Improving the Quality of Coronary Bypass Surgery With Intraoperative Angiography: Validation of a New Technique

Desai ND, Miwa S, Kodama D, Cohen G, Christakis GT,Goldman BS,Baerlocher MO,Pelletier MP,Fremes SE. Journal of the American College of Cardiology 2005; 46 (8):1521-25

Reviewer: Hong Liu, MD
UC Davis Health System
Sacramento, CA

Background and Objectives: Technical problems at the site of the distal anastomosis compromise an under appreciated proportion of coronary bypass grafts. The absence of a systematic, validated technique to verify graft patency in the operating room represents a significant breach in quality assurance. Here, the authors report a comprehensive assessment and validation of a new intraoperative angiography technique.

Methods: Fluorescent indocyanine green (ICG) dye is excited with dispersed laser light to create an angiographic depiction of the graft, native vessel, and anastomosis. One-hundred twenty patients underwent ICG angiography. Angiograms were reviewed for reliability and validity studies.

Results: A total of 348 coronary bypass grafts were studied. Each ICG angiogram took 2.2 ± 1.1 min to perform. The ICG angiography found 4.2% of patients had significant graft problems requiring major revision. Quality of visualization was rated according to a seven-point Likert scale (1 = worst, 7 = best). Among conduits, saphenous veins were best visualized (mean score ± standard deviation), 6.4 ± 1.5 versus 5.5 ± 1.9 for internal mammary arteries and 4.4 ± 2.3 for radial arteries (p = 0.02). Location of distal anastomosis did not influence quality of visualization. There was high inter-rater reliability for graft revision (kappa = 1.0) and graft patency (kappa = 0.97) between surgeons. Sensitivity and specificity of the ICG angiograms for graft stenosis > 50% was 100% among 22 grafts also studied with X-ray angiography.

Conclusions: Information from ICG angiograms led to graft revisions for technical problems in 4.2% of patients that would have otherwise gone unrecognized. Intraoperative angiography is an emerging tool for improving the quality of coronary bypass surgery.

Discussion: Graft patency is the major determinant of survival and freedom from repeat intervention after coronary bypass surgery. The construction of a technically perfect anastomosis at the time of surgery is an important determinant of graft patency. Modern coronary bypass series report perioperative graft occlusion rates as high as 11%. Technical errors in bypass graft construction by the operating surgeon are primarily responsible for these early failures. With the exception of coronary artery bypass surgery, virtually all other interventions on the heart, including cardiac valve repair and coronary stenting, are accompanied by completion diagnostic imaging (TEE and coronary angiogram) to ensure an adequate technical result. Despite tremendous improvements in the quality of processes of care in cardiac surgery over the past decade, there is still no well-accepted or broadly used technique to assess the quality of the bypass graft itself. In this study, the authors performed ICG angiogram on 348 coronary bypass grafts in 120 patients. Among them, 4.2% of patients required graft revision. These results are similar to those of other groups who have used different technologies, such as intraoperative X-ray angiography, thermal angiography, Doppler flow measurement, and electromagnetic flow measurement. In all cases, the lesions would have otherwise been missed. For an average coronary bypass case, the total extra time needed to perform intraoperative patency assessment will be eight to 10 minutes. Because ICG angiography is able to identify most graft lesions before chest closure, we think its potential effect on early graft patency may be greater than perioperative aspirin use and anti-lipid medications. Currently, drug-eluting stent therapies for coronary disease provide low single-digit early failure rates, and without high quality intraoperative patency assessment, it is unlikely that the periprocedural failure rates of coronary bypass grafts can remain competitive.

---

Table of Contents:

• President's Message
• SCA Elections (requires Members Section login)


• Literature Reviews
  • Anitricoxideprocessingdefectofredbloodcells created by hypoxia: deficiency of S-nitrosohemoglobin in pulmonary hypertension
  • Improving the Quality of Coronary Bypass Surgery With Intraoperative Angiography: Validation of a New Technique
  • Asymmetric dimethylarginine and the risk of cardiovascular events and death in patients with coronary artery disease
  • Impact of intravenous magnesium on post-cardiothoracic surgery atrial fibrillation and length of hospital stay: a meta-analysis
  • Miniaturized cardiopulmonary bypass in coronary artery bypass surgery: marginal impact on inflammation and coagulation but loss of safety margins


• PRO/CON: Monitoring heart rate variability adds a significant incremental value in cardiovascular surgery
• Pro - Edmundo Pereira de Souza Neto, MD, with Patrice Abry, MD, Jean Frutoso, MD, Patrick Flandrin, MD, Claude Gharib, MD
• Con - Jay Horrow, MD & Dmitri Chamchad, MD

© Society of Cardiovascular Anesthesiologists
Questions or comments? Please send email to webmaster@scahq.org