Nerve autografts and tissue-engineered materials for the repair of peripheral nerve injuries: a 5-year bibliometric analysis

With advances in biomedical methods, tissue-engineered materials have developed rapidly as an alternative to nerve autografts for the repair of peripheral nerve injuries. However, the materials selected for use in the repair of peripheral nerve injuries, in particular multiple injuries and largegap defects, must be chosen carefully. Various methods and materials for protecting the healthy tissue and repairing peripheral nerve injuries have been described, and each method or material has advantages and disadvantages. Recently, a large amount of research has been focused on tissue-engineered materials for the repair of peripheral nerve injuries. Using the keywords ＂peripheral nerve injury＂, ＂autotransplant＂, ＂nerve graft＂, and ＂biomaterial＂, we retrieved publications using tissue-engineered materials for the repair of peripheral nerve injuries appearing in the Web of Science from 2010 to 2014. The country with the most total publications was the USA. The institutions that were the most productive in this field include Hannover Medical School （Germany）, Washington University （USA）, and Nantong University （China）. The total number of publications using tissue-engineered materials for the repair of peripheral nerve injuries grad- ually increased over time, as did the number of Chinese publications, suggesting that China has made many scientific contributions to this field of research.

An Experimental Study on the Optimal Timing for the Repair of Incomplete Facial Paralysis by Hypoglossal-facial‘Side'-to-side Neurorrhaphy in Rats

Objective To investigate the optimal timing for the repair of persistent incomplete facial paralysis by hypoglossal-facial ‘side＇-to-side neurorrhaphy in rats. Methods A total of 30 adult rats with crushed and bulldog-clamped facial nerve injury were randomly divided into 5 groups（n = 6 each） that were subjected to injury without nerve repair or with immediate repair, 2-week-delayed repair, 4-week-delayed repair, or 8-week-delayed repair. Three months later, the effects of repair in each rat were evaluated by facial symmetry assessment, electrophysiological examination, retrograde labeling, and axon regeneration measurement. Results At 3 months after injury, the alpha angle significantly increased in the group of rats with 4-week-delayed repair compared with the other four groups. Upon stimulation of the facial nerve or Pre degenerated nerve, the muscle action potentials MAPs were recorded in the whisker pad muscle, and the MAP amplitude and area under the curve in the 4-week-delayed repair group were significantly augmented at 3 months post-injury. Similarly, the number of retrograde-labeled motor neurons in the facial and hypoglossal nuclei was quantified to be significantly greater in the 4-week-delayed repair group than in the other groups, and a large number of regenerated axons was also observed. Conclusion The results of this study demonstrated that hemi HN-FN neurorrhaphy performed 4 weeks after facial nerve injury was most effective in terms of the functional recovery of axonal regeneration and activation of facial muscles.

Peripheral nerve allograft:how innovation has changed surgical practice

The landscape of available technology and surgical technique has changed over the last several decades,thus leading to changes in the peripheral nerve repair surgical algorithm.Neurorrhaphy is a common procedure;however,it is well recognized that nerve repair should be performed tensionless,thus preventing the ability to perform direct repair with a nerve gap.Historically,nerve gaps were repaired with autograft.However,autograft surgery has been associated with complications such as numbness and chronic pain,which left surgeons searching for alternatives.Nerve allografts were first utilized in the 1800s but failed due to the immune response.In the modern era,they were again utilized in the 1980s,but did not gain popularity because of the need for the use of immunosuppressants.It was evident through the 1990s that continued innovation in peripheral nerve repair was needed,as studies showed that only approximately 50% of patients with nerve gap repair achieved good or excellent outcomes.In the 2000s,the advent of an engineered nerve allograft(Avance■Nerve Graft)changed the landscape of peripheral nerve repair.Early clinical evaluation of Avance showed that adequate sensation was able to be achieved in nerve gaps up to 30 mm,providing an alternative to autografts.As engineered nerve allograft use became more conventional,studies showed 87.3% meaningful recovery in nerve gaps up to 50 mm.Furthermore,recent studies have shown that gaps between 50-70 mm have shown 69% meaningful recovery.While technology and surgical technique continue to improve,these results are promising for large nerve gap repair.