REVIEW ARTICLES   

Journal of Neurosurgical Sciences 2003 December;47(4):183-7

Copyright © 2004 EDIZIONI MINERVA MEDICA

lingua: Inglese

A vertebral artery tortuous course below the posterior arch of the atlas (without passing through the transverse foramen). Anatomical report and clinical significance

Jian F. Z. ^{1, 2}, Santoro A. ², Wang X. W. ¹, Passacantili E. ², Seferi A. ², Liu S. S. ¹

¹ Department of Neurosurgery, Beijing Hospital, Beijing, China 2 Department of Neurological Sciences Division of Neurosurgery University of Rome “La Sapienza”, Rome, Italy

A ver­te­bral ­artery (VA) cours­ing ­below the pos­te­ri­or ­arch of the ­atlas (C1) with­out pass­ing ­through the trans­verse fora­men of C1, com­bined ­with a tor­tu­ous ­course with­in the spi­nal ­canal has rare­ly ­been report­ed in the lit­er­a­ture. This arti­cle ­describes a ­case encoun­tered dur­ing an ana­tom­i­cal ­study of the far-lat­er­al ­approach, and ­reviews its embryon­ic devel­op­ment and clin­i­cal sig­nif­i­cance. The sub­oc­cip­i­tal tri­an­gle was ­filled ­with numer­ous ­venous plex­ures. After exit­ing ­from the trans­verse fora­men of C2, ­instead of pass­ing ­upwards ­through the trans­verse fora­men of C1, the VA ­turned direct­ly medi­al­ly ­towards the spi­nal ­canal. At the spi­nal ­canal, it ­first ­formed an ­angle down­wards, ­then ­turned ­upwards, pierc­ing and enter­ing the lat­er­al ­part of the ­dura at C1 lev­el. The diam­e­ter of ­this VA ­seemed to be with­in its nor­mal lim­its. The ­course of the con­tra­lat­er­al (­right) VA was nor­mal but ­with a ­small cal­i­ber and main­ly sup­plied the pos­te­ri­or infe­ri­or cer­e­bel­lar ­artery (­PICA); ­after ­PICA, it ­became ­much thin­ner and dys­plas­tic, the bas­i­lar ­artery was main­ly sup­plied by the ­left VA. The bilat­er­al pos­te­ri­or com­mu­ni­cat­ing arter­ies ­were ­large in diam­e­ter but ­there was dys­pla­sia of the P1 seg­ment of the pos­te­ri­or cere­bral arter­ies bilat­er­al­ly. Marked tor­tu­os­ity of the bilat­er­al intra­ca­ver­nous inter­nal carot­id ­artery (ICA) was ­also ­found. We did not ­find any ­osseous abnor­mal­ity in the occi­pi­to-­axial ­region or of C1-C2 ­joint. An abnor­mal ­course of the VA ­should be ­kept in ­mind dur­ing expo­sure of the cra­ni­o­cer­vi­cal junc­tion, espe­cial­ly in the varie­ty of lat­er­al approach­es; due to com­pres­sion of the ­nerve ­roots or the spi­nal ­cord, ­this abnor­mal ­course of the VA ­could ­give ­rise to clin­i­cal symp­toms, ­which ­could be ­resolved by micro­vas­cu­lar decom­pres­sion tech­nique.