title: Pilot study of cryoplasty with use of PolarCath peripheral balloon catheter system for dialysis access.
abstract: OBJECTIVE
  To evaluate the safety and feasibility of cryoplasty as the initial balloon treatment for dialysis access venous stenoses.
  
  
  METHODS
  Twenty patients with grafts (n = 18) or arteriovenous fistulas (n = 2) were enrolled in an institutional review board-approved prospective study. Patients with high venous dialysis pressures (n = 7), poor flow (n = 3), abnormal thrill (n = 3), nonmaturation (n = 2), poor clearance (n = 2), edema (n = 1), prolonged bleeding (n = 1), or recurrent clotting (n = 1) in the presence of stenoses >/=50% were eligible. Mean stenosis measurement was 62.8% (range, 51%-82%). Mean lesion length was 2.57 cm (range, 0.4-5.7 cm). Device success required complete cryoplasty balloon expansion. Procedure success required anatomic success combined with a clinical or hemodynamic indicator of success. Primary circuit patency ended with any restenosis. Primary lesion patency ended with index lesion restenosis.
  
  
  RESULTS
  The device success rate was 53% (nine of 17). The anatomic success rate after cryoplasty was 35% (seven of 20). Eighty percent of lesions (16 of 20) were treated with conventional percutaneous transluminal angioplasty (PTA) balloons after cryoplasty. The procedure success rate after supplemental PTA was 80% (16 of 20). The primary circuit patency rates were 82% (14 of 17) at 3 months and 19% (three of 16) at 6 months. The primary lesion patency rates were 88% (15 of 17) at 3 months and 25% (four of 16) at 6 months. All patients reported pain during cryoplasty, and the 16 who underwent supplemental PTA described cryoplasty as more painful than PTA. Cryoplasty-related complications included one case of transient spasm.
  
  
  CONCLUSIONS
  Use of the PolarCath peripheral balloon catheter system as the initial balloon for dialysis access venous stenoses is safe but painful. Anatomic success rates after cryoplasty are low. Results of cryoplasty supplemented by PTA appear comparable to those of PTA alone.
authors.affiliation: Department of Radiology, Georgetown University School of Medicine, Washington Hospital Center, 110 Irving Street Northwest, Washington, DC 20010, USA. rgray@aacllc.com
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Gray
authors.forename: Jay D
authors.initials: JD
authors.lastname: Varma
authors.forename: Sung S
authors.initials: SS
authors.lastname: Cho
authors.forename: Lisa C
authors.initials: LC
authors.lastname: Brown
mesh_terms: D002404:Catheterization / Q000295:instrumentation* / Q000379:methods*; D003452:Cryosurgery / Q000295:instrumentation* / Q000379:methods*; D003956:Dialysis / Q000009:adverse effects*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D010865:Pilot Projects; D016896:Treatment Outcome; D014689:Venous Insufficiency / Q000209:etiology* / Q000601:surgery*