Hans Nahser

Hydrogel-coated coils versus bare platinum coils for the endovascular treatment of intracranial aneurysms (HELPS): a randomised controlled trial

BACKGROUND Coated coils for endovascular treatment of cerebral aneurysm were developed to reduce recurrence and retreatment rates, and have been in clinical use for 8-9 years without robust evidence to determine their efficacy. We assessed the efficacy and safety of hydrogel-coated coils. METHODS This randomised trial was undertaken in 24 centres in seven countries. Patients aged 18-75 years with a previously untreated ruptured or unruptured cerebral aneurysm of 2-25 mm in maximum diameter were randomly allocated (1:1) to aneurysm coiling with either hydrogel-coated coils or standard bare platinum coils (control). Randomisation was done with a computer-generated sequence, stratified by aneurysm size, shape, and dome-to-neck ratio; intention to use assist device; and by region. Participants and those assessing outcomes were masked to allocation. Analysis was by modified intention to treat (excluding missing data). Primary outcome was a composite of angiographic and clinical outcomes at 18-month follow-up. We also did prespecified subgroup analyses of characteristics likely to be relevant to angiographic outcome. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN30531382. FINDINGS 249 patients were allocated to the hydrogel coil group and 250 to the control group. In 44 of 467 patients for whom an 18-month composite primary outcome was unavailable, 6-month angiographic results were used. 70 (28%) patients in the hydrogel group and 90 (36%) control patients had an adverse composite primary outcome, giving an absolute reduction in the proportion of adverse composite primary outcomes with hydrogel of 7·0% (95% CI -1·6 to 15·5), odds ratio (OR) 0·73 (0·49-1·1, p=0·13). In a prespecified subgroup analysis in recently ruptured aneurysms, there were more adverse composite primary outcomes in the control group than in the hydrogel group-OR 2·08 (1·24-3·46, p=0·014). There were 8·6% fewer major angiographic recurrences in patients allocated to hydrogel coils-OR 0·7 (0·4-1·0, p=0·049). There were five cases of unexplained hydrocephalus in not-recently-ruptured aneurysms in the hydrogel coil group and one case in the control group. INTERPRETATION Whether use of hydrogel coils reduces late aneurysm rupture or improves long-term clinical outcome is not clear, but our results indicate that their use lowers major recurrence. FUNDING MicroVention Inc.

Cerebral aneurysm associated with an intracranial tumour: staged endovascular and surgical treatment in two cases.

Two cases are reported in which an anterior communicating artery aneurysm was associated with an intracranial tumour. The tumour was a suprasellar meningioma in one case and an optic chiasm/hypothalamic astrocytoma in the other. In both cases, the aneurysm was successfully embolized using Guglielmi detachable coils. Subsequently craniotomy was performed with complete excision of the meningioma and subtotal removal of the astrocytoma. Endovascular techniques can be employed to make the surgical excision of an intracranial tumour co-existing with an incidental aneurysm safer.

Surgical Disconnection of the Cortical Venous Reflux for High-Grade Intracranial Dural Arteriovenous Fistulas

OBJECTIVES To assess the clinical outcome, complications, and angiographic outcomes after surgical disconnection of intracranial dural arteriovenous fistulas (DAVFs). METHODS Analysis of prospectively collected data, including clinical presentation, preoperative angiographic findings, postoperative complications, clinical, and angiographic outcomes. RESULTS Between January 2002 and January 2012, 25 patients underwent surgery for DAVFs. The anatomical locations included tentorial (8), ethmoidal (8), foramen magnum (5), middle fossa (2), torcular (1), and parafalcine (1). All had cortical venous reflux (CVR) and all were treated with craniotomy and disconnection of CVR. Two patients required repeat surgery for residual CVR. One patient had a postoperative seizure. There were no other complications. All patients had complete disconnection of CVR confirmed by digital subtraction angiography. None of the patients have had hemorrhage or recurrence of CVR on follow-up. CONCLUSIONS Surgical disconnection of CVR for high-grade intracranial DAVFs is highly effective and can be performed with very low complication rates. Where embolization cannot be performed safely, surgical disconnection (rather than stereotactic radiosurgery) is the treatment of choice for high grade DAVFs.

Initial experience of coiling cerebral aneurysms using the new Comaneci device

We present our initial patient experience with an innovative temporary bridging device, the Comaneci (Rapid Medical, Israel), to assist in the coiling of cerebral aneurysms. The Comaneci device confers the same benefits as balloon remodeling but without the risks of parent artery occlusion. This alleviates time pressure on the clinician, and could reduce the risk of parent artery thrombosis. Three patients were treated with the Comaneci device. Two patients had acute ruptured posterior communicating aneurysms and one patient was treated electively for a carotico-ophthalmic aneurysm. Excellent occlusion of all three aneurysms was obtained. One patient developed a distal middle cerebral artery clot, that was treated with intravenous aspirin, with minor neurological consequences. These early results show that the Comaneci device can be used to achieve good cerebral aneurysm occlusion. Vessel patency is maintained throughout the procedure with potential advantages over conventional balloon assisted coiling.

Spinal dural arteriovenous fistulas – presentation, management and outcome in a single neurosurgical institution

Abstract Objective. To compare the outcome, with respect to treatment modality, of patients treated with spinal dural arteriovenous fistulas (SDAVF). Method. Retrospective cohort study of patients with SDAVF assessed at a single tertiary referral centre, between 1999 and 2009. Intervention type, pre-/ post-intervention Aminoff–Logue disability score (ALDS) and recurrence rate were obtained from medical records. Results. 26 patients were identified with 23 receiving intervention. All patients initially received super selective angiogram, with 13 undergoing endovascular embolization at this stage, after discussion between the surgeon and interventional radiologist. Six patients who underwent embolization had a recurrence. The remaining 10 patients had fistulas marked during angiography, and were then treated surgically, after discussion. One of these recurred. The difference in recurrence rate between the two intervention types was not statistically significant. Fistulas treated with the embolization material onyx were twice as likely to recur as those treated with the alternative material, histoacryl–lipiodol. There was a statistically significant difference between the modes of intervention in relation to clinical outcome. Surgeries lead to an improvement in neurology, whereas treatment via embolization did not. Neurological improvement was seen in non-recurring cases, however deterioration in neurological function occurred with fistula recurrence. Conclusion. Super selective angiography is effective in defining the relevant vascular anatomy and allows for precise fistula localization during any potential subsequent surgery. Onyx was associated with a higher recurrence rate, suggesting it is less suitable as an embolization material for SDAVF treatment. Surgery appeared to correlate to reversal of neurological impairment seen at presentation, possibly due to a lower recurrence rate. The study is limited by small patient numbers, emphasizing the need for further studies of SDAVF patients.

Accuracy of four-dimensional CT angiography in detection and characterisation of arteriovenous malformations and dural arteriovenous fistulas.

A retrospective review was made to assess the accuracy of four dimensional CT angiogram (4D-CTA) in diagnosis of arteriovenous malformations (AVM) and dural arteriovenous fistulas (DAVF), with catheter-based digital-subtraction angiogram (DSA) being gold standard. 33 pairs of investigations (DSA and 4D-CTA) were performed primarily for suspicion of AVM/DAVF. Based on blinded reports, sensitivity and specificity for detection of AVM/DAVF were 77% (95% CI: 46 - 95%) and 100% (95% CI: 83 - 100%) respectively. Positive predictive value was 100% (95% CI: 69 - 100%) and negative predictive value 87% (95% CI: 66-97%). 4D-CTA is a practical minimally-invasive technique for evaluating cerebrovascular pathologies. There is good agreement between the findings of 4D-CTA and DSA despite the differences in temporal and spatial resolutions. 4D-CTA may obviate the need for DSA in a subgroup of patients who would otherwise have undergone this invasive investigation, which carries a risk of important complications.

Distal access using hyperflexible atraumatic distal tip with optimized proximal stability of the Benchmark intracranial guide catheter for the treatment of cerebral vascular diseases: a technical note

Background A stable guide catheter position within the intracranial vasculature is critical for safe, successful endovascular treatment. Objective To present ourinitial experience with the 0.071 inch inner diameter Benchmark guide catheter used in the treatment of intracranial cerebrovascular pathologies, demonstrating its safety and efficacy. Methods We retrospectively reviewed use of the Benchmark guide catheter from September through December 2014 in the management of various neuroendovascular intracranial pathologies. Clinical performance and complication rates were evaluated, with particular consideration of vessel tortuosity. A total of 62 Benchmarks were used, 47 in the anterior circulation, 10 in the posterior circulation, 4 in the external carotid, and 1 in the venous sinus. The five cases with access to the external carotid and venous sinus were excluded. Results The Benchmark was able to cross at least one 90° turn in 49 (86%) of the 57 patients. Reversal of the catheter was seen in 15% of 47 anterior circulation cases (4 at one 90° turn; 3 at two 90° turns). We report no complications of dissection or thromboembolic events. All guide catheter positions were safely achieved over a 0.035 Terumo stiff glidewire without need for an inner smaller lumen guide catheter for navigation. Conclusions Benchmark is a new guide catheter, with an ideal combination of both hyperflexible, atraumatic distal tip and optimized proximal shaft support to provide stable 6F primary access for a successful neurointerventional procedure. Benchmark can be easily, safely, and consistently positioned in a desired location within intracranial arteries providing a stable position for intervention and adequate angiography.

Novel use of 4D-CTA in imaging of intranidal aneurysms in an acutely ruptured arteriovenous malformation: is this the way forward?

Ruptured arteriovenous malformation (AVM) is a frequent cause of intracranial hemorrhage. The presence of associated aneurysms, especially intranidal aneurysms, is considered to increase the risk of re-hemorrhage. We present two cases where an intranidal aneurysm was demonstrated on four-dimensional CT angiography (time-resolved CT angiography) (4D-CTA). These features were confirmed by digital subtraction angiography (catheter arterial angiogram). This is the first report of an intranidal aneurysm demonstrated by 4D-CTA. 4D-CTA can offer a comprehensive evaluation of the angioarchitecture and flow dynamics of an AVM for appropriate classification and management.

Anomalous cerebral venous sinus drainage

The case discussed is a 58 year old female that presented with sudden onset of headache, a Glasgow Coma Score of 15 and no neurological deficit. Computed tomography (CT) scan of the brain did not show any evidence of haemorrhage. CT angiography revealed a left sided cerebellar ateriovenous malformation with the Digital Subtraction Angiography (DSA) also showing anomalous posterior fossa venous sinus anatomy. In this case the occipital sinus provided the only drainage pathway for both the superior sagittal sinus (SSS) and the straight sinus. Of clinical significance is during the routine method of access to midline posterior fossa surgery the occipital sinus is ligated and divided. This would have resulted in massive venous infarction. Highlighting the importance of reviewing the venous anatomy on radiological images prior to neurosurgical procedures.

Case Report: Traumatic Carotid-Cavernous Fistula.

Carotid-cavernous fistulae (CCFs) are a rare complication of head trauma, with potentially serious consequences. We report the case of a 45-year-old male patient who presented with posttraumatic CCF 2 months after sustaining a head injury. Appropriate imaging in the form of computed tomography of the head, magnetic resonance imaging of the head, and digital subtraction angiography of the intracranial vessels was performed, and the CCF was successfully coil embolized. This resulted in good resolution of the patients symptoms. We discuss the cause, presentation, diagnosis, and treatment of CCFs. Carotid-cavernous fistulae are a rare sequela of craniofacial trauma; therefore, a high index of suspicion must be maintained to establish a diagnosis and prevent serious consequences.