No abstract

To estimate the patency results of percutaneous transluminal angioplasty and bypass surgery in the treatment of femoropopliteal arterial disease, a Medlars search of the English-language medical literature was performed. Inclusion required that studies 1) report original data, 2) report patency with a life table or Kaplan-Meier analysis with the number at risk or standard errors, 3) define patency as hemodynamic improvement, 4) report the distribution of covariates, and 5) not duplicate other published material. Using a method based on the proportional-hazards model and the actuarial life-table approach, the results were adjusted for differences in case-mix of the study populations and patency was predicted for subgroups at various levels of risk for failure. The unadjusted pooled life tables yielded five-year patencies of 45% (+/- 2%) for angioplasty, 73% (+/- 2%) for bypass surgery using a vein graft, and 49% (+/- 3%) for bypass surgery using a polytetrafluoroethylene graft. Adjusted five-year primary patencies after angioplasty varied from 12% to 68%, the best results being for patients with claudication and stenotic lesions. Adjusted five-year primary patencies after surgery varied from 33% to 80%, the best results being for saphenous vein bypass performed for claudication. The authors conclude that pooling life-table data without adjustment for covariates can be misleading. Indication, lesion type, vein graft availability, and site of the distal graft anastomosis need to be considered in predicting patency results of revascularization for femoropopliteal arterial disease.

No abstract

Thrombolysis of acute pulmonary embolism can be accomplished more rapidly and safely with 100 mg of recombinant human tissue-type plasminogen activator (rt-PA) (Activase) than with a conventional dose of urokinase (Abbokinase) given as a 4,400-U/kg bolus dose, followed by 4,400 U/kg per h for 24 h. To determine the effects of a more concentrated urokinase dose administered over a shorter time course, this trial enrolled 90 patients with baseline perfusion lung scans and angiographically documented pulmonary embolism. They were randomized to receive either 100 mg/2 h of rt-PA or a novel dosing regimen of urokinase: 3 million U/2 h with the initial 1 million U given as a bolus injection over 10 min. Both drugs were delivered through a peripheral vein. To assess efficacy after initiation of therapy, repeat pulmonary angiograms at 2 h were performed in 87 patients and then graded in a blinded manner by a panel of six investigators. Of the 42 patients allocated to rt-PA therapy, 79% showed angiographic improvement at 2 h, compared with 67% of the 45 patients randomized to urokinase therapy (95% confidence interval for the difference in these proportions [rt-PA minus urokinase] is -6.6% to 30.4%; p = 0.11). The mean change in perfusion lung scans between baseline and 24 h was similar for both treatments. Three patients (two treated with rt-PA and one with urokinase) had an intracranial hemorrhage, which was fatal in one. The results indicate that a 2-h regimen of rt-PA and a new dosing regimen of urokinase exhibit similar efficacy and safety for treatment of acute pulmonary embolism.