Radial-Artery or Saphenous-Vein Grafts in Coronary-Artery Bypass Surgery
The authors performed a patient-level meta-analysis of six randomized trials comparing left internal mammary artery (LIMA) + saphenous vein graft (SVG) versus LIMA + radial artery graft. In a total of more than 1000 patients and at a follow-up of 60 months, the incidence of adverse cardiac events (death, myocardial infarction, or repeat revascularization) was significantly lower in patients with a radial artery graft as compared with those in the SVG group (hazard ratio, 0.67; 95% confidence interval, 0.49 – 0.90; p = 0.01). Moreover, the patency rate at 50 months of angiographic follow-up was higher in the LIMA + radial artery group. These results emphasize the importance of using more arterial grafts.
All reliable studies using radial arteries as CABG conduits have shown increased patency over saphenous vein grafts. The limitation of this study, as so many others, is the limited five year follow-up. We know that 50% of SVGs are severely diseased at 10 years, and 95% of IMAs are open at 20 years. Radial arteriy patency will likely fall in between. Does anyone have reliable data on the long term patency (15-20 yrs) on radial arteries?
Indeed a landmark trial. We have been using the radial artery since 1995 and now use one RA in 70% cases along with at least 1 IMA and bilateral RA in 33% cases . We have a limited angiographic followup – but it shows an 85% patency at 5 years . Results will be good if the following criteria are followed :
1. No touch technique of harvesting. Liberal use of papaverine solution
2. IV Diltiazem intraop and early postop. Oral CCB post op
3. No RA stenosis, plaque or calcification as seen by Doppler ultrasonography
5. No Diffuse calcification noted during harvesting
6. Diameter > 2 mm
7. Not to be used for at least 3 months following a trans RA CAG – check always with Duplex scan in such cases and in elderly
8. More than 80% stenosis in target artery
The proximal anastomosis can be done to the aorta or to the IMA .
We have found the RA to be a rather forgiving conduit and easy to harvest . Complications (nerve damage, ischemia) are extremely rare .
This trial encourages us to be more liberal with the RA use where indicated . The 10 year results will be interesting