改良部分迷路切除岩骨尖入路的岩骨磨除技术

目的探讨改良部分迷路切除岩骨尖入路(PLPA)的岩骨磨除技术。方法测量10例(20侧)成人干颅骨标本骨性结构间的距离;对15例(30侧)成人尸头采用PLPA及改良PLPA暴露岩斜区,观察岩斜区解剖结构的暴露情况及有无岩骨内重要结构的损伤,测量骨窗大小及增加的视野、视角,对结果进行统计学分析。结果岩浅大神经沟到岩骨嵴的平均距离为12.8m m,D onaldson线到岩骨嵴的平均距离为12.2m m,所有标本均未损伤岩骨段颈内动脉等重要结构。改良PLPA可充分暴露岩斜区。改良PLPA较PLPA骨窗小,差异有高度统计学意义(P<0.01);磨除骨质后两入路增加的手术视野和视角无统计学差异(P>0.05)。结论改良PLPA较PLPA创伤小,暴露同样充分。岩骨磨除操作是改良PLPA的关键技术,不容易损伤岩骨内重要结构,有可能保留听力;D onaldson线可作为磨除岩骨的安全界限。

Abrasion of the petrous bone via a modified partial labyrinthectomy petrous apicectomy approach

Objective To probe abrasion technique of the petrous bone via modified partial labyrinthectomy petrous apicectomy (PLPA) approach. Methods The distance between the osseous structures was measured on 10 dry skulls (20 sides). Bilateral stepwise dissections were performed to expose the petroclival region on 15 cadaveric heads (30 sides) by the ordinary and the modified PLPA approach. The petroclival region was exposed and the injury to the intrapetrous important structures observed and assessed. The size of bone window, and the increased visual field and angle were measured and statistically analyzed after the partial labyrinthectomy and the petrous apicectomy. Results The average distance between the petrous ridge and the groove of the greater petrosal nerve was 12.8 mm, and average distance between the petrous ridge and Donaldson's line 12.2 mm. The important anatomic structures in the petrous bone such as the facial canal and the petrous carotid artery were not injured in all the specimen. The modified PLPA approach provided wide and sufficient exposure to the petroclival region. The modified PLPA approach showed smaller bone window compared with the conventional PLPA approach (P < 0.01). The difference in surgical visual field and angle were statistically insignificant between two approaches (P > 0.05). Conclusions The modified PLPA approach lead less surgical injury and provide the same exposure to the petroclival region compared with the conventional PLPA approach. Abrading the petrous bone was the key technique in the modified PLPA approach via which the important intrapetrous anatomic structures were not easily injured, and hearing may be preserved. Donaldson's line can be used as the safe limit during the abrading period of the petrous bone.