带孔钛环外支撑游离皮片重建气管缺损的动物实验

目的 探讨带孔钛环外支撑游离皮片重建颈段气管缺损的可行性.方法 12只成年杂种犬随机均分为两组.实验组切除颈段气管前壁、侧壁约2/3周径,长约25 mm(4个气管环),制作人工气管缺损模型,取腹部全厚游离皮片修复气管缺损,皮片外部由带孔钛环悬吊支撑.对照组手术模型及缺损修复与实验组相同,但未放置钛环.术后1个月及6个月行X线及纤维支气管镜检查,观察钛环固定情况及管腔情况.术后6个月处死动物,病理检查移植物组织学变化.结果 实验组动物1只术后第5天出现伤口感染裂开,皮片坏死,钛环脱落排出,予以处死;其余5只存活,无呼吸困难;X线摄片示气管腔通畅,钛环固定良好,无移位、变形;纤维支气管镜检查见管腔通畅,管壁光滑,未见狭窄、挛缩及坏死,其中1只在远心端吻合口有少量肉芽,不影响呼吸.存活动物术后6个月处死后病理检查示移植皮片表面大部分覆盖假复层柱状上皮,但上皮覆盖不连续;未见到毛囊,毛发等皮肤附件结构.3只对照组动物术后24 h内死于窒息,尸检发现管腔塌陷皮片水肿;另外3只术后出现不同程度的呼吸困难,最长存活16 d,术后14 d纤维支气管镜检查示管腔塌陷狭窄.结论 带孔钛环可重建气管支架,游离皮片可作为气管黏膜替代物,是气管重建的简便方法之一.

Experimental study on tracheal reconstruction using porous titanium rings and free skin flap

OBJECTIVE: To investigate the feasibility and efficacy of the cervical tracheal reconstruction using porous titanium rings and free skin flap. METHODS: Twelve adult mongrel dogs were divided randomly into group I and group lI. A segment of cervical trachea (25 mm, 4 rings, about 2/3 circumference) was resected and a rectangular free skin flap was harvested from abdomen. The flap was sutured to the defect part and supported with two porous titanium rings (group I) or without (group II ). X ray and fiberscopic examinations were performed at the end of the first and the sixth months postoperatively. After six months the dogs were sacrificed and the grafts were examined macroscopically and microscopically. RESULTS: In group I, one dog was sacrificed for wound infection and skin flap necrosis with defluxion of titanium rings in the fifth day postoperatively. The other 5 of 6 survived until the end of six months. X-ray examination showed titanium rings were fastened well without displacement or deformity. Through fiberscopy, the trachea luminal patency was maintained well without stricture, shrinkage or necrosis. Histologic examination showed most of the inner surface of the flap was covered with ciliated columnar epithelium. In group II, 3 of 6 dogs died of suffocation within 24 hours postoporatively. The remaining 3 dogs survived from 7 to 16 days with dyspnea and fiberscopic examination showed narrowed trachea lumens. CONCLUSIONS: Porous titanium rings could recreate the framework for cervical tracheal reconstruction using free skin flap and would be one of the options for tracheal reconstruction.