PMC4756247_01
A: At redo microvascular decompression, the posterior inferior cerebellar artery (arrows) that had compressed the root exit zone of the facial nerve at the first microvascular decompression remained transposed. B: The facial nerve (CN VII) was compressed by the nearby anterior inferior cerebellar artery (arrows), which had become redundant. C: The compressing artery was successfully transposed and the root exit zone (arrowheads) was decompressed.
nmc-56-77-g1.jpg
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F1
After 26 symptom-free years since the first MVD, HFS recurred ipsilaterally, and redo MVD showed that the PICA that had compressed the REZ of the facial nerve on initial MVD remained transposed (Fig. 1A), but the nearby AICA had become redundant and thus compressed the root exit zone (REZ) of the facial nerve (Fig. 1B). This artery was successfully displaced from the REZ of the nerve (Fig. 1C), resulting in complete cure of symptoms.
PMC4756247_02
A: At the first microvascular decompression for trigeminal neuralgia, the trigeminal nerve (CN V) was compressed by the anterior inferior cerebellar artery (arrow), which was successfully repositioned, resulting in cure of trigeminal neuralgia. B: Twenty years after the first microvascular decompression, hemifacial spasm developed on the same side of the face. At repeat microvascular decompression, the vertebral artery (VA), which had become more tortuous and redundant, started to displace the proximal part of the posterior inferior cerebellar artery (arrow) caudolaterally to impinge on the root exit zone of the facial nerve (CN VII). C: The vertebral artery was lifted by vascular tape (arrowheads) and fixed to the dura of the petrous bone, and the posterior inferior cerebellar artery (arrow) was repositioned by inserting prosthesis (asterisk) between the posterior inferior cerebellar artery and brainstem.
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PMC4756247_02_nmc-56-77-g2.jpg
F2
AICA that had previously compressed the TN remained transposed, but the nearby vertebral artery (VA), which had become tortuous and redundant, had started to displace the proximal part of the PICA to impinge on the REZ of the facial nerve (Fig. 2B). After transposing the VA by fixing it to the nearby petrous dura, the directly conflicting PICA that ran between the VA and the REZ was also displaced caudolaterally (Fig. 2C).