Factors Producing Spurious Obstruction of the Inferior Vena Cava in Infants and Children With Abdominal Tumors

Abstract

Inferior vena cavography has been suggested for initial roentgenographic evaluation of abdominal masses in infants and children (2, 3, 6, 7). The procedure has been proposed as a means of determining both malignancy and operability (2). The two common tumors encountered, Wilms's tumor and neuroblastoma, are readily diagnosed in the majority of patients by ordinary intravenous urography. We wish to report serious problems, seemingly inherent in the interpretation of inferior vena cavograms, that critically limit their usefulness. There is a high incidence of faint to nonvisualization of the inferior vena cava accompanied by massive shunting through pelvic veins to the rich retroperitoneal ascending lumbar collateral channels leading to the azygos system. These pathways were repeatedly seen in patients in whom the inferior vena cava was either normal at operation or merely displaced and partially compressed. The factors producing such spurious caval obstruction include a large mass adjacent to the inferior vena cava, the lesser effects of crying and straining (Valsalva maneuver), and the supine versus prone positions. Technic of Inferior Vena Cavography To be practical, the technic of inferior vena cavography must be applicable to the small infant with a mass who is referred for urography. Cavography will yield the pyelogram but must be accomplished through a leg vein puncture. The femoral vein is avoided in the Babies Hospital, New York, for fear of both possible hip joint infection and arterial spasm with gangrene. The catheter technic is not accomplished in such small patients with enough facility to make it practical. After preliminary frontal and lateral abdominal films have been examined for osseous metastases (which would largely exclude Wilms's tumor) and for calcifications (which usually mean neuroblastoma), a saphenous vein is used as the site of injection. Dependent on the age of the patient, scalp vein needles ranging from No. 19 to as small as No. 21 or No. 23 can be used. Tourniquets are of value (3) when employed on the opposite leg, to decrease dilution of the bolus. On the side of injection they force the contrast medium into deep veins and, when released from this side, allow it to travel as a bolus to the abdomen. Their major disadvantages are the resultant crying, straining, and struggling which increase the shunting to retroperitoneal collateral channels (1). The first study, made with the baby supine, consists of rapid injection of 2.5 cc/kg of 50 per cent sodium diatrizoate (or 60 per cent meglumine iothalamate), with a cross-table lateral film of the abdomen taken as the last cubic centimeter or so is injected. One to two minutes later, a second injection, equal in amount, is made for the supine anteroposterior projection. The patient has not been moved for these exposures, which can be followed by routine five-minute supine and ten-minute prone abdominal films.