Electromyographic and manometric anorectal evaluation in children affected by neuropathic bladder secondary to myelomeningocele.

BACKGROUND: Fecal incontinence, with or without persistent constipation is often underestimated in children affected by spina bifida. Medullar lesions to the L-S metameres result in a slowing of rectal and/or rectal-sigmoid motility, loss of anal or rectal sensation, deranged external anal sphincter function, altered motility of the anal levator muscles, and loss of motor coordination of the internal sphincter. We conducted an electromyographic and electromanometric evaluation of the anorectal tract in a group of children affected by myelomeningocele (MMC) in an attempt to evaluate the degree of functional damage and to provide appropriate treatment. METHODS: Anorectal manometry was conducted in 83 children affected by MMC (2-16 yrs, mean age: 8.4 yrs); surface electromyography was also performed in 37 of these children. We thus evaluated overall sphincter pressure, the inhibitory anal reflex, the rectal sphincteric reflex and rectal motility during stimulation and at rest. Recording perfusion catheters (0.1 ml/sec) were placed at rectal and anal level; rectal stimulation was conducted with an endorectal balloon. RESULTS: In all patients there was a reduction in overall sphincter pressure (15-25 mmHg; n.v. 45+/-25 mmHg) and the functional length of the anal canal (1-1.8 cm) compared with age matched controls. The inhibitory anal reflex was normal in all patients, although its amplitude, duration and sensitivity were not constant. Similar findings were obtained for the rectal-sphincteric reflex. The rectal sigmoid motility results were difficult to interpret: sudden, fast and high pressure waves of peristaltic progression were followed by prolonged pauses. No correlation was found between urodynamic and anorectal manometric data. Treatment consisted in daily emptying of the rectum so as to avoid fecal retention. Fifteen patients, who presented prolapse and sphincteric hypotonia ( </=10 mmHg), underwent cerclage by 2/0 prolene, with sustained good RESULTS. CONCLUSIONS: While evaluation parameters of the neuropathic bladder are well standardised, data on the neuropathic rectum are contradictory. Moreover, the results of functional examination are not always an aid to treatment strategy. Therefore, further studies are required to establish an appropriate diagnostic-therapeutic protocol.