title: The effect of a venous anastomosis Tyrell vein collar on the primary patency of arteriovenous grafts in patients undergoing hemodialysis.
abstract: OBJECTIVE
  Vein collars and patches are used at the distal anastomoses of infrainguinal prosthetic grafts to improve graft patency. We initiated a randomized, prospective study to determine whether a Tyrell vein collar at the venous anastomosis of forearm loop arteriovenous grafts (AVGs) would improve patency.
  
  
  METHODS
  Patients who required new forearm AVGs were randomized to (1) a standard end-to-side graft-vein anastomosis (control group) or (2) a Tyrell vein collar between the graft and the vein (study group). End points were (1) graft thrombosis, (2) graft removal and ligation, or (3) inadequate graft function. Randomization of 75 subjects was planned. The study was terminated early for ethical reasons.
  
  
  RESULTS
  Seventeen patients (eight men, nine women) with a mean age of 52.8 years (range, 31-79 years) had 17 grafts placed (control group, n = 10; study group, n = 7). Comorbidities were not different between the groups (P>.05). Six (86%) of seven study grafts failed by 9 months (mean, 4.6 months). Four (66%) failed study grafts had venous outflow tract stenosis from intimal hyperplasia. This was confirmed at surgery in three and by angiography in one. The 9-month primary patency was 80% for the control group versus 17% for the study group (P =.015). Smaller outflow vein diameter in the study group (P =. 048) did not account for this inferior graft patency.
  
  
  CONCLUSIONS
  A Tyrell vein collar at the venous anastomosis of a forearm AVG resulted in premature graft failure. The use of a Tyrell vein collar may accelerate venous anastomosis intimal hyperplasia.
authors: Division of Vascular Surgery, Naval Medical Center, USA. paul.gagne@med.nyu.edu
authors: P J
authors: PJ
authors: Gagne
authors: J
authors: J
authors: Martinez
authors: R
authors: R
authors: DeMassi
authors: R
authors: R
authors: Gregory
authors: F N
authors: FN
authors: Parent
authors: R
authors: R
authors: Gayle
authors: G H
authors: GH
authors: Meier
authors: C
authors: C
authors: Philput
mesh_terms: D000328:Adult; D000368:Aged; D001166:Arteriovenous Shunt, Surgical / Q000379:methods*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia; D008297:Male; D008875:Middle Aged; D011138:Polytetrafluoroethylene; D011446:Prospective Studies; D006435:Renal Dialysis; D012307:Risk Factors; D013997:Time Factors; D017539:Tunica Intima / Q000473:pathology; D014654:Vascular Patency; D014680:Veins / Q000637:transplantation*
chemical_list: D011138:Polytetrafluoroethylene