ABSTRACT
Objective: To investigate whether the contralateral normal external auditory canal (EAC) skin graft can maintain the ear canal health after EAC reconstruction in unilateral congenital aural atresia (CAA) cases. Methods: A Zelen design randomized controlled study was used to collect unilateral CAA patients for EAC reconstruction prospectively (clinical trial registration number: ChiCTR2000032103). The patients were randomly divided into the control group and the trial group. The trial group used the contralateral normal EAC skin graft group (transplant part of the contralateral normal EAC skin to repair the atresia side for unilateral CAA patients), the control group all used scalp blade thick skin. We observed the EAC health and hearing results of the two groups after EAC reconstruction. Results: A total of 13 cases were enrolled from July 2020 to August 2021. There were eight patients in the trial group, including six males and two females, with an average age of 22.3 years (14-36 years). There were two patients with CAA on the left and six patients on the right. The average follow-up time was 8.8 months (4-14 months). There were five patients in the control group, all cases were male with an average age of 16.2 years (12-20 years). There were four patients with CAA on the left and one patient on the right. The average follow-up time was 7.0 months (2-14 months). In the trial group, eight cases of reconstructed EAC epithelium were healthy, one patient had cicatricial stenosis of EAC opening and lateralization of the tympanic membrane. The other patient had cicatricial stenosis of reconstructed EAC, this case also had scar hyperplasia of the contralateral EAC opening but recovered after soft packing and triamcinolone acetonide injection treatment. The healthy side EAC of the rest trial group had no scarring stenosis or local bone hyperplasia during long-term follow-up. In the control group, one patient was lost to follow-up and the other four patients had dry ears of reconstructed EAC, but easily to form crusts and needed to be cleaned repeatedly, one patient had lateralization of the tympanic membrane, the EAC epithelium was not healthy for long-term follow-up. The incidence of complications related to EAC reconstruction was lower than previous studies (χ²=5.55, P=0.018), and the average postoperative Air-Bone Gap increased (18.8±10.0)dB. Conclusion: By optimizing the EAC reconstruction technology, the health of the reconstructed EAC is improved compared with the previous study. After active intervention and treatment, there should be no scarring stenosis or local bone hyperplasia on the contralateral side EAC.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Young Adult , Ear/surgery , Ear Canal/surgery , Retrospective Studies , Skin Transplantation , TympanoplastyABSTRACT
The objective of this study is to explore whether olfactory ensheathing cells (OECs) can promote the survival of newborn rat spiral ganglion cells (SGCs) and the underlying possible mechanisms. Co-culture of OECs from adult rats with SGCs from newborn rat cochlea was established and single culture of SGCs acted as control. OECs were obtained and purified based on their special rate of attachment which was different from the other harvested cell types during culture. OECs and SGCs were immunocytochemically characterized and confirmed by expression of low-affinity nerve growth factor receptor p75 or positive label of neuron-specific betaIII-tubulin. To investigate the mechanisms of the role of OECs in survival of SGCs, brain derived neurotrophic factor (BDNF) and anti-BDNF antibody (IgY) were added into the media of the co-cultures respectively, and the surviving SGCs were examined after treatment. Single layer of OECs (92% pure) was seen seven days after plating. Surviving SGCs, which extended their primary neurites, were found on the surface of the layer in the co-cultures. When OECs and SGCs were co-cultured, the number of surviving SGCs was significantly greater than that in the single culture (P<0.01). Nine days after culture, there was even no change in the number of surviving SGCs in the co-culture while the number reduced to almost zero in the single culture. In comparison with co-culture without treatment, addition of BDNF (500 pg/mL) into the media had no obvious promoting effect on the survival of SGCs. The number of surviving SGCs reduced significantly when anti-BDNF antibody was applied into the media of co-cultures (P<0.01). These results suggest that OECs can promote the survival of SGCs when they are co-cultured in vitro. BDNF released from OECs, as one of the survival factors, plays an important role in the survival of SGCs.