Limitations of fetal ultrasonography and magnetic resonance imaging in prenatal diagnosis of congenital cerebral arteriovenous malformations with hemorrhagic onset

Hemorrhage and necrosis of the liver caused by hepatic arteriovenous malformations in a fetus: A case report

RATIONALE

Hepatic arteriovenous malformations (HAVMs) are a rare disorder reported in association with hereditary hemorrhagic telangiectasia (HHT), known as Rendu-Osler-Weber syndrome. HAVMs are usually detected in adulthood.

PATIENT CONCERNS

A 29-year-old pregnant woman underwent a routine prenatal examination at 37 weeks of pregnancy.

DIAGNOSIS AND INTERVENTIONS

There were fetal liver anomalies detected by prenatal ultrasonography and were managed. Furthermore, a hepatic mass was detected and was subsequently analyzed by fetal magnetic resonance imaging. There were no typical imaging findings in this case which was once misdiagnosed as a hepatoblastoma.

OUTCOMES

Considering the massive hepatic lesion, labor induction was performed on a pregnant woman to avoid adverse maternal and fetal outcomes. Histopathological examination confirmed the diagnosis of HAVMs. Lesions detected by imaging were determined to be hemorrhagic and necrotic.

LESSONS

Prenatal hepatic hemorrhage and necrosis due to an arteriovenous malformation are rare. The authors describe their observations and results.

A novel method to determine the natural course of unruptured brain arteriovenous malformations without the need for follow-up information

OBJECTIVEThere is a strong clinical need to accurately determine the average annual hemorrhage risk in unruptured brain arteriovenous malformations (AVMs). This need motivated the present initiative to use data from a uniquely large patient population and design a novel methodology to achieve a risk determination with unprecedented accuracy. The authors also aimed to determine the impact of sex, pregnancy, AVM volume, and location on the risk for AVM rupture.METHODSThe present study does not consider any specific management of the AVMs, but only uses the age distribution for the first hemorrhage, the shape of which becomes universal for a sufficiently large set of patients. For this purpose, the authors collected observations, including age at first hemorrhage and AVM size and location, in 3425 patients. The average annual risk for hemorrhage could then be determined from the simple relation that the number of patients with their first hemorrhage at a specific age equals the risk for hemorrhage times the number of patients at risk at that age. For a subset of the patients, the information regarding occurrence of AVM hemorrhage after treatment of the first hemorrhage was used for further analysis of the influence on risk from AVM location and pregnancy.RESULTSThe age distribution for the first AVM hemorrhage was used to determine the average annual risk for hemorrhage in unruptured AVMs at adult ages (25-60 years). It was concluded to be 3.1% ± 0.2% and unrelated to AVM volume but influenced by its location, with the highest risk for centrally located AVMs. The hemorrhage risk was found to be significantly higher for females in their fertile years.CONCLUSIONSThe present methodology allowed the authors to determine the average annual risk for the first AVM hemorrhage at 3.1% ± 0.2% without the need for individual patient follow-up. This methodology has potential also for other similar types of investigations. The conclusion that centrally located AVMs carry a higher risk was confirmed by follow-up information. Follow-up information was also used to conclude that pregnancy causes a substantially greater AVM hemorrhage risk. The age distribution for AVM hemorrhage is incompatible with AVMs present at birth having the same hemorrhage risk as AVMs in adults. Plausibly, they instead develop in the early years of life, possibly with a lower hemorrhage risk during that time period.

Cerebral arterio-venous malformations in the paediatric population: Angiographic characteristics, multimodal treatment strategies and outcome

OBJECTIVES

Cerebral arterio-venous malformations (AVM) are considered congenital lesions, emerging as an important cause of haemorrhagic stroke in children. The potential influence of age on clinical presentation and angio-architecture have been analysed extensively in the last years. Yet, comparative studies comprising ascending age groups may be limited in their conclusions, especially when comparing young children and adults. It is the aim of this study to evaluate characteristic clinical and angiographic features of AVM within a paediatric subgroup and their correlation to age at presentation.

PATIENTS AND METHODS

Between 1990-2015, 46 children harbouring AVMs were treated at our institution. Clinical presentation, radiological data, treatment strategies and outcome were evaluated retrospectively.

RESULTS

Of 46 consecutive patients, 18 were male and 28 female patients. Mean age was 11.6±4.3years, ranging from 2 to 17 years. 35 patients (76%) presented with haemorrhage. Seizures were found in 6 patients (13%) and progressive or transient focal neurological deficits in 4 individuals (9%). There was one incidental patient, only. Mean age of children presenting with haemorrhage was significantly lower as compared to those without a history of intracranial bleeding (p=0.1). The size of the AVM was small (n=27, 59%), corresponding a grade I AVM in the majority of patients (N=28, 61%). 41 patients (89%) underwent treatment of their AVM by an interdisciplinary approach achieving complete elimination of the lesion in 34 patients (83%). 34 patients (83%) showed at least a favourable outcome (mRS≤2) at last follow-up. An excellent recovery (mRS 0-1) was noted in 28 patients (68%).

CONCLUSION

From our data we suggest that patients' age impacts the clinical presentation. Particularly young children seem to bear a higher risk for haemorrhage from their AVM. Treatment of paediatric AVMs can be achieved safely in experienced hands with a high rate of complete elimination and good clinical outcome.

Are parenchymal AVMs congenital lesions?

A long-held dogma in neurosurgery is that parenchymal arteriovenous malformations (AVMs) are congenital. However, there is no strong evidence supporting this theory. An increasing number of documented cases of de novo formation of parenchymal AVMs cast doubt on their congenital nature and suggest that indeed the majority of these lesions may form after birth. Further evidence suggesting the postnatal development of parenchymal AVMs comes from the exceedingly rare diagnosis of these lesions in utero despite the widespread availability of high-resolution imaging modalities such as ultrasound and fetal MRI. The exact mechanism of AVM formation has yet to be elucidated, but most likely involves genetic susceptibility and environmental triggering factors. In this review, the authors report 2 cases of de novo AVM formation and analyze the evidence suggesting that they represent an acquired condition.