Rammos, Stylianos K.

Abstract The progressive establishment of endovascular management in treating intracranial aneurysms had lead to continuous technique advancements and development of innovative technologies. Flow diverters are “stent-like” devices currently used for complex unruptured aneurysms allowing endoluminal reconstruction of the parent artery and occlusion of the aneurysm sac. In the present article, we review the development of flow diversion devices through in vitro and in vivo studies to clinical practice and summarize recent clinical data.

Recent clinical and experimental evidence has challenged the traditional concept of the venous system as a “passive” element in the genesis and evolution of intracranial vascular malformations. The authors review the clinical and experimental evidence linking the venous system and its anomalies to the genesis of various intracranial vascular malformations, including dural arteriovenous fistulas, cavernous malformations, parenchymal arteriovenous malformations, and capillary telangiectasia. They also describe the potential significance of different associations of these vascular anomalies.

Object The purpose of this study was to determine the incidence of shunt infection in patients with subarachnoid hemorrhage (SAH) after converting an external ventricular drain (EVD) to a ventriculoperitoneal (VP) shunt using the existing EVD site. The second purpose was to assess the risk of shunt malfunction after converting the EVD to a permanent shunt irrespective of the cerebrospinal fluid (CSF) protein and red blood cell (RBC) counts. Methods Data obtained in 80 consecutive adult patients (18 men and 62 women, mean age 60.8 years, range 33–85 years) who underwent direct conversion of an EVD to a VP shunt for post-SAH hydrocephalus between August 2002 and March 2007 were retrospectively reviewed. In each patient, the existing EVD site was used to pass the proximal shunt catheter. In no patient was VP shunt insertion delayed based on preoperative RBC or protein counts. Results The mean period of external ventricular drainage before VP shunt placement was 14.1 days (range 3–45 days). No patient suffered ventriculitis. The mean perioperative CSF protein level was 124 mg/dl (range 17–516 mg/dl). The mean and median perioperative RBC values in CSF were 14,203 RBCs/mm3 and 4600 RBCs/mm3 (range 119–290,000/mm3), respectively. No patient was lost to follow-up. The mean follow-up duration was 24 months (range 2–53 months). Three patients (3.8%) had shunt malfunction related to obstruction of the shunt system after 15 days, 2 months, and 18 months, respectively. There were no shunt-related infections. No patient suffered a clinically significant hemorrhage from ventricular catheter placement after VP shunt insertion. Conclusions In adult patients with aneurysmal SAH, conversion of an EVD to a VP shunt can be safely done using the same EVD site. In this defined patient population, protein and RBC counts in the CSF do not seem to affect shunt survival adversely. Thus, conversion of an EVD to VP shunt should not be delayed because of an elevated protein or RBC count.