====== Telovelar approach ====== {{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/1HqK_1-QcK25XI3ADX-deg8DygqnjQjXG9PFTrLVdEnfKT7Y4y/?limit=15&utm_campaign=pubmed-2&fc=20240903042656}} ---- ---- The [[telovelar approach]] is an alternative to cerebellar splitting to gain access to the [[fourth ventricle]] through the so-called [[cerebellomedullary fissure]] (CMF). In the [[telovelar approach]], the [[cerebellomedullary fissure]] (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]]. see [[cerebellomedullary fissure approach]] The [[telovelar approach]], which lacks incision of any part of the cerebellum, provides an additional exposure to the [[lateral recess]]es and the [[foramen of Luschka]] ((Tanriover N, Ulm AJ, Rhoton AL Jr, Yasuda A. Comparison of the transvermian and telovelar approaches to the fourth ventricle. J Neurosurg. 2004 Sep;101(3):484-98. PubMed PMID: 15352607. )). It is a safer procedure for interventions involving the pathological lesions of the [[fourth ventricle]] floor ((Akakin A, Peris-Celda M, Kilic T, Seker A, Gutierrez-Martin A, Rhoton A Jr. The Dentate Nucleus and its Projection System in the Human Cerebellum: A Microsurgical Anatomical Study Dentate Nucleus Microsurgical Anatomical Study. Neurosurgery. 2014 Jan 19. [Epub ahead of print] PubMed PMID: 24448179.)). The unilateral approach is sufficient in most cases of small lesions. However, large fourth ventricle tumors are more problematic since they distort the normal anatomy with both [[vermis]] and [[cerebellar peduncle]]s thinned and stretched out. This puts the patient at increased risk for a neurological deficit, which is minimized with a bilateral telovelar approach. By illustrating the adequacy of this technique, Liu et al., emphasize the suitability of a rather unusual bilateral approach, which will provide excellent panoramic visualization of entire fourth ventricle and thus avoids complications usually associated with resections of large [[fourth ventricle tumor]]s ((Liu R, Kasper EM. Bilateral telovelar approach: A safe route revisited for resections of various large fourth ventricle tumors. Surg Neurol Int. 2014 Jan 30;5:16. doi: 10.4103/2152-7806.126081. eCollection 2014. PubMed PMID: 24678432.)). ====Key Points==== Early exposure of the interface lesion-[[floor of the fourth ventricle]] favours a safer tumour dissection. 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]]. A telovelar approach without the removal of the posterior [[arch]] of C1 allows for an optimal exposure of the fourth ventricle provided that critical nuances in patient positioning are considered ((Cho A, Lippolis MA, Herta J, Dogan M, Hedrich C, Azizi AA, Peyrl A, Gojo J, Czech T, Dorfer C. The telovelar approach for fourth ventricular tumors in children: is removal of the posterior arch of C1 necessary? Childs Nerv Syst. 2024 Sep;40(9):2707-2711. doi: 10.1007/s00381-024-06443-3. Epub 2024 May 4. PMID: 38703239; PMCID: PMC11322403.)) ---- The improved access to the [[lateral recess]] of the ventricle makes the telo-velar approach particularly effective in lesions attached to [[cerebellar peduncle]]s. The wide dissection of the [[cerebellomedullary 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, 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 ((Tomasello F, Conti A, Angileri FF, Cardali S. Telo-velar approach to fourth-ventricle tumours: how I do it. Acta Neurochir (Wien). 2015 Apr;157(4):607-10. doi: 10.1007/s00701-015-2358-z. Epub 2015 Feb 6. PubMed PMID: 25652723. )).