Interrupted nitinol U-Clips versus standard running suture for the central arterial T-graft anastomosis: a prospective randomized study.

Objectives: Studies carried out to date suggest that the interrupted suture technique using U-Clips for anastomoses in coronary surgery may be superior to the standard running polypropylene suture. The purpose of this study was to compare safety and effectiveness of a central T-graft anastomosis constructed with the left internal thoracic artery (LITA) in situ (to the left anterior descending (LAD)) in which the free right internal thoracic artery (to the circumflex branch of the right coronary artery (RCX)) was implanted (RITA-to-LITA) using either self-closing nitinol U-Clips or simple continuous suture. We hypothesized that internal thoracic arteries could adapt their diameter to the blood flow.

Methods: Thirty patients underwent total arterial revascularization using a T-graft constructed with free LITA in situ to LAD in which the free RITA to the circumflex artery was implanted (central T-graft anastomosis). In all cases, free RITA was used as a sequential graft with two peripheral anastomoses. Patients were randomly assigned to two groups: in group A (n=15), central T-graft anastomosis was performed using a standard 8/0 polypropylene running suture. In group B (n=15), central T-graft anastomosis was performed using U-Clips. Intra-operative transit time flow measurements were recorded. Patency control was performed in 30 patients 2 weeks and 6 months postoperatively, using 64-slice computed tomography (CT) angiography. The diameter of the LITA was measured proximal and distal and the diameter of the RITA distal to the central T-graft anastomosis.

Results: Perioperative results were similar in the two groups (P=ns). Intra-operative transit time flow measurement showed patent grafts in all patients. There were no hospital deaths. Two weeks postoperatively, all grafts were patent. At 6-month follow-up, one RITA and one LITA (both in group B) were closed distal to the central T-graft anastomosis. There was no death and no re-intervention during follow-up. Statistical analysis showed no significant changes in graft diameters after 2 weeks and 6 months in both groups.

Conclusions: The U-Clip anastomosis technique is in our experience safe but not superior to the standard running suture using polypropylene material. Remodeling of the ITA grafts close to the central T-graft anastomosis was neither observed for the standard running suture nor for the U-Clip anastomoses.