Iatrogenic renal artery thrombosis

Renal calculi were removed from 2 women--in 1 case by renal bisection and in the other by nephrolithotomy. In each case a small bulldog clamp was applied to the renal artery for less than 30 minutes. Both patients suffered renal artery thrombosis necessitating nephrectomy. When the histories of these patients were reviewed the common factor found was oral contraceptives, suggesting that oral contraceptives may predispose to renal artery thrombosis.