Restoration Of Bladder Function Through End-to-side Neurorrhaphy Of Lumbar And Sacral Roots In Cats

Part ? An anatomy study of nerves controlling bladder in catsObjective: To investigate the constitution and anatomy features of nerves controlling bladder in cats,thus providing anatomic basis for reconstruction of bladder function using nerve transfer.Methods: Fifteen adult cats including 10 female and 5 male cats were studied.Bilateral extradural nerve root including lumbar and sacral roots were exposed carefully under the guidance of surgical microscope after hemilaminectomy with rongeur.Then,the bipolar electrode stimulated L7,S1,S2,and S3 sequentially and bilaterally with the stimulation parameter: 2m A electricity,20 Hz stimulation frequency and 0.2ms impulse width;the BL-420 F biomedical apparatus was utilized to record the bladder contraction.Moreover,we measured the distance between L6 and L7,L7 and S1,S1 and S2 bilaterally,and the diameter of L7 and S1 bilaterally.Results: When stimulating S1 and S3,the contraction curve slowly climbed to the highest point,while stimulating the S2,the contraction curve rapidly climbed to the plateau and declined to the baseline after the micturition.Vesical pressure(VP)induced by left S1,S2 and S3 were 4.660±3.692 cm H2 O,36.85±13.84 cm H2 O,and 8.653±3.856 cm H2 O respectively;meanwhile,VP induced by right S1,S2 and S3 were 4.727±4.099 cm H2 O,35.25±14.89 cm H2 O,and 8.473±3.870 cm H2 O.The VP induced by S2 was significantly higher than that of S1 and S3(P<0.05).Furthermore,the distance of L6-L7,L7-S1,and S1-S2 in the left were 12.86±1.903 mm,6.831±1.030 mm,and 7.373±1.397 mm separately;the distance of L6-L7,L7-S1,and S1-S2 in the right were 12.99±1.805 mm,6.863±1.153 mm,and 7.495±1.371 mm.The distance of L6-L7 was markedly longer than L7-S1(P<0.0001).The diameter of left L7 and S1 were 2.963±0.4163 mm and 1.699±0.4289 mm;the diameter of left L7 and S1 were 3.025±0.4463 mm?1.725±0.4122 mm.The diameter of L7 was distinctly larger that S1(P<0.0001).Conclusions: The S1,S2,and S3 together control the bladder in cats,among which the S2 exhibits the most important role.The distance of L6-L7 was markedly longer than L7-S1.The diameter of L7 was distinctly bigger than S1Part ? Reconstruction of bladder efferent pathway through end-to-side neurorrhaphy of lumbar and sacral root in catsObjective: To evaluate the regenerative nerve morphologically and investigate the reconstructed efferent pathway after end-to-side neurorrhaphy of lumbar and sacral root.Methods: Nine female and six male adult cats were included in this study.The left side in every cat was treated as the self-control group,while the right side received the nerve transfer operation.The distal stump of sacral 2 ventral root(S2VR)was sutured to the lateral face of the lumbar 7 ventral root(L7VR)through end-to-side intradural microanastomosis;the proximal stump of S2 VR was ligated in case of regeneration.Then,the dural was closed in a continuous way;the residual S1 and S3 were extradural transected to decentralize the bladder unilaterally.10 months postoperatively,FG was injected into bladder wall for retrograde nerve tracing;morphological examination of recipient nerve was conducted.Results: FG labeled neurons were observed in the right ventral horn of L7 of cats by retrograde nerve tracing,and the number of FG labeled neurons were 21.5±6.5;however,in the left ventral horn of L7,no FG labeled neurons were found.Morphological examination of nerve revealed that apparent nerve regeneration and the number of myelinated axons in normal and receipt nerve was 825.2±114.1 and 846.4±261.4 respectively(P>0.05).Conclusions: These results indicated that nerve regeneration could be achieved,and new bladder efferent pathway was reconstructed after end-to-side neurorrhaphy of lumbar and sacral root.Part ? Restoration of bladder function through end-to-side neurorrhaphy of lumbar and sacral root in catsObjective: To investigate the bladder functional restoration by applying neurophysiological techniques and acetylcholinesterase staining.Methods: 10 months postoperatively,2 weeks after injection of FG in bladder wall,the anastomosis was exposed carefully and stimulated at the proximal;vesical pressure(VP)and electromyography of pelvic floor muscle were recorded.The acetylcholinesterase staining was performed by acetyl cholinesterase staining solution kit.Results: Functional electrical stimulation revealed that all 15 cats had varying degrees of functional restoration,of which 8 exhibited higher VP and 7 exhibited lower VP compared with the self-control side.VP induced by the operation side was 39.5±16.19 cm H2O;VP induced by the self-control side was 41.97±9.288 cm H2O;there was no differences between the two groups(P>0.05).however,10 out of 15 cats demonstrated reduced electromyography.The acetylcholinesterase staining showed brown precipitate within the axon.Conclusions: End-to-side neurorrhaphy of lumbar and sacral root in cats could restore bladder function and might produced synergic bladder detrusor and sphincter.Part ? Effect of end-to side neurorrhaphy of lumbar and sacral root on donor nerveObjective: To investigate the effect of end-to side neurorrhaphy of lumbar and sacral root on lumbar root in catsMethods: 10 months postoperatively,the proximal and distal portion of lumbar root were obtained to perform toluidine blue and axons counting.Wet weight of bilateral extensor digitorum longus(EDL)muscles of cats was weighted.Results: The number of myelinated axons of L7 VR proximal and distal to coaptation site were 3613±840.3 and 3614±825.5.Moreover,wet weight of bilateral EDL muscles was 6.547±1.161 g and 6.523±1.143 g respectively.No differences were observed regarding the myelinated axons and EDL wet weight.Conclusions: End-to-side neurorrhaphy of lumbar and sacral root had no deleterious effect on donor nerve in cats.