Safety Ranges in V3 Segment of the Vertebral Artery for Surgical Procedures at the Craniocervical Junction

摘要

The aim of this study was to establish safety ranges for the third vertebral artery segment (V3) for craneocervical procedures. Injury to V3 represents a potentially catastrophic complication. Its tortuous path and complex relationship with neighboring structures, increasing the risk. Ten male adult cadavers (20 vertebral arteries) with arterial infiltration of red latex were studied. The length, angles and anatomical measurements were obtained between the selected surgical landmarks and the portions of V3 segment. The horizontal portion has a length of 32.7 +/- 3.6 mm with an angulation of 115.1 +/- 8.3 degrees. The mean distances of the horizontal portion were: from the midline to the V3 groove of C1 posterior arch (24.7 +/- 6.3 mm); from C1 pars interarticularis to the V3 distal loop of V3 (8.9 +/- 1.4 mm). The vertical portion has a length 32.5 +/- 5.6 mm with an angulation of the proximal loop of 113.6 +/- 5.8 degrees. The mean distances between the C2 spinous process to the medial surface of the distal loop (43.8 +/- 4.2 mm); from the C1-C2 joint to the V3 vertical portion (9.5 +/- 1.5 mm); from C2 pars interarticularis to V3 in the C2 transverse foramen (6.5 +/- 3.4 nun); from C2 pars interarticularis to V3 in the C1 transverse foramen (17.5 +/- 4.5 nun). We reported four potential sites where V3 can be injured during four different surgical procedures: exposure of the posterior arch of Cl, and pars interarticularis of C1 in the horizontal portion and exposure of the C1-C2 joint, and placement of C1-C2 transarticular screws one in the vertical portion. We provide measurements of redundancy and safety ranges to reduce the risk of injury to the V3 segment during craniocervical surgical procedures.