Prospects and Dilemmas of Endovascular Treatment for Vertebrobasilar Dolichoectasia

The use of flow-diverting stents has gained momentum as a curative approach in the treatment of complex proximal anterior circulation intracranial aneurysms. There have been some reported attempts of treating formidable lesions in the posterior circulation. Posterior circulation giant fusiform aneurysms have a particularly aggressive natural history. To date, no one approach has been shown to be comprehensively effective or low risk. The authors report the initial results, including the significant morbidity and mortality encountered, with flow diversion in the treatment of large or giant fusiform vertebrobasilar aneurysms at Millard Fillmore Gates Circle Hospital. The authors retrospectively reviewed their prospectively collected endovascular database to identify patients with intracranial aneurysms who underwent treatment with flow-diverting devices and determined that 7 patients had presented with symptomatic large or giant fusiform vertebrobasilar aneurysms. The outcomes of these patients, based on the modified Rankin Scale (mRS), were tabulated, as were the complications experienced. Among the 7 patients, Pipeline devices were placed in 6 patients and Silk devices in 1 patient. At the last follow-up evaluation, 4 patients had died (mRS score of 6), all of whom were treated with the Pipeline device. The other 3 patients had mRS scores of 5 (severe disability), 1, and 0. The deaths included posttreatment aneurysm ruptures in 2 patients and lack of improvement in neurological status related to presenting brainstem infarcts and subsequent withdrawal of care in the other 2 patients. Whether flow diversion will be an effective strategy for treatment of large or giant fusiform vertebrobasilar aneurysms remains to be seen. The authors' initial experience suggests substantial morbidity and mortality associated with the treatment and with the natural history. As outcomes data slowly become available for patients receiving these devices for fusiform posterior circulation aneurysms, practitioners should use these devices judiciously.

The long-term prognosis of patients with vertebrobasilar dolichoectasia (VBD) is unknown. The purpose of this study was to explore the natural history of VBD, evaluate its progression, and examine factors that may influence the clinical course of this condition. We conducted a prospective clinical and imaging follow-up study of 156 consecutive patients with VDB followed for an average of 11.7 years. Predictors of events were evaluated by multivariate analysis. Survival analysis was used to evaluate rates of incidence. During follow-up, 93 patients (60%) experienced at least one event: 75 patients had stroke (59 ischemic and 21 hemorrhagic), 31 patients had new compressive symptoms, and 2 patients had hydrocephalus. Events were significantly associated with the severity of VBD, i.e., diameter, height of bifurcation, and lateral displacement of the basilar artery. During follow-up VBD progressed in 43% of patients. Progression of VBD was associated with a higher morbidity and mortality. The cumulative proportion of survivors free of adverse health event was 54.1 at 5 years, 39.5 at 10 years, and 23.5 at 15 years. During follow-up, 62 patients died and stroke was the most common cause of death. The long-term prognosis of patients with vertebrobasilar dolichoectasia (VBD) depended mainly on the severity of the condition at diagnosis and on its evolutionary characteristics. Progression of VBD exposed patients to high risk of adverse events, especially stroke.

There are only limited epidemiological studies evaluating the association between vertebrobasilar dolichoectasia (VBD) and outcomes. This study was designed to elucidate the outcome and prognosis of adults diagnosed with VBD by magnetic resonance angiography (MRA) and to ascertain if these outcomes were independent of known vascular risk factors. A cohort study was designed to compare VBD cases identified retrospectively from a computerised database of MRA reports with age and sex matched controls evaluated after a 4-7 year period, and 1440 MRA reports were reviewed. The inclusion criteria were age > or =18 years and a radiological diagnosis of VBD. Patients were excluded if there was haemodynamically significant stenosis or occlusion of the posterior circulation. Data were obtained by medical record review and telephone questionnaires. The primary outcome measure was transient or fixed posterior circulation dysfunction (PCD), with a secondary outcome measure of all cause mortality. Sixty four VBD cases were obtained, and 19 cases (30%) were excluded due to refusal and/or insufficient follow up data. From the same computerised database, 45 controls were selected by consecutive sampling. The mean age at follow up was 73.4 years for VBD cases and 73.1 years for controls, with a median follow up period of 64 months. VBD was associated with fixed/transient PCD (p = 0.0001; estimated adjusted odds ratio (OR) of 20.6 and confidence interval (CI) of 4.4 to 95.3), and with all cause mortality (OR = 3.6 CI 1.3 to 10.3); (p = 0.018). VBD cases had 36% mortality, with 50% occurring within 34 months of the initial diagnosis. The VBD cumulative survival curve was statistically different from the controls (p = 0.012 by Mantel-Cox log rank test). This study suggests that VBD may be an independent risk factor for stroke. VBD cases had an increased likelihood for PCD, all cause mortality, and reduced cumulative survival independent of other vascular risk factors in this cohort. Larger population based prospective studies are required to verify these results.