The sensory restoration in radial nerve injury using the first branch of dorsal ulnar cutaneous nerve--a cadaveric study for the feasibility of procedure and case demonstration

OBJECTIVE

To demonstrate the new sensory restoration technique in radial nerve injury using the first branch of dorsal ulnar cutaneous nerve as the donor sensory nerve.

MATERIAL AND METHOD

Forty formalin-preserved cadavers (18 males and 22 females) were used as the subjects of the present study. The localization of the origin of first branch of dorsal ulnar cutaneous nerve was performed. The measurement was done to determine the origin of this nerve in relation to the tip of ulnar styloid. The simulated transfer was done. The length of the superficial radial nerve that had to be cut was determined. The measurement was done by two observers to determine the reliability of measurement.

RESULTS

The mean horizontal distance (X) to the origin of first branch of dorsal ulnar cutaneous nerve measured from the tip of ulnar styloid on the right and left side were 5.22 mm and 6.51 mm respectively. The mean vertical distance (Y) to the origin of first branch of dorsal ulnar cutaneous nerve measured from the tip of ulnar styloid on the right and left side were -7.72 mm and -4.37 mm respectively. The mean length of superficial radial nerve that had to be cut to allow tension free anastomosis, measured from the tip of radial styloid on the right and left side were 68.21 mm and 65.92 mm respectively. The estimated average size of the transferred branch of ulnar cutaneous nerve was about 70% of the size of superficial radial nerve.

CONCLUSION

The sensory restoration in radial nerve injury using sensory nerve transfer from the first branch of dorsal ulnar cutaneous nerve was technically feasible regarding to the comparable size between two nerves and anatomic consistency of the first branch of dorsal ulnar cutaneous nerve.

Variation in nerve autograft length increases fibre misdirection and decreases pruning effectiveness. An experimental study in the rat median nerve

OBJECTIVES

In the clinical set, autologus nerve grafts are the current option for reconstruction of nerve tissue losses. The length of the nerve graft has been suggested to affect outcomes. Experiments were performed in the rat in order to test this assumption and to detect a possible mechanism to explain differences in recovery.

METHODS

The rat median nerve was repaired by ulnar nerve grafts of different lengths. Rats were evaluated for 12 months by behavioural assessment and histological studies, including ATPase myofibrillary histochemistry and retrograde neuronal labelling.

RESULTS

It was demonstrated that graft length interferes in behavioural functional recovery that here correlates to muscle weight recovery. Short nerve grafts recovered faster and better. Reinnervation was not specific either at the trunk level or in the muscle itself. The normal mosaic pattern of Type I muscle fibres was never restored and their number remained largely augmented. An increment in the number of motor fibres was observed after the nerve grafting in a predominantly sensory branch in all groups. This increment was more pronounced in the long graft group. In the postoperative period, about a 20% reduction in the number of misdirected motor fibres occurred in the short nerve graft group only.

CONCLUSION

Variation in the length of nerve grafts interferes in behavioural recovery and increases motor fibres misdirection. Early recovery onset was related to a better outcome, which occurs in the short graft group.

Combined nerve transfers for repair of the upper brachial plexus injuries through a posterior approach

The upper brachial plexus injury leads to paralysis of muscles innervated by C5 and C6 nerve roots. In this report, we present our experience on the use of the combined nerve transfers for reconstruction of the upper brachial plexus injury. Nine male patients with the upper brachial plexus injury were treated with combined nerve transfers. The time interval between injury and surgery ranged from 3 to 11 months (average, 7 months). The combined nerve transfers include fascicles of the ulnar nerve and/or the median nerve transfer to the biceps and/or the brachialis motor branch, and the spinal accessory nerve (SAN) to the suprascapular nerve (SSN) and triceps branches to the axillary nerve through a posterior approach. At an average of 33 months of follow-up, all patients recovered the full range of the elbow flexion. Six out of nine patients were able to perform the normal range of shoulder abduction with the strength degraded to M3 or M4. These results showed that the technique of the combined nerve transfers, specifically the SAN to the SSN and triceps branches to the axillary nerve through a posterior approach, may be a valuable alternative in the repair of the upper brachial plexus injury. Further evaluations of this technique are necessary.

[Reconstruction of thumb opposition function by transferring extensor carpi ulnaris and extensor pollicis brevis muscle tendons]

OBJECTIVE

To evaluate the results of thumb opposition function by transferring the extensor carpi ulnaris and the extensor pollicis brevis muscle tendons.

METHODS

Between March 2006 and August 2009, 35 patients with dysfunction of thumb opposition were treated and the thumb opposition function was reconstructed by transferring the extensor carpi ulnaris and the extensor pollicis brevis muscle tendons. There were 25 males and 10 females with an average age of 33.5 years (range, 20-53 years); 20 had median nerve injury in the wrist and 15 had median nerve injury with ulnar nerve injury. The causes were sharp instrument injury in 24 cases, blunt injury in 9 cases, and hot crush injury in 2 cases. Six cases complicated by shaft fractures of radius and ulna. All the patients underwent an operation of nerve repair at 1 to 3 hours after injury (mean, 2 hours). The time from injury to reconstructing operation was 6-14 months (mean, 7.5 months). Two cases was able to abduct thumb slightly, the others had no functions of thumb abduct and thumb opposition.

RESULTS

All the wounds gained the primary healing. The patients were followed up 12-18 months (mean, 14 months). The wrist joint angle and thumb dorsal extension were satisfactory. Thumb abduct and thumb opposition function returned to normal in 20 patients with simple median nerve injury; in 15 patients with median nerve injury and ulnar nerve injury, thumb abduct and thumb opposition function returned to normal in 15 and 13, respectively. According to ZHAO Shuqiang's standard, the results of thumb opposition function were normal in all patients at 12 months after operation.

CONCLUSION

It is a convenient and efficient procedure to reconstruct thumb opposition function by transferring the extensor carpi ulnaris and the extensor pollicis brevis muscle tendons.

Results of c5 root grafting to the musculocutaneous nerve using pedicled, vascularized ulnar nerve grafts

PURPOSE

Vascularized nerve grafts are indicated for the repair of large nerve defects. In brachial plexus injuries, the poor prognosis for functional hand reconstruction when the lower roots are avulsed makes the ulnar nerve a potential donor for vascularized nerve grafts. We report on the results we obtained with reconstruction of elbow flexion using long pedicled ulnar nerve grafts that connected the C5 root to the musculocutaneous nerve.

METHODS

We prospectively studied 8 young adults with complete brachial plexus palsy with avulsion of the lower roots, who had surgical repair an average of 4.6 months after trauma. Pedicled ulnar nerve grafts, averaging 30 cm long, connected the C5 root to the musculocutaneous nerve. In order to rescue misdirected axons that could have regenerated into the cutaneous branch of the musculocutaneous nerve, we transferred this branch to the motor branch of the extensor carpi radialis brevis muscle. Outcomes for all 8 patients were assessed an average of 26.7 months after surgery, focusing on recovery of muscle strength, categorized using the Medical Research Council scale.

RESULTS

None of the patients recovered elbow flexion or wrist extension greater than M2.

CONCLUSIONS

In brachial plexus injuries, reconstruction of elbow flexion using a long, pedicled, vascularized nerve graft produces unsatisfactory results.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Sensory recovery after forearm median and ulnar nerve grafting

BACKGROUND

Median and ulnar nerve injuries are common, whether isolated or combined injury of both nerve. A nerve graft, if performed in a tensionless manner, has been shown to generally have better results than an end-to-end approximation performed under tension.

OBJECTIVE

The aim of this study is to analyze the long-term results of sensory recovery after secondary reconstruction median and ulnar nerve by autograft in patients who were treated on Clinic for Plastic and Reconstructive Surgery in the period from January 1st 1993 to December 31st 2005. We analyzed the influence of the patients age, level of injury, the size of the graft and the period between the injury and operation on the late results.

PATIENTS AND METHODS

Evaluation was performed in 55 patients with adequate follow-up. The mean follow-up period was 3.9 years. Reconstructions were applied on the median nerve in 31 patients and ulnar nerve in 24 patients. Criteria for inclusion in the study was median and ulnar nerve grafting in the forearm region. Patients were divided by age in two groups, below 25 and over 25 years, by injury level in the distal and proximal forearm injuries, by the length of autograft up to 5 cm and other group with graft length over 5 cm, by the period between injury and operation in group with denervation time up to 6 months and the group with denervation time over 6 months. Rating of sensibility was presented on the Highet Scale as modified by Dellon and more precise rating of sensibility was presented by Moberg's rating scale of sensibility. Calculation of frequencies and percentual values was performed for all included variables. For establishment of differences between the frequencies the /2-test was used (Chi square test) at the level of statistical importance (p < 0.05) with contingency tables.

RESULTS

We analyzed the results of reconstruction of median and ulnar nerves with respect to factors affecting functionally the result of operation, which are age, injury level, graft length and denervation time. We had 31 patients with median nerve grafting and we achieved sensory recovery S4 in 3 (10%) patients, S3+ in 9 (29%) patients, S3 in 8 (25.5%) patients, 52 in 9 (29%) patients and S2 in 2 (6.5%) patients. We had 24 patients with ulnar nerve grafting and we achieved S4 sensory recovery in 2 (8.5%) patients, S3+ in 6 (25%) patients, 53 in 5 (21%) patients, S2 in 10 (41%) patients and S2 in 1 (4%) patient. There was not significant difference in sensory recovery of median and ulnar nerve (chi-square = 1.00; df = 4; p = 0.909). There was not statistically significant difference by age and level of injury. The results were significantly better in patients with short grafts than in long ones (chi-square = 12.6; df = 4; p = 0.014) and in patients who had undergone surgical repair within 6 months (chi-square = 10; 2 df = 4; p = 0.038).

CONCLUSION

There was not significant difference in sensory recovery of median and ulnar nerves. The graft length and denervation time significantly influenced the functional outcome in sensory recovery. Mechanism of injury impacted on the results. Two point discrimination testing using a paperclip is a cheap, easily and quickly performed reproducible test of tactile gnosis, and should be included in nerve assessment protocols. We recommended using Moberg's rating scale for further research.

Nerve Bypass Grafting for the Treatment of Neuroma-in-Continuity: An Experimental Study on the Rat

The treatment of neuroma-in-continuity is controversial. To bypass neuroma-in-continuity with a nerve graft using end-to-side neurorrhaphy is considered to be theoretically a good option. To test this therapeutic modality, we performed a nerve bypass graft in a neuroma-in-continuity rat model. An obstructive neuroma-in-continuity was created in a transected peroneal nerve by interposition using the aponeurosis of the spinal muscles. In the experimental animals, (1) immediate, (2) 3-week delayed, or (3) no ulnar nerve bypass graft was performed. The peroneal functional index (PFI), conduction velocity, tibialis anterior muscle weight, and histomorphometric analyses were performed and compared with control (simply cut and repair) animals. On postoperative day 70, the recoveries of the PFI values, conduction velocity, and tibialis anterior muscle weight in the bypassed animals showed no significant differences as compared with the control animals, and the extent of these recoveries in the bypassed animals were significantly superior to those in the no-graft animals. In the histomorphometric analysis, the mean percent nerve in the bypassed animals was significantly larger than that in the no-graft animals. In conclusion, this technique may be a good alternative to the current therapeutic techniques for neuroma-in-continuity when there is a significant retained function.

Use of cold-preserved allografts seeded with autologous Schwann cells in the treatment of a long-gap peripheral nerve injury

BACKGROUND

Limitations in autogenous tissue have inspired the study of alternative materials for repair of complex peripheral nerve injuries. Cadaveric allografts are one potential reconstructive material, but their use requires systemic immunosuppression. Cold preservation (> or =7 weeks) renders allografts devoid of antigens, but these acellular substrates generally fail in supporting regeneration beyond 3 cm. In this study, the authors evaluated the reconstruction of extensive nonhuman primate peripheral nerve defects using 7-week cold-preserved allografts repopulated with cultured autologous Schwann cells.

METHODS

Ten outbred Macaca fascicularis primates were paired based on maximal genetic disparity as measured by similarity index assay. A total of 14 ulnar nerve defects measuring 6 cm were successfully reconstructed using autografts (n = 5), fresh allografts (n = 2), cold-preserved allografts (n = 3), or cold-preserved allografts seeded with autogenous Schwann cells (n = 4). Recipient immunoreactivity was evaluated by means of enzyme-linked immunosorbent spot assay, and nerves were harvested at 6 months for histologic and histomorphometric analysis.

RESULTS

Cytokine production in response to cold-preserved allografts and cold-preserved allografts seeded with autologous Schwann cells was similar to that observed for autografts. Schwann cell-repopulated cold-preserved grafts demonstrated significantly enhanced fiber counts, nerve density, and percentage nerve (p < 0.05) compared with unseeded cold-preserved grafts at 6 months after reconstruction.

CONCLUSIONS

Cold-preserved allografts seeded with autologous Schwann cells were well-tolerated in unrelated recipients and supported significant regeneration across 6-cm peripheral nerve defects. Use of cold-preserved allogeneic nerve tissue supplemented with autogenous Schwann cells poses a potentially safe and effective alternative to the use of autologous tissue in the reconstruction of extensive nerve injuries.

The Rho-Associated Kinase Inhibitor Fasudil Hydrochloride Enhances Neural Regeneration after Axotomy in the Peripheral Nervous System

BACKGROUND

The Rho family of small GTPases is responsible for various processes involving actin cytoskeleton in eukaryotic cells, including neurite outgrowth. Several substances found at the peripheral nerve injury site were shown to activate one member of this family, Rho. The activation of Rho leads to neurite outgrowth inhibition and the development of posttraumatic neuropathic pain. The authors used the clinically tested Rho-associated kinase inhibitor fasudil hydrochloride to enhance the functional recovery of the peripheral nerve in the rat.

METHODS

In the peroneal nerve interpositional graft model, the authors administered fasudil (experimental groups) or saline (control groups) (1) intraperitoneally and (2) directly into the graft by microinjection (n = 6 animals per experimental condition). Neural recovery was assessed during postoperative follow-up lasting 80 days by peroneal functional index, electrophysiologic, and histomorphometric analyses.

RESULTS

The peroneal functional index returned to values not significantly different from preoperative values on days 55 (fasudil injected into the graft) and 60 (fasudil injected intraperitoneally) in the experimental groups. In the control groups, this took 70 (saline injected intraperitoneally) and 75 days (saline injected into the graft). These results are supported by electrophysiologic and histomorphologic assessments.

CONCLUSIONS

The authors determined that fasudil hydrochloride was capable of accelerating the functional regeneration after peripheral nerve axotomy, which is consistent with the results of reports about Rho cascade disruption in the central nervous system. Because fasudil hydrochloride is a clinically tested drug, it could be used to enhance neural regeneration in human patients as well.

Long nerve gaps limit the regenerative potential of bioartificial nerve conduits filled with Schwann cells

PURPOSE

Recently we successfully used a conduit of epsilon-caprolactone-co-trimethylene carbonate filled with Schwann cells (SC) across a 20 mm gap in a rat median nerve. In this study we applied the tubes with SC across a 40 mm gap in order to analyse the regenerative potential of the tubes in long nerve defects.

METHODS

To augment the nerve defect a cross-chest procedure was used and the tubes were implanted with injected isogeneic SCs inside (group 3). Both ulnar nerves were used for a 40 mm autograft (group 2). For control group non-operated animals were used (group 1). The grasping test, histology (S-100, PAM), electrophysiology, and the muscle weight were used to assess regeneration.

RESULTS

After 12 months, grasping was seen only in three animals of group 3 (3.6 g [95% CI: 0 to 7.6 g]). However, in group 2 all rats had a partial functional regeneration (42.8 g [95% CI: 39.1 to 46.6 g]). The grasping force of the non-operated animals (group 1) was 240.9 g [95% CI: 237.2 to 244.7 g] at the time. Histology from group 3 confirmed an irregular arrangement of fibres in contrast to more organized structures in group 2. Electrophysiology in group 3 displayed potentials only in the three animals with functional regeneration. In group 2 all animals exhibited potentials. A significant decrease of muscle weight was observed in groups 2 and 3, most prominent in the latter.

CONCLUSION

Regeneration was not successful across the 40 mm gap using the applied tube in combination with SC. For future experiments further consideration should be taken in optimizing the cellular and material components that are critical for a successful application to overcome very large nerve gaps.

Cross-chest median nerve transfer: A new model for the evaluation of nerve regeneration across a 40mm gap in the rat

A new animal model for the study of nerve regeneration in rats across a 40 mm gap between both median nerves is described. For autologous grafting, the ulnar nerves were dissected and sutured together. From the left median nerve, they were transplanted across the chest to the right median nerve. Animals having undergone this operation were observed for 12 months and periodically assessed using the grasping test and measurements of body-weight. For histological analysis rats were sacrificed after this period and axon counts were determined at the suture points of operated animals and in the median nerve of non-operated animals. Functional recovery could be seen, although partially, beginning as early as the fifth postoperative month, as demonstrated by the grasping test. Quantification of the number of axons demonstrated axonal regeneration across all three coaptation points. This model provides a new approach for analysis of long distance peripheral nerve regeneration without impairment of behaviour.

Vascularized ulnar nerve graft

The purpose of this article is to describe the indications, anatomy, and harvesting technique of vascularized ulnar nerve graft based on the superior ulnar collateral artery (SUCA) for reconstruction of upper extremity function. The ulnar nerve has an extrinsic blood supply consisting of multiple dominant systems: the SUCA, the inferior ulnar collateral artery, the posterior ulnar recurrent artery, and the ulnar artery. The entire length of the ulnar nerve can survive based on the SUCA and its venae comitantes. The vascularized ulnar nerve graft is used when there is a hopeless prognosis for ulnar nerve repair. This technique may be selected if there is a definite evidence of preganglionic injuries of the C8 and T1 roots in brachial plexus injuries. This technique can be recommended for reconstruction of a large defect of the median or radial nerves in selected cases, such as upper arm replantation.

Results of reinnervation of the biceps and brachialis muscles with a double fascicular transfer for elbow flexion

PURPOSE

To report the results of a surgical technique of nerve transfer to reinnervate the brachialis muscle and the biceps muscle to restore elbow flexion after brachial plexus injury.

METHODS

Retrospective review was performed on 6 patients who had direct nerve transfer of a single expendable motor fascicle from both the ulnar and median nerves directly to the biceps and brachialis branches of the musculocutaneous nerve. Assessment included degree of recovery of elbow flexion and ulnar and median nerve function including pinch and grip strengths.

RESULTS

Clinical evidence of reinnervation was noted at a mean of 5.5 months (SD, 1 mo; range, 3.5-7 mo) after surgery and the mean follow-up period was 20.5 months (SD, 11.2 mo, range, 13-43 mo). Mean recovery of elbow flexion was Medical Research Council grade 4+. Postoperative pinch and grip strengths were unchanged or better in all patients. No motor or sensory deficits related to the ulnar or median nerves were noted and all patients maintained good hand function. No patients required additional procedures to further improve elbow flexion strength.

CONCLUSIONS

Transfer of expendable motor fascicles from the ulnar and median nerves successfully can reinnervate the biceps and brachialis muscles for strong elbow flexion. The reinnervation of the brachialis muscle, the primary elbow flexor, as well as the biceps muscle provides an additional biomechanical advantage that accounts for the excellent elbow flexion strength obtained using this technique. Direct coaptation of the nerve fascicles was performed without the need for nerve grafts and there was no functional or sensory donor morbidity.

Vascularized ulnar nerve graft for reconstruction of a large defect of the median or radial nerves after severe trauma of the upper extremity

We report 3 cases of successful vascularized ulnar nerve graft for reconstructing a large median or radial nerve defect after severe trauma of the upper extremity.

Effects of Schwann cells and donor antigen on long-nerve allograft regeneration

Nerve allotransplantation has been used successfully in human subjects to restore function after traumatic nerve injury and avoid subsequent limb amputation. However, due to the morbidity associated with nonspecific immunosuppression, this reconstructive approach has been limited to patients with particularly severe nerve injuries. It would be desirable to broaden the indications for such procedures through development of less toxic antirejection therapies. A miniature swine model of nerve transplantation was used to investigate the effects of preoperative ultraviolet-B (UV-B)-irradiated donor alloantigen portal venous infusion and injection of cultured major histocompatibility complex (MHC)-matched Schwann cells into the nerve graft. The transplanted ulnar nerves were harvested at 20 weeks. Histomorphometry showed marked enhancement in nerve regeneration through allografts injected with Schwann cells. Serial mixed lymphocyte assays demonstrated suppression of the recipient immune response to the donor antigen after pretreatment, but no additional neuroregenerative effect of donor alloantigen pretreatment.

Oberlin's ulnar nerve transfer to the biceps motor nerve in obstetric brachial plexus palsy: indications, and good and bad results

We present 7 children with obstetric brachial plexus palsy treated by transferring two motor fascicles out of the ulnar nerve to the biceps nerve. Three were male, and 4 were female. The left-side brachial plexus was affected in 4 patients, and the right side in 3 patients. All children had vaginal delivery; two of them presented with shoulder dystocia. The average birth weight was 4300 g (range, 3620-5500 g). Average age at time of operation was 16 months (range, 11-24 months). The indication for the operation was absent active elbow flexion with active shoulder abduction against gravity in 4 cases, and no biceps function and bad shoulder function in 3 cases. Oberlin's ulnar nerve transfer was done in 4 cases without brachial plexus exploration in those children with good shoulder function, and exploration of the brachial plexus was performed in the other 3 cases with bad shoulder function. The average follow-up was 19 months (range, 13-30 months). Five children had biceps muscle >or=M(3) with active elbow flexion against gravity, and 2 children had biceps muscle <M(3). We recommend Oberlin's ulnar nerve transfer for upper-type obstetric brachial plexus palsy in 1). breech delivery with avulsion of C5 and C6 nerve roots,) late presentation with good recovery of shoulder function, and 3). neuroma-in-continuity of the upper trunk with intraoperative good nerve conduction for the shoulder muscles, the same as preoperative good shoulder function but with no biceps action.

Functional outcomes in young, active duty, military personnel after submuscular ulnar nerve transposition

PURPOSE

The purpose of this study was to report on the results of submuscular ulnar nerve transposition (SMUNT) for treatment of cubital tunnel syndrome in a young, active duty, military population.

METHODS

Twenty patients (20 extremities) were evaluated retrospectively a minimum of 12 months after surgery. Outcome analyses were performed using the Disability of the Arm, Shoulder, and Hand (DASH) questionnaire and the Bishop-Kleinman rating scales, physical examination, return-to-work analysis, evaluation of complication rate, and overall patient satisfaction.

RESULTS

At an average follow-up evaluation of 24 months (range, 12-38 mo), 19 patients had returned to full military active duty work status. The average duration of limited work capacity after surgery was 4.8 months (range, 3-7 mo). The DASH scores improved from an average of 32.5 points before surgery to 6.2 points after surgery. In 19 patients the functional outcome evaluated with the Bishop-Kleinman rating system was excellent. There were no poor outcomes using this rating score. Statistically significant improvements in both key pinch and grip strength were noted. Complications included one permanent and 2 transient neuropraxias of the medial antebrachial cutaneous nerve. Overall 19 of 20 patients were satisfied with the procedure and would have the surgery again if required.

CONCLUSIONS

Submuscular ulnar nerve transposition for cubital tunnel syndrome provides a reliable rate of return to full active duty work in military personnel with good patient satisfaction and minimal complications.

Significance of shoulder function in the reconstruction of prehension with double free-muscle transfer after complete paralysis of the brachial plexus

Reconstruction of shoulder stability and movement in cases with complete paralysis of the brachial plexus was performed to improve the outcomes for universal function of prehension after double free-muscle transfer (Doi's procedure). In cases in which the C5 or C6 nerve root was available as a donor, neurotization of the supra-scapular nerve was performed with a nerve graft. If the C5 or C6 nerve root was not available, then the contralateral C7 nerve root was chosen as the donor motor nerve and was transferred to the suprascapular nerve by using a vascularized ulnar nerve graft. Seven cases with ipsilateral C4, C5, or C6 nerve root transfer to the suprascapular nerve and one with contralateral C7 transfer were evaluated, and the functional outcomes for the range of shoulder motion were compared with those for patients who had undergone arthrodesis of the humeroscapular joint or had undergone no procedures for shoulder function reconstruction. The patients who underwent supra-scapular nerve repair demonstrated statistically significantly better ranges of motion for flexion and abduction of the shoulder, compared with the other two groups. Shoulder function is important for achieving prehensile function among patients with complete paralysis of brachial function, when they undergo double free-muscle transfer.

Early nerve repair after injury to the postganglionic plexus: an experimental study of sensory and motor neuronal survival in adult rats

The optimal time for brachial plexus nerve repair is debatable. In this study we examined whether early re-establishment of neurotrophic support from the periphery might reduce neuronal loss. In 14 adult rats, the C7 spinal nerve was transsected. All sensory cells of the dorsal root ganglion and spinal motor neurons projecting into the C7 nerve were labelled retrogradely. The proximal and distal portions of the C7 nerve were then reanastomosed by either primary repair or by a vascularised or conventional ulnar nerve graft. At 16 weeks postoperatively, the nerve repair had significantly reduced the loss of both sensory and motor C7 neurons. Most striking was that a 30% motor neuronal loss in the control was almost eliminated by early nerve repair. In the grafted animals, half of the surviving neurons had regenerated through the graft, with no difference between vascularised and conventional nerve grafts. These results suggest that early surgical intervention may promote neuronal survival and regeneration after injuries to the brachial plexus.

Transfer of one fascicle of ulnar nerve to functioning free gracilis muscle transplantation for elbow flexion

BACKGROUND

In brachial plexus injury, elbow flexion is the first priority in reconstruction. Neglected cases need functioning free muscle transplantation that requires the donor nerve to supply the transplanted muscle. The purpose of this study was to investigate the effects and results of transferring one fascicle of the ulnar nerve to the transplanted gracilis muscle.

METHODS

One woman and two men with neglected avulsions of the C5,C6 roots of the brachial plexus underwent free gracilis muscle transfer for elbow flexion. One fascicle of the ulnar nerve was used as the donor nerve.

RESULTS

The mean period of follow-up was 33.3 months. The average reinnervation time of gracilis muscle was 3.7 months. At the final examination, the mean strength of elbow flexion was 4.3 kgf. The grip strength, moving two-point discrimination and the strength of the wrist volar flexion on the affected side was not worse than before surgery in any patient at the last follow-up examination.

CONCLUSIONS

A fascicle of the ulnar nerve can be one of the most effective options for functioning free muscle transplantation for elbow flexion.

[Acellular nerve allograft by chemical extraction in humans]

OBJECTIVE

To develop a procedure by which Schwann cells and myelin in the peripheral nerve could be removed while the basal lamina tubes remained intact, and to obtain a thick and long acellular nerve allograft in humans.

METHODS

Four ulnar nerves 10.0 cm long and 4.0 - 5.0 mm in diameter were excised from a donated male body and cleaned from external debris. The nerves were treated with a solution of Triton X-100 and a solution of sodium deoxycholate at room temperature. After a final wash in water, the nerves were stored in phosphate-buffered saline (PBS, pH 7.2) at 4 degrees C. HE, luxol fast blue and fibrin staining were performed to visualize cells, myelin and basal membranes respectively and immunohistochemical staining was performed to visualize the presence of laminin, a Schwann cell lamina component, both in fresh and acellular nerve segments. To reveal overall structure better, methylene blue-fuchsin staining was performed in semithin section. The ultrastructure of acellular and fresh nerves were observed and photographed in a transmission electron microscope.

RESULTS

The acellular human ulnar nerve was white long cylinder with well elasticity and ductility. HE, myelin and fibrin staining revealed that cells, axons and myelin sheath were removed and basal membrane was preserved after extraction procedure. Staining for the presence of laminin showed that the Schwann cell basal lamina component were present in the nerves after chemical treatment. Methylene blue-fuchsin staining and transmission electron microscopy showed that the myelin sheaths were absent in the extracted nerve segments and empty basal lamina tubes remained in the endoneurium.

CONCLUSIONS

We developed an extracted procedure with the detergents of Triton X-100 and deoxycholate, by which cells, axons and myelin sheaths could be removed from a human ulnar nerve while the basal lamina tubes remain intact and a thick long acellular nerve allograft is obtained. The laminin, a Schwann cell basal lamina component, can be preserved in the acellular nerve.

Nerve transfer for treatment of brachial plexus injury: comparison study between the transfer of partial median and ulnar nerves and that of phrenic and spinal accessary nerves

OBJECTIVE

To compare the effect of using partial median and ulnar nerves for treatment of C(5-6) or C(5-7) avulsion of the brachial plexus with that of using phrenic and spinal accessary nerves.

METHODS

The patients were divided into 2 groups randomly according to different surgical procedures. Twelve cases were involved in the first group. The phrenic nerve was transferred to the musculocutaneous nerve or through a sural nerve graft, and the spinal accessary nerve was to the suprascapular nerve. Eleven cases were classified into the second group. A part of the fascicles of median nerve was transferred to be coapted with the motor fascicle of musculocutaneous nerve and a part of fascicles of ulnar nerve was transferred to the axillary nerve. The cases were followed up from 1 to 3 years and the clinical outcome was compared between the two groups.

RESULTS

There were 2 cases (16.6%) who got the recovery of M4 strength of biceps muscle in the first group but 7 cases (63.6%) in the second group, and the difference was statistically significant (P<0.025). However, it was not statistically different in the recovery of shoulder function between the two groups.

CONCLUSIONS

Partial median and ulnar nerve transfer, phrenic and spinal accessary nerve transfer were all effective for the reconstruction of elbow or shoulder function in brachial plexus injury, but the neurotization using a part of median nerve could obtain more powerful biceps muscle strength than that of phrenic nerve transfer procedure.

A part of the ulnar nerve as an alternative donor nerve for functioning free muscle transfer: a case report

A patient with no active elbow flexion because of poliomyelitis-like syndrome underwent functioning free muscle transfer for elbow flexion reconstruction in which a part of the ulnar nerve was used as a donor motor nerve. Fourteen months after surgery the patient had achieved 120 degrees of active elbow flexion against gravity without functional deficit of the donor ulnar nerve. A part of the ulnar nerve can be used as an alternative donor motor nerve for reconstruction of chronic C5-C6 (or C5-7) brachial plexus injury.

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.