Hemodynamics of the varicocele. Part II. Correlation among the results of renocaval pressure measurements, varicocele scintigraphy and phlebography.

Left renal vein compression occurring mainly with the patient in the upright position, and being less severe or absent in the supine position, was considered to be the main cause of varicoceles. We show that left renal vein compression is, indeed, more severe with the patient in the upright than in the supine position and that it produces a left renocaval pressure gradient that is responsible for the retrograde blood flow in the left testicular vein. This pressure gradient, which was determined in the supine and semierect positions in 34 patients, increased from a mean of 3.8 mm. Hg in the supine position to a mean of 7.8 mm. Hg in the semierect position. On the basis of the assumption that the renocaval pressure gradient measured with the patient in the semierect position determines the presence and velocity of a retrograde flow in the left testicular vein, as shown by the dynamic portion of the varicocele scintigram (see part I), these variables were analyzed and the correlation coefficient proved to be good. Therefore, we conclude that the varicocele occurs when the left testicular vein lacks valves or there is a renogonadal bypass, and the severity of the left renal vein compression in the (semi) upright position determines the velocity of the retrograde flow in the left testicular vein and the size of the varicocele.