P Tos

Università degli Studi di Torino, Torino, Piedmont, Italy

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Publications (32)37.88 Total impact

  • Source
    Article: Secondary repair of flexor tendon injuries.
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    ABSTRACT: Tendon adhesions or even secondary ruptures causing severe hand functional impairment still represent a frequent complication after repair of flexor tendon injuries. Secondary treatment of these problems includes tenolysis, one or two stages flexor tendons reconstruction by grafts or even the use of tendon prosthesis. The mechanism and severity of injury, the status of the surrounding tissues and injured finger, the presence of associated lesions, the age of the patient, post-operative management, patient motivation and the surgeon's skill, may all have implications in the final outcome of the tendon reconstruction. A correct evaluation of the problem by means of classifications such as the one described by Boyes, may help the surgeon in choosing the appropriate technique.
    Injury 01/2013; · 1.98 Impact Factor
  • Article: La sindrome compressiva del nervo interosseo anteriore (sindrome di Kiloh-Nevin)
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    ABSTRACT: Among compression neuropathies of the median nerve in the forearm we discuss the one affecting the anterior interosseous nerve (AIN), called Kiloh-Nevin syndrome. Literature is confusing since several sites of compression are enclosed in a misleading nomenclature. Diagnosis is mostly clinical but electrodiagnostic techniques may help in surgical indication. Surgery is often unnecessary since recovery usually occurs with conservative treatment. A difficult decision is required on timing of surgery since literature recommendations are not evidence-based.
    LO SCALPELLO-OTODI Educational 04/2012; 25(1):21-24.
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    Article: Surgical treatment of acute fingernail injuries.
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    ABSTRACT: 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.
    Journal of Orthopaedics and Traumatology 10/2011; 13(2):57-62.
  • Article: Experimental and clinical employment of end-to-side coaptation: our experience.
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    ABSTRACT: 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.
    Acta neurochirurgica. Supplement 01/2011; 108:241-5.
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    Article: Limits of reconstruction in mangled hands.
    Chirurgie de la Main 09/2010; 29(4):280-2. · 0.53 Impact Factor
  • Article: Standardized crush injury of the mouse median nerve.
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    ABSTRACT: The employment of transgenic mouse models for peripheral nerve regeneration studies is continuously increasing. In this paper, we describe a standardized method for inducing a crush lesion in mouse median nerve using a non-serrated clamp exerting a crush compression force of 20.43 MPa for a duration of 30 s. Quantitative assessment of posttraumatic functional recovery by grasping test showed that recovery was very fast and mice returned to baseline performance already after 20 days only. Stereological analysis of nerve fibers distal to the crush lesion showed the presence of axons with a significantly smaller size and thinner myelin sheath in comparison to controls. This experimental nerve injury model is highly reproducible and the impact on animal well-being is minimal. Its employment can be particularly indicated for exploring the basic neurobiological mechanisms of peripheral nerve regeneration.
    Journal of neuroscience methods 04/2010; 188(1):71-5. · 2.30 Impact Factor
  • Article: Termino-lateral nerve suture in lesions of the digital nerves: clinical experience and literature review.
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    ABSTRACT: 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.
    The Journal of hand surgery, European volume. 09/2009; 35(2):109-14.
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    Article: End-to-side nerve suture in traumatic injuries of brachial plexus: review of the literature and personal case series.
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    ABSTRACT: 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.
    The Journal of hand surgery, European volume. 08/2009; 34(5):656-9.
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    Article: Functional and morphological assessment of a standardized crush injury of the rat median nerve.
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    ABSTRACT: 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.
    Journal of neuroscience methods 05/2009; 179(1):51-7. · 2.30 Impact Factor
  • Article: A simple sterile polypropylene fingernail substitute.
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    ABSTRACT: Traumatic nail injuries are often observed in clinical practice. Usually the fingernail can be preserved, cleaned and disinfected in order to use it in the reconstructive procedure. However, in some cases the nail can be avulsed and lost or too damaged to be used. In cases when the nail is not available it should be replaced by a substitute in order to protect nail bed and avoid adherences along the proximal nail bed and the nail fold. Furthermore the substitute serves to protect the tender nail bed from painful stimuli during the healing process. We used, as fingernail substitute, a polypropylene sheet in eight patients with fingernail avulsion or disruption. The polypropylene foil was trimmed reproducing the profile of the avulsed fingernail and thinned at the proximal edge to reduce thickness in order to ease the insertion into the nail fold. A small hole was then created in the center of the foil to allow blood drainage. The substitute was usually removed one month after the application. In our clinical experience we had not complications related to the polypropylene device. The new fingernail had good cosmetic appearance in most cases and all the patients reported a good protection of the fingertip during the healing period. The substitute used in this series is sterile, inexpensive and easily available in emergency and elective operatory theater. This polypropylene foil is flexible and can be shaped and adapted to the nail curvature radius. The substitute used in our clinical series protected the nail bed during healing until the growth of the new fingernail and respected our functional expectations.
    Chirurgie de la Main 05/2009; 28(3):143-5. · 0.53 Impact Factor
  • Article: Chondrosarcoma in the distal phalanx of index finger: clinical report and literature review.
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    ABSTRACT: 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.
    Chirurgie de la Main 04/2009; 28(4):265-9. · 0.53 Impact Factor
  • Article: Employment of the mouse median nerve model for the experimental assessment of peripheral nerve regeneration.
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    ABSTRACT: The experimental investigation of nerve regeneration after microsurgical repair is usually carried out in rats, rather than mice, because of the larger sized peripheral nerves. Today however, the availability of genetically modified mice makes the use of this laboratory animal very intriguing for investigating nerve regeneration at a molecular level. In this study we aimed to provide a standardization of the experimental model based on microsurgical direct repair, by 12/0 suture, of the left median nerve in adult male mice. Postoperative recovery was regularly assessed by the grasping test. At day-75 postoperative, regenerated median nerve fibers were analyzed by design-based quantitative morphology and electron microscopy. Yet, sections were immuno-labelled using two axonal antibodies commonly employed for rat nerve fibers. Results indicated that functional recovery begun at day-15 and progressively increased reaching values not significantly different from normal by day-50. Quantitative morphology showed that, at day-75, the number of regenerated nerve fibers was not significantly different in comparison to controls. In contrast, differences were detected in fiber density, mean axon and fiber diameter and myelin thickness which were all significantly lower than controls. Immunohistochemistry showed that axonal markers commonly used for rat nerves studies are effective also for mouse nerves. Similar to the rat, the mouse median nerve model is superior to sciatic nerve model for the minimal impact on animal well-being and the effectiveness of the grasping test for motor function evaluation. The main limitation is the small nerve size which requires advanced microsurgical skills for performing 12/0 epineurial suturing.
    Journal of Neuroscience Methods 04/2008; 169(1):119-27. · 1.98 Impact Factor
  • Article: Lack of topographic specificity in nerve fiber regeneration of rat forelimb mixed nerves.
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    ABSTRACT: 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.
    Neuroscience 03/2007; 144(3):985-90. · 3.38 Impact Factor
  • Article: The European Microsurgical Research Association.
    Microsurgery 02/2007; 27(5):357-9. · 1.61 Impact Factor
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    Article: Comparison of fresh and predegenerated muscle-vein-combined guides for the repair of rat median nerve.
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    ABSTRACT: Over the last 10 years, we have investigated a particular type of bioengineered nerve guide, the muscle-vein-combined tube, which is made by filling a vein with skeletal muscle. In our previous studies we have always used fresh skeletal muscle to fill vein conduits. In the present study we compared the use of fresh and predegenerated (freeze-thawed) skeletal muscle for muscle-vein-combined nerve guides. In this study, a 10-mm-long rat median nerve defect was repaired using either type of nerve guide. The samples were analyzed 5 and 30 days after surgery by light and electron microscopy. In addition, reverse transcription polymerase chain reaction (RT-PCR) was carried out to investigate the expression of mRNAs coding for glial markers, as well as glial growth factor (NRG1) and its receptors (erbB2 and erbB3). Results showed differences between the two types of nerve guides at postoperative day 5; however, no difference was detected at day 30 suggesting that both types of tissue-engineered conduit are effective for repairing peripheral nerve defects in this experimental model.
    Microsurgery 02/2007; 27(1):48-55. · 1.61 Impact Factor
  • Article: Nerve regeneration along bioengineered scaffolds.
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    ABSTRACT: Tissue engineering has recently seen great advancements in many medical fields, including peripheral nerve reconstruction. In the rat median nerve model, we investigated nerve repair by means of bioengineered tissue scaffolds (muscle-vein-combined tubes) focusing on changes in the neuregulin-1/ErbB-receptor system which represents one of the main regulatory systems of axo-glial interaction in peripheral nerves. Repaired nerves were withdrawn at 5, 15, and 30 days postoperative and processed for morphological and retro-transcriptase polymerase chain reaction (RT-PCR) analysis. Results revealed an early and progressive increase in the expression of NRG1alpha isoform only, while the appearance of the beta isoform of NRG1, which is normally present in peripheral nerves, was delayed. In regards to ErbB2 and ErbB3 receptors, their expression increased progressively inside the muscle-vein-combined scaffolds, though with different kinetics. Taken together, these results suggest that variations in neuregulin-1/ErbB system activation play a key role in peripheral nerve regeneration along bioengineered muscle-vein-combined scaffolds. Since similar variations are also detectable in denervated skeletal muscles, it can be hypothesized that the existence of a NRG1's autocrine/paracrine trophic loop shared by both glial and muscle fibers could be responsible for the effectiveness of muscle-vein-combined conduits for repairing nerve defects.
    Microsurgery 02/2007; 27(5):429-38. · 1.61 Impact Factor
  • Article: Alternative techniques for peripheral nerve repair: conduits and end-to-side neurorrhaphy.
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    ABSTRACT: Nowadays new techniques may help the surgeon in difficult cases of nerve tissue loss: when a gap is produced in a mixed nerve, the use of conduits can be an alternative to nerve grafts, which still represent the "gold standard" for this kind of lesions. We have applied biologic conduits (muscle inside a vein) in more than 40 cases since 1993 with 85% of good functional results for both sensory and mixed nerves up to 5 cm. The advantages of this technique are: (1) all graft material is easily withdrawn in the lesion area and thus is not necessary to perform any new incision; (2) the possibility of reconstructing nerve gaps up to 5 cm avoids secondary damage created by the withdrawal of healthy nerves; (3) the possibility for spontaneous orientation of regenerating nerve fibers is offered as fibers are allowed to search for their final target (chemiotropism). Furthermore, when the tissue loss is important or the proximal nerve stump is not available, so jeopardizing the possibility of recovery with traditional reconstruction, the use of end-to-side neurorrhaphy has been described to solve the problem. However the use of end-to-side neurorrhaphy in the clinical setting for motor recovery remains controversial. In our experience we had satisfying results only in 20% of cases and thus motor reconstruction in the absence of an available proximal nerve may be best handled by nerve to nerve transfers. By contrast we had good results in sensory nerve reconstruction (especially digital nerves) by end-to-side coaptation.
    Acta neurochirurgica. Supplement 02/2007; 100:43-50.
  • Article: Functional, morphological and biomolecular assessment of posttraumatic neuro-muscular recovery in the rat forelimb model.
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    ABSTRACT: 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.
    Acta neurochirurgica. Supplement 02/2007; 100:173-7.
  • Article: Origin and history of end-to-side neurorrhaphy.
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    ABSTRACT: 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.
    Microsurgery 02/2007; 27(1):56-61. · 1.61 Impact Factor
  • Article: Low-power laser biostimulation enhances nerve repair after end-to-side neurorrhaphy: a double-blind randomized study in the rat median nerve model.
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    ABSTRACT: Previous studies have shown that low-power laser biostimulation (lasertherapy) promotes posttraumatic nerve regeneration. The objective of the present study was to investigate the effects of postoperative lasertherapy on nerve regeneration after end-to-side neurorrhaphy, an innovative technique for peripheral nerve repair. After complete transection, the left median nerve was repaired by end-to-side neurorrhaphy on the ulnar "donor" nerve. The animals were then divided into four groups: one placebo group, and three laser-treated groups that received lasertherapy three times a week for 3 weeks starting from postoperative day 1. Three different types of laser emission were used: continuous (808 nm), pulsed (905 nm), and a combination of the two. Functional testing was carried out every 2 weeks after surgery by means of the grasping test. At the time of withdrawal 16 weeks postoperatively, muscle mass recovery was assessed by weighing the muscles innervated by the median nerve. Finally, the repaired nerves were withdrawn, embedded in resin and analyzed by light and electron microscopy. Results showed that laser biostimulation induces: (1) a statistically significant faster recovery of the lesioned function; (2) a statistically significant faster recovery of muscle mass; (3) a statistically significant faster myelination of the regenerated nerve fibers. From comparison of the three different types of laser emissions, it turned out that the best functional outcome was obtained by means of pulsed-continuous-combined laser biostimulation. Taken together, the results of the present study confirm previous experimental data on the effectiveness of lasertherapy for the promotion of peripheral nerve regeneration and suggest that early postoperative lasertherapy should be considered as a very promising physiotherapeutic tool for rehabilitation after end-to-side neurorrhaphy.
    Lasers in Medical Science 02/2004; 19(1):57-65. · 2.00 Impact Factor