Treatment of severe intermittent claudication by controlled defibrination.

Fifteen patients with severe intermittent claudication were treated by therapeutic defibrination with subcutaneous injections of ancrod for 5 weeks. Mean plasma-fibrinogen was maintained below 50% of the initial value throughout the treatment period. This reduction in plasma-fibrinogen was accompanied by a parallel fall in whole-blood viscosity and a pronounced clinical improvement. Objective measurements showed maximum benefit on the 21st day of treatment, when the mean resting ankle/arm pressure index had increased by 37%, the post-exercise pressure index had increased by 50%, and the time taken for the pressure index to return to a resting value after a constant exercise had decreased by 33%. (The claudication-count had increased by 59%).