Graft Control by Transit Time Flow Measurement and Intraoperative Angiography in Coronary Artery Bypass Surgery

(#2001-2339 ... August 9, 2001)

Per Kristian Hol, MD,¹ Erik Fosse, MD, PhD,¹ Bjørn Erik Mørk, MSc,¹ Runar Lundblad, MD, PhD,² Kjell-Arne Rein, MD, PhD,² Per Snorre Lingaas, MD, PhD,² Odd Geiran, MD, PhD,² Jan Ludvig Svennevig, MD, PhD,² Tor-Inge Tonnessen, MD, PhD,¹ Sigurd Nitter-Hauge, MD, PhD,³ Paulina Due-Tonnessen, MD,⁴ Karleif Vatne, MD,⁴ Hans-Jørgen Smith, MD, PhD⁴

Rikshospitalet, University of Oslo, N-0027 Oslo, Norway, ¹Interventional Centre, ²Department of Thoracic Surgery,³Department of Cardiology, ⁴Department of Radiology

ABSTRACT

Background: The aim of this study was to compare the relationship between intraoperative transit time flow measurements and angiographic findings with long-term graft patency in 72 patients who underwent coronary artery bypass surgery.

Methods: Transit time flow measurements with recording of mean flow and pulsatility indexes were performed after completion of the anastomoses. Coronary angiography was performed on-table while the patients were still in general anesthesia, and then at follow-up three months and 12 months after surgery. Based on angiography, the grafts were graded as type A (fully patent), type B (having more than 50% diameter reduction), or type O (occluded).

Results: Of the 67 left internal mammary artery (LIMA) grafts, 51 (76%) were type A on-table, 14 (21%) were type B, and two (3%) were type O. Of the 57 saphenous vein grafts, 49 (86%) were type A, 7 (12%) were type B, and one (2%) was type O. For both LIMA and vein grafts, there were no differences in flow (p = 0.69 and 0.47, respectively) or pulsatility index (p = 0.79 and 0.83) between type A and B. There were also no differences in flow (p = 0.37 and 0.7) or pulsatility index (p = 0.37 and 0.24) between type B on-table that either normalized or persisted occluded at the follow-up. Transit time flow measurement failed to detect an occluded LIMA graft as shown by intraoperative angiography.

Conclusions: Blood flow measurements performed intraoperatively could not identify significant lesions in arterial or vein grafts, and could not predict graft patency. We have become cautious in interpreting flow measurements alone and combine blood flow recordings with intraoperative angiography in the assessment of graft quality.

AUTHOR/ARTICLE INFORMATION

Submitted August 2, 2001; accepted August 9, 2001.

Address correspondence and reprints requests to: Per Kristian Hol, MD, The Interventional Centre, Rikshospitalet, N-0027 Oslo, Norway, Phone: +4723070100, Fax: +4723070110, E-mail: per.kristian.hol@rikshospitalet.no