title: Thrombolysis or peripheral arterial surgery: phase I results. TOPAS Investigators.
abstract: OBJECTIVE
  Thrombolytic therapy is widely used in the treatment of peripheral arterial occlusion, but prospective, randomized comparisons with standard therapy remain few. A multicenter trial of thrombolysis or peripheral arterial surgery (TOPAS) was organized to compare critically the use of recombinant urokinase (rUK) or surgery for the initial treatment of acute lower-extremity ischemia. Phase I of the trial was designed as a dose-ranging trial to evaluate the safety and efficacy of three doses of rUK in comparison with surgery.
  
  
  METHODS
  In a multicenter, prospective, double-blind comparison, 213 patients who had acute lower-extremity ischemia for 14 days or fewer were randomized to one of two groups. The first group received one of three dosages of rUK (catheter-directed at 2000, 4000, or 6000 IU/min for 4 hours, then 2000 IU/min to a maximum of 48 hours). The second group underwent surgery. Successful thrombolysis was followed by surgical or endovascular interventions when anatomic lesions responsible for the occlusion were unmasked. Patients were followed-up for 1 year; data were evaluated on an intent-to-treat basis.
  
  
  RESULTS
  The 4000 IU/min rUK dosage was chosen as the most appropriate thrombolytic regimen because it maximized lytic efficacy against the risk of bleeding. Complete (> 95%) lysis of thrombus was achieved in 71% of the 49 patients who were randomized to the 4000 IU/min group, with a mean infusion time of 23 hours. In contrast, complete lysis was achieved in 67% of patients who received 2000 IU/min and in 60% of patients who received 6000 IU/min. Hemorrhagic complications occurred in 2% of the 4000 IU/min group versus 13% of the 2000 IU/min group (p = 0.05) and 16% of the 6000 IU/min group (p = 0.03). In a comparison of the 4000 IU/min group with the surgical group, the 1-year mortality rate (14% vs 16%) or amputation-free survival rate (75% vs 65%) did not differ significantly. The frequency and magnitude of surgery in the patients randomized to rUK were decreased (p < 0.001).
  
  
  CONCLUSIONS
  The preliminary results suggest that an initial rUK dose of 4000 IU/min is safe and efficacious in the treatment of acute lower-extremity ischemia. rUK therapy is associated with limb salvage and patient survival rates similar to those achieved with surgery, concurrent with a reduced requirement for complex surgery after thrombolytic intervention.
authors.affiliation: Department of Surgery, University of Rochester, NY 14642, USA.
authors.forename: K
authors.initials: K
authors.lastname: Ouriel
authors.forename: F J
authors.initials: FJ
authors.lastname: Veith
authors.forename: A A
authors.initials: AA
authors.lastname: Sasahara
mesh_terms: D000208:Acute Disease; D000368:Aged; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007511:Ischemia / Q000097:blood / Q000188:drug therapy / Q000601:surgery; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000097:blood / Q000188:drug therapy* / Q000601:surgery*; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000009:adverse effects; D015912:Thrombolytic Therapy / Q000009:adverse effects / Q000706:statistics & numerical data; D014568:Urokinase-Type Plasminogen Activator / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D011994:Recombinant Proteins; D014568:Urokinase-Type Plasminogen Activator