Symmetry Bypass Connector Device Linked to Recalcitrant Neointimal Hyperplasia
The recently introduced Symmetry Bypass Connector device seems to be associated with a high rate of acute coronary syndromes within 6 months of coronary artery bypass surgery (CABG), according to an expedited review in the Journal of the American College of Cardiology for January 7.
Additional reports describing high rates of saphenous vein grafts failure led senior author Dr. Sotirios Tsimikas and colleagues to advise close follow-up in patients in whom this device has been implanted and treatment with dual antiplatelet agents for at least 6 months.
In addition, “Strong consideration should be given in restricting its use to cases of unacceptably high risk of stroke during aortic cross-clamping,” they add.
The Symmetry Bypass Connector (St. Jude Medical, St. Paul, Minnesota) was designed to facilitate placement of sutureless aorto-saphenous anastomoses during off-pump CABG, explain the authors, who are based at the University of California-San Diego in La Jolla. The team had placed 320 devices in 121 patients during 263 CABG surgeries. Five patients presented with an acute coronary syndrome within 6 months.
Eleven saphenous vein grafts were either totally occluded or severely compromised, which the team attributes to recalcitrant neointimal hyperplasia. Follow-up procedures in four patients “revealed highly recalcitrant lesions requiring high-pressure inflations with noncompliant or cutting balloons and adjunctive stenting due to recoil,” they note. Restenosis or occlusions developed in two, and one patient even failed brachytherapy.
Dr. Tsimikas’ team points out that since their paper was submitted, two additional studies and an abstract presentation revealed similar high rates of short-term failure. “Up to 10% of patients develop clinical symptoms and up to 38% may have evidence of some extent of angiographic stenosis in the first six months following CABG,” they write.
In addition to antiplatelet treatment, the authors advise evaluation for myocardial ischemia at 2 to 6 months and “a low threshold in performing coronary angiography,” since “anastomotic device stenosis may become a significant new disease entity in patients undergoing CABG with such devices.”
J Am Coll Cardiol 2004;42:133-139.
