Cryoballoon Angioplasty Cut Stent Use

By Mitchel L. Zoler

PHILADELPHIA -- Using a cryoballoon for primary angioplasty of the superficial femoral artery cut the need for adjunctive stenting in a series of 282 patients., according to Dr. Andrew M. Bakken at the Vascular Annual Meeting, sponsored by the Society for Vascular Surgery.

By cooling the interior endothelial surface of the superficial femoral artery (SFA) to -10° C, a cryoballoon is believed to drop the incidence of reocclusion following angioplasty by lowering the potential for neointimal and collagen formation, and by producing a more uniform dilatation of the SFA wall leading to less elastic recoil, said Dr. Bakken, of the department of surgery at the University of Rochester (N.Y.).

He and his associates reviewed outcomes of procedures on 313 limbs at the university hospital during 1999-2005. About two-thirds were done using conventional, high-pressure balloon angioplasty alone; the remaining dilations were done with a cryoballoon made by Boston Scientific Corp. Several of Dr. Bakken's associates in the study serve on Boston Scientific's advisory board. Patients were not randomized, though the cryoballoon and plain angioplasty groups were closely matched in clinical characteristics.

During the procedures, 75% of the patients treated with angioplasty alone required at least one adjunctive stent, compared with 22% of patients treated with the cryoballoon, a statistically significant difference. All other measured outcomes were similar in the two groups, including vessel patency out to 1 year of follow-up. Stenting was done at the discretion of the operator, usually for either of two reasons: The SFA had a 30% or greater residual stenosis following angioplasty, or the artery had a severe, flow-limiting dissection.

Treatment with a cryoballoon might be especially useful for avoiding adjunctive stents in patients with more complex lesions, those rated TASC C or D, Dr. Bakken said

When asked to comment, Dr. Edward Woo, assistant professor of surgery, Hospital of the University of Pennsylvania, Philadelphia, stated: "Cryoballoon angioplasty is a novel interventional tool for management of the SFA occlusive disease.

"The purported mechanism is induced apoptosis or death of the cells which would normally lead to intimal hyperplasia. In the last couple of years, endovascular specialists have been presented with an array of newer therapies designed to augment the success of angioplasty alone. Durability remains the unanswered question.

"Although the results presented herein are very promising, this study is somewhat limited by its design. Ultimately, a randomized prospective study would be best for determining the utility of cryoplasty," he concluded.