CHANGES IN VENOUS HEMODYNAMICS AFTER RENAL-TRANSPLANTATION

To explain an occasionally observed transient swelling of the ipsilate ral leg in renal transplant recipients in the absence of deep vein thr ombosis, we took serial measurements of venous outflow resistance and duplex examinations of both legs. Fourteen recipients of a living rela ted donor kidney graft were submitted to strain gauge plethysmography and duplex examination before transplantation and 1 and 6 weeks therea fter. Venous outflow resistance and venous now were measured and the v eins were assessed for thrombosis. Strain gauge plethysmography showed a significant increase in venous outflow resistance in the leg on the side of the renal transplant 1 week after transplantation [0.23 +/- 0 .13 vs 0.40 +/- 0.15 mmHg.s (ml/100 ml)(-1); P < 0.05]. Six weeks late r, the venous outflow resistance had returned to preoperative values [ 0.30 +/- 0.11 mmHg.s (ml/100 ml)(-1); P = NS]. On the contralateral si de, no significant differences were found. Duplex examinations showed no signs of thrombosis. Venous flow measurements in the common femoral vein showed no significant differences. We conclude that the addition al blood supply to the iliac veins results in an increase in venous ou tflow resistance in the ipsilateral leg, which can explain the observe d swelling of this leg and may have implications for the preferred met hod of diagnosis of venous thrombosis after renal transplantation.