Nerve wrapping for recurrent compression neuropathy: A systematic review

Epineural Scarring Visualization and Noninvasive Quantification of a Severe Posttraumatic Complication: An Experimental Magnetic Resonance Neurography Study

AIM

Peripheral nerve scarring is a severe yet common complication following nerve injury or surgery that can lead to impaired nerve function, including chronic pain and sensory or motor deficits. In this study, we aimed to establish high-resolution magnetic resonance neurography (MRN) to accurately visualize and monitor de novo-formed epineural fibrotic adhesions (EFAs) of the sciatic nerve in a rat nerve injury model.

METHODS

Employing an established model to induce overshooting EFA, the study included 3 experimental groups of animals (n = 6 each): a positive control group (PC), an intervention group (IG), and a sham group. All groups underwent surgical nerve exposure: both PC and IG received an application of 10 μL 2.5% glutaraldehyde to induce EFA, but only IG received an additional preventive wrapping of the nerve with a collagen-containing matrix. Magnetic resonance imaging was performed 6, 8, and 12 weeks postoperatively using a standardized protocol including T2w and T1w without and with contrast media. Motor function and nerve regeneration was assessed using the visual static sciatic index. Histological specimens were obtained 12 weeks postoperatively and correlated with imaging.

RESULTS

On high-resolution MRN, prominently contrast-enhancing epineural sleeves were present in vivo, which corresponded to histologically confirmed EFA (ratio of EFA to nerve area MRN 1.512 ± 0.106 vs histological ratio 1.459 ± 0.208, nonsignificant). As expected, average EFA in IG (0.310 ± 0.118 mm2) was smaller than in PC (0.909 ± 0.212 mm2, P < 0.01). Also, the average EFA in sham (0.386 ± 0.030 mm2) was less pronounced than in PC (P < 0.01). There was no significant difference in the average EFA between IG und sham. The EFA correlated with the functional outcome, which was measured by visual static sciatic index (correlation coefficient -0.59, P < 0.05).

CONCLUSIONS

The results of the present study for the first time confirm the clinical observation that epineural thickening on contrast-enhanced T1w imaging following manipulation to a nerve indeed corresponds to overshooting epineural scarring, which may be linked to impaired nerve function. This can be followed noninvasively in vivo over time providing an important basis for clinical decision-making in cases where further invasive therapies may be necessary.

Porcine submucosal extracellular matrix wrapping of the ulnar nerve in revision cubital tunnel surgery

The wrapping technique aims to protect the nerve when the nerve bed is compromised or more commonly to prevent the recurrence of scar tethering following neurolysis. A wrap provides a physical barrier to scar and helps restore the paraneurial gliding layer. This study aimed to evaluate the results of the AxoGuard® nerve protector, a porcine-derived submucosal extracellular matrix (PECM), used as an adjunct in persistent or recurrent cubital tunnel syndrome (CuTS). This retrospective cohort study evaluated patients diagnosed, between 2012 and 2020, with neuropathic pain who underwent revision surgery. Patients were categorised into Group A (revision surgery only) and Group B (revision surgery and adjunctive PECM nerve wrapping). Disease severity was scored at the baseline and six months post-operatively using the McGowan classification. A linear regression model was used to assess the effect of wrapping the ulnar nerve on the clinical outcome at six months. Fifty-nine nerves were treated; among them, adjunctive PECM wrapping was used in 32 nerves. Disease severity at baseline was similar between the groups. After adjusting for differences in baseline characteristics, participants in Group B improved with a significant difference of 0.43 McGowan points over Group A (95% CI (0.01-0.86), p = 0.049). There were no implant-related complications. Group B improved with excellent or good outcomes in 84.4% patients at the final follow-up. Persistent or recurrent CuTS were associated with neuropathic pain and significant nerve scar tether. The use of PECM appears to lead to improved clinical symptoms, possibly by reducing adhesions and encouraging physiological glide. LEVEL OF EVIDENCE: Level III evidence.

Efficacy of adipose-derived stem cells in preventing peripheral nerve adhesion and promoting nerve regeneration: A laboratory investigation in a rat model

BACKGROUND

Neurolysis alone or administration of anti-adhesion products after neurolysis is performed to treat peripheral nerve adhesion; however, the recovery of nerve function is poor. This study aimed to investigate the efficacy of adipose-derived stem cells (ADSCs) for peripheral nerve adhesion in a rat model.

METHODS

As a nerve adhesion procedure, the neural bed was coagulated, and the epineurium of the sciatic nerve was sutured to the coagulated neural bed using nylon. Neurolysis was performed 6 weeks after the nerve adhesion procedure, and saline (control group) or ADSCs (ADSC group) were administered around the nerve where neurolysis was performed. Evaluations were performed 6 weeks after the administration.

RESULTS

The wet weight ratio of the tibialis anterior muscle and nerve conduction velocity, which are indicators of nerve regeneration, were significantly better, while tensile strength, which is an indicator of the severity of nerve adhesion, was significantly lower in the ADSC group than in the control group. In the nerve, the expression of interleukin-10 and transforming growth factor-β in the nerve was significantly higher and that of tumor necrosis factor-α was significantly lower in the ADSC group than in the control group. Furthermore, significantly fewer M1 macrophages and significantly more M2 macrophages were observed in the ADSC group than in the control group. In the perineural scar, significantly fewer perineural collagen fibers and significantly more vascularization were observed in the ADSC group than in the control group.

CONCLUSIONS

ADSCs prevented peripheral nerve adhesion by reducing perineural scarring and enhancing vascularization. Additionally, ADSCs promoted nerve regeneration by decreasing inflammatory cytokine levels and increasing anti-inflammatory cytokine levels, as ADSCs regulated macrophage polarization from M1 to M2 macrophages. These findings hold promise for using ADSCs to treat nerve adhesion.

Bioengineered Nerve Conduits and Wraps

Peripheral nerve injuries are prevalent and their treatments present significant challenges. Among the various reconstructive options, nerve conduits and wraps are popular choices. Advances in bioengineering and regenerative medicine have led to the development of new biocompatible materials and implant designs that offer the potential for enhanced neural recovery. Cost, nerve injury type, and implant size must be considered when deciding on the ideal reconstructive option.

Outcomes following use of VersaWrap nerve protector in treatment of patients with recurrent compressive neuropathies

Epineural scarring following previous carpal or cubital tunnel release can lead to pain and permanent dysfunction. To prevent this cascade, nerve wraps are an option. The purpose of this study was to evaluate outcomes following use of VersaWrap nerve protector during surgical decompression and neurolysis in patients with recurrent compressive neuropathies in the upper extremity. Twenty patients comprised the patient cohort, with a mean postoperative follow-up time of 139 days (range: 42-356 days). There were 13 females and 7 males, with a mean age of 43.4 years. Fourteen surgeries were performed for revision cubital tunnel, 5 for revision carpal tunnel, and 1 for revision radial tunnel syndrome. Average duration of symptoms prior to revision surgery with VersaWrap was 2 years (range 9 months to 6 years). Postoperatively, the mean DASH score was 57.7 and VAS 3.1. Mean s2PD median distribution was 7.3, s2PD ulnar distribution 8.9, m2PD median distribution 6.9 and m2PD ulnar distribution 7.3. All patients had subjective improvement of symptoms and were satisfied with their result. No patients in our cohort required further revisional surgery. In conclusion, the use of VersaWrap as a nerve protector following revision surgery for recurrent compressive neuropathies in the upper extremity was safe and effective. Level of Evidence: IV; retrospective case series.

Reoperative Brachial Plexus Neurolysis After Previous Anatomically Complete Supraclavicular Decompression for Neurogenic Thoracic Outlet Syndrome: A 10-Year Single-Center Case Series

BACKGROUND

Optimal management of recurrent neurogenic thoracic outlet syndrome (NTOS) remains a considerable challenge.

OBJECTIVE

To assess the safety and effectiveness of reoperative brachial plexus neurolysis in patients with recurrent NTOS.

METHODS

From 2009 to 2019, 85 patients underwent reoperative supraclavicular brachial plexus neurolysis for recurrent NTOS after a previous anatomically complete supraclavicular decompression. Data from a prospectively maintained database were analyzed retrospectively.

RESULTS

The mean patient age at reoperation was 36.9 ± 1.3 (range 15-64) years, 75% were female, and the interval after previous primary operation was 2.5 ± 0.2 years. Intervening injury had precipitated recurrent NTOS in 14 patients (16%), and the mean Disability of the Arm, Shoulder, and Hand (QuickDASH) score before reoperation was 65.2 ± 2.6, reflecting substantial disability. Operative findings consisted of dense fibrous scar tissue surrounding/encasing the brachial plexus. Compared with the previous primary operations, reoperations had a shorter operative time (198 ± 4 vs 161 ± 5 minutes, P < .01) and hospital stay (4.4 ± 0.2 vs 3.6 ± 0.1 days, P < .01), but there were no significant differences in the frequency of prolonged hospitalization (7.1% vs 4.7%), early reoperation (3.5% vs 1.2%), or 30-day hospital readmission (8.2% vs 7.1%). During a median follow-up of 4.8 years, QuickDASH scores improved by 23.3 ± 2.6 (34.2% ± 3.6%; P < .01) and patient-rated outcomes were excellent in 24%, good in 42%, fair in 26%, and poor in 8%.

CONCLUSION

Reoperative supraclavicular brachial plexus neurolysis is technically challenging but safe and effective treatment for recurrent NTOS, with significant improvements in symptoms and function. Diminishing perineural scar tissue development and avoiding secondary injury would likely decrease the need for reoperations.

Necrotic Granulomatous Inflammation after Use of Small Intestine Submucosa Matrix for Recurrent Compression Neuropathy

Various techniques exist for treating recurrent carpal and ulnar tunnel syndrome, but AxoGuard nerve wrap has shown promising results for treatment of compression neuropathies when used in conjunction with neurolysis and tenosynovectomy. Prior results demonstrate no safety concerns, and there have not been any reported cases of infection, persistent inflammation, or recurrent perineural fibrosis. A 41-year-old, right-hand-dominant woman experienced repeated bouts of carpal and ulnar tunnel syndromes, which were treated with a small intestine submucosa matrix wrap around the median and ulnar nerves in the wrist. Here, we report a case of necrotic granulomatous inflammation 2.5 months after AxoGuard xenograft nerve wrap was placed around the median and ulnar nerves. As a salvage, NuShield placental allograft was wrapped around the median nerve, which has shown promising results at several months follow-up. Placental allograft nerve wraps represent a useful tool in compression neuropathy resistant to autografts, xenografts, and revision decompression operations.

Peripheral Nerve Healing: So Near and Yet So Far

Peripheral nerve injuries represent a considerable portion of chronic disability that especially affects the younger population. Prerequisites of proper peripheral nerve injury treatment include in-depth knowledge of the anatomy, pathophysiology, and options in surgical reconstruction. Our greater appreciation of nerve healing mechanisms and the development of different microsurgical techniques have significantly refined the outcomes in treatment for the past four decades. This work reviews the peripheral nerve regeneration process after an injury, provides an overview of various coaptation methods, and compares other available treatments such as autologous nerve graft, acellular nerve allograft, and synthetic nerve conduits. Furthermore, the formation of neuromas as well as their latest treatment options are discussed.