Walsh described three layers covering the anterolateral surface of the prostate [22]: the prostatic fascia overlaying the prostatic capsule and levator fascia (fascia diaphragmatica pelvis superior). Both fascias fuse laterally to form the lateral pelvic fascia covered by the endopelvic fascia (fascia pelvis parietalis) reflecting off the transversalis fascia. This area also is described as tendinous arch of the pelvis. Posteriorly, there are two layers [23]: Denonvilliers’ fascia (Prostato-seminal-vesicular fascia; septum retrovesicale) and the prostatic capsule (Fig. 53.4). The neurovascular bundles (NVB) run along the posterolateral part of the prostate between levator and prostatic fascia and contain branches from the inferior vesical arteries running medial to cavernosal nerve branches originating from the pelvic plexus. These vessels enter the capsule through the prostatic fascia [38]. Some authors describe the levator fascia also as periprostatic or parapelvic fascia [24, 25].

For preservation of continence, the course of intra-pelvic branches of the pudendal nerve is more relevant than the course of neurovascular bundles [5, 34]. The N. pudendus has three branches, (i) nervi rectales inferiors, (ii) nervi perinealis and (iii) nervus dorsalis penis. The perineal rami support the penile muscles (m. bulbospongiosus, m. ischiorectalis, m ischiocavernosus) and the striated urethral sphincter. Lesions of the perineal branches lead to incontinence. Thus, the anatomical course of pudendal vessels and nerve is important regarding postoperative continence after radical prostatectomy. A., V. and N. pudendus enter the small pelvis through the Foramen ischiadicus minus then following the canalis pudendalis (Alcock’s canal). Thereafter the nerve divides medially into its three branches. The perineal rami supporting the striated urethral sphincter run underneath the levator fascia (fascia diaphragmatica pelvis superior) as demonstrated by Hollabaugh et al. [34].

The urethral sphincter apparatus consists of the horse-shoe-shaped rhabdosphincter and the smooth-muscle longitudinal and circumferential lissosphincters [29]. Additionally, the prostate is connected laterally to the urethra by thickened fascial band components (Walsh’s pillars, Müller’s ischioprostatic ligaments). Anteriorly, puboprostatic (pubo-vesical) ligaments suspend the urethra. For preservation of the puboprostatic collar it is important to keep this part completely intact (Fig. 53.5). Posteriorly, the sphincter apparatus is supported by the median fibrous raphe respectively rectourethralis muscle [22, 23, 31]. Additionally, the striated sphincter is flanked by thickened anteriomedial edges of the anterior levator ani muscle (i.e. urogenital hiatus) forming an incomplete sling behind the urethra. On contraction they forcefully propel the prostate and prostatourethral junction upward and forward enabling quick stop of urination [23, 33, 34]. This movement is countered by the horse-shoe shaped striated sphincter contracting downwards and backwards.

The precise anatomy of the bladder neck and its effect on continence has proven difficult to clarify [16–18, 23]. In the transverse plane, the bladder neck (BN) is composed of two different muscles, the ventrolateral and dorsal longitudinal muscles, which are positioned in an oblique direction. When the BN is examined in a truly transverse direction, there is a distinct circular muscle called the musculus sphincter vesicae [23] possibly representing the rationale for bladder neck preservation.

Both, the somatic pudendal nerve and the autonomic branches of the pelvic plexus are involved in urinary continence mechanism. Somatic motor innervation passes from the anterior horn of S2-4 segments and travels to the external sphincter via an intra- and an extrapelvic branch of the pudendal nerve. Additional intrapelvic extrapudendal nerve fibres from S2-3 pass lateral to the pelvic plexus and then continue along the dorsolateral surface of the rectum until they disappear into the levator ani muscle and terminate in the urethral sphincter [34]. In addition to the efferent autonomic and somatic nerve fibres innervating the sphincteric musculature, intrapelvic afferents from the membranous urethra contribute to urinary continence. Intact afferents leads to a conscious sensation of urine entering the membranous urethra inducing either a spinal reflex or voluntary contraction of the rhabdosphincter. These afferent fibres run in branches of the pelvic plexus and the intrapelvic branch of the pudendal nerve.

Prior to final positioning we place a balloon-catheter in the rectum and block it with 30 cc of air. After division of the DVC, the balloon is blocked with 50–60 cc (Fig. 53.6). This facilitates apical dissection by demonstrating the rectal fascia propria [23, 24] and is useful during identification of the apex of the prostate and the neurovascular bundle. Additionally, the risk of rectal injury can be minimized.

The preservation of levator fascia requires a high medial incision of the endopelvic fascia just below the insertion of the puboprostatic ligaments. Subsequently the cleavage plane between the prostatic and levator fascia is developed bluntly using a right angle dissector (Video, Fig. 53.3d). Alternatively, this plane can be reached by careful incision of the endopelvic fascia lateral to the base of the prostate. During RALP, the same can be effectively carried out using the Metzenbaum scissors to bluntly sweep away the levator fascia. Thus, the perineal rami of the pudendal nerve running to the striated urethral sphincter remain untouched covered by levator fascia.

For preservation of puboprostatic collar DVC is sutured over the mid-part of the prostate. During division of DVC we place a 120° endodissector at prostato-vesical junction (Fig. 53.5) to provide counter-traction. The plane between DVC and anterior surface of prostate (McNeal’s anterior fibromuscular stroma; [27]) is dissected by cold scissors (Fig. 53.7a). In case of RALP, we use monopolar scissors for this step. This results in rotation of prostate towards the surgeon to reach urethra and the anterior striated sphincteric complex (Fig. 53.7b), thus straightening the prostato-urethral angulation varying from 35 to 90° [23, 27].