B. Vallee et al., THE CLOSE MEDIO-CONDYLAR OR TRANS-CONDYLA R LATERAL EXTENSION OF THE POSTERIOR SUBOCCIPITAL APPROACH - ANATOMICAL STUDY AND SURGICAL CONSIDERATIONS, Neuro-chirurgie, 39(6), 1993, pp. 348-359
In order to improve the surgical approach to tumors and aneurysms of t
he anterior or antero-lateral aspect of the foramen magnum, some autho
rs have proposed a lateral extension of the posterior sub-occipital ap
proach to the occipital condyle including in some cases its partial or
complete resection. The evaluation of this close medio-condylar or tr
ans-condylar suboccipital approach has been performed on eight coloure
d-latex injected specimens in the conditions of a microsurgical operat
ion. The extra- and intradural steps have been studied so as to define
the optimal position of the patient's head and the surgeon and to pre
cise the accessible anatomical structures : Vertebral artery (and its
control), Cranial nerves IX, X, XI & XII, Postero-inferior cerebellar
artery and collaterals, Vertebro-basilar junction, antero-lateral aspe
ct of the brain stem and spinal cord. Depending on the extent of the c
ondylar resection, the lateral extension of the posterior sub-occipita
l approach may be defined as minimal, moderate or large. Based on anat
omical and surgical constatations it appears that a complete resection
of the occipital condyle (resulting in occipito-cervical instability)
should be reserved for those very extensive lesions. Yet a partial dr
illing of the condyle provides a better angle of approach, minimises t
he hazards of retraction of nervous structures and enables the surgeon
to take the best advantage of the dissection and control of the verte
bral artery.