title: Pilot trial of cryoplasty or conventional balloon post-dilation of nitinol stents for revascularization of peripheral arterial segments: the COBRA trial.
abstract: OBJECTIVE
  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).
authors.affiliation: University of Texas Southwestern Medical Center, Dallas, Texas, USA. subhash.banerjee@utsouthwestern.edu
authors.forename: Subhash
authors.initials: S
authors.lastname: Banerjee
authors.forename: Tony S
authors.initials: TS
authors.lastname: Das
authors.forename: Mazen S
authors.initials: MS
authors.lastname: Abu-Fadel
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Dippel
authors.forename: Nicolas W
authors.initials: NW
authors.lastname: Shammas
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Tran
authors.forename: Ahmad
authors.initials: A
authors.lastname: Zankar
authors.forename: Cyril
authors.initials: C
authors.lastname: Varghese
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Kelly
authors.forename: Rick A
authors.initials: RA
authors.lastname: Weideman
authors.forename: Bertis B
authors.initials: BB
authors.lastname: Little
authors.forename: Robert F
authors.initials: RF
authors.lastname: Reilly
authors.forename: Tayo
authors.initials: T
authors.lastname: Addo
authors.forename: Emmanouil S
authors.initials: ES
authors.lastname: Brilakis
mesh_terms: D000368:Aged; D000497:Alloys; D000800:Angioplasty, Balloon / Q000379:methods*; D003452:Cryosurgery / Q000379:methods*; D005260:Female; D005263:Femoral Artery; D005500:Follow-Up Studies; D006801:Humans; D007383:Intermittent Claudication / Q000000981:diagnostic imaging / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D011474:Prosthesis Design; D019651:Plastic Surgery Procedures / Q000379:methods*; D015607:Stents; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color
chemical_list: D000497:Alloys; C013616:nitinol