Abstract
Background Surgery for petroclival tumors is very challenging for neurosurgeons because the
position of the tumor in relation to the brainstem, cranial nerves, and posterior
fossa vessels greatly restricts the surgical field. Some papers have described using
sigmoid sinus ligation to open the surgical field; however, pre- and intraoperative
evaluations of the safety of ligation have been limited, despite the risk of complications
from venous insufficiency. Here, we describe our method of preoperatively evaluating
the potential safety of a retrolabyrinthine transsigmoid approach with nondominant
ipsilateral sigmoid sinus ligation (RLTSwSSL).
Methods A retrospective review was conducted on petroclival tumors treated over a 5-year
period with RLTSwSSL after evaluation with both an endovascular balloon occlusion
test (BOT) and an open-field sinus clipping occlusion test (COT). Changes in pressure
of < 10 mm Hg and the absence of neurodegeneration during the tests indicated that
it would be safe to proceed with permanent ligation.
Results Four patients with large petroclival tumors underwent surgery via RLTSwSSL after
detailed preoperative evaluations with both BOT and COT. All patients had uneventful
courses of recovery without developing any complications derived from venous insufficiency.
Conclusion In our case series, we have described a protocol for using both BOT and COT to evaluate
the likely outcomes after sigmoid sinus ligation and thereby to improve safety. Further
studies are needed to establish definite criteria for both occlusion tests that will
ensure good outcomes.
Keywords balloon occlusion test - sinus ligation - skull base surgery - open-field occlusion
test
