Use of nitinol-U clips and flow characteristics of LIMA-LAD anastomoses

The aim of this study was to compare flow characteristics of LIMA-LAD anastomoses constructed using two different techniques. Thirty patients underwent MIDCAB using either simple continuous suture (20) or separate nitinol U-clips (10). Intraoperative transit time flow measurements were recorded. Preoperative variables were similar in the two groups. Anastomosis time was significantly higher in the U-clipped group (9.9+/-1.5 min. vs. 11.4+/-1.5 min; P=0.016). Average flow value in the 20 continuous suture LIMA-LAD anastomoses was 26.7+/-8.8 ml/min versus 36.3+/-10.6 ml/min in the 10 U-clipped grafts (P=0.014). Pulsatility Index value was significantly lower in the U-clipped group (3.1+/-0.9 vs. 1.8+/-0.3, P=0.0001) and diastolic flow index was significantly higher (0.7+/-0.04 vs. 0.8+/-0.03, P=0.046). Perioperative results were similar in the two groups (P=ns). No mortality was reported. Postoperative trans-thoracic Doppler confirmed patency of the LIMA in all 30 patients. At short-term clinical follow-up (60+/-4 days), all patients were in CCSI. Nitinol U-clips can be used to construct LIMA-LAD anastomoses on the beating heart. Flow dynamics of these anastomoses are superior to those of grafts constructed using continuous suture technique. Particularly, total flow is higher and diastolic flow may reach values of 80% of the total measured flow.