[The "safe" flap - Preoperative perforator-mapping and intraoperative perfusion assessment to reduce flap-associated morbidity - Consensus statement of the German Speaking Working Group for Microsurgery of the Peripheral Nerves and Vessels]

Reconstructive microsurgery using free and pedicled flaps has become a reliable method with a high success rate. Preoperative perforator mapping and intraoperative assessment of perfusion might further reduce flap-associated morbidity.There are various techniques for perforator mapping and perfusion measurement, but no guidelines regarding their use. Therefore, an expert panel at the 40th Annual Meeting of the German-Speaking Working Group for Microsurgery of the Peripheral Nerves and Vessels (DAM) discussed and critically reviewed the current literature. The consensus statement represents the expert opinion based on the available literature and provides recommendations regarding the use of preoperative perforator mapping and intraoperative perfusion measurement.

Multivariate Data Analysis Using Persistence-Based Filtering and Topological Signatures

The extraction of significant structures in arbitrary high-dimensional data sets is a challenging task. Moreover, classifying data points as noise in order to reduce a data set bears special relevance for many application domains. Standard methods such as clustering serve to reduce problem complexity by providing the user with classes of similar entities. However, they usually do not highlight relations between different entities and require a stopping criterion, e.g. the number of clusters to be detected. In this paper, we present a visualization pipeline based on recent advancements in algebraic topology. More precisely, we employ methods from persistent homology that enable topological data analysis on high-dimensional data sets. Our pipeline inherently copes with noisy data and data sets of arbitrary dimensions. It extracts central structures of a data set in a hierarchical manner by using a persistence-based filtering algorithm that is theoretically well-founded. We furthermore introduce persistence rings, a novel visualization technique for a class of topological features-the persistence intervals-of large data sets. Persistence rings provide a unique topological signature of a data set, which helps in recognizing similarities. In addition, we provide interactive visualization techniques that assist the user in evaluating the parameter space of our method in order to extract relevant structures. We describe and evaluate our analysis pipeline by means of two very distinct classes of data sets: First, a class of synthetic data sets containing topological objects is employed to highlight the interaction capabilities of our method. Second, in order to affirm the utility of our technique, we analyse a class of high-dimensional real-world data sets arising from current research in cultural heritage.

[Vermilion reconstruction after dog bite injuries]

Dog bite injuries often concern the lips. In children, injuries of the face are most common, but also in adults so-called kissing injuries frequently happen. All-layer defects are treated by wedge excision in minor cases and by myocutaneous flaps in major cases of lower lip injuries, whereas upper lip defects are reconstructed by exchange flaps. If only the vermilion is concerned, mucosal flaps according to the von Esmarch technique yield very good aesthetic results with excellent function and without impairment of the mouth opening.

[Incomplete anterior interosseous nerve syndrome in a guitar player]

A rare case of median nerve compression syndrome is reported in a guitar player who had changed the posture and position of his instrument so that the edge of the guitar exerted sharp pressure on the median nerve close to the branching of the interosseous anterior nerve. There was partial paralysis of the interosseous anterior nerve with complete failure of the deep flexor of the index finger, while the flexor pollicis longus was intact. There was also paresthesia of the index finger. Treatment was conservative with a sleeve including a gel cushion which protected the forearm against the edge of the instrument. Function recurred completely within six weeks without ever interrupting instrument practice.

[Improvement of chronic pain syndrome by free tissue transfer. Report of two cases]

We report on two patients with chronic pain syndrome of a lower limb due to chronic constriction after radiation therapy in one case and to popliteal entrapment in the other. The patients had been in pain therapy for years and had achieved insufficient analgesia in one case and satisfactory analgesia in another case with high doses of morphine sulphate and other medication. Surgery was indicated for limb salvage in one patient, and for pain relief in the other patient. It consisted of decompression and defect reconstruction by free latissimus dorsi flaps. In both cases, after an uncomplicated follow-up, quick and complete weaning from the analgesics was possible. One of the patients is completely free of pain.

[A manual boring device for Kirschner wires]

A new surgical instrument is presented that is designed for manual placement of Kirschner wires. Its construction is based on that of a micro-screwdriver. The whole instrument is cannulated for wires of any length up to a gauge of 1.2 mm. This instrument facilitates smooth placement of Kirschner wires in difficult situations, especially in hand surgery.

[In vivo staining with the fluorescence marker PKH26 in experimental fat cell transplantation. Technique and initial results]

Experimental autologous adipocyte transplantation has to cope with the problem of differentiation between transplanted fat cells and local fat tissue of the recipient site. In this paper we present a procedure for marking vital fat cells and for tracking them over more than 6 months. An adipocyte suspension is marked by PKH26 ZynLinker (Zynaxis, Malvern, PA) and reimplanted into the animal. In a confocal microscope, the fluorescent dye is easily detected, and the varying intensity of the signal helps to differentiate between viable adipocytes, necroses, and oil cysts. An image analyzing system (OPTIMAS) allows for automatic planimetry and stereometry for viable and necrotic cells. Hence, the ratio between viable and necrotic transplanted cells can be measured exactly for the first time in fat transplantation research.

[Surgical replantation]

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.

[Bilateral biceps replacement-plasty by transposition of the latissimus dorsi muscle in arthrogryposis multiplex congenita. A case report]

The case of a four-year old girl with arthrogryposis multiplex congenita is reported. Primary clinical examination revealed bilateral passive elbow flexion only 0-20-70 without active elbow flexion. A two-stage operative procedure was chosen for both sides. At first an elbow arthrolysis was performed with subsequent intensive physiotherapy. In a second session we performed a bipolar transposition of the latissimus dorsi as a myocutaneous flap. The patient was first operated on the left and afterwards on the right side. By this procedure, the patient achieved a significant improvement of both passive and active elbow flexion mobility. The range of active motion was 0-30-90 and 0-40-90 degrees.

True aneurysms of the palmar arch of the hand: a report of two cases

We report on two cases of true aneurysms of the palmar arch, both of which were post-traumatic. One was due to repetitive blunt trauma and the other to a glass cut wound. Both aneurysms were detected clinically as pulsating masses without functional disorders. The presence of elastic fibres and smooth muscle in the aneurysm wall proved it to be a true aneurysm. Both aneurysms were excised and replaced by a vein graft from the foot.

[Traumatic aneurysms of the hand. Description of 5 cases]

We report about three cases of true aneurysm in the finger artery and one in the superficial palmar arch. Three of these developed after blunt trauma. Vascular reconstruction was performed either by direct suture or using a venous graft. Another case of a false aneurysm after finger replantation is reported.

Vascular complications after free tissue transfer

Between 1981 and 1992, 631 cases of free tissue transfer were operated on at our clinic. Of these cases, 489 were reviewed for vascular complications. The aim of the study was to evaluate retrospectively possible correlations between complications and operative faults. Vascular complications occurred in 16%. By immediate operative revision 50% of the cases with a vascular complication could be salvaged. In general, earlier diagnosis and treatment of vascular complications after free tissue transfer prompted a higher success rate of the surgical revision.

Routine monitoring in patients with free tissue transfer by laser-Doppler flowmetry

The use of laser Doppler flowmetry (LDF) was tested in 108 consecutive patients, who underwent free tissue transfer at our institution between December, 1988, and June, 1990. Sixteen patients (14.8%) suffered vascular complications, which could be detected in all cases earlier by LDF than by clinical examination alone. LDF therefore prompted faster surgical intervention in these cases, allowing flap salvation in 9.3% (n = 10). Difficulties had to be noted in diagnosing venous thrombosis by means of the LDF due to sometimes unspecific alterations in LDF signals. Technical improvement of LDF might lead to a higher diagnostic accuracy if venous thrombosis occurs.

Techniques of postoperative blood flow monitoring after free tissue transfer: an overview

Ever since free tissue transfer has been established in microsurgery, success rates have greatly improved over the years, partly due to improved technical performance of microvascular anastomoses with better optical and instrumental aids. However, flap failure still occurs in 5-10%, mainly due to blood vessel thrombosis within the first 24 postoperative hours. Salvation rates of failing free tissue transfers can be optimized by in-time diagnosis of irreversibly compromised tissue blood flow and immediate operative reexploration. Therefore, there is a special demand for adequate and reliable postoperative monitoring techniques. This article gives an overview of all monitoring techniques, which have been performed both in the experimental and clinical setting thus far.

[Computer-assisted optimization of dialysis treatment]

In some dialysis centers of the GDR personal computers are introduced step by step. There are two main areas in the use of computers in dialysis centers: data management systems and computer-assisted individualization of dialysis. Type and size of data processing are the result of the specific information process in a dialysis center and the presence of a long-term constantly group of patients along with a stereotypical amount of data. In the mathematical modelling of dialysis it is possible to adapt the standard dialysis to each patient.

[Post-traumatic arthrosis of the upper ankle joint in chronic insufficiency of the fibular ligament]

X-ray studies of the ankle joints of 209 patients with operatively certified ankle joint instability were examined retrospectively in order to estimate the importance of lateral instability in causing degenerative osteoarthritis of the ankle joint. The patients were distributed into two groups: group A (126 patients with chronic fibular instability; 98 were up to 29 years of age and 28 between 30 and 40 years) and group B (83 patients with a fresh fibular rupture: 70 up to 29 years and 13 between 30 and 40 years). For more subtle differentiation of the grades of osteoarthritis, a new score system was developed. The results were tested statistically. In the patients with chronic instability in the younger group signs of degenerative arthritis could be seen twice as frequently as in the recently injured patients; in particular, higher grades of arthritis were found five times more frequently than in the recently injured. All patients with chronic instability in the older group had signs of degenerative arthritis. Higher grades of degenerative arthritis occurred ten times more frequently than in the recently injured. Regarding the recently injured patients, there was no significant difference between the younger and the older group. It is concluded that chronic fibular instability is an important factor in the development of degenerative arthritis, which shows the importance of early stabilization in order to prevent the development of degenerative arthritis.

[Intra-articular pressure measurement. A new method for the use of the pressure measuring film "Prescale"]

We present a new procedure to protect Pressure measuring film from moisture and to facilitate its application in sphaerical joints without crinkles, shearing or friction artefacts. The film is cut into narrow laminas and embedded between two layers of an OP-site-foil. After this treatment, the film is still able to be gauged and even to bear a gas sterilization without any loss of measuring range or accuracy.