Superior Petrosal Vein Sacrifice during Microvascular Decompression

Objective To investigate potential effect of sacrifice of the superior petrosal vein (SPV) on postoperative complications after microvascular decompression (MVD).

Methods Retrospective review of 98 consecutive patients undergoing MVD of cranial nerve V was performed. Frequency of division of the SPV during surgery was recorded, and postoperative complications and imaging were recorded and analyzed. In patients with complications, the specific anatomic variation of the superior petrosal venous complex was noted. In addition, literature was reviewed on the sodium content on the ipsilateral cerebellum following SPV sacrifice.

Results Of 98 patients undergoing MVD, 83 (84.7%) had sacrifice of the SPV at the time of surgery, 12 (12.2%) had the SPV preserved, and 3 (3.1%) were revision operations. Four patients (4.8%) had complications deemed to be attributable to venous insufficiency or congestion. These included sigmoid sinus thrombosis with coincident cerebellar hemorrhage, midbrain and pontine infarction, hemiparesis with midbrain and pontine edema, and facial paresis with ischemia in the middle cerebellar peduncle. None of the patients with preserved SPV were symptomatic or had imaging changes consistent with venous congestion. In addition, sodium content on the ipsilateral cerebellum following SPV sacrifice occurred in the literature suggestive of edema either symptomatic or asymptomatic.

Conclusion Sacrifice of the SPV is often performed during MVD. This is associated with a complication rate that is significant in frequency and severity compared with preserving the vein. SPV sacrifice should be limited to cases where it is deemed absolutely necessary for successful cranial nerve decompression.