神经系统疾病

Telovelar Approach for Midline Posterior Fossa Tumors in Paediatrics: 25 Cases Experience

Abstract

Mohamed I Refaat, Ehab A Elrefaee and Walid E Elhalaby

Background: The classic transvermian route for excision of fourth ventricular tumors could be associated with postoperative cerebellar mutism. The Telovelar approach leads to the fourth ventricle via the cerebellomedullary fissure, avoiding retraction on the dentate nuclei and vermian incisions, hence lowering the incidence of cerebellar mutism. Objective: The aim of this study is to evaluate the Telovelar approach for excision of fourth ventricular tumors.

Patients and methods: This retrospective study was conducted on 25 cases with midline posterior fossa tumors collected between 2012 and 2014. All cases were operated upon via the telovelar approach succeeded by microscopic tumor excision. Follow up data were collected regarding the degree of excision (total, near total, and subtotal), and postoperative complications. Mean follow up period was 5 months.

Results: Age ranged from 2 to 8 years (mean 5.6 years). The most common was medulloblastoma (13 cases), followed by ependymoma (10 cases), and then choroid plexus papilloma (2 cases). Gross total excision was achieved in 8 cases (32%), near total excision (˃80% of tumor volume) in 14 cases (56%), and subtotal excision (˂80% of tumor volume) in 3 cases (12%). We experienced cerebellar mutism in 2 cases (8%) which improved in one case in the long term postoperative follow up. None of the cases had truncal ataxia. Two cases (8%) had postoperative facial palsy, while 3 cases (12%) had postoperative bulbar affection. There were two mortalities in this study, which were related to bulbar palsy and chest infection.

Conclusion: Telovelar approach to the fourth ventricle is becoming a widespread technique for removing midline posterior fossa tumors. It gives excellent access and visualization to the fourth ventricle, with a low incidence of postoperative cerebellar mutism.