[Anatomical Identification and Possibilities of Transfer of the Masseteric Nerve for Facial Reanimation]. / Anatomische Auffindbarkeit und Möglichkeiten des Transfers des Nervus massetericus zur Gesichtsreanimation.

BACKGROUND: The masseteric nerve (MN) is often used as a donor nerve for facial reanimation. In addition to already established techniques, MN transfer is rapidly gaining importance, mainly due to the single-stage approach of the procedure and its reconstructive potential. This anatomical study and the associated questionnaire study aimed to evaluate the established methods for identification of the MN and its suitability for direct nerve transfer as well as to assess the importance of MN transfer in the daily clinical routine. MATERIAL AND METHODOLOGY: Bilateral dissection of 25 fresh-frozen head specimens (n=50; 13 female, 12 male) was performed with accompanying measurement of the MN. In a questionnaire study conducted at established centres for facial surgery in German-speaking countries, clinical experience data of MN transfer was collected using the SurveyMonkey software. The data obtained was statistically analysed using Microsoft Excel and presented in numerical tables and boxplots. RESULTS: Using anatomical landmarks such as the zygomatic arch and the mandibular notch for orientation, the MN was found in 100% of cases. Its average length from the emerging point below the zygomatic arch towards its entry into the masseter muscle was measured to be 22 mm and was the length available for nerve transposition. Tension-free coaptation of the MN with the zygomatic branch was possible in 94% of cases. The questionnaire showed that the MN is considered an important donor nerve for motor nerve transfers and that MN transfer is now largely established as a standard procedure. DISCUSSION: In accordance with previously published studies, the MN was reliably found at the height of the mandibular notch and, in the vast majority of cases, was suitable for tension-free coaptation with the zygomatic branch. Differences to the existing literature, however, can be seen in the length of the nerve available for nerve transposition and the frequency of its division into several branches before entering the masseter muscle. In German-speaking countries, Cross-Face Nerve Grafting (CFNG) is still the preferred method for facial reanimation surgery. However, MN transfer is also well established by now, both as an alternative and a supplement to other techniques, possibly due to its low donor site morbidity and short time to regeneration.

[Perioperative Diagnostics of Peripheral Nerve Lesions and Compression Syndromes: Position Paper of the German-Speaking Group for Microsurgery of Peripheral Nerves and Vessels]. / Diagnostik von peripheren Nerven bei Läsionen und Kompressionssyndromen: Positionspaper der Deutschsprachigen Arbeitsgemeinschaft für Mikrochirurgie ­ (DAM).

The treatment of peripheral nerve pathologies requires a rapid and precise diagnosis. However, the correct identification of nerve pathologies is often difficult and valuable time is lost in the process. In this position paper of the German-Speaking Group for Microsurgery of Peripheral Nerves and Vessels (DAM), we describe the current evidence for various perioperative diagnostics for the detection of traumatic peripheral nerve lesions or compression syndromes. In detail, we evaluated the importance of clinical examinations, electrophysiology, nerve ultrasound and magnetic resonance neurography. Additionally, we surveyed our members for their diagnostic approach in this regard. The statements are based on a consensus workshop on the 42nd meeting of the DAM in Graz, Austria.

[New Technologies in Microsurgery: Potential, Indications and Economical Aspects - Report of the Consensus Workshop of the German-Speaking Society for Microsurgery of Peripheral Nerves and Vessels (DAM)]. / Neue Technologien in der Mikrochirurgie: Potential, Indikationen und ökonomische Aspekte ­ Konsensus-Bericht der Deutschsprachigen Arbeitsgemeinschaft für Mikrochirurgie der peripheren Nerven und Gefäße (DAM).

Recently, several new technologies to support microsurgeons have received European market approval. This article summarizes and discusses the impressions of an expert panel to classify the potential of new technologies in terms of benefits for the surgeon, specific indications and economic aspects during the 42nd Annual Meeting of the German-speaking Working Group for Microsurgery of Peripheral Nerves and Vessels (DAM) in Graz, Austria. In general, the expert panel addressed the principles and prerequisite for the successful establishment of new technologies and, in particular, novel optical and robotic systems. For this purpose, the current scientific literature was reviewed and initial clinical experience in the context of case series and retrospective studies was presented by the members of the expert panel. In the ensuing discussion, it was pointed out that it will first be necessary to identify patient subgroups in which the use of the new technologies is most likely to achieve a clinical benefit. Since clinical approval has already been granted for some systems, an approach can be developed for immediate clinical application from the simplest possible use to ever finer applications, i. e. from microsurgery to supermicrosurgery. Initially, funding for cost-intensive systems would presumably not be possible through revenue from standard care, but only through grants or subsidized clinical trials. In a final survey, the majority of meeting participants see the need for a price reduction of both visualization and surgical robotics technologies to enable widespread clinical establishment. Likewise, a majority of participants would prefer a combination of an exoscope or robotic microscope and a surgical robot for clinical use. The present consensus work addresses the development of a strategy for the effective establishment of new technologies, which should further increase the surgical quality of selected interventions.

Donor site morbidity after the harvest of microvascular flaps from the medial and lateral femoral condyle region: Objective, radiologic, and patient-reported outcome of a multi-center trial.

BACKGROUND: With the experience-based hypothesis of low donor site morbidity (DSM) for free flaps from the distal femur, this cohort study aimed to evaluate the DSM according to objective and reproducible criteria. METHODS: One hundred and fifty-six patients who had a flap harvest from either the medial or lateral femoral condyle region between 2005 and 2017 were included. A retrospective chart review was performed for all patients. In total, 97 patients were available for a follow-up examination. Outcomes were assessed according to objective (Knee Society Score; Larson Knee Score; OAK Score; 0-100 points), patient-reported (IKDC Score; KOOS Score; 0-100 points), and radiologic criteria (Kellgren and Lawrence Score; MRI Osteoarthritis Knee Score). RESULTS: The median follow-up time was 1529 days (range: 248-4,810). The mean Knee Society Score (94.8 ± 10.1), Larson Knee Score (94.5 ± 10.1), and OAK Score (95.5 ± 6.6) showed nearly unimpaired knee function. The overall patient-reported DSM was low (IKDC Score: 86.7 ± 17.4; KOOS Score: 89.3 ± 17.1). Osteochondral (OC) flaps had a significantly higher DSM, regardless of the donor site. Bone flaps did not show any relevant radiologic morbidity in the Kellgren and Lawrence Score. Besides the procedure-associated cartilage lesions at the OC donor sites, MRI Osteoarthritis Knee Score did not show any significant presence of further knee pathologies in the bilateral MRI Scans. The obvious cartilage lesions did not have a relevant impact on the knee function of most patients. CONCLUSION: The DSM for bone and soft-tissue flaps from the femoral condyle region is negligible. OC flaps are associated with a significantly higher DSM, although a clinically relevant impact on knee function was not evident in the majority of patients.

Occult Pathologic Findings in Reduction Mammaplasty in 5781 Patients-An International Multicenter Study.

Breast cancer is among the most commonly diagnosed cancers in the world, affecting one in eight women in their lifetimes. The disease places a substantial burden on healthcare systems in developed countries and often requires surgical correction. In spite of this, much of the breast cancer pathophysiology remains unknown, allowing for the cancer to develop to later stages prior to detection. Many women undergo reduction mammaplasties (RM) to adjust breast size, with over 500,000 operations being performed annually. Tissue samples from such procedures have drawn interest recently, with studies attempting to garner a better understanding of breast cancer's development. A number of samples have revealed nascent cancer developments that were previously undetected and unexpected. Investigating these so-called "occult" findings of cancer in otherwise healthy patients may provide further insight regarding risk factors and countermeasures. Here, we detail occult findings of cancer in reduction mammaplasty samples provided from a cohort of over 5000 patients from 16 different institutions in Europe. Although the majority of our resected breast tissue specimens were benign, our findings indicate that there is a continued need for histopathological examination. As a result, our study suggests that preoperative imaging should be routinely performed in patients scheduled for RM, especially those with risk factors of breast cancer, to identify and enable a primary oncologic approach.

Nerve decompression according to A.L. Dellon in Morton's neuroma - A retrospective analysis.

BACKGROUND: First reported by Dellon et al. in 1992, nerve decompression by dissecting the deep transversal intermetatarsal ligament through a dorsal incision appears to be a reliable method for treating Morton's neuroma by addressing its underlying pathomechanism, since it should rather be considered as Morton's entrapment. As there are no current studies dealing with Dellon's surgical technique, we carried out a retrospective analysis with the aim of showing that nerve decompression is an effective method to treat Morton's neuroma, and one that considers its true pathology. MATERIALS AND METHODS: All patients with a clinical diagnosis of Morton's neuroma, verified by MRI and treated by nerve decompression were included in this study in the years from 2010 to 2018 at our department. Follow-up was performed at least six months post-intervention; pain and function history were ascertained using the VAS (visual analogue scale) score and the German foot function index. Skin sensitivity testing was performed using Semmes-Weinstein monofilaments. RESULTS: A total of 12 patients were treated and followed-up during the study period. Postoperatively, there was significant improvement in the values of the VAS score both under strain (p-value: 0.0021) and at rest (p-value: 0.0062), as well as in the foot function index (p-value: 0.0022). There was no significant difference in skin sensitivity of the innervation areas of the interdigital nerves of the affected foot compared with the healthy reference foot (p-value: 0.0968). CONCLUSION: Dellon's decompression method yielded a highly positive outcome, and based on our findings, we consider it a reliable, technically simple and promising approach to treat Morton's neuroma. It is a minimally invasive technique that addresses the pathomechanism of peripheral nerve entrapment and has a low rate of complication as well as rapid patient recovery.

[Non-invasive correction of congenital ear deformities with the EarWell Correction System: a prospective study]. / Nicht-invasive Korrektur angeborener Ohrfehlbildungen mit dem EarWell Infant Ear Correction System: Eine prospektive Studie.

BACKGROUND: Congenital ear deformities occur in 5 % of all newborns. Molding of the ear is possible during the first six weeks of life because of the maternal hormones which are still circulating in the newborns. For several years we have been using the EarWell™ Correction System, which allows us to correct ear deformities within the first weeks of life. PATIENTS AND METHODS: This prospective study included 19 newborns. The following ear deformities were treated: cup ear, lop ear, steel ear, helical rim abnormalities, antihelical rim abnormalities. The results of the EarWell™ system were reevaluated two years after the procedure. Two independent examiners evaluated the clinical results on the basis of preand postprocedural pictures. In addition, the following parameters were evaluated: time of application, complications, satisfaction of parents, cost comparison between the EarWell™ system and otoplasty. RESULTS: In all, 32 ears were treated with the EarWell™ system. 63 % were male and 37 % female. The system was placed in the first three weeks of life. The average treatment time was 12-28 days. The rate of complications was 1.3 %. The clinical results were rated as follows: 23 % very satisfactory, 35 % fully satisfactory, 30 % satisfactory, 3 % less satisfactory and 9 % not satisfactory. 95 % of the parents would use the EarWell™ system again. The costs of the EarWell™ system are EUR 660, those of otoplasty EUR 2826. CONCLUSION: Ear deformities are easily treated with the EarWell™ system during the first weeks of life. It reduces the need for surgical correction at a later age and prevents children from further stress. Another advantage is the low costs compared with the costs of otoplasty.

[Free latissimus dorsi muscle flap for scalp reconstruction in elderly patients with a squamous cell carcinoma]. / Freie M. latissimus dorsi Lappenplastik zur Defektdeckung des Capilitiums bei ausgedehnten Plattenepithelkarzinomen des alten Patienten.

BACKGROUND: Scalp defects resulting from the resection of a squamous cell carcinoma often require free tissue transfer. In these cases, a free latissimus dorsi muscle flap is a good possibility to cover scalp defects. Our aim was to evaluate the outcome of scalp coverage with free latissimus dorsi muscle flaps. METHODS: This retrospective analysis included 4 patients aged over 70 years (7082), who underwent scalp reconstruction with a free latissimus dorsi muscle flap and a split-skin graft after the resection of a squamous cell carcinoma. Patient characteristics, histological findings, recurrence rate, postoperative radiotherapy, duration of operation and in-patient stay were recorded. RESULTS: All 4 patients had recurrent tumours and the follow-up period was 12-48 months. Histological findings demonstrated R0 resection in all patients. A PALACOS® bone was necessary in two patients and duraplasty in one. All free flaps healed without major complications. There was no flap loss; minor complications included seromas and wound dehiscence. One patient died during follow-up and two were no longer treatable due to tumour progression. One patient is still alive and has had no recurrence for 22 months. CONCLUSION: Free latissimus dorsi muscle flap is a reliable method to reconstruct large scalp defects, even in elderly patients, due to its low complication rate and good tissue vascularity. Despite R0 resection with partial resection of the skullcap and duraplasty, there is a high risk for local recurrence. A multidisciplinary approach is necessary to achieve the best therapy concept for each patient.

[Long-term experience with Collagenase Clostridium Histolyticum (CCH, Xiapex®) for the treatment of Dupuytren's contracture: lessons learned]. / Langzeiterfahrung mit Collagenase Clostridium Histolyticum (CCH, Xiapex®) zur Behandlung der Dupuytrenschen Kontraktur: Lessons learned.

INTRODUCTION: CCH (Collagenase Clostridium Histolyticum; Xiapex®) has become established as a simple and reliable alternative to traditional treatments for Dupuytren's contracture. This study aims to analyse our results and discuss our modifications of this therapy. PATIENTS AND METHODS: The study included 312 fingers treated with CCH between 2011 and 2018 (256 patients; 225 men and 31 women). There were 157 fingers (50.3 %) with an isolated joint contracture, while multiple joints were affected in 155 fingers (49.7 %). The average age at surgery was 65.8 years. The follow-up period averaged 41.2 weeks. A retrospective data analysis evaluated our results and the effect of our technical modifications on treatment success. RESULTS: The average presurgical degree of contracture was 63.3 degrees. The average contracture reduction compared to the initial value was 94 % immediately after surgery and 81 % at the last follow-up. There were skin cracks in 22.1 %. The postsurgical course was uneventful in 99.4 %, with minor complications in 0.6 %. The recurrence rate was 14.4 % Extension of the time interval until stretching (24 vs. 48 hours) had no significant effect on the immediate success rate or the rate of skin lesions. CONCLUSIONS: If the indication is chosen correctly and the treatment is performed by an experienced surgeon, the success rate with CCH is comparable to other current treatment options.

[Therapy of Dupuytren's contracture with collagenase - Evidence-based Consensus Statement of Austrian Surgical Societies]. / Therapie der Dupuytren'schen Kontraktur mit Kollagenase.

Dupuytren's contracture (DC) or Dupuytren's disease (DD) is a progressive fibro-proliferative disease of palmoplantar connective tissue, resulting in characteristic nodal and/or cord formation from collagen disposition. When the disease progresses, the thickening and shortening of the cords eventually leads the affected fingers to being pulled into flexion, which may be associated with marked disability, especially with bilateral disease. DD is relatively common in Europe, with the highest prevalence in Nordic countries. In Austria approx. 200 000 people are affected. The incidence increases with increasing age, with men being more often and earlier affected than women. The aetiology of DC is not completely clear, but it seems to be multifactorial; twin and familial studies confirm a genetic predisposition. The natural course of the disease can vary between relatively benign and massive progression and recurrence. In most cases, there is a fluctuating course. The DC is not curable; treatment methods range from minimally invasive to open surgical procedures. Collagenase Clostridium histolyticum (CCH) is a nonsurgical, enzymatic injection treatment for adult patients (≥ 18 years) with a palpable cord and has been approved in Europe since 2011. Clinical studies and practical experience of individual centres confirm the efficacy and safety of CCH treatment of DC. The present consensus statement was prepared under the auspices of the Austrian Society of Hand Surgery with the participation of the Austrian Society for Trauma Surgery, the Society of Orthopaedics and Orthopaedic Surgery as well as the Society for Plastic, Aesthetic and Reconstructive Surgery. On the basis of current literature and the experts' experience, it describes the various surgical procedures, with particular reference to collagenase treatment and provides guidance for their use. The statement is intended not only to illustrate the state of the art of current treatment, but also to support the achievement of uniform high quality standards in the treatment of DC in surgical centres and specialised medical practices throughout Austria.

[Foucher's first dorsal metacarpal artery island flap]. / Insellappenplastik der ersten dorsalen Mittelhandarterie nach Foucher.

OBJECTIVE: Coverage of soft-tissue defects of the thumb, which cannot be covered primarily or with a skin graft, by a neurovascular pedicled island flap from the dorsum of the index finger. INDICATIONS: Combined skin and soft-tissue defects of the back of the hand, the thumb web space, and especially the thumb. CONTRAINDICATIONS: Damages to the first dorsal metacarpal artery or the rete carpale dorsale. Previous injuries to the flap donor area. Local infection. SURGICAL TECHNIQUE: Outlining of the skin flap design on the dorsum of the index finger. S-shaped skin incision at first web space radially. Identification of the first dorsal metacarpal artery and preparation of a fascioneurovascular pedicle for flap supply, with involvement of the fascia of the dorsal interosseous muscle in the flap pedicle. Intersection of the island flap from the index finger. Preparation and uplifting of the flap. Tunneling of the island flap under a skin bridge into the covering defect on the thumb. Fixation and suturing of the flap in the defect. Coverage of the flap defect on the dorsum of the index finger with a skin graft. POSTOPERATIVE MANAGEMENT: Immobilization with a cast for 7 days, followed by finger mobilization and wound care. RESULTS: During the years 2005 and 2006, 15 major soft-tissue defects of the thumb in eleven men and four women were reconstructed using a neurovascular island flap of the first dorsal metacarpal artery. The results were comparable to those previously reported in the literature. All flaps healed completely without any complications. The two-point discrimination measured an average of 8.8 mm.

[Distally pedicled posterior interosseous artery flap for the coverage of defects on the wrist and hand]. / Die distal gestielte Arteria-interossea-posterior-Lappenplastik zur Defektdeckung am Handgelenk und an der Hand.

OBJECTIVE: Coverage of defects on the upper limb with the distally pedicled, fasciocutaneous posterior interosseous artery flap. INDICATIONS: Defects with exposed tendon and/or bony tissue on the palmar and dorsal side of the wrist, the hand upon the proximal interphalangeal joint level and the whole thumb. Coverage of defects on the palmar side of wrist and palm of the hand with exposed median and/or ulnar nerve. Enlargement of the 1st interdigital web space in cases of thumb adduction contracture. CONTRAINDICATIONS: Surgery at the flap harvesting site on the proximal third of the forearm. Surgery at the site of the flap pedicle on the middle and distal third of the forearm upon the distal radioulnar joint. Absence of the distal anastomosis between the anterior and posterior interosseous arteries at the level of the distal radioulnar joint (5% of the cases). SURGICAL TECHNIQUE: Skin markings of the planned island flap and subsequent S-curved skin incision along the flap pedicle upon the level of the distal radioulnar joint; blunt dissection onto the forearm fascia. Incision of the forearm fascia between the extensor digitorum communis and extensor digiti minimi muscles. Dissection of the flap pedicle between the extensor digiti minimi and extensor carpi ulnaris muscles with subsequent identification of the posterior interosseous artery (no dissection!). Skin incision around the flap island. Dissection and ligation of the proximal anastomosis between the anterior and posterior interosseous arteries; mobilization of the flap island and pedicle from the ulnar shaft. Mobilization can be performed until the distal anastomosis of the anterior and posterior interosseous arteries is reached (flap pivot point). POSTOPERATIVE MANAGEMENT: Plaster immobilization of the wrist and/or fingers for 7 days. Start of occupational therapy from the 7th postoperative day. Removal of sutures on the 12th-14th postoperative day. Wearing of compression garments. RESULTS: From November 2005 until June 2007, 25 distally pedicled posterior interosseous artery flaps were performed. With this type of flap, it was possible to successfully enlarge the 1st interdigital web space in two patients and to cover the whole thumb in two cases of degloving injury. In nine patients, the flap was used to cover the median and/or ulnar nerve at the level of the wrist and/or palm of the hand, and in four cases, to cover defects after tumor resection on the palm of the hand. Exposed extensor tendons and/or bony structures were covered with this flap in another eight patients. In two of the 25 flaps, distinct necroses of the most distal edge of the skin island were seen. After surgical debridement and split-skin transplantation, all of these small superficial defects healed well. Absence of the distal anastomosis as well as complete flap failure could not be observed in this series.

[The dorsal flag flap for skin coverage of finger and thumb-tip injuries]. / Der dorsale Fähnchenlappen zur Defektdeckung im Finger- und Daumenbereich.

OBJECTIVE: Immediate two-step coverage of dorsal finger and thumb-tip soft-tissue defects with a dorsal flag flap, which can bridge over two fingers if necessary. INDICATIONS: Soft-tissue defects on the dorsal aspect of fingers between the metacarpophalangeal and the distal interphalangeal joint as well as on the tip of the thumb. CONTRAINDICATIONS: Large defects, complex hand trauma, need of a sensible thumb tip, infections, noncompliance. SURGICAL TECHNIQUE: Marking of the flap at the middle phalanx and its flagpole pedicle, containing the dorsal digital artery. The breadth should reach to the middle of the finger and the proximal pole should not cross the middle of the proximal phalanx. With tourniquet dissection of the flap above the peritendineum with respect of the dorsal digital artery and subcutaneous veins in the pedicle. Opening of the tourniquet, in the case of flap perfusion transposition of the flap into the defect. Coverage of the donor site with skin graft. POSTOPERATIVE MANAGEMENT: Palmar cast splinting in intrinsic-plus position for 1 week, followed by physiotherapy. Pedicle separation after 3 weeks. Continuation of physiotherapy and scar care. RESULTS: In 2006, ten patients were operated on, three of them for reconstruction of the thumb tip. All patients showed a survival of the flap and a good wound healing without complications. One patient developed a flexion contracture at the donor finger due to noncompliance following immobilization. The functional and aesthetic results were satisfactory in all patients, the average DASH Score ("Disabilities of the Arm, Shoulder and Hand") was 16.4, mainly due to the residuals of the overall injury.

Microneurovascular anatomy of the peroneus brevis muscle in the NZW-rabbit: a new model for free functional muscle transplantation.

This study introduces the peroneus brevis muscle of the NZW-rabbit as a new model for free functional muscle transplantation. The muscle originates from the lateral aspect of the knee joint and inserts on the 5th metatarsal with a circumscript tendon. It can be harvested with a 7 cm long motor nerve branch. In a series of 22 animals divided in two groups with a body weight of 3.19 +/- 0.30 kg and 4.81 +/- 0.38 kg respectively, vessel diameter of the supplying artery was found to be 0.3-0.35 mm in group one and 0.40-0.45 mm in group two, the two concomitant veins were 1.1-1.4 mm in diameter in the first group and 1.2-1.6 mm in the second group. Histomorphometric analysis stained with NADH showed 3.67 +/- 3.21% type I fibers, 25.41 +/- 7.87% type IIa fibers, and 70.93 +/- 9.12% type IIb/d fibers.

Should dermal scald burns in children be covered with autologous skin grafts or with allogeneic cultivated keratinocytes?--"The Viennese concept".

The treatment of scald burns in children is still under discussion. The aim of the present study was to evaluate an optimised treatment regime for scald burns in children. Between 1997 and 2002, 124 children underwent surgical intervention due to burn injuries. Thirty-six out of these 124 children were enrolled into the evaluation of our recent treatment protocol. Twenty-two children with scald burns covering an average body surface area (TBSA) of 18.5% were treated by early excision and coverage with allogeneic keratinocytes in case of partial thickness lesions (keratinocyte group). Fourteen children with a TBSA of 17.2% were treated with autologous skin grafts alone (skin graft group). Both groups were comparable according to age, burn depth and affected TBSA. The complete clinical follow-up examination of at least 17 months was performed in 12 out of 22 children of the keratinocyte group and in 9 out of 14 patients of the comparative group. Visible scar formations were classified according to the Vancouver Scar Scale (VSS) in each patient. The use of allogeneic keratinocytes led to complete epithelialisation within 12 days in 20 of the 22 cases. No secondary skin grafting procedures had to be done. Skin take rate at the sixth postoperative day was 100% in the skin graft group. Blood transfusions were administered intraoperatively according to the clinical need of the patients by the responsible anaesthesiologist. The mean volume of blood, which had to be transfused was 63.9 ml in the keratinocyte group and significantly lower than the volume of 151.4 ml, which was administered in the skin graft group (p=0.04). At follow up the VSS observed in areas covered by keratinocytes was 2.33 on the average and therefore, significantly lower than the VSS of 5.22 in skin grafted areas of the comparative group (p=0.04). In children the use of cultivated keratinocytes in partial thickness scald burns is a procedure, which renders constantly reliable results. It minimizes the areas of autologous skin harvesting and reduces the amount of blood transfusions. The fact that less scarring is observed after keratinocyte grafting leads to the conclusion that skin grafting in children should be restricted to scalded areas, which have to be excised to the subcutaneous fat tissue.

Neuroma prevention by end-to-side neurorraphy: an experimental study in rats.

PURPOSE: The successful treatment of painful neuromas remains a difficult goal to attain. In this report we explore the feasibility of neuroma prevention by insertion of the proximal end of a nerve through an end-to-side neurorraphy into an adjacent mixed nerve to provide a pathway and target for axons deprived of their end organ. METHODS: Experiments were performed on a total of twenty 250-g Sprague-Dawley rats. Two groups of 10 animals were prepared. Group A served as an anatomic control. In group B the right saphenous nerve was transected and implanted end-to-side through an epineurial window into the tibial nerve distal to the trifurcation of the sciatic nerve. After 12 weeks the corresponding sensory neurons were identified by retrograde labeling techniques and histomorphometric analysis of the proximal and distal tibial nerve segments, and regular histology of the end-to-side site were performed. RESULTS: The results of the retrograde labeling of the corresponding sensory neuron pool of the saphenus nerve showed extensive labelling of the L1 to L3 spinal ganglions after intracutaneous tracer application of the planta pedis. The morphology of the end-to-side coaptation site and histomorphologic analysis prove that sensory neurons penetrate the perineurial sheath and axons regenerate along the tibial Schwann cell tubes toward their targets. CONCLUSIONS: Axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented. Whether these axons will lead to disturbing sensations such as paresthesia or dysesthesia in the newly found environment or remain silent codwellers, this experiment cannot answer. Long-term results of future clinical work will have to decide whether the prevention of the neuroma through end-to-side coaptation will be an appropriate therapy for this difficult problem.

Limits of muscle-to-nerve ratio in functional muscle transplantation.

The aim of the present study was to investigate the functional limits of over-dimensioning a free functioning muscle transplant for neuromuscular reconstruction. A part of the rectus femoris muscle, two and three times bigger than a scutuloauricularis muscle, was used to functionally replace the latter after removal. The major finding of these experiments is that both double-sized and triple-sized portions of the rectus femoris muscle developed maximal tetanic tensions during isometric contractions, which were up to 175 percent of the control scutuloauricularis muscle of the unoperated, contralateral side, although the same branch of the facial nerve was used for reinnervation of the grafted muscle. This implies that the supplying branch of the facial nerve has the potency to innervate a muscle much larger than the originally supplied muscle with optimal efficiency. These results underline the usefulness of overdimensioning during functional muscle transplantation, and also in limited neural capacity situations.

Impact of duodenal feeding on the oxygen balance of the splanchnic region during different phases of severe burn injury.

Enteral nutrition is recommended in burned patients. Depending on the amount administered, enteral feeding causes an increase of intestinal oxygen-demand. Since intestinal perfusion is decreased after major burns the aim of this study was to evaluate, whether duodenal feeding might be a cofactor for the development of a splanchnic O(2)-imbalance. In 15 severely burned patients during duodenal feeding starting within 6 h after injury the assessment of the CO(2)-gap between arterial and gastric CO(2), as a parameter for the measurement of intestinal O(2)-balance was performed. Beginning prior to enteral nutrition CO(2)-gap measurements were carried out to show when the CO(2)-gap increased above 30 mmHg during the whole critical illness phase of the patients. When the CO(2)-gap increased above 30 mmHg enteral nutrition was reduced by 50% and the CO(2)-gap was measured 1 h later. In none of the patients the CO(2)-gap increased during increase of enteral nutrition. In seven patients, the CO(2)-gap increased between the 6th and 13th day above 30 mmHg and fell significantly 1 h after reduction of enteral nutrition. Contrary to the early postburn phase, enteral feeding might have adverse effects on the oxygen balance of the intestine in the later stages of the critical illness phase.

The use of allogeneic cultivated keratinocytes for the early coverage of deep dermal burns - indications, results and problems.

Since 1995, keratinocytes are grown into cultures and used as allografts for the coverage of deep dermal defects in our burn unit. Donor skin samples are mostly acquired from other burn patients. In addition, special methods of skin preservation allow us the use of skin, which has been taken in redundancy for split thickness skin grafting from nonburned patients.Thirty five patients with deep partial thickness burns in the face were treated since 1996 according to the following concept: Dermabrasion or tangential excision was performed before the 5(th) day following trauma. If viable dermis was present, the wounds were covered with sheets of allogeneic cultivated keratinocytes. In cases of deeper defects, autologous skin grafts were applied. In 23 cases, epithelialisation was achieved within 10 days, in 8 patients, a prolonged duration until complete healing was observed. In 5 faces, coverage of residual defects with skin grafts was necessary. The mentioned problems of wound healing occurred from infection, incomplete excision of burn eschar and a depth of the wound which was retrospectively seen too deep for the treatment with keratinocytes. At follow up, patients were examined clinically and functionally with Frey's faciometer(R), which is an instrument for quantification of mimic movements. In cases of uncomplicated healing, a nearly complete restitution was found.Other indications include deep dermal burns in children and the coverage of early excised wounds in adults, with a reasonable amount of viable dermis remaining, both resulting in a significant reduction of donor-site morbidity. In severely burned adults with limited donor sites, it offers the possibility of immediate definite coverage of large areas.