Telovelar versus Transvermian Approach in Management of Patients with Fourth Ventricular Tumors

Abstract

Background Approaching the fourth ventricle surgically is particularly challenging due to the limited working space provided by the important surrounding cerebrovascular structures. Its close relationship to the surrounding neural structures, including the brainstem and cerebellum, is the major limitation for surgical access. Various surgical routes to the fourth ventricular space will be described in the literature, including the conventional transvermian approach. Recent clinical and anatomical studies have suggested that the telovelar approach will maximize the extent of surgical exposure and working angle while minimizing operative morbidity. Objectives Our primary objective is to evaluate the efficacy and outcome of each approach in handling tumors within different parts of 4th ventricle. Our secondary objective is to analyze approach related complication and limitations of application to find best surgical option for those patients with posterior fossa lesions. Methods The following electronic databases will be searched from 2000 to 2019: PubMed, Google scholar, Cocharne database of systematic reviews, EMBASE and Science direct using Keywords ''Telovelar approach'', ''Transvermian approach'', ''fourth ventricular tumours'', ''Medullary velum''. Studies will be eligible if they contain the target Keywords in title or abstract, addressing our subject. Afterwards the full text of the article will be reviewed to exclude full texts not fulfilling the criteria or deviating from the initial impression taken from the title/abstract reviewing. References\ bibliography of the selected article will be sorted by discussion between study team (Student, Director and Codirectors). Results A total of 130 study were screened for eligibility, 6 studies were included in our systematic review for comparing the Telovelar and Transvermian approach in reaching posterior fossa lesions located within 4th ventricle regarding efficacy, clinical outcome and improvement, safety and complication. It was found that each approach has its own merits and demerits with nearly no difference between them regarding efficacy and safety, however slight superiority was linked to Telovelar approach in minimizing post-operative posterior fossa syndrome and Hydrocephalic changes. Conclusion we concluded that, 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, However the telovelar approach is generally preferred.