Susceptibility of the superficial sensory branch of the radial nerve to form painful neuromas

The superficial sensory branch of the radial nerve appears prone to develop painful neuromas out of proportion to its likelihood for injury. Based on cadaver dissections and intraoperative observations, an anatomical mechanism for this "predisposition" is suggested. Exit of this nerve beneath dense fascia and the tendons of brachioradialis and extensor carpi radialis longus provide a proximal tethering against which tension develops as the distal fixation point (neuroma) is pulled through the long excursion of wrist arc of motion. This long excursion and proximal tethering are not present anatomically for the dorsal cutaneous branch of the ulnar nerve nor the palmar cutaneous branch of the median nerve.     

Ulnar nerve repair by end-to-side neurorrhaphy on the median nerve with interposition of a vein: an experimental study

Our study used a rat animal model to verify that Schwann cell migration, collateral axonal sprouting, and regeneration were not hindered by interposition of a 10-mm vein segment between the distal stump of the transected ulnar nerve and the donor median nerve in end-to-side reconstruction. Reconstructed nerves were withdrawn at 7, 14, 30, and 60 days after surgery, then analyzed by confocal laser microscopy after immunolabeling with anti-neurofilament-200 kD (an axonal marker) and anti-S100 (a glial marker) antibodies. Results are reported at 7, 14, 30, and 60 days after surgery. Our observations indicate that chemotactic factors that stimulate end-to-side nerve regeneration can exert their action at this distance. These findings suggest a possible clinical application for this surgical technique in cases when the severed nerve stump is far from the potential donor nerve.     

Dorsal branches of superficial radial nerve: an anatomic study with potential clinical applications

An anatomical study was performed to assess the course of the dorsal branches of superficial radial nerve and to investigate potential clinical applications in hand surgery. Eight upper extremities were dissected, using an operating microscope. All branching points of the superficial radial nerve were noted and the distances from the radial styloid process were recorded. Their proximity to neighboring vascular structures was noted. The superficial branches of the radial nerve can vascularize axial neurofasciocutaneous flaps via their paraneural arterial network. In addition, various reverse neurofasciocutaneous flaps may be harvested, based on dorsal branches of the superficial radial nerve. The nerve can be anastomosed with a suitable nerve in the recipient area. The dorsal branches of the superficial radial nerve can easily be added to the reverse first dorsal metacarpal artery flap and other reverse dorsal metacarpal artery flaps, thus making it possible to form a sensate flap. These branches may be anastomosed with nerves in the recipient site, such as dorsal branches of digital nerve stump, without significant donor site morbidity. A free sensate first dorsal artery flap can be prepared with a combination of dorsal branches of the superficial radial nerve and used with the same indications as a free digital artery flap. It has some advantages over the free digital artery flap, because the main neurovascular structures of the finger are kept intact. Finally, a dorsal nerve branch which accompanies the first dorsal metacarpal artery may be harvested with this artery and a subcutaneous dorsal vein as vascularized nerve graft. It can be used to repair a digital nerve defect in dense scar tissue. Received: 3 January 2000     

指神经深低温冷冻法预防和治疗痛性神经瘤

我院自1996年5月用指神经深低温冷冻法预防和治疗痛性神经瘤34例42指,获得满意疗效,报道如下。1　材料与方法1.1　病例资料　本组34例42指。男28例,女6例,年龄18～65岁。食指12个,中指8个,环指7个,小指15个。一期26例34指,受伤时间05～10ｈ,二期8例8指。均为外伤性截指后残端痛,病史为2～10个月,均有明显的自发性疼痛,疼痛呈触电样,触痛区有明显感觉异常。1.2　手术方法　一期患者急诊行清创术,沿神经体表投影处纵行切开皮肤05ｃｍ,游离两侧神经,锐性切除神经断端;二期患者根据神经瘤所在部位选择切口,显露整个神经瘤,完整切除神经瘤,直至显…     

IGF-I and end-to-side nerve repair: a dose-response study

End-to-side nerve repair allows for target-muscle reinnervation, with simultaneous preservation of donor-nerve function. Local administration of insulin-like growth factor-I (IGF-I) has been shown to increase the rate of axon regeneration in crush-injured and freeze-injured rat sciatic nerve. The purpose of the current project was to determine the effects of IGF-I in a rat model of end-to-side nerve repair. The left musculocutaneous nerve of 18 adult male Sprague-Dawley rats was fully transected to induce biceps-muscle paralysis. The distal stump of the musculocutaneous nerve was then coapted by end-to-side neurorrhaphy through a perineurial window to the ipsilateral median nerve. All animals were randomly assigned to three groups: Group A received 100 microg/ml IGF-I; Group B received 50 microg/ml IGF-I; and control Group C received 10 mM acetic acid vehicle solution. Infusions were regulated by the Alzet model 2004 mini-osmotic pump, with an attached catheter directed at the coaptation site. Weekly postoperative behavioral evaluations revealed significantly increased functional return over control in both experimental groups as early as 3 weeks. After 28 days, histology evaluations revealed statistically significantly higher musculocutaneous nerve axon counts and myelin thickness/axon diameter ratios in both experimental groups vs. controls. The three groups were not significantly different in motor endplate counts of the biceps muscle. Groups A and B were not significantly different in all parameters tested. This study suggests that local infusion of IGF-I may expedite the functional recovery of a paralyzed muscle, by increasing the rate of axon regeneration through an end-to-side nerve graft.     

Axonal supercharging technique using reverse end-to-side neurorrhaphy in peripheral nerve repair: an experimental study in the rat model

OBJECT: In an attempt to improve peripheral nerve repair, the influence of the addition of reverse end-to-side neurorrhaphy for an injured peripheral nerve was investigated in the rat sciatic nerve transection model. METHODS: Twelve Sprague-Dawley rats were divided into two groups (six rats in each group). In Group I, the right sciatic nerve was cut at a point distal to the gluteal notch and repaired using end-to-end neurorrhaphy with four 10-0 nylon epineurial sutures. In Group II, after performing the same procedure as in Group I, the left sciatic nerve was cut distally and passed through a subcutaneous tunnel to the right side. The proximal stump of the left sciatic nerve was coapted to the epineurial window of the right sciatic nerve distal to the injured point in an end-to-side fashion using 10-0 nylon epineurial sutures. The effects were evaluated using analgesimeter recordings for the hind paw, electrophysiological tests, measurement of the muscle contraction force, a double-labeling technique, weight measurement and histological examination of the gastrocnemius muscle, histological examination of the bilateral sciatic nerves, and immunofluorescent staining. RESULTS: Results from the many tests used to evaluate the reverse end-to-side neurorrhaphy technique indicated that functional recovery of the denervated target organs was promoted by axonal augmentation. CONCLUSIONS: The reverse end-to-side neurorrhaphy technique could be useful in peripheral nerve repair.     

The use of silicone tubes in end-to-side nerve grafting: an experimental study

This study investigated the feasibility of inducing collateral nerve sprouting by artificial nerve grafts. The rat left peroneal nerve was severed and a 10-mm segment was removed. A perineurial window was created in the ipsilateral tibial nerve. The distal stump of the peroneal nerve was connected end-to-side to the perineurial window with either a nerve autograft (group A), a silicone tube (group B), or a silicone tube lined with cultured Schwann cells (group C). After 90 days light microscopy showed collateral nerve regeneration not only through the nerve grafts but also through silicone tubes. The presence of Schwann cells ensured significantly higher regeneration rate in the silicone tubes (87% in group C vs. 40% in group B) which was comparable to that of nerve grafts (100%). Interestingly, morphometric findings and functional recovery in the case of nerve regeneration were very similar in all groups.     

螺旋式改良神经端侧缝合法修复周围神经损伤的实验研究

目的 对治疗周围神经损伤的常规端侧缝合方法进行螺旋式改良端侧缝合实验研究,观察神经再生修复效果,为周围神经损伤的治疗提供效果更好的修复方法.方法 选用60只健康SD大鼠,采用右侧腓总神经修复模型.术中根据手术方法的不同,随机分为A、B、C三组,每组20只.每组将右侧腓总神经在其坐骨神经分出后3mm处局部封闭,利刀切断.A组神经远断端切成90°断面,行腓总神经端端缝合;B组神经远断端切成45°斜面,同时供体神经干外束膜开窗行端侧缝合;C组神经远断端切成10°斜面,供体神经干外束膜开窗,以螺旋式改良端侧缝合法进行神经束膜及外膜缝合.术后第8周分别对各组大鼠进行组织学、肌湿重、神经电生理检测,有髓神经纤维计数及神经示踪法观察.结果 螺旋式改良缝合组(C组)观察指标均优于常规端侧缝合组(B组)(P＜0.05),与端端缝合组(A组)比较差异无统计学意义(P＞0.05).螺旋式改良端侧缝合法对促进神经纤维的再生明显优于常规端侧缝合法.结论 神经断端采用螺旋式改良缝合后,神经再生良好;螺旋式改良缝合法较常规端侧缝合法能获得更有效的神经再生;长入远端的神经纤维多少与受端缝合接触面积大小有关.当临床遇动力神经缺乏时,采用神经螺旋式改良端侧缝合法可获得更好的修复效果.     

Helicoid end-to-side and oblique attachment technique in repair of the musculocutaneous nerve injury with the phrenic nerve as a donor: an experimental study in rats

The purpose of this study was to identify if a modified end-to-side repair can achieve equal results of nerve regeneration compared to an end-to-end repair using donor phrenic nerves in repair of the musculocutaneous nerve and also pulmonary protection. Eighteen rats were divided into three groups of six each comparing two nerve graft techniques: helicoid end-to-side plus distal oblique repair vs. traditional end-to-end repair, using a donor phrenic nerve. The saphenous nerve was used as a graft between the phrenic nerve and the musculocutaneous nerve. The third group was used as control; the musculocutaneous nerve was transected without any repair. Three months postoperatively, electrophysiology, tetanic force, moist muscle weight, histology, nerve fiber counting, and chest X-ray were evaluated. All results have shown that this modified end-to-side repair was superior to the end-to-end repair. The former did not compromise the diaphragm function, but the latter showed an elevation of the diaphragm. Little recovery was seen in the third group. The conclusion is that this modified end-to-side repair can replace the traditional end-to-end repair using donor phrenic nerves with better results of nerve regeneration without diaphragm compromise.     

Nerve repair by end-to-side coaptation or fascicular transfer: a clinical study

End-to-side nerve repair has recently achieved special interest in the laboratory. In clinical practice, its use remains controversial and very few studies have been published. In the present report, nerve repair by end-to-side neurorrhaphy and by fascicular transfer is evaluated in seven patients. Clinical, electrophysiologic and histologic recovery was not observed in the patients who underwent end-to-side nerve coaptation, but recovery was observed when a fascicular transfer was performed.     

Arthrotomography of the wrist: an experimental and preliminary clinical study

Experimental arthrotomography including posteroanterior and lateral projections was completed in 18 fresh-frozen wrists from cadavers with an average age of 65 years at death. Arthrotomographic findings were correlated with anatomic dissections. Three types of defects of the triangular fibrocartilage complex were clearly defined in 38% of wrists. Chondromalacia was present in 24% of wrists, in all cases on the ulnar half of the proximal surface of the lunate bone. The palmar radiocarpal ligaments (radiocapitate and radiotriquetral) were visible in all specimens. Experimental arthrotomography appears to be useful in defining the nature and location of soft tissue pathology in clinical practice. Clinical arthrotomography was performed in 16 patients, all with a syndrome of chronic wrist pain. Pathologic findings were observed in 11 wrists, including four perforations of the triangular fibrocartilage complex, two cases of chondromalacia of the lunate, one tear in each of the scapholunate and lunotriquetral ligaments, three occult palmar ganglia, and one recurrent dorsal ganglion. The soft tissues in five wrists were normal. The preliminary clinical experience with wrist arthrotomography has yielded results that have significantly affected the care of patients, including the planning of operative treatment and patient counseling.     

腕部桡尺神经浅支的解剖学研究

目的为在桡、尺骨远端骨折处经皮穿针固定提供一个安全进针区域,减少桡、尺神经浅支的损伤提供解剖学依据。方法成人前臂标本18侧,观察桡、尺神经浅支的走行规律。结果桡神经浅支从肱桡肌和桡侧腕长伸肌腱平均间穿出点与桡骨茎突纵向平均距离(L_1)为[(7．4±0．7)cm,(?)±s,下同]。其中16侧在穿出点与桡骨茎突纵向平均距离(L_2)为(4．5±0．6)cm处发出一级分支,称为尺侧支(Ⅰ)和桡侧支(Ⅱ)；尺侧支的桡侧分支(I a)与桡骨茎突的横向平均距离(L_3)为(1．0±0．3)cm,桡侧支与桡骨茎突横向平均距离(L_4)为(0．8±0．3)cm,纵向平均距离(L_5)为(1．5±0．4)cm。2侧桡神经浅支桡侧支被前臂外侧皮神经所替代。尺神经浅支手背支均从尺骨茎突的掌侧走行,与尺骨茎突距离为(0．9±0．3) cm。结论以桡骨茎突为中心,横向距离0．4cm．纵向距离0．6cm的椭圆形区域为桡神经分布相对盲区．从该区经皮克氏针固定桡骨远端,可有效地减少桡神经浅支损伤的发生率。尺骨远端骨折应从尺骨茎突背侧经皮进针相对较安全。     

Neuroma prevention by end-to-side neurorraphy: an experimental study in rats

PURPOSE: The successful treatment of painful neuromas remains a difficult goal to attain. In this report we explore the feasibility of neuroma prevention by insertion of the proximal end of a nerve through an end-to-side neurorraphy into an adjacent mixed nerve to provide a pathway and target for axons deprived of their end organ. METHODS: Experiments were performed on a total of twenty 250-g Sprague-Dawley rats. Two groups of 10 animals were prepared. Group A served as an anatomic control. In group B the right saphenous nerve was transected and implanted end-to-side through an epineurial window into the tibial nerve distal to the trifurcation of the sciatic nerve. After 12 weeks the corresponding sensory neurons were identified by retrograde labeling techniques and histomorphometric analysis of the proximal and distal tibial nerve segments, and regular histology of the end-to-side site were performed. RESULTS: The results of the retrograde labeling of the corresponding sensory neuron pool of the saphenus nerve showed extensive labelling of the L1 to L3 spinal ganglions after intracutaneous tracer application of the planta pedis. The morphology of the end-to-side coaptation site and histomorphologic analysis prove that sensory neurons penetrate the perineurial sheath and axons regenerate along the tibial Schwann cell tubes toward their targets. CONCLUSIONS: Axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented. Whether these axons will lead to disturbing sensations such as paresthesia or dysesthesia in the newly found environment or remain silent codwellers, this experiment cannot answer. Long-term results of future clinical work will have to decide whether the prevention of the neuroma through end-to-side coaptation will be an appropriate therapy for this difficult problem.     

Phrenic nerve end-to-side neurotization in treating brachial plexus avulsion: an experimental study in rats

The aim of this study was to extend the clinical application of phrenic nerve neurotization in treating brachial plexus avulsion injury, reducing the possible damage on the diaphragm function. Fifty-one male Sprague-Dawley rats and 9 transgenic rats were used in this study. Evaluations including behavioral observation, histology, and electrophysiology study were performed postoperatively. The functional recovery of rats with the end-to-side neurorrhaphy reached 80% of those with end-to-end neurorrhaphy, and the function of diaphragm was preserved. The fluorescence study revealed abundant collateral sprouting of the phrenic nerve axons through the coaptation site in all the experimental groups. The study showed that the end-to-side neurorrhaphy in a helicoid manner and the standard end-to-side neurorrhaphy were effective in the treatment of brachial plexus root avulsion injury with little harm to the function of diaphragm. This will extend the clinical application of phrenic nerve neurotization in treating brachial plexus avulsion injury.     

神经高位端端与低位端侧或侧侧缝合相结合提高神经修复能力的实验研究

目的对无缺损的周围神经高位损伤，提出高位端端与低位端侧或侧侧缝合相结合的新方法，观察神经再生和靶器官的恢复情况。方法SD大鼠80只，高位切断左侧胫神经。随机分为5组：A组：胫神经两断端行端端缝合，远端于膝关节水平与腓神经干行侧侧缝合。B组：断端处理同A组，远端移植正中神经作胫腓神经干之间的端侧桥接缝合。C组：单纯作断端的端端吻合。D组：胫神经干近端结扎并固定，远端与腓神经干行侧侧缝合。E组：近端处理同D组，远端切除部分神经段后，与腓神经干行端侧缝合。术后行肌电图检查及组织学观察并作统计学分析。结果术后早期（4周）D、E组有神经再生，术后12周A、B组的神经再生、传导功能及靶肌肉和运动终板的恢复情况均优于C、D、E组。结论高位端端与低位端侧或侧侧缝合相结合的方法，可尽早恢复对靶组织的营养和神经再支配，为高位缝合处高质量神经的长入赢得时间，提高了有效功能的恢复。     

Repair of the main nerve trunk of the upper limb with end-to-side neurorrhaphy: an experimental study in rabbits

The aim of this study was to assess the effectiveness of reinnervation using end-to-side neurorrhaphy in the upper extremity of the rabbit. The cut right ulnar nerve was repaired and sutured to the side of the median nerve about 3 cm above the elbow joint. The extent of reinnervation was quantitatively evaluated, as well as the integrity of the intact donor nerve in 36 rabbits randomly treated with fresh or delayed nerve repair with or without perineurotomy. Evaluations included nerve conduction velocity (NCV) of both the ulnar and medial nerves, dry muscle weight, and histologic examination (neurofilament stain and morphometric assessment) at 3 and 6 months postoperatively. NCV recovery rates were 79% and 87% for the ulnar nerve, and 89% and 94% for the median nerve compared to contralateral intact nerves, at 3 and 6 months, respectively. Flexor carpi ulnaris muscle mass measurements revealed a recovery in dry muscle weight of about 81% and 88% at 3 and 6 months, respectively, compared to the intact contralateral flexor carpi ulnaris. Histologic studies with neurofilament staining reveal numerous axonal sprouts at the distal end of the median nerve, indicative of myelinated axonal regeneration. Morphometric analysis demonstrated no difference between fresh and delayed repairs. These results indicate that in the upper extremity of rabbits, end-to-side neurorrhaphy permits axonal regeneration from the intact donor nerve, and is associated with satisfactory recovery. The effect of the procedure on the donor nerve was negligible.     

周围神经端侧缝合后神经再生及其趋化性的实验研究

目的进一步验证周围神经端侧缝合的有效性,初步探讨端侧缝合后神经再生的趋化性问题。方法雌性清洁级SD大鼠10只20侧,实验分3组,分别为神经端侧缝合组、正常对照组、切断对照组。神经缝合后5个月采用电生理、组织学、电镜等方法,观测再生神经纤维及其靶器官结构功能的改变;乙酰胆碱酯酶染色观测再生运动神经纤维及比例。结果端侧组肱二头肌复合肌肉动作电位的(CMAP)潜伏期较正常组减慢64％,最大波幅为正常组的27％。肱二头肌肌湿重为正常组的72％,肌纤维横截面积与正常组元明显差异。端侧组肌皮神经有髓神经纤维计数占正常组的44．5％,有髓神经纤维髓鞘厚度、最大直径、最小直径分别占正常组的85．9％、77．3％和65．5％。乙酰胆碱酯酶染色示端侧组肌皮神经主干运动神经纤维比例为[(0．39±0．07)％,x±s,下同],与正常组的差异无统计学意义;肱二头肌肌支运动神经纤维比例为(0．38±0．07)％,与正常组比较差异有统计学意义(P>0．01)。结论周围神经端侧缝合后有相当数目的再生神经纤维,但以髓鞘薄,直径小的纤维为主,同时能有效防止肌肉萎缩。周围神经端侧缝合后神经侧方出芽对特定靶器官的趋化性不明显。