Evaluation of human acellular amniotic membrane for promoting anterior auricle reconstruction.

Abstract

The excision of the lesions on the outer ears has been broadly conducted in the department of dermatology because the ear is a region with a relatively high prevalence of cutaneous tumors.1 As important cosmetic units, well postoperative recovery of the outer ears plays a vital role in not only the aesthetic but also functional outcomes. However, the special structure of the auricle, especially the anterior part, brings the dermatological surgeon great difficulty in suturing and dressing the wound. Therefore, it is of great benefit to find an approach that does well in both simplifying surgical procedures and wound healing. The Human acellular amniotic membrane (HAAM) has been widely applied in conditions of skin defect. It works as a scaffold for transferring cells to the wounds after procedures of decellularization.2, 3 In the previous study, we have implanted the HAAM to the defects on the lower third nasal, combined with second-intention healing, and that yield a satisfactory effect.4 Analogously, the HAAM may also represent an alternative strategy for auricular skin defects, yet none of the hypotheses is available in evidence-based publications. Hence, we aimed at evaluating the feasibility of HAAM as an effective alternative for the auricle. The study was approved by the institutional review board, all included follow-up data had been authorized by the patients with informed consent. This was a retrospective case-control study of 36 adult patients admitted to Sichuan University West China Hospital from 1 September 2016, to 1 July 2021, all of them underwent second-intention healing of full-thickness auricular skin defects after benign tumor removal. All surgeries were performed by the authors. Patient data were collected on duration time of pain (pain appears for the first time until it disappears after surgery), haemostatic time (no bleeding was observed when changing the dressing), time of scab formation and detachment, the healing outcomes (the diameter interval from residual skin defect when removal, to the scar one month later; Figure S1). All variables have been divided into two groups based on whether the diameter of the skin defects is less than 5 mm. Of the patients aged 19–64 years (21 female and 15 male), half of the individuals have applied HAAM plus Vaseline gauze treatments (HAAM group), the same number as the control group (Vaseline gauze treatment only). Variables were compared using Fisher's exact, Student's t and Wilcoxon-Mann-Whitney tests where appropriate. p value < 0.05 was thought of statistical significance (Table 1). In contrast with the control group, the application of HAAM resulted in a shorter duration of pain, as did haemostatic time for the diameter of skin defect <5 mm; furthermore, it improved scab detachment and wound healing for skin defect diameter ≥5 mm (p < 0.05). Of note, the HAAM enhanced the wound healing markedly when the diameter of the defect ≥5 mm was consistent with our previous results of lower third nasal reconstruction. Regarding postoperative complications, two patients from the control group experienced hypertrophic scar and one patient encountered infection within a 3-month follow-up period. Numerous surgical possibilities following the removal of auricular lesions have been proposed, including split-thickness skin and reversed dermal graft, which requires donor sites and generally is used in large defects ≥2 cm in size. These grafts can achieve primary closure after a series of complicated procedures, whereas they may be associated with some limitations such as time-consuming, expanded trauma and patients' complaint. And the second-intention healing has been applied in small full-thickness auricular skin defects but linked with some unacceptable results.5 As a booming skin alternative, the scope of HAAM application should be carefully evaluated. Limitations of the research consist of retrospective design and small sample size. The authors have declared no conflicting interests. YSC performed the research and wrote the paper. LL analysed the data. SLX designed the research study and revised the paper. The authors thank Dr Qiong Lyu (Department of Oncology, Zhujiang Hospital, Southern Medical University, Guang Zhou, China) for her support in statistics. The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.