Topographical Anatomy of Periprostatic and Capsular Nerves: Quantification and Computerised Planimetry

Bilateral vs unilateral laparoscopic intrafascial nerve-sparing radical prostatectomy: evaluation of surgical and functional outcomes in 457 patients

Study Type - Therapy (case series).

LEVEL OF EVIDENCE

 4. What's known on the subject? and What does the study add? Bilateral nerve-sparing radical prostatectomy still represents an issue for urologists as the indications to perform it depend oft from the personal clinical experience. Moreover, until now data concerning bilateral and unilateral laparoscopic nerve-sparing radical prostatectomy have been limited. This study states that bilateral laparoscopic intrafascial nerve-sparing technique results in superior functional outcomes when compared with unilateral nsLRP and it suggests to prefer a bilateral nerve-sparing technique in younger patients with low-risk, organ-confined prostate cancer.

OBJECTIVE

To evaluate the surgical and functional outcomes in bilateral and unilateral nerve-sparing laparoscopic radical prostatectomy (nsLRP).

PATIENTS AND METHODS

Between January 2005 and May 2009, 457 nsLRP were performed at our clinic. In all, 250 patients underwent a bilateral nsLRP and 207 patients underwent an unilateral nsLRP. One surgeon performed all the operations. All patients presented at biopsy a localized prostate cancer. Demographic data and perioperative and postoperative measurements and outcomes were compared.

RESULTS

The operative times for bilateral nsLRP and unilateral nsLRP were 165 ± 45 min and 130 ± 25 min, respectively. The mean intra-operative blood loss was 450 ± 300 mL and 270 ± 160 mL in the bilateral and unilateral nsLRP groups with a transfusion rate of 3% and 1%, respectively (P = 0.013). Conversion to open surgery was never deemed necessary. Postoperatively, the mean Gleason Score after nsLRP and distribution of tumour stages was similar in the two groups, and the frequency of positive margins in both groups did not present any statistically significant difference. At 12 months, a complete continence was reported in 97% of patients who underwent a bilateral nsLRP and in 88% of patients of the unilateral nsLRP group. At that time, 69% in the bilateral nsLRP and 43% in the unilateral nsLRP groups reported the ability to engage in sexual intercourse.

CONCLUSION

The bilateral laparoscopic intrafascial nerve-sparing technique results in superior functional outcomes with regard to urinary continence and sexual potency, when compared with unilateral nsLRP, reporting similar oncological outcomes.

Intrafascial nerve-sparing radical prostatectomy with a laparoscopic robot-assisted extraperitoneal approach: early oncological and functional results

OBJECTIVE

We investigated whether an intrafascial approach to prostatectomy would provide significantly improved outcomes compared with retropubic and laparoscopic approaches. We performed 50 radical prostatectomies with an intrafascial, nerve-sparing, laparoscopic, robot-assisted extraperitoneal approach.

METHODS

From December 2007 to June 2008, 50 consecutive patients underwent nerve sparing surgery using the intrafascial technique with robotic assistance. All surgeries were performed by the same senior urologist. Patient characteristics and perioperative data were collected prospectively. Oncological outcomes were assessed by pathological examination and postoperative prostate-specific antigen levels. Functional outcomes, including continence, potency, and quality of life, were assessed from patient questionnaires.

RESULTS

The mean operative time was 127 minutes (range: 80-205), the mean hospital stay was 4.2 days (range: 2-9), and the mean catheterization time was 7.8 days (range: 4-11). No perioperative complications occurred. One patient required a transfusion at the postoperative stage. The overall positive surgical margin rate was 12%; adjusted by tumor, nodes, and metastasis stage, it was 9.5% in pT2 and 17% in pT3 disease. At the 1-month follow-up, 66% of the patients were continent (no pad), 12% presented a minimal stress urinary incontinence (1 pad), and 22% required >1 pad(s) per day. Further, 60% of patients exhibited potency (erection sufficient for intercourse: 30% without the use of phosphodiesterase 5 inhibitors, 30% required a phosphodiesterase 5 inhibitor) and the remaining 40% required prostaglandin injections.

CONCLUSIONS

An intrafascial approach with robotic assistance provided satisfactory early functional results with respect to postoperative continence and potency. Long-term oncological results remain to be assessed.

A critical analysis of the current knowledge of surgical anatomy related to optimization of cancer control and preservation of continence and erection in candidates for radical prostatectomy

CONTEXT

Detailed knowledge of the anatomy of the prostate and adjacent tissues is mandatory during radical prostatectomy to ensure reliable oncologic and functional outcomes.

OBJECTIVE

To review critically and to summarize the available literature on surgical anatomy of the prostate and adjacent structures involved in cancer control, erectile function, and urinary continence.

EVIDENCE ACQUISITION

A search of the PubMed database was performed using the keywords radical prostatectomy, anatomy, neurovascular bundle, fascia, pelvis, and sphincter. Relevant articles and textbook chapters were reviewed, analyzed, and summarized.

EVIDENCE SYNTHESIS

Anatomy of the prostate and the adjacent tissues varies substantially. The fascia surrounding the prostate is multilayered, sometimes either fused with the prostate capsule or clearly separated from the capsule as a reflection of interindividual variations. The neurovascular bundle (NVB) is situated between the fascial layers covering the prostate. The NVB is composed of numerous nerve fibers superimposed on a scaffold of veins, arteries, and variable amounts of adipose tissue surrounding almost the entire lateral and posterior surfaces of the prostate. The NVB is also in close, cage-like contact to the seminal vesicles. The external urethral sphincter is a complex structure in close anatomic and functional relationship to the pelvic floor, and its fragile innervation is in close association to the prostate apex. Finally, the shape and size of the prostate can significantly modify the anatomy of the NVB, the urethral sphincter, the dorsal vascular complex, and the pubovesical/puboprostatic ligaments.

CONCLUSIONS

The surgical anatomy of the prostate and adjacent tissues involved in radical prostatectomy is complex. Precise knowledge of all relevant anatomic structures facilitates surgical orientation and dissection during radical prostatectomy and ideally translates into both superior rates of cancer control and improved functional outcomes postoperatively.

Anatomical description of the periprostatic nerves in the male rhesus monkey (Macaca mulatta)

OBJECTIVES

Recent publications have revealed a variable course of the periprostatic nerves in humans. It is unclear to what extent nerves outside the dorsolateral region of the prostate are involved in the physiology of erectile function. As functional studies in humans are limited by ethical aspects investigations in animal models could provide further insight. The intention of this study was to give a detailed description of the topographical anatomy of autonomic nerves along the seminal vesicles and the prostate in male rhesus monkeys (Macaca mulatta) to investigate its suitability as an animal model for future physiological studies.

METHODS

Wholemount serial sections of pelvic organ blocks of ten male rhesus monkeys were investigated. Autonomic nerves were stained with an antibody against S100.

RESULTS

Autonomic nerves were dispersed along the dorsolateral to the ventrolateral aspect of the capsule of the prostate within a layer of connective tissue. There was no accumulation of vessels and nerves in the dorsolateral position of the prostate. The prostate is located dorsally to the urethra and does not encircle it. No adjacent nerves were found in the cranial two-thirds of the seminal vesicles.

CONCLUSIONS

The male rhesus monkey is limited suitable as an animal model for studies on the periprostatic nerves provided the following differences to humans are considered: the special topography of the prostate, the nerve course along the seminal vesicles and the missing nerve accumulation dorsolaterally to the prostate.

Neuroanatomy of the male pelvis in respect to radical prostatectomy including three-dimensional visualization

The neuroanatomical structures of the radical prostatectomy (RP) are extensively discussed for their existence, localization and function. Especially structures, e.g. the so-called neurovascular bundle (NVB) that are points of debate in numerous anatomical studies. We review the literature and present our observations in cadaveric specimens, to reconstruct neuroanatomical structures in three dimensions (3D) with the use of appropriate computer applications and produce images of operative fields. We used an internet PubMed survey (http://www.ncbi.nlm.nih.gov) to review recent publications and included back copies of historical neuroanatomical studies from our own library. Our own experimental cadaveric (specimens preserved in Thiel's solution) studies of the autonomic nerve supply of the lower urinary tract were also reviewed. Visualization of the pelvic anatomy and neuroanatomy was done using computer-based software packages. No unified terminology for the structures of the NVBs can be presented to date. The innervation of the smooth muscular structures of the urethra and the complex morphology of urethral sphincter remain unclear. Our cadaveric studies showed that nerves are located on the lateral aspect of the prostate in addition to the NVBs described at the dorsolateral side of the prostate. The neuroanatomical investigations of the male pelvis and visualization of the structures in 3D enable the presentation of operative sites as seen intraoperatively. Moreover, dynamic depiction of the pelvic floor is also possible.