Impact of cartilage graft size on success of tympanoplasty

Abstract Introduction: In the last decade, there has been an increasing use of cartilage grafts in the primary repair of tympanic membrane perforations. The major advantages of cartilage are its stiffness and its very low metabolic requirements, which make it particularly suitable for difficult conditions, such as subtotal perforations, adhesive otitis and reoperation. Objective: To analyze the impact of different perforation sizes requiring different sizes of cartilage on the anatomical and functional outcome after tympanoplasty. Methods: Through this prospective non-controlled, non-randomized study, 50 patients underwent cartilage type 1 tympanoplasty (20 females and 30 males), with a mean age of 19.3 ± 9.8 years. According to size of perforation, patients were subdivided into three groups, Group I had perforation >50% of tympanic membrane area, in Group II patients the perforations were 25-50% of tympanic membrane area, and in Group III the perforations were ≤25% of tympanic membrane. All patients had pre and postoperative Pure Tone Average and Air Bone Gap frequencies (0.5, 1, 2, 4 kHz). All patients were followed up at least 12 months after operation. Results: The anatomical success rate among all patients was 92%, all groups showed statistical significant improvement between pre and postoperative air bone gap, no significant correlation between size of cartilage graft and degree of air bone gap improvement was noticed among the three groups. Conclusion: Size of a cartilage graft has no impact on degree of hearing improvement or anatomical success rate after tympanoplasty.

摘要 引言：近十年来，软骨移植物（cartilage grafts）在鼓膜穿孔（tympanic membrane perforations）初次修复中的应用日益增多。软骨的主要优势在于其刚度及极低的代谢需求，使其特别适用于难治性病例，如次全穿孔、粘连性中耳炎（adhesive otitis）以及再次手术患者。
研究目的：分析不同大小的鼓膜穿孔（需匹配对应尺寸的软骨移植物）对鼓室成形术（tympanoplasty）术后解剖学结局与功能学结局的影响。
研究方法：本研究为前瞻性非对照、非随机化研究，共纳入50例行Ⅰ型软骨鼓室成形术的患者（女性20例，男性30例），平均年龄为19.3±9.8岁。根据穿孔面积将患者分为三组：Ⅰ组穿孔面积＞50%鼓膜总面积，Ⅱ组穿孔面积为25%~50%鼓膜总面积，Ⅲ组穿孔面积≤25%鼓膜总面积。所有患者术前及术后均接受纯音平均听阈（Pure Tone Average）及气骨导差（Air Bone Gap）检测，检测频率为0.5、1、2、4 kHz。所有患者术后随访至少12个月。
研究结果：所有患者的解剖学成功率为92%；三组患者术前与术后的气骨导差均存在统计学意义的改善；三组中未观察到软骨移植物尺寸与气骨导差改善程度存在显著相关性。
研究结论：软骨移植物尺寸对鼓室成形术后的听力改善程度及解剖学成功率均无影响。