Complications of cerebral angiography in children younger than 3 years of age

Systematic Review and Case of Thrombectomy for Pediatric Stroke Due to Myxoma Embolism

BACKGROUND

Stroke presentation secondary to a cardiac myxoma thromboembolism is rare in the pediatric population. Because of such rarity, the reported cases in the literature are primarily case reports. Additionally, general pediatric stroke management lacks evidence-based guidelines because of its low incidence and lack of clinical trials. In pediatric strokes identified from a cardiac myxoma, the incidence favors boys with the classical presentation of unilateral weakness and aphasia. We present a pediatric patient who presented with strokelike symptoms secondary to an intracranial embolus from a previously undiagnosed cardiac myxoma.

METHODS

We performed a systematic review by searching PubMed, Google Scholar, Web of Science, and Embase databases for cases of pediatric myxoma causing stroke (n = 2431) and identified 19 reported uses of surgical management in treating pediatric patients who present with stroke symptoms secondary to a cardiac myxoma thromboembolism.

RESULTS

The most common imaging modality was magnetic resonance imaging in 42% of cases, computed tomography in 36.8%, followed by computed tomography angiography in 31.6% of cases. Of these 19 children treated with procedures, 36.8% of pediatric patients aged between 4 and 14 years underwent neurosurgery (n = 7).

CONCLUSIONS

We describe an urgent mechanical thrombectomy and share preoperative and postoperative images and pathology slides confirming a stroke from myxoma origin. We provide added insight in the safe use of mechanical thrombectomy as treatment for pediatric strokes secondary to a thromboembolism.

Salvageable Intra-stent Coil Embolization Treatment for Spinal Dural Arteriovenous Fistula in a Child

Spinal dural arteriovenous fistulae (SDAVF) are rare diseases that exhibit abnormal connections between arteries and veins. They are even rarer in the pediatric population and pose diagnostic and treatment challenges for physicians. Its presentation varies depending on the site and size of the SDAVF. Multiple management options are available, which are usually tailored depending on the patient's condition. Here, we present a rare case of SDAF in a four-year-old girl who initially presented with bilateral lower limb weakness. The patient was then treated successfully using primary major fistula point stenting and intra-stent coiling, with complete closure achieved. Full recovery was achieved over the course of follow-ups. The deep analysis of SDAVF, its classification, and the utilization of the best available endovascular tools by a dedicated neurovascular team offer the best outcome in dealing with complex spinal neurovascular pathologies.

Magnetic Resonance Imaging/Angiography Versus Catheter Angiography for Annual Follow-up of Pediatric Moyamoya Patients: A Cost Outcomes Analysis

BACKGROUND

Digital subtraction angiography (DSA) assesses revascularization in pediatric moyamoya patients after surgery, but MRI and angiography (MRI/A) may provide comparable data.

OBJECTIVE

To evaluate DSA and MRI/A with respect to clinical utility in postoperative follow-up, complication profile, and relative cost at 1 year.

METHODS

All pediatric moyamoya patients who received bilateral indirect revascularization between 2011 and 2020 were retrospectively reviewed at 1 institution. Patients who underwent MRI/A-only, DSA-only, or both after 1 year were compared.

RESULTS

Eighty-two patients were included. At 1 year, patients who underwent either MRI/A (n = 29) or DSA (n = 40) had no significant differences in detection rate of new at-risk hypovascular territories (6.9% vs 2.5%, P = .568) or need for subsequent revascularization beyond the mean 40 ± 24-month follow-up period (3.4% vs 5.0%, P > .9). Among patients who underwent both MRI/A and DSA (n = 13), both studies identified the same at-risk territories. No patients experienced MRI/A-related complications, compared with 3 minor DSA-related complications. The use of MRI/A yielded a 6.5-fold reduction in cost per study vs DSA at 1 year.

CONCLUSION

Using DSA to follow moyamoya patients after indirect revascularization is generally safe but associated with a low rate of minor complications and a 6.5-fold greater financial cost relative to MRI/A. These data support changing practice to eliminate the use of DSA when following routine bilateral moyamoya cases in the absence of clinical symptoms or specific concerns. Using MRI/A as the primary postoperative follow-up modality in this select population provides noninferior care and greater patient access, while reducing cost and potentially decreasing risk.

Recurrence of brain arteriovenous malformations in pediatric patients: a long-term follow-up study

BACKGROUND

Previously thought to be congenital, AVMs have shown evidence of de-novo formation and continued growth, thus shifting thoughts on their pathophysiology. Pediatric AVM patients have been reported to be more prone to develop AVM recurrence after a seemingly complete cure. Therefore, we assessed the risk of AVM treated in childhood to recur in adulthood after a long-term follow-up in our own cohort.

METHODS

Control DS-angiography was arranged during 2021-2022 as part of a new protocol for all AVM patients who were under 21 years of age at the time of their treatment and in whom the treatment had occurred at least five years earlier. Angiography was offered only to patients under 50 years of age at the time of the new protocol. The complete eradication of AVM after the primary treatment had been originally confirmed with DSA in every patient.

RESULTS

A total of 42 patients participated in the late DSA control, and 41 of them were included in this analysis after excluding the patient diagnosed with HHT. The median age at the time of admission for AVM treatment was 14.6 (IQR 12-19, range 7-21 years) years. The median age at the time of the late follow-up DSA was 33.8 years (IQR 29.8-38.6, range 19.4-47.9 years). Two recurrent sporadic AVMs and one recurrent AVM in a patient with hereditary hemorrhagic telangiectasia (HHT) were detected. The recurrence rate was 4.9% for sporadic AVMs and 7.1% if HHT-AVM was included. All the recurrent AVMs had originally bled and been treated microsurgically. The patients with sporadic AVM recurrence had been smoking their whole adult lives.

CONCLUSIONS

Pediatric and adolescent patients are prone to develop recurrent AVMs, even after complete AVM obliteration verified by angiography. Therefore, imaging follow-up is recommended.

A deceptive mass on neonatal ultrasound and a fetal brain MRI-confirmed complex dural arteriovenous fistula postnatally: illustrative case

BACKGROUND

Dural arteriovenous fistulas (dAVFs) are direct, aberrant connections between dural arteries and cerebral veins. In neonates, delayed diagnosis results in grim outcomes. Treatment involves endovascular management because of its success and tolerability. Here, the authors present a case of a complex dAVF initially recognized with an in utero neurosonogram and fetal magnetic resonance imaging (MRI).

OBSERVATIONS

A 21-week fetal ultrasound of a nonspecific brain mass was confirmed with fetal MRI as a 2.7-cm T1-hyperintense posterior fossa mass. Although a large flow void in the left middle cranial fossa was present, postnatal computed tomography angiography ultimately revealed a high-flow dAVF communicating with the left transverse sinus. In the early postnatal period, the patient developed hydrocephalus. After successful partial embolization, 6-week postangiogram brain MRI indicated disease progression with the development of a venous varix causing brainstem compression. Repeat embolization resulted in complete cessation of early venous drainage.

LESSONS

Neonatal dAVFs are exceedingly rare and result in futile outcomes; however, detection in utero is possible. Although definitive therapy must be performed postnatally, constant monitoring and early delivery can prevent complications. Attention to fetal ultrasound is essential, and knowledge of fetal MRI in the detection of these complex lesions can significantly improve outcomes.

Ruptured AComA aneurysm and asymptomatic bilateral ACA vasospasm in an infant: surgical case report

Intracranial aneurysms (IAs) are localized dilations of the cerebral vasculature, representing the leading cause for non-traumatic subarachnoid hemorrhage and an important source of morbidity and mortality. Despite it being a frequent pathology and most often diagnosed incidentally, IAs in infants are a very rare occurrence, and the ruptured variant is exceptional. A 4-month-old boy with a negative family history was brought to our department because of several episodes of incoercible vomiting and fever. Upon examination, the child was somnolent, without any noticeable deficit. Transfontanellar ultrasonography and CT angiography revealed a ruptured aneurysm of the anterior communicating artery (AComA), whereas the pre-clipping MRI showed thin, almost angiographically invisible anterior cerebral arteries (ACAs) on both sides due to vasospasm. We intervened surgically by placing an external ventricular shunt in an emergency setting, followed by clipping of the IA in a delayed manner. The child was discharged a month after admission with no deficit, despite the paradoxical aspect of the ACA. Ruptured IAs can be safely treated via microsurgery, even in infants. However, this requires a great amount of experience and surgical expertise. Furthermore, the lack of proper management would most likely result in a severe deficit in the long term. Lastly, the lack of visibility of the ACA on angiographic studies may not have neurological consequences if they occur in this age group.

Safety of pediatric cerebral angiography

OBJECTIVE

Catheter-based cerebral angiography is commonly used for neurovascular diagnosis in children. In this work, the authors aimed to quantify the complication rate of cerebral angiography in children, characterize these complications, and identify risk factors for complications.

METHODS

Relevant clinical data were retrospectively obtained for 587 consecutive cerebral angiography procedures performed in 390 children from March 2002 to March 2020. Complications were categorized as neurological or nonneurological, and severity was graded using a standard schema. Incidences of complications were reported as point estimates. Associations between risk factors and complications were characterized in univariate analysis using the two-tailed Fisher exact test and in multivariate analysis using multiple logistic regression with bidirectional elimination based on the Akaike information criterion. In both univariate and multivariate analyses, statistical significance was corrected for multiple comparisons using the Benjamini-Hochberg method.

RESULTS

Complications occurred in 6.5% of procedures, including neurological complications in 1.9% and nonneurological complications in 4.8%. Permanent deficits occurred in only 0.2% of cases. Overall, 0.5% of procedures resulted in major complications, while 6.0% resulted in minor complications. Female sex and a history of hypertension or ischemic stroke were associated with an increased risk of complications, while femoral artery access was associated with a decreased risk of complications.

CONCLUSIONS

Pediatric cerebral angiography was shown to have a low rate of major or permanent complications. Children who were female and those with a history of hypertension or ischemic stroke were shown to be at higher risk of complications, while the use of femoral access carried a lower risk of complications.

Acute StrokeTreatment in Children: Are Adult Guidelines Applicable?

Purpose of this Review

This article provides an overview into acute treatments in stroke which are widely studied and available for adults and their applicability in the pediatric population.

Recent Findings

Arterial ischemic stroke is an important cause of morbidity and mortality in the pediatric population. Neurological deficits and etiologies are age-dependent and more challenging to diagnose than in the adult population. Advancements in imaging and treatment modalities including increased treatment windows in acute stroke have led to improvement in the diagnosis and management of pediatric arterial ischemic disease. Accordingly, hyperacute treatments, such as endovascular therapy, are becoming increasingly available in an attempt to improve outcomes in children.

Summary

Significant scientific and technological advances have transformed the hyperacute treatment of stroke in the recent years, allowing for improvement in the diagnosis and treatment of cerebrovascular pathologies in children. Optimization in the approach, and validation of existing stroke pathways/protocols is expected to further advance acute stroke therapy in pediatric patient care. Given that the lifelong individual, family, and societal burden of acute stroke is likely to be greater than in adults because infants and children surviving stroke live more years with disability, we must be knowledgeable about this pathology and the medical and therapeutic options available for this unique population as detailed in this review.

Low profile sheaths in pediatric neurointervention: a multicenter experience

BACKGROUND

Pediatric neurointervention is challenged by the appropriateness of adult catheters and devices. This multicenter report on the smallest groin access sheaths offers technical notes and clinical outcomes in the pediatric neurointerventional population.

METHODS

All pediatric neurointerventional cases from 2019 to 2021 were reviewed for use of a 3.3F Pediavascular or a 4F Merit Prelude Ideal low profile sheath. Hospital records were reviewed for complications and technical notes and compared with arterial groin access with the 4F Terumo Pinnacle in infants less than 1 year old, before the low profile sheaths at one author's institution were introduced.

RESULTS

From January 1, 2019 to March 31, 2021 there were 347 procedures performed at Boston Children's Hospital and University of Wisconsin. Forty-four procedures in 26 patients were identified in which a 3.3F (38 cases, 20 patients) or 4F (6 cases, 6 patients) sheath was used. The average age was 2.2 years (1.5 days to 18 years). Retinoblastoma intra-arterial chemotherapy infusion (18 of 44) was the most common indication. The remaining procedures comprised vein of Galen embolization (12), diagnostic cerebral angiography (13), and one preoperative tumor embolization. Morbidity included a groin hematoma and decreased pulses (4.5%). No major groin complications occurred. There was no statistically significant difference compared with the historical cohort (132 procedures), which had seven instances of decreased pulses (5.3%, p>0.05).

CONCLUSION

The 3.3F Pediavascular and 4F Merit Prelude Ideal sheaths are easily incorporated into the pediatric neurointerventionalist's armamentarium for infants and readily accommodate various microcatheters for distal embolization and catheterization.

Transradial Neuroendovascular Procedures in Adolescents: Initial Single-Center Experience

BACKGROUND AND PURPOSE

The feasibility and safety of transradial angiography is not established outside the adult literature. The objective of this study was to assess the feasibility and safety of transradial access for neuroangiography in adolescents.

MATERIALS AND METHODS

A retrospective case-control study was performed, comparing transradial neuroendovascular procedures in adolescents (age range, 10-18 years) with an age- and procedure-matched cohort of transfemoral neuroendovascular procedures. Clinical and procedural details, including type of procedure, conversion rate, fluoroscopy time, radiation dose, complications, and readmissions, were reported by descriptive statistics or measures of central tendency and compared using a t test or nonparametric equivalent. A P value < .05 was considered statistically significant.

RESULTS

Twenty adolescents (mean age, 14.6 [SD, 1.7] years, M/F ratio = 9:11) who underwent transradial neuroangiography were compared against 20 adolescents (mean age, 14.4 [SD, 2.1 ] years, M/F ratio = 12:8) who underwent transfemoral neuroangiography. We found no significant difference in procedural success (0% conversion rate), fluoroscopy times (33.7 [SD, 40.2] minutes versus 23.3 [SD, 26.2] minutes, P = .34) and radiation dose (150.9 [SD, 133.7] Gy×cm² and 122.9 [SD, 79.7] Gy×cm,² P = .43) There were 2 self-limiting postprocedural complications in the transradial group. There were no major hemorrhages, need for further interventions, or readmissions in either group.

CONCLUSIONS

The benefits of transradial angiography described for adults can likely be safely extended to adolescents. These are important data before transitioning to smaller children and should be prospectively evaluated in a larger cohort.

Long Vascular Sheaths for Transfemoral Neuroendovascular Procedures in Children

PURPOSE

To evaluate the safety and efficacy of long vascular sheaths for transfemoral neuroendovascular procedures in children.

MATERIALS AND METHODS

A retrospective evaluation of transfemoral neuroendovascular procedures in children <18 years, using long sheaths was undertaken analyzing procedure type, fluoroscopic times, technical success, access site and systemic complications. Twenty-seven consecutive procedures were included over a 2-year period. Mean age was 8.4 years (standard deviation [SD] 6.3) (range 17.0 months-16.3 years).

RESULTS

Patients were 44% female and mean weight was 35.0 kg (SD 22.8) (range 9.8-72.2 kg). A third of the procedures were performed in ≤15 kg children. The most common procedure was for embolization (n=13, 48.1%) and the most common indication was dual microcatheter technique (52%). The most common device used was the 5 Fr Cook Shuttle sheath. Mean fluoroscopy time was 61.9 minutes (SD 43.1). Of these procedures, 93% were technically successful. Femoral vasospasm, when present, was self-limiting. Complications (3/27, 11.1%) included groin hematoma (n=1), neck vessel spasm that resolved with verapamil (n=1), and intracranial thromboembolism (n=1), with no significant difference between the ≤15 kg and >15 kg subcohorts. There were no aorto-femoro-iliac or limb-ischemic complications.

CONCLUSION

Long vascular sheaths without short femoral sheaths can be safely used for pediatric neuroendovascular procedures as they effectively increase inner diameter access without increasing the outer sheath diameter. This property increases the range of devices used and intracranial techniques that can be safely performed without arterial compromise, thus increasing the repertoire of the neurointerventionist.

Spinal arteriovenous malformation in a pediatric patient with a history of congenital syphilis: a case report

Background

Spinal arteriovenous malformations in children are extremely rare and pose great risk for intraoperative hemorrhage. Congenital syphilis sometimes presents with vascular symptoms, however, there is little published on patients with a history of congenital syphilis presenting with spinal arteriovenous malformations.

Case presentation

A 15-month-old female with a history of congenital syphilis presented with urinary retention, fever, and subacute onset of paraplegia. MRI showed a lesion at T8-L1, angiogram was performed which confirmed the presence of a complex type IVc arteriovenous malformation and fistula from Artery of Adamkiewicz at L1-L2. It also showed peri medullary dilated veins and a pseudoaneurysm that compressed the spinal cord at T8-T10. Somatosensory evoked potentials and motor-evoked potentials were not recordable on the bilateral lower extremities prior to surgery. Once the patient was optimized for surgery, osteoplastic laminotomies from T6-T12 were performed. The dura was opened and the intradural, intramesenchymal hematoma was evacuated. There were two episodes of brisk arterial bleeding with hypotension during resection of the hematoma. The patient was taken to the angiography suite from the OR to successfully coil the large aneurysm. Intraoperative spinal cord monitoring remained undetectable in the bilateral lower extremities. The patient’s paraplegia remained unchanged from preoperative presentation.

Conclusion

Congenital syphilis may present with vascular changes that might impact surgical approaches and treatment outcomes in patients with spinal arteriovenous malformations. Preparation for massive transfusion and intraoperative monitoring are imperative in ensuring a safe perioperative experience.

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.

Emergent surgical embolectomy for middle cerebral artery occlusion related to cerebral angiography followed by neck clipping for an unruptured aneurysm in the anterior communicating artery

Background:

Intracranial embolism related to cerebral angiography is rare but one of the complications of the procedure. However, the standard management of acute intracranial embolism for this etiology has not been established, and there have been very few reports in the past.

Case Description:

A 68-year-old male was incidentally found to have an unruptured aneurysm of anterior communicating artery (ACoA). Immediately after the cerebral angiography for the purpose of detailed examination of the aneurysm, the right partial hemiparalysis and mild aphasia developed. Magnetic resonance imaging/angiography (MRI/A) revealed an occlusion in the peripheral part of the left middle cerebral artery (MCA). Due to the existence of magnetic resonance angiography-diffusion mismatch, emergent craniotomy was immediately performed to remove intra-arterial thrombus. We also performed clipping for an unruptured ACoA aneurysm with this approach. Postoperative MRI/A showed that the occluded artery was recanalized and a slight infarction was observed in the left cerebral hemisphere. The patient was discharged on foot and followed at outpatient clinic over 4 years without no neurological deficit.

Conclusion:

Emergent surgical embolectomy for distal MCA occlusion related to cerebral angiography followed by neck clipping for an unruptured aneurysm of the ACoA was successful in treating acute occlusion of the peripheral part of the MCA in a patient with an unruptured aneurysm. As there are few similar cases, there is controversy about the best management, but this surgical method can be a safe and effective treatment.

ACR Appropriateness Criteria® Cerebrovascular Disease-Child

Stroke is an uncommon but an important and under-recognized cause of morbidity and mortality in children. Strokes may be due to either brain ischemia or intracranial hemorrhage. Common symptoms of pediatric acute stroke include headache, vomiting, focal weakness, numbness, visual disturbance, seizures, and altered consciousness. Most children presenting with an acute neurologic deficit do not have an acute stroke, but have symptoms due to stroke mimics which include complicated migraine, seizures with postictal paralysis, and Bell palsy. Because of frequency of stroke mimics, in children and the common lack of specificity in symptoms, the diagnosis of a true stroke may be delayed. There are a relatively large number of potential causes of stroke mimic and true stroke. Consequently, imaging plays a critical role in the assessment of children with possible stroke and especially in children who present with acute onset of stroke symptoms. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Pediatric intracranial arteriovenous shunts: Advances in diagnosis and treatment

Pediatric intracranial arteriovenous shunts (IAVSs) comprise a wide range of lesions, including pial arteriovenous malformation (AVM) and arteriovenous fistula (AVF), dural arteriovenous fistula (DAVF) and vein of Galen aneurysmal malformation (VGAM). We provide an overview of pediatric IAVSs, encompassing both diagnosis and endovascular treatment. We include references from pertinent literature and representative cases from our hospital. Pediatric IAVS are frequently associated two broader conditions, such as capillary malformation-arteriovenous malformation (CM-AVM) and hereditary hemorrhagic telangiectasia (HHT). These conditions and the associated genetic mutations have only recently been described. Their impact on the brain will be different in the prenatal period, in neonates, in infants, and in children, with variable symptoms according to each age group and the current strategies of endovascular treatment in the management of these vascular lesions will be discussed. This review could improve the understanding of pediatric IAVSs and their diagnosis and treatment.

Mechanical thrombectomy in pediatric stroke: systematic review, individual patient data meta-analysis, and case series

OBJECTIVE

The role of mechanical thrombectomy in pediatric acute ischemic stroke is uncertain, despite extensive evidence of benefit in adults. The existing literature consists of several recent small single-arm cohort studies, as well as multiple prior small case series and case reports. Published reports of pediatric cases have increased markedly since 2015, after the publication of the positive trials in adults. The recent AHA/ASA Scientific Statement on this issue was informed predominantly by pre-2015 case reports and identified several knowledge gaps, including how young a child may undergo thrombectomy. A repeat systematic review and meta-analysis is warranted to help guide therapeutic decisions and address gaps in knowledge.

METHODS

Using PRISMA-IPD guidelines, the authors performed a systematic review of the literature from 1999 to April 2019 and individual patient data meta-analysis, with 2 independent reviewers. An additional series of 3 cases in adolescent males from one of the authors' centers was also included. The primary outcomes were the rate of good long-term (mRS score 0-2 at final follow-up) and short-term (reduction in NIHSS score by ≥ 8 points or NIHSS score 0-1 at up to 24 hours post-thrombectomy) neurological outcomes following mechanical thrombectomy for acute ischemic stroke in patients < 18 years of age. The secondary outcome was the rate of successful angiographic recanalization (mTICI score 2b/3).

RESULTS

The authors' review yielded 113 cases of mechanical thrombectomy in 110 pediatric patients. Although complete follow-up data are not available for all patients, 87 of 96 (90.6%) had good long-term neurological outcomes (mRS score 0-2), 55 of 79 (69.6%) had good short-term neurological outcomes, and 86 of 98 (87.8%) had successful angiographic recanalization (mTICI score 2b/3). Death occurred in 2 patients and symptomatic intracranial hemorrhage in 1 patient. Sixteen published thrombectomy cases were identified in children < 5 years of age.

CONCLUSIONS

Mechanical thrombectomy may be considered for acute ischemic stroke due to large vessel occlusion (ICA terminus, M1, basilar artery) in patients aged 1-18 years (Level C evidence; Class IIb recommendation). The existing evidence base is likely affected by selection and publication bias. A prospective multinational registry is recommended as the next investigative step.

Ferumoxytol-enhanced MRI for surveillance of pediatric cerebral arteriovenous malformations

OBJECTIVE

Children with intracranial arteriovenous malformations (AVMs) undergo digital DSA for lesion surveillance following their initial diagnosis. However, DSA carries risks of radiation exposure, particularly for the growing pediatric brain and over lifetime. The authors evaluated whether MRI enhanced with a blood pool ferumoxytol (Fe) contrast agent (Fe-MRI) can be used for surveillance of residual or recurrent AVMs.

METHODS

A retrospective cohort was assembled of children with an established AVM diagnosis who underwent surveillance by both DSA and 3-T Fe-MRI from 2014 to 2016. Two neuroradiologists blinded to the DSA results independently assessed Fe-enhanced T1-weighted spoiled gradient recalled acquisition in steady state (Fe-SPGR) scans and, if available, arterial spin labeling (ASL) perfusion scans for residual or recurrent AVMs. Diagnostic confidence was examined using a Likert scale. Sensitivity, specificity, and intermodality reliability were determined using DSA studies as the gold standard. Radiation exposure related to DSA was calculated as total dose area product (TDAP) and effective dose.

RESULTS

Fifteen patients were included in this study (mean age 10 years, range 3-15 years). The mean time between the first surveillance DSA and Fe-MRI studies was 17 days (SD 47). Intermodality agreement was excellent between Fe-SPGR and DSA (κ = 1.00) but poor between ASL and DSA (κ = 0.53; 95% CI 0.18-0.89). The sensitivity and specificity for detecting residual AVMs using Fe-SPGR were 100% and 100%, and using ASL they were 72% and 100%, respectively. Radiologists reported overall high diagnostic confidence using Fe-SPGR. On average, patients received two surveillance DSA studies over the study period, which on average equated to a TDAP of 117.2 Gy×cm2 (95% CI 77.2-157.4 Gy×cm2) and an effective dose of 7.8 mSv (95% CI 4.4-8.8 mSv).

CONCLUSIONS

Fe-MRI performed similarly to DSA for the surveillance of residual AVMs. Future multicenter studies could further investigate the efficacy of Fe-MRI as a noninvasive alternative to DSA for monitoring AVMs in children.

Use of a radial artery 'slender' sheath for facilitating transfemoral arterial access for neuroendovascular embolization in a very young infant

Pediatric neuroendovascular procedures are increasingly performed as several studies have shown the safety of these interventions. In the literature, an upper limit of 4 French catheter size is conventionally used for femoral access in neuroangiography of very young infants. However, this constraint in luminal size may not allow for more complex procedures. We present the previously unreported use of a radial 5 French slender catheter with ultrathin walls for femoral access for aneurysm embolization in a 3-month-old boy presenting with left M2 aneurysm rupture.

Emergency Neurological Life Support: Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a subset of stroke due to spontaneous bleeding within the parenchyma of the brain. It is potentially lethal, and survival depends on ensuring an adequate airway, proper diagnosis, and early management of several specific issues such as blood pressure, coagulopathy reversal, and surgical hematoma evacuation for appropriate patients. ICH was chosen as an Emergency Neurological Life Support (ENLS) protocol because intervention within the first hours may improve outcome, and it is critical to have site-specific protocols to drive care quickly and efficiently.

Safety of Diagnostic Cerebral and Spinal Digital Subtraction Angiography in a Developing Country: A Single-Center Experience

BACKGROUND

Digital subtraction angiography (DSA) remains the gold standard imaging modality for cerebrovascular disorders. In contrast to developed countries, the safety of the procedure is not extensively reported from the developing countries. Herein, we present a retrospective analysis of the basic technique, indications, and outcomes in 286 patients undergoing diagnostic cerebral and spinal angiography in a developing country, Pakistan.

METHODS

A retrospective review of patient demographics, procedural technique and complication rates of 286 consecutive patients undergoing the diagnostic cerebral/spinal angiography procedure at one institution from May 2013 to December 2015 was performed. Neurological, systemic, or local complications occurring within and after 24 h of the procedure were recorded.

RESULTS

Mean age reported for all patients was 49.7 years. Of all the 286 cases, 175 were male (61.2%) and the rest female (111, 38.8%). Cerebral DSA was performed in 279 cases (97.6%), with 7 cases of spinal DSA (2.4%). Subarachnoid hemorrhage was the most common indication for DSA accounting for 88 cases (30.8%), closely followed by stroke (26.6%) and arteriosclerotic vascular disease (23.1%). No intra- or post-procedural neurological complications of any severity were seen in any of the 286 cases. One case of asymptomatic aortic dissection was reported (0.3%) in the entire cohort of patient population.

CONCLUSION

Diagnostic cerebral/spinal digital subtraction angiography was found to be safe in Pakistan, with complication rates at par with and comparable to those reported in the developed world.

Emergency Neurological Life Support: Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a subset of stroke due to bleeding within the parenchyma of the brain. It is potentially lethal, and survival depends on ensuring an adequate airway, reversal of coagulopathy, and proper diagnosis. ICH was chosen as an Emergency Neurological Life Support protocol because intervention within the first critical hour may improve outcome, and it is critical to have site-specific protocols to drive care quickly and efficiently.

Increased risk for complications following diagnostic cerebral angiography in older patients: Trends from the Nationwide Inpatient Sample (1999-2009)

The full utility of diagnostic cerebral angiography, an invasive cerebrovascular imaging technique, is currently debated. Our goal was to determine trends in diagnostic cerebral angiography utilization and associated complications from 1999 through 2009. The National Inpatient Sample (NIS) was used to identify patients who received primary cerebral angiography from 1999-2009 in the United States. We observed trends in discharge volume, total mean charge, and post-procedural complications for this population. Data was based on sample projections and analyzed using univariate and multivariate regression. There were a total of 424,105 discharges indicating primary cerebral angiography nationwide from 1999-2009. The majority of these cases (65%) were in patients older than 55years. Embolic stroke was the most frequent complication, particularly in the oldest age bracket, occurring in 16,304 patients. The risk for complications increased with age (p<0.0001) and with other underlying health conditions. Pulmonary, deep vein thrombosis, and renal associated comorbidities resulted in the greatest risk for developing post-procedural complications. Throughout the study period case volume for cerebral angiography remained constant while total charge per patient increased from $17,365 in 1999 to $45,339 in 2009 (p<0.001). While the overall complication rate for this invasive procedure is relatively low, the potential risk for embolic stroke in older patients is significant. It is worth considering less invasive diagnostic techniques for an older and at risk patient population.

Postoperative imaging for detection of recurrent arteriovenous malformations in children

OBJECT The optimal method for detecting recurrent arteriovenous malformations (AVMs) in children is unknown. An inherent preference exists for MR angiography (MRA) surveillance rather than arteriography. The validity of this strategy is uncertain. METHODS A retrospective chart review was performed on pediatric patients treated for cerebral AVMs at a single institution from 1998 to 2012. Patients with complete obliteration of the AVM nidus after treatment and more than 12 months of follow-up were included in the analysis. Data collection focused on recurrence rates, associated risk factors, and surveillance methods. RESULTS A total of 45 patients with a mean age of 11.7 years (range 0.5-18 years) were treated for AVMs via surgical, endovascular, radiosurgical, or combined approaches. Total AVM obliteration on posttreatment digital subtraction angiography (DSA) was confirmed in 27 patients, of whom the 20 with more than 12 months of follow-up were included in subsequent analysis. The mean follow-up duration in this cohort was 5.75 years (median 5.53 years, range 1.11-10.64 years). Recurrence occurred in 3 of 20 patients (15%). Two recurrences were detected by surveillance DSA and 1 at the time of rehemorrhage. No recurrences were detected by MRA. Median time to recurrence was 33.6 months (range 19-71 months). Two patients (10%) underwent follow-up DSA, 5 (25%) had DSA and MRI/MRA, 9 (45%) had MRI/MRA only, 1 (5%) had CT angiography only, and 3 (15%) had no imaging within the first 3 years of follow-up. After 5 years posttreatment, 2 patients (10%) were followed with MRI/MRA only, 2 (10%) with DSA only, and 10 (50%) with continued DSA and MRI/MRA. CONCLUSIONS AVM recurrence in children occurred at a median of 33.6 months, when MRA was more commonly used for surveillance, but failed to detect any recurrences. A recurrence rate of 15% may be an underestimate given the reliance on surveillance MRA over angiography. A new surveillance strategy is proposed, taking into account exposure to diagnostic radiation and the potential for catastrophic rehemorrhage.

Rule of 5: angiographic diameters of cervicocerebral arteries in children and compatibility with adult neurointerventional devices

Background and purpose

The safety of using adult-sized neuroendovascular devices in the smaller pediatric vasculature is not known. In this study we measure vessel diameters in the cervical and cranial circulation in children to characterize when adult-approved devices might be compatible in children.

Methods

For 54 children without vasculopathy (mean age 9.5±4.9 years (range 0.02–17.8), 20F/34M) undergoing catheter angiography, the diameters of the large vessels in the cervical and cranial circulation (10 locations, 611 total measurements) were assessed by three radiologists. Mean±SD diameter was calculated for the following age groups: 0–6 months, 1, 2, 3, 4, 5–9, 10–14, and 15–18 years. To compare with adult sizes, each vessel measurement was normalized to the respective region mean diameter in the oldest age group (15–18 years). Normalized measurements were compared with age and fitted to a segmented regression.

Results

Vessel diameters increased rapidly from 0 to 5 years of age (slope=0.069/year) but changed minimally beyond that (slope=0.005/year) (R2=0.2). The regression model calculated that, at 5 years of age, vessels would be 94% of the diameter of the oldest age group (compared with 59% at birth). In addition, most vessels in children under 5, while smaller, were still potentially large enough to be compatible with many adult devices.

Conclusions

The growth curve of the cervicocerebral vasculature displays rapid growth until age 5, at which point most children's vessels are nearly adult size. By age 5, most neuroendovascular devices are size-compatible, including thrombectomy devices for stroke. Under 5 years of age, some devices might still be compatible.

Safety of neuroangiography and embolization in children: complication analysis of 697 consecutive procedures in 394 patients

OBJECT

The safe treatment of children using catheter-based angiography and embolization poses unique challenges because of the technical factors regarding the size and fragility of access and target vessels, as well as unique pediatric cerebrovascular pathologies. The complication rates for neurointerventional procedures in children have not been established.

METHODS

The records of a consecutive cohort of pediatric patients who underwent neuroangiography and/or embolization between 2007 and 2013 were reviewed retrospectively to identify both intraprocedural and postprocedural complications. Demographic and clinical risk factors were analyzed with a multivariate logistic regression model.

RESULTS

The 697 consecutive procedures consisted of 429 diagnostic angiograms and 268 embolizations (mean age of patients 11.1 years; range 4 days to 18 years; 217 females). There were 130 intracranial, 122 extracranial, and 16 spinal embolizations. Pathologies included 28 intracranial arteriovenous malformations (AVMs), 12 spinal AVMs, 19 aneurysms, 29 vein of Galen malformations, 29 dural arteriovenous fistulas, 96 extracranial AVMs, 39 tumors, 3 strokes, and 13 others. Overall, 2 intraprocedural and 1 postprocedural complication (0.7%) occurred in the diagnostic group, all of which were nonneurological events. In the embolization group, 7 intraprocedural and 11 postprocedural complications (6.7%) were observed. Of these complications, 15 were nonneurological events (5.6%), 1 was a short-term neurological event (0.4%), and 2 were long-term neurological events (0.7%).

CONCLUSIONS

Neither the technical challenges posed by children's access and target vessels nor the unique neuro-vascular pathologies seen in children need result in an elevated morbidity rate related to neuroangiography and embolization. At a dedicated high-volume center, the complication rates may be lower than those for comparable procedures performed in adults.

A retrospective analysis of severe intraoperative respiratory compliance changes during ophthalmic arterial chemosurgery for retinoblastoma

BACKGROUND AND OBJECTIVES

Ophthalmic arterial chemosurgery for retinoblastoma has been associated with intraoperative decreases in respiratory compliance. Through the analysis of data from computerized records, we objectively defined severe respiratory compliance events and correlated them with demographic and clinical information in patients undergoing this procedure.

METHODS

Data were collected from ophthalmic arterial chemosurgery cases from 2006 to 2013. Intraoperative PIP, PEEP, TV, SpO2 , and EtCO2 were analyzed. Compliance changes, desaturations, decreases in EtCO2 , and clinical outcomes were assessed.

RESULTS

Respiratory compliance decreases with a bimodal distribution. Severe events were defined as exhibiting a minimum compliance decrease of 40%. Seventy-eight of 122 children (64%) experienced a severe compliance event during at least one treatment, and it occurred in 137/468 cases (29%). A subset of 94 children had complete or at least the first three records. The incidence of a severe respiratory compliance event in this subgroup was 17/94 (18%) on the first and 84/261 (32%) on subsequent procedures. The probability of developing a severe respiratory compliance event on a subsequent procedure was 0.40 if the child developed it on the first procedure, 0.30 if he did not; this difference was not significant. The incidence of desaturation below 90% with severe respiratory compliance events was 0.20; the incidence of a 30% drop in EtCO2 was 0.34. No morbidity, no extended recovery, and no admissions were associated with intraoperative severe respiratory compliance events. We found no correlation between history, age, sex, weight or allergies, and intraoperative severe respiratory compliance events.

CONCLUSIONS

Here, most patients experienced a severe respiratory compliance event during at least one of their procedures. Overall incidence was 29% and was more likely on subsequent procedures. A severe respiratory compliance event at the initial procedure was poorly predictive of its occurrence on subsequent procedures. No morbidity was associated with intraoperative severe respiratory compliance events.