Table 1.
Baseline characteristics of n = 52 patients recieving supratentorial cerebrospinal fluid diversion using image-guided trigonal ventriculostomy during retrosigmoid craniotomy for cerebellopontine angle tumors.
| Patient characteristics | Total (n = 52, 100%) |
|---|---|
| Sex | |
| Female [n (%)] | 31 [59.6] |
| Female/male ratio | 1.47 |
| Age | |
| Mean age in years [median (range)] | 53 [55 (11–79)] |
| Tumor characteristics | |
| Side | |
| Left [n (%)] | 24 (46%) |
| Right/left ratio | 1.17 |
| Preoperative tumor volume | |
| Mean volume in cm3 [median (range)]a | 22 [15; (4–88)] |
| Localization | |
| Cerebellopontine angle | 40 (77%) |
| Spheno-petroclival | 5 (10%) |
| Petrous apex | 4 (8%) |
| Tentorium | 2 (4%) |
| Foramen magnum | 1 (2%) |
| Histology | |
| Vestibular schwannoma | 29 (62%) |
| Meningioma | 14 (27%) |
| Trigeminal schwannoma | 3 (6%) |
| Lower cranial nerve schwannoma | 2 (4%) |
| Peripheral nerve sheet tumor | 1 (2%) |
| Cholesterol granuloma | 1 (2%) |
| Epidermoid | 1 (2%) |
| Primitive neuro-ectodermal tumor | 1 (2%) |
| Koos Grade in vestibular schwannoma (n = 29) | |
| I or II | 0 (0%) |
| III | 8 (28%) |
| IV | 21 (73%) |
| Volumetrics | |
| Mean posterior fossa volume cm3 [median (range)]b | 176 [179 (131–222)] |
| Mean tumor volume / posterior fossa volume ratio | 0.125 |
| Hydrocephalus | 14 (27%) |
| Affection of 4th Ventricle | |
| Open | 13 (25%) |
| Distorted but patent | 32 (61%) |
| Obstructed | 7 (14%) |
| Brainstem configuration | |
| Normal | 3 (6%) |
| Impression | 17 (33%) |
| Compression | 22 (42%) |
| Dislocation | 10 (19%) |
| Cerebellar Edema | |
| None | 41 (79%) |
| Unilateral | 9 (17%) |
| Bilateral | 2 (4%) |
| Tonsillar transforaminal herniation | 7 (14%) |
| Effacement of CSF cisterns surrounding the brainstem | 18 (35%) |
| Radiological signs of upward transtentorial herniation | |
| Upward transtentorial herniation | 1 (2%) |
| Flattening or reversal of the smile-shaped quadrigeminal cistern | 12 (23%) |
| Obliteration of the quadrigeminal and superior cerebellar cistern | 8 (15%) |
| “Spinning top” appearance of midbrainc | 1 (2%) |
CPA, cerebellopontine angle; CSF, cerebrospinal fluid.
a
The volume of the tumor was contoured on each slice of the available MR and CT scans.
b
The volume of the posterior fossa was contoured from the tentorial opening, along the tentorial border and the bony border of cerebellar hemispheres down to the foramen magnum.
c
Due to bilateral compression of the posterior aspect of the midbrain.