Acute nerve grafting in traumatic injuries: two case studies

Primary nerve grafting in traumatic injuries is rarely performed because of the uncertainty of the extent of injury, the limited availability of nerve grafts, and the damage to adjacent soft tissue. In this report the authors present two cases of acute nerve grafting after trauma-the first of the common peroneal nerve and the second of the ulnar nerve above the elbow-with sensory and motor recovery. Although compelling general arguments against primary posttraumatic nerve grafting exist, these cases illustrate that, in certain favorable and critical clinical situations, acute nerve grafting may be successful.

Regeneration through long nerve grafts in the swine model

We investigated regeneration across a long nerve defect in the swine model to study extensive neural loss and long nerve gap. Most experiments have been conducted in the rodent model that, while an appropriate immunological model, only allows short nerve gaps to be studied. Twelve outbred swine received either an 8-cm ulnar nerve autograft or an allograft without immunosuppression. At 6 and 10 months, histomorphometry of the autografts demonstrated excellent nerve regeneration, while very poor regeneration was noted across the allografts. This confirmed that 8 cm are an adequate challenge independent of the spontaneous regeneration potential of axons seen in rodents. The swine ulnar nerve graft model causes minimal morbidity and will now be used with immunological manipulation of inbred animals.

Nerve transplantation: a father's final gift

Offering the option of organ and tissue donation to grieving families may seem stressful, but asking the question may provide a positive means to extend care to the bereaved family and help others in return. Many donor families have said donation was an opportunity to make some sense out of a senseless situation and to relieve some of the grief they experienced. This article presents a case that started with such a discussion by ICU nurses in one of our donor hospitals, and ended with successful organ and tissue recovery and transplantation. As "routine" as this may sound, it was anything but routine--it made history.

Restoration of walking in paraplegia by transferring the ulnar nerve to the hip: A report on the first patient

There is no known way to make paraplegics walk when their spinal cord is completely transected. Many researchers worldwide have been developing different methods to solve this problem. We believe that transferring a sound nerve from the upper limb to the main muscles of the hip could help paraplegics to walk, although light orthotic devices would still be needed. We chose to transfer the ulnar nerve because it is the longest in the upper limb and can reach the glutei without grafts. In addition, palsy of the ulnar nerve can be repaired by classical reconstructive surgery. After many years of research in animals and after obtaining permission from the Ethical Committee of the National Health Surgery, we operated on three human beings bilaterally. The first patient is walking. Two are still recovering.

Nerve transfer to biceps muscle using a part of the ulnar nerve in brachial plexus injury (upper arm type): a report of 32 cases

Thirty-two patients with absent elbow flexion secondary to brachial plexus injury underwent nerve transfer using 1 or 2 fascicles of the ulnar nerve to the motor branch of the biceps muscle. Twenty-six patients had root avulsion injury of C5 and C6; 4 had root avulsion injury of C5, C6, and C7; and 2 had lateral and posterior cord injury with distal injury of the musculocutaneous nerve. The follow-up period ranged from 11 to 40 months (average, 18 months). Thirty patients had biceps strength of M4 (flexion power ranged from 0.5 to 7 kg) and 1 had biceps strength of M3. All but 1 patient demonstrated signs of recovery of the biceps muscle. No notable impairment of hand function was observed.

Rehabilitation after subcutaneous transposition of the ulnar nerve: immediate versus delayed mobilization

We studied 36 patients who had clinical signs and symptoms consistent with cubital tunnel syndrome and in whom nonoperative management failed. These patients underwent anterior subcutaneous transposition of the ulnar nerve followed by either immediate (20 patients) or delayed (16 patients) mobilization. All patients were evaluated with an outcomes assessment questionnaire, and 35 of the 36 were given repeat physical examinations. After surgery, there were no significant differences between the two groups in pain relief, weakness, or patient satisfaction (71% of the immediate mobilization group and 74% of the delayed group) were satisfied. Secondary quantitative outcomes such as grip strength, lateral pinch, or two-point discrimination were also not significantly different between the groups. Both groups had a statistically significant improvement in first dorsal interosseous and adductor pollicis muscle strength. In the immediate mobilization group, however, patients returned to work and resumed activities of daily living earlier (median 1 month) than patients in the delayed mobilization group (median 2.75 months). Therefore, we conclude that anterior subcutaneous transposition provides a high degree of satisfaction and relief of symptoms regardless of when mobilization is initiated. However, immediately mobilizing the patient significantly influenced how early the patient returned to work and resumed activities of daily living.

Systemization of the vascularization of the ulnar nerve in its upper arm

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.

Is axonal sprouting able to traverse the conjunctival layers of the peripheral nerve? A behavioral, motor, and sensory study of end-to-side nerve anastomosis

The repair of large peripheral nerve defects is not always possible, especially when the proximal stump is not available. In these cases, end-to-side nerve anastomosis has been proposed. In the present experiment, using the terminal branches of the rat brachial plexus, the authors studied behavioral responses after end-to-side nerve anastomoses using fibrin glue, 3 and 6 months after surgery. Rats were evaluated by results of a grasping test, a capsaicin test and a hot-plate test. The collected data demonstrated that there was no functional motor or sensory reinnervation after the end-to-side nerve anastomoses. The conjunctive layers of the peripheral nerve thus represented an effective barrier to reinnervation.

Split nerve grafting

Twenty-five patients with severe brachial plexus lesions (having a rather poor prognosis in general), were subjected to a variety of split nerve graft procedures, with 22 achieving useful functional recovery. Thirty-eight nerves were reconstructed, with 32 of them achieving useful recovery. Results in these patients were no better nor worse than those obtained with other types of nerve grafts (e.g., free cutaneous nerve grafts, vascularized nerve grafts, etc.). The technique of splitting the nerve for the use of split fascicle groups as free nerve grafts is nevertheless recommended as an alternative to the application of the ulnar nerve as a vascularized nerve graft. The plexiform arrangement of the fascicles within the ulnar nerve apparently does not preclude the possibility of harvesting sufficiently long nerve grafts.

A flap for segmental loss of a digital nerve. The Venkataswami flap revisited

The use of a V-Y advancement flap for reconstruction of a volar/lateral soft tissue defect in a digit involving segmental loss of the neurovascular bundle of up to 10 mm at middle phalangeal level is described. This flap allows immediate reconstruction with primary repair of the nerve and gives good functional results. Two cases are presented.

The rat brachial plexus and its terminal branches: an experimental model for the study of peripheral nerve regeneration

Despite the introduction of microsurgical techniques into clinical practice, the results of surgical procedures involving the brachial plexus and peripheral nerves are still far from spectacular. We therefore studied the rat brachial plexus and its terminal branches in 203 rats. Detailed anatomic and morphologic analyses of the biceps brachii and musculocutaneous nerve, finger flexors, flexor carpi radialis, and the median nerve were performed. Various sources of conventional and vascularized nerve grafts were explored. After musculocutaneous nerve section or median nerve section, there were no articular contractures or automutilations, which constitutes an advantage for these experimental models over the sciatic nerve model. The brachial plexus and its terminal branches provide a good experimental model which can be used to assess the development and normal control of muscle function, examine the mechanisms underlying functional recovery, and test the effects of treatments to enhance recovery.

Intercondylar fractures of the distal humerus: routine anterior subcutaneous transposition of the ulnar nerve in a posterior operative approach

Intercondylar fractures of the distal humerus in adults are rare and notoriously difficult to treat. The goals of open reduction are to preserve the articular surface and restore elbow function. We treated 20 patients by open reduction with dual-plate internal fixation and routine anterior subcutaneous transposition of the ulnar nerve. The follow-up period ranged from 15 to 35 months. The fractures were classified according to Muller's system. The results were evaluated using the Cassebaum rating system and subjective functional status. Excellent or good results were achieved in 15 elbows (75%), two had a fair result, and three, poor. A clearer understanding of fracture patterns, rigid dual-plate internal fixation, and early rehabilitation are needed to improve the results from this vexing injury. We recommended routine ulnar nerve anterior subcutaneous transposition using a posterior approach. Compared with published reports, our preliminary results demonstrated no postoperative ulnar nerve compression syndrome at follow-up. Routine anterior subcutaneous transposition of the ulnar nerve to avoid the postoperative ulnar nerve compression syndrome is required.

Cross-chest C7 nerve grafting followed by free muscle transplantations for the treatment of total avulsed brachial plexus injuries: a preliminary report

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.

Functional restoration of elbow flexion in brachial plexus injuries: results in 167 patients (excluding obstetric brachial plexus injury)

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.

[Morphometric rationale for utilization of peripheral nerves of the human fetus as vascularized allografts]

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.

Enzymhistochemical evaluation of ulnar nerve grafts in brachial plexus lesions

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.

Comparison of one- and two-stage nerve grafting of the rabbit median nerve

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.

Muscle transfers in brachial plexus lesions

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.

Island pedicled nerve grafts

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.

[Comments on vascular pedicled nerve transplantation in the area of the upper extremity]

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.

Experience with the free vascularized ulnar nerve graft in repair of supraclavicular lesions of the brachial plexus

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.

The ulnar nerve as vascularized nerve transplant. Part I: Anatomy: arterial vascular supply

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.

Contemporary treatment of peripheral nerve and brachial plexus lesions

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.