At 7–8 weeks gestation, gonads differentiate into testis in the posterior abdominal cavity. After 8 weeks, through the influence of hormones, the testicles begin their descent into the scrotum. Until 7 months, they remain near the inguinal canal. Before birth or within a few weeks after birth, the testicles complete their descent into the scrotum. As the testicle descends from the abdominal cavity, it brings with it layers of the peritoneum and abdominal wall. Figure 26.2 lists the layers from external to internal order. It is important to note that the external spermatic fascia is derived from external oblique fascia, cremasteric muscle from internal oblique fascia, internal spermatic fascia from transversalis fascia, and tunica vaginalis from peritoneum. If the descent does not occur completely, then patients are labeled as having undescended testicles, which may require medical or surgical intervention.

The testicle is egg shaped with an average length of 5 cm. Testicular function is tightly regulated with signaling from the hypothalamus and anterior pituitary gland. The main function of the testicle is to produce sperm from germ cells and testosterone from Leydig cells . There is another cell type (called Sertoli cells ) that is important for support. Sperm travels through the testicle (lobules, seminiferous tubules, rete testis, epididymis) and vas deferens until it mixes with fluid from the seminal vesicles and prostate to form semen. This combined fluid is eventually expelled into the urethra during ejaculation.

The spermatic cord houses the testicular artery, testicular veins (pampiniform plexus), vas deferens, artery of vas deferens, lymphatic vessels, and nerves. Neural innervation to the testicle is via a complex neural network with significant crossover. Afferent innervation of the scrotum originates via somatic nerves in the genital branch of the genitofemoral nerve, ilioinguinal nerves, and autonomic branches from T10-L1 parasympathetic ganglia [11]. The genitofemoral and ilioinguinal nerves provide anterior scrotal wall and thigh innervation. The posterior scrotal wall is innervated via the perineal branch of the pudendal nerve. There is an alternate autonomic pathway between the pelvic plexus and testis via the vas deferens, which explains the positive response to anesthetic injections to the pelvic ganglia [12]. On average, there are 31 small diameter (less than 1 mm) nerve fibers in the spermatic cord. The three primary sites (trifecta nerve complex) of highest nerve density are (in decreasing order): cremasteric muscle fibers, perivasal tissue and vasal sheath, and posterior peri-arterial/lipomatous tissue [13].

Microsurgical targeted denervation of the spermatic cord (MDSC) is a minimally invasive surgical option for the management of CGSCP after conservative treatments have failed [2, 19]. An animal study to evaluate the effectiveness of the MDSC procedure showed a significant decrease in median number of nerve fibers remaining around the vas deferens after MDSC procedure, compared to sham (MDSC = 3.5 nerves, sham = 15.5 nerves, p = 0.003) [20]. In this procedure (described in detail below), we target tissue in or around the spermatic cord that carries high-density nerve fibers that contribute to chronic pain. Within these nerve fiber s, there are significant anatomic and pathologic differences (Wallerian degeneration) compared to controls (Fig. 26.4) [3, 13]. Targeting these specific areas leads to the preservation of a significant portion of the spermatic cord and potentially fewer complications.

We published our most updated results of the 546 robotic targeted MDSC (RTMDSC) procedures for chronic groin pain [21]. On the last review of our data our total has increased to over 620 patients. Mean preoperative duration of orchialgia in our patients is 2.4 years.The median robotic operative duration was 20 min (range, 10–150 min). Using the externally validated pain assessment tool PIQ-6, we assessed preoperative and postoperative pain. At 6 months there was a 71 % significant reduction in pain and 72 % significant reduction at 1 year. Using the visual analog pain scale, there was an 85 % significant reduction in pain (63 % complete resolution and 22 % greater than 50 %). Complications were limited to one testicular ischemia, two testicular artery injuries (repaired intra-op with no long-term sequelae), one vasal injury (repaired intra-op with no long-term sequelae), 11 hematomas, three seromas, and five wound infections.

There are several advantages to using the robotic platform, which includes improved visualization, decreased tremor, and less dependence on a surgical assistant. Robotic-assisted MDSC seems safe and feasible, and the outcomes appear promising for durable relief.

A 1–2 cm transverse subinguinal incision is made. The incision is carried down until the spermatic cord is reached. The spermatic cord is brought up to the surface. Posterior medial and lateral dissection and cauterization are performed to ligate branches of the ilioinguinal and genitofemoral nerves in this area.

The robot is positioned over the patient. A 0° camera lens is utilized. The right, left, and the fourth robot arms are loaded with Black Diamond microforceps, Maryland bipolar grasper, and monopolar curved scissors, respectively (Fig. 26.5) [3]. If a flexible CO₂ laser fiber is used for dissection, then the fourth arm is replaced with a Black Diamond microforceps to hold the flexguide laser holder (Fig. 26.6) [3].

The anterior cremasteric muscle is divided. The presence of a testicular artery is confirmed with real-time intraoperative micro-Doppler (Vascular Technology Inc, Nashua, NH). The posterior cremasteric fibers and posterior fat component are ablated. The vas is isolated, and generally the artery and vein to the vas are dissected away from the vas. The perivasal tissue is now ablated. Hydrodissection of the perivasal tissue is now performed (Fig. 26.7) [3], using the ERBEJET 2 hydrodissector (ERBE Inc., Atlanta, GA) to ablate residual nerve fibers.