Tomasello Francesco, Conti Alfredo, Angileri Filippo F, Cardali Salvatore
Department of Neurosurgery, University of Messina, Policlinico Universitario, Via Consolare Valeria 1, 98125, Messina, Italy.
Acta Neurochir (Wien). 2015 Apr;157(4):607-10. doi: 10.1007/s00701-015-2358-z. Epub 2015 Feb 6.
The "telo-velar" approach is an alternative to cerebellar splitting to gain access to the fourth ventricle through the so-called cerebello-medullary fissure (CMF).
In this approach, the CMF is exposed and access to the ventricle is obtained by incising the tela chorioidea and inferior medullary velum. This approach enables the exploration of the entire ventricle cavity from the obex to the aqueduct.
The exposure of the fourth ventricle is satisfactory and the floor of the fourth ventricle can be visualised early and protected. The extent of resection and outcome are satisfactory in most patients, including those with large tumours or lesions attached to the lateral or superolateral recesses of the ventricle. The deep rostral tumour attachment is the main limitation of the telo-velar approach.
• Early exposure of the interface lesion-floor of the fourth ventricle favours a safer tumour dissection. • We feel that resection of tonsils is not necessary in the surgical setting. • The posterior arch of C1 should be removed only if the tonsils are below the level of the foramen magnum. • The improved access to the lateral recess of the ventricle makes the telo-velar approach particularly effective in lesions attached to cerebellar peduncles. • The wide dissection of the cerebello-medullary fissure and gentle tonsils retraction may prevent from the occurrence of cerebellar mutism or other major cerebellar dysfunctions. • Even the bilateral opening of the CMF does not result in cerebellar mutism if wide and cautious dissection, avoiding retraction and vascular injuries, is obtained. • The exposure of the fourth ventricle was satisfactory also in patients harbouring lesions attached to the lateral or even the superolateral recesses of the ventricle. • A deep rostral tumour attachment seems to be, at least in our experience, the main specific limitation of the telo-velar approach. • The risk of hydrocephalus can be reduced by opening of the fissure bilaterally, exposing the aqueduct, and by cisterna magna-fourth ventricle communication augmentation. • The EVD is taken in place for 48-72 h to prevent possible abrupt increase of the intracranial pressure and to favour wound closure.
“终板-小脑幕”入路是一种替代小脑切开术的方法,通过所谓的小脑延髓裂(CMF)进入第四脑室。
在此入路中,暴露CMF,并通过切开脉络丛和下髓帆进入脑室。该入路能够从闩部至导水管对整个脑室腔进行探查。
第四脑室的暴露情况良好,第四脑室底部能够早期可视化并得到保护。在大多数患者中,包括那些患有大肿瘤或病变附着于脑室侧隐窝或上外侧隐窝的患者,切除范围和结果都令人满意。肿瘤向吻侧深部附着是终板-小脑幕入路的主要限制。
• 早期暴露第四脑室底部与病变的界面有利于更安全地进行肿瘤切除。• 我们认为在手术中没有必要切除扁桃体。• 只有当扁桃体低于枕骨大孔水平时才应切除C1后弓。• 改善对脑室侧隐窝的显露使终板-小脑幕入路在附着于小脑脚的病变中特别有效。• 广泛分离小脑延髓裂并轻柔牵拉扁桃体可防止小脑缄默症或其他严重小脑功能障碍的发生。• 如果能够进行广泛且谨慎的分离,避免牵拉和血管损伤,即使双侧打开CMF也不会导致小脑缄默症。• 对于病变附着于脑室侧隐窝甚至上外侧隐窝的患者,第四脑室的暴露情况也令人满意。• 至少根据我们的经验,肿瘤向吻侧深部附着似乎是终板-小脑幕入路的主要特定限制。• 通过双侧打开裂隙、暴露导水管以及增加枕大池与第四脑室的交通,可以降低脑积水的风险。• 放置脑室外引流48-72小时,以防止颅内压突然升高并促进伤口愈合。