Original Article
Arterial Conduits Update

https://doi.org/10.1016/j.hlc.2005.08.009Get rights and content

Arterial grafting for coronary artery disease has been practiced routinely at the Epworth Hospital for 20 years. Bilateral versus single internal thoracic artery grafts is associated with improved survival, which progressively increased over the 20 years of post-surgery. The average increase in survival was 15% at 20 years.

The question of whether to use the radial artery or the saphenous vein graft as supplementary grafts remains unanswered. Current patency data suggest that there is a marginal advantage of radial artery over saphenous graft patency, particularly between 5 and 10 years after surgery. However, there appears to be improved patency of the saphenous vein when used as a coronary artery bypass with the advent of aspirin, lipid-lowering and anti-hypertensive therapy.

Section snippets

Assessment of Graft Patency

Traditionally, assessment of graft patency has depended on re-angiogram for symptoms, using conventional selective coronary angiography. The quality of 32 and 64 multi-detector CT imaging has advanced rapidly, with current resolution being of about 500 μm (0.5 mm). While not as satisfactory as current selective angiography and flat panel screen techniques, which has a 130 μm resolution, the technique is non-invasive; it is rapid, the dose of radiation with modern equipment is slightly less than

Bilateral Internal Thoracic Artery (BITA) Grafts Survival

Meta-analysis of bilateral internal thoracic artery versus single internal thoracic artery (SITA) graft survival was published by Taggart et al.2 The two largest reported series are those of Buxton et al.,3 and Lytle et al.,4 which show a significant reduction in mortality of about 20% following BITA, compared with SITA grafting. The most recent evidence comes from a cohort of 1152 propensity-matched patient pairs from the Cleveland Clinic, followed from a mean survival of 16.5 years, with 50

Internal Thoracic Artery (ITA) Graft Patency

Unadjusted re-angiographic data over 20 years revealed that there was no increase in graft failure, which remained at 5% over the entire 20 years of follow-up.5 Similar results were found for right ITA grafting, although the failure rate was about 10–15% throughout the 20-year period (Fig. 3). The choice of techniques for using the RITA graft has varied. Preference is now given to skeletonisation with mobilisation proximally posterior to the subclavian vein to increase the length. In that way,

The Gastroepiploic Artery (GEA)

The gastroepiploic artery has not been used frequently at Epworth and in the USA, although it is used widely in Japan and to a lesser extent in Europe. The largest series is from Suma et al.7, which showed a 62% graft patency at 120 months using the Kaplan–Meier method, and this is almost certainly higher using the cumulative incidence assessment. The latest figures are from Takahashi, which show excellent graft rates in excess of 80% for the distal right coronary artery to the circumflex

The Radial Artery Graft Patency

Current perspective reveals that the angiographic patency using a Fitzgibbon Grade A is between 80 and 90%, an average follow-up of about 5 years. The largest reported series are those from Tatoulis et al.,8 8420 patients with 369 re-angiograms and 90% early graft patency. The best long-term figures are those of Possati et al.,9 with 91 grafts, all of which were reassessed with an 88% graft patency at a mean follow-up of 8 years. The worst figures are those by the Cardiology Group from the

Randomised Trials of Radial Artery Grafts

Four major studies are in progress; the Radial Artery Patency Study (RAPS),11 the Radial Artery Patency and Clinical Outcomes Study (RAPCO),12 Complete Arterial Revascularisation versus Conventional Coronary Artery Surgery (CARACCASS)13 from Europe, and the Radial Artery versus Saphenous Vein Graft Trial, from Veterans’ Administration in the USA.

A randomized comparison of RA and SV coronary grafts from the RA patency study group was published in the New England Journal of Medicine.14 Four

Recent Information

The benefits of the BITA compared with the SITA grafts continue into the second decade. Arterial graft failure increases three to four times with low-grade stenoses. Because of low number of graft failures using the LITA, this graft should not be discarded in situations in the presence of competitive flow. The ITA grafts remain superior when grafted to the left system compared to the right system. The SV graft is more tolerant to competitive flow than the ITA and when grafted to the right

Recommendations

Use of the bilateral ITA grafts should be considered at all ages. The late results of GEA grafts to the distal right or circumflex are excellent and perhaps more extensive use of the GEA should be explored. Carefully selected and preserved RA or SV grafts should be used as supplementary grafts. At 5 years there appears to be little difference to choose between these two conduits and a longer follow-up would be required to find whether there is a late benefit of RA compared with the SV graft.

The

References (14)

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