Anatomy and Physiology of the Epididymis
The epididymis is a long, tightly coiled single tubule located on the posterolateral aspect of the testis. The epididymis has a rich blood supply from both testicular and deferential vessels. Because of extensive collaterals, either the deferential or testicular arterial branches to the epididymis can be ligated without affecting epididymal function. However, inadvertent damage to the testicular artery during epididymectomy may compromise testicular viability and function.
Indication for Epididymectomy
Although some are controversial, the indications for epididymectomy are chronic infections unresponsive to antibiotics, abscess formation with or without draining fistulas, tumors, chronic pain, trauma, and postvasectomy syndrome (epididymitis or vasitis nodosa). When inflammatory cases progress and do not respond to medical therapy, then surgical intervention may be indicated.
Of note, pain may not be completely relieved by surgery in patients with chronic pain syndrome. Some surgeons may perform cord denervation as part of the epididymectomy for postvasectomy syndrome.
Although the surgical approach for epididymectomy is relatively straightforward, the presence of significant inflammation, fibrosis, or anatomic distortion may make this procedure difficult.
After the testis is delivered through an anterior scrotal incision, the tunica vaginalis is opened to provide access to the epididymis and vas deferens. The surgeon can approach epididymectomy from above or below.
From above, the straight portion of the vas deferens is ligated and the proximal vasal lumen fulgurated or ligated. The convoluted vas is then carefully dissected from the spermatic cord. The surgeons’ thumb and forefinger carefully pinches the spermatic cord, keeping the epididymis anterior during dissection ( Fig. 113.1 ). Lightly incising the adventitial junction between the epididymis and testis allows careful blunt and sharp dissection and lifting of the tail region. At the junction of the middle and upper third of the epididymis, the common origin of the testicular and epididymal arteries are encountered (see inset, Fig. 113.1 ). Taking care to preserve the blood supply to the testis, only the epididymal artery is ligated.