circumferential aorto-coronary bypass markers revisited

Editorial Comment

Circumferential Aorto-CoronaryBypass Markers Revisited

David A. Clark, MD

Stanford University School of MedicineStanford, California

In the March 1997 issue of this journal, Eisenhauer et al.explored the benefits of circumferential aorto-coronary bypassgraft markers and presented a compelling argument for their use[1]. The striking benefit during post-operative angiography in termsof a 30% reduction in fluoroscopy time, which has an obviousimpact on radiation exposure for the patient, physician, and cath labtechnical staff, was well demonstrated. This also translates to amarkedly reduced procedural time, which benefits the hospital interms of personnel salaries, a most important factor in this time offinancial cutbacks. The shorter procedural time also benefits the patientby decreasing the ‘‘flat on the back’’ time in the catheterization suite.

In addition, the 22% reduction in contrast volume in ‘‘marked’’versus ‘‘unmarked’’ cases has not only a significant economicimpact, but also a positive effect for the patient in terms of renalsafety. The 17% reduction in the number of angiographic cathetersneeded to find the grafts also has a potentially significant economicimpact.

When this article and my editorial comment on the subject werepublished in March, I determinedly made copies of both andpresented them to several surgeons with whom I have had anongoing debate regarding marker use. Amazingly, some of themstill held out for the possibility that the placement of circumferen-tial markers on grafts might adversely affect graft patency. Thiscurrent article should dispel that notion, although I am sure that thespecter of a prospective randomized study (thought to be so muchgarbage by surgeons in the early days of bypass surgery, and astudy already promised by Eisenhauer et al.) will be used as the lastargument by proponents of markerless surgery.

The current article [2] has appropriate selection criteria, num-bers, a control group, and the analysis of post-operative sequence toonce and for all dispel the notion that graft markers may cause graftclosure. Indeed, the overall patency rate of 71.1% in ‘‘marked’’grafts versus 50% in ‘‘unmarked’’ grafts shows that the use ofmarkers has a positive effect on graft patencyrates (if not graft

patency itself). At least, the use of circumferential graft markers hasnot had deliterious effects on the long-term patency of the graft somarked.

It is noteworthy that grafts were considered occluded if no flowcould be demonstrated either by selective injection into the stumpof an occluded graft or ascending aortography, which was mostcertainly undertaken after a long and fruitless search for unmarkedgrafts. This generous definition of patency should satisfy anycriterion for diligent demonstration of graft patency.

The improvement in graft patency in marked versus unmarkedgrafts was consistent in each measured time interval of elapsedtime since bypass surgery. The authors suggest that the lowerpatency rates in some groups may be due to the use of internalmammary bypasses to ‘‘choice’’ recipient vessels with veins beingrelegated to less desirable arteries. They suggest other factors aswell, but it would seem that the similarity of the ‘‘marked’’ andcontrol populations would obviate any anatomic or age groupprejudices and place the difference squarely on surgeon preference.Some of the numbers are quite dramatic, such as 90% patency inmarked versus 47% patency in unmarked grafts in those patientsstudied within a year of surgery and 80% versus 60% in thosestudied within five years of surgery. Dare we suggest that the bettersurgeons are using circumferential markers on their grafts?

This article, combined with previous studies without a controlgroup that reported an 84% patency rate in marked grafts [3],should, for all intents and purposes, end the debate. The plannedprospective randomized study may be interesting, but the previ-ously demonstrated advantages of placing circumferential markersor grafts coupled with this study showing no deleterious effect ongraft patency should convince any good surgeon to use them.

REFERENCES

1. Eisenhauer MD, Collier HE, Eisenhauer TL, Cambier PA: Benefi-cial impact of aorto-coronary graft markers on post-operativeangiography. Cathet Cardiovasc Diagn 40:249–253, 1997.

2. Eisenhauer MD, Malik JA, Coyle LC, Arendt MA: Impact ofaortocoronary graft markers on subsequent graft patency: A retro-spective review. Cathet Cardiovasc Diagn 42:259–261, 1997.

3. Halseth WL, Elliot DP, Walker EL, Meza F: Angiographic restudyof coronary artery bypass grafts simplified by a marker. Clin Cardiol1:169–172, 1978.

Catheterization and Cardiovascular Diagnosis 42:262 (1997)

r 1997 Wiley-Liss, Inc.