Phlebographic classification of anatomic variants in the right internal spermatic vein confluence

Male varicocele is a clinical dysfunction caused by a pathological venous reflux. Knowledge of anatomic variants of the internal spermatic vein confluence is fundamental for the technical success of percutaneous treatment. While numerous studies have analysed the phlebographic anatomy of the left internal spermatic vein, no exhaustive description exists for the right internal spermatic vein.

From a retrospective review of 3229 patients treated percutaneously between 1988 and 2003, we extrapolated the phlebographic images of patients with incontinence of the right internal spermatic vein only. Mean patient age was 24.6 (range 14-46) years. Indication for treatment was presence of pain in the right inguinal region and absence of a history of trauma and/or seminal-fluid alterations. Phlebography had been performed with transbrachial access using a tilt table and a multipurpose angiographic catheter. Contrast medium was injected into both the inferior vena cava and the renal vein. Selective catheterisation of the internal spermatic vein was then performed to assess the radiological characteristics of the vessels prior to sclerosis.

There were 93 cases of incontinence of the right internal spermatic vein only (2.8%). In the first group of patients (seven cases, 7.5%), the right internal spermatic vein drained exclusively into the renal vein; the injection of contrast medium during a Valsalva manoeuvre allowed visualisation of the vein almost as far as the iliac level. In most cases, the vein appeared uniformly dilatated and without valvular systems along its course. In the second group (21 cases, 22.5%), the vein drained into both the renal vein and the inferior vena cava, with one branch showing functional predominance over the other: selective catheterisation was easier to perform on the first branch. Selective catheterisation confirmed dilatation of the vein as well as the absence of valvular systems. In most patients, (65 cases, 69.8%), the internal spermatic vein drained into the inferior vena cava; the confluence was double in five patients and single in 60 patients. Visualisation of incontinence was limited to the initial 5-10 cm of the vein in 13 cases; however, vein dilatation and absence of valvular systems were confirmed beyond the semicontinent valve.

Interventional treatment is one of the therapeutic options for male varicocele, but the method is limited by the presence of anatomic variants or aberrant supplying vessels, which make catheterisation and sclerosis of the internal spermatic vein difficult if not impossible. Interventional radiologists must have a thorough knowledge of anatomic variants of the right internal spermatic vein to be able to perform the procedure within a reasonable amount of time and reduce radiation exposure.