Letter to the Editor: Intraoperative Graft Patency Verification and Postoperative Angiography: A Word of Caution

(#2001-01099)

Giuseppe D'Ancona, MD, François Dagenais, MD, Daniel Doyle, MD.

Department of Cardiac Surgery of the Hospital Laval, Ste Foy, Quebec, Canada

EXCERPT

We have read with interest Dr. Hol's report [Hol 2001] about graft control by transit time flow measurement (TTFM) and intraoperative angiography. Although we congratulate the authors for their timely manuscript, we believe that some clarifications about intraoperative TTFM should be given.

The authors describe their experience with testing intraoperative graft patency via TTFM in a group of 72 patients. A total of 67 left internal mammary arteries (LIMA) and 57 saphenous vein grafts (SVG) were tested intraoperatively. At chest closure all the grafts were reevaluated, in the operating room, with angiography. Based on angiography, the grafts were graded as type A (fully patent), type B (more than 50% diameter reduction), or type O (occluded). Out of the 67 LIMA grafts, 51 were classified as type A, 14 as type B, and 2 as type O. No significant differences in intraoperative flow measurement and pulsitility index (PI) were found between type A and type B LIMA grafts. Interestingly, 7 of the 14 type B LIMA grafts normalized their pattern at a follow-up angiographic study. When considering the 57 SVGs, 49 were classified as type A, 7 as type B, and 1 as type O. No differences in flow values and PI values were noticed between the type A and B SVGs. Five of the seven type B SVGs normalized their pattern at a follow-up angiographic study. The authors conclude that TTFM can not correctly predict intraoperative graft patency and TTFM findings should be addressed cautiously.

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