Sciatic Nerve Plastic Surgery using Autologous Adipose Tissue.

The aim of the investigation is to study structural alterations of autologous omental adipose tissue in a silicon conduit and to evaluate its possible use for regeneration of the sciatic nerve in diastasis. Materials and Methods: Mature outbred male Wistar rats have been used in the study. The animals were divided into 7 experimental groups with complete transection of the sciatic nerve on the right side at the mid-third level of the thigh. The ends of the transected nerve were pulled apart, inserted into a silicon conduit, and secured to the epineurium. The conduit of group 1 (control) was filled with a saline solution; in group 2, it was filled with an autologous omental adipose tissue with saline solution. Intravital labeling of the omental adipose tissue with the lipophilic PKH 26 dye (in group 3) was used for the first time to find out whether the omental cells were involved in formation of the regenerating nerve. Diastasis in groups 1-3 was 5 mm, the postoperative period was 14 weeks. The dynamics of the omental adipose tissue changes in groups 4-7 was assessed by placing the omental tissues into the conduit covering 2 mm of diastasis. The postoperative period was 4, 14, 21, and 42 weeks. Results: In group 2 (omental adipose tissue + saline), the clinical condition of the damaged limb after 14 weeks may be evaluated as satisfactory and approximating to the intact parameters as compared to group 1 where the conduit was filled with a saline solution only. The sum of large and medium-sized nerve fibers in group 2 was 2.7 times greater than that in group 2. The milled omental adipose tissue inside the conduit changed its volume and structure in nerve diastasis and was constantly utilized up to complete elimination over time. The omental cells integrated into the newly formed nerve in the graft area. Conclusion: As a graft, the adipose tissue of the autologous omentum produces a stimulating effect on the post-traumatic regeneration of the sciatic nerve.

Reconstruction of the Rat Sciatic Nerve by Using Biodegradable and Non-Biodegradable Conduits.

The aim of the study was to compare two types of conduits made of either non-resorbable Reperen or resorbable Tissucol for their effects on the regeneration of the rat sciatic nerve under conditions of stump diastasis. MATERIALS AND METHODS: The experiments were carried out using outbred white male rats of the reproductive age (n=14). The animals were divided into three groups: group 1, intact (n=5), used for studying the morphology of the sciatic nerve; group 2 (n=4) - nerve plastic surgery was performed using a conduit made of non-resorbable Reperen; group 3 (n=5) - surgery was performed using a conduit made of resorbable Tissucol. The animals were anesthetized with isoflurane. After a complete transection of the sciatic nerve in the middle third of the thigh, its stumps were inserted into a conduit of an internal diameter of 2 mm and a length of 10 mm, filled with saline. Diastasis of 5 mm in length was created by spreading the nerve ends and securing the epineurium to the tube edges with 8/0 polypropylene sutures. A total count of myelinated nerve fibers was performed in the area of repair (tubulation) and the distal part of the nerve; the formation of connective tissue sheaths was assessed 14 weeks after the operation. RESULTS: According to the morphological assessment, both types of conduits (resorbable and non-resorbable) caused the similar number of fibers to restore in the distal part of the repaired nerve; clinical characteristics of the animals in both groups were close to each other and to the norm. CONCLUSION: The results allow us to consider the conduit made of non-resorbable Reperen as a device promising for neuroplasty along with the resorbable conduit made of Tissucol.

Ultrastructural Morphological Characterization of Right Atrial and Left Ventricular Rat Cardiomyocytes during Postreperfusion Period.

Immunocytochemistry and transmission electron microscopy were employed to examine the ultrastructural morphometric parameters of the left ventricular cardiomyocytes and right atrial secretory myocytes in rats during early and delayed postreperfusion periods. The revealed alterations in these cells are stereotypical, but differed by their severity, probably due to specific morphofunctional peculiarities of these heart structures.