Experimental and clinical employment of end-to-side coaptation: our experience.

The last 15 years have seen a growing interest regarding a technique for nerve repair named end-to-side coaptation. Since 2000, we have carried out experimental studies on end-to-side nerve repair as well as employed this technique to a series of selected clinical cases. Here we report on the results of this experience.For experimental studies, we have used the model represented by median nerve repair by end-to-side coaptation either on the ulnar (agonistic) or the radial (antagonistic) nerve. For time course assessment of median nerve functional recovery we used the grasping test, a test which permits to assess voluntary control of muscle function. Repaired nerves were processed for resin embedding to allow nerve fibre stereology and electron microscopy. Results showed that, in either experimental group, end-to-side-repaired median nerves were repopulated by axons regenerating from ulnar and radial donor nerves, respectively. Moreover, contrary to previously published data, our results showed that voluntary motor control of the muscles innervated by the median nerve was progressively recovered also when the antagonistic radial nerve was the donor nerve.As regards our clinical experience, results were not so positive. We have treated by end-to-side coaptation patients with both sensory (n = 7, collateral digital nerves) and mixed (n = 8, plexus level) nerve lesions. Results were good, as in other series, in sensory nerves whilst they were very difficult to investigate in mixed nerves at the plexus level.Take together, these results suggest that clinical employment of end-to-side coaptation should still be considered at the moment as the ultima ratio in cases in which no other repair technique can be attempted. Yet, it is clear that more basic research is needed to explain the reasons for the different results between laboratory animal and humans and, especially, to find out how to ameliorate the outcome of end-to-side nerve repair by adequate treatment and rehabilitation.

Functional and morphological assessment of a standardized crush injury of the rat median nerve.

The availability of effective experimental models for investigating nerve regeneration and designing new strategies for promoting this unique repair process is important. The aim of this study was to standardize a rat median nerve crush injury model using a non-serrated clamp exerting a compression force of 17.02 MPa for a duration of 30s. Results showed that functional recovery, evaluated by grasping test, was already detectable at day-12 and progressively increased until day-28 after which animal performance plateaued until the end of testing (day-42), reaching a range of 75-80% of pre-operative values. Morphological analysis on the median nerve segments, distal to the crush lesion, which were withdrawn at the end of the experiment showed that regenerated nerve fibers are significantly more numerous and densely packed; they are also smaller and have a thinner myelin sheath compared to controls. Together, these results provide a baseline characterization of the crush median nerve injury experimental model for its employment in the investigation of nerve regeneration research, especially when a reproducible regeneration process is required, such as for the study of biological mechanisms of peripheral nerve fiber regeneration or development of new therapeutic agents for promoting posttraumatic nerve repair.

Functional, morphological and biomolecular assessment of posttraumatic neuro-muscular recovery in the rat forelimb model.

Over the last five years, we have used the rat forelimb model for investigating neuromuscular recovery after microsurgical nerve reconstruction of median and ulnar nerves by end-to-side neurorrhaphy and muscle-vein-combined tubulization (using both straight and Y-shaped guides). The outcome of nerve repair at different postoperative times was assessed by functional, morphological and biomolecular analysis. Results showed that both end-to-side and tubulization repair of rat median and ulnar nerves led to successful axonal regeneration along the severed nerve trunk as well as to a partial recovery of the lost function as assessed by grasping test. Biomolecular analysis by means of reverse transcription polymerase chain reaction (RT-PCR) demonstrated early overexpression during nerve regeneration of the gliotrophic factor NRG1 and two of its receptors: erbB2 and erbB3. Finally, our experience also suggests that the rat forelimb experimental model is particularly appropriate for the study of microsurgical reconstruction of major mixed nerve trunks. Furthermore, since the forelimb model is less compromising for the animal, it should be preferred to the hindlimb model for many research purposes.

Origin and history of end-to-side neurorrhaphy.

This historical note offers a perspective concerning the origin of the employment of end-to-side (termino-lateral) anastomosis for nerve repair and summarizes the works that have been published on this surgical technique through the first part of the 20th Century. While the origin of end-to-side neurorrhaphy is usually dated to the beginning of the 20th Century, some works referring to this technique were published earlier, the first of which dates as far back as 1873. A number of interesting clinical and experimental studies have been carried out on end-to-side nerve anastomosis during the first years of the twentieth century. However, this literature is not easily detectable through current online scientific databases. In this paper we will give an overview of these early works. This history contributes interesting information to the debate surrounding this surgical concept and adds perspective to the use of a technique that has attracted a great deal of attention over the last 15 years.

Lack of topographic specificity in nerve fiber regeneration of rat forelimb mixed nerves.

Multiple nerve repair by means of a Y-shaped nerve guide represents a good model for studying the specificity of peripheral nerve fiber regeneration. Here we have used it for investigating the specificity of axonal regeneration in mixed nerves of the rat forelimb model. The left median and ulnar nerves, in adult female rats, were transected and repaired with a 14-mm Y-shaped conduit. The proximal end of the Y-shaped conduit was sutured to the proximal stump of either the median nerve or the ulnar nerve. Ten months after surgery, rats were tested for functional recovery of each median and ulnar nerve. Quantitative morphology of regenerated myelinated nerve fibers was then carried out by the two-dimensional disector technique. Results showed that partial recovery of both median and ulnar nerve motor function was regained in all experimental groups. Performance in the grasping test was significantly lower when the ulnar nerve was used as the proximal stump. Ulnar test assessment showed no significant difference between the two Y-shaped repair groups. The number of regenerated nerve fibers was significantly higher in the median nerve irrespectively of the donor nerve, maintaining the same proportion of myelinated fibers between the two nerves (about 60% median and 40% ulnar). On the other hand, nerve fiber size and myelin thickness were significantly larger in both distal nerves when the median nerve was used as the proximal donor nerve stump. G-ratio and myelin thickness/axon diameter ratio returned to normal values in all experimental groups. These results demonstrate that combined Y-shaped-tubulization repair of median and ulnar nerves permits the functional recovery of both nerves, independently from the proximal donor nerve employed, and that tissue, and not topographic, specificity guides nerve fiber regeneration in major forelimb mixed nerves of rats.

[Reduction mammaplasty using superior pedicle in macromastia]. / Place de la réduction mammaire à pédicule supérieur dans les gigantomasties.

SUBJECT: The authors present technical details, complications, morphologic and aesthetic results of 26 breast reduction mammaplasty for macromastia (breast reduction more than 1000 g) showing advantages and reliability of technique. MATERIALS AND METHODS: From January 2000 to December 2001, 223 patients underwent bilateral reduction mammaplasty with superior-based pedicled dermo-glandular flap. In 26 of them the weight of removed mammary tissue was over 1000 g in each breast. These 26 cases were evaluated, and the criteria adopted to analyse the results was morphologic and aesthetic evaluation of patient herself (very good, good, acceptable, unacceptable). RESULTS: Mean follow-up for all patients was 15 months. Twenty-six patients (mean age 33.2 years) underwent an average weight of 1131 g (930/2200 g) removed per breast. The following complications were observed: 1 Nipple Areolar Complex ischemia without necrosis; three infections (abscess); four delayed wound closure. The patient subjective evaluation of result was: "very good" in 19 cases (73%); "good" in 5 cases (19.2%) and "acceptable" in the others two cases (7.8%). No case was evaluated "unacceptable". CONCLUSION: Superior dermoglandular pedicle mammaplasty represent a very good and reliable solution for the treatment of macromastia, giving satisfactory cosmetics results with good nipple viability without necrosis. This technique is actually our first choice in the management of macromastia.

[The abdominal flap-graft for coverage of soft tissue defects of the dorsum of hand and fingers in burn patients. Six cases reports]. / Le lambeau-greffe abdominal: intérêt pour la couverture des pertes de substance tégumentaires dorsales de la main et des doigts chez le brûlé. A propos de six cas.

We report six cases of abdominal flap-graft used to cover post-burn soft tissue defects of hands. The technique used was first described by Colson and is applied in our study to an abdominal donor site. Debulking of the flap at the time of elevation resulted in a skin quality as good as a full thickness graft without jeopardizing flap vitality and reliability. Digit mobilization was possible after separation. Long term functional results were found to be satisfactory, specially for the hand. For the fingers it is mostly a digit-rescue surgery. The application of this technique remains sparse. Still, the abdominal flap-graft is often useful in cases of burn patients because of the poor local conditions, as well as the magnitude and nature of injury, which limit the coverage options.

[Dynamic correction of static scapholunate instability using an active tendon transfer of extensor brevi carpi radialis: preliminary report]. / Correction dynamique d'une instabilité statique scapholunaire par transfert tendineux actif du muscle court extenseur du carpe: rapport préliminaire.

We present the case of a twenty year old man who developed static scapholunate instability on the right side following a road traffic accident seven months previously. A dynamic surgical technique was devised to treat this problem using the tendon of extensor brevi carpi radialis as an active transfer. The tendon, divided at its insertion on the base of the third metacarpal, was reinserted into the distal part of the scaphoid using two anchors after shortening it by removing the distal centimetre. The tendon was rerouted via a pulley created 'de novo' at Lister's tubercle in order to centre the tendon on the same axis as the scaphoid. No other material was used for bone fixation. The wrist was immobilized in extension for six weeks. The clinical and radiological result eight months after the intervention showed excellent reduction of the scapholunate joint and a pain-free wrist with satisfactory mobility.

An anatomical study of the relationship between excursion of the flexor tendons and digital mobility: proposition of an intraoperative test for flexor tendon tenolysis.

The excursion of the flexor tendons of the thumb and fingers was studied in ten fresh cadaveric upper limbs. For each centimetre of tendon movement, obtained by traction of the flexor tendons at the wrist, the angular changes of the digital articulations were measured; movement started at extension and proceeded to maximum flexion. A further five upper limbs were used to evaluate the effect of pressure over the musculotendinous area of the flexor tendons of the fingers and thumb. Pressure on the muscle bellies in the forearm causes movement of the tendons, different for each finger, with the accompanying digital flexion depends on the magnitude of the movement. On the basis of this anatomical study a test is described which may be beneficial in the diagnosis of pathology and trauma of the flexor tendons and, particularly, in the intraoperative evaluation of the quality of motion obtained during tenolysis.

Direct muscle neurotization after end-to-side neurorrhaphy.

Over the recent years, end-to-side neurorrhaphy has reemerged in the literature for reconstructive nerve surgery. Another technique, in which interest has remained continuous during the last century, is direct nerve implantation into muscle belly, so-called direct muscle neurotization (DMN). In this work, the authors present a new technique to recover muscle innervation through direct nerve implantation into muscle belly, by means of a nerve graft, and sutured with end-to-side neurorrhaphy. They carried out experiments on 20 Wistar rats divided into two groups. In Group 1 (10 rats), on the right side, the peroneal nerve was sutured to the tibial nerve with end-to-side neurorrhaphy. Subsequently, the terminal branches of the same nerve were implanted in the anterior tibial muscle (ATM). On the left side, the peroneal nerve was severed, and the ATM completely denervated. In Group 2 (10 rats), on the right side, the same technique was used as in first group. On the left side, the normal innervation of the ATM was maintained. After 4 months, all muscles and nerves were harvested and evaluations carried out on the morphologic aspect, weight, and histology of the ATM, as well as the histology of the nerves. The authors analyzed the results, which demonstrated good reinnervation of the muscles deprived of any nerve connection.

[Subcutaneous peduncle flaps in reconstructive surgery]. / I lembi a peduncolo sottocutaneo in chirurgia ricostruttiva.

Among the varying forms of cutaneous flaps, V-Y flaps are finding an increasingly wide application in reconstructive surgery. Their use has been extended, depending on the cutaneous area in question, to various sizes of loss of substance. According to the type of tissues involved, the peduncle may be adipose, fascial or muscular. Vascularisation is random, but in those cases in which the base consists of muscle fascia an axial type is used since the peduncle generally corresponds to a well-known artery. V-Y flaps can repair defects measuring upto 5 cm in diameter and also guarantee a rotation of upto 90 degrees. The authors report their experience of 134 cases in which V-Y flaps were used in the reconstruction of loss of substance localised on the face, upper limbs, trunk, gluteal region, ear, leg and foot. The underlying pathologies consisted mainly of skin cancers, loss of substance following injury, scar retractions, syndactylia, decubitus ulcers in the gluteal region and a trophic foot ulcer. It was not necessary to re-operate any patient owing to problems linked to retraction or the unsightly appearance of residual scars. In the past V-Y flaps were indicated above all for the reconstruction of loss of face substance, but their use today has been extended to other districts. The authors highlight the advantages offered by V-Y flaps: ease and rapidity of use, the characteristics of the skin graft are identical to that removed, and the preservation of sensitivity.