METHOD FOR DETERMINING RESECTION LIMITS OF POSTERIOR WALL OF INTERNAL AUDITORY CANAL IN VESTIBULOCOCHLEAR NERVE SURGERY Russian patent published in 2019 - IPC A61B6/03 A61B17/00 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to neurosurgery, and can be used to determine the limits of resection of the posterior wall of the internal auditory canal (IAC) when removing acoustic neurinoma from retro-gum access. Trajectory of safe resection of the internal auditory canal is determined using high-resolution CT scans and bony landmarks. On the CT of the patient in the frontal projection in the bone window, measuring the distance from the middle point of the back edge of the internal auditory canal to the labyrinth boundaries, adding distance of 1 mm. CT in the axial projection at the level of the middle ear canal is used to measure the distance from its posterior edge on the back wall of the internal auditory canal, marking the A1 point, and on the posterior pyramid of the temporal bone, marking the point A, connecting which define the drilling axis. Location of entry point of drilling axis on rear side of pyramid of temporal bone is fixed from lateral border of trepanation window, which is located on line between ASTERION points and posterior base of mastoid process. Point of exit of drilling axis on surface of occipital bone is determined in coordinate system relative to median line in sagittal plane and line drawn from ASTERION point in axial plane. Medial border of the trephine opening is determined from the point of exit of the drilling axis by adding the radius of the working portion of the boron.

EFFECT: method provides higher accuracy and reduced traumatism when determining the boundaries of resection of the posterior wall of the internal auditory canal, increases the radicality of intramidal tumour removal and reduces the probability of damaging the labyrinth structures, easier orientation of the surgeon in the location of brain structures within the range of access due to preoperative planning of the resection limits and the possibility of intraoperative control of the IAC rear wall resection process.

1 cl, 3 dwg, 1 ex