To identify the predictors of symptomatic post-radiation T2 signal change in patients with arteriovenous malformations (AVM) treated with radiosurgery.

The charts of 211 consecutive patients with arteriovenous malformations treated with either gamma knife radisurgery or linear accelerator radiosurgery between 2000-2009 were retrospectively reviewed. 168 patients had a minimum of 12 months of clinical and radiologic follow-up following the procedure and complete dosage data. Pretreatment characteristics and dosimetric variables were analyzed to identify predictors of adverse radiation effects.

141 patients had no clinical symptomatic complications. 21 patients had global or focal neurological deficits attributed to symptomatic edema. Variables associated with development of symptomatic edema included a non-hemorrhagic symptomatic presentation compared to presentation with hemorrhage, p=0.001; OR (95%CI) = 6.26 (1.99, 19.69); the presence of venous rerouting compared to the lack of venous rerouting, p=0.031; OR (95% CI) = 3.25 (1.20, 8.80); radiosurgery with GKS compared to linear accelerator radiosurgery p = 0.012; OR (95% CI) = 4.58 (1.28, 16.32); and the presence of more than one draining vein compared to a single draining vein p = 0.032; OR (95% CI) = 2.82 (1.06, 7.50).

We postulated that the higher maximal doses used with gamma knife radiosurgery may be responsible for the greater number of adverse radiation effects with this modality compared to linear accelerator radiosurgery. We found that AVMs with greater venous complexity and therefore instability resulted in more adverse treatment outcomes, suggesting that AVM angioarchitecture should be considered when making treatment decisions.

To describe the results, technical feasibility, efficacy and challenges encountered in our preliminary experience using a self-expandable microstent, optimized for intracranial use, as an adjunct in the endovascular treatment of wide-necked aneurysms.

Only broad-necked aneurysms (dome-to-neck ratio £2, or an isolated neck size > 4.5 mm) were treated with Neuroform microstent from July 2003 to May 2004. The techniques used for stent deployment were either parallel or sequential. Angiographic results were recorded immediately for all patients and classified as Class 1 (complete occlusion), Class 2 (neck remnant) or Class 3 (sac remnant) by three interventional neuroradiologists not involved in the procedure. Follow-up angiography at six months was obtained for one case. Modified Rankin Score scale was assessed for all patients.

Seventeen intracranial aneurysms in a total of 18 patients were treated (mean age, 52.2 yr). Eight patients (44.4%) presented with acute subarachnoid hemorrhage. Eleven aneurysms (61.1%) were in the posterior circulation. Average dome size was 10.2 mm (range, 3.7-19.8 mm) and average neck size was 5.36 mm (range, 3.0-10.0 mm). Six out of seven aneurysms of the anterior circulation were approached with parallel technique. Eight aneurysms of the posterior circulation were approached with sequential technique. Average number of coils deployed was 9.64 (range, 4-23 coils). Eleven aneurysms (64.8%) resulted in Class 1 and/or Class 2. One technical failure was observed. Technical complications were recognized in four patients (23.5%), all of them with unruptured aneurysms in the anterior circulation. Two patients (11.7%) presented transient immediate clinical complications. One patient (5.8%) had minor permanent neurological complication. Neither major clinical complications nor death were encountered. Favorable clinical outcome (Modified Rankin Scale score 0-2) was observed in 88.2% of the patients (average follow-up time, 4.72 months).

Absence of major permanent complications and satisfactory immediate obliteration degree in our preliminary experience indicates that microstent-assisted coiling technique is useful for the minimally invasive treatment of broad-necked complex aneurysms that are not ideal for conventional endovascular treatment and are at a high risk for conventional surgical treatment.

Superior cerebellar artery aneurysms are rare. We present a clinical series of twelve of these aneurysms that were treated exclusively with endovascular coils.

A retrospective analysis of a prospectively collected database of cerebral aneurysms treated with coil embolization was performed. Clinical notes and radiological images were reviewed.

Twelve superior cerebellar artery aneurysms were treated in eleven patients between 1992 and 2001. Seven patients presented with subarachnoid hemorrhage, two with neurologic deficit, and two had asymptomatic aneurysms. Coiling resulted in complete aneurysm obliteration in six patients and incomplete obliteration in the other six. No subsequent hemorrhage occurred with follow-up between 6 and 119 months (mean follow-up 50 months). Procedural morbidity was one superior cerebellar artery infarct with good recovery. Management morbidity was one middle cerebral artery embolus during a follow-up angiogram that required thrombolysis with a good clinical result. Nine out of 11 patients on follow-up were performing at Glasgow Outcome Scale (GOS) 5. One patient with GOS 3 presented with a poor grade subarachnoid hemorrhage and the other patient with GOS 4 presented with a parenchymal hemorrhage due to an arteriovenous malformation.

Endovascular treatment of superior cerebellar artery aneurysms is an effective treatment strategy with low morbidity.