Ultrasonic aid in transvenous instrumental dilatation for patients with membranous stenosis of the hepatic portion of the inferior vena cava.

We report two cases of a membranous stenosis of the hepatic portion of the inferior vena cava. Membranotomy was performed with a specially designed instrument similar to a Tubbs' dilator following balloon membranotomy. During the procedures, ultrasonographic observations were made and this technique was confirmed to be effective for proper placing of a balloon and a dilator in the stenotic portion. Follow-up evaluation of the procedures was also feasible with this ultrasonic aid.