Obstruction of the inferior vena cava complicating hemodialysis in polycystic kidney disease.

Two patients with polycystic kidney disease and renal failure developed profound hypotension within 30 minutes after starting hemodialysis. After ruling out all recognized causes of hypotension during early dialysis, we found that their vena cavas were obstructed by compression of the vessels against the spinal column by the greatly enlarged polycystic kidneys. Immediately after bilateral nephrectomy, the patients had dialysis, with removal of large amounts of fluid without causing hypotension. We speculate that compression of the vena cava by massively enlarged polycystic kidneys may significantly contribute to the renal insufficiency by greatly increasing renal venous pressure.