A total of 24 patients with renal cell carcinoma involving the inferior vena cava underwent thoracoabdominal radical nephrectomy with removal of tumor thrombus by an open or closed technique. The tumor extended in the inferior vena cava to the level of the renal or lower hepatic veins in 18 patients and it reached the level of the diaphragm or right atrium in 6. Of the 24 patients 3 with preoperative findings minimally suggestive of disseminated disease were shown later to have metastases in the questionable areas, 3 with disease at the level of the diaphragm had incomplete resections, 4 had metastases to regional lymph nodes and 1 had questionable preoperative findings and lymph node metastases. Only 13 of the 24 patients (54 per cent) did not have either disseminated or residual tumor postoperatively. The mean survival duration of this subgroup (20 months) was comparable to that of the group as a whole (21 months). However, 4 patients from this subgroup are free of disease, with a mean followup of 30 months. There was 1 postoperative death. Morbidity, including renal failure, intraoperative hypotension and sepsis, was common. The results in this series suggest that the prognosis for patients with renal cell carcinoma and inferior vena cava involvement is guarded.

Abstract. A radioimmunoassay for arginine vasopressin has been developed that is sensitive to the hormone at 1 pg/ml. When plasma was filtered on G-25 Sephadex, immunoreactivity was detected in three regions. Endogenous arginine vasopressin was the third and smallest of the peaks and was recovered just after the salt. By combining gel filtration with immunoassay, we have made precise measurements of arginine vasopressin in a few milliliters of plasma.Introduction. Arginine vasopressin (AVP), a nonapeptide of the posterior pituitary gland, is the major hormonal regulator of water conservation in man and most other mammals. Many details of vasopressin physiology have been obscure because simple precise methods for measuring the hormone concentration in plasma have not been available.We have developed a radioimmunoassay that is sensitive to the hormone at 1 pg/ml and in which AVP reacts much more strongly than lysine vasopressin or