Hemihypoglossal nerve transfer for acute facial paralysis.

OBJECT: The authors have developed a technique for the treatment of facial paralysis that utilizes anastomosis of the split hypoglossal and facial nerve. Here, they document improvements in the procedure and experimental evidence supporting the approach. METHODS: They analyzed outcomes in 36 patients who underwent the procedure, all of whom had suffered from facial paralysis following the removal of large vestibular schwannomas. The average period of paralysis was 6.2 months. The authors used 5 different variations of a procedure for selecting the split nerve, including evaluation of the split nerve using recordings of evoked potentials in the tongue. RESULTS: Successful facial reanimation was achieved in 16 of 17 patients using the cephalad side of the split hypoglossal nerve and in 15 of 15 patients using the caudal side. The single unsuccessful case using the cephalad side of the split nerve resulted from severe infection of the cheek. Procedures using the ansa cervicalis branch yielded poor success rates (2 of 4 cases). Some tongue atrophy was observed in all variants of the procedure, with 17 cases of minimal atrophy and 14 cases of moderate atrophy. No procedure led to severe atrophy causing functional deficits of the tongue. CONCLUSIONS: The split hypoglossal-facial nerve anastomosis procedure consistently leads to good facial reanimation, and the use of either half of the split hypoglossal nerve results in facial reanimation and moderate tongue atrophy.

A New Surgical Technique for Polysyndactyly of the Toes without Skin Graft.

Reconstruction for polysyndactyly of the toes aims at cosmetic improvement. A previous method that uses a skin graft has inherent disadvantages of mismatched pigmentation between the graft and the surrounding skin and scar formation at the donor site. The authors' new improved surgical technique for the treatment of polysyndactyly of the toes does not require a skin graft and therefore avoids these problems. The authors designed a subcutaneous flap from the distal portion of a rectangular flap of skin from the dorsal side of the interdigital webbing and moved the former flap to the sidewall of the base of a toe. Both flaps are the same size; therefore, an interdigital space had to be of sufficient size to accommodate both of them. To ensure an adequate blood supply to the flap, careful handling of the subcutaneous flap is essential for success. This procedure can apply to polysyndactyly of the fourth, fifth, and sixth toes when the fourth and fifth toes adhere over the distal side of the distal interphalangeal joint and when the skin on the dorsal side of the fifth toe, regarded as the excessive one, is at lease twice the size of the dorsal rectangular flap. Ten patients with polysyndactyly of the toe were treated with this method. Aesthetically good results were obtained.

Collateral sprouting occurs following end-to-side neurorrhaphy.

Recent evidence supports the use of end-to-side neurorrhaphy for the treatment of certain peripheral nerve disorders. However, the mechanism by which nerves regenerate following this procedure is still unclear. To address this question, the authors designed a new end-to-side coaptation model in rats in which the donor nerves were uninjured. The regenerated axons at the coaptation site were observed directly using fluorescent dye as the neural tracer. The sciatic nerve from adult Wistar rats was transplanted between the left and right median nerves. Fifteen rats were divided into three groups. In group I, the donor (right median) nerve was sutured end to side to the divided grafted nerve using a noninjury technique. In group II, the aponeurosis of the spinal muscles was harvested and the sciatic and right median nerves were coapted end to side noninjuriously by wrapping them in the excised aponeurosis. In group III, a perineurial window was created and a partial neurectomy was carried out at the suture site, after which the sciatic and right median nerves were sutured end to side. Sixty days after the operation, nerve regeneration was evaluated by recording action potentials in the grafted nerve, by performing electromyography in the flexor muscles in the forearm, and by histological examination. The grafted nerves were fixed and sectioned, the number of regenerated nerve fibers was counted, and axonal diameters were measured. Fluorescent dye crystal was used, in conjunction with confocal microscopy, to observe the regenerated axons at the co-aptation site. The results showed that nerve regeneration had occurred in the animals, as determined electrophysiologically and histologically. Both the right and left flexor muscles of the forearm contracted simultaneously as a result of indirect electric stimulation of the grafted nerve, which suggests that the regenerated nerve was physiologically connected with the donor nerve. Nerve fiber counts did not show any differences among groups (p > 0.05), but axonal diameters were significantly greater in group III than in the other two groups. Fluorescent dye staining revealed the presence of regenerated nerve fibers beyond the coaptation site. In group III, the regenerating nerves were observed within the whole section of the coaptation site and collateral sprouting was found to occur even at a site distal to the suture. From these results, the authors conclude that in end-to-side neurorrhaphy, nerve regeneration occurs by collateral sprouting from the donor nerve.