The long thoracic nerve as a donor for facial nerve reanimation procedures: cadaveric feasibility study: laboratory investigation

OBJECT: Injury of the facial nerve with resultant facial muscle paralysis may result in other significant complications such as corneal ulceration. To the authors' knowledge, neurotization to the facial nerve using the long thoracic nerve (LTN), a nerve used previously for neurotization to other branches of the brachial plexus, has not been explored previously. METHODS: In an attempt to identify an additional nerve donor candidate for facial nerve neurotization, 8 adult human cadavers (16 sides) underwent dissection of the LTN, which was passed deep to the clavicle and axillary neurovascular bundle. The facial nerve was localized from the stylomastoid foramen onto the face, and the distal cut end of the previously dissected LTN was tunneled to this location. Measurements were made of the length and diameter of the LTN. Long thoracic nerve innervation to the first and second digitations of the serratus anterior was maintained on all sides. RESULTS: All specimens were found to have an LTN with more than enough length to be tunneled superiorly, tension-free to the extracranial facial nerve. Connections remained tensionless with left and right head rotation of up to 45 degrees . The mean length of this part of the LTN was 18 cm with a range of 15-22 cm. The overall mean diameter of this nerve was 2.5 mm. No evidence of injury to the surrounding neurovascular structures was identified on gross examination. CONCLUSIONS: To the authors' knowledge, the LTN has not been previously examined as a donor nerve for facial nerve reanimation procedures. Based on the results of this cadaveric study, the use of the LTN may be considered for such surgical maneuvers.     

The contralateral long thoracic nerve as a donor for upper brachial plexus neurotization procedures: cadaveric feasibility study

Object Various donor nerves, including the ipsilateral long thoracic nerve (LTN), have been used for brachial plexus neurotization procedures. Neurotization to proximal branches of the brachial plexus using the contralateral long thoracic nerve (LTN) has, to the authors' knowledge, not been previously explored. Methods In an attempt to identify an additional nerve donor candidate for proximal brachial plexus neurotization, the authors dissected the LTN in 8 adult human cadavers. The nerve was transected at its distal termination and then passed deep to the clavicle and axillary neurovascular bundle. This passed segment of nerve was then tunneled subcutaneously and contralaterally across the neck to a supra- and infraclavicular exposure of the suprascapular and musculocutaneous nerves. Measurements were made of the length and diameter of the LTN. Results All specimens were found to have a LTN that could be brought to the aforementioned contralateral nerves. Neural connections remained tension free with left and right neck rotation of ~ 45 degrees . The mean length of the LTN was 22 cm with a range of 18-27 cm. The overall mean diameter of this nerve was 3.0 mm. No gross evidence of injury to surrounding neurovascular structures was identified in any specimen. Conclusions Based on the results of this cadaveric study, the use of the contralateral LTN may be considered for neurotization of the proximal musculocutaneous and suprascapular nerves.     

The nerve to the mylohyoid as a donor for facial nerve reanimation procedures: a cadaveric feasibility study

OBJECT: Facial nerve injury with resultant facial muscle paralysis is disfiguring and disabling. Reanimation of the facial nerve has been performed using different regional nerves. The nerve to the mylohyoid has not been previously explored as a donor nerve for facial nerve reanimation procedures. METHODS: Five fresh adult human cadavers (10 sides) were dissected to identify an additional nerve donor candidate for facial nerve neurotization. Using a curvilinear cervicofacial skin incision, the nerve to the mylohyoid and facial nerve were identified. The nerve to the mylohyoid was transected at its point of entrance into the anterior belly of the digastric muscle. Measurements were made of the length and diameter of the nerve to the mylohyoid, and this nerve was repositioned superiorly to the various temporofacial and cervicofacial parts of the extracranial branches of the facial nerve. All specimens had a nerve to the mylohyoid. The mean length of this nerve available inferior to the mandible was 5.5 cm and the mean diameter was 1 mm. In all specimens, the nerve to the mylohyoid reached the facial nerve stem and the temporofacial and cervicofacial trunks without tension. No gross evidence of injury to surrounding neurovascular structures was identified. CONCLUSIONS: To the authors' knowledge, the use of the nerve to the mylohyoid for facial nerve reanimation has not been explored previously. Based on the results of this cadaveric study, the use of the nerve to the mylohyoid may be considered for facial nerve reanimation procedures.     

Endoscopically assisted decompression of the suprascapular nerve in the supraspinous fossa: a cadaveric feasibility study. Laboratory investigation

OBJECT: The suprascapular nerve may become entrapped as it travels deep to the suprascapular ligament, necessitating decompression. The present study was performed to verify the feasibility of a minimally invasive, endoscopically assisted technique for decompressing the suprascapular nerve in the supraspinous fossa. METHODS: The authors performed dissection and decompression of the suprascapular ligament using an endoscopically assisted technique via a 3-cm skin incision in 10 adult cadavers (20 sides). Measurements were also made of the depth from the skin to the suprascapular ligament. RESULTS: A mean depth of 4 cm was necessary to reach the suprascapular ligament from the skin surface. With the authors' approach, no obvious injury occurred to the suprascapular or other vicinal neurovascular structures (such as the spinal accessory nerve and suprascapular vessels). CONCLUSIONS: The results of this cadaveric study demonstrate that access to the suprascapular nerve can be obtained endoscopically via a small suprascapular incision. This approach obviates a large incision, entry into the glenohumeral joint, and reduces the risk of spinal accessory nerve injury in the posterior cervical triangle, or atrophy of the trapezius or supraspinatus muscles from a standard larger dissection. To the authors' knowledge an endoscopically assisted approach to decompressing the suprascapular nerve as it courses deep to the suprascapular ligament has not been reported previously.     

Quantitation of the lower subscapular nerve for potential use in neurotization procedures

OBJECT: New information regarding nerve branches of the brachial plexus can be useful to the surgeon performing neurotization procedures following patient injury. Nerves in the vicinity of the axillae have been commonly used for neural grafting procedures, with the exception of the lower subscapular nerve (LSN). METHODS: The authors dissected and measured the LSN in 47 upper extremities (left and right sides) obtained in 27 adult cadavers, and determined distances between the LSN and surrounding nerves to help quantify it for possible use in neurotization procedures. The mean diameter of the LSN was 2.3 mm. The mean length of the LSN from its origin at the posterior cord until it branched to the subscapularis muscle was 3.5 cm, and the mean distance from this branch until its termination in the teres major muscle was 6 cm. Therefore, the mean length of the entire LSN from the posterior cord to the teres major was 9.5 cm. When the LSN was mobilized to explore its possible use in neurotization, it reached the entrance site of the musculocutaneous nerve into the coracobrachialis muscle in all but three sides and was within 1.5 cm from this point in these three. In the other specimens, the mean length of the LSN distal to this site of the musculocutaneous nerve was 2 cm. The mobilized LSN reached the axillary nerve trunk as it entered the quadrangular space in all specimens. The mean length of the LSN distal to this point on the axillary nerve was 2.5 cm. Furthermore, on all but one side the LSN was found within the confines of an anatomical triangle previously described by the authors. CONCLUSIONS: The authors hope that these data will prove useful to the surgeon for both identifying the LSN and planning for potential neurotization procedures of the brachial plexus.     

Quantitation of and landmarks for the muscular branches of the ulnar nerve to the forearm for application in peripheral nerve neurotization procedures

OBJECT: In neurotization procedures, donor nerves--either whole or in part-with relatively pure motor function can be carefully chosen to provide the optimal nearby motor input with as little donor site morbidity as possible. In this context, the ulnar nerve branches to the forearm muscles are relatively dispensable; however, quantitation of and landmarks for these branches are lacking in the literature. METHODS: The ulnar branches to the flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP) muscles in 20 upper extremities obtained in adult cadaveric specimens were dissected and quantified. In the forearm, a mean of four nerve branches led to the FCU and FDP muscles. A mean of 3.4 branches led to the FCU muscle; of these, one to three were medial branches and zero to two were lateral. Medial branches to the FCU muscle originated a mean of 2.7 cm inferior to the medial epicondyle. Lateral branches to the FCU muscle originated at a mean of 3.3 cm inferior to the medial epicondyle. The mean length of the medial branches was 3.2 cm, whereas the mean length of the lateral branches was 3.3 cm. All nerves had a single trunk for the FDP muscle, and in all specimens this branch was located deep to the main ulnar nerve trunk, originating from the ulnar nerve a mean of 2.7 cm inferior to the medial epicondyle. These branches had a mean length of 5.6 cm. The mean diameter of all medial and lateral branches to the FCU muscle was 1 mm, and the mean diameter of the branch to the FDP muscle was 2.1 mm. All branches to both the FCU and FDP muscles arose from the ulnar nerve, over its first approximately 5 cm from the level of the medial epicondyle. Additionally, all branches could be easily lengthened by gentle proximal dissection from the main ulnar nerve. CONCLUSIONS: Ulnar branches to the forearm can be easily localized and used for neurotization procedures. The branch to the FDP muscle had the greatest diameter and longest length, easily reaching the median nerve and posterior interosseous nerve via a transinterosseous membrane tunneling procedure. Furthermore, this branch could be teased away from the main ulnar nerve trunk and made to reach the distal branches of the musculocutaneous nerve in the arm.     

Hemihypoglossal nerve transfer in brachial plexus repair: technique and results

OBJECTIVE: In multiple avulsions of the brachial plexus, the search for extraplexal donor nerves in the hope of achieving motor neurotization is a major goal. We explored the possibility of using the hypoglossal nerve as a transfer point to reanimate muscles in the upper limb. METHODS: The hypoglossal nerve was used as a donor nerve for neurotization in seven patients with avulsive injuries of the brachial plexus. The surgical technique--an end-to-side microsuture using approximately half of the nerve fascicles--is basically the same as that used in the hypoglossal nerve-facial nerve jump graft, which is a well-known technique in facial nerve reanimation. The recipient nerves were the suprascapular (two patients), the musculocutaneous (one patient), the posterior division of the upper trunk (two patients), and the medial contribution to the median nerve (two patients). RESULTS: In spite of a connection documented by electromyography and selective activation in three of seven patients, the functional results in our patients were extremely disappointing: no patient had an outcome better than M1 in the reinnervated muscles. CONCLUSION: This technique was of no help to the patients and thus has been abandoned at our institution.     

Evaluation of suprascapular nerve neurotization after nerve graft or transfer in the treatment of brachial plexus traction lesions

OBJECT: The aim of this retrospective study was to evaluate the restoration of shoulder function by means of suprascapular nerve neurotization in adult patients with proximal C-5 and C-6 lesions due to a severe brachial plexus traction injury. The primary goal of brachial plexus reconstructive surgery was to restore biceps muscle function and, secondarily, to reanimate shoulder function. METHODS: Suprascapular nerve neurotization was performed by grafting the C-5 nerve in 24 patients and by accessory or hypoglossal nerve transfer in 29 patients. Additional neurotization involving the axillary nerve was performed in 18 patients. Postoperative needle electromyography studies of the supraspinatus, infraspinatus, and deltoid muscles showed signs of reinnervation in most patients; however, active glenohumeral shoulder function recovery was poor. In nine (17%) of 53 patients supraspinatus muscle strength was Medical Research Council (MRC) Grade 3 or 4 and in four patients (8%) infraspinatus muscle power was MRC Grade 3 or 4. In 18 patients in whom deltoid muscle reinnervation was attempted, MRC Grade 3 or 4 function was demonstrated in two (11%). In the overall group, eight patients (15%) exhibited glenohumeral abduction with a mean of 44 +/- 17 degrees (standard deviation [SD]; median 45 degrees) and four patients (8%) exhibited glenohumeral exorotation with a mean of 48 +/- 24 degrees (SD; median 53 degrees). In only three patients (6%) were both functions regained. CONCLUSIONS: The reanimation of shoulder function in patients with proximal C-5 and C-6 brachial plexus traction injuries following suprascapular nerve neurotization is disappointingly low.     

Contralateral C7 nerve root transfer to neurotize the upper trunk via a modified prespinal route in repair of brachial plexus avulsion injury

Purpose: In this report, we present our experience on the repair of brachial plexus root avulsion injuries with the use of contralateral C7 nerve root transfers with nerve grafting through a modified prespinal route. Methods: The outcomes of the contralateral C7 nerve root transfer to neurotize the upper trunk and C5/C6 nerve roots of the total or near total brachial plexus nerve root avulsion injury in a series of 41 patients were evaluated. The contralateral C7 nerve root that was dissected to the distal end of the divisions, along with the sural nerve graft, were placed underneath the anterior scalene and longus colli muscles, and then passed through the retro‐esophageal space to neurotize the recipient nerve. The mean length of the dissected contralateral C7 nerve root was 6.5 ± 0.7 cm, and the mean length of sural nerve graft was 6.8 ± 1.9 cm. The suprascapular nerve was neurotized additionally by the phrenic nerve or the terminal motor branch of accessory nerve in some patients. Results: The mean length of the follow‐up was 47.2 ± 14.5 months. The muscle strength was graded M4 or M3 for the biceps muscle in 85.4% of patients, for the deltoid muscle in 82.9% of patients, and for the upper parts of pectoral major in 92.7% of patients. The functional recovery of shoulder abduction in the patients with the additional suprascapular nerve neurotization was remarkably improved. Conclusions: The modified prespinal route could significantly reduced the length of nerve graft in the contralateral C7 nerve root transfer to the injured upper trunk in brachial plexus root avulsion injury, and it may improve the functional outcomes, which deserves further investigations. © 2011 Wiley Periodicals, Inc. Microsurgery, 2012.     

Mobilization of the phrenic nerve in the thoracic cavity by video-assisted thoracic surgery

Background: The use of video-assisted thoracic surgery (VATS) techniques to mobilize the phrenic nerve in the thoracic cavity for neurotization after brachial plexus injury was studied. Methods: From August 1999 to January 2000, 10 men and 1 woman with brachial plexus injury (left side in 5 and right side in 6) joined the study group. Their ages ranged from 20 to 38 years (average, 28 years). Supine after general anesthesia, all the patients had double-lumen trachea cannulas to guarantee complete lung collapse on the operative side. Three port incisions were made to allow introduction of the following: a 10-mm Stryker endoscope through the sixth intercostal space 2 cm medial to the anterior axillary line, one instrument for manipulation in the anterior axillary line of the third intercostal space, and another in the second intercostal space about 2 cm lateral to the parasternal line. The nerve was mobilized with two common long Mixter clamps and some endoscopic instruments by blunt and sharp dissection. Results: All patients were managed successfully without severe complications. The mean additional length of phrenic nerves by this technique was 16 cm. Conclusions: Mobilization of the phrenic nerve by VATS is a safe and minimally invasive method for elongating the nerve for neurotization after brachial plexus injury.     

Axillary nerve neurotization with the anterior deltopectoral approach in brachial plexus injuries

Combined neurotization of both axillary and suprascapular nerves in shoulder reanimation has been widely accepted in brachial plexus injuries, and the functional outcome is much superior to single nerve transfer. This study describes the surgical anatomy for axillary nerve relative to the available donor nerves and emphasize the salient technical aspects of anterior deltopectoral approach in brachial plexus injuries. Fifteen patients with brachial plexus injury who had axillary nerve neurotizations were evaluated. Five patients had complete avulsion, 9 patients had C5, six patients had brachial plexus injury pattern, and one patient had combined axillary and suprascapular nerve injury. The long head of triceps branch was the donor in C5,6 injuries; nerve to brachialis in combined nerve injury and intercostals for C5‐T1 avulsion injuries. All these donors were identified through the anterior approach, and the nerve transfer was done. The recovery of deltoid was found excellent (M5) in C5,6 brachial plexus injuries with an average of 134.4° abduction at follow up of average 34.6 months. The shoulder recovery was good with 130° abduction in a case of combined axillary and suprascapular nerve injury. The deltoid recovery was good (M3) in C5‐T1 avulsion injuries patients with an average of 64° shoulder abduction at follow up of 35 months. We believe that anterior approach is simple and easy for all axillary nerve transfers in brachial plexus injuries. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.     

Outcomes of surgical treatment of brachial plexus injuries using nerve grafting and nerve transfers

Between 1993 and 1998, 32 male patients with brachial plexus injuries were surgically treated. Eighteen interfascicular grafting and 71 extraplexal neurotization procedures were performed separately or in combination. Donor nerves were the intercostals, spinal accessory, phrenic, contralateral C7, and cervical plexus, in order of frequency. Patients were followed for a minimum of 24 (average, 35) months. Biceps function was best following grafting the musculocutaneous nerve itself, or neurotization with the phrenic nerve (100 percent grade 4), followed by neurotization with the intercostals (89.5 percent grade 3 or more) and last, grafting the C5 root or upper trunk (grade 3 in one of three patients). Phrenic to suprascapular neurotization produced the best results of shoulder abduction (40 to 90 degrees), followed by combined neurotization of the spinal accessory to suprascapular and phrenic to axillary (20 to 90 degrees). Sensory recovery over the lateral forearm and palm varied from S2 to S3+, according to the method of reconstruction.     

Quantitation of and superficial surgical landmarks for the anterior interosseous nerve

OBJECT: There are scant data regarding the anterior interosseous nerve (AIN) in the neurosurgical literature. In the current study the authors attempt to provide easily identifiable superficial osseous landmarks for the identification of the AIN. METHODS: The AIN in 20 upper extremities obtained in adult cadaveric specimens was dissected and quantified. Measurements were obtained between the nerve and surrounding superficial osseous landmarks. The AIN originated from the median nerve at mean distances of 5.4 cm distal to the medial epicondyle of the humerus and 21 cm proximal to the ulnar styloid process. The distance from the origin of the AIN to its branch leading to the flexor pollicis longus muscle and to the point it travels deep to the pronator quadratus (PQ) muscle measured a mean 4 and 14.4 cm, respectively. The mean distance from the AIN branch leading to the flexor pollicis longus muscle to the proximal PQ muscle was 12.1 cm, and the mean distance between this branch and the ulnar styloid process was 7.2 cm. The mean diameter of the AIN was 1.6 mm at the midforearm. CONCLUSIONS: Additional landmarks for identification of the AIN can aid the neurosurgeon in more precisely isolating this nerve and avoiding complications. Furthermore, after quantitation of this nerve, the AIN branches can be easily used for neurotization of the median and ulnar nerves, and with the aid of a transinterosseous membrane tunneling technique, passed to the posterior interosseous nerve.     

Repair of brachial plexus lesions by end-to-side side-to-side grafting neurorrhaphy: experience based on 11 cases

Eleven brachial plexus lesions were repaired using end-to-side side-to-side grafting neurorrhaphy in root ruptures, in phrenic and spinal accessory nerve neurotizations, in contralateral C7 neurotization, and in neurotization using intact interplexus roots or cords. The main aim was to approximate donor and recipient nerves and promote regeneration through them. Another indication was to augment the recipient nerve, when it had been neurotized or grafted to donors of dubious integrity, when it was not completely denervated, when it had been neurotized to a nerve with a suboptimal number of fibers, when it had been neurotized to distant donors delaying its regeneration, and when it had been neurotized to a donor supplying many recipients. In interplexus neurotization, the main indication was to preserve the integrity of the interplexus donors, as they were not sacrificeable. The principles of end-to-side neurorrhaphy were followed. The epineurium was removed. Axonal sprouting was induced by longitudinally slitting and partially transecting the donor and recipient nerves, by increasing the contact area between both of them and the nerve grafts, and by embedding the grafts into the split predegenerated injured nerve segments. Agonistic donors were used for root ruptures and for phrenic and spinal accessory neurotization, but not for contralateral C7 or interplexus neurotization. Single-donor single-recipient neurotization was successfully followed in phrenic neurotization of the suprascapular (3 cases) and axillary (1 case) nerves, spinal accessory neurotization of the suprascapular nerve (1 case), and dorsal part of contralateral C7 neurotization of the axillary nerve (2 cases). Apart from this, recipient augmentation necessitated many donor to single-recipient neurotizations. This was successfully performed using phrenic-interplexus root to suprascapular transfers (2 cases), phrenic-contralateral C7 to suprascapular transfer (1 case), and spinal accessory-interplexus root to musculocutaneous transfer (1 case). Both recipient augmentation and increasing the contact area between grafts and recipients necessitated single or multiple donor to many recipient neurotizations. This was applied in root ruptures (3 cases), with results comparable to those obtained in classical nerve-grafting techniques. It was also applied in ventral C7 transfer to the lateral or medial cords (3 cases) with functional recovery occurring in the biceps and pronator teres muscles, but not in dorsal C7 transfer to the axillary and radial nerves (3 cases) with functional recovery occurring in the deltoid and triceps muscles, and in whole C7 transfer to C5, 6, 7, 8T1 roots with functional recovery occurring in the deltoid (M4), biceps (M4), pronator teres (M4), and triceps (M3) (3 cases), and less so in the flexor carpi ulnaris and FDP (M3) (1 case) and the extensor digitorum longus (M3) (1 case). Contralateral C7 transfer to the lateral and posterior cords (4 cases) was followed by cocontractions that took 1 year to improve and that involved the rotator cuff, deltoid, biceps, and pronator teres (all agonists). Functional recovery in the triceps muscle was less than in the above muscles. Contralateral C7 transfer to C5-7 (1 case) was followed by cocontractions that took 1 year to resolve and that occurred between the deltoid, biceps, and flexor digitorum profundus. Interplexus root neurotization was done only in conjunction with other neurotization techniques, and so its role is difficult to judge. Though the same applies to regenerated lateral cord transfer to the posterior cord (2 cases), the successful results obtained from medial cord neurotization to the axillary, musculocutaneous, and radial nerves (1 case), and from ulnar and median nerve neurotization to the radial nerve (1 case), show that neurotization at the interplexus cord level may play a role in brachial plexus regeneration and may even be used to neurotize nerves and muscles distal to the elbow. The timing of repair was within 6 months after injury, except for 2 cases. In the first case, contralateral C7 transfer was successfully performed more than 1 year after injury. The second case was an obstetric palsy operated upon at age 8. Deterioration in motor power of the donor muscles that improved in 6 months was observed in 2 cases of interplexus neurotization at the cord level, because of looping the sural nerve grafts tightly around the donor nerves. Deterioration in donor-muscle motor power as a consequence of end-to-side neurorrhaphy was noted in the obstetric palsy case, when the flexor carpi radialis (donor) became grade 3 instead of grade 4. This was associated with cocontractions between it and the extensors. It took nearly 1 year to improve.     

Surgical anatomy for direct hypoglossal-facial nerve side-to-end "anastomosis".

OBJECT: In this study the authors investigated the histomorphometric background and microsurgical anatomy associated with surgically created direct hypoglossal-facial nerve side-to-end communication or nerve "anastomosis." METHODS: Histomorphometric analyses of the facial and hypoglossal nerves were performed using 24 cadaveric specimens and three surgically obtained specimens of severed facial nerve. Both the hypoglossal nerve at the level of the atlas and the facial nerve just distal to the external genu were monofascicular. The number of myelinated axons in the facial nerve (7228 +/- 950) was 73.2% of those in the normal hypoglossal nerve (9778 +/- 1516). Myelinated fibers in injured facial nerves were remarkably decreased in number. The cross-sectioned area of the normal facial nerve (0.948 mm2) accounted for 61.5% of the area of the hypoglossal nerve (1.541 mm2), whereas that of the injured facial nerve (0.66 mm2) was less than 50% of the area of the hypoglossal nerve. Surgical dissection and morphometric measurements were performed using 18 sides of 11 adult cadaver heads. The length of the facial nerve from the pes anserinus to the external genu ranged from 22 to 42 mm (mean 30.5 +/- 4.4 mm). The distance from the pes anserinus to the nearest point on the hypoglossal nerve ranged from 14 to 22 mm (mean 17.3 +/- 2.5 mm). The former was always longer than the latter; the excess ranged from 6 to 20 mm (mean 13.1 +/- 3.4 mm). Surgical anatomy and procedures used to accomplish the nerve connection are described. CONCLUSIONS: The size of a half-cut end of the hypoglossal nerve matches a cut end of the injured facial nerve very well. By using the technique described, a length of facial nerve sufficient to achieve a tensionless communication can consistently be obtained.     

Femoral branch to obturator nerve transfer for restoration of thigh adduction following iatrogenic injury

Obturator nerve injury is a rare complication of pelvic surgery. A variety of management strategies have been reported, with conservative measures being the preferred treatment in most cases. While nerve transfer has become more commonly used for restoring brachial plexus injuries, it has rarely been applied to the lower extremities. To the authors' knowledge, this is the first report of an obturator nerve neurotization. A patient presented 7 months after an iatrogenic right obturator nerve palsy due to pelvic surgery for gynecological malignancy. She underwent a femoral branch to obturator nerve transfer to restore right thigh adduction. Ten months after the neurotization procedure, there was electromyographic evidence of almost complete obturator nerve reinnervation. At 1 year postoperatively, the patient had regained full muscle strength on thigh adduction and a normal gait. Nerve transfer could therefore be a good option in patients with obturator nerve injury whose symptoms fail to respond to conservative medical therapy.     

Initial report on the limited value of hypoglossal nerve transfer to treat brachial plexus root avulsions.

OBJECT: Hypoglossal nerve (12th cranial nerve) transfer was performed to treat the sequelae of brachial plexus root avulsion in 12 adults and two infants, and the patients were followed to assess the effectiveness of the surgery. METHODS: The 12th cranial nerve was transected at the base of the tongue, and a sural nerve graft was used to bridge the gap between the donor (12th) and recipient nerves: C-5 spinal, axillary, suprascapular, or musculocutaneous nerve. The mean graft length in adult patients was 15.75 +/- 5.5 cm (+/- standard deviation, median 14.5 cm) and in the two infants the graft lengths were 7 and 8 cm, respectively. After a mean postoperative interval of 1138 +/- 254 days, electromyographic examination of the target muscles showed tongue movement-related activity in all patients. Muscle force strength measured according to the Medical Research Council's guidelines, was Grade 3 or higher in 21% of patients. Contraction, however, could only be attained by tongue movements, and volitional control was not achieved. CONCLUSIONS: Although recovery of muscle strength was obtained by 12th cranial nerve transfer, the functional gain remained virtually nonexistent because central control was missing.     

肋间神经移位肩胛上神经的解剖学研究

目的探讨第3～6肋间神经移位肩胛上神经重建肩关节外展功能的可行性。方法取15具30侧成人躯干标本,解剖测量第3～6肋间神经自腋中线至锁骨中线可切取长度以及自腋中线至锁骨中点(拟定神经吻合点)的移位距离,并进行统计学比较。结果 30侧标本中,第3、4肋间神经均可切取自腋中线至锁骨中线范围内的全段神经,且可切取长度均较移位距离长(P<0.01)。6侧第5肋间神经及16侧第6肋间神经在未到达锁骨中线时被肋软骨覆盖,其中第5肋间神经可切取长度与移位距离相似(P>0.01),第6肋间神经可切取长度较移位距离短(P<0.01)。肩胛上神经通过游离切断,可翻转至锁骨中点下方2 cm以上。第5肋间神经切取长度与肩胛上神经翻转长度(2 cm)之和,可超过移位距离(P<0.01),但第6肋间神经总长度仍较移位距离短(P<0.01)。结论第3～5肋间神经可直接移位肩胛上神经重建肩关节外展功能,而第6肋间神经需增加游离切取长度范围或采用神经移植修复。     

Surgical relationship of the medial pectoral nerve to the musculocutaneous nerve: a cadaveric study

OBJECTIVE: For purposes of neurotization of the musculocutaneous nerve (MCN) with the medial pectoral nerve (MPN) after upper trunk brachial plexus injuries, the anatomic relationship between these two nerves was defined in a cadaveric model. METHODS: Thirty-five brachial plexuses in 18 adult cadavers were dissected. The distance between the origin of the MPN from the medial cord to the origin of the MCN from the lateral cord was measured. The length, diameter, branching, and location of the MPN were recorded. The diameter of the proximal MCN was recorded. RESULTS: Thirty-seven percent of the MPNs, when detached from the pectoralis muscles, were too short to reach the proximal MCN by a mean distance of 15 mm. The MPN pierced the pectoralis minor muscle in 80% of the dissections. The cross sectional area of the MCN was always larger than the cross sectional area of the MPN by an average factor of 2.5. CONCLUSION: When planning to use the MPN for neurotization of the MCN, one should be prepared to harvest an interposition graft, because over one-third of MPNs may not have enough length to reach the MCN in a tension-free manner. Diameter mismatch occurs predictably between the distal MPN and the proximal MCN.     

Reinnervation of extraocular muscles by facial-to-oculomotor nerve anastomosis in rats: anatomic nuclear changes

OBJECTIVE: Oculomotor nerve palsy greatly impairs the patient's daily life. After oculomotor nerve injury, when the central nerve stump is not available, neurotization of the distal nerve stump with a donor nerve may be performed. Here, we present an experimental anatomic study in rats related to the motor nuclear organization after facial-to-oculomotor nerve anastomosis. METHODS: In adult rats, the right oculomotor nerve was transected at the skull base. Then, the ipsilateral facial nerve was exposed at the stylomastoid foramen and connected side-to-end to one extremity of a peroneal nerve autograft. The other extremity of the nerve autograft was connected end-to-end to the distal stump of the transected oculomotor nerve. Twelve weeks later, axonal regeneration in the autograft and brainstem somatotopic representation of the reinnervated extraocular muscles were investigated by use of histological and retrograde axonal tracing techniques. RESULTS: The autograft was reinnervated by a large number of small axons, 1 to 5 microm in diameter. After tracer injection into the superior rectus and medial rectus muscles, retrogradely labeled neurons were seen not only in the ipsilateral facial nucleus (16%) but also in the contralateral nucleus (8%). Labeled neurons were also seen in the ipsilateral abducens (12%), motor trigeminus (7%), trochlear (23%), and contralateral trochlear (34%) nuclei. In normal rats, the extraocular muscles are innervated by unilateral-ipsilateral brainstem motor nuclei, except for the superior rectus and superior oblique muscles, which are innervated by bilateral, primarily contralateral, nuclei. CONCLUSION: The central rearrangement of the extraocular muscle nuclei after facial-to-oculomotor nerve anastomosis represents an original example of plasticity. Functional studies are needed to demonstrate whether this procedure might serve to restore some degree of eye motility.