La réparation de pertes de substance des nerves digitaux avec la technique de la greffe veineuse plus interposition de tissu nerveux. Étude prospective et randomisée

Treatment options for digital nerve injury: a systematic review and meta-analysis

BACKGROUND

Surgical treatment of finger nerve injury is common for hand trauma. However, there are various surgical options with different functional outcomes. The aims of this study are to compare the outcomes of various finger nerve surgeries and to identify factors associated with the postsurgical outcomes via a systematic review and meta-analysis.

METHODS

The literature related to digital nerve repairs were retrieved comprehensively by searching the online databases of PubMed from January 1, 1965, to August 31, 2021. Data extraction, assessment of bias risk and the quality evaluation were then performed. Meta-analysis was performed using the postoperative static 2-point discrimination (S2PD) value, moving 2-point discrimination (M2PD) value, and Semmes-Weinstein monofilament testing (SWMF) good rate, modified Highet classification of nerve recovery good rate. Statistical analysis was performed using the R (V.3.6.3) software. The random effects model was used for the analysis. A systematic review was also performed on the other influencing factors especially the type of injury and postoperative complications of digital nerve repair.

RESULTS

Sixty-six studies with 2446 cases were included in this study. The polyglycolic acid conduit group has the best S2PD value (6.71 mm), while the neurorrhaphy group has the best M2PD value (4.91 mm). End-to-side coaptation has the highest modified Highet's scoring (98%), and autologous nerve graft has the highest SWMF (91%). Age, the size of the gap, and the type of injury were factors that may affect recovery. The type of injury has an impact on the postoperative outcome of neurorrhaphy. Complications reported in the studies were mainly neuroma, cold sensitivity, paresthesia, postoperative infection, and pain.

CONCLUSION

Our study demonstrated that the results of surgical treatment of digital nerve injury are generally satisfactory; however, no nerve repair method has absolute advantages. When choosing a surgical approach to repair finger nerve injury, we must comprehensively consider various factors, especially the gap size of the nerve defect, and postoperative complications. Type of study/level of evidence Therapeutic IV.

Comparison of nerve conduits and nerve graft in digital nerve regeneration: A systematic review and meta-analysis

The goal of this systematic review and meta-analysis was to compare nerve conduits and nerve graft for peripheral nerve regeneration. This type of lesion frequently causes disability due to pain, paresthesia and motor deficit. On the PICO process, "P" corresponded to patients with peripheral digital nerve lesions of any age, gender or ethnicity, "I" to interventions with nerve conduits or nerve graft, "C" to the control group with no treatment, placebo or receiving other treatment, and "O" to outcome assessment of nerve regeneration. Initial search found in 3859 studies, including 2001 duplicates. The remaining 1858 studies were selected by title and/or abstract; 1798 articles were excluded, leaving 60 articles for full-text review. Thirty-nine of these 60 reports were excluded as not meeting our inclusion criteria, and 21 articles were ultimately included in the systematic review. For patients older than 40 years, there was a greater mean improvement on S2PD and M2PD tests with grafting, which seemed to be the better surgical technique, positively impacting prognosis. On the M2PD test, there was significantly greater improvement in 11-17.99 mm defects with grafting (P < 0.001); this finding should guide surgical strategy in peripheral nerve regeneration, to ensure better outcomes.

Immediate or Delayed Transplantation of a Vein Conduit Filled with Nasal Olfactory Stem Cells Improves Locomotion and Axogenesis in Rats after a Peroneal Nerve Loss of Substance

Over the recent years, several methods have been experienced to repair injured peripheral nerves. Among investigated strategies, the use of natural or synthetic conduits was validated for clinical application. In this study, we assessed the therapeutic potential of vein guides, transplanted immediately or two weeks after a peroneal nerve injury and filled with olfactory ecto-mesenchymal stem cells (OEMSC). Rats were randomly allocated to five groups. A3 mm peroneal nerve loss was bridged, acutely or chronically, with a 1 cm long femoral vein and with/without OEMSCs. These four groups were compared to unoperated rats (Control group). OEMSCs were purified from male olfactory mucosae and grafted into female hosts. Three months after surgery, nerve repair was analyzed by measuring locomotor function, mechanical muscle properties, muscle mass, axon number, and myelination. We observed that stem cells significantly (i) increased locomotor recovery, (ii) partially maintained the contractile phenotype of the target muscle, and (iii) augmented the number of growing axons. OEMSCs remained in the nerve and did not migrate in other organs. These results open the way for a phase I/IIa clinical trial based on the autologous engraftment of OEMSCs in patients with a nerve injury, especially those with neglected wounds.

Nerve conduits for treating peripheral nerve injuries: A systematic literature review

Peripheral nerve injuries are a major public health problem. Nerve conduits have been developed in the recent years, although it is still not clear if they should replace nerve grafting and neurorrhaphy. This systematic review aims to gather evidence regarding the use of nerve conduits for peripheral nerve repair. The following electronic databases were searched: MEDLINE, Cochrane Library (CENTRAL) and Embase. Study selection and data extraction followed the PRISMA guidelines. The systematic review of the literature retrieved 6767 articles. Only 27 studies were retained accounting for 1022 patients: 10 randomized controlled trials, 15 case series and 2 cohort studies. Ten different types of tubes were described and a variety of evaluation methods were used to assess outcomes in terms of efficacy (motor and sensory recovery) and complications. The Semmes-Weinstein monofilament test and the static and moving 2-point discrimination test were the most commonly applied tests to evaluate nerve recovery. In general, outcomes showed no significant difference between groups. Synthetic conduits had more complications. Despite major methodological limitations in the studies, we can conclude that use of nerve conduits is preferable over suture repair and nerve grafting, as the functional recovery rates are above 80%. The choice of conduit is based on the surgeon's expertise, but use of synthetic conduits is discouraged due to their higher complication rates.

Thoracic sympathetic nerve reconstruction for compensatory hyperhidrosis: the Melbourne technique

BACKGROUND

Compensatory hyperhidrosis (CH) is a potential complication following endoscopic thoracic sympathectomy (ETS) in the management of primary hyperhidrosis. CH is considered a permanent condition with significant psychosocial impacts but with few treatment options. Various reversal surgical techniques, aimed at reconstituting sympathetic pathways, have been developed but results have been inconsistent.

OBJECTIVE

We present two case reports of a novel technique of reversal surgery, the Melbourne technique, which was employed to treat severe CH that developed within 3-5 months following ETS. Both patients were followed-up to 8 years.

METHODS

The Melbourne technique employs an endoscopic approach to expose previously sympathectomized or sympathotomized thoracic sympathetic chains. In these two cases it was performed on the right side only. Instead of an interpositional nerve graft, an autogenous vein graft was simultaneously harvested and used as a nerve conduit to bridge the secondary nerve defect after neuroma excision. Long-term outcomes were assessed using the dermatology life quality index (DLQI) and the quality of life (QoL) questionnaires, which are validated for hyperhidrosis.

RESULTS

In both cases, patients reported postoperative improvements in QoL scores. However, the improvement was more marked in one case compared with the other. There were no significant immediate and long-term postoperative complications.

CONCLUSIONS

The Melbourne technique shows promise as an alternative to interpositional nerve grafts or nerve transfers employed in other endoscopic reversal surgeries for CH.

Evaluation of emergency nerve grafting for proper palmar digital nerve defects: a retrospective single centre study

HYPOTHESIS

Finger trauma often results in discontinuity of the proper palmar digital nerves. The goal of this study was to retrospectively evaluate the clinical outcomes of emergency nerve grafting and the resulting donor site morbidity.

MATERIAL AND METHOD

Three women and 13 men who had been operated between 2008 and 2012 were reviewed. The average patient age was 39 years (range 18-78). All were operated on an emergency basis. The average defect was 38 mm long (range 15-60). The nerves were harvested from four sites: lateral antebrachial cutaneous nerve (12 cases), banked finger (2 cases), terminal portion of posterior interosseous nerve (1 case) and anterior interosseous nerve (1 case). The evaluation consisted of patient questioning and clinical examination of the treated finger and donor site. An objective sensory exam was also performed. The results were expressed according to the British Medical Research Council (MRC) classification.

RESULTS

There was little donor site morbidity (2 cases of symptomatic hypoesthesia, 1 case of scar hypersensitivity). Sixty-nine percent of patients stated that their grafted finger did not cause them any trouble during activities of daily living. Three patients required job retraining. Pain in the grafted finger was 0.6 (range 0-5) on the VAS. Normal sensation was restored in 31% of cases based on the monofilament sensory test; 25% had a slight decrease in touch sensitivity and 25% had reduced protective sensations. Weber's two-point discrimination test found 50% normal sensibility (threshold<6mm) and 6% with mediocre sensibility (threshold of 6-10mm). On the MRC grading scale, 50% of patients were at S4, 6% at S3+, 19% at S3, 12% at S2 and 12% at S1.

CONCLUSION

There were 56% good results in this patient series (S3+/S4) and no patients at S0. Donor site morbidity was rare. Thus use of nerve grafting is still a relevant option in an emergency setting.

LEVEL OF EVIDENCE

Level IV.

Clinical applications of autografts, conduits, and allografts in repair of nerve defects in the hand: current guidelines

Traumatic nerve injuries are common conditions treated by hand surgeons, and the optimal treatment of a severed nerve requires providing a healthy wound bed, generous trimming to healthy nerve substance, and a minimal-tension approximation. The gold standard for repair of a critical nerve gap has been the nerve autograft. However, results are generally less favorable than direct suture. Autogenous and synthetic conduits and processed nerve allografts have been developed as less morbid and more convenient alternatives to autografts, but the reported outcomes have been uneven. Engineered neural tissues show great promise in inducing nerve regeneration across a gap.

Sensory reinnervation of muscle spindles after repair of tibial nerve defects using autogenous vein grafts

Motor reinnervation after repair of tibial nerve defects using autologous vein grafts in rats has previously been reported, but sensory reinnervation after the same repair has not been fully investigated. In this study, partial sensory reinnervation of muscle spindles was observed after repair of 10-mm left tibial nerve defects using autologous vein grafts with end-to-end anastomosis in rats, and functional recovery was confirmed by electrophysiological studies. There were no significant differences in the number, size, or electrophysiological function of reinnervated muscle spindles between the two experimental groups. These findings suggest that repair of short nerve defects with autologous vein grafts provides comparable results to immediate end-to-end anastomosis in terms of sensory reinnervation of muscle spindles.

The incidence of symptomatic neuroma in amputation and neurorrhaphy patients

PURPOSE

The incidence of symptomatic neuroma in finger nerve injuries varies widely in the literature. In this retrospective study, we evaluated the incidence of symptomatic neuroma after repair of digital nerve injuries (neurorrhaphy) and after amputation of one or more fingers. We also determined the need for re-operation on symptomatic neuroma patients.

METHODS

In a retrospective study, we collected data from medical files. All patients who were treated for a hand trauma in the emergency department during the last 10 years were included. We gathered data on the presence of symptomatic neuroma and re-operation of the patients.

RESULTS

In our database, 583 people had a peripheral nerve injury of whom 177 people had an amputation. The incidence of digital nerve injury without amputation followed by neurorrhaphy was 1%. In digital nerve injuries with amputation the incidence was 7.8%, which is significantly higher than after digital nerve injuries without amputation.

CONCLUSIONS

People with an amputation injury have significantly more symptomatic neuroma than people who undergo neurorrhaphy. People who have a symptomatic neuroma after digital nerve injuries have been operated significantly more than people who have a non-symptomatic neuroma or no neuroma at all. This information can be of help when treating digital nerve injuries. TYPE OF STUDY/LEVEL OF EVIDENCE (LOE): Prognostic.

Vein conduit associated with microsurgical suture for complete collateral digital nerve severance

The aim of this study is to present the long term results of a series of 53 vein conduit grafts as first line therapy to repair complete severance of one or more collateral digital nerves. The surgical technique included an epi-perineural suture of the nerve under minimal tension, associated with a vein graft harvested from the back of the hand to cover the nerve. None of the patients presented with a neuroma, spontaneous pain or had stopped using the injured finger. Sensibility results were good or very good in 67% of cases. The scar at the donor site was very light or invisible. A total of 96% of patients were satisfied or very satisfied. This simple technique, by protecting the injured nerve, results in a rate of sensory nerve recovery that is comparable or better than that of other series in the literature, without neuroma and with minimal scarring at the donor site.

Clinical application of inside-out vein grafts for the treatment of sensory nerve segmental defect

PURPOSE

The gold standard for the treatment of segmental nerve defect is an autogenous nerve graft. However, donor site morbidity is an inevitable complication. We substituted an autogenous nerve graft with an inside-out vein graft for the treatment of segmental sensory nerve defect and the clinical results were evaluated retrospectively.

PATIENTS AND METHODS

Eleven patients of sensory nerve defects have undertaken inside-out vein grafts for the recovery of sensation. The involved nerves were digital nerves in three cases, peroneal nerves in two cases, saphenous nerve in two cases, and superficial radial nerves in four cases. The average length of defects was 2.71 cm (1-6 cm). Donor veins were harvested 4 mm longer than nerve defects and everted to promote nerve regeneration. Patients' objective satisfactions and two-point discriminations were determined, the Semmes-Weinstein monofilament test was performed, and British Medical Council sensory functional scores were evaluated.

RESULTS

Sensory functional scores recovered to over S3 in all cases. No donor site morbidity was caused by vein harvesting, and all patients achieved satisfactory results with protective sensation at involved sites.

CONCLUSION

The inside-out vein graft offers a good surgical alternative to an autogenous nerve graft for the reconstruction of sensory nerve defects without donor site morbidity.

[Retrospective monocentric comparative evaluation by sifting of vein grafts versus nerve grafts in palmar digital nerves defects. Report of 32 cases]

AIM

Palmar digital nerves defects can be treated by conventional nerve grafts or by means of a conduit, such as a vein. We compared a vein graft technique to a nerve graft technique in a retrospective monocentric study.

MATERIAL AND METHOD

A surgeon who was not involved in the treatment reviewed blind 15 nerve grafts and 17 vein grafts. The evaluation concerned sensitivity, pain, donor site morbidity, social integration and autoassessment of the benefits by the patient. Data were compacted by a sifting method eliminating bad results. The classical functional scores (British Medical Research Council, Möberg, Chanson, Alnot, Dumontier) were also used.

RESULTS

The evaluation was carried out at least 11 months after treatment. Defect was never greater than 30 mm. After sifting, vein grafts appeared less efficient than nerve grafts (41% good results against 73%), except in emergencies (86% good results).

CONCLUSION

For defect loss of no more than 30 mm in emergencies, the authors propose to use vein grafting. In other situations, the surgeon must take into account the patient's profile and the hemi-pulp concerned, dominant or non-dominant, before opting for a nerve or a vein graft.

Secondary nerve reconstruction using vein conduit grafts for neglected digital nerve injuries

Digital nerve defects can result from neglected nerve injuries. The standard method of reconstruction is nerve grafting, but donor-site morbidity encourages searching for alternative graft materials, including vein conduit grafts. From 1995-2005, three patients with neglected digital nerve injuries received vein conduit grafting for digital nerve reconstruction in our hospital. The interval between the injury and the reconstructive procedure ranged from 17 days to 2 years, and the length of the defects ranged from 0.8 to 2.5 cm. All the vein grafts were harvested from the distal forearm. Patient 1 had a moving and a static two-point discrimination (M2PD and S2PD) of 3 and 4 mm, respectively, at a 12-year follow-up. Patient 2 had an M2PD of 5 mm and S2PD of 6 mm at an 11-year follow-up, and the patient 3 had both an M2PD and S2PD of 4 mm at a near 3-year follow-up. They all achieved useful sensory function (S3 and S3+) by modified Highet and Sander criteria. Although previous studies showed secondary repair using vein grafts yielded worse sensory recovery than that of primary repair, in our cases, secondary digital nerve reconstruction with vein conduit grafts gives excellent results at the long-term sensory evaluation, two of them with more than 10 years' follow-up. To the best of our knowledge, this might be the longest follow-up after secondary digital nerve reconstruction using a vein conduit graft. It bears the advantages of readily accessible, no donor-site morbidity, and compatible in size with digital nerves.