Urethral sphincter fatigue after robot-assisted radical prostatectomy: descriptive questionnaire-based study and anatomic basis.
OBJECTIVE
To investigate the hypothesis that preservation of the neurovascular bundle (NVB) contributes to the recovery from sphincter fatigue symptoms after robot-assisted radical prostatectomy (RARP) and to examine the sarcolemmal localization of neuronal nitric oxide synthase (nNOS) and nNOS-positive nerves supplying striated muscles in the pelvic floor.


METHODS
Whether preservation of the NVB influences early continence or sphincter fatigue symptoms was examined in 211 consecutive patients undergoing RARP. Continence and sphincter fatigue symptoms were assessed at 1, 3, and 6 months after surgery. An anatomic study was performed using semiserial sections obtained from 14 male cadavers. The association of continence rate and sphincter fatigue symptoms with preservation of the NVB was assessed by the chi-square test.


RESULTS
There was a significant difference across the bilateral, unilateral, and non-nerve-sparing groups with regard to sphincter fatigue symptoms at 1 month (P=.0004) and 3 months (P=.0326) postoperatively. Sarcolemmal nNOS was detected in the rhabdosphincter (mean, 0.57 per 10 muscle fibers) and levator ani (mean, 1.13 per 10 fibers), with fibers originating from periprostatic nNOS-positive nerves.


CONCLUSIONS
Postoperative sphincter fatigue was reduced by NVB preservation, suggesting that decreased sphincter fatigue may contribute to improvement of continence after RARP. As a background, existence of sarcolemmal nNOS and nNOS-positive nerve terminals arising from the NVB was confirmed in male pelvic floor striated muscles.
Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: hinata@med.kobe-u.ac.jp.
Nobuyuki
N
Hinata
Department of Internal Medicine, Iwamizawa Kojin-kai Hospital, Iwamizawa, Japan.
Gen
G
Murakami
Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan.
Hideaki
H
Miyake
Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan.
Kazushi
K
Tanaka
Department of Anatomy, Tokyo Dental College, Chiba, Japan.
Shin-ichi
S
Abe
Department of Anatomy, Sapporo Medical University School of Medicine, Sappro, Japan.
Mineko
M
Fujimiya
Division of Urology, Department of Surgery, Tottori University Faculty of Medicine, Yonago, Japan.
Atsushi
A
Takenaka
Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan.
Masato
M
Fujisawa
D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D018763:Muscle Fatigue; D052248:Nitric Oxide Synthase Type I / Q000032:analysis; D059351:Organ Sparing Treatments; D011446:Prospective Studies; D011468:Prostatectomy / Q000009:adverse effects* / Q000379:methods*; D012371:Robotics; D011795:Surveys and Questionnaires; D014521:Urethra / Q000201:enzymology / Q000294:innervation* / Q000503:physiopathology*
D052248:Nitric Oxide Synthase Type I