Endovascular management of arteriovenous malformations and other intracranial arteriovenous shunts in neonates, infants, and children

Purpose

We discuss the management of cerebral arteriovenous shunts in neonates, infants, and children, with emphasis on our experience with pediatric cerebral arteriovenous malformations (AVMs). The management of vein of Galen malformations is discussed in a separate chapter.

Methods

An all-inclusive retrospective chart review of the endovascular surgery operative record database at the Hyman Newman Institute for Neurology and Neurosurgery at Roosevelt Hospital in NYC was conducted. All consecutive pediatric patients (newborn to 18 years of age) with intracranial arteriovenous shunts who presented from January 1, 2004 to June 16, 2009 were included.

Results

A total of 151 consecutive pediatric patients with intracranial arteriovenous shunts were evaluated from the period of January 1, 2004 to June 16, 2009. This included 56 patients with vein of Galen malformations, 48 cerebral AVMs, 11 patients with pial arteriovenous fistulae, six patients with dural arteriovenous malformations, and 30 patients with mixed intracranial vascular malformations. Forty-four patients underwent a total of 163 endovascular embolizations. The complications rate for endovascular embolizations was 6.7% (11 in 163), 5.5% with temporary complications and 1.2% with permanent complications. The mortality rate for the group of patients (excluding patients with vein of Galen malformations) that underwent endovascular embolizations was 0.0%.

Conclusions

Careful clinical observation and timely intervention are important in the management of pediatric patients with intracranial arteriovenous shunts. Trans-arterial endovascular embolization with liquid embolic agents is the treatment of choice for safe stabilization and/or improvement of symptoms in the group of pediatric patients with intracranial arteriovenous malformations.     

Safety and efficacy using a detachable tip microcatheter in the embolization of pediatric arteriovenous malformations

Purpose

The treatment of deep-seeded pediatric brain arteriovenous malformations (AVMs) remains a challenging task. We describe our experience using a new detachable tip microcatheter in the embolization of brain arteriovenous malformations, pial arteriovenous fistulas, and vein of Galen malformations. We describe the safety and efficacy using a new detachable tip microcatheter in the treatment of pediatric deep brain arteriovenous malformations, pial malformations, and vein of Galen malformations.

Methods

During a period of 9 months from March 2013 through January 2014, 11 pediatric patients in 14 procedures with 27 total injections were selected for treatment with a detachable tip under Food and Drug Administration (FDA) compassionate use exemption and were admitted to our department for treatment of their brain AVM using a liquid embolic agent and a detachable tip microcatheter. The ages of the patients ranged from 3 months to 18 years old.

Results

Of the 27 total injections done, the tip detached in seven cases. For the 16 n-BCA injections, the tip detached six times (37.5 %), and for the 11 Onyx injections, the tip detached one time (9 %). There were no cases of premature microcatheter detachment during normal vessel navigation.

Conclusions

The introduction of these detachable tip microcatheters allows for a safe and relaxed injection that permits a true circumferential occlusion, and may further permit filling a larger amount of angioarchitecture without the risk of distal migration, or vessel damage during the usual rapid removal of non detachable micocatheters.     

Reversible Obstructive Hydrocephalus from Hypertensive Encephalopathy

Background

Diffuse edema involving the posterior fossa may be seen with hypertensive encephalopathy and has rarely been reported to cause hydrocephalus. We present three such cases and review the literature to better delineate this uniquely reversible syndrome.

Methods

Case reports and review of literature.

Results

Three patients with hypertensive encephalopathy presented to our institutions with clinical and radiographic features of obstructive hydrocephalus associated with brainstem and cerebellar edema. This required transient external drainage of cerebrospinal fluid (CSF) in two of the three patients. However, with recognition of this unusual syndrome and aggressive management of elevated blood pressure, both edema and hydrocephalus resolved. All patients made complete recoveries and did not require permanent CSF shunting. A review of the literature yielded 15 additional case reports describing reversible obstructive hydrocephalus related to hypertensive encephalopathy. All had mean arterial pressures above 130 mmHg and presented primarily with altered mental status. While half required ventriculostomy, only one required shunting. Excluding a patient who died from sepsis, all recovered neurologically once blood pressure was controlled.

Conclusion

It is imperative to recognize such cases where hypertension causes edema within the posterior fossa resulting in secondary hydrocephalus. Focusing management on lowering blood pressure avoids unnecessary or prolonged CSF diversion.     

Successful Management of Refractory Intracranial Hypertension from Acute Hyperammonemic Encephalopathy in a Woman with Ornithine Transcarbamylase Deficiency

Background

Ornithine transcarbamylase deficiency (OTCD) is the most common of the urea cycle disorders and results in an accumulation of ammonia and its metabolites. Excess ammonia in the brain is metabolized to glutamine, which increases intracellular osmolarity and contributes to cytotoxic edema.

Methods

We report a case of a woman heterozygous for OTCD who developed acute hyperammonemic encephalopathy and increased intracranial pressure (ICP).

Results

Despite hemodialysis, protein restriction, and administration of pharmacologic nitrogen scavengers, she developed progressive cerebral edema and increased ICP that was refractory to maximal medical management. She underwent a bifrontal decompressive craniectomy resulting in resolution of her intracranial hypertension.

Conclusion

Aggressive multimodality management of the patient coupled with bifrontal decompressive hemicraniectomy was a life-saving measure, offering the patient a reasonable outcome. At 6 month follow-up she had moderate disability on the Glasgow Outcome Score associated with cognitive difficulties.     

Macroglossia Associated with Brainstem Injury

Background

Macroglossia has been reported in patients undergoing posterior fossa neurosurgical procedures and is thought to be as a result of venous engorgement from intubation or mechanical positioning during these prolonged procedures.

Methods

We report three patients who developed macroglossia and dysautonomia of central neurogenic origin following brainstem injury.

Results

The three patients developed macroglossia and dysautonomia with wide hemodynamic fluctuations in the setting of posterior fossa injury of the lower brainstem structures, necessitating tracheostomy placement. Macroglossia was managed with dexamethasone and there was complete resolution of dysautonomia while treated with beta-blockers and gabapentin.

Conclusions

Neurointensivists should be aware of macroglossia with dysautonomia complicating brainstem injury, which may have perilous consequences in the setting of cerebral edema or intracranial hypertension.     

Pediatric intracranial arachnoid cysts: comparative effectiveness of surgical treatment options

Purpose

A variety of surgical approaches for the treatment of pediatric intracranial arachnoid cysts exist. In an effort to identify the optimal surgical treatment for this disorder, we developed a decision analytic model to evaluate outcomes of four surgical approaches in children. These included open craniotomy for cyst excision, open craniotomy for cyst fenestration, endoscopic cyst fenestration, and cystoperitoneal shunting.

Methods

Pooled data were used to create evidence tables, from which we calculated incidence, relative risks, and summary outcomes in quality-adjusted life years (QALYs) for the four surgical treatments. Our study incorporated data up to 5 years postsurgery.

Results

We analyzed 1,324 cases from 36 case series. There were no significant differences in outcome among the four surgical strategies. The QALYs (maximum of 5) for surgical approaches resulted in a range from 4.79 (for open craniotomy and excision) to 4.92 (for endoscopic fenestration).

Conclusions

Overall quality of life is comparable between patients undergoing open craniotomy for cyst excision or fenestration, endoscopic fenestration, and cystoperitoneal shunting up to 5 years after surgery. While each approach offers unique advantages and disadvantages, an individualized treatment strategy should be employed in the setting of surgical outcome equipoise.     

De novo multiple dural arteriovenous fistulas and arteriovenous malformation after embolization of cerebral arteriovenous fistula: case report

Background

A cerebral arteriovenous fistula is a rare neurovascular abnormality. It is very scarce when presenting with other cerebral arteriovenous malformations after embolization.

Method

We reported a case primarily presenting with cerebral arteriovenous fistula. When the fistula was embolized completely, de novo multiple dural arteriovenous fistulas and a small arteriovenous malformation occurred due to the hemodynamic change after the embolization. Embolization of parts of the fistulas for the second time led to an untreatable malformation which became curable. At the third time, the remaining fistula was cured.

Results

The mechanism of the dural arteriovenous fistula and treatment strategy were discussed.

Conclusion

Venous hypertension is the main factor causing a dural arteriovenous fistula. Embolization of the fistulas step by step is recommended.     

A Precision Medicine Approach to Cerebral Edema and Intracranial Hypertension after Severe Traumatic Brain Injury: Quo Vadis?

Purpose of Review

Standard clinical protocols for treating cerebral edema and intracranial hypertension after severe TBI have remained remarkably similar over decades. Cerebral edema and intracranial hypertension are treated interchangeably when in fact intracranial pressure (ICP) is a proxy for cerebral edema but also other processes such as extent of mass lesions, hydrocephalus, or cerebral blood volume. A complex interplay of multiple molecular mechanisms results in cerebral edema after severe TBI, and these are not measured or targeted by current clinically available tools. Addressing these underpinnings may be key to preventing or treating cerebral edema and improving outcome after severe TBI.

Recent Findings

This review begins by outlining basic principles underlying the relationship between edema and ICP including the Monro-Kellie doctrine and concepts of intracranial compliance/elastance. There is a subsequent brief discussion of current guidelines for ICP monitoring/management. We then focus most of the review on an evolving precision medicine approach towards cerebral edema and intracranial hypertension after TBI. Personalization of invasive neuromonitoring parameters including ICP waveform analysis, pulse amplitude, pressure reactivity, and longitudinal trajectories are presented. This is followed by a discussion of cerebral edema subtypes (continuum of ionic/cytotoxic/vasogenic edema and progressive secondary hemorrhage). Mechanisms of potential molecular contributors to cerebral edema after TBI are reviewed. For each target, we present findings from preclinical models, and evaluate their clinical utility as biomarkers and therapeutic targets for cerebral edema reduction. This selection represents promising candidates with evidence from different research groups, overlap/inter-relatedness with other pathways, and clinical/translational potential.

Summary

We outline an evolving precision medicine and translational approach towards cerebral edema and intracranial hypertension after severe TBI.

     

Successful Management of Severe Neuroinvasive Eastern Equine Encephalitis

Background

Eastern Equine Encephalitis (EEE) virus is an arbovirus that mostly causes asymptomatic infection in humans; however, some people can develop a neuroinvasive infection associated with a high mortality.

Methods

We present a case of a patient with severe neuroinvasive EEE.

Results

A 21-year-old man initially presented with headache, fever, and vomiting and was found to have a neutrophilic pleocytosis in his cerebrospinal fluid. He eventually was diagnosed with EEE, treated with high-dose methylprednisolone and intravenous immunoglobulin. His course in the NeuroIntensive Care Unit was complicated by cerebral edema and intracranial hypertension, requiring osmotherapy, pentobarbital and placement of an external ventricular device, and subclinical seizures, necessitating multiple anti-epileptic drugs

Conclusions

A multifaceted approach including aggressive management of cerebral edema and ICP as well as treatment with immunomodulating agents and cessation of seizures may prevent brain herniation, secondary neurologic injury and death in patients with EEE. Effective management and treatment in our patient contributed to a dramatic recovery and ultimate good outcome.     

Shunt dependency syndrome after cystoperitoneal shunting of arachnoid cysts

Purpose

The goal of this study was to investigate the mechanisms, diagnosis, and treatment of shunt dependency syndrome in patients with temporal lobe arachnoid cysts who were initially treated with cystoperitoneal (CP) shunting.

Methods

Thirteen patients with temporal lobe arachnoid cysts who had initially been treated with CP shunt placement and had developed shunt dependency syndrome were treated by the senior author at Tiantan Hospital between April 2010 and January 2012. The clinical manifestations, neuroimaging findings, intracranial pressure (ICP) data, treatment methods, and therapeutic results were reviewed retrospectively.

Results

The study included ten males and three females. The mean age at the time of development of shunt dependency syndrome was 12.3 years (range 5.5–24 years). In most patients, neuroimaging findings showed a collapsed cyst (the cyst appeared almost unchanged in only one patient) and normal or small ventricles (only one patient had enlarged ventricles). Three patients underwent simple replacement of the shunt, four underwent ventriculoperitoneal shunt placement, and the other six underwent lumboperitoneal shunt placement. All patients experienced resolution of their symptoms postoperatively. The mean duration of follow-up was 20 months.

Conclusions

Shunt dependency syndrome is a rare but serious complication of shunting an arachnoid cyst. This condition is similar to the slit ventricle syndrome, but also has some differences. ICP monitoring may confirm the diagnosis when there are no significant radiological findings. Achievement of a shunt-free state might be the ultimate goal for all shunted patients.     

Refractory Intracranial Hypertension in Posterior Reversible Encephalopathy Syndrome

Introduction

Posterior reversible encephalopathy syndrome (PRES) is a largely reversible disease with long-term favorable outcome. A minority of patients, however, may develop progressive cerebral edema and ischemia resulting in severe disability or death. We report a case of severe intracranial hypertension associated with PRES that was successfully treated according to intracranial pressure (ICP)- and cerebral perfusion pressure (CPP)-driven therapy.

Methods

Case report.

Results

A 42-year-old woman underwent bilateral lung transplantation for severe bronchiectasis. Her immunosuppressive regimen consisted of azathioprine, prednisone, and tacrolimus. She acutely developed an aggressive form of PRES that rapidly resulted in severe refractory intracranial hypertension despite discontinuation of potentially causative medications and adequate supportive therapy. Accordingly, second-tier therapies, including barbiturate infusion, were instituted and immunosuppression was switched to anti-thymocyte globulin followed by mycophenolate mofetil. Within 10 h of barbiturate administration, ICP dropped to 20 mmHg. Thiopental was administered for two days and then rapidly tapered because of severe urosepsis. Six months after discharge from the intensive care unit the patient returned to near-normal life, her only complaint being short-term amnesia.

Conclusions

The decision to undertake ICP monitoring in medical conditions in which no clear recommendations exist greatly relies on physicians’ judgment. This case suggests that ICP monitoring may be considered in the setting of acute PRES among selected patients, when severe intracranial hypertension is suspected, provided that a multidisciplinary team of neurocritical care specialists is readily available.     

A case report of a pediatric traumatic aneurysm with arteriovenous (A-V) fistula CASE-BASED UPDATE

Background

Traumatic intracranial aneurysms (TICAs) are rare, representing less than 5 % of all intracranial aneurysms. Most TICAs are located within the anterior circulation, and less than 10 % of TICAs occur in the posterior circulation. Histopathologically, most TICAs are false aneurysms and have a high risk of rupture or re-bleeding. When they are discovered, careful observation or treatment may be required. Once they are enlarged, they have a high risk of rupture, and immediate treatment is essential.

Case report

For the first time in the literature, we report a rare case of an 8-year-old boy with a TICA in anterior inferior cerebellar artery (AICA) and arteriovenous (A-V) fistula after severe head trauma. Trapping of AICA and resection of the aneurysm was performed. Postoperatively, he has peripheral facial palsy but is otherwise neurologically normal.

Conclusion

Surgical treatment for traumatic aneurysms is challenging because most of TICAs are histopathologically pseudoaneurysms. It may be technically difficult to perform direct surgery of aneurysms especially located in the posterior circulation, but when the treatment is successful, the outcome was favorable.     

A spectrum of intracranial vascular high-flow arteriovenous shunts in RASA1 mutations

Purpose and background

We describe three paediatric cases with different intracranial fast-flow shunts presenting early in life, all with capillary malformation–arteriovenous malformation syndrome and RASA1 verified mutations. Intracranial arteriovenous fast-flow shunts are rare vascular malformations typically presenting early in life and have been associated with cutaneous capillary malformations, characterized as capillary malformation–arteriovenous malformation syndrome. Heterozygous RASA1 gene mutations have been found to be disease causing with high penetrance for the typical cutaneous findings, but only some individuals with the syndrome have intracranial lesions.

Cases

One infant presented with a vein of Galen malformation responsible for hydrodynamic disorders, one neonate suffered from severe cardiac insufficiency related to a superior sagittal sinus dural malformation with high-flow fistulas, and one baby was treated at infant age of a choroidal arteriovenous fistula discovered antenatally.

Results and conclusions

We report the follow-up of these three cases with RASA1 gene mutation and comment on the possible role of evaluation for vascular lesions and capillary malformation–arteriovenous malformation syndrome in patients and their families, with intracranial fast-flow shunts.

     

Posterior Reversible Leukoencephalopathy Syndrome Presenting with Global Cerebral Edema and Herniation

Background

We report a case of global cerebral edema and herniation due to Posterior Reversible Leukoencephalopathy Syndrome (PRES).

Methods

Case report.

Results

A 37-year-old healthy female developed persistent severe occipital headache, and after 1 month of persistent headache, developed an episode of loss of consciousness.  CT brain showed diffuse cerebral edema and effacement of the sulci and basal cisterns. Her initial neurological examination was nonfocal but with severe headache. Overnight, she acutely became unresponsive with fixed dilated pupils, tachycardia, and hypertension.  She was intubated and treated with hypertonic saline and mannitol with improvement in her clinical status. Intracranial Pressure (ICP) monitor showed elevated ICPs to 37 mmHg which responded to mannitol. MRI brain showed diffuse vasogenic edema predominantly in the white matter without enhancement. Cerebral angiogram was unremarkable. Cerebrospinal fluid including infectious work-up was negative.  With supportive care, her mental status improved. On her 3 month follow-up visit, she was asymptomatic and had returned to work. Repeat MRI brain at 3 months showed persistent white matter changes that subsequently resolved at 9 months. 

Conclusions

Although PRES is typically considered to have a benign clinical course, clinician should be aware that severe cases can present with global cerebral edema and associated complications including intracranial hypertension and herniation.     

A Neurological Complication of a Uterine Fibroid

Background

Uterine leiomyoma (or fibroid) can be associated with secondary polycythemia and venous thrombosis, but there has been no report of intracranial venous thrombosis associated with leiomyoma.

Methods

We describe a case report of a cerebral venous thrombosis associated with erythrocytosis and a uterine fibroid in a non-smoking female with no history of malignancy or hormone use. The hemoglobin and erythropoietin normalized after removal of her uterine fibroid.

Results

MRI/MRV of this 60-year-old cephalalgic female revealed extensive thrombus throughout the sagittal sinus and right transverse sinus. CT of the abdomen revealed a 16 × 13 × 12 cm solid mass arising for the uterus consistent with a uterine fibroid. PET scan was negative for malignancy. Hemoglobin on admission was 18.4 g/dl. Erythropoietin was 16.6 mIU/ml. One month after hysterectomy, her hemoglobin was 12.6 g/dl and her erythropoietin was 4.7 mIU/ml.

Conclusions

Cerebral vein thrombosis is a potential complication of uterine fibroids with erythrocytosis.     

PAI-1-Derived Peptide EEIIMD Prevents Hypoxia/Ischemia-Induced Aggravation of Endothelin- and Thromboxane-Induced Cerebrovasoconstriction

Background

Babies are frequently exposed to cerebral hypoxia and ischemia (H/I) during the perinatal period as a result of stroke, problems with delivery or post delivery respiratory management. The sole FDA approved treatment for acute stroke is tissue-type plasminogen activator (tPA). Endogenous tPA is upregulated and potentiates impairment of pial artery dilation in response to hypotension after H/I in pigs. Mitogen-activated protein kinase (MAPK), a family of at least 3 kinases, ERK, p38 and JNK, is also upregulated after H/I, with ERK contributing to impaired vasodilation. This study examined the hypothesis that H/I aggravates the vascular response to two important procontractile mediators released during CNS ischemia, endothelin-1 (ET-1) and thromboxane, which is further enhanced by tPA and ERK MAPK.

Methods

Cerebral hypoxia (pO₂ 35 mmHg for 10 min via inhalation of N₂) followed immediately by ischemia (global intracranial pressure elevation for 20 min) was produced in chloralose anesthetized piglets equipped with a closed cranial window.

Results

H/I aggravated pial artery vasconstriction induced by ET-1 and the thromboxane mimetic U 46619. Potentiated vasoconstrictor responses were blocked by EEIIMD, an inhibitor of tPA’s signaling and vascular activities, but unchanged by its inactive analogue EEIIMR. The cerebrospinal fluid concentration of ERK MAPK determined by ELISA was increased by H/I, potentiated by tPA, but blocked by EEIIMD. The ERK MAPK antagonist U 0126 blocked H/I augmented enhancement of ET-1 and U 46619 vasoconstriction.

Conclusions

These data indicate that H/I aggravates ET-1 and thromboxane mediated cerebral vasoconstriction by upregulating endogenous tPA and ERK MAPK.     

Continuous Electroencephalography (cEEG) Changes Precede Clinical Changes in a Case of Progressive Cerebral Edema

Background

Continuous electroencephalogram (cEEG) is tightly linked to cerebral metabolism and is sensitive to cerebral ischemia and hypoxia. The severity of cerebral ischemia can be seen on cEEG as changes in morphology, amplitude, or frequency, and cEEG may detect neuronal dysfunction at a reversible stage.

Methods

Case report and imaging.

Results

We present a case of focal cerebral edema with changes seen on cEEG 24 h before clinical signs of increased intracranial pressure. cEEG showed developing asymmetry in the left hemisphere followed by burst suppression. The right hemisphere showed similar progression to burst suppression. Complete suppression of both hemispheres was noted 6 h before clinical signs of herniation. Computed tomography (CT) head confirmed a large left parietal intracerebral hematoma with mass effect.

Conclusions

cEEG has applications in monitoring cerebral dysfunction in addition to detecting seizure activity in the intensive care unit. It may serve a vital role in multi-modality monitoring for early recognition of neurological complications from brain injuries that may not be noticed clinically, which is paramount to early intervention.     

The intracranial bridging veins: a comprehensive review of their history, anatomy, histology, pathology, and neurosurgical implications

Introduction

The intracranial bridging veins are pathways crucial for venous drainage of the brain. They are not only involved in pathological conditions but also serve as important landmarks within neurological surgery.

Methods

The medical literature on bridging veins was reviewed in regard to their historical aspects, embryology, histology, anatomy, and surgery.

Conclusion

Knowledge on the intracranial bridging veins and their dynamics has evolved over time and is of great significance to the neurosurgeon.     

Clinical features and endovascular treatment of intracranial arteriovenous malformations in pediatric patients

Purpose

The purpose of this study was to characterize clinical features and evaluate the clinical outcome of endovascular embolization treatment intracranial arteriovenous malformations in pediatric patients.

Methods

A cohort of children (age?≤?18 years) with arteriovenous malformations (AVMs) from 2000 to 2012 was included. Predictors studied included patient gender, age, and angioarchitectural features, including AVM location, nidus morphology and size, venous drainage, and associated aneurysms. Treatment method, complications and outcomes were recorded. The features of AVMs were evaluated before the treatment.

Results

One hundred twenty-seven children (77 males, mean age 13.2 years) were included; 90/127 (70.9 %) children were presented with hemorrhage. AVM size and deep venous drainage were independently associated with hemorrhage; 66/127 patients (52 %) treated with endovascular embolization. Complete obliteration at the end of all endovascular procedures was achieved in 14/66 patients (21.2 %), with an average of 78 % (range, 20–100 %) volume reduction. A mean of 2.9 (range, 1–9) feeding pedicles was embolized per patient. Overall, nine complications occurred in a total of 123 procedures (7.3 %). There was no procedure-related death in this study population. There was no significant difference between patients with and without complications in terms of AVM grade, demographic characteristics, or embolization features.

Conclusions

AVM size and deep venous drainage were independently associated with hemorrhage in pediatric patients. Endovascular procedure is feasible and safe for pediatric AVMs, and complete embolization can be achieved in small AVMs, while large AVMs can be adequately reduced in size for additional microsurgery or stereotactic radiosurgery.