A much-debated subject in the last 20 years, the recovery after peripheral nerve injury still remains one of the most researched themes of our days. Although the central nervous system has not exhibited any ground-breaking discoveries in matters of healing through surgical procedures, this is not the case for the peripheral nervous system (PNS). The PNS recovery after injury has improved over the years so we now speak of time and percentage of rehabilitation. The increased interest for this subject is a result in the development of the medical technique, that allowed the creation of new molecules capable to improve the regeneration rate. Furthermore, the evolution in diagnostic parameters, as well as the possibility of a thorough follow-up, contributed to the ascending research of this field. One must not forget that all experimental studies have as endpoint obtaining safe and reproducible solutions which can be applied in treating patients with peripheral nerve injury. We will briefly present the microscopic events that occur following a peripheral nerve injury, the key factors which influence their regeneration as well as the classical techniques used to repair them. However, the most intriguing topic in nerve regeneration is not related to the surgical procedure (considered to be the Gold Standard in whole nerve injury), but rather the helping substances that facilitate a faster and better recovery.

When learning the basics of microsurgery, a trainee must be equipped with patience and perseverance in order to evolve. One must have the ground knowledge when it comes to peripheral nerve injury and nerve regeneration process in order to fully understand that the technique is vital for the outcome and final results. Furthermore, a trainee must practice on non-living tissue before performing successful in vivo operations and even in this case, one may be confronted with problems regarding the surgical technique. [1] The following article aims to reveal the main problems/mistakes when performing sciatic nerve surgery in an in vivo experimental model and the solutions for these problems.

Peripheral nerve injuries are one of the most important causes for disability generating considerable costs around the world. Appropriate assessment of the extent of peripheral nerve lesions and the choice of the right therapeutic protocol remain some of the biggest challenges. Non-invasive neuroimaging approaches are suitable in managing peripheral nerve repairs, providing in the same time accuracy details in structural neural detection, with minimal discomfort at a low cost. Medical imaging technology development has led to progress in examination of peripheral nervous system, using a series of tools and methods, such as: ultrasonography (US), positron emission tomography (PET), magnetic resonance imaging (MRI) and magnetic diffusion tensor imaging (DTI). In this study, we evaluated the regeneration process in Wistar rats after sciatic nerve defects repair with 4 different techniques (i.e. nerve graft, rat aorta used as a nerve conduit, rat aorta filled with platelet rich plasma (PRP) and rat aorta filled with stem cells) by using MRI investigation alongside the clinical evaluation. Our results showed that among the 4 batches, the PRP batch had the best results in muscle atrophy condition (both on MRI scan and on gastrocnemius index); on the second place the stem cell batch, then the nerve graft batch and finally the aortic conduit batch. MRI proved to be a reliable non-invasive monitoring method and showed good result in correlation with the footprint test (sciatic functional index) and the gastrocnemius index

The baseline for any key research in nerve regeneration is an experimental model and the sciatic nerve in the rat model is the workhorse in this field. Although physically resistant to external traumas, a surgical intervention constitutes a major distress even for a rat. In the following presentation, we will analyse the learning curves for different stages in the rat sciatic nerve surgery as well as possible factors which influence these times.