Electrovasogram in Normal and Vasectomized Men and Patients with Obstructive Azoospermia and Absent Vas Deferens

Abstract

The electric activity of the vas deferens (VD) or the electrovasogram (EVG) was recorded in 34 healthy volunteers (mean age 39.3 ± 7.6 [SD] years), 22 patients with obstructive azoospermia (mean age 38.8 ± 9.2 years), 10 after epididymovasostomy performed for obstructive azoospermia (mean age 40.6 ± 4.8 years), 9 with bilaterally absent vasa deferentia (mean age 36.6 ± 7.4 years), 20 after vasectomy (mean age 44.3 ± 7.9 years), and 18 after vasectomy reversal (mean age 58.6 ± 6.8 years). Silver-silver chloride electrodes were applied to the posterior aspect of the upper part of the scrotum and a reference electrode was applied to the lower limb. The intravasal pressure was also measured in 18 subjects during vasectomy reversal operation. Normal EVG manifested as regular slow waves or pacesetter potentials (PPs) which had the same frequency, amplitude, and regular rhythm when the test was repeated in the individual subject. Mean frequency was 6.6 ± 1.5 cycles/min, amplitude was 0.6 ± 0.1 mV, and velocity was 5.6 ± 1.1 cm/s. PPs were followed randomly by action potentials (APs). The EVG in obstructive azoospermia exhibited bradyvasa, i.e., diminished PP frequency, amplitude, and velocity, in 14 patients and a “silent” EVG in 8 patients. Eight of the 10 patients in whom azoospermia persisted after epididymovasostomy had a silent EVG, and the remaining 2 patients whose semen character normalized after the operation revealed normal EVG. A silent EVG was also recorded by the 9 patients with absent vasa deferentia. In vasectomized subjects, PPs from the proximal vasal segment exhibited an irregular rhythm (vasoarrhythmia). During vasectomy reversal, the proximal vasal segment exhibited vasoarrhythmia and high pressure (p<. 05) and the distal segment showed a silent EVG and normal pressure (p.05). EVG performed postvasectomy reversal by 1–6 years showed a normal pattern in 7 subjects who have impregnated their wives and vasoarrhythmic EVG in 11 who could not produce pregnancy. In conclusion, EVG could be characterized for normal and pathologic vasa deferentia. Electrovasography is a simple, noninvasive, and nonradiologic technique that might be used as a diagnostic tool in the investigation of VD disorders and infertility.

Key Words:

• vas deferens
• infertility
• sterility
• azoospermia
• vasectomy
• electrovasogram