title: Potential benefits from heating the high-dose rtPA boluses used in catheter-directed thrombolysis for acute/subacute lower limb ischemia.
abstract: OBJECTIVE
  To explore the potential benefits from heating recombinant tissue plasminogen activator (rtPA) before catheter-directed thrombolysis in patients with lower-limb ischemia of <30 days' duration.
  
  
  METHODS
  Over a 2-year period, 34 patients (26 men; mean age 63.5 years, range 39-80) with 10 iliac and 24 infrainguinal arterial occlusions (5 embolic and 29 thrombotic) were treated with two 5-mg boluses of rtPA injected into the proximal clot, followed by 2 additional 5-mg boluses of rtPA. In the first 18 patients (group A), room temperature rtPA was administered, whereas in the last 16 patients (group B), the rtPA boluses were heated to 38 degrees C for 30 minutes before injection. Residual thrombus was treated with a continuous infusion of 2.5 mg/h of rtPA for 4 hours then at a reduced dose (1 mg/h).
  
  
  RESULTS
  Successful thrombolysis was achieved in 28 (82%) arteries. Unmasked lesions were treated with balloon angioplasty/stenting in 17 cases and with surgery in 4. One fatal retroperitoneal hematoma occurred in group A. Heating the rtPA did not significantly alter the outcome of thrombolysis. However, a statistically significant reduction in the total rtPA dose was observed in group B (24.28 mg versus 27.9 mg in group A, p=0.05), as well as quicker lysis (2 hours, 42 minutes versus 6 hours, 12 minutes in group A, p=0.001). There was no statistical difference in the amputation-free survival at 30 days between the groups.
  
  
  CONCLUSIONS
  In patients with acute or subacute lower limb ischemia treated with catheter-directed thrombolysis, heating the rtPA results in faster lysis with a considerable reduction in the total dose of the lytic agent.
authors.affiliation: Department of Radiology, University Hospital of Heraklion, Medical School of Heraklion, Crete, Greece. tsetis@med.uoc.gr
authors.forename: Dimitrios K
authors.initials: DK
authors.lastname: Tsetis
authors.forename: Asterios N
authors.initials: AN
authors.lastname: Katsamouris
authors.forename: Athanasios D
authors.initials: AD
authors.lastname: Giannoukas
authors.forename: Adam A
authors.initials: AA
authors.lastname: Hatzidakis
authors.forename: Theodoros
authors.initials: T
authors.lastname: Kostas
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Chamalakis
authors.forename: Christos
authors.initials: C
authors.lastname: Ioannou
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Gourtsoyiannis
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000188:drug therapy* / Q000628:therapy; D016009:Chi-Square Distribution; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007511:Ischemia / Q000188:drug therapy*; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011994:Recombinant Proteins / Q000008:administration & dosage; D018709:Statistics, Nonparametric; D015912:Thrombolytic Therapy / Q000379:methods*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator