Quality of Anastomosis in Conventional On-Pump Coronary Artery Bypass Graft Surgery: Influence of the Interrupted Technique Using U-Clips and Correlation with Intraoperative Graft Flow Patterns

Abstract

The interrupted suture technique in creating graft-coronary artery anastomoses in coronary artery bypass graft (CABG) surgery is hypothesized to be superior to the standard continuous technique. However, because of the increased time and knot tying involved with the interrupted technique, the continuous suture became standard. In 2000, the U-clip (a self-closing metal clip) was introduced to help in creating an interrupted anastomosis, although data regarding its clinical use are still somewhat limited. Intraop-erative transit-time flow measurement (TTFM) of blood flow through an anastomosis is frequently used to assess quality of anastomosis creation; mean flow and pulsatile index (PI) are analyzed. PI should typically be between 1 and 5; higher values are associated with errors of anastomosis creation. The current study analyzes the difference in TTFM between U-clips and standard suture in CABG surgery. The study population consists of 30 prospectively enrolled patients undergoing first-time on-pump conventional CABG surgery at St. Anthony Medical Center who were randomized to have their anastomosis created with either U-clips or suture. TTFM were recorded for left internal mammary artery to left anterior descending artery (LIMA-LAD) anastomoses. Of the 30 subjects enrolled (10 women), 12 operations were done with U-clips and 18 with suture. Body mass index (BMI) in the 2 groups was similar. In terms of mean flow, there was no difference between the 2 groups (29.8 +/- 18.4 mL/min for U-clips versus 26.6 +/- 11.0 mL/min for suture, P = .57). In terms of PI, again no difference was found (3.1 +/- 1.3 for U-clips versus 2.5 +/- 0.8 for suture, P = .12). The findings of this study suggest that U-clips are comparable to the standard suture for LIMA-LAD anastomoses in conventional on-pump CABG surgery in terms of intraoperative assessment of graft flow.