Abstract
Background Endoscopic microvascular decompression (MVD) offers reliable identification of neurovascular
conflicts under superb illumination, and it provides minimally invasive surgery for
trigeminal neuralgia and hemifacial spasm. Transposition techniques have been reported
as a decompression method to prevent adhesion and granuloma formation around decompression
sites, providing better surgical outcomes. The feasibility and effects of transposition
under endoscopic MVD were evaluated.
Material and Methods Fully endoscopic MVD was performed using 4-mm 0- and 30-degree endoscopes. The endoscope
was fixed with a pneumatic holding system, and a bimanual technique using single-shaft
instruments was performed. Transposition was performed with Teflon felt string and
fibrin glue. Surgical results were evaluated using the scoring system proposed by
Kondo et al.
Results The endoscope was introduced via a retrosigmoid keyhole. The 0-degree endoscope was
advanced through the lateral aspect of the cerebellar tentorial surface to the trigeminal
nerve in cases of trigeminal neuralgia and through the petrosal surface of the cerebellum
to the facial nerve in cases of hemifacial spasm. Neurovascular conflicts and perforators
from the offending artery were clearly demonstrated under the 30-degree endoscopic
view, and transposition of the offending artery was safely performed with preservation
of perforators. Clinical symptoms improved without permanent complications.
Conclusion Endoscopic MVD with the transposition technique is feasible. Superb endoscopic views
demonstrate perforators arising from the offending artery behind the corner, allowing
damage to perforators to be avoided during the transposition technique. Endoscopic
MVD using the transposition technique is expected to offer excellent surgical results.
Keywords
endoscopic keyhole surgery - posterior skull base - retrosigmoid approach - root entry/exit
zone
