Hydrodissection for improved microsurgical denervation of the spermatic cord: prospective blinded randomized control trial in a rat model.

Microsurgical denervation of the spermatic cord (MDSC) can provide up to an 86% improvement in pain in patients with chronic orchialgia (CO) who have failed conservative management. Failures in MDSC could be due to small diameter nerves (≤1 mm) left behind on the spermatic cord. The objective of this study was to assess if hydrodissection (HD) of the spermatic cord after MDSC could decrease the number of residual nerve fibers without compromising blood flow. Prospective blinded randomized control trial: bilateral MDSC was performed on 22 adult rats (44 cords). HD of the spermatic cord was performed on one side of each rat (side randomized) using the ERBEJET2. The contralateral cord (no HD) was the control for each animal. Blood flow through the vessels was monitored using a micro-Doppler probe. After completion a cross-section of the residual cord was sent to pathology (blinded to technique) to assess for small diameter nerves and signs of damage in vascular integrity. Blood flow had been maintained in the vessels when the ERBEJET2 was set to 6 bar (87 psi). The cord where HD had been performed had a significantly lower total median residual nerve count of 5 (0-10), compared to 8 (2-12) on the non-HD side (p = 0.007). No structural damage was seen in the vessels in the spermatic cord that had undergone HD (gross exam and histology). HD of the spermatic cord significantly decreases residual nerve density without compromising vascular integrity in a rat model.