Use of graft flow measurement and computerized tomography angiography to evaluate patency of endoscopically harvested radial artery as sequential graft in coronary artery bypass surgery

Abstract

Aim: Endoscopic radial artery (RA) graft harvesting in coronary artery bypass surgery (CABG) is attractive but concern remains regarding early graft failure. We evaluated RA graft patency via intraoperative graft flow measurements and mid-term computerized tomography angiography (CTA).

Methods: The patients who had RA harvested by endoscopic technique which was used as sequential grafts were retrospectively reviewed. Graft quality was confirmed by intraoperative transit time flow measurements. Graft stenosis was defined as stenosis >70% on CTA, 6-12 months postoperatively.

Results: From 2007 to 2011, 58 patients underwent endoscopic RA harvesting for sequential bypassed grafts. All received total arterialized grafts, including 22 (38%) bilateral internal thoracic arteries (ITAs), with 208 total bypassed grafts (mean: 3.59±0.52) and 128 RA bypassed grafts (mean: 2.21±0.35). Off-pump technique was performed in 43 (84%) of 51 isolated CABG patients. The pulsatility index of graft flow of the left, right ITA and sequential RA grafts with 2 or 3 targets were 1.8±0.7, 2±0.8, 1.9±0.4, and 1.7±0.7, respectively. There was no hospital mortality, and median intensive care unit and hospital stay was 2 and 8 days. Follow-up was completed in 57 patients, but 3 patients refused CTA due to lack of exertional angina. Stenosis of the left, right ITA, and RA grafts occurred in 1/54 (1.9%), 1/21 (4.8%), and 11/120 (9.2%). After a mean of 35.8±10.9 (median: 30.7) months follow-up, there was no late mortality and one documented myocardial infarction was reported. Age, diabetes, previous percutaneous coronary intervention, off-pump technique, RA target number, and graft flow or pulsatility index did not predict RA stenosis. Only RA grafts targeting the circumflex territory had an adverse impact.

Conclusion: The RA of appropriately selected patients can be harvested safely by endoscopic technique and can be used as sequential grafts for CABG with satisfactory outcomes. Intraoperative flow measurement can assure the quality of the grafts. CTA is a valuable tool for patency follow-up.