Retractless Transvermian versus Telovelar Approach for Excision of Pediatric Fourth Ventricular Tumors: Surgical Technique, Clinical Outcome and Cerebellar Mutism

Background: Tumors of the fourth ventricle are always challenging due to the difficulty of its access as well as the complexity of eloquent nearby neural structures. Objective: To compare transvermian and telovelar approaches regarding the safety of the technique, the feasibility of total tumor resection, clinical outcome and relation to postoperative cerebellar mutism. Patients and Methods: A prospective study including forty pediatric patients having fourth ventricular tumors, patients were classified equally into two groups; Group I: 20 patients operated upon by retractless transvermian approach, Group II: 20 patients operated upon via telovelar approach. All patients were hydrocephalic and were subjected to ventriculoperitoneal shunt placement except eight cases did endoscopic third ventriculostomy (five and three cases of groups I and II respectively) 2-5 days prior to the definitiveposterior fossa surgery. Patients were followed clinically and radiologically on 3 months intervals postoperatively, for a mean period of 12 months. Results: In groups I and II respectively; gross total tumor excision was achieved in eighteen (90%) and seventeen patients (85%). Excellent and good clinical outcome immediately postoperative were noted in fourteen (70%) and thirteen patients (65%), and increased to 90% of each group at twelve months interval. Complication rates were 25% and 30% (five and six cases), postoperative cerebellar mutism was encountered in three (15%) and four patients (20%), mutism recovered in all cases within 2-6 weeks. Tumor recurrence recorded in three (15%) and one patient (5%). A single mortality case in this series (of group II – 5%) didn’t survive the sequelae of postoperative haematoma. Conclusion: Both transvermian (without sustained retraction) and telovelar approaches have no significant difference in safety, feasibility of total tumor excision, clinical outcome, postoperative complications and cerebellar mutism. The choice of either approach depends mainly on the surgeon s skills and preference. Telovelar approach is generally preferred. However, retractless tranvermian route is recommended for large tumors extending to the rostral fourth ventricle. © 2015 Egyptian Journal of Neurosurgery. Published by MEDC. All rights reserved