Abstract
Introduction: Standard approaches to the craniocervical junction (CCJ) includes the midline posterior approach and the transoral approach. Both of them are limited laterally because of the Vertebral Artery (VA). Lateral approaches in which the VA is controlled and sometimes mobilized or transposed have been developed to reach the lateral corner of the CCJ. The surgical technique and personal experience are presented.
Methods: From our experience in the VA surgical exposure, we developed since 1980 two lateral approaches directed towards the CCJ: the posterolateral and the anterolateral approach. The posterolateral approach is a lateral extension of the midline posterior approach with control of the VA above the arch of atlas and opening of the CCJ up to the VA. Minimal drilling of the arch of atlas and occipital condyle is realized. It is mostly applied on intradural tumors but also in some extradural posterolateral lesions.
The anterolateral approach is a superior extension of the lateral approach used to control the VA from the C6 to C2 levels. The field is opened between the sternomastoïd muscle and the internal jugular vein. Then the VA is exposed between C1 and C2 transverse processes and above C1. It is essentially applied on extradural and bony lesions around the CCJ.
Experience: Posterolateral approach was applied on 109 tumors, mostly meningiomas (N=78) and neurinomas (N=22) and 4 bony malformations compressing the VA or the neuraxis. Excellent results were obtained with complete tumoral resection (Simpson grade I or II for meningioma) with only one case of worsening of the neurological condition and two cases with stabilization.
Anterolateral approach was used on 139 patients with different types of tumors including neuromeningeal tumors N=36, primary bone tumors N=51, sarcoma N=16 and others types N=21, and on 3 cases of VA compression by bone malformations. Satisfying tumoral resection could be achieved in almost all cases. Sacrifice of the VA was deliberately realized in 5 patients to ensure as radical a resection as possible in case of malignant tumors or chordomas.
There was no mortality in this series. Morbidity is very limited; injury of the VA was observed in two cases in which repair of the vessel could be done successfully. Stretching of the XI nerve was the cause of pain along the trapezius muscle in 5 patients.
Conclusion: Lateral approach to the CCJ can be realized through two different axis of work: the posterolateral and the anterolateral approach. These approaches gives very nice and safe access to the lateral aspect of the CCJ. They complete the other approaches to the CCJ and may be used in association with them.
The abstracts were prepared by Dr Robert Moore. Correspondence should be addressed to him at Spine Society of Australia, c/o the Adelaide Centre for Spinal Research, Institute of Medical and Veterinary Science, PO Box 14, Rundle Mall, Adelaide SA 500, Australia.
