John Millar

Endovascular treatment of cranial dural arteriovenous fistulae: a single-centre, 14-year experience and the impact of Onyx on local practise

IntroductionDural arteriovenous fistulae (DAVFs) are a potentially dangerous group of intracranial arteriovenous shunts with significant morbidity and mortality. Treatment has traditionally included transvenous and/or transarterial embolisation, which may be followed by surgical ligation. This study assesses the impact of Onyx on treatment.MethodsForty-nine consecutive patients referred for endovascular management of DAVFs between 1994 and 2008 were included in a retrospective, intention-to-treat analysis. DAVFs managed conservatively or purely surgically were excluded. Success rates and complications were compared between patients treated by transvenous, transarterial Onyx and transarterial non-Onyx material embolisation.ResultsFifty-six separate DAVFs were detected in 49 patients. Embolisation of 52 DAVFs was performed or attempted. Transvenous sinus occlusion of ten type I or II DAVFs resulted in cure but was unsuccessful in a single type IV fistula and three of the four indirect carotico-cavernous fistulae treated in this way. Two type I and nine type III/IV were identified in the transarterial, non-Onyx group and three of 11 (27.3%) were cured. Amongst the six type II and 20 type III/IV DAVFs belonging to the transarterial Onyx group, cure was achieved in 17 of 26 (65.4%) rising to 72.7%, considering only those cases where the fistula could be accessed and Onyx was injected.ConclusionsThe introduction of Onyx has improved the endovascular cure rate of DAVFs, particularly types III and IV. Advances in technology have made an endovascular approach the management of choice for the majority of DAVFs requiring treatment. Low complication rates are achievable.

The Natural History of Cranial Dural Arteriovenous Fistulae With Cortical Venous Reflux-The Significance of Venous Ectasia

BACKGROUND: The quoted risk of hemorrhage from dural arteriovenous fistulae with cortical venous reflux varies widely, and the influence of angiographic grade on clinical course has not previously been reported. OBJECTIVE: To assess the risk of hemorrhage and the influence of angiographic grade on this risk, compared with known predictors of hemorrhage such as presentation. METHODS: Seventy-five fistulae with cortical venous reflux identified in our arteriovenous malformations clinic between 1992 and 2007 were followed up clinically, and their angiograms were reviewed. RESULTS: There were 8 hemorrhages in 90 years of follow-up. The annual incidence of hemorrhage before any treatment was 13%, and 4.7% after partial treatment, giving an overall incidence of 8.9% before definitive treatment. Borden and Cognard grades were poor discriminators of risk for lesions with the exception of Cognard type IV lesions. These lesions, characterized by venous ectasia, had a 7-fold increase in the incidence of hemorrhage (3.5% no ectasia vs 27% with ectasia). Patients presenting with hemorrhage (20%) or nonhemorrhagic neurological deficit (22%) had a higher incidence of hemorrhage than those with a benign presentation (4.3%), but this may be directly linked to the presence of venous ectasia. CONCLUSION: In this series untreated dural arteriovenous fistulae with cortical venous reflux had a 13% annual incidence of hemorrhage after diagnosis. There was a significant difference between those with and without venous ectasia. This should be confirmed by further studies, but probably defines a high-risk subgroup of patients that requires rapid intervention.

Final results of the US humanitarian device exemption study of the low-profile visualized intraluminal support (LVIS) device

Introduction The low-profile visualized intraluminal support (LVIS) device is a new, braided, intracranial microstent designed for stent-assisted coiling. Objective To present the results of a single-arm, prospective, multicenter trial of the LVIS for treatment of wide-necked intracranial aneurysms. Methods 31 patients with unruptured, wide-necked (neck ≥4 mm or dome:neck ratio ≤2) intracranial aneurysms were treated with the LVIS device and bare platinum coils at six US centers (investigational device exemption G110014). Clinical follow-up was conducted at 30 days and 6 months. Angiographic follow-up was performed at 6 months. The primary safety endpoint was any major stroke or death within 30 days or major ipsilateral stroke or neurological death within 6 months. ‘Probable benefit’ was defined as ≥90% angiographic occlusion at 6 months. An independent core laboratory adjudicated the angiographic results. An independent clinical events committee adjudicated the clinical endpoints. Results Average aneurysm size was 7.2 mm (SD 3.8) and average neck width was 4.6 mm (SD 1.8). 68% of patients had a dome:neck ratio ≤2. LVIS placement was technically successful in 29/31 patients (93.5%). No primary safety endpoints occurred during the study (0%). No patient had a higher modified Rankin Score at 6 months than at baseline. 26/28 (92.9%) treated aneurysms with 6-month angiographic follow-up demonstrated ≥90% angiographic occlusion. 21/28 (75%) were completely occluded at follow-up. Conclusions The LVIS device facilitated the coil embolization of wide-necked intracranial aneurysms with high rates of technical success, an excellent safety profile, and very high rates of complete and near-complete occlusion at follow-up. Trial registration number NCT01541254.

Mammillary Body Damage Results in Memory Impairment But Not Amnesia

Abstract Isolated mammillary body pathology is rare, and there remains controversy as to whether such focal lesions will result in amnesia. We report two cases of lesions to the mammillary bodies arising from a suprasellar tumour. Neither case underwent radical surgical or radiotherapy treatment, which in themselves might have affected memory functioning. In both patients, extensive memory testing across a wide range of memory tasks showed relatively limited anterograde memory impairment which was mainly evident on some but not all delayed recall tasks. Neither patient showed evidence of significant retrograde amnesia. Our negative findings contrast with recent case reports, and these conflicting observations are discussed in terms of the possible role of coexistent cerebral pathology that may exacerbate the effects of mammillary body lesions to produce amnesic levels of performance. Our data point to a limited/selective role for the mammillary bodies in human memory, and raise the possibility that recove...

Spontaneous dissection of the anterior inferior cerebellar artery

Abstract A patient presented with the clinical features of a brain stem infarct. MRI confirmed changes of infarction but also revealed an unusual lesion in the left cerebellopontine angle cistern. The evolution of this lesion on MRI, together with angiographic changes, indicated a dissecting aneurysm of the left anterior inferior cerebellar artery, a previously unreported phenomenon. The presentation, causes and diagnosis of intracranial dissection are discussed.

The UKNG database: a simple audit tool for interventional neuroradiology

IntroductionThe UK Neurointerventional Group (UKNG) has developed a unified database for the purposes of recording, analysis and clinical audit of neuroangiography and neurointerventional procedures. It has been in use since January 2002.MethodsThe database utilizes an Access platform (Microsoft) comprising separate but linked programs for data collection and analysis. The program that analyses aneurysm therapy has been designed to mirror the criteria used in the International Subarachnoid Aneurysm Trial (ISAT).ResultsData entered into the main database immediately update the analysis program producing clinical outcome scores in the form of a report. Our local database (Wessex) now contains records on more than 1,750 patients including nearly 350 aneurysm coilings and a total of approximately 500 neurointerventional, vascular procedures. Every time a new piece of information is added to the main database the reporting database is automatically updated which allows ‘real-time’ audit and analysis of one’s clinical practice. The clinical outcome scores for aneurysm treatment are presented in such a way that we can directly compare our results with the ‘Clinical Standard’ set by ISAT.ConclusionThis database provides a unique opportunity to monitor and review practice at national level. The UKNG wishes to share this database with the wider neurointerventional community and a copy of the software can be obtained free of charge from the authors.

Use of Hydrocoil in Small Aneurysms: Procedural Safety, Treatment Efficacy and Factors Predicting Complete Occlusion:

Coil technology has been directed to reduce recurrence rates and we have seen the introduction of trials comparing the efficacy of surface modified versus bare platinum coils (BPC). This article reports on one treatment strategy in the treatment of small aneurysms by the placement of Hydrocoil across the neck of the aneurysm. Procedural safety, treatment efficacy and factors which predict complete occlusion are evaluated. We retrospectively identified a subgroup of small aneurysms treated over a four-year period. Analysis comparing aneurysms treated with Hydrocoil and BPC versus Hydrocoil alone was undertaken. Eighty-five aneurysms were coiled; 62% with Hydrocoil alone, 38% in combination with BPC. At six-month follow-up, overall 50% were completely occluded, 39.5% had a neck remnant and 10.5% had a residual aneurysm. Complete occlusion was identified in 39% in the Hydrocoil and BPC group compared to 56% in the Hydrocoil alone group. In 56/76 (74%) cases analysed, Hydrocoil loop successfully bridged the neck of the aneurysm in which 38/76 (68%) of these were completely occluded at six-month follow-up. Thirteen procedure-related complications occurred. Aneurysms treated with Hydrocoil alone resulted in fewer recurrences compared with a combination of Hydrocoil and BPC. These data suggest that the technique of positioning Hydrocoil at the neck of the aneurysm increases the probability of complete occlusion and is therefore a strong predictor of aneurysm occlusion. In our experience, this technique did not demonstrate an increased risk of intra-procedural rupture or thrombo-embolic complications compared to conventional embolization with BPC.