Pregnancy and the risk of hemorrhage from cerebral arteriovenous malformations

Management of Brain Arteriovenous Malformations: A Review

Brain arteriovenous malformations (bAVM) are vascular malformations of the brain affecting all ages. The optimum management strategy is essentially devoid of high-quality evidence and is highly nuanced and embedded in local customs. This study summarizes the frequently employed management strategies, drawing conclusions on the utility of each method of treatment and delving into controversies surrounding them. A literature search on PubMed and Medline was done on January 3^rd, 2022. 11,767 articles were found, and abstracts were reviewed. Full-text review of 153 articles led to chapters from three books and 71 articles incorporated into a summative discussion. Spetzler-Ponce (S-P) Class A patients may be offered surgery if they are good surgical candidates and have a good number of high-quality years of life left. The exception is diffuse Spetzler-Martin (S-M) grade 2 in a patient older than 40 years: radiosurgery for unruptured and embolization for ruptured. S-P Class B may be offered surgery if a compact nidus or if younger than 40 years. If diffuse or age greater than 40, radiosurgery may be preferred if the Pollock-Flickinger score is less than 2.5. For the remainder of S-P Class B, conservative management may be preferred. S-P Class C is generally not treated unless young or those patients with poorly controlled seizures affecting their quality of life are willing to risk permanent neurological deficits. While the quality of studies is generally high, the level of evidence is concerning with only one randomized controlled trial (RCT). Most research output hails from high-income countries, i.e., perhaps not universally applicable to all settings owing to possible genetic, environmental, and resource differences. More research is needed: large volume studies in the pregnant population, validation of scoring systems in pediatric age groups, clinical trials focused on combination multi-staged treatment modalities, and studies originating from the developing world.

Stroke in Pregnancy: A Multidisciplinary Approach

Pregnancy confers a substantially increased risk of stroke, especially during the third trimester and until 6 weeks postpartum. Hypertensive disorders of pregnancy and gestational hypercoagulability are important contributors to obstetric stroke. Preeclampsia and eclampsia confer risk for future cardiovascular disease. Hemorrhagic stroke is the most common type of obstetric stroke. Ischemic stroke can result from cardiomyopathy, paradoxical embolism, posterior reversible encephalopathy, reversible cerebral vasoconstriction syndrome, and dissections. Cerebral venous sinus thrombosis is a frequent complication of pregnancy.

Management of a ruptured and unruptured pial arteriovenous fistula during and after pregnancy

We present the case of a 16-week pregnant 19-year-old female who presented with hemiplegia due to a ruptured right frontal pial arteriovenous fistula (PAVF). She was also found to have an unruptured right temporal PAVF and a family history of brain hemorrhage. The patient was managed with Onyx embolization of the ruptured fistula, followed by surgical excision and hematoma evacuation. At 35 weeks gestation, she underwent cesarean section to prevent rupture of the second fistula in the setting of peripartum hypervolemia and increasing headaches. The child was delivered healthy. Subsequently, the right temporal AV fistula, supplied by a middle cerebral artery and posterior cerebral artery branch, underwent staged embolization resulting in complete occlusion. The patient recovered to a modified Rankin score of two, with a left foot drop as only persistent significant motor deficit.

Maternal and Fetal Outcomes in Women with Brain Arteriovenous Malformation Rupture during Pregnancy

BACKGROUND

Sporadic brain arteriovenous malformations (BAVM) are a major cause of hemorrhagic stroke in younger persons. Prior studies have reported contradictory results regarding the risk of hemorrhage during pregnancy, and there are no standard guidelines for the management of pregnant women who present with BAVM rupture. The purpose of this study is to describe maternal and fetal outcomes and treatment strategies in patients with BAVM hemorrhage during pregnancy.

METHODS

We performed a retrospective review of the University of California, San Francisco Brain AVM Project database for female patients who were pregnant at the time of BAVM hemorrhage between 2000 and 2017. Clinical and angiographic characteristics at presentation, BAVM treatment, and maternal outcomes using modified Rankin scale (mRS) score at presentation and 2-year follow-up were recorded. Fetal outcomes were abstracted from medical records and maternal reports.

RESULTS

Sixteen patients presented with BAVM hemorrhage during pregnancy, 81% (n = 13) of whom were in their second or third trimester. Three patients (19%) who were in their first trimester terminated or miscarried pregnancy prior to BAVM intervention. Of the remaining 13 patients, 77% (n = 10) received emergent BAVM treatment at time of hemorrhage prior to delivery, and 85% of patients achieved BAVM obliteration and good maternal outcomes (mRS 0-2) at 2-year follow-up. All patients had uncomplicated deliveries (69% cesarean and 23% vaginal) with no reports of postnatal cognitive or developmental delays in infants at 2-year follow-up.

CONCLUSIONS

Our study shows good long-term maternal and fetal outcomes in ruptured BAVM patients presenting during pregnancy, the majority who received BAVM interventional treatment prior to delivery.

Stroke in Pregnancy: A Focused Update

Ischemic stroke (IS) and hemorrhagic stroke (HS) can be devastating complications during pregnancy and the puerperium that are thought to occur in approximately 30 in 100,000 pregnancies. In high-risk groups, such as women with preeclampsia, the incidence of both stroke subtypes, combined, is up to 6-fold higher than in pregnant women without these disorders. IS or HS may present in young women with atypical symptoms including headache, seizure, extremity weakness, dizziness, nausea, behavioral changes, and visual symptoms. Obstetric anesthesiologists who recognize these signs and symptoms of pregnancy-related stroke are well positioned to facilitate timely care. Acute stroke of any type is an emergency that should prompt immediate coordination of care between obstetric anesthesiologists, stroke neurologists, high-risk obstetricians, nurses, and neonatologists. Historically, guidelines have not addressed the unique situation of maternal stroke, and pregnant women have been excluded from the large stroke trials. More recently, several publications and professional societies have highlighted that pregnant women suspected of having IS or HS should be evaluated for the same therapies as nonpregnant women. Vaginal delivery is generally preferred unless there are obstetric indications for cesarean delivery. Neuraxial analgesia and anesthesia are frequently safer than general anesthesia for cesarean delivery in the patient with a recent stroke. Potential exceptions include therapeutic anticoagulation or intracranial hypertension with risk of herniation. General anesthesia may be appropriate when cesarean delivery will be combined with intracranial neurosurgery.

Surgical removal of an arteriovenous malformation in the anterior perforated substance in a pregnant woman

Background:

A tailor-made treatment is often required in arteriovenous malformations (AVMs) depending on the individual situation. In most cases, treatment strategy is usually determined according to the patient's Spetzler–Martin grade. However, in the present case, we were not able to treat the patient following the usual guidelines because of neurological symptoms and pregnancy.

Case Description:

We describe a rare case of a 31-year-old woman in the 15^th week of gestation who presented with an AVM in the anterior perforated substance (APS). She suffered a sudden coma and hemiplegia. A computed tomographic scan showed an enhanced mass and a huge hematoma in the basal ganglia and temporal lobe. The hematoma was successfully evacuated in an endoscopic procedure. Angiography showed that a 25-mm nidus in the APS was fed by the anterior choroidal arteries (AChAs) and the lenticulostriate arteries (LSAs). Therefore, we attempted to remove the nidus because the patient became alert with mild aphasia and hemiparesis 10 days after hemorrhage. The feeding arteries were cut under motor evoked potential (MEP) monitoring, and the nidus was totally resected leaving two of four AChAs and a single artery with several LSAs. The postoperative course was uneventful, and she gave birth to a healthy baby by caesarian delivery 122 days after the hemorrhage with only minor sequelae.

Conclusions:

Surgical strategy with a device-administered anesthesia are suitable for removing large AVMs even in pregnant women and for the successful outcome of their pregnancies. Even after recovering from a coma and hemiplegia, MEP monitoring is effective for removing large AVMs even when located in the APS.

The Impact of Pregnancy on Hemorrhagic Stroke in Young Women

BACKGROUND

Pregnancy is a sex-specific risk factor for causing hemorrhagic stroke (HS) in young adults. Unique physiological characteristics during pregnancy may alter the relative risk for HS in pregnant/postpartum (PP) women compared to HS in other young women. We compared patient characteristics and HS subtypes between young non-pregnant and PP women.

METHODS

We reviewed the medical records of all women 18-45 years old admitted to our center with HS from October 15, 2008 through March 31, 2015, and compared patient characteristics and stroke mechanisms using logistic regression.

RESULTS

Of the 130 young women with HS during the study period, 111 were non-PP women, and 19 PP women. PP women had lower proportions of vascular risk factors such as hypertension, prior stroke, and smoking, and a higher proportion of migraine (36.8 vs. 14.4%, p = 0.01). After adjusting for hypertension, smoking, migraine, prior stroke and prior myocardial infarction, PP women had lower odds of having an underlying vascular lesion (OR 0.14, 95% CI 0.04-0.44, p = 0.0009) and a higher proportion of the reversible cerebral vasoconstriction syndrome (RCVS) as cause of their HS.

CONCLUSIONS

Women with pregnancy-associated HS had fewer cerebrovascular risk factors, lower odds of having -underlying vascular lesions, and higher proportion of -migraine and RCVS compared with similar-aged non--pregnant women. Pregnancy-associated HS appears to represent a unique pathophysiological process, requiring targeted study.

Known and unknown cerebral arteriovenous malformations in pregnancies: haemorrhage risk and influence on obstetric management

Objective The objective of this study was to evaluate the haemorrhage risk of known and unknown cerebral arteriovenous malformations and their obstetric management. Methods A retrospective review was performed and analysed 67 consecutive cases of arteriovenous malformation with pregnancy history. Results Sixty-seven cases of arteriovenous malformation with pregnancy histories were identified. In 14 cases (20.9%) of arteriovenous malformation diagnosed before pregnancy, 11 cases were treated (10 embolisation and one surgery), there was no haemorrhage in 14 pregnancies, 14 healthy babies were delivered by caesarean section in 12 pregnancies (85.7%) and vaginal delivery in two pregnancies (14.3%). In 53 cases (89.1%) of arteriovenous malformation diagnosed during/after pregnancy, there was one (1.6%) case of subarachnoid haemorrhage at 38 weeks' gestation in 64 pregnancies, 64 healthy babies were delivered by caesarean section in 11 pregnancies (17.2%) and vaginal delivery in 53 pregnancies (82.8%). This resulted in 1.6% (95% confidence interval 0-4.6%) haemorrhage rate per pregnancy in unknown arteriovenous malformations. Known arteriovenous malformation gravida was prone to caesarean section; however, vaginal delivery did not increase the haemorrhage risk in unknown arteriovenous malformation gravidas (1.8% vs. 0%, P = 1.000). Conclusion Prior treatment for ruptured arteriovenous malformation could prevent its haemorrhage during pregnancy and the haemorrhage risk of unruptured arteriovenous malformation in pregnancies is low. Although known arteriovenous malformation gravida is prone to caesarean section, vaginal delivery seems not to increase the haemorrhage risk in unknown arteriovenous malformation gravidas.

Management strategies for neoplastic and vascular brain lesions presenting during pregnancy: A series of 29 patients

BACKGROUND

The occurrence of a brain tumor or intracranial vascular lesion during pregnancy is a rare event, but when it happens, it jeopardizes the lives of both the mother and infant. It also creates challenges of a neurosurgical, obstetric, and ethical nature. A multidisciplinary approach should be used for their care.

METHODS

Between 1986 and 2015, 12 pregnant women diagnosed with brain tumors and 17 women with intracranial vascular lesion underwent treatment at the Neurosurgery Department of the Servidores do Estado Hospital and Rede D'Or/São Luis. The Neurosurgery Department teamed up with Obstetrics Anesthesiology Departments in establishing the procedures. The patients' records, surgical descriptions, imaging studies, and histopathological material were reviewed.

RESULTS

Among 12 patients presenting with brain tumors, there were neither operative mortality nor fetal deaths. Among the vascular lesions, aneurysm rupture was responsible for bleeding in 6 instances. Arteriovenous malformation was diagnosed in 7 patients. In this subgroup, the maternal and fetal mortality rates were 11.7% and 23.7%, respectively.

CONCLUSIONS

We can assert that the association between a brain tumor and vascular lesions with pregnancy is a very unusual event, which jeopardizes both the lives of the mother and infant. It remains incompletely characterized due to the rare nature of these potentially devastating events. Knowing the exact mechanism responsible for the interaction of pregnancy and with these lesions will improve the treatment of these patients.

The clinical characteristics and treatment of cerebral AVM in pregnancy

Cerebral arteriovenous malformation (AVM) in pregnancy is a complex situation and there is no agreement on its hemorrhage risk and treatment. Although studies on bleeding risk of cerebral AVMs in pregnancy are very few and there are different results between them, pregnancy will increase the hemorrhagic risk of AVM, and ruptured cerebral AVM in pregnancy should be treated actively. After intracranial hemorrhage, cerebral angiography should be performed for pregnant women shielded correctly. Cerebral angiography could clearly demonstrate the characteristics of cerebral AVM. The results from the literature show that the radiation dose of endovascular and stereotactic radiotherapy for cerebral AVM in pregnancy is below the safety value and is safe. Unruptured AVM in pregnancy, if there is no bleeding factor, such as no coexisting aneurysm, smooth venous drainage, no venous ectasia, or high risk of treatment, should be observed conservatively.

Periventricular Location as a Risk Factor for Hemorrhage and Severe Clinical Presentation in Pediatric Patients with Untreated Brain Arteriovenous Malformations

BACKGROUND AND PURPOSE

The morphologic features of brain arteriovenous malformations differ between children and adults; therefore, our aim was to analyze various features of brain arteriovenous malformations to assess the risk of hemorrhage in children.

MATERIALS AND METHODS

We identified all consecutive children admitted to Beijing Tiantan Hospital for brain arteriovenous malformations between July 2009 and April 2014. The effects of demographic characteristics and brain arteriovenous malformation morphology on hemorrhage presentation, annual bleeding rates, postnatal hemorrhage, and immediate posthemorrhagic neurologic outcomes were studied by using univariate and multivariable regression analyses.

RESULTS

A total of 108 pediatric brain arteriovenous malformation cases were identified, 66 (61.1%) of which presented with hemorrhage. Of these, 69.7% of ruptured brain arteriovenous malformations were in a periventricular location. Periventricular nidus location (OR, 3.443; 95% CI, 1.328-8.926; P = .011) and nidus size (OR, 0.965; 95% CI, 0.941-0.989; P = .005) were independent predictors of hemorrhagic presentation. The annual hemorrhage rates in children with periventricular brain arteriovenous malformations were higher at 6.88% (OR, 1.965; 95% CI, 1.155-3.341; P < .05). The hemorrhage-free survival rates were also lower for children with periventricular brain arteriovenous malformations (log-rank, P = .01). Periventricular location (hazard ratio, 1.917; 95% CI, 1.131-3.250; P = .016) and nidus size (hazard ratio, 0.983; 95% CI, 0.969-0.997; P = .015) were associated with hemorrhage after birth in pediatric brain arteriovenous malformations. An ordinal analysis showed lower immediate posthemorrhage mRS in patients with periventricular brain arteriovenous malformations (OR for greater disability, 2.71; 95% CI, 1.03-7.11; P = .043).

CONCLUSIONS

Small periventricular brain arteriovenous malformations were associated with increased hemorrhage risk in pediatric patients. Cautious follow-up of children with untreated periventricular brain arteriovenous malformations is recommended because of a higher hemorrhage risk and potentially more severe neurologic outcomes.

The clinical characteristics and treatment of cerebral AVM in pregnancy

Cerebral arteriovenous malformation (AVM) in pregnancy is a complex situation and there is no agreement on its hemorrhage risk and treatment. Although studies on bleeding risk of cerebral AVMs in pregnancy are very few, and they provide different results, pregnancy will increase the hemorrhagic risk of AVM and ruptured cerebral AVM in pregnancy should be actively treated. After intracranial hemorrhage, cerebral angiography should be performed for pregnant women shielded correctly. Cerebral angiography could clearly demonstrate the characteristics of cerebral AVM. Results from the literature show that the radiation dose of endovascular and stereotactic radiotherapy for cerebral AVM in pregnancy was below the safety value and was safe. For an unruptured AVM in pregnancy, if there are no bleeding factors, e.g. no coexisting aneurysm, smooth venous drainage, no venous ectasia, or high risk of treatment, then it should be observed conservatively.

Management of brain arteriovenous malformations

OPINION STATEMENT

Arteriovenous malformations (AVMs) pose a risk of morbidity and mortality throughout an affected patient's lifetime. Over the course of a patient's life, the risk of hemorrhage is approximately 1-4 % per year, and after an initial hemorrhage occurs, this risk may be higher. Other causes of morbidity include seizures, headaches, or progressive neurologic deficits. Once an AVM has been discovered, the utility of attempted obliteration or surgical resection compared to the risk of intervention should be entertained. The characteristics of the malformation as well as the patient's overall health status contribute to the decision to intervene on these lesions. For small lesions located in superficial areas without high-risk surgical characteristics (low-grade Spetzler-Martin grades), it is reasonable to consider surgical resection. In lesions that pose high-risk of complications from surgical removal, intra-arterial embolization, radiosurgery, or a combination of the two may be reasonable treatment options. Some AVMs at traditional high surgical risk may be amenable to partial embolization, allowing initially high-risk lesions to become better candidates for surgical resection. In some patients, particularly those who are older or who have multiple medical comorbidities, the risk of intervention as compared to the annual hemorrhage risk may warrant conservative management as opposed to intervention. The overall treatment strategy must be based on patient and AVM characteristics and careful risk-benefit ratio analysis.

Cerebrovascular complications of pregnancy and the postpartum period

Cerebrovascular complications of pregnancy, though uncommon, threaten women with severe morbidity or death, and they are the main causes of major long-term disability associated with pregnancy. In this review, we discuss the epidemiology, pathophysiology, presentation and diagnosis, and management and outcomes of ischemic and hemorrhagic stroke and cerebral venous thrombosis. We also discuss the posterior reversible encephalopathy syndrome, the reversible cerebral vasoconstriction syndrome including postpartum cerebral angiopathy, and their relationship as overlapping manifestations of pre-eclampsia-eclampsia.

Endovascular management of arteriovenous malformations of the brain

Arteriovenous malformations (AVMs) of the brain are rare, complex, vascular lesions that can result in significant morbidity and mortality. Modern treatment of brain AVMs is a multimodality endeavor, requiring a multidisciplinary team with expertise in cerebrovascular neurosurgery, endovascular intervention, and radiation therapy in order to provide all therapeutic options and determine the most appropriate treatment regimen depending on patient characteristics and AVM morphology. Current therapeutic options include microsurgical resection, radiosurgery (focused radiation), and endovascular embolization. Endovascular embolization is primarily used as a preoperative adjuvant before microsurgery or radiosurgery. Palliative embolization has been used successfully to reduce the risk of hemorrhage, alleviate clinical symptoms, and preserve or improve neurological function in inoperable or nonradiosurgical AVMs. Less frequently, embolization is used as 'primary therapy' particularly for smaller, surgically difficult lesions. Current embolic agents used to treat brain AVMs include both solid and liquid agents. Liquid agents including N-butyl cyanoacrylate and Onyx are the most commonly used agents. As newer embolic agents become available and as microcatheter technology improves, the role of endovascular treatment for brain AVMs will likely expand.

Risk of cerebral arteriovenous malformation rupture during pregnancy and puerperium

OBJECTIVE

To determine whether the risk of arteriovenous malformation (AVM) rupture is increased during pregnancy and puerperium.

METHODS

Participants included 979 female patients with intracranial AVM admitted to Beijing Tiantan Hospital between 1960 and 2010. Two neurosurgery residents reviewed medical records for each case. Of them, 393 patients with ruptured AVM between 18 and 40 years of age were used for case-crossover analysis. Number of children born and clinical information during pregnancy and puerperium were retrieved to identify whether AVM rupture occurred during this period.

RESULTS

Of the 979 women, 797 hemorrhages occurred during 25,578 patient-years of follow-up, yielding an annual hemorrhage rate of 3.11%. The annual AVM hemorrhage rate in patients aged 18 to 40 years (n = 579) was 2.78%, lower than the rate in other age groups (odds ratio = 0.75, 95% confidence interval 0.65-0.86, p < 0.05). Of the 393 patients with rupture of AVM aged 18 to 40 years, 12 hemorrhages occurred in 12 patients over 452 pregnancies, yielding a hemorrhage rate of 2.65% per pregnancy or 3.32% per year. Among the remaining 381 patients, 441 hemorrhages occurred during 10,627 patient-years of follow-up, yielding an annual hemorrhage rate of 4.14%. The odds ratio for rupture of AVM during pregnancy and puerperium, compared with the control period, was 0.71 (95% confidence interval 0.61-0.82).

CONCLUSIONS

No increased risk of hemorrhage was found in patients with cerebral AVM during pregnancy and the puerperium. We therefore would not advise against pregnancy in women with intracranial AVM.

Utility of intraoperative fetal heart rate monitoring for cerebral arteriovenous malformation surgery during pregnancy

We report two methods of intraoperative fetal heart rate (FHR) monitoring in cases of cerebral arteriovenous malformation surgery during pregnancy. In one case in her third trimester, cardiotocography was used. In another case in her second trimester, ultrasound sonography was used, with a transesophageal echo probe attached to her lower abdomen. Especially, the transesophageal echo probe was useful because of the advantages of being flexible and easy to attach to the mother's lower abdomen comparing with the usual doppler ultrasound probe. In both cases, the surgery was successfully performed and FHR was monitored safely and stably. The use of intraoperative FHR monitoring provides information about the influence of induced maternal hypotension and unexpected bleeding on fetus during surgery. These monitoring techniques would be especially emphasized in cerebrovascular surgery for the safe management of both mother and fetus.

Headache in pregnancy: a nuisance or a new sense?

Headache is a very commonly encountered symptom in pregnancy and is usually due to primary headache disorders which are benign in nature. It can however be quite debilitating for some women who may need therapeutic treatment of which there are several options safe to use in pregnancy. It is equally important though to recognise that headache may be a sign of serious underlying pathology. This paper aims to provide a clinically useful guidance for differentiation between primary and secondary headaches in pregnancy. The primary headache disorders and their management in pregnancy are explored in depth with brief overviews of the causes for secondary headaches and their further investigation and management.

Intracerebral hemorrhage: a life-threatening complication of hypertension during pregnancy

Intracerebral hemorrhage (ICH) is an infrequent but severe complication in pregnant women with hypertension. The authors describe a patient with chronic hypertension who developed superimposed preeclampsia and spontaneous ICH during the thirty-fifth week of pregnancy. ICH was diagnosed by computed tomographic scan. She underwent successful emergent cesarean section and neurosurgical decompression of the ICH. Both intraoperative surveillance and postoperative magnetic resonance angiographic examination of the cerebral vessels failed to identify an aneurysm or arteriovenous malformation. The authors discuss the diagnosis and management in this case and review the literature regarding this challenging complication of pregnancy and preeclampsia. Controversies regarding treatment of hypertension during pregnancy are discussed in light of the impact on the management of this patient.

Cerebrovascular Disease in Pregnancy

Stroke during pregnancy is a special category of stroke in young women. Although the absolute risk is small, there are diverse causes, including those inherent to the pregnant state, that may have a significant impact on maternal and fetal outcome. Severe pre-eclampsia and eclampsia are commonly associated with ischemic and hemorrhagic stroke, but must not be presumed the sole cause of stroke in pregnant women. Magnesium sulfate is the treatment of choice to prevent eclampsia. Randomized clinical trials in pregnant women are not available to provide guidance for the treatment of ischemic and hemorrhagic stroke in pregnant women. Various antithrombotic agents may be safely used during specific stages of pregnancy for treatment and prevention of ischemic stroke, with low-dose aspirin, unfractionated heparin, and low molecular weight heparin the preferred agents. Low molecular weight heparin may be safer than unfractionated heparin. Treatment of parenchymatous intracerebral hemorrhage and subarachnoid hemorrhage during pregnancy and the puerperium must be individualized. Aneurysms may be treated with neurosurgical clipping or endovascular coiling, depending on neurosurgical considerations. Cesarean or vaginal delivery may be used depending on the timing of delivery, adequacy of aneurysm occlusion, and risk to mother and fetus. Arteriovenous malformations are best treated in a multimodal fashion at a specialized treatment center.