Alan O’Hare

Endovascular repair of posterior communicating artery aneurysms, associated with oculomotor nerve palsy: A review of nerve recovery

Purpose Oculomotor nerve palsy (ONP) is often the presenting symptom in patients with posterior communicating artery (PCOMM) aneurysms with variable recovery of oculomotor nerve function following treatment. In this study we report the ophthalmologic outcome of 20 patients treated by endovascular coiling for PCOMM aneurysm-induced ONP. Methods We performed 230 PCOMM aneurysm endovascular coilings between the years 2006 and 2011, of which 20 cases presented with ONP. We recorded the degree of nerve recovery – complete, partial or none – while also documenting other predictive factors, such as degree of pre-intervention nerve deficit, presence of subarachnoid haemorrhage (SAH), size and location of the PCOMM aneurysm and length of follow-up. Results Of the 20 patients, 9 (45%) presented with complete ONP and 11 (55%) with partial ONP. After an average follow-up period of 16 months, all patients achieved oculomotor nerve recovery; 9 (45%) patients had complete recovery and 11 (55%) patients had partial recovery. Of the 9 patients who presented with complete ONP, 5 (56%) patients made a complete recovery and 4 (44%) made a partial recovery. Of the 11 patients who initially presented with partial ONP, 4 (36%) made a complete recovery and 7 (64%) made a partial recovery. 7 (35%) patients also had a SAH, of whom 3 (43%) made a complete recovery with 4 (57%) making a partial recovery. Conclusions ONP can occur with PCOMM aneurysm with or without SAH. Endovascular coiling is an effective treatment for ONP due to PCOMM aneurysms.

Endovascular thrombectomy beyond 12 hours of stroke onset: a stroke network’s experience of late intervention

Background Selected patients with proximal anterior circulation ischemic stroke who demonstrate limited infarct and sufficient penumbra may benefit from endovascular thrombectomy (EVT) beyond conventional time limits. Objective To perform a retrospective review of all cases of EVT performed at our institution for proximal anterior circulation acute ischemic stroke with onset >12 hours. Materials and methods Patients were assessed with non-contrast CT brain and multiphase CT angiography, with Alberta Stroke Program Early CT Score (ASPECTS) and collateral grade informing patient selection. Data, including patient demographics, workflow, neuroimaging findings, procedural details, recanalization rates, and 90-day functional outcomes, were collected. Results Of the 542 consecutive endovascular thrombectomy cases performed during the study period, 25 (4.6%) were >12 hours from stroke onset. Median age was 69 years (IQR 55–80), median National Institute of Health Stroke Scale score on presentation was 14 (IQR 11–18.5), median ASPECTS was 8 (IQR 8–9), and rate of moderate–good collateral status was 96% (n=24). Median time to groin puncture was 14 hours 40 min (IQR 12 hours 36 min – 16 hours 18 min). Rate of successful recanalization (modified Thrombolysis in Cerebral infarction 2b–3) was 88% (n=22). Rate of functional independence (90-day modified Rankin Scale score 0–2) was 52% (n=13). There were no cases of symptomatic intracranial haemorrhage and 90-day mortality rate was 12% (n=3). Conclusion With the use of ASPECTS and collateral grade to guide patient selection, good functional outcome with acceptable safety parameters may be achieved in patients undergoing EVT beyond 12 hours from stroke onset.

Drip and ship versus direct to endovascular thrombectomy: The impact of treatment times on transport decision-making:

Introduction In ischaemic stroke care, fast reperfusion is essential for disability free survival. It is unknown if bypassing thrombolysis centres in favour of endovascular thrombectomy (mothership) outweighs transport to the nearest thrombolysis centre for alteplase and then transfer for endovascular thrombectomy (drip-and-ship). We use conditional probability modelling to determine the impact of treatment times on transport decision-making for acute ischaemic stroke. Materials and methods Probability of good outcome was modelled using a previously published framework, data from the Irish National Stroke Register, and an endovascular thrombectomy registry at a tertiary referral centre in Ireland. Ireland was divided into 139 regions, transport times between each region and hospital were estimated using Google’s Distance Matrix Application Program Interface. Results were mapped using ArcGIS 10.3. Results Using current treatment times, drip-and-ship rarely predicts best outcomes. However, if door to needle times are reduced to 30 min, drip-and-ship becomes more favourable; even more so if turnaround time (time from thrombolysis to departure for the endovascular thrombectomy centre) is also reduced. Reducing door to groin puncture times predicts better outcomes with the mothership model. Discussion This is the first case study modelling pre-hospital transport for ischaemic stroke utilising real treatment times in a defined geographic area. A moderate improvement in treatment times results in significant predicted changes to the optimisation of a national acute stroke patient transport strategy. Conclusions Modelling patient transport for system-level planning is sensitive to treatment times at both thrombolysis and thrombectomy centres and has important implications for the future planning of thrombectomy services.

Unruptured Basilar Tip Aneurysm with Internal Septation: Coiling Implications?

An internal septum within a basilar artery aneurysm is an infrequent anomaly and is very rarely reported in the literature. We report a 62-year-old lady that was incidentally diagnosed with basilar tip aneurysm. Further imaging with magnetic resonance imaging (MRI) revealed internal septation within this aneurysm which was later confirmed with digital subtraction angiography (DSA). She underwent coil embolisation, which involved technical manipulation of the microcatheter and the balloon to enable coiling of each separate aneurysm compartment. We present this case to illustrate the effect of this anatomical variation on the selection of endovascular treatment strategy.

Decreasing incidence of subarachnoid hemorrhage

Objective To determine the incidence and trends in subarachnoid hemorrhage in Ireland using data from a national database. Materials and methods We performed a retrospective nationwide query of the Irish Hospital In-patient Enquiry System (HIPE). This is a national database of all in-patient activity in acute public hospitals in Ireland. Each HIPE entry records one episode of in-patient care. The study period ranged from 1997 to 2015. Population data was obtained from the Irish Central Statistics Office, and the annual prevalence of smoking from the Irish National Tobacco Control Office. We were therefore able to calculate both crude annual acute subarachnoid hemorrhage (SAH) incidence rates, as well as population-standardized rates, and compared them with trends in the annual smoking rates. Results The mean number of SAH cases per year is 549, with 465 cases in 1997 and 517 in 2015 (range: 465–624). The absolute incidence of SAH, therefore, remained relatively stable. Due to population increases over time, the population-adjusted rate of SAH therefore decreased, from 126.9/million people/year in 1997 to 111.5/million people/year in 2015. Nationally, there was a decrease in smoking prevalence, from 31% in 1998 to 19.2% in 2015. There was a statistically significant correlation between decreasing smoking rates and decreasing population-adjusted incidence of SAH (P=<0.0001). Conclusions Our data suggests that the incidence of non-traumatic subarachnoid hemorrhage in our population appears to be decreasing, a decrease which is correlated with decreasing smoking rates. This provides important data both in terms of the epidemiology of SAH, as well as the possible role of public-health interventions in tackling both smoking and declining rates of SAH.

Balloon-assisted coil embolization (BACE) of a wide-necked renal artery aneurysm using the intracranial scepter C compliant occlusion balloon catheter

BackgroundTrue renal artery aneurysms (TRAA) are an uncommon pathology, with a prevalence of less than 1%. Treatment of TRAAs is generally recommended when the aneurysm sac equals or exceeds 2cms. Both wide-necked and main renal artery branch aneurysms represent a challenge for conventional endovascular coil embolization due to the risk of coil migration.Main bodyIntra-procedural remodeling of the aneurysm neck using Balloon Assisted Coil Embolization (BACE) is considered a suitable alternative in challenging cases of visceral artery aneurysms.Short ConclusionWe describe the novel use of the Scepter C (MicroVention Terumo, Tustin, CA) compliant double lumen neurovascular occlusion balloon in the treatment of a wide-necked branch TRAA in a patient with a solitary kidney.

Images in Neuroscience: QuestionSudden onset bilateral lower limb weakness in a female patient with no significant past medical history: question

Spinal cord infarction is a relatively rare condition, with the most common type being anterior spinal artery syndrome, presenting with acute bilateral weakness/paraparesis, impaired spinothalamic sensation and usually preserved deep sensation with or without respiratory dysfunction [1]. Common aetiologies include atherosclerosis, aortic aneurysm, surgery or dissection, and hypercoagulability states. Hence, spinal cord infarction arising from an atherosclerotic pathogenesis has a propensity to occur in elderly and vasculopath patients [1–3]. The classical MRI features of spinal cord infarction are central T2 hyperintensity without significant cord expansion or contrast enhancement. Although usually technically difficult to image, if possible, diffusion-weighted imaging demonstrates corresponding abnormal restricted diffusion, as in acute cerebral infarction [2]. These MRI changes were evident in our patient with H-shaped T2 hyperintensity demonstrated on the axial image (Fig. 1A of Images in Neuroscience: Question) which was confined to the grey matter of the cord, consistent with the known particular sensitivity of the neuronal perikaryon to hypoxia. The striking diffuse apparent diffusion coefficient hypointensity along the cord which was congruent with increased signal intensity demonstrated on diffusion weighted imaging, is also consistent with abnormal restricted diffusion indicative of an acute ischaemic process (Fig. 1B, Fig. 1C from Images in Neuroscience: Question). The CT aortogram (Fig. 1A) demonstrates severe calcific atherosclerosis throughout the aorta and its major abdominal branches, which is a common underlying cause of cord infarction in this age group [4]. Our patient had clinical and radiological findings consistent with diffuse cord infarction which is an unfortunate condition with little prospect of recovery, as occurred in this patient [1,5].

An audit of out of hours MRI scanning at a tertiary care referral hospital

The aim of this audit was to record the numbers of MRI scans performed out of hours or on-call in a busy tertiary care referral hospital. As this service continues to increase, we look at the trends and patterns in referrer pathways, the clinical indications for these studies, the types of studies performed, the results of these studies and the impact on patient management.