Pulmonary arteriovenous malformation as a cause of ischaemic stroke in the elderly

Personalised stroke evaluation and management: tailoring individualised patient care for hereditary haemorrhagic telangiectasia

SummaryHereditary haemorrhagic telangiectasia (HHT) has an estimated prevalence of 1 in 5000-8000 individuals globally with pulmonary arteriovenous malformations (PAVMs) affecting approximately 15%-50% of HHT patients. Ischaemic stroke is a known complication of PAVMs that affects ≤30% of patients with PAVMs. Studies have shown that patients with PAVMs have ischaemic stroke a decade earlier than routine stroke. The predominant mechanism of ischaemic stroke in HHT patients is paradoxical embolism due to PAVMs, but most HHT-related PAVMs are asymptomatic. Additionally, HHT is often underdiagnosed in patients and poses a challenge to physicians due to its rarity. We present a case of a patient with ischaemic stroke who was subsequently diagnosed with HHT and found to have a PAVM on further evaluation. This case highlights the importance of using an individualised patient-centred stroke evaluation and screening for PAVMs in patients who had a stroke with possible or suspected HHT and definite HHT.

Pearls and Pitfalls in the Transesophageal Echocardiographic Diagnosis of Patent Foramen Ovale

Large randomized controlled trials have shown the benefits of percutaneous closure of patent foramen ovale (PFO) in patients with cryptogenic stroke and PFO. Recent studies have highlighted the clinical significance and prognostic implication of various anatomical features of PFO and the adjacent atrial septum, such as atrial septal aneurysm (ASA), PFO size, large shunt, and hypermobility. Transthoracic echocardiography with contrast study is used for the indirect diagnosis of PFO, as it reveals the passage of the contrast into the left atrium. In contrast, transesophageal echocardiography (TEE) offers a direct demonstration of PFO by measuring its size using the maximum separation distance between the septum primum and septum secundum. Furthermore, TEE enables the acquisition of detailed anatomical features of the adjacent atrial septum including ASA, hypermobility, and PFO tunnel length, which carry significant prognostic implications. Transesophageal echocardiography also facilitates the diagnosis of pulmonary arteriovenous malformation, a relatively rare cause of paradoxical embolism. This review provides evidence for supporting TEE as a useful screening test for patients with cryptogenic stroke to identify suitable candidates for percutaneous device closure of PFO. Additionally, cardiac imaging specialists with proficiency in comprehensive TEE examination should be part of the heart-brain team for proper evaluation of and decision-making in patients with cryptogenic stroke.

Concurrent pulmonary arteriovenous malformation and pulmonary embolism causing stroke: a therapeutic dilemma

Background

As pulmonary arteriovenous malformation (PAVM) include a right-to-left shunt, it can be accompanied by fatal complications such as stroke and brain abscess due to paradoxical embolism. A concurrent PAVM and pulmonary embolism (PE) is a rare condition. Therefore, the sequence of management has not been established.

Case presentation

A 62-year-old female patient was transferred to our hospital with a sporadic simple PAVM and concurrent bilateral PE. On chest computed tomography (CT), the acute PE was extended to the segmental pulmonary artery where the feeding artery of PAVM originated. Despite the anticoagulation, the patient complained of left sided weakness on the fifth day of admission, and magnetic resonance imaging revealed an acute infarction in the right lateral thalamus, which was thought to be caused by paradoxical embolism. This situation could lead to a dilemma between the risk of thrombus migration during PAVM embolization and another embolic event due to delayed shunt occlusion during anticoagulation. After a multidisciplinary discussion, a delayed endovascular embolization was performed for PAVM after confirming the complete resolution of PE with 4 months of anticoagulation. The cause of PE in this patient was eventually diagnosed as antiphospholipid syndrome.

Conclusion

The authors reported a rare case of concurrent PAVM and PE that led to an embolic stroke during hospitalization. This patient was managed with delayed endovascular embolization for PAVM after an anticoagulation for PE and stroke. It is thought to be valuable in deciding for a treatment plan for this rare condition.