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Precise nerve fascicle identification is important in certain peripheral nerve procedures. Although we believe bipolar nerve stimulation with intraoperative neuromonitoring is a superior method, many rely on clinical response evoked by handheld monopolar nerve stimulators. We present a modification in the use of the latter for a more precise fascicle stimulation. A 55-year-old man with a right high brachial plexus injury and a 47-year-old woman with a left median nerve schwannoma were scheduled for exploration and ulnar-to-musculocutaneous nerve transfer, and for surgical excision respectively. Intraoperatively, we used a disposable handheld monopolar nerve stimulator in an unorthodox way, placing the anode right next to the cathode (both touching the same nerve fascicle). In the first case, a fascicle that showed flexor carpi ulnaris (FCU) and intrinsic hand muscle contraction with standard stimulation (anode placed on patient's skin), showed only FCU activation with our modified method, and was chosen as donor. A BMC grade M4 elbow flexion was achieved 9 months after surgery. In the second case, safe schwannoma excision was performed after our modified stimulation technique caused thenar muscle activation in a single, unaffected fascicle, while standard monopolar stimulation showed activation in several fascicles. No unexpected motor/sensory deficits were noted during follow-up. This report shows an easy modification in the use of handheld nerve stimulators that improves selectiveness when looking for nerve fascicles., (© 2024 Wiley Periodicals LLC.)

Objectives: Double fascicular transfer is argued to result in improved elbow flexion compared to the traditional ulnar fascicular transfer because it reinnervates both the biceps and the brachialis. This study seeks to determine if double fascicular transfer should be preferred over ulnar fascicular transfer to restore elbow flexion in patients with upper trunk brachial plexus injuries (BPI) by analyzing the current database of literature on the topic., Methods: A systematic review was conducted according to PRISMA guidelines. Inclusion criteria were studies reporting Medical Research Council (MRC) scores on individual patients undergoing ulnar fascicular transfer and double fascicular transfer (ulnar and median nerve fascicle donors). Patients were excluded if: age < 18 years old and follow-up <12 months. Demographics obtained include age, sex, extent of injury (C5-C6/C5-C7), preoperative interval, procedure type, and follow-up time. Outcomes included absolute MRC score and ability to achieve MRC score ≥3 and ≥4. Univariate and multivariate regression analyses were completed to evaluate predictors of postoperative outcomes., Results: Eighteen studies (176 patients) were included for pooled analysis. Patients that underwent double fascicular transfer had a higher percentage of patients attain a MRC score ≥ 4 compared to ulnar fascicular transfer subjects (83.0% vs. 63.3%, p = .013). Double fascicular transfer was a predictor of achieving high MRC scores (OR = 2.829, p = .015). Multivariate analysis showed that procedure type was the only near significant predictor of ability to obtain MRC ≥4 (OR: 2.338, p = .054)., Conclusions: This analysis demonstrates that double fascicular transfer is associated with superior postoperative outcomes and should be performed for restoring elbow flexion., (© 2019 Wiley Periodicals, Inc.)

Background: Arthrogryposis multiplex congenita (AMC) is a rare disease which affects mainly upper and lower extremities. Affected patients are not able to eat unassisted due to elbow contracture and nonexistent active elbow flexion. In traumatic brachial plexus palsies, a nerve transfer from either median or ulnar nerve to the musculocutaneous nerve has proved to induce active elbow flexion, and we report our results of such a procedure in a nontraumatic condition, that is, arthrogryposis., Methods: We selected four patients with AMC type 1 (6 extremities, 2 males, 2 females) diagnosed with AMC presenting to our institution shortly after birth from 2014 to 2016 to perform a nerve transfer from the median nerve to the musculocutaneous nerve in order to induce active elbow flexion. The indication of application of this surgical procedure was based on active finger and wrist flexion, limited contracture of elbow joints and evidence of flexing muscle fibers detected by sonography., Results: Five nerve transfers were conducted with a follow up of 2-5 years. Two extremities reached active elbow flexion motorgrade M4, two M3, and one M1 at latest follow up. One patient developed a postoperative suture granuloma. One nerve transfer was abandoned due to neuroanatomic variation. One extremity was treated with botulinum toxin in triceps muscle in addition to the nerve transfer., Conclusions: In this series of selected cases of AMC Type 1 we were able to induce active elbow flexion using a nerve transfer technique developed for traumatic and obstetric brachial plexus palsies. In four extremities the procedure achieved independent hand-to-mouth active elbow flexion. Level of evidence four., (© 2019 Wiley Periodicals, Inc.)

Background: Due to limited number of studies, we tested feasibility of autologous epineural sheath conduit (ESC) in repair of 6-cm median nerve gaps in a sheep-the large animal model., Materials and Methods: Eight ewes, 6-8 months old, 30-35 kg, were divided into three experimental groups: group 1-no defect repair (n = 4 nerves/group), group 2-autograft controls (n = 6 nerves/group), group 3-autologous ESC filled with saline (n = 6 nerves/group). ESC was constructed from a 6-cm long segment of sheep median nerve and tested for expression of laminin B, Glial fibrillary acidic protein (GFAP), S-100 and CD31 using immunofluorescent staining. At 6 months after nerve repair, nerve conduction velocity and somatosensory evoked potentials (SSEP) assessed neurosensory recovery, while histomorphometry tested nerve regeneration., Results: Ex vivo characterization of ESC, before in vivo nerve gap repair, showed high laminin B expression, which supports axonal growth. At 6 months post-repair, structural integrity of ESC was preserved. ESC was well-vascularized and tissue adhesions were comparable to autograft controls. The maximal conduction velocities (29.80 ± 5.85 ms vs. 32.28 ± 6.75 ms; p = .44), action potential amplitudes (32.68 ± 17.44 mV vs. 44.14 ± 23.10 mV; p = .38) and SSEP amplitude values (6.18 ± 5.84 mV vs. 4.68 ± 2.53 mV; p = .28) were comparable between autograft and ESC groups. Presence of regenerating axons was confirmed in the distal segment of ESC at 6 months after repair., Conclusion: The feasibility of ESC in restoration of 6-cm long nerve defects in a sheep median nerve model was confirmed by nerve conduction assessments and correlated with axonal regeneration tested by histomorphometry. We confirmed ESC potential in support of regeneration of long nerve defects., (© 2018 Wiley Periodicals, Inc.)

Objectives: Absence of sensation in C8-T1 dermatome is a common finding in midcervical spinal cord injury. The goal was to restore sensation on the C8-T1 dermatomes by transferring sensory nerves with afferents on C5-C6 roots., Methods: A mean 10 months post spinal cord injury, we operated on 10 upper limbs from 5 tetraplegics averaging 23 years old. Cutaneous branches of the median nerve were transferred to the palm to the ulnar proper digital nerve of the little finger. In two patients, the lateral antebrachial cutaneous nerve was also transferred to the medial antebrachial cutaneous nerve., Results: At a mean 20 months after surgery, on the ulnar side of the hand and little finger, all patients were able to perceive 19.3 g Semmes-Weinstein monofilament pressure. Nociception was restored on the medial side of the elbow, forearm, and hand. Faulty location was a common finding, but not as a major complaint., Conclusions: Sensory nerve transfers should be incorporated into the reconstruction of the upper limb in tetraplegics. © 2015 Wiley Periodicals, Inc. Microsurgery 36:637-641, 2016., (© 2016 Wiley Periodicals, Inc.)

Skin graft coverage of critical marginal wounds in microsurgical cases is the earliest described method for coverage of exposed vessels, nerves, and other vital structures at the margins of replanted or transplanted tissue. A case of immediate graft coverage of vein and nerve graft repairs in a gunshot wound is presented with a 5-year follow-up demonstrating stable coverage, salvage of the microsurgical reconstruction, and no contracture. Compared to recently described strategies of interval biosynthetic dressings and delayed skin grafting, immediate skin grafts application remains the most effective management of these wounds., (Copyright © 2013 Wiley Periodicals, Inc.)

Despite extensive research and surgical innovation, the treatment of peripheral nerve injuries remains a complex issue, particularly in nonsharp lesions. The aim of this study was to assess the clinical outcome in a group of 16 patients who underwent, in emergency, a primary repair for crush injury of sensory and mixed nerves of the upper limb with biological tubulization, namely, the muscle-vein-combined graft. The segments involved were sensory digital nerves in eight cases and mixed nerves in another eight cases (four median nerves and four ulnar nerves). The length of nerve defect ranged from 0.5 to 4 cm (mean 1.9 cm). Fifteen of 16 patients showed some degree of functional recovery. Six patients showed diminished light touch (3.61), six had protective sensation (4.31), and three showed loss of protective sensation (4.56) using Semmes-Weinstein monofilament test. All the patients who underwent digital nerve repair had favorable results graded as S4 in one case, S3+ in six cases, and S3 in one case. With respect to mixed nerve repair, we observed two S4, two S3+, two S3, one S2, and one S0 sensory recovery. Less favorable results were observed for motor function with three M4, one M3, two M2, and two M0 recoveries. Altogether, the results of this retrospective study demonstrates that tubulization nerve repair in emergency, in case of short nerve gaps, may restore the continuity of the nerve avoiding secondary nerve grafting. This technique preserves donor nerve and, in case of failure, does not preclude a delayed repair with a nerve graft., (Copyright © 2012 Wiley Periodicals, Inc.)

We evaluated the feasibility of external epineurial splinting as a way of alleviating tension caused by sutures in the reconstruction of peripheral nerve injuries, utilizing Wistar rat median nerve injury on 40 animals, in four experimental groups with 10 animals on each surgical setting. The nerve regeneration outcomes of four surgical procedures were compared: 1) primary end-to-end sutures (EES); 2) alleviated tension sutures (ATS) with a removal of 7 mm nerve segment, namely external epineurial splinting, utilizing a polypropylene mesh as a protective scaffold; 3) sutures under tension with a 7 mm gap between nerve stumps; and 4) sham (C) (n = 10 animals). Regeneration of the median nerve postneurorrhaphy was followed by means of functional evaluations, including time to first day of finger flexion recovery, and grasp strength; quantification of atrophy of the flexor pronator muscle group; and mRNA expression of nerve growth factor and neurotrophin-3 by polymerase chain reaction-reverse transcriptase. Similar, significant median nerve regeneration was observed in the EES-treated and ATS-treated groups, relative to controls. The EES and ATS surgical procedures methods demonstrated important similar results considering functional and molecular biology analysis of the median nerve injury., (Copyright © 2011 Wiley-Liss, Inc.)

Eleven patients over 40 years old, with median nerve lesions at the wrist, were operated on an average of 5 months after their injury. In six patients, the median nerve was repaired using a polypropylene mesh applied to secure the nerve stumps in contact, thereby allowing for direct repair with microsutures. Six patients had their median nerve repaired with sural grafts. The average gap length was 2.8 cm for the mesh repair, whereas it was 3.7 cm for the graft repair group. Eighteen months after surgery, pressure thresholds were perceived in the index and thumb pulp by all six patients with a mesh repair but in only two of five patients with a graft repair. Five in the mesh repair group recovered function in the abductor pollicis brevis muscle, versus none in the graft group. These preliminary results suggest that, in older patients, the use of a mesh to splint the coaptation site followed by direct nerve repair yields better recovery than conventional sural grafts., (Copyright © 2011 Wiley-Liss, Inc.)

Objective: In this report, we present the findings of reinnervation of the thenar muscle in five patients who underwent the contralateral C7 nerve root transfers for repair of total brachial plexus root avulsions., Patients and Methods: Five (2 children and 3 adults) of 32 patients who received two-staged procedures of the contralateral C7 nerve root transfers to the median nerves showed reinnervation of thenar muscle were evaluated. The patients also received other procedures including the intercostal nerve transfer to the musculocutaneous nerve, the spinal accessory nerve to the suprascapular nerve, and the ipsilateral phrenic nerve to the musculocutaneous nerve before the contralateral C7 nerve root transfers. The patients were followed up from 24 to 118 months after surgery., Results: Varied degrees of functional restorations were achieved after different procedures. The strength of abductor pollicis brevis (APB) muscle with Grade M2 was found in four patients. The incomplete interference pattern in the APB muscle was detected by electromyogram (EMG) in two patients, and the minority motor unit potential (MUP) was detected in other two patients. The strength of APB muscle was found with Grade M1 in one patient with EMG showing MUP., Conclusion: The findings from our series show reinnervation of thenar muscles after repair of the median nerve with the contralateral C7 nerve root transfer, which provides evidence for further investigation of reconstruction of the brachial plexus root avulsion injury with this procedure., (Copyright © 2010 Wiley-Liss, Inc.)

A comparison of outcomes based on a scoring system for assessments, described by Rosén and Lundborg, after sharp complete laceration of median and/or ulnar nerves at various levels in the forearm was carried out. There were 66 males (90.4%) and 7 females (9.6%), with a mean age of 31 years (range: 14-62 years). The patients were categorized into three groups according to the type of nerve injury. The median nerve was injured in 25 cases (group M, 34.3%), the ulnar in 27 (group U, 36.9%), and both the nerves in 21 (group MU, 28.8%). The demographic data of the patients and the mechanism of injury were recorded. We also examined the employment status at the time of the injury and we estimated the percentage of patients who returned to their work after trauma. In all cases, a primary epineural repair was performed. Concomitant injuries were repaired in the same setting. The mean period of time between injury and surgery was 5.3 hours (range: 2-120 hours). A rehabilitation protocol and a reeducation program were followed in all cases. The mean follow-up was 3 years (range: 2-6 years), with more distal injuries having a shorter follow-up period. The total score was 2.71 in group M (range: 0.79-2.99) and 2.63 in group U (range: 0.63-3), with no significant differences observed. There was a significant difference between these two groups and group MU (total score 2.03, range: 0.49-2.76, P = 0.02). Up to the last follow-up, 61 patients (83.5%) had returned to their previous work. The Rosén-Lundborg model can be a useful and simple tool for the evaluation of the functional outcome after nerve injury and repair temporally reflecting the processes of regeneration and reinnervation., (Copyright © 2010 Wiley-Liss, Inc.)

The purpose of our study was to establish the profile of cortical reorganization in whole BPAI on rats and evaluate changes of cortical reorganization after repair of the median nerve with the contralateral C7 root transfer. Forty adult SD rats underwent whole roots avulsion of left brachial plexus, among them 20 received contralateral C7 root transfer to the injured median nerve. Intracortical microstimulation was performed in primary motor cortex (M1) at intervals of 3, 5, 7, and 10 months, postoperatively. The maps of motor cortical responses were constructed. Five normal rats were used as the control. Results showed that stimulating right M1 elicited motion of left vibrissae, submaxilla, neck, back, and left hindlimb after left BPAI, among them neck representation area replaced the forelimb area throughout the reorganization process. The left forelimb representation area was found in the left motor cortex 5 months after the contralateral C7 root transfer and existed in both motor cortexes at 7th postoperative month. The left forelimb representation area was detected only in right motor cortex at 10th month, postoperatively. In conclusions, after the contralateral C7 root transfer for repair of the median nerve in BPAI, the cortical reorganization occurred in a time-dependent reorganization. The findings from this study demonstrate that brain involves in the functional recovery after BPAI and repair with nerve transfer and suggest that efforts to improve the results from nerve repair should address the peripheral nerve as well as the brain., (2010 Wiley-Liss, Inc. Microsurgery 2010.)

In repair of the high voltage electrical injuries of peripheral nerve, selection of the proper plane for nerve coaptation after debridement is important since the electrical current is inclined to pass through the nerve trunks due to the lower electric resistance. In this report, we present our experience on use of the somatosensory evoked potentials (SSEP) test to assist determination of range of the injured nerve debridement in the electrical injured nerve. From January 1997 to December 2007, 30 patients with the high voltage electrical injury in the wrist, having defect of median nerve, were treated with nerve grafting. In 18 patients, the nerve resection plane was selected with the assistance of SSEP. In 12 patients, the nerve resection plane was determined by the traditional gross examination. The average lengths of nerve defect after debridement were 10.4 cm in the procedure with SSEP assistance and 4.01 cm in the traditional procedure. The finger motion was reconstructed by the tendon graft connecting the proximal forearm muscle and the distal tendon of flexor disitorum profundus. In following up, the two-point discrimination of finger was examined. The grade of finger sensory recovery was found improved in the patients who underwent the nerve repair with SSEP assistance than that in the patients underwent treatment with the traditional method. The results suggested that aggressive debridement is recommended for the high with voltage electrical nerve injury. SSEP could be a valuable tool for determination of the range of nerve debridement., (Copyright 2009 Wiley-Liss, Inc. Microsurgery 2009.)

Purpose: End-to-side (ETS) nerve repair allows for target-muscle reinnervation, with simultaneous preservation of donor-nerve function. Acetyl-L-carnitine (ALCAR) was shown to enhance axonal sprouting in early regeneration following transection and repair of the sciatic nerve in rodents. The purpose of this article was to determine the ability of ALCAR to enhance axonal regeneration in an ETS rodent model., Method: The right musculocutaneous nerve in 16 adult male Sprague-Dawley rats was transected to induce biceps muscle paralysis. The distal stump was then coapted by ETS neurorrhaphy through a perineurial window to the ipsilateral median nerve. Experimental groups received ALCAR for 1, 2, 3, and 4 weeks whereas controls received placebo., Results: Weekly postoperative behavioral evaluations revealed increased functional return over control but the difference was not significant. Potentials from biceps were recorded from the third postoperative week in the experimental group and from the fourth week in the control group. Histomorphometric evaluations revealed higher musculocutaneous nerve axon counts, higher myelin thickness in the fourth postoperative week, and differences in the appearance and the number of motor-end-plates in the biceps in experimental versus control group., Conclusion: Intraperitoneal administration of ALCAR can expedite biceps muscle recovery in an ETS model by increasing the rate of axonal regeneration. Despite the morphological changes, no behavioral changes were noted and further studies are needed to confirm clinical efficacy of ALCAR for potential use in the development of therapeutic protocols., (Copyright 2009 Wiley-Liss, Inc. Microsurgery 2009.)

Skeletal muscle atrophy represents one of the main causes of poor outcome of microsurgical nerve reconstruction. Recent studies have pointed to the importance of the neuregulin/ErbB signaling pathway in the development and regeneration of the neuromuscular system. Here, we show by immunohistochemistry, RT-PCR, and Western blotting analyses, in an in vivo model of adult skeletal muscle denervation/reinnervation, that expression of Neuregulin1 (NRG1) and ErbB receptors is regulated by the innervation condition. We found out that a significant upregulation of the alpha-, but not beta-, isoform of NRG1, as well as of ErbB2, ErbB3, and ErbB4-cyt1 isoform occurs as a consequence of denervation of flexor digitorum muscles of the rat forelimb by median nerve transection. Moreover, after tubulization median nerve repair, and consequent muscle reinnervation, all messengers of the NRG1/ErbB system are promptly downregulated. Therefore, our results suggest the existence of a alpha-NRG1-mediated autocrine and/or paracrine trophic loop in skeletal muscles that is activated after denervation and promptly deactivated after nerve reconstruction. This myotrophic loop is a promising therapeutic target for the prevention of muscle atrophy. Yet, the recent demonstration of a similar alpha-NRG1-mediated gliotrophic loop in denervated Schwann cells provides a possible explanation for the effectiveness of muscle conduits for tubulization nerve repair., (Copyright 2009 Wiley-Liss, Inc. Microsurgery 2009.)

Brachial plexus trauma is a rare condition in children except for obstetrical lesions, for which nerve grafting is generally proposed. Two children (9 and 12 years old) with C5 and C6 traumatic brachial plexus avulsion lesions are presented, where elbow flexion and shoulder abduction and external rotation were the functions to be restored. Nerve transfers have been performed. Shoulder abduction was restored by an accessory-to-suprascapular nerve transfer in one patient, while the triceps long head motor branch was transferred to the axillary nerve in both patients. Fascicles of the ulnar and median nerve were transferred respectively to the biceps muscle nerve and the brachialis motor branch. At 11 months follow-up, the elbow flexion scored M4 and the shoulder abduction recovered in both patients. No complications were observed. Nerve transfers currently used in adult patients may be applied in children with traumatic partial brachial plexus palsies., (Copyright 2008 Wiley-Liss, Inc. Microsurgery, 2008.)

We have developed a chitosan/polyglycolic acid (PGA) artificial nerve graft which was previously used for bridge implantation of dog sciatic nerves across 30-mm long defects. Here we describe a clinical trial of this graft for repairing a 35-mm-long median nerve defect at elbow of a human patient. During the 3-year follow-up period, functional recovery of the injured median nerve was assessed by pinch gauge test, hydraulic hand dynamometry, static two-point discrimination and touch test with monofilaments, in couple with electrophysiological examinations. The motor and sensory function of the median nerve demonstrated an ongoing recovery postimplantation, reaching M4 and S3+ levels during the follow-up period. The results indicate that the chitosan/PGA artificial nerve graft could be used for surgical repair of larger defects in major peripheral nerves at a higher level in the human., ((c) 2008 Wiley-Liss, Inc. Microsurgery, 2008)

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., ((c) 2007 Wiley-Liss, Inc.)

Over the last 10 years, we have investigated a particular type of bioengineered nerve guide, the muscle-vein-combined tube, which is made by filling a vein with skeletal muscle. In our previous studies we have always used fresh skeletal muscle to fill vein conduits. In the present study we compared the use of fresh and predegenerated (freeze-thawed) skeletal muscle for muscle-vein-combined nerve guides. In this study, a 10-mm-long rat median nerve defect was repaired using either type of nerve guide. The samples were analyzed 5 and 30 days after surgery by light and electron microscopy. In addition, reverse transcription polymerase chain reaction (RT-PCR) was carried out to investigate the expression of mRNAs coding for glial markers, as well as glial growth factor (NRG1) and its receptors (erbB2 and erbB3). Results showed differences between the two types of nerve guides at postoperative day 5; however, no difference was detected at day 30 suggesting that both types of tissue-engineered conduit are effective for repairing peripheral nerve defects in this experimental model., ((c) 2007 Wiley-Liss, Inc.)

A retrospective review of 42 patients with spaghetti wrist lacerations operated on by the author between June 1997 and May 2005 was completed. A total of 31 males and 11 females, average age of 17.1 years (range, 2-40 years), sustained spaghetti wrist injuries. The most frequent mechanisms of injury were accidental glass lacerations (55%), knife wounds (24%), and electrical saw injuries (11%). An average of 9.16 structures was injured, including 6.95 tendons, 1.4 nerves, and 0.8 arteries. The most frequently injured structures were median nerve (83%), flexor digitorum superficialis 2-4 tendons (81%), flexor digitorum profundus 2-4 tendons (66%), ulnar nerve and ulnar artery (57%), and flexor pollicis longus (40%). Combined flexor carpi ulnaris, ulnar nerve, and ulnar artery (ulnar triad) injuries occurred in 31%, while combined median nerve, palmaris longus, and flexor carpi radialis injuries (radial triad) occurred in 43%. Simultaneous injuries of both median and ulnar nerves occurred in 40.5%. Simultaneous injuries of both ulnar and radial arteries occurred in 14%. Neither artery was injured in 30.9%. Follow-up has ranged from 1 to 8 years, with an average of 46 months. Only four patients have been completely lost to follow-up. Range of motion of all involved digits (tendon function) was excellent in 34 patients, good in 3 patients, and poor in only 1 patient. Opposition was excellent in 31 patients, good in 5 patients, and poor in 2 patients. Intrinsic muscle recovery was subjectively reported to be excellent in 29 patients, good in 7, and fair to poor in 2 patients. Minor deformity (partial clawing) was reported in 4 patients and 1 patient has major deformity (total clawing). Sensory recovery was reported, excellent in 32 patients, good in 5 patients, and fair in only 1 patient., ((c) 2007 Wiley-Liss, Inc.)

End-to-side and side-to-side techniques (what we call alternative nerve repair techniques) have been investigated in detail in both experimental and clinical studies. There have not been any large series, but only some case reports describing either successful or disappointing functional results in the recent literature. Two cases presented here were of two extreme examples of nerve injuries that had no chance for direct repair; alternative choices were performed. One was a side-to-side neurorrhaphy between the ulnar and median nerves, and the other was an end-to-side nerve repair of the median and radial nerves to the ulnar nerve. Both patients regained their diminished protective sensation and returned to their occupations. Based on these results and our review of the current literature, we consider alternative nerve repair techniques to be reasonable, prudent, and scientific choices for the treatment of some challenging nerve injury cases.

Y-shaped vein conduits enriched with fresh skeletal muscle fibers were used to bridge a concomitant ulnar and median nerve transection with substance loss in rats. The proximal limb of the Y-chamber was sutured to the proximal ulnar nerve, while the two distal limbs were sutured to ulnar and median distal nerve stumps. Eight months after surgery, median nerve functional recovery was evaluated by means of the grasping test, and nerve fiber regeneration in both repaired nerves was assessed by means of design-based histomorphometry. Results showed that nerve fibers regenerated along both severed nerve trunks, and in the median nerve led to a recovery corresponding to 58% of normal nerve function. Quantitative analysis showed no significant morphological differences between myelinated nerve fibers regenerated along the two distal nerves except for the number of fibers, which was higher in the median nerve. Notably, the total number of regenerated nerve fibers in the two distal nerves was 4-fold the normal fiber number in the ulnar nerve. Besides their interest in relation to the long-lasting debate about the topographic specificity of nerve regeneration, the results of this study show an effective way to repair, in the rat experimental model, two transected nerve trunks innervating agonistic muscles in the case that the proximal stump of only one nerve is preserved., ((c) 2004 Wiley-Liss, Inc.)

Many techniques have been developed for the evaluation of peripheral nerve function. Consequently, physicians use different techniques in the clinic. This study describes the evaluation of touch after median nerve lesions in the forearm and repair. In order to evaluate touch, 25 patients, aged 11-51 years (mean, 29 years), were evaluated 3-10.5 years (mean, 5 years) after median nerve repair. The evaluation included the moving two-point discrimination test and Semmes-Weinstein monofilaments. We showed that 32% good-excellent results can be obtained with difficult nerve lesions. The results could have been improved if a sensory reeducation regime had been applied., (Copyright 2003 Wiley-Liss, Inc.)

In total, 41 consecutive patients with "idiopathic carpal tunnel syndrome" and abnormal electrophysiologic findings who underwent carpal tunnel release were studied prospectively. The focus of this investigation was the evaluation of the levels of specific chemical mediators within the serum and flexor tenosynovium of these patients. Blood was collected from these patients within 1 week prior to carpal tunnel release, and flexor tenosynovium was obtained at time of surgery. Specimens were then analyzed to determine the levels of interleukins 1 and 6, prostaglandin E(2) (PGE(2)), and malondialdehyde bis diethyl acetal. These values were compared to those of controls who had no evidence of carpal tunnel syndrome. A significant increase was noted in the serum malondialdehyde and tenosynovial levels of malondialdehyde, interleukin 6, and prostaglandin PGE(2) compared to controls. The elevated levels of these biologic factors and the absence of interleukin 1 elevation support a noninflammatory ischemia-reperfusion etiology for so-called "idiopathic carpal tunnel syndrome" that causes progressive edema and fibrosis of the tissues within the carpal canal. These findings correlate with previous histopathology reports. We believe that "idiopathic carpal tunnel syndrome" is an "-osis" not an "-itis.", (Copyright 2002 Wiley-Liss, Inc. MICROSURGERY 22:378-385 2002)

Carpal tunnel syndrome is encountered frequently in the every day practice for many orthopaedic surgeons and neurosurgeons. However, the rate of recurrence or incomplete relief is high and difficult to treat. This may be related to the high percent of anomalies of the median nerve and its surrounding tissues. A case of a split median nerve entrapped by an abnormally inserted palmaris longus muscle is presented. The case is discussed and a conclusion of safer standard surgical release is recommended, especially in doubtful cases., (Copyright 1999 Wiley-Liss, Inc.)

In the Istanbul Hand Surgery and Microsurgery Centre, between 1991-1996, 28 out of 54 patients who had clean-cut median nerve laceration at the wrist level were evaluated in a detailed manner regarding the improvement of sensibility following primary repair. Semmes-Weinstein monofilament and vibration tests form the group of threshold tests, and static and dynamic two-point discrimination tests and the Moberg pick-up test form the group of functional tests which were applied to the patients. Follow-up was from 1 to 5 years. Moreover, subjective findings such as cold intolerance, pain, and paraesthesia were also evaluated. All the results obtained were evaluated in relation to the SO-S4 sensibility improvement criterion which Waylett-Rendall recommended. The following results were obtained: S4 in 35.7% of the patients, S3+ in 28.5%, S3 in 14.2%, S2+ in 7.14%, S2 in 10.7%, and S1 in 3.5%. In our opinion the most important reason for the high rate of success was the fact that we worked with a highly selective group of patients and the fact that there was a high rate of young patients in this group (21.4% of them were under the age of 15). It was observed that there was a significant correlation between age and functional sensibility improvement (P = 0.04). Moreover, when we observed the relation between age and Semmes-Weinstein monofilament, static two-point discrimination, and dynamic two-point discrimination tests, it was seen that age had a significant correlation with each of the parameters (r = 0.61, P = 0.001; r = 0.58, P = 0.002; r = 0.57, P = 0.002). There was a clear decline in the intensity of the paraesthesia in S3+ and S4 group (X2 = 4.7, P = 0.02) and in these groups the period of Moberg pick-up test was meaningfully short (P < 0.05).

This clinical pilot study evolved from a 10-year experience in the experimental laboratory using continuous muscle stimulation in a series of animal studies following nerve injury and microsurgical repair. A completely implantable system was developed (Medtronic) to provide electrical stimulation to the denervated muscles until nerve regeneration had occurred. Both peripheral nerve injuries in the extremities and facial nerve severances were studied, and a definite improvement in functional capacity was obtained as well as improved morphology compared with nonstimulated controls. In this study, 13 patients with peripheral nerve injuries in the upper extremity are included. All patients had muscle stimulation for extended periods until nerve regeneration was evident; a careful analysis of their functional capacity was then completed. There were five patients with median nerve injuries, four with ulnar nerve or combined median-ulnar nerve injuries, and four with severed radial nerves. All patients showed satisfactory nerve regeneration on clinical examination and electromyographic studies. Motor recovery was usually better than sensory return. Functional muscle analysis varied somewhat from patient to patient, but every patient had a satisfactory to excellent recovery. Patients with low nerve lesions had better results, but muscle recovery even in patients with mid-forearm or higher nerve injuries was most encouraging. Functional recovery in radial nerve injuries was close to normal in all cases. The results from this pilot study have clearly shown the benefits of continuous muscle stimulation using an implantable system following nerve injury and repair.

Clinical failure of vein conduits for repair of four nerves in three cases is reported. Two digital nerves with gaps of 5.0 cm and 5.8 cm, respectively, and two median nerves with gaps of 4.0 cm and 5.0 cm were repaired with vein conduits. The digital nerves were repaired secondarily with insertion of nerve tissue slices. The median nerve lacerations were associated with compound soft tissue injuries and were repaired primarily by interfascicular vein conduits. There was no detectable recovery of sensibility in autonomous areas of these nerves and no sign of recovery of the innervated muscles during follow-up. Re-exploration revealed that the vein conduits used for repair of the median nerves were constricted by surrounding scar tissue and axon regeneration was precluded. The critical length for nerve regeneration in human beings and wound conditions unfavorable to nerve regeneration are discussed. This report suggests that vein conduits are not indicated in nerve gaps over 5.0 cm or in primary repair of nerves with compound injuries.

Ten patients with a root avulsion type of brachial plexus injury were treated with simultaneous intercostal nerve crossing to the musculocutaneous and median nerves, and nine cases were followed for more than 40 months. The average interval from injury to surgery was 2.7 months. The average age at operation was 18.6 years. The elbow flexor was M4 in six patients, M3 in two patients, and M1 in one patient. The wrist flexor was more than M3 in six patients and less than M2 in four patients. The finger flexor was more than M3 in four patients and less than M2 in five patients. Protective sensation in the areas innervated by the musculocutaneous and median nerves was restored in all cases.

Between 1986 and 1993, 643 patients with peripheral nerve trauma were treated in our clinic. Primary neurorraphy was performed in 431 of these patients and nerve grafting in 212 patients. We present the functional results after nerve grafting in 93 patients with large nerve defects who were followed for more than 2 years. Evaluation of function was based on the Medical Research Council (MRC) classification for motor and sensory recovery. Factors affecting functional outcome, such as age of the patient, denervation time, length of the defect, and level of the injury were noted. Good results according to the MRC classification were obtained in the majority of cases, although function remained less than that of the uninjured side.

The use of microsurgical techniques is essential in peripheral nerve surgery, in which dissection at the fascicular level is required. Magnification with an operating microscope allows for an accurate evaluation of the severity of the trauma to the nerve tissue and permits atraumatic interfascicular dissection. Fascicular or interfascicular dissection and repair with the use of nerve grafts was carried out in 220 peripheral nerve lesions of the upper extremity. Our results of nerve-grafting in the upper extremity (median, ulnar, and radial-nerves) indicate an inverse association between the age of the patient and the delay between injury and grafting. In addition, we found that nerve grafting without tension produces superior results over simple neurorrhaphy under tension and permits better axonal growth and nerve recovery.

Penetrating glass injuries are a common cause of severe neurovascular damage, both in adults and in children. Frequently, an innocent skin wound disguises the extensive nature of the injuries beneath. Nineteen children and adolescents (ages 3-16 years) with a mean age of 9 years who sustained upper extremity penetrating glass wounds were evaluated retrospectively in order (1) to determine the incidence of unappreciated significant neurologic, musculotendonous, or vascular injury; (2) to provide indications for intraoperative evaluation under anesthesia; and (3) to further define the role of microneurorrhaphy in this population. Twelve patients sustained injuries above the elbow and seven patients injuries distal to the elbow. Above the elbow, the structures injured in order of frequency were the median nerve (75%), the brachial artery (58%), the ulnar nerve (50%), the musculocutaneous nerve (33%), sensory nerves of the arm and forearm and venae commitantes (42% each), the radial nerve (25%), and the chords of the brachial plexus (8%). Distal to the elbow, the ulnar nerve was the most frequently involved (71%), followed by the ulnar artery (57%), the flexor carpi ulnaris (57%), the superficialis and profundus flexor tendons (43%), the median nerve (43%), and the palmaris longus and flexor carpi radialis (14% each). Early exploration is critical to successful management. Vascular repairs and or microneurorrhaphy were necessary in all cases. A detailed follow-up evaluation to assess the results of these repairs was carried out from 4 to 9 years postsurgery. There were no clinical problems related to the vascular reconstructions. The results of the nerve repairs in this small series of children and adolescents were remarkably good.(ABSTRACT TRUNCATED AT 250 WORDS)

Since 1979 acetylcholinesterase has been used in clinical practice for motor sensory differentiation. It was first used for median and ulnar nerve injuries at the wrist. Recently the application was extended to secondary nerve repair, including plexus reconstruction. The aim of this study was to present, for the first time, clinical results of motor sensory differentiated median and ulnar nerve repair and to show the advantage of this method in secondary repair. We compared a group of nine patients with motor sensory differentiated median and ulnar nerve repair with a group of 13 patients without motor sensory differentiation. Sensibility testing, strength measurements, and anatomical examinations were performed. The hand function was expressed in percentage values. Compound muscle action potentials and sensory antidromic conduction velocities were measured electroneurographically. Sensibility recovery was significantly better after motor sensory differentiated median nerve repair (P < 0.05). In secondary nerve repair acetylcholinesterase was used additionally for evaluating the level of resection of the proximal stump. The time required for perioperative histochemical differentiation has now been reduced to 2 hr.

A large neurofasciocutaneous flap that consisted of a peroneal flap and a segment of sural nerve was used in the simultaneous reconstruction of a large soft tissue and nerve defect caused by a crushing injury of the distal forearm. A 10 x 15 cm peroneal flap, including a 10 cm segment of sural nerve, was successfully transferred to an 8 x 12 cm skin defect, reconstructing a 5 cm defect of the median nerve. Two years after repair, the opponens pollicis muscle showed good contraction, although palmar abduction of the thumb remained poor. Static two-point discrimination was 20 mm on the pulp surface of both thumb and index finger and 15 mm on the middle finger.

The sural nerve was described as a new donor nerve of the free vascularized nerve graft in a fresh cadaver's dissection and in four clinical cases. The vascularized sural nerve is nourished by the cutaneous branch of the peroneal artery or the muscular perforating branch of the posterior tibial artery in our grafts. Compared to other vascularized nerve grafts, the sural nerve has many advantages: 1) A "two- or three-fold nerve graft" can be designed on itself without damage to the blood supply of the nerve, 2) survival of the nerve can be reasoned by the accompanying flap and the flap can close the skin defect simultaneously without additional vascular anastomosis, and 3) sensory loss at the donor site is negligible. The final extent of sensory recovery in our clinical cases could require several months, but a quickly advanced Tinel's sign suggested the technique's superiority.

An overview of the concepts on peripheral nerve regeneration and of research on the progress in this field is carried out. Problems of regeneration and factors influencing it, both improving and worsening it, are considered, especially with respect to the clinical treatment of nerve lesions. Classical techniques of repair (sutures and grafts) as well as very new methods (e.g., direct muscular neurotization) are discussed. Postoperative treatment and result evaluation are presented.

A histological and functional comparison of regeneration across a vascularized and conventional nerve graft was carried out in a clinical case. The two branches of the medial antebrachial cutaneous nerve were used to neurotize the median nerve at the wrist. The superficial branch of the radial nerve (vascularized nerve graft) and a conventional sural nerve graft were used as the interposition grafts between the two branches of the medial antebrachial cutaneous nerve and the median nerve. This nerve grafting procedure was carried out in two stages. The proximal neurorrhaphy was carried out 7 months prior to the distal nerve repair. Biopsies were taken from the distal portions of the vascularized radial sensory nerve and the conventional sural nerve at the time of the second procedure. Histological evaluation demonstrated superior regeneration across the vascularized nerve graft. Subjectively, the patient described better sensory recovery in the territory innervated by the vascularized nerve graft. Sensory testing in the two territories demonstrated better sensibility in the territory innervated by the vascularized nerve graft.

Seven children ranging in age from 1 to 13 years (mean 8 years) were evaluated at a range of 8 months to 15 years (mean 4.7 years) following group fascicular repair of the median nerve at the wrist following a sharp transection of the nerve. At the follow-up evaluation, they were measured with Semmes-Weinstein nylon monofilaments, moving and static two-point discrimination, and were judged for the presence or absence of paresthesias in their hands. The children did not receive sensory reeducation in the postoperative period. All children recovered to normal levels of moving and static two-point discrimination and were free from disabling paresthesias. These results are contrasted with a group of similar nerve injuries in adult patients treated in the same way and over the same period of time. It is concluded that the capacity for peripheral neural regeneration and cerebral plasticity in children is such that excellent recovery of functional sensation in the hand can occur without the need for sensory reeducation.

Semmes-Weinstein nylon monofilaments are used to evaluate recovery of cutaneous pressure threshold in adults recovering from median nerve repair at the wrist level. Of the 46 patients studied, 22 received a program of sensory reeducation. The nylon monofilament measurements accurately described the improvement in recovered sensation following nerve repair. There was a statistically significant better recovery (lower threshold) in patients receiving sensory reeducation, which was present in those less than 30 years old (P less than .003) as well as those greater than 30 years old (P less than .05). However, normal thresholds were not recovered in these patient populations.

Three cases are reported to illustrate the potential danger of silicon-polymer intubulation of nerve for either nerve repair or following neurolysis. Since silicon-polymer intubulation of nerve is now a proven model for producing chronic nerve compression, its use clinically may be contraindicated where neural regeneration is the desired goal.