Experimental Study Of Bladder Nerve Change After Spinal Cord Injury In Rat

Bladder dysfunction after spinal cord injury is a social and medical problem whichhas not been well solved, it often cause severe urinary retention, urinary tract infection andeven renal failure, it is the main cause of death for patients with paraplegia. The idealtreatment of bladder dysfunction after spinal cord injury is rehabilitation of automaticfunctional voiding by restoring central nerve control. In recent years, many scholars havecarried out the studies of reconstruction of bladder innervation after spinal cord injury, theresults are encouraging.The present operation of Bladder nerve reconstruction surgery after spinal cord injuryis usually performed by anastomosing the proximal nerve roots which dominate the bodyand the distal nerve roots which dominate the urinary bladder. Until the proximal nerveregenerate into the distal nerve, innerve the bladder to form bladder reinnervation. If thenerve roots which dominate bladder degenerate after spinal cord injury, it is bound to affectthe anastomosis nerve ingrowth effect, thus affect the bladder nerve reconstruction result.Therefore, we study the spinal nerve roots to know which roots dominate urinary bladderin rat, and study the pathological changes of spinal nerve roots which dominate bladderafter spinal cord injury in rat.To neurogenic bladder patient after spinal cord injury, suprapubic cystostomy iscommonly used in clinical treatment in order to achieve long-term drainage of urine andprotect the kidneys. Current clinical suprapubic catheter require a long-term urine drainagebag which seriously affecting the patient’s daily life, especially for the patient withoutdysfunction of the limbs. Therefore, we design a new suprapubic catheter without urinedrainage bag, in order to remove the trouble of carrying urine drainage bag and facilitatethe patient’s daily life.Part oneExperime ntal study on innervation of bladder by lumbosacral ventral roots in ratObjective To observe the different bladder function dominant role of lumbosacralventral roots in the rat, and the gender difference of the different bladder function dominaterole of lumbosacral ventral roots.Methods10male SD rats and10female SD rats were included in the study. The right spinal ventral roots of L4~S4were electrical stimulated separately and intravesicalpressure,vesical plexus action potential, vesical smooth muscle complex action potentialwere recorded through the biological signal processing system of SMUP-PC type.Results The L4、L5、S4spinal ventral root was not involved in bladder innervation,the L6~S3spinal ventral roots were involved in bladder innervation in rat. The S2spinalventral roots were the most dominant nerve. The lumbosacral ventral roots have the similareffect on bladder innervation between male and female rats.Conclusion The lumbosacral ventral roots have the different effect on bladderinnervation, and there is no gender difference. Part twoExperime ntal study of bladder nerve change after spinal cord injury in ra tObjective To study the pathological change of spinal nerve roots which dominatebladder after spinal cord transection and cone damage in rat.Methods36female SD rats were randomly divided into three groups, group A(control group,n=12), no special treatment; group B (spinal cord transection group,n=12),the spina cord was completely transected at T9to T11vertebral level; group C (cone injurygroup,n=12), the spinal cord cone was damaged by weight-dropping technique between theT12to L6vertebral level. The S1, S2nerve roots were removed at the site just distal to thenerve ganglion on6weeks,12weeks after operation respectively. Hematoxylin-eonsinstaining and toluidine blue staining were used to observe pathological change of the nervefibers, the density of myelinated nerve fibers was calculated by computer..Results The nerve fibers in spinal cord transection group were more looselyarranged than that in control group. The density of myelinated fibers in spinal cordtransection group was lower than that in control group, but the difference was notstatistically significance. In cone injury group, the nerve fibers significantly reduced, a lotof connective tissue and Schwann cells were seen between nerve fibers. The density ofmyelinated fibers in cone injury group was lower than that in spinal cord transection groupor control group, the difference was statistically significant.Conclusion The spinal nerve which dominate bladder will degenerate slightly after spinal cord transection and it will degenerate obviously after spinal cord injury. Part threeA new suprapubic catheter without urine drainage bagObjective To design a new suprapubic catheter without urine drainage bag.Methods The new suprapubic catheter includes the tube wall, fixed plate, theballoon, the injection valve and the piston valve. It is applicable to patients which needlong-term bladder catheterization, especially to patients with bladder dysfunction butremain the function of the limbs.Results The design has obtained national invention patent.Conclusion The design is expected for clinical application, and provide a newcatheter selection for the patients accepting cystostomy.