Types Of Nerve Repair Research Articles

The Effect of Surgical Timing on Upper Extremity Nerve Repair.

The purpose of this study was to evaluate the association between timing of nerve repair and the ability to perform a primary nerve repair versus a bridge repair requiring the use of allograft, autograft, or a conduit in lacerated upper extremity peripheral nerve injuries. This is a retrospective case-control study of patients who underwent upper extremity nerve repair for lacerated peripheral nerves identified by Current Procedural Terminology codes. Timing of injury and surgery, as well as other information such as demographic information, mechanism of injury, site of injury, and type of nerve repair, was recorded. The odds of a patient requiring bridge repair based on the duration of time between injury and surgery was evaluated using logistic regression. A total of 403 nerves in 335 patients (mean age 35.87 ± 15.33 years) were included. In all, 241 nerves were primarily repaired and 162 required bridge repair. Patients requiring bridge repair had a greater duration between injury and surgery compared with patients who underwent primary repair. Furthermore, the nerves requiring bridge repair were associated with a greater gap compared with the nerves repaired primarily. Based on logistic regression, each 1-day increase in duration between injury and surgery was associated with a 3% increase in the odds of requiring bridge repair. There is no defined critical window to achieve a primary nerve repair following injury. This study demonstrated that nerve injuries requiring bridge repair were associated with a significantly greater delay to surgery.

Peripheral Neurectomy With Customized Nerve Reconstruction for Periorbital Neuropathic Pain: Initial Experience and Clinical Outcomes.

To describe a novel, minimally invasive surgical technique to treat severe, intractable periorbital neuropathic pain. A retrospective analysis of patients with severe, treatment-refractory periorbital pain who underwent transection of affected sensory trigeminal branches with nerve repair was performed. Collected data included etiology and duration of neuropathic pain, comorbidities, prior treatment history, surgical technique including site of transected sensory nerves and type of nerve repair, preoperative and postoperative pain scores as well as follow-up duration. Differences between preoperative and postoperative values were analyzed by the Wilcoxon signed-rank test. A total of 5 patients with severe periorbital neuropathic pain underwent transection of affected supraorbital, supratrochlear, infratrochlear, infraorbital, zygomaticotemporal, and zygomaticofacial nerves with customized nerve reconstruction. All 5 had improvement of periorbital pain after surgery, with 3 (60%) noting complete resolution of pain and 2 (40%) experiencing partial pain relief over a median follow-up period of 9 months (interquartile range [IQR], 6-19 months). Of the 3 patients who had complete resolution of pain, all reported continued pain relief. Median McGill pain scores significantly decreased from 8.4 (IQR, 8.2-10.0) preoperatively to 0.0 (IQR, 0.0-4.8; p < 0.001) postoperatively. All patients reported satisfaction with the surgical procedure and stated that they would undergo the procedure again if given the option. One patient with history of postherpetic neuralgia (PHN) had reactivation of herpes zoster at postoperative month 3, which was self-limited, without worsening of her neuropathic pain. Another patient with PHN required a staged procedure to achieve complete pain relief. Peripheral neurectomy with customized reconstruction of involved sensory nerves can successfully reduce and even eradicate periorbital neuropathic pain that was previously recalcitrant to combination pharmacotherapy and prior neurolysis procedures.

English

BACKGROUND Peripheral nerve injuries (PNIs) often accompany trauma to limbs and is a major cause of morbidity. Various surgical techniques are described for nerve repair and various factors influence the functional outcome after repair. This study intends to assess the functional outcome following PNI repair and various factors affecting the final outcome post repair. In this study we wanted to assess the functional outcome of PNI repair done at our institute. METHODS This is a prospective observational study conducted at the Department of Plastic and Reconstructive Surgery, Government Medical College, Thiruvananthapuram, India, from September 2017 to September 2019 (24 months) in patients with a diagnosis of traumatic peripheral nerve injury. Data collected were analysed by statistical programme for social sciences (SPSS) version 20. Quantitative variables were expressed in mean &amp; standard deviation (SD) and qualitative variables were expressed in proportions. Associations were tested by chi-square test. RESULTS A total of 100 patients were studied. Overall satisfactory sensory outcome was found to be 45.2% in median nerve and 45.5 % in ulnar nerve injuries (P value - 0.492). Overall satisfactory motor outcome was found to be 45.2 % in median nerve and 36.3 % in ulnar nerve injuries (P value - 0.391). Age &lt; 40 years was found to be significantly associated with a good sensory and motor recovery. Diabetes mellitus was associated with a poor sensory and motor outcome compared to patients without any comorbidities. Use of nerve grafts was associated with less sensory recovery compared to primary nerve coaptation (P value - 0.496). Nerve repairs done between 4 - 7 days of injury had better sensory and motor outcome. CONCLUSIONS Traumatic peripheral nerve repair has a variable functional outcome and is dependent on various factors like age and other patient related factors, mechanism of injury and the type of nerve repair. Accurate diagnosis, attention to detail and timely intervention can improve the overall functional outcome. KEYWORDS Peripheral Nerve Injury, Nerve Repair, Functional Outcome

Trends in Peripheral Nerve Epidemiology and Reconstruction: A State Database Study of Direct Repairs, Grafts, and Conduits.

Peripheral nerve injuries (PNIs) are most commonly treated with direct nerve repair procedures or nerve autografts. However, recent advancements in synthetic and vein conduits have led to their increased utilization. The present study quantifies the incidence of these procedures over time and geography and identifies differences in complication rates, illustrating the current epidemiologic climate regarding conduit use for PNI repair. A query was conducted using the State Ambulatory Surgery and Services Databases data from 2006 to 2011 in both Florida and California for patients undergoing nerve repair, nerve grafting, synthetic conduits, and vein conduits. Patient zip code data were analyzed to determine the geographic distribution of various types of repair. In addition, text-mining algorithms were used to identify trends in PNI-related publications. In the 6-year period investigated, direct nerve repair was the most frequently used procedure for PNIs. However, the utilization of direct repairs declined significantly from 2006 to 2011. Synthetic and vein conduits demonstrated a significant increase over the same period. There were significantly higher rates of complications for autologous grafts (3.3%), vein conduits (3.5%), and synthetic conduits (2.4%), as compared with direct nerve repairs (1.4%). There was a nonsignificant difference in infection rates between these types of nerve repair. From an epidemiologic perspective, both graft and synthetic conduit-based PNI repairs are increasing in prevalence both in clinical practice and in the academic literature. This will likely continue in the future with the development of advancements in biologic and synthetic nerve conduit PNI repair options.

Recovery and Regrowth After Nerve Repair: A Systematic Analysis of Four Repair Techniques

BackgroundOutcome assessments that evaluate post-transection nerve repair do not often correlate with one another. The aims of this study were twofold: to compare four nerve repair techniques with each other and incorporate both negative and positive control groups and to identify possible correlations between outcome assessments. Materials and methodsSciatic nerve transection and repair was performed in Lewis rats using one of the following techniques: interrupted epineural, running epineural, grouped fascicular, epineural with absorbable type I collagen wrap, and high tension for incorporation of a negative control. A sham surgery group was also included as a positive control group. Outcomes were compared using assessments of functional recovery (behavior and electrophysiology) and nerve regrowth (imaging and histomorphometry). Three-dimensional printed custom electrode stabilization and imaging devices were designed and fabricated to provide standardization in assessment between subjects. ResultsNerve repair was performed in 48 male Lewis rats. In all animals, functional testing was performed at week 13. The sham group (n = 7) performed the best on both behavioral assays (P < 0.001) and electrophysiology assessments (P < 0.001). The negative control group (high tension) performed poorest on multiple assessments, and there were no significant differences observed for any of the four repair types. Positive correlations were observed between behavioral and histomorphometric tests. ConclusionsThere was no difference in outcome between the four types of nerve repair. High-tension nerve repair represents an ideal negative control. Not all assessment methods correlate equally, and consistent use of complimentary outcome assessments could allow for improved comparison between studies.

Retrospective Study of Surgical Repair of Gunshot Injuries of Peripheral Nerves.

Background: Shotgun injuries of the peripheral nerves are presented frequently during the last decades at the Service of Neurosurgery of UHC “Mother Theresa” in Tirana. In such cases the surgical repair of brachial plexus and peripheral nerves constitutes a challenge with relation to difficulties related with mechanism of injury, coexistence of other vascular damage, bone, soft tissue and visceral lesions.&#x0D; Materials and methods: A retrospective study of operated cases with shotgun injuries treated in our Department from 1997 to 2012 was conducted getting information from clinical charts, surgical registries, intraoperative photos and videos of the surgical repair of peripheral nerves. We performed a thorough analysis of the most influencing factors of surgical outcome such as: age, severity of injury, site of injury with relation to the innervated muscles, type of necessary nerve repair, presence of causalgia before operation, concomitant compromise of vascularization and/or locomotor apparatus. Follow-up of the patient was conducted through out-patient visits and phone interviews going back 10 years from surgical repair.&#x0D; Results: 68 cases operated for shotgun injury of brachial plexus or peripheral nerves were revised. There were different ages and both sexes involved. The type of nerve repair went from interfascicular neurolysis to direct end-to-end microsuture and nerve grafting. Timely repair of the nerve injury proved to be yielding better result than late repair in terms of pain relief and sensory motor improvement of the preoperative neurological deficit. The degree and the quality of improvement after surgery is related to the type of repair (neurolysis improves better and faster than grafting), the distance from site of injury to the effector muscle (the longer the distance more time it takes for the function to recover). The recovery of the brachial plexus was followed up for many years and further surgery proved to be necessary and of further improvement.&#x0D; Conclusions: From our long term experience dealing with surgical repair of shotgun injury of peripheral nerves we have learnt that early surgical repair is more efficacious in treating pain and gives better results in terms of motor and sensitive recovery than six months after injury as it was usually done. Long term follow-up is necessary to help with further surgery in case of distal decompressive surgery in anatomical tunnels.

Epidemiological Study of 1368 Cases of Surgical Repair for Traumatic Peripheral Nerve Injury.

Traumatic injury of the peripheral nerves should be treated in specialized centres. This study presents the epidemiological data of 1368 consecutive patients operated for peripheral nerve injuries beside the Service of neurosurgery, Department of Neurosciences, UHC "Mother Theresa", Tirana. In order to obtain the necessary data for this study we revised the clinical records, surgical registers and pre, intra and postoperative photo/video of the cases operated for peripheral nervous system injuries. A data recording program of the surgery cases was built ad hoc, categorizing the cases according to several variables. The data collected from the operated cases were manually inserted to be processed by the program. Results of informatics elaboration of the data were obtained, reviewed and categorized by: age, gender, type of trauma, localization of injury and type of nerve repair. Future studies to be conducted in this field will focus in determining the level of nerve injury, time from the injury to intervention, distance from the site of trauma to the effector organ. The data will build necessary information for data mining, which based on these important factors that influence the result of nerve repair, will be useful for the prediction of the result in new patients harbouring peripheral nerve injury before undergoing surgery.

Long-term surgical outcome of median nerve injuries

Background: Median nerve integrity is a prerequisite of normal hand function. The median nerve is a frequently injured nerve, and recent evidence indicates that nerve surgery may produce acceptable outcomes. The present study provides a framework of long-term surgical outcomes of median nerve injuries and specifies independent predictors of motor and sensory recovery. Materials and Methods: In the retrospective study, patients with median nerve injuries undergoing the nerve surgery were reviewed. Mechanism of injury, level of injury (arm, elbow/forearm, and wrist), type of injury and lesion, type of surgical repair, and the time interval from injury to surgery were assessed. The long-term follow-up of motor recovery, sensory recovery, and quality of life was done. Results: A total of 106 cases with median nerve injuries undergoing nerve surgery were included in this study. Most injuries were at wrist level with a higher frequency of sharp and not in continuity lesions. There was a significant association between the three outcomes (motor recovery, sensory recovery, and quality of life) and smoking, addiction, type of injury, type of lesion, and type of nerve repair. There was a significant correlation between quality of life and muscle force recovery and between quality of life and sensory recovery. Muscle force recovery was significantly correlated with sensory recovery. Conclusions: The findings of the present study suggest that male and young subjects, lesions in continuity, and injuries treated without grafting may show better surgical outcomes.

Remodeling of motor units after nerve regeneration studied by quantitative electromyography

ObjectivePeripheral nerve has the capacity to regenerate after nerve lesions; during reinnervation of muscle motor units are gradually reestablished. The aim of this study was to follow the time course of reestablishing and remodeling of motor units in relation to recovery of force after different types of nerve repair. MethodsReinnervation of muscle was compared clinically and electrophysiologically in complete median or ulnar nerve lesions with short gap lengths in the distal forearm repaired with a collagen nerve conduit (11 nerves) or nerve suture (10 nerves). Reestablishment of motor units was studied by quantitative EMG and recording of evoked compound muscle action potential (CMAP) during a 24-month observation period after nerve repair. ResultsForce recovered partially to about 80% of normal. Denervation activity gradually decreased during reinnervation though it was still increased at 24months. Nascent motor unit potentials (MUPs) at early reinnervation were prolonged and polyphasic. During longitudinal studies, MUPs remained prolonged and their amplitudes gradually increased markedly. Firing of MUPs was unstable throughout the study. CMAPs gradually increased and the number of motor units recovered to approximately 20% of normal. There was weak evidence of CMAP amplitude recovery after suture ahead of conduit repair but without treatment related differences at 2years. ConclusionsSurgical repair of nerve lesions with a nerve conduit or suture supported recovery of force and of motor unit reinnervation to the same extent. Changes occurred at a higher rate during early regeneration and slower after 12months but should be followed for at least 2years to assess outcome. EMG changes reflected extensive remodeling of motor units from early nascent units to a mature state with greatly enlarged units due to axonal regeneration and collateral sprouting and maturation of regenerated nerve and reinnervated muscle fibers after both types of repair. SignificanceRemodeling of motor units after peripheral nerve lesions provides the basis for better recovery of force than the number of motor axons and units. There were no differences after repair with a collagen nerve conduit and nerve suture at short nerve gap lengths. The reduced number of motor units indicates that further improvement of repair procedures and nerve environment is needed.

Early Clinical Experience With Collagen Nerve Tubes in Digital Nerve Repair

In cases of digital nerve injury in which nerve ends cannot be approximated without tension, autologous nerve grafts represent the most commonly used method for reconstruction. Recently, interest in synthetic nerve guides as an alternative to grafting has increased. Although several basic science studies have shown promise for collagen tubes, clinical studies of their success in humans are limited. The purpose of this study was to review our early clinical experience with collagen nerve tubes. The authors identified and followed all cases involving digital nerve repair at our institution over a 2-year period. Twelve patients had repair of a digital nerve with a collagen nerve tube during the study period. Two patients were lost to follow-up, and 1 patient had amputation of the grafted finger secondary to complications of other injuries. The primary outcome data points for the remaining 9 patients were the static 2-point discrimination (2PD), Semmes-Weinstein monofilament testing, and a Quick Disabilities of the Arm, Shoulder, and Hand (DASH) outcome survey at final follow-up. Nine patients had follow-up of at least 1 year, with an average follow-up time of 15 months (range 12-22 months). There were no intraoperative or postoperative complications related to the nerve tubes. Using modified American Society for Surgery of the Hand guidelines, 2PD results were good or excellent in 8 out of 9 of patients. Semmes-Weinstein testing results were full in 5 patients, diminished light touch in 2, diminished protective sensation in 1, and loss of protective sensation in 1. Average Quick DASH scores for the group were 10.86 overall, 4.86 for the work module, and 23.21 for the sports/performing arts module. Although the patients in this study are still within the early follow-up period, our initial results compare favorably with those reported in the existing literature for various types of nerve repair and reconstruction, suggesting that collagen nerve tubes might offer a clinically effective option for restoration of sensory function. Therapeutic IV.

Graft repair of the peroneal nerve restores histochemical profile after long‐term reinnervation of the rat extensor digitorum longus muscle in contrast to end‐to‐end repair

Declining motor function is a prominent feature of ageing physiology. One reason for this is a reduction in plasticity that normally compensates for ongoing reorganization of motor units under physiological conditions. Previous work from our laboratory has shown that microsurgical repair of the transected peroneal nerve is followed by considerable changes in the histochemical profile of the reinnervated extensor digitorum longus (EDL) muscle and that these changes are dependent on both the time and the type of nerve repair. At 6 months postoperatively, a trend toward reversibility could be discerned. In the present work, we analysed the long-term reorganization of histochemical motor unit distribution patterns 15 months after performing either end-to-end repair or grafting of the peroneal nerve in 3-month-old rats. In addition, the EDL muscles of an age-matched control group (age 18 months) were analysed for age-dependent changes. We observed a loss of histochemical organization of motor units leading to an additional fibre type (SDH-INT) in the control group. Fifteen months after end-to-end repair, the histochemical profile showed a decrease in fibre type IIA and an increase in fibre type SDH-INT (P < 0.05), indicating a profound histochemical disorganization of motor units. In contrast, nerve grafting largely restored the histochemical profile of reinnervated EDL muscles. Fibre type grouping was present after both types of nerve repair. These findings show that reorganization of the histochemical profile in reinnervated muscles is dependent on the time and type of nerve repair and is long lasting. In this study, grafting provided superior results compared with end-to-end repair. These long-term results after peripheral nerve repair are influenced by age-dependent changes. Accordingly, nerve repair reduces the normal functional plasticity of motor unit organization. This reduction is enhanced by increasing age.

Histochemical alterations of re‐innervated rat extensor digitorum longus muscle after end‐to‐end or graft repair: a comparative histomorphological study

Changes in the histochemical profile of 43 rat extensor digitorum longus muscles undergoing de-innervation and re-innervation were recorded. Assessment of fibre type composition and muscle fibre cross-sectional area was performed at 15, 30, 90 and 180 days post operative (p.o.) after either primary end-to-end repair or autologous graft repair of the common peroneal nerve (n = 5 per time point and type of repair). The size and histochemical profile of single muscle fibres were analysed by computer-assisted quantification on the basis of their myofibrillar ATPase (pH 4.3) and succinate dehydrogenase (SDH) activities in serial, whole-muscle cross-sections. Accordingly, four muscle-fibre types could be functionally identified: (1) slow oxidative (SO, type I); (2) fast-oxidative glycolytic (FOG, type IIA); (3) fast glycolytic (FG, type IIB); and (4) succinate dehydrogenase intermediate (SDH-INT). At 15 days following end-to-end repair, the SDH-INT muscle fibre type was observed. By contrast, 15 days following graft repair, no changes in fibre type composition were observed (vs. control). At 30 days p.o. in the group that received end-to-end repair, type SDH-INT reached its maximum and was significantly higher than in the group that underwent graft repair. At 90 days p.o., the amount of SDH-INT fibres declined after end-to-end repair, but it was still significantly higher than in the group treated with a nerve graft. The increase of the SDH-INT fibre type was mirrored by a proportional disappearance of FG and FOG fibres. These changes were time-dependent, not reversible at 180 days p.o and largely blunted after nerve graft. Muscle-fibre size decreased at 15 and 30 days after both types of nerve repair. This decrease was transient and reversible within 90 days p.o. These findings reflect the fact that the reorganization of the histochemical profile in re-innervated muscles is both time dependent and long lasting. The degree of this reorganization is significantly higher after end-to-end repair than after graft repair.

Motoneuron adaptability to new motor tasks following two types of facial-facial anastomosis in cats.

The ability of the facial motor system to adapt to a new motor function was studied in alert cats after unilateral transection, 180 degrees rotation and suture of the zygomatic nerve, or transection and cross-anastomosis of the proximal stump of the buccal nerve to the distal stump of the zygomatic nerve. These procedures induced reinnervation of the orbicularis oculi (OO) muscle by different OO- or mouth-related facial motoneurons. Eyelid movements and the electromyographic activity of the OO muscle were recorded up to 1 year following the two types of anastomosis. Animals with a zygomatic nerve rotation recovered spontaneous and reflex responses, but with evident deficits in eyelid kinematics, i.e. the proper regional distribution of OO motor units was disorganized by zygomatic nerve rotation and resuture, producing a permanent defect in eyelid motor performance. Following buccal-zygomatic anastomosis, the electrical activity of the OO muscle was recovered after 6-7 weeks, but air puff-, flash- and tone-evoked reflex blinks never reached the control values on the operated side. Electromyographic OO activities and lid movements corresponding to licking and deglutition activities were observed on the operated side in buccal-zygomatic anastomosed animals up to 1 year following surgery. Mouth-related facial motoneurons did not readapt their discharges to the kinetic, timing and oscillatory properties of OO muscle fibres. A significant hyper-reflexia was observed following both types of nerve repair in response to air puffs, but not to light flashes or tones. In conclusion, adult mammal facial premotor circuits maintain their motor programmes when motoneurons are induced to reinnervate a foreign muscle, or even a new set of muscle fibres.

Complete traumatic brachial plexus palsy. Treatment and outcome after repair.

Seventy-eight patients who had a complete brachial plexus palsy caused by a stretching injury were operated on by the same surgeon between January 1980 and December 1991. The aim of the operative intervention was to obtain the best functional result, including at the level of the hand, that was possible in view of the initial lesions and the intraoperative findings. Therefore, the treatment strategy included not only nerve repair with grafting (124 grafts) or nerve transfer (twenty-seven transfers) but also palliative procedures, the latter of which sometimes were performed several years later. Sixty-three patients were evaluated by an independent observer at least three years postoperatively. The results associated with each type of lesion and each type of nerve repair were assessed according to the function of the muscles that were innervated by the recipient nerve. Six patients had a neurolysis only. The remaining fifty-seven patients had grafts or nerve transfers to repair the biceps. Thirty-six of the fifty-seven received a rating of 3+ or more (meaning that the patient was able to flex the elbow repeatedly); the remaining twenty-one received a rating of 3 or less (meaning that the patient was able to flex the elbow only once or not at all), which we considered unsatisfactory. The function of the triceps recovered after eleven of thirty-one procedures that were performed to restore that nerve; that of the extensor carpi radialis, after five of thirty-one procedures; that of the flexor carpi radialis, after six of thirty-one procedures; and that of the flexor digitorum, after four of thirty-one procedures. A statistical analysis revealed that an operative delay of less than six months was a significant factor with respect to recovery of the function of the biceps (p = 0.003). The thirty-nine grafts that were sutured onto the lateral or posterior cord produced better results than did the thirty-six that were sutured onto the distal branches (the musculocutaneous and radial nerves); however, with the numbers available, this difference was not found to be significant (p = 0.08). Eleven patients had a successful result (a rating of 3+ or more) and eight, a fair or poor result, with respect to recovery of biceps function after transfer of the spinal accessory nerve to the musculocutaneous nerve. Overall, twenty-nine patients had relief of pain postoperatively. Sixteen patients had grade-3 pain preoperatively compared with only three after the operation. According to a self-rating scale, twenty-five patients were satisfied with the overall result, sixteen were fairly satisfied, and twenty-two were dissatisfied.

Nerve repair and axonal transport: Distribution of axonally transported proteins during maturation period in regenerating rabbit hypoglossal nerve

The distribution of fast migrating [ 3H]leucine-labelled proteins was studied in transected and repaired rabbit hypoglossal nerves. The nerves were repaired 90 days earlier with mesothelial chamber or epineurial suture technique. Fast migrating radio-labelled proteins were transported into the distal nerve segment and neurophysiological recordings from the tongue as well as the presence of myelinated axons in the distal nerve segment verified successful regeneration. The total amount of radioactivity was increased in repaired nerves as compared to contralateral nerves. In both groups there was a significant accumulation of radiolabelled proteins at the site of lesion. Nerves repaired with mesothelial chambers showed significantly more radioactivity in the distal nerve segment as compared to sutured nerves. The present study indicates long-standing effects on axonal transport system after both types of nerve repair. It is our opinion that axonal transport studies are a valuable complement when evaluating experimental nerve repair.

EPINEURIAL VS. PERINEURIAL REPAIR

Previous work concerning the efficacy of different types of nerve repair has been reviewed. We describe a model in which epineurial and perineurial suture techniques were studied by quantitative ultramicroscopy and electrophysiology. In this model, we believe suture of the perineurium was shown to have a slight advantage over suture of the epineurium. Microscopic control and fascicular alignment are advocated to increase the percentage of axons growing into the distal stump and the periphery. The model described should lend itself to the study of other traumatic peripheral neuropathies.