乙状窦后经内耳门上人路颞骨岩部切除的量化研究

目的 研究乙状窦后经内耳门上人路(RSSMA)的安全性、可行性. 方法 将成人颅骨标本10例和湿标本18例的颢骨岩部行螺旋CT三维扫描.层厚均为1 mm.按改良乙状窦后人路技术开颅,以不损伤三叉神经、面听神经为原则切除内耳门上结节、岩尖,再在此基础上以显露总脚、水平半规管为下界向侧方磨除颞骨岩部.直到本人路可显露的最侧方点(FLM).采用CT和手工测量相结合.以内耳门的外上唇(SLIAM)作为测量的标志点,测量SLIAM到基底、总脚、前庭的距离,并计算内耳门上结节和岩尖各方向的切除率. 结果 岩尖的切除率按上下径、前后径、左右径递增,分别是(26±6)%、(45±5)%、(72±6)%.内耳门上结节的切除率上下径为(69±10)%,前后径、左右径均为100%.颈内动脉虹吸部段岩尖可切除率是(44±7)%.本人路SLIAM到FLM的距离始终大于SLIAM到前庭、总脚、内耳门基底的距离.SLIAM到FLM、前庭、总脚、内耳门基底距离分别为(17.6±2.0)mm、(10.1±1.4)mm、(10.4±1.5)mm、(10.6±1.1)mm. 结论 RSSMA切除岩尖时不易伤及颈内动脉虹吸部;其最侧方缘始终在前庭、内耳门基底、总脚的外侧,在向侧方扩大切除颞骨岩部时要避免前庭、半规管和总脚的损伤.

Quantitative study of the retrosigmoid suprameatal approach for petrous apex resection LI

Objective To evaluate the safety and feasibility of the retrosigmoid suprameatal approach (RSSMA) for petrous apex resection. Methods Ten human dry skull and 18 cadaverie skull specimens were collected and 3-dimensional CT scanning was performed with slice thickness of 1 mm. Craniotomy was performed on the specimens through a modified retrosigmoid approach, and the suprameatal tubercle (ST) and petrous apex (PA) were removed without damaging the trigerninal and facial nerves. The petrous bone was resected to the farthest lateral margin (FLM) that the approach could allow. CT-based and manual measurements were used to determine the lateral-middle line, superior-inferior, anterior-posterior lengths of the ST and PA. The superolateral lip of the internal auditory meatus (SLIAM) was defined as the landmarks for the measurement, and the distances from the SLIAM to the fundus, the common crus, and vestibule was determined. Results From thesuperior-inferior to the anterior-posterior and median-lateral directions, the resection rate of the PA increased to (26.6±6)%, (45±5)%, and (72±6)%, and the rate for the ST to (69±10)%, 100%, and 100%, respectively. The resection rate of the PA at the siphonal portion was (44±7)%. In the RSSMA, the distance from the SLIAM to the FLM (17.6±2.0 mm) was greater than the distances from the SLIAM to the vestibule (10.1±1.4 mm), the fundus (10.4±1.5 mm), and the common crus (10.6±1.1 mm). Conclusions The RSSMA may well protect the siphonal portion of the internal carotid artery from damages in PA resection. The FLM of the RSSMA is always lateral to the vestibule and the fundus of the internal auditory canal and the common crus, and therefore injuries to the vestibule, the semicircular canal and the common crus should be avoided.