Pilot trial of cryoplasty or conventional balloon post-dilation of nitinol stents for revascularization of peripheral arterial segments: The COBRA trial

Subhash Banerjee, Tony S. Das, Mazen S. Abu-Fadel, Eric J. Dippel, Nicolas W. Shammas, Daniel L. Tran, Ahmad Zankar, Cyril Varghese, Kevin C. Kelly, Rick A. Weideman, Bertis B. Little, Robert F. Reilly, Tayo Addo, Emmanouil S. Brilakis

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


Objectives: The purpose of this study is to compare post-dilation strategies of nitinol self-expanding stents implanted in the superficial femoral artery of diabetic patients with peripheral arterial disease. Background: Endovascular treatment of superficial femoral artery disease with nitinol self-expanding stents is associated with high rates of in-stent restenosis in patients with diabetes mellitus. Methods: We conducted a prospective, multicenter, randomized, controlled clinical trial of diabetic patients to investigate whether post-dilation of superficial femoral artery nitinol self-expanding stents using a cryoplasty balloon reduces restenosis compared to a conventional balloon. Inclusion criteria included diabetes mellitus, symptomatic peripheral arterial disease, and superficial femoral artery lesions requiring implantation of stents >5 mm in diameter and >60 mm in length. Primary endpoint was binary restenosis at 12 months, defined as <2.5-fold increase in peak systolic velocity by duplex ultrasonography. Results: Seventy-four patients, with 90 stented superficial femoral artery lesions, were randomly assigned to post-dilation using cryoplasty (n = 45 lesions) or conventional balloons (n = 45 lesions). Mean lesion length was 148 ± 98 mm, mean stented length was 190 ± 116 mm, mean stent diameter was 6.1 ± 0.4 mm, and 50% of the lesions were total occlusions. Post-dilation balloon diameters were 5.23 ± 0.51 mm versus 5.51 ± 0.72 mm in the cryoplasty and conventional balloon angioplasty groups, respectively (p = 0.02). At 12 months, binary restenosis was significantly lower in the cryoplasty group (29.3% vs. 55.8%, p = 0.01; odds ratio: 0.36, 95% confidence interval: 0.15 to 0.89). Conclusions: Among diabetic patients undergoing implantation of nitinol self-expanding stents in the superficial femoral artery, post-dilation with cryoplasty balloon reduced binary restenosis compared to conventional balloon angioplasty. (Study Comparing Two Methods of Expanding Stents Placed in Legs of Diabetics With Peripheral Vascular Disease [COBRA]; NCT00827853)

Original languageEnglish (US)
Pages (from-to)1352-1359
Number of pages8
JournalJournal of the American College of Cardiology
Issue number15
StatePublished - Oct 9 2012


  • cryoplasty
  • diabetes mellitus
  • peripheral arterial disease
  • superficial femoral artery

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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