枕下远外侧经髁入路枕大孔区骨性标志的定量研究

Quantitative analysis of the far-lateral transcondylar approach to the foramen magnum

目的通过对成人头颅标本相关解剖进行测量和分析,为下斜坡及枕大孔区病变手术入路的选择提供依据。方法对10具(20侧)成人干颅标及10具(20侧)成人湿颅标本的枕大孔区结构及模拟远外侧经髁手术入路显露角度进行测量及分析。湿颅在模拟远外侧经髁手术入路解剖前、后均行CT扫描,从影像中获取相应解剖数据。结果干颅标本测量结果包括:枕大孔面积(7.9 cm2),长(3.7 cm),宽(3.2 cm),枕髁前后径(2.4 cm),枕髁轴径(2.6 cm),枕髁磨除前、及磨除25%、50%后所显露的术野宽度a(2.4 cm)、b(2.7 cm)、c(3.1 cm)、角度A(38.5°)、B(49.2°)、C(54.2°);湿颅解剖前后分别行CT扫描后根据影像资料所得数据包括:枕大孔面积(8.3cm2),长(3.7 cm),宽(3.3 cm),枕髁前后径(2.2 cm),枕髁轴径(2.5 cm)。枕髁磨除前、及磨除25%、50%后所显露的术野宽度a(2.6 cm)、b(2.9 cm)、c(3.3 cm)、角度A(41.5°)、B(48.8°)、C(57.6°)。湿颅数据分析结果与干颅数据分析结果相一致。结论枕下远外侧经髁入路中随着枕髁磨除范围的增加,可提供更大的术野视角;CT扫描对于术前判断术中枕髁切除程度有指导作用。

Objective Based on the measurements of skulls and quantitative analysis of correlated anatomical strueture, to provide scientific basis for the selection of operative approach to lower clivus and ventral foramen magnum. Methods Quantitative analysis of foramen magnum surgical exposures was performed on 10 skulls （20 sides ） and 10 cadaveric dissection （20 sides）. Computed tomographie（CT） scans were performed on eadaveric heads before and after condylar resections. Results Skull measurements includes the foramen magnum area（7.9 cm^2）, length （ 3.7 cm）, width （3.2 cm）, anteroposterior condylar length （ 2.4 cm） , axial condylar length （ 2.6 cm ）. Mean widths of potential surgical exposures for skulls were obtained for a suboeeipital craniotomy（2.4cm）, b with 25% （2.7 cm）, and e 50% condylar resection（3, lem）. Mean angles of exposure were as follows ： A （ 38.5° ）, B （49.2° ）, C （ 54.2 °）. Cadaverie dissection measurements includes the foramen magnum area （ 8.3 cm^2／）, length （ 3.7 cm） , width （ 3.3 cm） , anteroposterior condylar length （ 2.2 cm） , axial condylar length （ 2.5 cm） , Mean widths of potential surgical exposures for skulls were obtained for a snboeeipital eraniotomy（2.6cm） , b with 25% （2.9cm）, and c 50% condylar resection （3.3cm）. Mean angles of exposure were as follows ： A （ 41.5°） , B （ 48.8 °） , C （ 57.6° ）. CT scans of eadaverie heads yielded measurements equivalent to measurements found on the dry skulls. Conclusion Partial resection of condylar on far - lateral transeondylar approach to the foramen magnum will offer a wider exposing angle. Measurements of CT images can be used preoperatively to help analyze the need for condylar resection and intraoperatively to guide the extent of condylar resection.