Neurosurgery Service, Virgen del Rocío University Hospital, Av. Manuel Siurot, S/N, 41013, Seville, Spain.
Group of Applied Neuroscience, Biomedicine Institute of Seville, Seville, Spain.
Childs Nerv Syst. 2021 Mar;37(3):885-894. doi: 10.1007/s00381-020-04939-2. Epub 2020 Oct 25.
An isolated fourth ventricle (IFV) is a rare entity observed in shunted patients and its treatment is still uncertain. Endoscopic aqueductoplasty has shown good results for restoring CSF flux between the third and fourth ventricles. However, it needs some grade of ventricular dilation to be performed. Some patients affected by IFV show slit-ventricle morphology in CT/MRI. Usually, the rise of opening pressure or the shunt externalization gets enough ventricular dilation. However, the lack of intracranial compliance in some patients makes these options unsuitable and high-ICP symptoms are developed without ventricular dilation.
We present a two cases series affected by IFV with no ventricular dilation in radiological exams. ICP sensors were implanted, observing high-ICP and establishing the diagnosis of craniocerebral disproportion. A two-stage surgical plan based on a dynamic cranial expansion followed by a supratentorial endoscopic aqueductoplasty was performed. A physical and mathematical model explaining our approach was also provided.
Chess-table cranial expansion technique was performed in both patients. Six/seven days after the first surgery, respectively, ventricular dilation was observed in CT. Endoscopic precoronal aqueductoplasty was then performed. No postoperative complications were described. IFV symptoms improved in both patients. Eighteen and 12 months after the two-stage surgical plan, the patients remain symptom-free and void of flow is still observed between the third and the fourth ventricles in MRI.
The two-stage approach was a suitable option for the treatment of these complex patients affected by both craniocerebral disproportion and isolated fourth ventricle.
孤立性第四脑室（IFV）是分流患者中观察到的一种罕见实体，其治疗仍不确定。内镜导水管成形术已显示出在恢复第三和第四脑室之间 CSF 流动方面的良好效果。然而，它需要一定程度的脑室扩张才能进行。一些受 IFV 影响的患者在 CT/MRI 上显示出狭缝脑室形态。通常，升高的颅内压或分流管外移会使脑室充分扩张。然而，一些患者颅内顺应性不足，使这些选择不合适，并且在没有脑室扩张的情况下出现高颅内压症状。
我们报告了两例影像学检查无脑室扩张的 IFV 病例。植入了颅内压传感器，观察到高颅内压并确立了颅腔与脑组织比例失调的诊断。采用基于动态颅骨扩张的两阶段手术计划，随后进行额顶内镜导水管成形术。还提供了解释我们方法的物理和数学模型。
两名患者均进行了棋盘式颅骨扩张技术。第一次手术后的第六/七天，分别在 CT 上观察到脑室扩张。然后进行内镜前冠状导水管成形术。没有术后并发症的描述。两名患者的 IFV 症状均得到改善。在两阶段手术计划后的 18 个月和 12 个月，患者仍然无症状，并且 MRI 仍然观察到第三和第四脑室之间的分流。
对于同时患有颅腔与脑组织比例失调和孤立性第四脑室的复杂患者，两阶段方法是一种合适的选择。
