Skull Base Surgery of the Posterior Fossa

73

(Table 5.2). The basic far lateral exposure may
often be sufficient to access lesions along the
anterolateral margin of the foramen magnum.
The greatest gain in visualization is obtained
with removal of the jugular tubercle [ 4 ], and the
risk of injury to cranial nerves and the jugular
bulb in carrying out this step may be justified in

some cases. Posterior partial condylectomy

increases visualization to only a small extent, but

provides much improved freedom for surgical

manipulation; this step can be performed with

relatively low morbidity [ 5 ].

References

1. Fine AD, Cardoso A, Rhoton AL Jr. Microsurgical
   anatomy of the extracranial-extradural origin of the
   posterior inferior cerebellar artery. J Neurosurg.
   1999;91(4):645–52.


2. Wen HT, Rhoton AL Jr, Katsuta T, de Oliveira
   E. Microsurgical anatomy of the transcondylar, supra-
   condylar, and paracondylar extensions of the far-
   lateral approach. J Neurosurg. 1997;87(4):555–85.


3. Vishteh AG, Crawford NR, Melton MS, Spetzler RF,
   Sonntag VK, Dickman CA. Stability of the craniover-
   tebral junction after unilateral occipital condyle resec-
   tion: a biomechanical study. J Neurosurg. 1999;90(1
   Suppl):91–8.


4. Spektor S, Anderson GJ, McMenomey SO, Horgan
   MA, Kellogg JX, Delashaw JB Jr. Quantitative
   description of the far-lateral transcondylar transtuber-
   cular approach to the foramen magnum and clivus.
   J Neurosurg. 2000;92(5):824–31.


5. Bertalanffy H, Seeger W. The dorsolateral, suboc-
   cipital, transcondylar approach to the lower clivus
   and anterior portion of the craniocervical junction.
   Neurosurgery. 1991;29(6):815–21.

Fig. 5.8 Intradural exposure achieved with the far lateral
approach. (a) The dural flap is retracted laterally to ensure
the widest exposure is maintained. Note the low profile of
the dural base achieved by the extradural bone removal.

(b) The far lateral approach provides access to pathology

such as a VA-PICA aneurysm. Dural penetration of verte-

bral artery ( 1 ), upper rootlets of hypoglossal nerve ( 2 ),

spinal accessory nerve ( 3 ), aneurysm at PICA origin ( 4 )

Table 5.2 Summary of the exposure obtained with vari-
ants of the far lateral approach

Approach Indications

Basic far lateral Lateral/anterolateral foramen

magnum

Transcondylar

Occipito-

transcondylar

Lower clivus, pre-medullary

space

Atlanto-occipital Vertebral artery at dural ring

Complete

transcondylar

Anterior foramen magnum

Supracondylar

Hypoglossal canal Lateral lower clivus

Transtubercular Pre-pontomedullary space,

high PICA origin

Paracondylar

Transjugular Posterior jugular bulb

Transmastoid Presigmoid dura, mastoid

segment of facial nerve

5 Far Lateral Approach and Its Variants