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The number of donor nerves available for nerve transfer in the reconstruction of total root avulsion injuries of the brachial plexus is always insufficient. Use of the contralateral normal C7 cervical nerve as a donor nerve is a new approach to obtain more nerve fibers but also is a controversial procedure. Fifteen patients with total root avulsion of the brachial plexus received cross-chest C7 nerve grafting as the first stage of reconstruction. Eight of these patients, after an interval of 11 to 20 months, had free muscle transplantations (one to three muscles transferred per individual) to the affected limb. A long period of rehabilitation (at least 2 years) is required. The donor limbs of the 15 patients showed negligible deficits of motor and sensory function. Although independent movement of the transferred muscles from the contralateral limb has not been achieved, useful function of the reconstructed limb is possible. The preliminary results are encouraging.

From 1985 to 1990, 167 patients were treated for impaired elbow flexion caused by brachial plexus injury. Surgical procedures were divided into two categories: nerve reconstruction (128 patients) and muscle or tendon transfers (39 patients). Surgery in the nerve reconstruction group included direct suturing, nerve grafting of portions of the brachial plexus responsible for elbow flexion, or nerve transfer (intercostal, phrenic, or spinal accessory nerve) to the musculocutaneous nerve. The second category included tendon or muscle transfer or a functioning free muscle transplantation for biceps replacement. Results were assessed by the Medical Research Council grading system and weight-lifting evaluation. Functional results revealed that nerve reconstruction was superior to muscle tendon transfers, direct suturing was superior to nerve grafting, short nerve grafts (< 10 cm) were superior to long nerve grafts (> 10 cm), infraclavicular plexus injuries did better than supraclavicular injuries, vascularized ulnar nerve grafts (if indicated) were superior to conventional long nerve grafts, ruptured plexus injuries recovered better than root avulsions. Intercostal nerve transfer to the musculocutaneous nerve has satisfactory results. In the muscle tendon transfer group, Steindler flexorplasty resulted in upgrading muscle strength from level one to level two. Functioning free muscle transplantation had results similar to the latissimus dorsi transfer.

The authors performed morphometric section studies of the peripheral nerves of 25 human fetuses of 17-26 week development. The purpose of the study was determination of the technical possibility of using revascularized nerves of the human fetus as grafts for replacement of post-traumatic defects in the peripheral nerves. The peripheral nerves of the upper limbs of fetuses of the indicated developmental periods were found to be formed morphologically. The results of morphometric study showed that it is technically possible to obtain the median, ulnar, and radial nerves on a vascular pedicle. The length and diameter of the vessels of the vascular pedicle of the upper limb peripheral nerves allow revascularization of the brephograft to be accomplished by means of microsurgical techniques.

Our concept for the reconstruction of brachial plexus injuries includes an intercostal nerve transfer to the vascularized ulnar nerve graft. A free neurovascular latissimus dorsi is then transferred in a second stage operation. For optimization of the regeneration result, the operative planning of the second step includes nerve biopsies and enzymhistochemical evaluation for the distribution of motor axons. The staining method according to Scabolcz et al. is described and clinical cases are presented.

The hypothesis that improved axonal regeneration occurs through nerve grafts when scarred tissue is removed and distal coaptation completed during a delayed, secondary operation was tested in a rabbit model. The ulnar nerve was used as a donor nerve graft to a final three-centimeter deficit of the contralateral median nerve. This was done either in one stage or in two stages, with resection of scar and coaptation at the distal site done ten weeks later. Evaluation included nerve conduction velocity, compound action potential area, muscle contraction force, muscle weight, and axon counts. Two-stage nerve grafts at 24 weeks were significantly inferior to one-stage grafts only in compound action potential area. Both nerve grafts showed significant improvement in function from twenty-four to sixty-two weeks as measured by nerve conduction velocity; two-staged grafts in addition showed a significant increase in compound action potential area and twitch contraction force. The data are inconclusive regarding the absolute superiority of two-stage versus one-stage grafting. Different timing for the second stage may be required.

With the use of ulnar nerves of cynomolgus monkeys, the present study examined whether basal laminae of Schwann cells can serve as conduits for regenerating axons in nerve allografts from non-human primates. A segment of ulnar nerve was transected distal to the elbow joint one week before grafting. In Group A, a distal segment of the transected nerve was transplanted, after freezing and thawing, into the ulnar nerve of another monkey, at a level that corresponded to that from which the graft was taken. In Group B (the control group), the segment of nerve was grafted in the same manner but without cryotreatment. Two weeks, five weeks, eight weeks, and five months after grafting, the graft and the host nerve were examined with light and electron microscopy. Within two weeks after grafting in Group A, after degradation of the cellular components of the Schwann cells, the basal laminae of the Schwann cells were intact in the form of tubes. Within five weeks, many regenerating axons grew out into these basal lamina tubes in the three-centimeter-long grafts and extended into the host nerve. As seen at the wrist (seven centimeters from the distal suture) five months after grafting, the axons exhibited fully mature myelination both in the graft and in the host nerve. In contrast, in Group B, in which the Schwann cells had not been disrupted by cryotreatment, cellular components and connective-tissue matrices, including basal laminae, had been degraded and had been replaced by invading cells, which filled the endoneurial spaces of the graft. Five months after grafting, axonal growth had been arrested in the graft one centimeter distal to the proximal suture. The beneficial effect in Group A appears to have been the result of the retention and preservation of intact basal laminae of Schwann cells after rapid removal of killed Schwann cells and myelin debris. Killing of Schwann cells by freezing before grafting may abolish the immune response to the Schwann cells in allografts and lead to fragmentation and disruption of myelin, which facilitates the rapid removal of myelin by macrophages.

Authors used to cover the defect of the wrist region in consequence of electric burn reverse ulnar artery island flap with success. The method described was used in one case and it is suggested in similar circumstances.

The concept of reconstruction to regain lost function after brachial plexus lesions has to be as broad and complex as possible. We have been exploring wider and more novel clinical concepts at the Clinic of Plastic, Hand, and Reconstructive Surgery at the Medical School of Hannover. Our ideas are supported by experience in 160 patients. We have attempted to combine the use of a vascularized nerve graft and a microvascularly-transferred autologous muscle. Patients undergoing the procedures have included those with late complete root avulsions and no functional return, as well as previously operated cases with poor recovery of biceps, wrist, and forearm function. The surgery is divided into two stages. In the first stage, the ulnar nerve is prepared as a vascularized nerve graft and is sutured to intercostal nerves 3 to 5 or 6. In stage 2, when the Tinel sign reaches the distal ends of the ulnar nerve graft (about six to eight months later), the latissimus dorsi muscle is harvested. The muscle is then placed as far distally as possible in the forearm and sutured to the deep finger flexors and flexor pollicis longus. Proximally, the insertion is performed similarly to Steindler's method. The vessels are connected to the brachial artery and vein and the thoracodorsal nerve is sutured to the graft. This method provides flexion of both the fingers and the elbow.

77 patients with an isolated traumatic ulnar nerve lesion were operated on between 1972 and 1982. 40 patients with more than 18 months of follow-up were reviewed with a new clinical quoting. 37.5 p. cent of satisfactory results were achieved with nerve sutures done in emergency, 56.3 p. cent with secondary nerve grafting. Factors influencing the results were age, level of the lesion and use of the microscope. 80 p. cent of the patients recovered a protective sensibility, but only one third discrimination. Patients considered sensory deficit as little cumbersome. Wartenberg's sign was noticed in 60 p. cent of our patients and a claw hand in 46 p. cent. Power grip was only 70 p. cent of the contralateral hand due to poor interosseous muscle recovery. The main disability was an instable thumb metacarpophalangeal joint in 70 p. cent. Subterminal pinch grip was weak and was improved by the transfer of the flexor digitorum superficialis of the ring finger. Cold hypersensitivity was noticed in 73 p. cent of our patients, but its frequency diminished with sensory recovery. Motor deficiencies were the most important and required early tendon transfers in older patients.

The use of articular branch of the dorsal sensory ulnar nerve as a nerve graft is discussed. A case of traumatic neuroma of the dorsal ulnar nerve which was treated by this method is presented.

By avoiding tension and securing anatomical neurorrhaphy, regeneration of nerve is obtainable. When the gap exceeds a certain limit, the only way to avoid tension is the use of grafts. Experience in animal experiments and clinical practice has demonstrated that regenerating axons can cross 2 optimal suture lines much more easily than one sub-standard one. For bridging a gap autografts are used, because in autografts the fascicular pattern is preserved and its Swann cells survive. With the interfascicular technique the dissection of the nerve stumps proceeds from normal to abnormal tissues and the epineurium is resected. The coaptation must be exact so that the grafts cover the whole cross sectional area of the fascicle. All this can be achieved by the use of one 10--0 or 11--0 nylon suture. The clinical results show that in the median nerve 82%, in the ulnar 80% and in the radial nerve 92% of good functional results can be obtained. Also in brachial plexus injuries the interfascicular nerve grafting procedure opened new ways. Therefore interfascicular nerve grafting, using autografts in cases of nerve repair, where a gap may occur, currently is the method of choice.

Nerve grafting has made advances in the last 100 years. One of the most significant of these was realizing the importance of adequate blood supply for successful nerve grafting. The vascular anatomy of the six potential vascularized donor nerves we have reviewed may prove to be extremely useful in reconstructing proximal nerve lesions, large nerve defects, and compromised recipient beds.

A review of 53 dissections associated with injections and radiographs was performed (by the authors) to specify the arteriovenous vascularization of the ulnar nerve of the arm. An arteriovenous pedicle is constantly to be found. The artery "collateralis ulnaris superior" arises from the inferior border of the "pectoralis major" at an average distance of 6,7 cm. The arterial depending vein most often directly rejoins the "vena brachialis" lower than "vena basilica" does, but usually more distally than the arterial emergence level. Thus constituted, the pedicle can be anastomosed, measuring generally more than 1 mm in diameter. The arterial distribution originates from an arcade parallel to the nerve from which arise some extremely fine ladderlike vessels. Finally, this pedicle vascularizes the whole brachial part of the nerve (roughly 23,6 cm).

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.

A primate model was developed to study the effect of submuscular versus intramuscular placement upon the development of ulnar nerve fibrosis. No significant adherence was found in either location between the ulnar nerve and the flexor-pronator muscle mass. There was no significant difference in the mean nerve fibre diameter or in the percent neural tissue between the ulnar nerves in the two different locations. It is suggested that it is the interaction of the transposed ulnar nerve with other fibrous anatomical structures proximal to, across, and distal to the elbow that causes failure in ulnar nerve transposition procedures, rather than an adverse reaction between the incised flexor-pronator muscle mass and the ulnar nerve.

Vascularized free nerve grafts make possible the repair of extensive defects of large nerve trunks. Since the original observations of Taylor and Ham in 1976 many cases have been published. The ulnar nerve in the upper arm in most cases has a simple arteriovenous pedicle the anatomy of which has been precisely defined by cadaver dissections and intravascular injections. The arterial supply, 47 times out of 50, is the proximal ulnar collateral and 2 times the distal collateral ulnar artery. It takes its origin from the medial side of the brachial artery in the upper or middle third of the arm. Its external diameter is on the average 1.8 mm at its origin. The accompanying vein enters a brachial vein 2 to 3 cm below the origin of the artery. The removal of the graft is done through a straight incision on the inner aspect of the arm. The brachial artery is dissected from above downward and its medial branches noted. The nerve and its arteriovenous pedicle are separated in a block along with adjacent cellular tissue by dissection from below upwards. The average length of the pedicle thus produced is 13 cm, but a much longer section of the nerve can certainly be taken. A case report illustrates the procedure.

A technique of nerve grafting is described whereby a nerve "graft" is raised, maintaining its blood supply via a vascular pedicle. It is then transposed to reconstruct a defect in an adjacent nerve. Although there is little clinical evidence that this technique results in better nerve regeneration when compared with conventional nerve grafting, the method has advantages which are discussed.

The vast majority of severe traumatic lesions of the brachial plexus are due to road accidents. Surgical intervention is indicated in cases of persistent motor and sensory loss. The operation should be performed one to three months after the traumatic event. Indications and results of neurolysis, autologous nerve grafts, and neurotization are reported. Neurolysis was employed 43 times on 36 patients primarily to relieve pain rather than to restore function. Autologous nerve grafting was employed in 100 patients and can give good results when the lesion involves the three upper roots. Neurotization using Bell's nerve was used in 46 patients as a source of axons to re-establish the nervous pathways of the destroyed suprascapular or musculocutaneous nerves.

The ulnar nerve is supplied basically by the arteries accompanying it in its various locations: in the axillary section, by a branch of the lateral thoracic artery or directly by the axillary artery; in the upper arm, by branches originating from the collateral ulnar superior artery; in the supracondylar section and in the region of the groove for the ulnar nerve, by branches originating from the anastomosis of the collateral arteries and the posterior branch of the recurrent ulnar artery; and in the forearm, by branches of the recurrent ulnar artery and the ulnar artery. Venous return is by the venae comitantes. Since the ulnar nerve possesses a good arterial supply, it may be used with different techniques as a vascularized nerve transplant in traumatic lesions of the brachial plexus, to repair more important missing nerve paths.

The treatment consisted of a free vascularized ulnar nerve graft in 63 patients with lesions of the supraclavicular brachial plexus. Since 1978, the outcome in 42 patients with a minimum follow-up period of 30 months was certainly better than with an avascular segment of ulnar nerve. Clear proof of hopeless prognosis for recovery along the course of the ulnar nerve is essential before using this graft. The early operations used the ulnar artery and accompanying veins as the pedicle for the graft; later a technique using collateral vessels in the arm has been favored. Although functional elbow flexion has been regained in the majority of patients, recovery of function into the hand has been disappointing. Although it cannot be proved that results are better than when conventional sural nerve grafts are performed, the authors believe that this is the case. The vascularized ulnar nerve graft (VNG) is indicated in more severe injuries of the brachial plexus, where preganglionic injury to the eighth cervical and first thoracic nerves is proven, where the gap between nerve stumps is long, and when the presence of two or three proximal stumps allows the opportunity for extensive repair.

Nerve pedicle grafts in the upper limb were performed on nine patients with Volkmann's Ischaemia. Long-term follow-up of three cases has shown that the results of this operation are successful. Sensory and motor recovery of the median nerve occurs and consequently useful hand function is regained. Since Volkmann's Ischaemic contracture is not rare in developing countries, this operation should be the treatment of choice when the median and ulnar nerves have been damaged beyond hope of recovery.

This article describes the vascular anatomy of several nerves of the upper extremity with a view of their potential use as pedicled, vascularized nerve grafts.

The authors present a method of surgical treatment of progressive paresis of the ulnar nerve by means of transposition of this nerve to the anterior aspect of the cubital fossa. This method was used in 35 cases. The most frequent cause of the paresis was old fracture or contusion of the region of the cubital joint. In all cases the therapeutic result was good.

The dorsal sensory branch of the ulnar nerve has been found to have the appropriate size and sufficient length for use as a digital nerve graft. This donor nerve was utilised fifteen times in twelve patients for the bridging of defects in thirteen digital nerves of the fingers. After an average follow-up of 23.2 months, only one patient failed to achieve any two point discrimination in the area supplied by the involved digital nerve. The other eleven patients had an average two point discrimination of 9.5 mm with a range of 5 to 18 mm. Painful neuroma formation or loss of hand function related to the use of the dorsal sensory branch of the ulnar nerve as a donor for digital nerve grafts was not encountered.