A Rapid Protocol for Intraoperative Assessment of Peripheral Nerve Myelinated Axon Count and Its Application to Cross-Facial Nerve Grafting.

BACKGROUND: Donor nerve myelinated axon counts correlate with functional outcomes in reanimation procedures; however, there exists no reliable means for their intraoperative quantification. In this article, the authors report a novel protocol for rapid quantification of myelinated axons from frozen sections, and demonstrate its applicability to surgical practice. METHODS: The impact of various fixation and FluoroMyelin Red staining strategies on resolved myelin sheath morphology from cryosections of rat and rabbit femoral and sciatic nerves was assessed. A protocol comprising fresh cryosection and rapid staining was developed, and histomorphometric results were compared against conventional osmium-postfixed, resin-embedded, toluidine blue-stained sections of rat sciatic nerve. The rapid protocol was applied for intraoperative quantification of donor nerve myelinated axon count in a cross-facial nerve grafting procedure. RESULTS: Resolution of myelinated axon morphology suitable for counting was realized within 10 minutes of tissue harvest. Although mean myelinated axon diameter appeared larger using the rapid fresh-frozen as compared to conventional nerve processing techniques (mean ± SD; rapid, 9.25 ± 0.62 µm; conventional, 6.05 ± 0.71 µm; p < 0.001), no difference in axon counts was observed on high-power fields (rapid, 429.42 ± 49.32; conventional, 460.32 ± 69.96; p = 0.277). Whole nerve myelinated axon counts using the rapid protocol herein (8435.12 ± 1329.72) were similar to prior reports using conventional osmium processing of rat sciatic nerve. CONCLUSIONS: A rapid protocol for quantification of myelinated axon counts from peripheral nerves using widely available equipment and techniques has been described, rendering possible intraoperative assessment of donor nerve suitability for reanimation.

Use of bioabsorbable nerve conduits as an adjunct to brachial plexus neurorrhaphy.

PURPOSE: The use of bioabsorbable conduits in digital nerve repair has demonstrated increased efficacy compared to direct repair (for gaps ≤ 4mm) and nerve grafting (for gaps ≥ 8 mm) for sensory recovery in a level 1 human trial. Although nonhuman primate studies on mixed motor-sensory nerves have documented comparable efficacy of the bioabsorbable nerve conduits when compared to nerve repair or grafting, there is minimal human clinical data on motor recovery following bioabsorbable nerve conduit repair. This study investigates the outcomes of bioabsorbable nerve conduits in pure motor nerve reconstruction for adult traumatic brachial plexus injuries. METHODS: Over a 3-year period, 21 adult patients had 1 or more nerve-to-nerve transfers for traumatic brachial plexus palsy performed using the operative microscope. Ten nerve transfers were performed by advancing the nerve ends into a semi-permeable type I collagen conduit stabilized with 8-0 nylon sutures (conduit-assisted neurorrhaphy). Twenty-eight concurrent nerve transfers were performed using standard end-to-end neurorrhaphy and 8-0 or 9-0 nylon sutures. Clinical evaluation using the Medical Research Council grading system (MRC) was performed at 1 and 2 years postoperatively. Postoperative electromyographic studies were performed in 28 of 38 transfers at final follow-up. RESULTS: Thirty transfers (17 patients) were available for 2-year follow-up evaluation. All 10 transfers performed with nerve conduits demonstrated clinical recovery and electromyographic reinnervation at 2 years. Eighteen of 20 transfers performed without conduits demonstrated clinical recovery. CONCLUSIONS: Although no statistical difference in functional recovery was seen in nerve transfers performed with collagen nerve conduits or by traditional neurorrhaphy, this pilot series demonstrated clinical and electromyographic recovery in 10 of 10 motor nerve repairs performed using conduits. These findings warrant continued investigation into the efficacy of conduit-assisted repair for motor nerves, especially in regards to operative time, precision of repair, and speed of nerve recovery. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The Oberlin procedure for restoration of elbow flexion with the da Vinci robot: four cases.

UNLABELLED: Robotics allows up to 40× visual magnification and 10× magnification of the surgeon's movements, and eliminates physiologic tremors. These properties should allow the development of mini-invasive limb surgery, especially of the brachial plexus. The purpose of this work was to test the feasibility of the restoration of elbow flexion according to the technique of Oberlin using a da Vinci robot. The authors' series included four patients (average age, 31 years) presenting with elbow flexion paralysis. They were operated on 8 months after injury using a da Vinci S robot. In three patients, the open technique (technique 1) was used, and the mini-invasive approach (technique 2) was used for the last one. Strength of elbow flexion was measured. After 1-year follow-up, all of the patients had recovered elbow flexion. No sensory or motor deficit was found in the ulnar nerve territory. There was no difficulty with technique 1; technique 2, however, required a conversion to technique 1 because of difficulty visualizing the operative field. The results of the authors' series show the feasibility of the robot-assisted technique for the Oberlin procedure. The lack of sensory feedback was not an issue. The development of specific retractors and instruments should improve the mini-invasive technique. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Pediatric sural nerve harvest: a fully endoscopic technique.

OBJECTIVE: The sural nerve has long been a favorite for peripheral nerve repair. Traditional "stocking seam" and "stair-step" harvest techniques both have serious drawbacks, including unsightly scarring with contractures occasionally leading to equinovarus deformities, long operative time, and poor quality and length of graft. Our objective was to develop a truly endoscopic method of sural nerve harvest using 1 small incision and 1 stab incision. METHODS: An endoscope designed for harvesting vascular conduits was used for nerve graft dissection. The nerve was then cut through a stab incision below the popliteal fossa. Sural nerve harvest was performed on 3 pediatric patients, aged 5 months to 3.5 years, between October and December of 2007. RESULTS: Nerve graft lengths were 9.5 to 13 cm. The mean operative time was 18 minutes from incision to graft removal and 36 minutes from incision to dressing placement. During all procedures, the brachial plexus exploration proceeded unimpeded during the graft harvest. Under microscopic inspection, the nerve grafts were much less damaged than those harvested previously with the stair-step technique. There were no complications during a mean follow-up period of 3 months. CONCLUSION: Advantages over previously described techniques include: 1) reduction from three or four 1.5-cm incisions to one 1.5-cm incision and one 3-mm incision, 2) a significant decrease in operative time, 3) increased ease of performing the graft harvest simultaneously with the brachial plexus dissection, and 4) a notable improvement in the graft, both in length and appearance.

Reconstruction of high ulnar nerve lesions by distal double median to ulnar nerve transfer.

Ulnar nerve lesions around the elbow often carry an unfavorable prognosis due to insufficient sensory and intrinsic muscle recovery. We present a series of 7 cases in which restoration of ulnar innervated intrinsic muscles of the hand and of skin sensibility was achieved. This was accomplished by a distal connection of the anterior interosseous nerve and the superficial sensory palmar branch of the median nerve to the motor and sensory components of the ulnar nerve at Guyon's canal. The length of the follow-up period ranged from 1 to 3.5 years. Results were graded by the Highet-Zachary scale. Good motor and sensory recovery was obtained in 6 cases; only return of protective sensation occurred in the remaining case.

[Transplantation of the vascular pedicled thoracicus longus nerve for recovering sensory capacities in the mentalis nerve supply region]. / Transplantation des gefässgestielten N. thoracicus longus zur Wiedererlangung sensibler Fähigkeiten im Versorgungsgebiet des N. mentalis

In the last few years microvascular techniques have improved the morphologic and functional results of reconstructive facial surgery. A main advantage is that neuronal rehabilitation can be achieved after tumor surgery. In this study the vascularized thoracic long nerve transplant was used for neuronal reconstruction of the alveolar inferior nerve after resection during tumor surgery. Five patients were examined for recurrence of neuronal function in the mental nerve and lip region after surgery in monthly control intervals. Sensation of pressure and pain was recorded for 3 months, sensation of contact and vibration feeling for 5 months and temperature sensation for 7 months after neuronal reconstruction. Nine months after surgery the mental nerve and lip sensitivity were the same on both sides--the reconstructed and the healthy side--in four patients. Thus, the vascularized thoracic long nerve seems to be a good nerve transplant for bridging defects of the alveolar inferior nerve after resection during tumor surgery.

Inferior alveolar nerve reconstruction with a polyglycolic acid bioabsorbable nerve conduit.

A custom-designed polyglycolic acid (PGA) bioabsorbable nerve conduit was used to reconstruct a 25-mm defect in the right inferior alveolar nerve. The initial nerve injury, following a dental extraction, resulted in loss of lower lip sensation and severe facial pain. Sixteen months after tooth extraction, with no improvement in symptomatology, the alveolar canal was enlarged in diameter by means of mandibular osteotomy to accommodate a 2-mm-diameter polyglycolic acid tube. The proximal end of the inferior alveolar nerve was sutured into the polyglycolic acid tube. The mental nerve was sutured into the distal end of the tube. Pain of neural origin was relieved in the early postoperative period. Two years following nerve reconstruction, pain relief remains excellent and perception of pressure and vibration is similar to the thresholds for these perceptions on the contralateral lip.