Telovelar approach versus transvermian approach in management of fourth ventricular tumors

Abstract

BackgroundThe relationships of the fourth ventricle to the cerebellar surfaces and the fissures through which the fourth ventricle is approached surgically are among the most complex in the brain. The area in and around the fourth ventricle may be affected by a variety of neoplasms. Some are unique to the fourth ventricle; others are also found in different locations. The two most common surgical approaches to the fourth ventricle are the transvermian and the telovelar approaches.The aim of this studyThe aim of this study is to compare the results of telovelar and transvermian approaches in the management of fourth ventricular tumors with regard to clinical outcome and extent of tumor excision.Patients and methodsThis study includes 40 patients presented at Ain Shams University Hospital and Nasser Institute with the diagnosis of fourth ventriclular tumors in a 4-year period between 2011 and 2015. Surgical treatment was done in all cases in form of (1) a CSF diversion for hydrocephalic patients through insertion of V-P shunt or EVD. (2) Completely randomly choosing an approach, 20 patients were operated through the transvermian approach (50% of all patients) and 20 patients were operated through the telovelar approach. Patients were examined clinically, radiologically, and functionally using the Karnofsky performance scale at the postoperative period, every 3 months for the first year, and then 6 months thereafter.ResultsTotal excision of the tumor was achieved in 27 patients (67.5% of all patients) and 15 patients (75% of 20 patients operated via telovelar approach).There were 13 patients (32.5%) with different postoperative complications, 6 patients underwent telovelar approach,1 case of superficial infection, 3 cases of bulbar palsy (15% of patients operated via telovelar approach), and 3 cases of cerebellar mutism (15% of patients operated via transvermian approach and 7.5% of all patients).ConclusionThe telovelar approach can give better exposure to the fourth ventricle in craniocaudal direction and lateral direction without splitting of the vermis. For lesions in the upper half, the ventricletelovelar approach can be used but we have to shift to the transvermian approach for complete resection. The transvermian approach has a higher risk of postoperative cerebellar mutism syndrome particularly in children.