Nerve allografts are highly antigenic and require the continuous use of immunosuppressive drugs. Neurotoxic complications from immunosuppressant therapy with FK 506 have been noted in the central and peripheral nervous system although an increased rate of axonal regeneration has also been noted. Regeneration of peripheral nerve grafts was assessed in a rat model clinically and morphometrically after treatment for 2 and 6 weeks with two different doses of FK 506. Good regeneration was noted in all groups at 6 weeks. A significantly higher axon count was observed in both the FK 506 groups after 2 weeks regeneration compared with controls. This beneficial effect was not evident after 6 weeks of regeneration. Whether this is related to a pruning mechanism or to a down-regulation of regenerative processes in the nerve due to possible neurotoxic effects of FK 506 remains unknown.

Acellular muscle grafts can support axonal regeneration over short gaps. Due to the lack of viable Schwann cells in the grafts, failure of regeneration is evident with increasing gap lengths. To create a biological nerve conduit, Schwann cells were implanted into acellular muscle. The grafts were then incubated in vitro and assessed histologically and morphometrically. For cultivation of the Schwann cells, rat sciatic nerves were allowed to predegenerate to obtain a high cell yield. Rat gracilis muscles were harvested and made acellular by a liquid nitrogen treatment. After Schwann cell implantation, the muscles were incubated in vitro for 2, 5, and 7 days. S100-immunostaining, NGF, and N-cadherin, characterized the Schwann cells within the muscle. Viability was assessed by fluoresceine-fluorescence staining. Proliferation was determined by BrdU-DNA incorporation. Cell implantation did not to affect Schwann cell viability. Cells were seen throughout the entire length of the muscle basal lamina. They aligned and formed a cell column. Immunostained for S-100, implanted cells showed 100 percent staining. N-cadherin and NGF were expressed by all of the S-100 positive cells. Predegeneration is considered to be a highly efficacious method, if a high yield of activated Schwann cells is required. The successful implantation of the cells into an acellular muscle provides the possibility of a biologic conduit, offering the advantage of large basal lamina tubes serving as a pathway for regenerating axons. It also provides the beneficial effects of viable Schwann cells that produce neurotrophic and neurotropic factors to support axonal regeneration. Functional outcomes require evaluation in further in vivo studies.

The underlying cause of primary lymphedema is a malformation of the lymph vessel system. Secondary lymphedemas can be due to infections, recurrent inflammation, hypoproteinemia, tumors, operations, or irradiation. As a reaction to persistent edema and interstitial macromolecules, fibrosis occurs. Recurrent inflammations of the indurated and edematous tissue are clinically impressive. The massive form of the scrotal lymphedema leads to painful tautness and sexual dysfunction. A concurrent penile edema can cause dysuria. The deformity of the affected extremities and organs not only leads to restriction of mobility but also to psychological stress due to the disfigurement, even as far as to social deprivation. We report on a surgical technique for treating pronounced scrotal edema by resection and neoscrotal reconstruction using ventral pedunculated scrotal skin flaps in cases of congenital hereditary elephantiasis of the Meige type.

A 16-year-old female sustained a subtotal amputation of the left thigh. Debridement resulted in a bone and soft-tissue defect of 20 cm in length. The whole quadriceps muscle was lost, and the knee joint was open. The femur was stabilized by transfer of corticocancellous bone grafts. A latissimus dorsi muscle was harvested and transferred to reconstruct the lost quadriceps muscle. The thoracodorsal nerve was coaptated to the motor branch of the femoral nerve. The years after trauma, the muscle provides excellent motor function. EMG evaluation reveals no sign of denervation; macro-electromyography reveals only a moderate enlargement of motor units. There is recruitment of all motor units. Maximum voluntary torque of the transplanted muscle has decreased, compared to the contralateral rectus femoris. Histologic evaluation demonstrates a normal skeletal muscle with typical fiber distribution. These results indicate complete adaptability of the muscle at an atypical site, with a high degree of functional and structural plasticity of the skeletal muscle. The decreased voluntary torque of the transferred latissimus dorsi depends on the lower, total-fiber, cross-sectional area--the result of a parallel fiber structure.

A common peroneal nerve palsy caused by a ganglion cyst is a rare entity. A 48-year old man was referred with a six year history of intermittent pain that had resulted in a complete palsy of the common peroneal nerve. A magnetic resonance (MR) scan showed compression of the nerve by a ganglion, which was excised and the nerve was released. Three months later the lost muscle function had returned completely.