Microsurgical anatomy of the transcondylar, supracondylar, and paracondylar extensions of the far-lateral approach

Abstract

Despite a large number of reports of the use of the far-lateral approach, some of the basic detail that is important in safely completing this exposure has not been defined or remains poorly understood. The basic far-lateral exposure provides access for the following approaches: 1) the transcondylar approach directed through the occipital condyle or the adjoining portions of the occipital and atlantal condyles; 2) the supracondylar approach directed through the area above the occipital condyle; and 3) the paracondylar exposure directed through the area lateral to the occipital condyle. The transcondylar approach provides access to the lower clivus and premedullary area. The supracondylar approach provides access to the region of, and medial to, the hypoglossal canal and jugular tubercle. The paracondylar approach, which includes drilling of the jugular process of the occipital bone in the area lateral to the occipital condyle, provides access to the posterior portion of the jugular foramen and to the mastoid on the lateral side of the jugular foramen. In this study, the anatomy important to completing the far-lateral approach and these modifications was examined in 12 cadaveric specimens. In the standard posterior and posterolateral approaches, an understanding of the individual suboccipital muscles is not essential. However, these muscles provide important landmarks for the far-lateral approach and its modifications. Other important considerations include the relationship of the occipital condyle to the foramen magnum, hypoglossal canal, jugular tubercle, the jugular process of the occipital bone, the mastoid, and the facial canal. These and other relationships important to completing these exposures were examined in this study.

Surgical Experience With Skull Base Approaches for Foramen Magnum Meningioma.

“…13) We encountered complications in our earlier approaches for anterior foramen magnum meningioma, such as additional lower cranial nerve injury, systemic and local infections, CSF leakage, and even one case of postoperative mortality. We subsequently used the transcondylar approach based on several microsurgical anatomy cadaver studies of this complex region, descriptions of condyle drilling in cadaver studies, 1,9,30,31) recent technical advances in skull base surgery for anteriorly located meningiomas, and some outstanding clinical studies on partial condylectomy. 5,15,27) The transcondylar approach provides a lateral perspective for tumor removal, and is an evolution of the lateral approaches to the posterior fossa.…”

Far-lateral transcondylar approach: surgical technique and its application in neurenteric cysts of the cervicomedullary junction

“…In some cases, the posterior spinal artery and posterior inferior cerebellar artery can arise extradurally and can potentially be injured. 25,34 Subperiosteal dissection of the VA from the vertebral groove reduces bleeding from the venous plexus by leaving the periosteal sheath around the artery intact. 19 The atlantooccipital membrane is sharply divided to expose the underlying dura mater.…”

The Anatomy of Occipital Condyles and Foramen Magnum and Their Surgical Importance: A Morphometric Study

“…The dimensions of foramen magnum and the axial length of occipital condyles are very important for surgical exposure, such as in cases of tumor resection from foramen magnum area [2][3][4]. Space occupying lesions ventral to the spinal canal at the level of foramen magnum can be reached using a ventral or dorsal approach [5]. As the ventral approach is dangerous and has a high rate of morbidity, the dorsal approach is preferred to reach the space occupying lesion ventral to spinal cord at the craniovertebral junction [6,7].…”