Porus acousticus skin#
A longer incision placed more medially was used in patients with short thick necks, while a shorter skin incision placed more laterally was used in those with long thin necks. A curvilinear skin incision of 12 cm length was placed 3–4 cm posterior to the mastoid. Surgical procedureĪll operations were done by single neurosurgeon (IY), using the retrosigmoid suboccipital transmeatal approach in the lateral position. Patients with neurofibromatosis type 2 or with a recurrent tumour were excluded from the study. In this study we analysed the 50 patients with large tumours. The extrameatal diameter of the tumours was ⩾3 cm in 50 of the 89 tumours ( large 56%), and <3 cm in 39 ( small to medium 44%). The subjects consisted of 89 consecutive patients with unilateral acoustic neurinomas in the period from 1992 to 2001. Very favourable results can be obtained using the retrosigmoid approach for the removal of large acoustic neurinomas. All but two patients (96%) had a good functional outcome.Ĭonclusions: The method resulted in a high rate of functional facial nerve preservation, a low incidence of complications, and good functional outcomes, with no mortality and minimal morbidity. Cerebrospinal fluid leak occurred in 4%, but there were no cases of meningitis. One patient recovered useful hearing after tumour removal. The facial nerve was anatomically preserved in 92% of the patients and 84% had excellent facial nerve function (House-Brackmann grade 1/2).
The tumour was removed completely in 43 of 50 patients (86%). Results: There were no postoperative deaths. The last pieces of tumour were removed by sharp dissection from the facial nerve bidirectionally, and resected cautiously in a piecemeal fashion. Excision began with the large extrameatal portion of the tumour, followed by removal of the intrameatal tumour, and then removal of the residual tumour in the extrameatal region just outside the porus acusticus. Methods: Large acoustic neurinomas (mean (SD), 4.1 (0.6) cm) were removed from 50 consecutive patients by the retrosigmoid suboccipital approach while monitoring the facial nerve using a facial stimulator-monitor. We hypothesize that this location is related to the presence of a rich vascular plexus of the dura mater in this area.Objective: To evaluate the safety and efficacy of removing large acoustic neurinomas (⩾3 cm) by the retrosigmoid approach. These imaging criteria allows differentiation between hemangioma and neurinoma. Similar signal abnormalities were present in the adjacent temporal bone, and CT scan demonstrated a honeycomb appearance with intra-tumoral bony spicules.
They were hyperintense on T1-weighted images, strongly hyperintense on T2-weighted images with a characteristic progressive and marked enhancement after injection of gadolinium DTPA.
MRI showed a millimeter-sized tumor, located in the porus acusticus, developing perpendicular to the axis of the acoustico-facial nerves, surrounding them. We present two cases of hemangiomas located at the porus acusticus, an even more rare site. Hemangiomas near the geniculate ganglion or in the internal acoustic meatus are well known but rare. Impact of imaging studies: case reports Hemangioma of the porus acusticus.