Endoscopic Treatment Strategy for a Disproportionately Large Communicating Fourth Ventricle: Case Series and Literature Review

Abstract

An isolated fourth ventricle (IFV) is characterized by fourth ventricular dilation due to obstruction of its inlet and outlet. A disproportionately large communicating fourth ventricle (DLCFV) is a rare subtype of IFV, characterized by dilation of the fourth ventricle, regardless of the size of the lateral ventricles, with no apparent obstruction of the cerebral aqueduct. To our knowledge, this is the first case series describing endoscopic diagnosis and treatment strategy for DLCFV. We retrospectively reviewed six cases of DLCFV in which endoscopic surgery was performed at our institution and affiliated facilities between June 2013 and March 2017. DLCFV was diagnosed using radiographic imaging and intraoperative endoscopy. We also conducted a PubMed search and included only original studies related to DLCFV treatment written in English in our review of the literature. Endoscopic third ventriculostomy (ETV) was performed in all patients. Additional endoscope-assisted placement of a fourth ventriculoperitoneal (VP) shunt was performed in two patients who could not be managed with ETV alone because of severe adhesion of the interpeduncular cistern due to subarachnoid hemorrhage (SAH). The patients’ symptoms and the size of the fourth ventricle improved with surgical treatment, without complications. Endoscopic surgery for DLCFV appears to be a safe and effective treatment. Based on our treatment strategy, ETV is the first-line treatment for DLCFV. Endoscope-assisted placement of the fourth VP shunt can be treatment for severe adhesion of the interpeduncular cistern.

Endoscopic placement of a triventricular stent for complex hydrocephalus and isolated fourth ventricle: illustrative case

“… 10 , 24 , 26 , 31 Regardless of the treatment modality used, complications and failures are a constant problem. 12 , 20 , 21 , 24 , 26 , 31 , 32 Microsurgical fenestration aims to directly reopen the fourth ventricle. 11 , 13 , 30 , 33 In conjunction, an additional catheter is commonly connected to a preexisting shunt system or a separate drainage device.…”

“…14,[18][19][20] As in our case, fourth ventricular trapping can also occur as a result of scarring following posterior fossa tumor surgery. 1,4,10,[18][19][20][21][22][23] The rate of postresection hydrocephalus for tumors in the posterior fossa ranges from 10% to 40% in children. 4,[23][24][25] It is likely that tumor location and subtype have some degree of influence on the development of hydrocephalus.…”

Endoscopic Third Ventriculostomy for an Idiopathic Disproportionately Large Communicating Fourth Ventricle: A Case Report

“…DLCFV is a rare disease characterized by dilatation of the fourth ventricle regardless of lateral ventricle size without definite obstruction of the cerebral aqueduct, indicating patency of the inlet of the fourth ventricle [3]. Its treatment has not been thoroughly established owing to the characteristic hemodynamics of the CSF and a poor understanding of its etiology and pathophysiology [2,4].…”

“…Its treatment has not been thoroughly established owing to the characteristic hemodynamics of the CSF and a poor understanding of its etiology and pathophysiology [2,4]. Treatment for obstructive hydrocephalus includes ventricular drainage, ventriculoperitoneal shunting Kawabata et al [3] proposed the diagnosis of DLCFV using radiologic imaging of a dilated fourth ventricle and intraoperative endoscopic findings of a patent aqueduct of Sylvius and suggested ETV as a first-line treatment. In our case, based on this information, we conducted ETV after intraoperatively confirming the patency of the aqueduct of Sylvius.…”

“…DLCFV is often confused with an isolated fourth ventri-Endoscopic Third Ventriculostomy for an Idiopathic Disproportionately Large Communicating Fourth Ventricle: A Case Report cle (IFV), also known as a trapped or encysted fourth ventricle. IFV is defined as a markedly dilated fourth ventricle due to obstruction of the aqueduct of Sylvius and foramina of Magendie and Luschka [2], whereas DLCFV features a dilated fourth ventricle but a patent aqueduct of Sylvius with no definite obstruction [3].…”