Acute effect of electrical stimulation of the dorsal genital nerve on rectal capacity in patients with spinal cord injury.
BACKGROUND
Constipation and fecal incontinence are considerable problems for most individuals with spinal cord injury (SCI). Neurogenic bowel symptoms are caused by several factors including abnormal rectal wall properties. Stimulation of the dorsal genital nerve (DGN) can inhibit bladder contractions and because of common innervation inhibitory effects are anticipated in the rectum too. Therefore, DNG could have a future role in the treatment of neurogenic fecal incontinence.


OBJECTIVE
To study the effect of acute DGN stimulation on the rectal cross sectional area (CSA) in SCI patients.


METHODS
Seven patients with complete supraconal SCI (median age 50 years) were included. Stimulation was applied via plaster-electrodes using an amplitude of twice the genito-anal reflex threshold (pulse width: 200 μs; pulse rate: 20 Hz). A pressure controlled phasic (10, 20 and 30 cmH(2)O) rectal distension protocol was repeated four times with subjects randomized to stimulation during 1st and 3rd distension series or 2nd and 4th distension series. The rectal CSA and pressure were measured using impedance planimetry and manometry.


RESULTS
All patients completed the investigation. Median stimulation amplitude was 51 mA (range 30-64). CSA was smaller during stimulation and differences reached statistical significance at distension pressures of 20 cmH(2)O (average decrease 9%; P = 0.02) and 30 cmH(2)O (average decrease 4%; P = 0.03) above resting rectal pressure. Accordingly, rectal pressure-CSA relation was significantly reduced during stimulation at 20 (P=0.03) and 30 cmH(2)O distension (P=0.02).


CONCLUSIONS
DGN Stimulation in patients with supraconal SCI results in an acute decrease of rectal CSA and the rectal pressure-CSA relation.
Department of Surgery P, Aarhus University Hospital, Aarhus, Denmark.
J
J
Worsøe
L
L
Fynne
S
S
Laurberg
K
K
Krogh
N J M
NJ
Rijkhoff
D000328:Adult; D000368:Aged; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D005835:Genitalia / Q000294:innervation; D006801:Humans; D008297:Male; D008875:Middle Aged; D055496:Neurogenic Bowel / Q000209:etiology / Q000628:therapy*; D012007:Rectum / Q000294:innervation; D013119:Spinal Cord Injuries / Q000150:complications / Q000628:therapy*