Stefano Artiaco

Chapter 14 End‐to‐Side Nerve Regeneration: From the Laboratory Bench to Clinical Applications

Translation of laboratory results to the patient is a critical step in biomedical research and sometimes promising basic science and preclinical results fail to meet the expectations when translated to the clinics. End-to-side (ETS) nerve regeneration is an example of an innovative neurobiological concept, which, after having generated great expectations in experimental and preclinical studies, provided very conflicting results when applied to clinical case series. A number of basic science studies have shown that ETS neurorrhaphy, in fact, is able to induce collateral sprouting from donor nerves axons, allowing for massive repopulation of the distal nerve stump. Experimental studies have also shown that ETS neurorrhaphy can recover voluntary control of skeletal muscles and that voluntary motor function recovery can be achieved both with agonistic and antagonistic donor nerves, thus widening the potential clinical indications. However, clinical case series reported so far, did not meet these promises and results have been rather conflicting, especially regarding repair of proximally located mixed nerves. In contrast, ETS reconstruction of distal sensory nerve lesions led to a more positive outcome and, most importantly, consistent results among international centers carrying out clinical trials. Concluding, ETS is a promising microsurgical approach for nerve coaptation, based on a convincing and innovative neurobiological concept. However, conflicting clinical results and disagreement among surgeons regarding its employment suggest that this technique should still be considered an ultima ratio, reserved for cases where no other repair technique can be attempted. New data coming from neurobiological research will help further enlarge the clinical indications of ETS nerve reconstruction, explain the different results found in laboratory animals and humans, and contribute to new treatments and rehabilitation strategies aimed at improving the efficacy of nerve regeneration after ETS neurorrhaphy.

Perforator-based propeller flaps treating loss of substance in the lower limb

BackgroundLocal flaps based on perforator vessels are raising interest in reconstructive surgery of the limbs. These flaps allow efficient coverage of large wounds without the need to sacrifice a major vascular axis. The operative technique does not require microvascular anastomosis and allows reconstruction of soft tissue defects using nearby similar tissues. The aim of this study was to evaluate the clinical results of local perforator flaps in the treatment of complex lower-limb defects.Materials and methodsTwenty-two local perforator flaps were retrospectively studied. Loss of substance was due to postsurgical complications in seven cases, oncological resection in six, posttraumatic defect in five, pressure sores in three, and osteomyelitis in one.ResultsPostoperatively, two patients showed partial flap necrosis. In five patients, a superficial epidermolysis occurred. Minor complications were seen in three patients who showed transient venous congestion of the flap. Furthermore, transient leg edema was sometimes observed in patients with large propeller flaps. All but one patient healed without further major surgical procedures. In three cases, secondary skin grafts were performed. In most cases, the aesthetic result was optimal and patients were fully satisfied.ConclusionsWhen characteristics of the defect are suitable for treatment with a propeller-based local flap, this technique should be considered as one of reasonable options for surgical reconstruction. Microsurgical techniques facilitate the management of complex trauma in emergency and may allow planning reconstructive procedures and limb salvage in elective orthopedic surgery.

Termino-lateral nerve suture in lesions of the digital nerves: clinical experience and literature review

Documented experience of treatment of digital nerve lesions with the termino-lateral (end-to-side) nerve suture is limited. Our clinical experience of this technique is detailed here alongside a systematic review of the previous literature. We performed, from 2002 to 2008, seven termino-lateral sutures with epineural window opening for digital nerve lesions. Functional outcome was analysed using the two-point discrimination test and the Semmes–Weinstein monofilament test. The results showed a sensory recovery of S3+ in six cases and S3 in one case. The mean distance found in the two-point discrimination test was 12.7 mm (range 8–18 mm). After a review of the literature, we were able to obtain homogeneous data from 17 additional patients operated by termino-lateral coaptation. The overall number of cases included in our review was 24. A sensory recovery was observed in 23 out of 24 patients. The functional results were S0 in one case, S3 in one case, S3+ in twenty cases and S4 in two cases. Excluding the one unfavourable case, the mean distance in the two-point discrimination test was 9.7 mm (range 3–18 mm). It can thus be concluded that the treatment of digital nerve lesions with termino-lateral suture showed encouraging results. Based on the results obtained in this current study we believe that in case of loss of substance, end-to-side nerve coaptation may be an alternative to biological and synthetic tubulisation when a digital nerve reconstruction by means of nerve autograft is declined by the patient.

Clinical Applications of End-to-Side Neurorrhaphy: An Update

End-to-side neurorrhaphy constitutes an interesting option to regain nerve function after damage in selected cases, in which conventional techniques are not feasible. In the last twenty years, many experimental and clinical studies have been conducted in order to understand the biological mechanisms and to test the effectiveness of this technique, with contrasting results. In this updated review, we consider the state of the art about end-to-side coaptation, focusing on all the current clinical applications, such as sensory and mixed nerve repair, treatment of facial palsy, and brachial plexus injuries and painful neuromas management.

Surgical treatment of acute fingernail injuries

The fingernail has an important role in hand function, facilitating the pinch and increasing the sensitivity of the fingertip. Therefore, immediate and proper strategy in treating fingernail injuries is essential to avoid aesthetic and functional impairment. Nail-bed and fingertip injuries are considered in this review, including subungual hematoma, wounds, simple lacerations of the nail bed and/or matrix, stellate lacerations, avulsion of the nail bed, ungual matrix defect, nail-bed injuries associated with fractures of the distal phalanx, and associated fingertip injuries. All these injuries require careful initial evaluation and adequate treatment, which is often performed under magnification. Delayed and secondary procedures of fingernail sequelae are possible, but final results are often unpredictable.

End-to-side nerve suture in traumatic injuries of brachial plexus: review of the literature and personal case series

We used end-to-side nerve coaptation combined with standard end-to-end neurotisations to treat 11 patients who presented with complete (six cases) or incomplete (five cases) traumatic brachial plexus injuries. All patients were available for functional evaluation at a minimum of 2 years postoperatively. In three patients with shoulder abduction recovery, electromyographical studies (EMG) showed a contribution from the end-to-side neurotisation. In the remaining cases end-to-side neurotisations were unsuccessful. Our study did not demonstrate a reliable role for end-to-side nerve suture in brachial plexus surgery. We believe that at present end-to-side suture must not be a substitute for standard reconstructive techniques in brachial plexus surgery. Occasionally termino-lateral nerve sutures may represent a support to standard reconstructive procedures especially in case of severe injuries when few undamaged donor nerves are available.

Chondrosarcoma in the distal phalanx of index finger: Clinical report and literature review

Chondrosarcoma is the most common primary malignant bone tumour of the hand. This aggressive lesion is extremely rare in the distal phalanx and requires differential diagnosis with enchondroma and onycomatrichoma which are specific neoplasms of this phalanx. We report a case of chondrosarcoma arising from left index distal phalanx, which developed over a long period of time with a progressive deformity of the distal phalanx before becoming painful. The patient was investigated with X-ray and MRI scan which demonstrated a locally aggressive lesion. The surgical procedure was discussed with the patient and consisted of a wide resection with distal phalanx amputation; this surgery left an acceptable functional impairment. Recently, the optimal treatment for chondrosarcoma of the finger has been debated in the literature and a more conservative surgical approach has been proposed. Local recurrence and metastasis have been reported in the literature. Thus, after surgical treatment, the patients should be followed with careful postoperative surveillance.

Dorsal metacarpal artery perforator-based propeller flap for complex defect of the dorsal aspect in the index finger

Construction Engineering Society). The risk of digital friction neuropathy of the thumb in line-workers has existed for some time; however, no cases have been reported to date. Surgical treatment for ‘‘bowler’s thumb’’ is neurolysis or the translocation of the nerve dorsal to or beneath the adductor muscle (De Smet et al., 1999; Dobyns et al., 1972). In this case, protection of the nerve with a digital soft pad was not feasible, and steroid infiltration around the nerve was ineffective, although it was reported to be useful in Morton’s neuroma (Rasmussen et al., 1996). External neurolysis of the affected digital nerve has relieved his symptoms.

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.

Pseudotumor of the Hip due to Fungal Prosthetic Joint Infection

Pseudotumors associated with total hip arthroplasty have been associated with metal-on-metal and metal-on-polyethylene total hip arthroplasties due to a granulomatous foreign-body reaction to methyl methacrylate, polyethylene, or metal ion release, but they have not been related to prosthetic joint infections. In this paper, we report an unusual case of Candida albicans total hip arthroplasty infection, causing a large inflammatory pseudotumor of the hip joint. Fungal periprosthetic joint infections are a rare clinical entity and difficult to diagnose, and a pseudotumor may be part of their clinical presentation. They should be suspected in immunodeficient host patients when clinical symptoms of prosthetic joint infections are observed.