AB010. The clinical application of relevant local prostate anatomy in laparoscopic radical prostatectomy

Background: In order to improve the curative effect of laparoscopic radical prostatectomy (LRP), to further improve the postoperative urinary continence and other indicators, the relevant anatomy in LRP was conducted. Based on the anatomical results, several processes of the relevant steps were improved accordingly.

Methods: Eleven cadavers were used and puboprostatic ligaments, dorsal vascular complex, detrusor apron, denonvilliers fascia, membranous urethra and surrounding structures were observed and measured. Then, the apex of prostate and membranous urethra were observed in tissue section. MDR and the structures of nerve and vascular on both sides of the urethra were observed. According to the anatomical results, key steps of LRP were improved. The early postoperative urinary continence was also recorded.

Results: Anatomical results: (I) the general anatomical results showed that the PPL was located in front of the prostate, and the left and right sides were located at 10–11 o’clock and 1–2 o’clock. PPL was hourglass-shaped. The pubis end was measured 7.5 mm. The middle width was 6 mm and prostate width was 12 mm. From the pubic bone to the prostate end was about 9 mm. PPL is not a single ligament. From the pubic bone to the prostate and membranous urethra was a number of ligaments issued; (II) detrusor apron is located in front of the prostate, covering almost full length of the prostate. Detrusor apron was triangle distribution in the prostate. In the bottom of the prostate detrusor apron was distributed from 10–2 o’clock, while in the apex detrusor apron was distributed from 11–1 o’clock. The middle is thickest, and at the both ends, it migrated gradually thinning and even disappeared; (III) in general anatomy and tissue sections, MDR structure was found and it is the extending of rectum inherent fascia and denonvilliers fascia. It is inferred that MDR possessed the role of strengthening the urethral sphincter and rectal urethral muscle stability. At the same time, vascular structure was observed behind the MDR, which may be related to the urethral sphincter and rectal urethral muscle blood supply. Striated urethral sphincter was missing behind the membranous urethra and the missing part was filled with MDR. The width and thickness of missing part was different. The improved points in LRP: (I) the posterior urethral tissue of the membranous part should be preserve. Excessive separation should be avoided, which could reduce bleeding and effectively prevent urethral retraction; (II) the MDR tissue and the fascia of the posterior urethra were sutured to ensure the integrity of the posterior fascia; (III) preserve the PPL as much as possible. If PPL is cut off, the urethra of the membranous urethra should be suspended after the anastomosis. Early postoperative continence rate: we retrospectively analyzed the early postoperative urinary continence in 98 patients with LRP. Fifty-six of them underwent modified LRP and 42 with conventional LRP. The results showed that the 1-month urinary continence rate was 57% in the traditional LRP group and 85% in the modified LRP group.

Conclusions: The fine anatomy of LRP related structures is the theoretical basis for the improvement of LRP surgery. After conducting the modified LRP surgery based on anatomy, the early urinary continence rate in our center was obviously improved.

Keywords: Local prostate anatomy; radical prostatectomy