The value of scrotal thermography as compared with selective retrograde venography of the internal spermatic vein for the diagnosis of "subclinical" varicocele.

The accuracy of scrotal thermography as a diagnostic method to confirm or detect spermatic venous reflux in patients with palpable and subclinical varicocele, respectively, was evaluated. In all, 118 scrotal thermograms were performed in 110 patients, and the results were compared with the findings by selective retrograde venography of the internal spermatic vein whenever required. Normal thermograms were recorded in 23 oligospermic men without varicocele. Of 39 patients with palpable varicocele, 37 had abnormal thermograms; normal recordings occurred in 2 patients with associated unilateral testicular atrophy. Among 36 men suspected of having subclinical varicocele, 19 had abnormal thermograms and 16 presented reflux on the venogram. Venography was performed in 5 of the remaining 17 men with normal thermograms; only 1 had reflux. Screening for varicocele by means of scrotal thermography thus revealed reflux in 16 of 36 patients with unexplained infertility. Postoperative thermograms were disturbed in 6 of 20 cases, 5 of which presented reflux. Only 1 of 14 postoperative patients with normal thermograms underwent venography, and no reflux was demonstrable. Both the difference in temperature between the affected and contralateral hemiscrotum and the area of hyperthermia were significantly greater in patients with grades II and III varicocele, compared with those with subclinical and grade I varicocele. It is concluded that scrotal thermography is a valuable screening method for the detection of spermatic venous reflux. The technique allows selection of patients to be subjected to retrograde venography.