The frequency and efficacy of differential sacral roots innervation to bladder detrusor in Asian people

Staggered rhizotomy of anterior and posterior sacral roots for bladder reservoir function in spinal cord injury: a canine experimental study and preliminary clinical report

OBJECTIVE

To report an experimental study and preliminary clinical results of staggered anterior and posterior sacral rhizotomy for restoring function of the bladder and preventing reflex incontinence in supra-conal spinal cord injury (SCI).

METHODS

Ten T10 spinal cord transected mongrel dogs were divided into three groups. In group 1 (n= 2), laminectomy only was performed (control). In group 2 (n= 4), all L7-S3 posterior roots were microsurgically cut (complete deafferentation). And in group 3 (n= 4), the L7, S1, S3 posterior roots and S2 anterior root were cut (staggered deafferentation and deefferentation). Intraoperative electrical stimulation and postoperative cystometrography (CMG) were carried out. In the clinic, three patients with spastic bladder caused by a supra conal complete SCI underwent staggered rhizotomy and were followed up for 6 years.

RESULTS

In the canine experimental study, resection of the S2 anterior root combined with L7, S1 and S3 posterior rhizotomy, stimulating the S2 posterior root (four dogs) resulted in a minimal rise in pressure in the bladder and urethra, which was only about 10% of that obtained by stimulating the S2 proximal posterior root while its anterior counterpart was intact (eight dogs, Student's t-test, P < 0.01). The CMG study showed that groups 2 and 3 had similar volume/pressure curves; in both groups the tendency was to develop flaccid bladders. In the clinic, three cases underwent staggered rhizotomy of the anterior and posterior roots in S3 and S4. Good bladder reservoir and compliance was achieved over six years of follow-up.

CONCLUSION

Staggered rhizotomy of the anterior and posterior sacral roots at different spinal cord levels has the same denervation effect as a complete posterior rhizotomy, and good bladder reservoir function can be achieved by this procedure.

Reconstructed bladder innervation above the level of spinal cord injury to produce urination by abdomen-to-bladder reflex contractions

Neurogenic bladder dysfunction following spinal cord injury is a major medical and social problem for which there is no ideal treatment strategy. This paper describes the authors' attempts to establish bladder reinnervation, by establishing an abdomen-to-bladder reflex pathway, in a patient with an injury to the conus medullaris.

Sacral anterior root stimulated defecation in spinal cord injuries: An experimental study in canine model

AIM: To investigate whether there was a dominant sacral root for the motive function of rectum and anal sphincter, and to provide an experimental basis for sacral root electrically stimulated defecation in spinal cord injuries.

METHODS: Eleven spinal cord injured mongrel dogs were included in the study. After L4-L7 laminectomy, the bilateral L7-S3 roots were electrostimulated separately and rectal and sphincter pressure were recorded synchronously. Four animals were implanted electrodes on bilateral S2 roots.

RESULTS: For rectal motorial innervation, S2 was the most dominant (mean 15.2 kPa, 37.7% of total pressure), S1 (11.3 kPa, 27.6%) and S3 (10.9 kPa, 26.7%) contributed to a smaller part. For external anal sphincter, S3 (mean 17.2 kPa, 33.7%) was the most dominant, S2 (16.2 kPa, 31.6%) and S1 (14.3 kPa, 27.9%) contributed to a lesser but still a significant part. Above 85% L7 roots provided some functional contribution to rectum and anal sphincter. For both rectum and sphincter, the right sacral roots provided more contribution than the left roots. Postoperatively, the 4 dogs had electrically stimulated defecation and micturition under the control of the neuroprosthetic device.

CONCLUSION: S2 root is the most dominant contributor to rectal pressure in dogs. Stimulation of bilateral S2 with implanted electrodes contributes to good micturition and defecation in dogs.