Effects of Metal Fragments on Nerve Healing in Extremity Injuries Using a Rat Peroneal Nerve Model

Anatomic variations of brachial and lumbosacral plexus models in different rat strains

PURPOSE

Selection of an appropriate model for preclinical assessment of new methods of peripheral nerve injury management is crucial. This report presents anatomic variations within brachial and lumbosacral plexuses in three selected rat strains Sprague Dawley (Hsd:Sprague Dawley SD), Lewis (LEW/SsNHsd), and Athymic Nude (Hsd:RH-Foxn1^rnu ) rats.

METHODS

Based on their strain eighteen rats were divided into three groups. A total of 90 brachial plexus nerves (axillary, musculocutaneous, median, ulnar, and radial nerves) and 72 lumbosacral plexus nerves (sciatic, tibial, common peroneal, and sural nerves) were analyzed for the length, diameter and correlation with the body weight. A detailed anatomic course of each nerve within the brachial and lumbosacral plexuses was outlined.

RESULTS

The sural nerve was the longest nerve in all studied rat strains, whereas the sciatic nerve had the largest diameter. Comparison of all the nerves' length demonstrated that the Lewis rat sciatic and sural nerves were significantly shorter (P < 0.05). No significant differences in nerve diameters were found among the analyzed rat strain groups. Significant correlation was revealed between the length of sciatic nerve and the rats' weight, which is irrelevant to the rats' genetic background.

CONCLUSIONS

This study confirmed that nerves' length within rat's brachial and lumbosacral plexus depends on the inter-individual variations within the rat strains rather than on the differences in the peripheral nerve development, which is inherent to the specific rat strain. Correlation between the nerve length and body weight, suggests that bigger rats should be considered for studies requiring access to the long nerves. © 2016 Wiley Periodicals, Inc. Microsurgery 37:327-333, 2017.

Clinical aspects of ballistic peripheral nerve injury: shrapnel versus gunshot

OBJECTIVES

Ballistic injuries to peripheral nerves pose special challenges in terms of indications, timing and type of surgical intervention. The aim of the present work was to analyze our experience in the surgical treatment of peripheral nerve ballistic injuries with respect to the mechanism of injury (gunshot versus shrapnel), and identify common and dissimilar prognostic factors in both types of injury.

METHODS

This study was conducted on 42 patients totaling 58 nerves. Twenty-two patients (32 nerves) were injured by gunshot and 20 patients (26 nerves) by shrapnel. Median postoperative follow-up was 33 months (range 12 months to 14 years).

RESULTS

Overall postoperative outcome appears to be more favorable for gunshot-wound (GSW) patients than shrapnel-injured patients, especially in terms of neuropathic pain relief (75 % vs. 58 % respectively, p < 0.05). Presence of foreign particles in shrapnel injured patients has a negative impact on the surgical outcome in terms of rate of pain improvement (28 % compared to 67 % in patients with and without foreign particles, respectively). Nerve graft reconstruction, rather than neurolysis, seems to be the more beneficial treatment for shrapnel-induced neuropathic pain (100 % vs. 47 % in improvement rate, respectively). Early surgical intervention (median 2 months after injury) significantly relieved neuropathic pain in 83 % of shrapnel-injured patients compared to 58 % in patients operated later.

CONCLUSIONS

This study suggests that shrapnel injury is more destructive for nerve tissue than gunshot injury. Our impression is that early surgical intervention in shrapnel injuries and split nerve grafting (especially when small fragments are recognized in the nerve) significantly improve the patient's functional activity and quality of life.

Surgeon perspectives on alternative nerve repair techniques

BACKGROUND

Over the past five decades, microsuturing has been established as the "gold standard" for nerve repair. Alternative techniques such as fibrin glue, protein "welds", and nerve connectors have been met with variable enthusiasm. While advancements in this area continue, there is little data on surgeon attitude and acceptance of these new techniques.

METHODS

A short questionnaire was electronically distributed to the members of the American Society for Surgery of the Hand and the American Association of Hand Surgery. Survey questions ascertained demographic information of participants (specialty, years in practice, practice setting, etc.), attitudes about current techniques (what techniques currently used, why, etc.), and attitudes about new techniques (openness to trying, factors that would persuade for/against, etc.). The surveys were distributed and administered online. Data gathered from responses was analyzed looking for general trends and stratified based on demographic data.

RESULTS

The majority of responders still consider microsuturing as the gold standard for primary nerve repair, and it is by far the most utilized technique. However, over 90 % also reported that they either currently use or would consider using alternate techniques. Common barriers to utilizing alternate techniques included lack of data regarding outcomes and unfamiliarity with new techniques. Only 40 % of responders considered metal as safe around nerves, but most consider absorbable polymers safe. None of the underlying demographic variables including years in practice, number of nerve repair surgeries performed per month, practice setting, or specialty affected these general trends.

CONCLUSIONS

Most surgeons performing nerve repairs prefer suturing as their primary repair technique, but a vast majority is open to utilizing alternate repair techniques, especially those that improve outcomes with a faster and easier procedure. While not able to direct clinical practice guidelines, this study can be used to direct focus and funding of further alternate nerve repair techniques.