title: Comparative evaluation of stretch and non-stretch polytetrafluorethylene (PTFE) prosthetic grafts for femoro-popliteal bypass.
abstract: BACKGROUND
  The results of femoropopliteal bypass surgery using various prosthetic materials are frustrated until the expanded polytetrafluorethylene (PTFE) was introduced as a vascular prosthesis in 1973. Since then, the techniques of femoropopliteal bypass improved rapidly, but the long-term patency rate, compaired with autogenous saphenous vein graft, remained unsatisfied. The stretch PTFE graft developed in 1991 became available for clinical usage. The objective of this study is to compare the long-term results between stretch and non-stretch PTFE prosthetic conduits in patients who underwent femoropopliteal vascular reconstruction.
  
  
  METHODS
  From Jun. 1993 to Jun. 1998,68 femoropopliteal bypass operations were performed in 59 patients between stretch and non-stretch PTFE conduits. The stretch PTFE group included 34 patients, 40 surgery (above knee 22, below knee 18). The non-stretch PTFE group included 25 patients, 28 surgery (above knee 17, below knee 11). The patency of grafts was followed by Doppler segmental pressure for at least 2 years. The indication for the bypass grafting operation was disabling claudication and critical ischemia. Patients were observed every 3 months for the first year and every 6 months thereafter. All patients were instructed to take aspirin (100 mg) daily in the whole period of study. Doppler-derived ankle-brachial indices (ABIs) were determined preoperatively and serially postoperatively. A bypass graft was considered to be patent when the Doppler-derived postoperative ABI remained significantly improved (more than 0.15 units higher than their preoperative value). Patency rates were compared by using the Kaplan-Meier life table analysis.
  
  
  RESULTS
  Reconstructions above knee had significantly different patency rates (83% vs 66%, p < 0.05): the stretch PTFE group had more acceptable clinical result than the non-stretch PTFE group. Below-knee bypass made no significantly different results between groups, (59% vs 53%, p > 0.10).
  
  
  CONCLUSIONS
  The stretch PTFE stretches farer and makes better long-term patency for femoropopliteal bypass. We suggested that the stretch PTFE prosthetic conduits is a reasonable alternative for the above knee popliteal artery lesions and reserved for patients lacking autogenous tissues for below knee artery reconstruction.
authors.affiliation: Department of Surgery, Taipei Veterans General Hospital, National Yang-Ming University School of Medicine, Taiwan, ROC.
authors.forename: Chorng-Horng
authors.initials: CH
authors.lastname: Lu
authors.forename: Jason
authors.initials: J
authors.lastname: Chang
authors.forename: Shiau-Ting
authors.initials: ST
authors.lastname: Lai
authors.forename: Chun-Che
authors.initials: CC
authors.lastname: Shih
mesh_terms: D000368:Aged; D001807:Blood Vessel Prosthesis; D005260:Female; D005263:Femoral Artery / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011138:Polytetrafluoroethylene; D011150:Popliteal Artery / Q000601:surgery*
chemical_list: D011138:Polytetrafluoroethylene