Contralateral L-6 nerve root transfer to repair lumbosacral plexus root avulsion: experimental study in rhesus monkeys.

OBJECT: Nerve transfer is used for brachial plexus injuries but has rarely been applied to repairs in the lower extremities. The aim of this study was to evaluate the feasibility and effectiveness of using the contralateral L-6 nerve root to repair lumbosacral plexus root avulsions. METHODS: Eighteen rhesus monkeys were randomized into 3 groups. In the experimental group, the left L4-7 and S-1 nerve roots were avulsed and the right L-6 nerve root was transferred to the left inferior gluteal nerve and the sciatic nerve branch innervating the hamstrings. In the control group, the left L4-7 and S-1 nerve roots were avulsed and nerve transfer was not performed. In the sham operation group, the animals underwent a procedure that did not involve nerve avulsion and nerve transfer. Functional outcomes were measured by electrophysiological study, muscle mass investigation, and histological study. RESULTS: The mean amplitudes of the compound muscle action potentials from the gluteus maximus and biceps femoris in the experimental group were higher than those in the control group but lower than those in the sham group (p < 0.05). The muscle mass and myofiber cross-sectional area of these muscles were heavier and larger than those in the control group (p < 0.05). The number of myelinated nerve fibers of the inferior gluteal nerve and the branch of the sciatic nerve innervating the hamstrings in the control group was significantly smaller than the number in the experimental and sham groups (p < 0.01). CONCLUSIONS: In this animal model, the contralateral L-6 (analogous to S-1 in humans) nerve root can be used to repair lumbosacral plexus root avulsion.

Brachial plexus injury: the London experience with supraclavicular traction lesions.

In this article, the author details the experiences of his hospital and other London hospitals in treating brachial plexus injury. As noted, important advances have been made in methods of diagnosis and repair. Myelography was replaced by CT scan and later by MRI. Among the topics the author explores are diagnosis (including pain, the presence or absence of the Tinel sign, and the irradiation of pins and needles) and the principles of repair. The author emphasizes that it is imperative that ruptured nerves be repaired as soon as possible, with the closed traction lesion coming, in urgency, close behind reattachment of the amputated hand or repair of a great artery and a trunk nerve in the combined lesion. Finally, the article concludes that the surgeon must be actively engaged in the whole process of rehabilitation and treatment of pain. This is part of a Point-Counterpoint discussion with Dr. David G. Kline's presentation of "A Personal Experience."

Nerve transfers for severe nerve injury.

Nerve transfers are becoming used increasingly for repair of severe nerve injures, especially brachial plexus injuries, where the proximal spinal nerve roots have been avulsed from the spinal cord. The procedure essentially involves the coaptation of a proximal foreign (donor) nerve to the distal denervated (recipient) nerve, so that the latter's end-organs will be reinnervated by the donated axons. Cortical plasticity appears to play an important physiologic role in the functional recovery of the reinnervated muscles. This article provides the indications for nerve transfer, principles for their use, and a comprehensive survey on various intraplexal and extraplexal nerves that have been used for transfer to repair clinical nerve injuries. Specific transfers to reanimate muscles denervated by the common patterns of brachial plexus are emphasized, including expected clinical outcomes based on the existing literature.

Sural nerve grafting for long defects of the femoral nerve after resection of a retroperitoneal tumour.

Most injuries to the femoral nerve are iatrogenic in origin and occur during resection of large retroperitoneal tumours. When the defect is considerable a nerve graft is mandatory to avoid tension across the suture line. We describe two cases of iatrogenic femoral nerve injury which recovered well after reconstruction with long sural nerve grafts. The probable reasons for success were that we performed the grafting soon after the injury, the patients were not too old, the nerve repairs were reinforced with fibrin glue and electrical stimulation of the quadriceps was administered to prevent muscle atrophy. Good functional results may be obtained if these conditions are satisfied even if the length of a nerve graft is more than 10 cm.

Did the partial contralateral C7-transfer fulfil our expectations? Results after 5 year experience.

OBJECTIVE: Within the last decade contralateral C7-transfer has become a new source of axon donor in complete brachial plexus lesions. METHODS: Ten adult patients with a complete posttraumatic brachial plexus lesion and a follow-up of more than 5 years are analyzed. As shown by GU we are using a two stage procedure with exploration and extraplexuel neurotization of the suprascapular nerve using 1/2 spinal acessory nerve. Depending on the intraoperative findings, the musculocutaneous nerve is neurotized by the phrenic nerve at the time of primary operation or secondarily neurotized by the contralateral C7 root. If the musculocutaneous nerve could be neurotized by the phrenic nerve, C7-transfer is used to reinnervate the median nerve. If ever possible, the vascularized ulnar nerve graft or if not availabe two sural nerves are used. Neurotization of the musculocutaneous nerve was carried out in 6, and of the median nerve in 4 patients. There are 6 patients in the MC group and 4 patients in the Median group. Criterias for evaluation used are: donor site (morbidity, classification), time for recovery, time for autonomization, and functional result. Successful elbow flexion is achieved if muscle power > M3, successful median nerve motor function is achieved if a primitive power grip pattern is achieved. RESULTS: All patients were complaining of temporary paresthesia in the dorsal part of P3 of the thumb, index and middle finger. There was complete sensory at the 3-month postoperative examination. There was no evident clinical motor loss at the donor extremity. A successful elbow flexion, i.e. muscle power > M3 was achieved in all 6 patients after 9-15 months. 4 of 6 patients are able to use this function individually. In the other two patients a start command must be given voluntarily from the contralateral side (contraction of the contralateral latissimus dorsi muscle). A functional primitive grip pattern could be achieved in 1 out of 4 patients after 18 months. In three patients, although there is movement, this mouvement must be judged "academic" at the present state. CONCLUSIONS: The C7-transfer proved to be a safe transfer if at the time of operation no fascicles innervating wrist and finger extension are taken. Provided adequate biceps muscle organ function, active elbow flexion can be reconstructed in most of the patients. However, for median nerve reinnervation motor results are moderate up to now.

Repair of peripheral nerve defects by controlled distraction: a preliminary study.

Five cats underwent a 3.0-cm removal of their ulnar nerves followed by delayed repair. One limb received a standard cable grafting procedure, and the other side had the proximal nerve stump lengthened by controlled distraction and a subsequent direct anastomosis. Histological examination of the lengthened nerves revealed better quality than the grafted nerves in all cats. Nerve conduction velocity of the lengthened side was greater than the graft side in three cats. It appears that this technique of nerve lengthening and direct repair might have clinical applicability.

[Direct muscular neurotization]. / La neurotisation musculaire directe.

The authors present a technique of direct muscular neurotization consisting of re-innervation by direct implantation of a nerve into one or several muscles in cases of avulsion of the nerve supplying the muscle or traumatic or surgical avulsion of the neural part of the muscle. The biological basis for this operation is that a denervated muscle can accept a new innervation by a foreign nerve even in an aneural zone because its sensitivity to acetylcholine is present throughout the muscle, while, in a normally innervated muscle, sensitivity to acetylcholine is confined to the motor endplates. The results of 47 cases are presented: 42 of them obtained good or very good results.