Surgical Treatment for Vertebral Artery and Posterior Inferior Cerebellar Artery Aneurysms Via Transcondylar Approach or Transcondylar Fossa Approach

Yang, Na rae; Seo, Eui Kyo

Abstract

OBJECTIVE
Since posterior circulation vascular lesions are adjacent to important structures such as the brain stem and lower cranial nerves, the acquisition of anatomical information and the careful selection of approaches are essential for the surgical treatment of these lesions. We examined the characteristics and the indications of the far lateral suboccipital approach which exposes lesions without retraction of the brain stem for the treatment of either a vertebral artery (VA) or posterior inferior cerebellar artery (PICA) aneurysm. We present the best diagnostic tool to determine the approaches.
METHODS
We have reviewed 11 patients who received surgical treatments between 2005 and 2011 for VA or PICA aneurysms. All of the patients had 3-dimensional computed tomography (3DCT) angiography performed to investigate the relation of the location between the aneurysm and hypoglossal canal.
RESULTS
Eight of the 11 patients were treated with the transcondylar fossa approach (TCFA) as their lesions were located proximal to the hypoglossal canal, while three were treated with the transcondylar approach (TCA) as their lesions were located distal to the hypoglossal canal. Of the three patients treated with the TCA, one had temporary palsy of the 11th cranial nerve and the others recovered without any neurological defects. 3DCT angiography showed the relation of the location between the aneurysm and hypoglossal canal.
CONCLUSION
The TCFA and TCA are good approaches to expose lesions without retraction of the brain stem. To determine the approaches for the surgery of VA or PICA aneurysms, using 3DCT before surgery is advantageous in understanding the positional relations between the hypoglossal canal and the lesions. During the actual surgery, the posterior condylar canal through which the posterior condylar emissary vein passes can be used as an anatomical landmark for TCFA. With this approach, craniocervical instability can be avoided.