[The asymptomatic thoracic outlet compression syndrome]. / Das asymptomatische Thoracic-outlet-Kompressionssyndrom.

The thoracic outlet compression syndrome has a great number of clinical variations. Arterial and venous perfusion impairment is an associated symptom, nerve irritation can occur with or without vascular problems. The degree of nerve damage ranges from transient irritation to permanent motoric and sensory defects. The lack of space in the supracostoclavicular compartment is the cause for nerve compression. The degree of neural damage depends on the degree and duration of the compression. Anatomic variations between the clavicle and first rib are frequent causes for the TOS: accessory ribs and muscles, and fibrous bands have been described. A preexisting chronic compression may lead to a subclinical TOS, in this case an inadequate trauma of minor degree may be sufficient to manifest a plexus palsy. Intraoperative findings in children with incomplete and complete brachial plexus palsy and the corresponding findings in adults prompted us to present this communication.

Cellular mechanisms of rejection and regeneration in peripheral nerve allografts.

A model of rejection and regeneration of peripheral nerve allografts in rats is presented. A 2.5-cm segment of 28 right sciatic nerves was transplanted orthotopically from LEW.1W to DA and from DA to LEW.1W. With a microsurgical technique, proximal and distal coaptations were performed. In an autologous control group the same surgical procedure was applied. Evaluation included clinical estimation of motor recovery and macroscopic appearance of the graft, electrophysiological examination, conventional histology, and immunohistology. The latter concentrated on demonstration of monomorphic and polymorphic determinants of MHC class I and II antigens and of macrophages. By functional, electrophysiological, and histological parameters it was demonstrated that after rejection a certain degree of regeneration took place in the allografts. Both rejection and subsequent regeneration were studied in detail by immunohistology. During the course of Wallerian degeneration MHC class I expression on myelin sheaths could be demonstrated. When the rejection response occurred, additional MHC class II expression on myelin sheaths and on vascular endothelial was observed. Recipient specific class I-positive macrophages were infiltrating the graft from the epineurium and the coaptation sites, and were later present at the sites of myelin degradation. At 6 weeks postoperatively donor-specific MHC products were no longer detectable, but recipient-specific Schwann cells were present in the allograft tissue. We conclude that a rejection response renders a peripheral nerve allograft acellular but does not destroy the nerve architecture, still enabling it to function as an axon conduit. The regeneration in the rejected allograft however lacks the positive neurotropic and -trophic influence physiologically provided by viable Schwann cells.

The cervical rib. A predisposing factor for obstetric brachial plexus lesions.

Controversy surrounds the aetiology of obstetric brachial plexus lesions. Most authors consider that it is caused by traction or compression of the brachial plexus during delivery. Some patients, however, present without a history of major traction during delivery, and some delivered by Caesarean section also suffer the injury. In our series of 42 infants, 28 had an Erb's palsy, and the remaining 14 presented with a more extensive lesion, involving the lower roots. In five of these, a complete ossified cervical rib was found. We believe that anatomical variations, such as cervical ribs or fibrous bands, can cause narrowing of the supracostoclavicular space, and render the adjacent nerves more susceptible to external trauma.

Replantation of the complete external genitals.

Most cases of genital amputation represent an isolated penile amputation; the combined amputation of both penile and testes is reported very seldom. We describe a case of complete amputation of the external genitals with successful replantation and good functional outcome. The problem is analyzed with respect to operative strategy, ischemic periods, postoperative management, and psychiatric background. For the replantation of the testes, time frames are comparable to those for macroreplantations.

[Therapy of soft tissue trauma in the acute phase of severe hand injuries]. / Therapie des Weichteiltraumas in der Akutphase von schweren Handverletzungen.

INTRODUCTION: Complex hand injuries are characterized by a combination of soft tissue injury and additional trauma to functional structures such as nerves, bones, tendons, vessels and joints. A good functional result requires the reconstruction of the injured structures and early mobilisation. Good vascularized soft tissue and stable osteosyntheses are the major prerequisites to avoid infections and to allow early mobilisation. The optimal timing for soft tissue reconstruction remains controversial with respect to the incidence of infections. METHODS: We have evaluated retrospectively our series of complex hand injuries addressing the question whether a delay of soft tissue coverage for up to 72 hours causes significant increase of infection rates. RESULTS: 48 patients were treated with complex injuries of the hand within a three year period between December 1998 and December 2000. The lowest incidence of infections occurred in the group, where soft tissue coverage was completed as an emergency procedure. DISCUSSION: Ideally primary reconstruction of complex hand injuries should be strived for to minimize scar formation as a result of secondary operations and further immobilisation periods. This includes, if necessary, free tissue transfer. Exceptions are situations where the vitality of soft remains uncertain. In these cases, definitive surgery is delayed for a maximum period of 72 hours.

[The Dellon tube in injuries of peripheral nerves]. / Die Dellon-Röhrchen bei Verletzungen peripherer Nerven.

Experimental efforts are being undertaken to improve nerve transplantation as a method for peripheral nerve repair. Major disadvantages of nerve transplantation are the creation of neurologic deficits at the donor site and the limited availability of nerve grafts. Mackinnon and Dellon propose the interposition of synthetic, biodegradable tubes as a nerve conduit for clinical use. This method is described according to its theoretical background and the surgical technique. The interposition of synthetic tubes seems possible for short defects in finger nerves, but will render unfavourable results in long defects of peripheral mixed nerves.

[Opposition-plasty after brachial plexus lesions by osteosynthesis]. / Oppositionsplastik nach Plexus brachialis-Läsionen durch Osteosynthese.

Secondary reconstruction of lost muscle function in brachial plexus injuries is performed by dynamic muscle and tendon transposition, by free microvascular muscle transplantation and by static surgical procedures. In cases of weak function of the finger flexors, static opponensplasty is required. In these cases our procedure is the internal fixation of the base of the metacarpal I to the base of the metacarpal II without stabilisation of cancellous bone. From 1987 to 1992 we operated 15 patients by this procedure. Results are showing sufficient stabilisation and good function.

[Intraoperative histological sections in obstetric brachial plexus lesions--comparison of macroscopic appearance, HE staining and toluidine blue staining]. / Intraoperative Schnellschnittdiagnostik bei der geburtstraumatischen Plexusläsion - Gegenüberstellung von Makroskopie, HE-Schnellschnitten und Semidünnschnitten mit Toluidinblau-Färbung.

In brachial plexus lesions and their revision, evaluation of nerve stumps is very important for the reconstructive strategy. We intraoperatively perform cryostat sections, Haematoxilin-Eosin (HE) stained, and compare the clinical appearance of the nerves to the microscopic results. Toluidine blue staining is later used to validate the structural details. Intraneural fibrosis can be traced safely with both staining methods, in root avulsions a histology is helpful, too. For more proximal, intraforaminal lesions semithin section stained with toluidine-blue are less informative than are HE-stained cryostat sections. In these lesions the clinical control by electrical stimulation and evoked potentials is superior.

[Reconstruction of defects at the neuromuscular junction]. / Rekonstruktion bei Defekten im neuromuskulären Ubergang.

Loss of muscle tissue at the area of the neuromuscular junction after tumor resection or after trauma precludes the reconstruction with conventional nerve grafts, because the distal nerve stump is absent. For these cases, we recommend direct insertion of the nerve grafts into the muscle. We describe a standardized technique, which has been performed in 19 patients and led to a mean motor recovery of grade M4 after Highet. The key procedure of this technique is the interfascicular dissection of the nerve grafts, which allows a wide distribution of the grafts into the muscle tissue.

[A comparison of different treatment methods of pseudarthroses and recurrent pseudarthroses of the scaphoid]. / Ein Vergleich unterschiedlicher Behandlungsmethoden von Pseudarthrosen und Rezidivpseudarthrosen des Skaphoids.

From 1981 to 1990 110 scaphoid non-unions were operated on in our clinic. The period from 1986 to 1990 was followed up. During this time, 45 cases were surgically treated: 27 by Matti-Russe plasty, 11 by Herbert screw, and 7 by vascularized radial bone graft. The following criteria were compared: 1. Radiological signs of healing; 2. Period of immobilization; 3. Clinical results. The shortest period of immobilization and best wrist function was observed in patients treated by Herbert screw.

[Timing of free microsurgical tissue transplantation in hand injuries during the acute phase]. / Zeitpunktwahl der freien mikrochirurgischen Gewebetransplantation bei Handverletzungen in der Akutphase.

Due to favourable survival rates in replantation surgery and a high standard of free tissue transplantation, the interval between injury and microsurgical reconstruction has continuously decreased in the past. The acute phase can be defined as the interval ranging from emergency procedures within 24 hours to "urgence différée" procedures within 72 hours. Bearing in mind the infection rates of 1.5% and 17.5% respectively as it has been reported in the literature, we should encourage emergency reconstructions. However, in most cases of upper extremity injuries, reconstruction with conventional flaps is possible. Between 1981 and 1991, 674 free tissue transplantation have been performed in our unit, 61% of the cases of free tissue transplantations to the upper extremity were done in the acute phase, the majority within 72 hours (urgence différée). No significant differences in rates of infections were evident comparing acute phase and urgence différée procedures. Because of this, we still support the concept of urgence différée. In our opinion the following advantages have to be considered: urgence différée allows a second loop operation, the vitality of the extremity can be ascertained, and the reconstructive procedure can be planned more precisely. Last not least, a procedure performed during the day-time assures better operating conditions. This concept is demonstrated with clinical cases.

[Time limited immunosuppression in allogenic nerve transplant in the rat]. / Die zeitlich begrenzte Immunsuppression am allogenen Nerventransplantat der Ratte.

A rejection response of peripheral nerve allografts eliminates the Schwann cells without destroying the tubular architecture and leads to a regeneration of inferior quality. Under immunosuppression this rejection is prevented, and allogenic Schwann cells persist in the grafts, leading to a better regeneration result. In adult rats of the strains DA and LEW.1W, a 2,5 cm segment of the sciatic nerve was grafted. Under Cyclosporin A regeneration was allowed to take place for 12 weeks. Thereafter, immunosuppression was discontinued in one group and gradually reduced in another. Regeneration quality was compared after an additional six weeks in comparison to an autologous control. Best regeneration was observed in the autologous control; no statistical differences were observed between the two experimental groups. Gradual reduction of immunosuppression did not result in an atraumatic replacement of donor derived Schwann cells by recipient derived ones. Allogenic nerve grafting needs continuous immunosuppression, which to date precludes it from clinical application.

[Regeneration of peripheral nerves after interposition of acellular muscle into larger defects]. / Regeneration peripherer Nerven nach Interposition grösserer Defekte durch azellulären Muskel.

Peripheral nerve grafting is an established procedure in reconstructive surgery. Nerve grafts, however, are only available to a limited extent and patients are faced with neurologic deficits at the donor areas. Pretreated skeletal muscle has been proposed as an alternative grafting material. In nine adult Sprague-Dawley rats, a 2 cm gap of the sciatic nerve is grafted with a M. gracilis segment which has been pretreated through repeated freezing and thawing. Regeneration is evaluated after six weeks postoperatively. The results are compared to nine conventional nerve grafts. Regeneration was evident in all grafts. Histologically, the muscle grafts revealed a high proportion of connective tissue, a good vascularisation but an inferior degree of myelinisation. Morphometrically, the muscle grafts proved to be inferior according to axon counts and myelinisation. Muscle grafts provide a substrate comparable to peripheral nerves regarding the tubular architecture based on laminin. There are however no viable Schwann cells within these substitutes, which makes them inferior compared to conventional nerve grafts for peripheral nerve repair. These results are discussed with respect to further experiments concerning allogeneic nerve grafting and peripheral nerve preservation.

[Muscle-specific changes in free latissimus dorsi transplantation in the rat model]. / Muskelspezifische Veränderungen bei der freien Latissimus dorsi-Transplantation im Rattenmodell.

The aim of this study is to gain further knowledge concerning the regeneration of reinnervated, freely transplanted muscles. Therefore, we used a rat model, consisting of eight rats per group, in which the latissimus dorsi muscle was transplanted orthotopically, after a period of time of two and twelve weeks harvested, then evaluated histologically and enzyme-histochemically. As controls we used a group of non-operated muscles. At date of removal, the patency of the vascular anastomoses was checked clinically and histologically. Additionally, electrophysiological measurements and conventional and enzyme-histochemical histologies were performed. Two weeks after the free neurovascular flap transplantation, the muscle was not innervated yet, histologically a dissolved pattern of type 1 and type 2 muscle fibers was found. After twelve weeks of time, the muscles were reinnervated again, muscle contraction was positive after electrical stimulation and the typical pattern of fibers was reestablished.

Timing of free microsurgical tissue transfer for the acute phase of hand injuries.

Because of favourable survival rates in replantation surgery and a high standard of free tissue transfer the interval between injury and microsurgical reconstruction has become gradually shorter. The acute phase can be defined as the interval ranging from emergency procedures within 24 hours to urgent procedures done within 72 hours. Bearing in mind the infection rates that have been reported of 1.5% for the acute phase and 17.5% for the late phase, we should encourage emergency reconstructions. However, in most cases of upper extremity injuries, reconstruction with conventional flaps is possible. Between 1981 and 1995 we did 72 acute post-traumatic free tissue transfers to the upper extremity in our unit within 72 hours (urgently). There were no significant differences in the incidence of infections when acute were compared with urgent procedures. As a result we support the concept of urgent operations. The following advantages are to be considered: urgent operations allow a second look operation, the viability of the extremity can be assessed, and the reconstructive procedure can be planned more precisely. Last but not least, the procedure is done during the day time with better operating conditions.

Peripheral nerve allografts: survey of present state in an experimental model of the rat.

Rejection and regeneration processes in peripheral nerve allografts are analyzed in this review of a series of experiments with special reference to the possible clinical application of peripheral nerve allografting in clinical reconstructive surgery. A long segment of the sciatic nerve (2.5 cm) was grafted between congenic rat strains across a maximal genetic barrier; immunohistologically, donor- and recipient-derived structures can be differentiated. If allografting was performed without immunosuppression, a rejection response with consecutive regeneration of minor quality was observed. Under immunosuppression with cyclosporin A no rejection response was observed and regeneration quality was comparable to control autografts. The persistence of donor-derived Schwann cells in the immunosuppressed allografts can be demonstrated immunohistologically. After discontinuation of immunosuppression a rejection response is exerted. We conclude that Schwann cells are eliminated from peripheral nerves during rejection. Consecutive regeneration of minor quality is possible, which implies the ingrowth of recipient-derived Schwann cells into the rejected allograft. Under immunosuppression, allogenic Schwann cells survive and actively promote regeneration. They are still immunologically competent and can exert rejection when immunosuppression is discontinued. A certain degree of replacement of donor-derived Schwann cells seems possible.

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.

[Surgical replantation]. / Replantationschirurgie.

In the early days of replantation surgery, if viability was restored the operation was judged a success. Nowadays restoration of viability alone is not sufficient to fulfill the criteria of successful replantation, which are as follows: Lack of severe systemic disturbances due to the replantation, a "functional extremity" according to the definition of Chen et al. (1978), no or little pain at the site of the replantation, good aesthetic results, and an acceptable length of time for rehabilitation and return to normal life. Successful replantation needs a therapy concept that is based on an exact definition of the amputation injury from the viewpoint of the amount of severance, the level of the amputation, and the type of amputation mechanism, complete knowledge of current replantation indications, and exact selection of patients amenable for replantation.

Preservation of peripheral nerve grafts with Schwann cell culture medium.

Preservation of peripheral nerves may, in the near future, play an important role in reconstructive surgery, especially if recent advances in immunosuppressive therapy are taken into account. Therefore, it has to be investigated whether peripheral nerves can be stored for some time after harvesting without diminishing their regenerative potential. Previous experiments of our group could demonstrate only little benefit of organ storage solution (HTK) or normal saline (NaCl 0.9%) to peripheral nerves when kept at cold ischaemia of 4 degrees C for 32 and 72 hours. In this presentation, we are reporting the results of peripheral nerve storage in Dulbecco's Modified Eagle Medium which has been used for Schwann cell culture. In 30 adult Sprague-Dawley rats, a 2.5 cm segment of the right sciatic nerve was harvested and kept at 4 degrees C for 14, 32, 72, and 120 hours. It was then reimplanted into the donor animal; regeneration quality was assessed clinically, histologically and morphometrically after 6 weeks. Best regeneration results were obtained in the 32 and 72 hour groups; regeneration here was comparable to the normal controls. These results are explained with the positive effect of nerve predegeneration.

Regeneration of autologous and allogenic nerve grafts in a rat genetic model: preliminary report.

The authors report observations concerning rejection and regeneration processes of allogenic peripheral neural tissue, depending on different genetic mismatches in a rat model. Five groups representing different rat strains (n = 100) were subjected to orthotopic grafting of 2.5-cm segments of sciatic nerve. Combinations represented different genetic barriers, including the Major Histocompatibility Complex (MHC), a non-MHC, a subgroup (A) of the MHC, a group representing MHC plus non-MHC, and an autologous control group. Animals were examined after one, two, and 12 weeks; additional evaluations in some of the experimental groups were done at six and eight weeks. Regeneration in varying degrees was evident in all groups at 12 weeks.