ObjectiveEndoscopic tympanoplasty includes various surgical methods, including internal repair, interlayer repair, and external overlay. This technique requires autologous materials, allografts, and xenografts, which are used to repair tympanic membrane (TM) perforation. To obtain good results, appropriate surgical methods and repair materials should be selected. In this study, we aimed to assess the efficacy of repairing refractory TM perforations in the porcine small intestinal submucosa (SIS) during transcanal endoscopic type I tympanoplasty, focusing on wound healing rates and hearing improvement. MethodA retrospective chart review was performed on patients who underwent TM perforation repair with porcine SIS and tragus cartilage between January 2022 and September 2022 at Sir Run Run Shaw Hospital, Zhejiang University School of Medicine (Hangzhou, China). We considered perforation size, tympanic status, pre- and postoperative symptoms, follow-up data, wound healing rates, and hearing improvement. ResultsOf the 115 patients included in the study, 56 underwent interlayer repair with porcine SIS of the TM, and 59 patients underwent internal repair with tragus cartilage. No significant difference was found between the two groups at baseline in terms of age, sex, disease course, perforation side, tympanic status, underlying disease, or preoperative infection. The total postoperative effective rate of interlayer implantation with porcine SIS was 91.07% (51 patients), and that of internal implantation with tragus cartilage was 88.14% (52 patients). No significant difference was found in terms of the graft success rate between the two surgical methods (p = 0.887). Postoperative pure tone auditory (PTA) and air-bone gap (ABG) density significantly increased in both groups compared with before surgery (p < 0.05). However, the postoperative PTA and ABG density were not significantly different three months post-surgery between the two groups (p > 0.05). Compared to those in the internal implantation group, the patients in the interlayer group had a shorter operation duration (51.36 ± 6.76 min vs. 59.71 ± 7.45 min, t = 6.298, p < 0.001) and less blood loss (11.91 ± 2.61 mL vs. 15.27 ± 2.57 mL, t = 7.019, p < 0.001). ConclusionsOur study findings suggest that the closure of irreversible TM perforation by interlayer implantation using an interposition xenograft derived from porcine SIS produces favorable outcomes compared with those of inner tragus cartilage repair using the TM. This method offers distinct advantages, including the absence of donor-site morbidity, ease of graft modification and manipulation, and superior cosmetic results.