Muscular urinary sphincter: electrically stimulated myoplasty for functional sphincter reconstruction.
OBJECTIVE
To reconstruct an electrically stimulated muscular urinary sphincter (MUS) using a tailored gracilis muscle free flap with intact nerve.


METHODS
Unilateral surgically tailored gracilis muscle free flaps were transferred into the pelvis in eight dogs, leaving the obturator nerve intact. The muscle's pedicle vessels were anastomosed to the inferior epigastric artery and vein in the pelvis and the muscle was wrapped around the bladder neck. Electrodes were inserted into the MUS and connected to a programmable pulse generator. After 8 weeks of training the MUS, the pulse generator was programmed to be "on" for 4 hours and "off' for 15 minutes in a continuous cycle. Urodynamic studies were performed periodically, and at the end of the experiment the MUS and proximal urethra were harvested for histology. Three control dogs had sham operations.


RESULTS
All MUS's functioned well following the procedure. Histology of the MUS/urethra complex showed no evidence of stricture. Except for one dog, all urethras were easily catheterized.


CONCLUSIONS
This electrically stimulated innervated free-flap MUS technique effectively increases bladder outlet resistance without producing urethral obstruction.
Department of Surgery, School of Medicine, University of Louisville, Kentucky, USA.
M M
MM
Palacio
V C
VC
Van Aalst
G A
GA
Perez Abadia
R W
RW
Stremel
P M
PM
Werker
X
X
Ren
G D
GD
Petty
S J
SJ
Heilman
J G
JG
Van Savage
A
A
Garcia Fernandez
M
M
Kon
G R
GR
Tobin
J H
JH
Barker
D000818:Animals; D004285:Dogs; D004558:Electric Stimulation; D005260:Female; D018482:Muscle, Skeletal / Q000294:innervation / Q000637:transplantation*; D013524:Surgical Flaps; D014521:Urethra; D014549:Urinary Incontinence / Q000601:surgery*; D013520:Urologic Surgical Procedures / Q000379:methods