Intercostal nerve transfer in brachial plexus injuries: An experimental study

Eighteen adult mongrel dogs underwent unilateral surgical disruption of the brachial plexus. Twelve animals (Group I) had as a second-stage procedure transfer of T4 and T5 intercostal nerves and their accompanying vascular bundles to the distal musculocutaneous nerve stump. Six animals (Group II) had restoration of musculocutaneous nerve continuity with conventional interpositional sural nerve cable grafts. Group I animals demonstrated significantly better electromyographic evidence of reinnervation and, comparing appearance and weight of operated and unoperated biceps muscles at the time of animal sacrifice, maintained greater gross weight and more normal overall appearance of muscle. Histologic study of muscle tissue showed no significant difference between the two groups whereas musculocutaneous nerve histology distal to all anastomoses revealed less fibrous tissue and a greater number of healthy-appearing axons in Group I. It is concluded that vascularized intercostal nerve transfer as performed in this study has theoretical advantages over conventional nonvascularized intercostal nerve transfer but additional investigation is required to make this determination. The superiority of vascularized intercostal nerve transfers over conventional interpositional sural nerve cable grafts has been demonstrated.     

周围神经侧侧缝合法的实验研究

目的 提出一种修复周围神经操作的新方法－－侧侧缝合法,并对侧侧缝合后神经的再生模式进行初步研究。方法 选用ＳＤ雄性大鼠１２只,双下肢随机分为实验侧和对照侧。实验侧：将腓总神经在大腿下１／３处切断,断端结扎后将其远端与相邻胫神经干适当松解后靠拢,纵行切开两神经相邻侧面的神经外膜、束膜长约０．５ｃｍ,至部分神经纤维外露。紧密对合两切开面后缝合束膜、外腊。对照侧：腓总神经在相同部位切除０．５ｃｍ,至部分     

Phrenic nerve transfer in the treatment of brachial plexus avulsion: an experimental study of nerve regeneration and muscle morphology in rats

The regeneration of motor and sensory neurons and the morphological changes of the target muscle after phrenic nerve transfer were investigated in adult rats. Six months following nerve transfer, 326.0 +/- 16.31 phrenic motoneurons regenerated into musculocutaneous nerve, which is not different from the normal number of phrenic motoneurons. The regenerated motoneurons exhibited a 14% nonsignificant hypertrophy. Of the dorsal root ganglia (DRG) neurons, 255.8 +/- 45.26 regenerated, which was significantly lower than the number of normal phrenic DRG neurons. The regenerated phrenic DRG neurons showed a 24% close-to-significant atrophy. The target muscle fiber morphology changed considerably after reinnervation. The present results suggest that the phrenic nerve has very good regenerative ability in terms of its motoneurons and a relatively insufficient sensory neuronal regeneration.     

颈7神经移位修复臂丛撕脱伤两根受损神经实验研究

目的 探索利用颈,神经移位同时修复两根受损神经的可行性. 方法 建立大鼠颈,移位同时修复两根受损神经的动物模型,并与传统C7单组移位术进行神经再生疗效的比较. 结果 各项指标显示:术后早期(2～6周)颈,修复两根神经组神经再生效果劣于同时间段单组移位组,但随观察时间延长,术后8周起各项再生指标逐渐接近单组移位组和正常对照组,至12周,多数指标差异已无统计学意义. 结论 大鼠颈7神经根能提供足够再生纤维同时恢复两根受损神经功能.     

Patterns of injury to the terminal branches of the brachial plexus. The place for early exploration

Non-operative management has frequently been adopted for closed injuries of the infraclavicular brachial plexus and its branches in the belief that spontaneous recovery is likely to occur, and surgical exploration is performed only if recovery has not occurred in the expected time. This paper correlates the clinical and electrophysiological features with the operative findings in six patients with such injuries. The axillary nerve was ruptured in all six patients, the musculocutaneous nerve in two and the radial nerve in two. When the muscles supplied by a branch of the plexus were denervated, the differentiation between rupture of that branch and a lesion in continuity could only be made by surgical exploration, which should be performed as soon as other injuries permit.     

维持肢体正常的运动感觉功能所需最少神经根数的实验研究

目的 研究臂丛神经根单发断，２根切断（不同方式联合）及３根切断后对肢体的影响，为治疗臂丛根性撕脱伤寻找更多的潜在移位神经，方法 ２５２只ＳＤ大鼠随机分为１３组：（１）第１－５组（单根神经根切断组）；每组１２只大鼠。分别切断Ｃ５－８Ｔ１各神经根；（２）第６－１２组（２根神经根切断组）；每组２４只大鼠。分别切断相邻及不相邻２根神经根，即Ｃ５，６，Ｃ６，７，Ｃ７，８，Ｃ８Ｔ１，Ｃ５，７，Ｃ６，８和Ｃ７Ｔ     

Contemporary treatment of peripheral nerve and brachial plexus lesions

Summary The paper outlines modern microsurgical techniques utilized in the repair of injured peripheral motor and sensory neurons. The diagnostic evaluation and its timing, which depend on the level and the extent of the lesion, are proposed. The author stresses the need during the operation for close monitoring, which is a prerequisite of proper coaptation of the severed nerve structures. A technically perfect microsurgical repair provides optimal conditions for regeneration of the divided peripheral nerves and/or brachial plexus. The repair of avulsion injuries of the brachial plexus still poses many technical problems; the author proposes the use of intercostal nerves as new sources for grafts. Pain, which is one of the major problems occurring with peripheral nerve injuries, especially with lesions to the brachial plexus, is not dealt with in detail. The author maintains that the contemporary treatment of peripheral nerve injuries as a rule yields good results, while this is not yet true of the management of brachial plexus lesions.     

周围神经端侧吻合后神经再生的研究

目的研究周围神经端侧吻合后远端神经的再生及其临床应用价值。方法选用３７只Ｗｉｓｔａｒ大鼠，分成Ａ、Ｂ两组。Ａ组：切断腓神经，在邻近的胫神经干外膜上开一１ｍｍ小窗，将腓神经远端吻合到胫神经干侧方开窗处。Ｂ组：切断腓神经后，在胫神经干和远侧腓神经干外膜上各开一小窗，取对侧相应的腓神经以端侧吻合的方式桥接于胫、腓神经干两窗之间。两组分别于术后４、８、１２周取材，作神经组织学、电镜及图像分析仪检测：（１）神经再生的数量和质量；（２）定性定量观察神经再生情况；（３）再生神经的数目、密度及截面积。结果直接端侧吻合或神经桥接移植的端侧吻合，均可使神经再生，且再生纤维的质量与端端吻合组（对照组）无显著性差异（Ｐ＞０．０５）；对被吻合神经－胫神经的功能亦无影响。结论神经端侧吻合可作为神经损伤后一种新的修复方法     

Concepts of nerve regeneration and repair applied to brachial plexus reconstruction

Brachial plexus injury is a serious condition that usually affects young adults. Progress in brachial plexus repair is intimately related to peripheral nerve surgery, and depends on clinical and experimental studies. We review the rat brachial plexus as an experimental model, together with its behavioral evaluation. Techniques to repair nerves, such as neurolysis, nerve coaptation, nerve grafting, nerve transfer, fascicular transfer, direct muscle neurotization, and end-to-side neurorraphy, are discussed in light of the authors' experimental studies. Intradural repair of the brachial plexus by graft implants into the spinal cord and motor rootlet transfer offer new possibilities in brachial plexus reconstruction. The clinical experience of intradural repair is presented. Surgical planning in root rupture or avulsion is proposed. In total avulsion, the authors are in favor of the reconstruction of thoraco-brachial and abdomino-antebrachial grasping, and on the transfer of the brachialis muscle to the wrist extensors if it is reinnervated. Surgical treatment of painful conditions and new drugs are also discussed.     

Injuries of the terminal branches of the infraclavicular brachial plexus: patterns of injury, management and outcome

We reviewed 101 patients with injuries of the terminal branches of the infraclavicular brachial plexus sustained between 1997 and 2009. Four patterns of injury were identified: 1) anterior glenohumeral dislocation (n = 55), in which the axillary and ulnar nerves were most commonly injured, but the axillary nerve was ruptured in only two patients (3.6%); 2) axillary nerve injury, with or without injury to other nerves, in the absence of dislocation of the shoulder (n = 20): these had a similar pattern of nerve involvement to those with a known dislocation, but the axillary nerve was ruptured in 14 patients (70%); 3) displaced proximal humeral fracture (n = 15), in which nerve injury resulted from medial displacement of the humeral shaft: the fracture was surgically reduced in 13 patients; and 4) hyperextension of the arm (n = 11): these were characterised by disruption of the musculocutaneous nerve. There was variable involvement of the median and radial nerves with the ulnar nerve being least affected. Surgical intervention is not needed in most cases of infraclavicular injury associated with dislocation of the shoulder. Early exploration of the nerves should be considered in patients with an axillary nerve palsy without dislocation of the shoulder and for musculocutaneous nerve palsy with median and/or radial nerve palsy. Urgent operation is needed in cases of nerve injury resulting from fracture of the humeral neck to relieve pressure on nerves.     

Peripheral nerve autografts to the injured spinal cord of the rat: An experimental model for the study of spinal cord regeneration

Summary Regenerated central axons have been shown experimentally to penetrate in peripheral nerve segments transplanted into the spinal cord (SC). However, if the nerves are transplanted between the stumps of the transected SC regeneration is impaired by local cavitation and scarring.Our experiment was designed to study whether nerve grafts bridging a severe transverse SC lesion might provide to central regenerating axons a pathway to by-pass the lesion. To this purpose, 2 segments of autologous peripheral nerves were inserted through small dural openings into dorsal longitudinal myelotomies rostral and caudal to a transverse SC lesion in rats. Eighteen weeks after transplantation a large number of well myelinated fibres filled the grafted nerves. Only a few of these fibres, however, could be followed into the SC; they were located in the outer layers of the dorsal white matter. The problems regarding the origin and destination of these fibres are discussed.     

Microsurgical management of old injuries of the peripheral nerve and brachial plexus

A prospective study was carried out in patients suffering from old peripheral nerve and brachial plexus injuries to attempt to validate that functional improvement was possible after microsurgical management. Fifty patients underwent operative procedures, of whom 35 were peripheral-nerve injury cases, from 1.2 to 50 years after injury, and 15 were brachial-plexus injury cases, from 1.2 to 12 years after injury. The patients were treated by external and interfascicular neurolysis and/or autogenous nerve grafts. In cases of preganglionic nerve injury, neurotization from C3, C4 roots was done for reinnervation of trunks or cords. During external and interfascicular neurolysis in 19 of the 35 peripheral-nerve injuries, significant improvement was found in amplitude (p = 0.0001) and latency (p = 0.01) of compound muscle action potentials (CMAPs) at the end of the surgery, compared to the onset of surgery. Twenty (57 percent) of the 35 showed functional motor improvement up to M4-or M4. Electrophysiologic analysis of amplitude of CMAPs 1 year after surgery showed statistically significant improvement (p = 0.0003). Five (33 percent) of the 15 patients with upper brachial-plexus injuries showed functional motor improvement up to M4-(active movements against gravity and slight resistance) or M4 (active movements against gravity and moderate resistance) after surgery and of these, 11 also had lower brachial-plexus injuries, with four (36 percent) showing antigravity function M3 (active movement against gravity). Statistical analysis of recruitment 1 year after surgery demonstrated the appearance of or significant voluntary muscle activity in 45 percent of the muscles. Intraoperative electrophysiologic findings after external and interfascicular neurolysis confirmed that the viability of nerve tissue is of longer duration than previously considered. This study suggests that the use of microsurgical techniques results in the functional improvement of patients suffering from old injuries of the peripheral nerve and brachial plexus.     

Effect of ligating peripheral branches on facial nerve regeneration

Bilateral transection and reanastomosis of the main trunk of the facial nerve was performed on 18 rats. On one side of each rat, all peripheral branches except the mandibular branch were ligated with silk suture and divided distal to the ligatures. Axon counts after 1, 3, and 6 months showed a statistically significant increase in the number of axons in both the mandibular branch and the main trunk on the side with the peripheral ligation. These data indicate that peripheral branch ligation is a useful adjunct in facial nerve rehabilitation.     

Ciliary neurotrophic factor for acceleration of peripheral nerve regeneration: an experimental study

The objective of this study was to investigate the effect of topically administrated ciliary neurotrophic factor (CNTF) on peripheral nerve regeneration. Sixty-eight Sprague Dawley rats underwent a unilateral sciatic nerve transection and silicon tubulization, with a 10-mm gap between the proximal and distal nerve stumps. Recombinant human CNTF (1 mg/kg) was injected into the rats of the experimental group, while normal saline was injected into the control group animals. Electrophysiologic and histologic studies, including nerve morphometry and electron microscopic observation, were performed at 1, 3, and 4 months postoperatively. HRP tracing was carried out at 3 months postoperatively to label spinal-cord, ventral-horn, and dorsal-root ganglia. The results revealed that CNTF-treated animals showed a higher motor nerve conduction velocity of the sciatic nerve and a higher muscle action potential amplitude of the anterior tibial muscle, compared to the controls ( p < 0.01). Nerves repaired with CNTF had larger axon diameter, greater number of axons, and more advanced myelination ( p < 0.05). More HRP-labeled motor neurons were also found in the ventral horns of CNTF-treated animals. These results indicate that topical application of CNTF to the injury site potentiates motor nerve axonal regrowth and axon maturation during peripheral nerve regeneration.     

联合尺神经束支和臂丛外神经移位治疗臂丛损伤

目的 观察联合尺神经束支和臂丛外神经移位治疗臂丛损伤的临床效果.方法 臂丛损伤6例,其中单纯上干损伤4例;上中干为主,合并下干部分损伤2例.伤后平均2.8个月接受手术.术式包括尺神经部分束支转位至肌皮神经肱二头肌肌支,膈神经或者副神经斜方肌支转位至肩胛上神经,桡神经肱三头肌长头肌支转位修复腋神经肌支.用肱二头肌、岗上肌和三角肌肌力,肩外展和上举角度,尺神经功能损失等指标对手术方式和效果进行评估.结果 6例中5例得到随访,平均随访时间18个月,肱二头肌均在术后3～4个月开始恢复肌力.随访时间18个月以上的4例屈肘M_4~+～M_5;随访时间4个月的1例屈肘M_3~+.其中3例行外展功能重建,单用膈神经修复的病例上臂可上举至180°,外展肌力M_4~+;联合副神经和肱三头肌长头肌支修复的病例上肢可外展90°,肌力M_4~-;单用副神经修复的病例上肢可外展80°,肌力M_3~+.3例手部握持力与术前相同,2例增强.4例手部尺神经供区功能无明显影响,1例小指掌侧皮肤感觉减退,第一骨间背侧肌萎缩.结论 尺神经部分束支转位修复肱二头肌支可以有效的恢复臂丛损伤后屈肘功能;用膈神经修复肩胛上神经可能取得更好的肩外展和上举效果;本组臂丛下干部分损伤的病例受伤均在3个月内,采用此术式同样恢复了肱二头肌功能,未加重原有的手功能障碍.     

供体神经端-侧缝合治疗臂丛神经损伤的比较研究

目的 比较不同供体神经端-侧缝合修复臂丛神经损伤效果的差异.方法 SD大鼠90只,随机分为5组,切断右侧颈5、6神经根,模拟臂丛上干损伤,分别以膈神经及同侧颈7神经根作为供体神经,按照端-端和端-侧两种缝合方式修复患侧肌皮神经,另一组作为对照组,不予修复.各组分别于术后1、2、3个月取材,作神经行为学评分、电生理及病理组织学检测.结果 术后3个月,以不同供体神经行端-侧缝合组均有明显神经再生现象,但效果不及对应的端-端缝合组(P＜0.05).同侧颈7神经根端-侧缝合组,其行为学评分、肱二头肌复合肌肉动作电位、肌肉和神经组织学检测为各修复组最低,差异有统计学意义(P＜0.05).结论 在大鼠上干损伤模型中,采用不同的供体神经进行端-侧缝合效果存在差异,膈神经与同侧颈7神经相比,是端-侧缝合相对较好的供体神经;利用神经端-侧缝合修复臂丛神经损伤的效果尚不能达到与端-端缝合相同的效果,临床使用需掌握严格的适应证.