Comparison of Burn Depth at Different Temperatures on Ex Vivo Human Skin with Standardized Model and Comparison of the Results with Rat Contact Burn Model

Aim: Burns are still an important mortality and morbidity problem worldwide. Clinical studies are limited, owing to ethical concerns and an inability to achieve standardization. Therefore, studies are concentrated on experimental models. However, there are still a lot of questions that await resolution. Additionally, the relevance of animal models on human skin (HS) is unknown. From this point of view, this study aims to evaluate the depth of burn on ex vivo HS and to compare the HS results with those of rats. Materials and Methods: Skins of patients, after obtaining informed consent, that underwent full thickness healthy skin excision (abdominoplasty), except for experimental purposes, have been included. A total of three different temperatures (60, 80 and 100 °C) using two different weight forces (0.88 kg/cm2 for high and 0.21 kg/cm2 for low) using standardized apparatus facilitated the formation of study groups. In all groups, healthy dermis-epidermis burn depth was compared. Results: No difference was detected between healthy HS depths from the various samples taken from different donors that were to be tested. The lowest result (10.5±0.7% burn depth ) was seen in the 60 °C low weight force group and the highest was seen in the 100 °C high weight force group (92.0±2.7). As for the 80 °C high pressure group vs the 100 °C low pressure groups, a significant difference was noted. Conclusion: Ex vivo HS can be used as an experimental burn model. It has been shown that standardized depth of burn can be achieved using standardized apparatus. However, the different depth of burn indicates that control of parameters (pressure, time, temperature) is mandatory

Can a Small Intestine Segment Be an Alternative Biological Conduit for Peripheral Nerve Regeneration?

Background: Autologous nerve grafts are used to bridge peripheral nerve defects. Limited sources and donor site morbidity are the major problems with peripheral nerve grafts. Although various types of autologous grafts such as arteries, veins and muscles have been recommended, an ideal conduit has not yet been described. Aims: To investigate the effectiveness of a small intestinal conduit for peripheral nerve defects. Study Design: Animal experimentation. Methods: Twenty-one rats were divided into three groups (n=7). Following anaesthesia, sciatic nerve exploration was performed in the Sham group. The 10 mm nerve gap was bridged with a 15 mm ileal segment in the small intestinal conduit group and the defect was replaced with orthotopic nerve in autologous nerve graft group. The functional recovery was tested monthly by walking-track analysis and the sciatic functional index. Histological evaluation was performed on the 12th week. Results: Sciatic functional index tests are better in autologous nerve graft group (-55.09±6.35); however, during follow-up, progress in sciatic functional index was demonstrated, along with axonal regeneration and innervation of target muscles in the small intestinal conduit group (-76.36±12.08) (p<0.05). In histologic sections, distinctive sciatic nerve regeneration was examined in the small intestinal conduit group. The expression of S-100 and neurofilament was observed in small intestinal conduit group but was less organised than in the autologous nerve graft group. Although the counted number (7459.79±1833.50 vs. 4226.51±1063.06 mm2), measured diameter [2.19 (2.15- 2.88) vs. 1.74 (1.50-2.09) µm] and myelin sheath thickness [1.18 (1.09-1.44) vs. 0.66 (0.40-1.07) µm] of axons is significantly high in the middle sections of autologous nerve graft compared to the small intestinal conduit group, respectively (p<0.05), the peripheral nerve regeneration was also observed in the small intestinal conduit group. Conclusion: Small intestinal conduit should not be considered as an alternative to autologous nerve grafts in its current form; however, the results are promising. Even though the results are no better than autologous nerve grafts, with additional procedures, it might be a good alternative due to harvesting abundant sources without donor site morbidity.Background: Autologous nerve grafts are used to bridge peripheral nerve defects. Limited sources and donor site morbidity are the major problems with peripheral nerve grafts. Although various types of autologous grafts such as arteries, veins and muscles have been recommended, an ideal conduit has not yet been described. Aims: To investigate the effectiveness of a small intestinal conduit for peripheral nerve defects. Study Design: Animal experimentation. Methods: Twenty-one rats were divided into three groups (n=7). Following anaesthesia, sciatic nerve exploration was performed in the Sham group. The 10 mm nerve gap was bridged with a 15 mm ileal segment in the small intestinal conduit group and the defect was replaced with orthotopic nerve in autologous nerve graft group. The functional recovery was tested monthly by walking-track analysis and the sciatic functional index. Histological evaluation was performed on the 12th week. Results: Sciatic functional index tests are better in autologous nerve graft group (-55.09±6.35); however, during follow-up, progress in sciatic functional index was demonstrated, along with axonal regeneration and innervation of target muscles in the small intestinal conduit group (-76.36±12.08) (p<0.05). In histologic sections, distinctive sciatic nerve regeneration was examined in the small intestinal conduit group. The expression of S-100 and neurofilament was observed in small intestinal conduit group but was less organised than in the autologous nerve graft group. Although the counted number (7459.79±1833.50 vs. 4226.51±1063.06 mm2), measured diameter [2.19 (2.15- 2.88) vs. 1.74 (1.50-2.09) µm] and myelin sheath thickness [1.18 (1.09-1.44) vs. 0.66 (0.40-1.07) µm] of axons is significantly high in the middle sections of autologous nerve graft compared to the small intestinal conduit group, respectively (p<0.05), the peripheral nerve regeneration was also observed in the small intestinal conduit group. Conclusion: Small intestinal conduit should not be considered as an alternative to autologous nerve grafts in its current form; however, the results are promising. Even though the results are no better than autologous nerve grafts, with additional procedures, it might be a good alternative due to harvesting abundant sources without donor site morbidity

Can a Small Intestine Segment Be an Alternative Biological Conduit for Peripheral Nerve Regeneration?

Background: Autologous nerve grafts are used to bridge peripheral nerve defects. Limited sources and donor site morbidity are the major problems with peripheral nerve grafts. Although various types of autologous grafts such as arteries, veins and muscles have been recommended, an ideal conduit has not yet been described