Yazar "Aygul, Recep" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    The effect of a gap concept on peripheral nerve recovery in modified epineurial neurorrhaphy: An experimental study in rats
    (Wiley, 2022) Ismayilzade, Majid; Ince, Bilsev; Zuhour, Moath; Oltulu, Pembe; Aygul, Recep
    Background: Several factors such as surgical approach that only consider topographic anatomy; inadequate fascicular alignment, extraepineurial sprouting in the repair zone; contact of axons with the suture area are the disadvantages of epineurial neurorrhaphy. Accordingly, axonal mismatch, neuroma, and unfavorable nerve recovery become inevitable. Neurotropism is the theory clarifying appropriate matching of the nerve fibers independently without needing surgical approach. The studies comparing the primary nerve repair with the nerve defects bridged in different ways demonstrated better outcomes of nerve recovery in the groups with a nerve gap. In this study, we aimed to demonstrate the effects of the gap concept in primary nerve repair bridged by own epineurium. We hypothesized that this technique will provide better results in terms of peripheral nerve recovery and will significantly eliminate the occurrence of a neuroma, which is quite possible in epineurial neurorrhaphy. Materials and Methods: A total of 35 Wistar female rats weighing 200 similar to 250 g were randomly divided into five groups each with seven rats. Sham controls constituted Group 1, while the rats with epineural neurorrhaphy were included in Group 2. The remaining three groups were the study groups. In Group 3, after the sciatic nerve transection, epineurium of the distal segment was sleeved and preserved. A 2-mm axonal segment was removed from the epineurium free distal ending and no any procedure was applied to the proximal ending of the transected sciatic nerve. Epineuriums of the both sides were approximated and repaired. In Group 4, a 2-mm axonal segment was removed from the proximal ending of the sciatic nerve after preservation of epineurium and no any procedure was applied to the distal part of sciatic nerve. Epineuriums of the both sides were approximated and repaired. In addition, in Group 5, after epineuriums were sleeved in the both distal and proximal stumps, a 1-mm nerve segment was removed from both endings and epineuriums were Correspondence repaired in the middle bridging a 2-mm axonal gap again. After a 3 months follow-up period Sciatic Functional Index (SFI) was measured by walking track analysis; the area under the evoked compound muscle action potential (CMAP) and latency periods were calculated via electromyographic (EMG) analysis; and histopathological evaluation were performed to compare the parameters of edema, fibrosis, inflammation, vascularization, axonal degeneration, axonal density, myelination, disorganization, and neuroma occurrence. Vascular structures and nerve fibers were counted at x200 magnification: +1, +2, and +3 indicated the presence of 0-15, 16-30, and >30 structures, respectively. For uncountable parameters (edema, disorganization, myelination, fibrosis, and inflammation): +1 indicated mild, +2 indicated moderate, and +3 indicated severe. Results: The differences between the groups with axonal gap repair and epineural neurorrhaphy were not significant regarding to SFI. The areas under CMAP were as follows: 27.9 +/- 5.9 (Delta = 12.1%) in Group 1; 16.5 +/- 5.5 (Delta = 6.3%) in Group 2; 14.1 +/- 6.2 (Delta = 4.8%) in group 3; 13.8 +/- 2.3 (Delta = 9.2%) in Group 4, and 22.5 +/- 18.3 (Delta = 2.2%) in Group 5. Group 5 (1 mm gap in the distal +1 mm gap in the proximal segments) had a significantly better result in terms of the area under CMAP with the value of 22.5 +/- 18.3 m/Mv (p = .031). Axonal density was 0.9 +/- 0.6 (Delta = 2.2%) in Group 2, 2.4 +/- 0.3 (Delta = 5.1%) in Group 3, 2.8 +/- 0.1 (Delta = 7.7%) in Group 4, and 2.8 +/- 0.2 (Delta = 4.8%) in Group 5. Myelination was 1.1 +/- 0.5 (Delta= 3.4%) in group 2, 2.2 +/- 0.2 (Delta = 6.7%) in group 3, 2.4 +/- 0.4 (Delta = 6.0%) in Group 4, and 2.7 +/- 0.3 (Delta = 4.6%) in Group 5. Disorganization was 2.3 +/- 0.4 (Delta = 4.1%) in Group 2, 1.2 +/- 0.2 (Delta = 7.7%) in Group 3, 1.3 +/- 0.2 (Delta = 6.5%) in Group 4, and 1 +/- 0.3 (Delta = 5.9%) in Group 5. And, neuroma occurrence was found 2.2 +/- 0.6 (Delta = 2.8%) in Group 2 and 0.3 +/- 0.2 (Delta= 0.1%) in Group 4 while neuroma was not encountered in Group 3 and Group 5. Comparison between the epineurial neurorrhaphy group and the groups with axonal defect revealed the statistically significant results in the factors of axonal density (p =.001), myelination (p = .028), disorganization (p = .016) and neuroma (p = .001). Conclusions: Creating axonal gap bridged by own epineurium showed favorable results comparing with epineurial neurorrhaphy. Resection of a 1 mm axonal segment from the proximal and distal stumps following the epineurial sleeve procedure and performing the epineurium- only repair can facilitate the nerve regeneration. The feasibility of the described technique has been demonstrated in a small rat model and must be further validated in larger animals before clinical testing.
  • Küçük Resim Yok
    Öğe
    Evaluation of the effectiveness of the tuba uterina tubular flap in the peripheral nervous system regeneration in rats
    (Taylor & Francis Ltd, 2022) Yildirim, Mehmet Emin Cem; Dadaci, Mehmet; Ince, Bilsev; Uyar, Ilker; Yarar, Serhat; Oltulu, Pembe; Aygul, Recep
    Nerve conduits could be used to provide a bridge between both nerve endings. In this study, the tuba uterina of female rats were prepared in a vascularized pedicled flap model and it used as a nerve conduit. The aim was to investigate the effectiveness of a vascularized pedicle nerve conduit and its ciliated epithelium in a sciatic nerve defect. The study was conducted between May and August 2018, and used a total of 60, 14-16-week-old female Wistar albino rats. Six groups were created; Cut and Unrepaired Group, Nerve Graft Group, Flap-Forward Group (Tuba uterina tubular flap, forward direction), Flap-Reversed Group (Tuba uterina tubular flap, reverse direction), Graft-Forward Group (Tuba uterina tubular graft, forward direction) and Graft-Reverse Group (Tuba uterina tubuler graft, reverse direction). Nerve regeneration was evaluated 3 months (90 days) after the surgery by the following methods: (1) Sciatic Functional Index (SFI) measurement, (2) Electromyographic (EMG) assessment, (3) Microscopic assessment with the light microscope and (4) Microscopic assessment with the electron microscope. According to the SFI, EMG and microscopic assessments with the light and electron microscope, it was observed that the transfer of tuba uterina tubular conduit as a graft was statistically better in its effect on nerve regeneration than flap transfer, but also indicated that the direction of the ciliated structures had no significant effect. We believe that as this model is improved with future studies, it will shed light on new models, ideas and innovations about nerve conduits.