 35 patients had elective minimally invasive direct coronary artery bypass procedures in which the left internal mammary artery was anastomosed to the left anterior descending coronary artery. Immediate graft patency was determined with intraoperative angiography using selective injection of the left internal mammary artery from a femoral approach and with Doppler flow analysis using a 1-mm, 20-MHz Doppler probe placed directly on the graft.

RESULTS

There was immediate perfect patency with brisk flow in 91% of patients (32 of 35). A normal Doppler study, defined as a diastolic predominant pattern with a diastolic flow velocity of greater than 15 cm/second, was found in all patients with normal angiograms. All patients with abnormal angiograms also had abnormal Doppler flow. Thus, Doppler analysis was 100% accurate for confirming graft patency and for detecting failed grafts. All abnormal grafts were successfully revised, which allowed 100% early patency. Operative mortality was 2.8% (1 of 35) and there have been no late deaths at a follow-up of more than 2 years. One patient required angioplasty of the anastomosis (1 of 34, 2.9%), but none have required subsequent surgical intervention.

CONCLUSIONS

Objective analysis of graft flow in the operating room is necessary to achieve 100% early graft patency with minimally invasive direct coronary artery bypass operations. Doppler analysis is the preferred initial method, because it is safe, accurate, and rapid.