Twenty-year experience with off-pump coronary artery bypass grafting and early postoperative angiography

Abstract: Objective
Background: We have performed off-pump coronary artery bypass grafting (off-pump CABG; OPCAB) and also performed early postoperative angiography to assess anastomosis accuracy and patency in most of our patients requiring surgical revascularization.

Methods
Of 3083 patients who underwent isolated CABG between 1998 and 2017, 2919 patients (94.7%) underwent OPCAB. Conduits for distal anastomoses were left internal thoracic artery (ITA;n=2764), right ITA (n=866), right gastroepiploic artery (n=997), radial artery (n=16), and saphenous vein (n=1505). Since the introduction of transit-time flow measurement (TTFM) in 2000, we revised abnormal grafts intraoperatively. Early (≤7days) angiography was performed in 2820 patients (96.6%) at 1.5±1.2 postoperative days, and surgical intervention was performed based on angiographic findings.

Results
Operative mortality was 1.1% (32/2919). Average number of distal anastomoses was 3.2±1.0. Intraoperative flowmetry-guided revision for distal anastomosis failures was performed in 109 of 8,585 distal anastomoses (1.3%). Angiography showed an overall patency of 98.2% (8836/9001); 99.0% (5484/5540) for arterial and 96.9% (3352/3461) for venous conduits (P<0.0001). Patency of venous conduits was 87.2% (231/265) for free grafts and 97.7% (3121/3196) for composite grafts (P=0.0011). After the introduction of TTFM, patency of arterial conduits became significantly higher (97.2% vs 99.2%; P=0.0375); however, patency of free venous grafts was not significantly improved (86.0% vs 91.4%, P=0.1812). Early re-intervention according to angiographic findings was performed in 76 patients (2.7%). Re-evaluation of graft patency before discharge in 31 who underwent revision of distal anastomoses showed improved patency (65.1% [56/86] vs 95.3% [82/86]; P<0.001).

Conclusions
Intraoperative flowmetry and revision of abnormal grafts improved early arterial graft patency, and reoperation based on early angiographic findings may further improve graft patency at the time of discharge.