骶神经根电刺激排尿中完全性后根去传入的替代方法

目的 探讨脊髓损伤病人进行骶神经根电刺激排尿时膀胱完全性去传入手术的替代方法。方法 １０条犬经Ｔ１０平面截瘫后,按Ｌ７～Ｓ３前后根切断程度和组合方式的不同分成４组,观察术中神经根电刺激时膀胱尿道的压力变化和术后膀胱压力容积曲线（ＣＭＧ）变化。结果 保留２侧Ｓ１前后根完整,电刺激同平面Ｓ１的总根或后根,膀胱尿道的压力反应相同;切断两侧Ｓ１前根,刺激同平面的Ｓ１后根,膀胱尿道的压力反应显著降低,仅为前     

利用正常腰骶神经根重建膀胱反射弧对下肢功能影响的临床观察

目的 观察利用正常腰骶神经根重建膀胱反射弧对切断神经根所支配区域运动功能的影响.方法 对9例脊髓损伤后膀胱功能障碍而下肢运动功能仍存在的患者,利用其功能健存的脊髓节段的单根神经根前根中枢端,吻接支配膀胱的S2(或S3)神经根前根周围端,建立新的膀胱人工反射弧以重建膀胱功能,术后观察下肢相应区域运动功能变化.结果 9例中4例S1神经前根切断,术后主观感觉小腿肌力稍有下降,查体踝跖屈肌力约下降半级,3个月后随访肌力恢复;2例L3神经前根切断,2例L4神经前根切断,1例L5神经前根切断,术后肌力均无明显影响.结论 切断单一腰骶神经根前根对下肢运动功能无明显影响.     

建立人工膀胱反射弧治疗脊髓损伤后弛缓性膀胱的实验研究

目的探讨利用脊髓损伤平面以上健存的体反射重建人工膀胱反射弧,恢复脊髓损伤(spinalcordinjury,SCI)后膀胱排尿功能。方法1岁龄雄性Beegle犬8只,体重9.5±2.0kg。取后正中切口暴露L4～S3的棘突和椎板,全椎板切除后暴露硬膜和脊神经根,在硬膜外初步分离和确认L6和S2前根。确定犬左侧为实验侧,将左侧L6与S2前根分别在穿神经根管处切断,切开硬膜囊,从硬膜外L6和S2前根追溯硬膜内神经根,在显微镜下将L6和S2前根在硬膜内吻合。经一段时间轴突再生后,建立“膝腱-脊髓中枢-膀胱”人工反射弧。神经缝合术后8个月,在破坏S1～S4脊髓节段前后,分别进行神经电生理、膀胱肌电图及尿流动力学等远期功能观察。结果术后8个月,3只犬死亡,3只犬未能分离出吻合的神经,无实验结果。余2只犬均获得满意结果,定为1号和2号犬,进行观察。刺激(连续刺激强度200μV,刺激间隔为5ms)截瘫前和截瘫后2只犬左侧L6后根、神经吻合口,均可在吻合口远端记录到运动诱发电位,其波形和波幅相似;尿流动力学检查可见,当刺激开始时膀胱内压迅速上升,而腹内压增加幅度较小,刺激中止后膀胱内压迅速下降,证实膀胱内压升高主要是由逼尿肌收缩产生,电刺激左侧L6后根和吻合口膀胱内压升高值均可达到正常的60%左右。结论利用脊髓损伤平面以上健存的体反射重建膀胱反射通路是成功和有效的,体神经的运动支通过轴突再生能够长入自主神经的副交感神经纤维,并具有良好的传导运动兴奋的功能。     

腰骶神经吻合对自主性神经原性膀胱排尿功能影响的实验研究

目的:探讨通过腰骶神经吻合恢复或改善神经原性膀胱排尿功能的可行性.方法:10只家犬手术前先行尿流动力(包括膀胱容量、压力、顺应性)及肛门括约肌肌电图(EMG)测定,作为对照组数据.检测完后处死2只.取其S1、S2神经根,共8根作为对照组,行HE染色观察有髓和无髓神经纤维数量.其余8只犬为实验组,将L4与S1、L5与S2神经根分别端端吻合.术后4个月行尿流动力学测定,术后7个月再次行尿流动力学测定后处死动物,取L4、L5和S1、S2神经根吻合口段和骶神经干段行HE染色,观察有髓和无髓神经纤维数量.结果:术后4个月,实验组犬膀胱容量、顺应性和对照组比较明显增加(P<0.05);膀胱压力、肛门括约肌EMG的电压明显降低(P<0.05).术后7个月,实验组犬膀胱压力和肛门括约肌EMG的电压和对照组比较无明显降低(P>0.05);而膀胱容量和顺应性明显增加(P相似文献   

大鼠骶神经根对膀胱功能选择性支配的实验研究

目的：研究骶神经根对膀胱功能的选择性支配，为临床脊髓损伤(SCI）后的膀胱功能重建及建立实验性人工膀胱动物模型提供依据。方法：对10只SCI的SD大鼠进行硬膜外S1～S4骶神经根电刺激，记录膀胱神经丛动作电位和膀胱平滑肌复合肌肉动作电位变化，同时通过膀胱内插入测压管并经压力换能器记录膀胱内压的变化。结果：SD大鼠的S1～S4骶神经均参与膀胱神经功能支配，其中以S2骶神经最主要，S1、S3骶神经次之，S4骶神经的支配作用最小。结论：不同的骶神经根对膀胱平滑肌的支配效能不同，利用膀胱平滑肌的主要支配神经根进行人工电刺激排尿或通过神经吻合重建人工膀胱反射弧，对提高SCI后的膀胱排尿功能有一定的临床意义。     

不同动力神经根在膀胱功能重建时作用的比较

目的比较L5与S2前根作为动力神经根,对恢复膀胱的神经支配功能和重建排尿功能的作用。方法家犬5只,实验侧行L5-S2前根硬膜外交叉吻接,对照侧行S2-S2前根硬膜外自身吻接,术后1年分别电刺激实验侧和对照侧吻接口的中枢端,记录膀胱压和尿道压的变化。结果L5与S2前根都与膀胱逼尿肌和括约肌建立了神经联系。电刺激测压示:膀胱压实验侧(5.0±2.1)kPa与对照侧(4.6±1.8)kPa相比,差异无显著性意义(P=0.17);尿道压实验侧(4.2±1.7)kPa与对照侧(4.4±1.6)kPa相比,差异也无显著性意义(P=0.31)。结论脊髓损伤后膀胱因失神经支配而发生排尿功能障碍时,应用躯体运动性的L5前根与内脏副交感性的S2前根作为动力神经根来恢复膀胱神经的再支配和膀胱功能重建时,两者作用无明显区别。     

长时间电刺激后骶神经根的结构观察及临床意义

目的 观察长时间电刺激后骶神经根的结构变化，从而评价自制膀胱控制器植入术的安全性和远期疗效。方法 4只T10平面截瘫犬在双侧S2神经根上植入膀胱控制器的刺激电极，在实验结束前对截瘫犬进行连续电刺激，达到一定的累积刺激时间后取S2神经根进行光镜和电镜检查，观察长时间的电刺激对犬骶神经根有无损伤。结果 最长的累积刺激时间达162 h时，光镜显示骶神经前根结构无明显变化，后根神经纤维变性，骶神经根周围纤维结缔组织增生。电镜显示神经轴突正常，部分髓鞘有松散，粗面内质网和胶元分泌旺盛，提示纤维细胞增生。结论 自制膀胱控制器长期使用是安全和有效的。但是电镜下部分有髓神经纤维的髓鞘有松散仍应引起我们的注意。在使用膀胱控制器刺激排尿时，在达到尿液排空的目的后，排尿应尽可能选择低电压和低频率的电刺激模式，减小对骶神经根的刺激强度。     

膀胱控制器恢复截瘫犬膀胱功能的尿流动力学观察

目的:观察膀胱控制器重建截瘫犬排尿功能时的尿流动力学变化,评价膀胱控制器对截瘫犬排尿功能恢复的效果。方法:4只健康杂种犬经T10平面造成截瘫后,在双侧S2神经根上植入刺激电极并通过导线与皮下的接收器连接,通过体外发射器进行电刺激,同时作硬膜内S1～S3后根切断。术后每天进行电刺激,观察截瘫犬的排尿情况,并进行尿流动力学检查。结果:4只犬均获得电刺激人工控制下排尿,排尿量80～140ml/次,尿流动力学检测证实为刺激后排尿模式。结论:国产膀胱控制器结合骶部神经去传入能很好地重建截瘫犬膀胱的贮尿和排尿功能。     

骶神经根选择性切断治疗截瘫后痉挛性膀胱的实验及临床研究

目的观察高选择性骶神经根前根切断术治疗脊髓损伤后痉挛性膀胱的疗效,探讨其治疗机制、最佳手术方法及临床实际疗效. 方法雄性家犬12只,制成脊髓损伤后痉挛性膀胱模型,根据骶神经根切断方式:切断S2前根,切断S2前根 S3 1/2前根,切断S2、S3前根,完全切断S2～4神经根,依序分为A、B、C、D 4个组,通过尿动力学检测及电生理观察,分析比较骶神经根切断前、后各组功能性指标的变化,确定其最佳手术方案.临床治疗则根据实验结果,选择性切断脊髓损伤后痉挛性膀胱患者S2前根或 S3 1/2前根共32例.术前膀胱容量平均(120±30) ml,术前排尿量平均(100±30) ml,尿道压力平均为(120±20) cm H2O. 结果 4个组术后膀胱容量分别为:(150±50)、(180±50)、(230±50)、(400±50) ml;排尿量分别为:(130±30)、(180±50)、(100±50)、(50±30) ml.临床治疗32例,术后膀胱容量平均增加至410 ml左右,排尿量平均增加至350 ml左右,所有患者尿失禁消失.有13例获22个月远期随访,无复发. 结论高选择性骶神经根切断治疗脊髓损伤后痉挛性膀胱疗效显著,是一种值得研究、推广的新方法.     

大鼠脊髓损伤后膀胱生理反射弧重建的实验研究

目的 探讨利用截瘫平面以上健存的神经根,与硬脊膜内骶神经前后根分别吻合,建立人工膀胱反射通路,重建膀胱生理反射弧的有效性.方法 取3月龄雄性SD大鼠20只,体重250～300 g;右侧为实验侧,左侧为对照侧.将大鼠右侧L5前根近端与右侧S2前根远端,L5后根近端与S2后根远端在硬脊膜囊内分别行显微缝合,同时修复重建膀胱的感觉与运动功能,建立人工膀胱生理反射弧.左侧不作任何处理.于术后5个月,在破坏L6～S4节段脊髓制备完全性截瘫前后,分别进行电生理检查及膀胱内压测定.结果 18只大鼠存活至术后5个月,9只大鼠成功分离出吻合的神经根,获得实验结果.实验侧截瘫前后,单相方波(3mA、0.3ms)刺激S2后根吻合口远端,均可记录到膀胱神经丛动作电位,波幅分别为(0.10±0.02)mV和(0.11±0.03)mV,差异无统计学意义(P>0.05);串刺激(3mA、20Hz、5 s)S2后根,均可记录到膀胱平滑肌复合肌肉动作电位,其波幅分别为(0.11±0.02)mV和(0.11±0.03)mV,差异无统计学意义(P>0.05).刺激S2后根吻合口远端,经新建的人工膀胱反射弧引出的膀胱内压分别为(6.55±1.33)cmH2O和(6.11±2.01)cmH2O,差异无统计学意义(P>0.05).对照侧截瘫前刺激S2后根,引出的膀胱神经丛动作电位波幅为(0.144±0.02)mV,膀胱平滑肌复合肌肉动作电位波幅为(0.17±0.02)mV,膀胱内压为(10.77±1.78)cmH2O,均大于实验侧截瘫前后(P<0.01).而电刺激对照侧截瘫后S2后根,不能引出膀胱神经丛动作电位、平滑肌复合肌肉动作电位,膀胱内压无变化.结论 利用截瘫平面以上健存的神经根,通过与硬脊膜内骶神经前后根分别吻合,可建立完整的人工膀胱反射弧,有望实现截瘫患者自主性排尿.     

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.     

Bilateral S3 nerve stimulation, a minimally invasive alternative treatment for postoperative stress incontinence after implantation of an anterior root stimulator with posterior rhizotomy: a preliminary observation

STUDY DESIGN: A preliminary report. OBJECTIVES: Urinary stress incontinence following implantation of an anterior root stimulator and a posterior rhizotomy is a rare complication which is difficult to treat. It is seen in patients with an open bladder neck (T9-L2 lesion). An artificial urinary sphincter is a possible treatment for this condition but has a higher failure rate in patients with neurogenic bladder disease and could complicate micturition. SETTING: Ghent, Belgium. METHODS: A male paraplegic patient (T9, complete lesion) aged 36 was suffering from severe urinary incontinence due to detrusor hyperreflexia. Preoperatively the bladder neck was closed on cystography. Following implantation (6/95) of an intradural anterior root stimulator with posterior rhizotomy, severe urinary stress incontinence presented. Bilateral S3 foramen leads were implanted and connected to a pulse generator. RESULTS: The patient has been continent with continuous stimulation of both S3 roots for 4 years, and no fatigue of the levator muscles has been seen. Preoperative urodynamics are compared to results 3 years postoperatively. CONCLUSION: Bilateral S3 stimulation is a feasible and minimally invasive treatment of urinary stress incontinence following implantation of an anterior root stimulator.     

Selective activation of the sacral anterior roots for induction of bladder voiding

AIM: We investigated the efficacy of selective activation of the smaller diameter axons in the sacral anterior roots for electrically induced bladder voiding. MATERIALS AND METHODS: Acute experiments were conducted in five adult dogs. The anterior sacral roots S2 and S3 were implanted bilaterally with tripolar electrodes. Pressures were recorded from the bladder and from the proximal urethra and the external urethral sphincter. A detector and flow meter monitored fluid flow. A complete sacral dorsal rhizotomy was carried out. The effects of two types of pulse trains at 20 Hz were compared; quasitrapezoidal pulses (500 microsec with 500 microsec exponential decay) and interrupted rectangular (100 microsec, 2 sec on/2 sec off). Before rhizotomy, rectangular pulse trains (100 microsec) to activate all fibers were also applied. The experimental design was block randomized before and after rhizotomy. RESULTS: Quasitrapezoidal pulses showed block of sphincter activation with average minimum current for maximum suppression of 1.37 mA. All pulse types evoked average bladder pressures above the basal sphincter closure pressure. The pressure patterns in the proximal urethra closely followed the bladder pressures. Before dorsal rhizotomy, stimulation evoked a superadded increase in sphincter pressures with slow rise time. After rhizotomy, the sphincter pressure patterns followed the bladder pressures during selective activation and voiding occurred during stimulation with quasitrapezoidal trains and in between bursts with interrupted rectangular stimulation. CONCLUSIONS: Selective activation of sacral ventral roots combined with dorsal rhizotomy may provide a viable means of low-pressure continuous voiding in neurological impairment.     

Effect of acute selective sacral rhizotomy in cats on bladder and urethral function and the response to bethanechol chloride

Bladder and urethral responses to filling and to subcutaneous bethanechol are dependent upon intact sacral innervation. Acute selective sectioning of nerve roots in chloralose anesthetized cats was used to compare the sacral innervation requirements for the support of these responses. The detrusor was found to require primarily intact S2 roots although an S2 root on one side could, alone, subserve a weak, unsustained detrusor reflex. The urethral reaction to bladder filling required an afferent sacral pathway through either S1 or S2 roots. The sustained bladder response to subcutaneous bethanechol required greater sacral innervation than the detrusor reflex inasmuch as the S2 segment could subserve this response in only half the cases, and unilateral rhizotomy L7-S3 eliminated the response in half the cases. Both treatments, however, were compatible with a preserved detrusor reflex. The urethral constriction response to subcutaneous bethanechol required an intact sacral afferent pathway through either the S1 or S2 segments. In conclusion, the detrusor and urethral reflex responses to bladder filling and subcutaneous bethanechol require a certain amount of intact sacral innervation through S1 and S2 which is least for the detrusor reflex and greatest for the bladder response to subcutaneous bethanechol.     

The feasibility study of extradural nerve anastomosis technique for canine bladder reinnervation after spinal cord injury

Objective: Intradural nerve anastomosis for bladder innervation has been demonstrated to be useful. However, its clinical application remains limited because of the complex surgery, its complications and extensive bony destruction. The purpose of the current study was to demonstrate the feasibility of extradural spinal root anastomosis for bladder innervation in canines.

Methods: Ten beagle dogs were used. The length of the extradural segment of the nerve root, upper nerve root outlet (the point at which it emerges from the spinal dura mater) to S2 (dS2), the S3 (dS3) nerve root outlet distance, and the diameters of the extradural spinal roots were measured. The numbers of nerve fibers from L6 to S3 ventral roots were calculated using immunohistochemical staining.

Results: The extradural spinal roots could be divided into a ventral root (VR) and a dorsal root (DR) before the ganglionic enlargement of the dorsal root, and the extradural motor nerve roots situate ventrally to their corresponding sensory nerve roots. The extradural nerve root lengths of S1 and parts of L7 were longer than the corresponding dS2. The numbers of nerve and motor nerve fibers, and the diameters of extradural nerve roots, were gradually descending from L6 to S3.

Conclusion: The S1 VRs and parts of the L7 VRs can be extradurally anastomosed to the S2 nerves without tension. A nerve graft was needed for extradural anastomosis of L6 VRs and parts of L7 VRs to S2 VRs. This study demonstrated the feasibility of extradural spinal nerve anastomosis for treating neurogenic bladder in canines.     

Results of the Treatment of Neurogenic Bladder Dysfunction in Spinal Cord Injury by Sacral Posterior Root Rhizotomy and Anterior Sacral Root Stimulation

Purpose

We evaluated the results of treatment of neurogenic bladder dysfunction in spinal cord injury by sacral posterior root rhizotomy and anterior sacral root stimulation using the Finetech-Brindley stimulator.**Finetech Ltd., Welwyn Garden City, Hertfordshire, England.

Materials and Methods

In 52 patients with spinal cord lesions and urological problems due to hyperreflexia of the bladder complete posterior sacral root rhizotomy was performed and a Finetech-Brindley sacral anterior root stimulator was implanted. All patients were evaluated and followed with a strict protocol. A minimal 6-month followup is available in 47 cases.

Results

Complete continence was achieved in 43 of the 47 patients with 6 months of followup. A significant increase in bladder capacity was attained in all patients. Residual urine significantly decreased, resulting in a decreased incidence of urinary tract infections. In 2 patients upper tract dilatation resolved. In 3 patients rhizotomy was incomplete and higher sectioning of the roots was necessary. One implant had to be removed because of infection.

Conclusions

The treatment of neurogenic bladder dysfunction in spinal cord injury by anterior sacral root stimulation with the Finetech-Brindley stimulator in combination with sacral posterior root rhizotomy provides excellent results with limited morbidity.     

Spinal implants of olfactory ensheathing cells promote axon regeneration and bladder activity after bilateral lumbosacral dorsal rhizotomy in the adult rat

PURPOSE: We performed spinal implantation of olfactory ensheathing cells to demonstrate dorsal root afferent regeneration as well as bladder activity restoration after lumbosacral L6 to S2 rhizotomy. MATERIALS AND METHODS: Spinal segments receiving bladder innervation, usually L6, S1 and S2, were identified by bipolar stimulation of the ventral roots. Bilateral section of the identified dorsal roots L6 to S2 was performed in 18 male Wistar rats. Immediately after rhizotomy olfactory ensheathing cells or vehicle was unilaterally injected in the vicinity of the sacral parasympathetic nucleus in 9 rats each using a glass micropipette and air pulse system. The severed roots were reattached to the cord with fibrin glue and the animals recovered under antibiotic prophylaxis. RESULTS: Anatomical regeneration of bladder wall primary afferents was demonstrated by the presence of labeled wheat germ agglutinin-horseradish peroxidase fibers in the dorsal horn and sacral parasympathetic nucleus in 8 of 9 cases of olfactory ensheathing cell implantation but not in the 9 controls injected with vehicle. One week after surgery all rats had an atonic bladder on cystometrography. At 6 weeks 8 of the 9 olfactory ensheathing cell implanted rats had recovered bladder activity. No recovery was observed in controls, in which vehicle was injected instead of olfactory ensheathing cells. CONCLUSIONS: Regenerated primary afferent fibers from the bladder project to the sacral parasympathetic nucleus, where they presumably form synapses mediating the recovery of bladder activity. Thus, olfactory ensheathing cell implants in the adult rat promote sensory axon regeneration, target reinnervation and bladder activity restoration.     

人工反射弧重建膀胱功能动物模型的建立

目的 :建立犬“膝腱 脊髓 膀胱”反射弧重建膀胱功能的动物模型 ,作为实验研究人工膀胱反射弧的基础。方法 :家犬 5条 ,行硬膜外L5 S2前根交叉吻接 ,饲养 1年后刺激反射弧并记录膀胱压和尿道压变化。结果 :5只家犬“膝腱 脊髓 膀胱”反射弧均成功建立 ,刺激反射弧时膀胱压和尿道压都有升高。结论 :通过硬膜外L5 S2前根交叉吻接可以更有效地建立人工反射弧重建膀胱功能的动物实验模型。