Endovascular therapy for acute stroke in children: age and size technical limitations.

Endovascular therapies for acute childhood stroke remain controversial and little evidence exists to determine the minimum age and size cut-off for thrombectomy in children. Despite this, an increasing number of reports suggest feasibility of thrombectomy in at least some children by experienced operators. When compared with adults, technical modifications may be necessary in children owing to differences in vessel sizes, tolerance of blood loss, safety of contrast and radiation exposure, and differing stroke etiologies. We review critical considerations for neurologists and neurointerventionalists when treating pediatric stroke with endovascular therapies. We discuss technical factors that may limit feasibility of endovascular therapy, including size of the femoral and cervicocerebral arteries, which contributes to vasospasm risk. The risk of femoral vasospasm can be assessed by comparing catheter outer diameter with estimated femoral artery size, which can be estimated based on the child's height. We review evidence supporting specific strategies to mitigate cervicocerebral arterial injury, including technique (stent retrieval vs direct aspiration) and device size selection. The importance of and strategies for minimizing blood loss, radiation exposure, and contrast administration are reviewed. Attention to these technical limitations is critical to delivering the safest possible care when thrombectomy is being considered for children with acute stroke.

Venous sinus stenting as a treatment approach in patients with idiopathic intracranial hypertension and encephaloceles.

BACKGROUND: Stenosis of a dural venous sinus is the most common cause of idiopathic intracranial hypertension (IIH) and can be classified as either intrinsic or extrinsic. Intrinsic stenoses are characterized by a focal filling defect within the sinus secondary to an enlarged arachnoid granulation or fibrous septa while extrinsic stenoses tend to be long and smooth-tapered and are most commonly secondary to external compression from the adjacent brain parenchyma. Brain herniations, or encephaloceles, into arachnoid granulations in dural venous sinuses have rarely been reported in the literature in patients with IIH. We propose that dural venous sinus stenting (VSS) may be a safe and effective treatment approach in patients with an encephalocele and IIH. METHODS: We retrospectively analyze three cases of patients with encephalocele who underwent VSS for treatment of medically refractory IIH at our institution. RESULTS: One patient underwent stenting ipsilateral and two patients underwent stenting contralateral to the side of their encephaloceles. No technical related issues or complications occurred during either of the three stenting procedures. Two out of the three patients had complete resolution in their IIH-related symptoms and normalization of cerebrospinal (CSF) pressures shortly after stenting. We await clinical follow-up in the third patient. CONCLUSIONS: Our results suggest that VSS is a technically feasible and effective approach in treating patients with medically refractory IIH and encephaloceles.

Brain Arteriovenous Malformation Recurrence After Apparent Microsurgical Cure: Increased Risk in Children Who Present With Arteriovenous Malformation Rupture.

BACKGROUND AND PURPOSE: Do children have an increased risk for brain arteriovenous malformation (AVM) recurrence compared with adults and does this risk vary depending on initial presentation with AVM rupture? METHODS: We retrospectively studied 115 patients initially presenting with brain AVM under age 25 years who underwent complete surgical resection of the AVM as documented by digital subtraction angiography (DSA) and had delayed follow-up DSA to evaluate for AVM recurrence after apparent initial cure. RESULTS: The mean time from baseline DSA to follow-up DSA was 2.3 years, ranging from 0 to 15 years. Twelve patients (10.4% of the 115 patient cohort and 16.7% of 72 patients with hemorrhage at initial presentation) demonstrated AVM recurrence on follow-up DSA. All patients with recurrence initially presented with intracranial hemorrhage, and intracranial hemorrhage was a significant predictor of recurrence (log rank P=0.037). Among patients with initial hemorrhage, the 5-year recurrence rate was 17.8% (95% CI, 8.3%-35.7%). All recurrences occurred in patients who were children at the time of their initial presentation; the oldest was 15 years of age at the time of initial AVM surgery. The 5-year recurrence rate for children (0-18 years of age) with an initial presentation of hemorrhage was 21.4% (95% CI, 10.1%-41.9%). Using Cox regression, we found the risk of AVM recurrence decreased by 14% per each year increase in age at the time of initial surgical resection (hazard ratio=0.86 [95% CI, 0.75-0.99]; P=0.031). CONCLUSIONS: There is a high rate of recurrence of apparently cured brain AVMs in children who initially present with AVM rupture. Imaging follow-up is warranted to prevent re-rupture.

Mechanical Thrombectomy for Acute Ischemic Stroke: Considerations in Children.

The use of mechanical thrombectomy for the treatment of acute childhood arterial ischemic stroke with large vessel occlusion is increasing, with mounting evidence for its feasibility and safety. Despite this emerging evidence, clear guidelines for patient selection, thrombectomy technique, and postprocedure care do not exist for the pediatric population. Due to unique features of stroke in children, neurologists and interventionalists must consider differences in patient size, anatomy, collateral vessels, imaging parameters, and expected outcomes that may impact appropriate patient selection and timing criteria. In addition, different causes of stroke and comorbidities in children must be considered and may alter the safety and efficacy of thrombectomy. To optimize the success of endovascular intervention in children, a multidisciplinary team should take into account these nuanced considerations when determining patient eligibility, developing a procedural approach, and formulating a postprocedure neurological monitoring and therapeutic plan.

Endovascular Stroke Interventions: Procedural Complications and Management.

Endovascular mechanical thrombectomy has evolved significantly and has become the mainstay and most effective currently available treatment for acute ischemic stroke patients due to large vessel occlusion. Mechanical thrombectomy is presently performed using a stent retriever or stent-like device, an aspiration catheter, or a combination of the two. Much of the literature has focused on the benefits of endovascular mechanical thrombectomy with only limited data about procedural complications and management. Awareness of risk factors and early recognition of these complications can potentially reduce complication rates, improve management, and yield better overall outcomes. In this review, the authors present a description of intraprocedural complications and strategies to prevent and treat these complications.