Electrovasography in normal and vasectomized men before and after vasectomy reversal

Abstract

The electrical pattern of the vas deferens, or electrovasogram (EVG), was studied in 22 healthy volunteers, 20 vasectomy subjects and 18 individuals after vasectomy reversal. Their mean ages were 38.8 +/- 7.3, 44.3 +/- 7.9 and 58.6 +/- 6.6 years, respectively. Two electrodes were applied to the posterior aspect of the upper part of the scrotum. During the operation of vasectomy reversal, an electrode was applied directly to each of the two vasal segments before and immediately after vasovasostomy. The electrical activity and intravasal pressure were measured. In normal subjects, slow waves or pacesetter potentials (PP) were recorded. They had identical frequency and a regular rhythm from the two electrodes and were consistent in the individual subject on all test days. PP were followed randomly by bursts of action potentials (AP). In vasectomized subjects, PP from the proximal vasal segment exhibited an irregular rhythm (vasoarrhythmia). During operation for vasectomy reversal, the proximal vasal segment recorded vasoarrhythmia whereas the distal segment revealed a silent EVG. Intravasal pressure was normal (p > 0.05) in the distal segment but high (p < 0.05) in the proximal segment. EVG performed 1-6 years after vasectomy reversal showed a normal pattern in four subjects and diminished frequency and amplitude in three. These seven subjects had impregnated their wives and had an obstructive interval of < 3 years. The 11 subjects who did not produce a pregnancy had a vasoarrhythmic EVG and an obstructive interval of > 3 years. In conclusion, an EVG could be identified for normal subjects. Vasectomy resulted in a vasoarrhythmic EVG pattern which proved to be correctable by vasectomy reversal if the obstructive interval was short.

Electrovasogram in patients with obstructive azoospermia and absent vas deferens

“…The current study as well as earlier studies [8,9] have shown that normally the VD, under resting conditions, discharges electric waves in the form of PPs and APs. These waves seem to be responsible for the motile activity of the VD.…”

“…The latter is differentiated as bradyvasa, tachyvasa, or vasarrhythmia. The normal vasal electric rhythm ranges from 4.2 to 8.3 cycles/rain (cpm; mean 6.6 _+ 1.5 cpm) [9]. Bradyvasa is defined as a decrease in PP frequency to less than 2 cpm; tachyvasa, as an increase in the regular frequency to more than 10 cpm; and vasarrhythmia, as an increase in PP frequency with irregular rhythm.…”

“…Respiratory artefacts were excluded by the respiratory transducer attached to the chest wall and cardiac waves, by their characteristic shape. Furthermore, recent studies [8,9] have demonstrated that recordings from the transcutaneous electrode are identical with those from the electrodes directly applied to the VD. These findings prove that the signals recorded transcutaneously are valid and are not artefacts.…”

“…1. EVG of a normal subject, showing pacesetter potentials with regular rhythm and random action potentials (see Shafik [9]) sent for the present study. Their ages ranged from 30 to 46 years (mean 38.8 + 9.2 years).…”

“…1) [8,9]. When the test was repeated, the PPs had a constant frequency, amplitude, and velocity of conduction in the individual dog or human on all test days, whereas the APs occurred randomly, were inconsistent, and were associated with increased intravasal pressure, indicating increased vasal motile activity.…”