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Pulmonary arteriovenous malformation in hereditary haemorrhagic telangiectasia complicated by severe pulmonary

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HardRare Respiratory DiseasePulmonary arteriovenous malformation in hereditary haemorrhagic telangiectasia complicated by severe pulmonary arterial hypertensionSCE Respiratory

A 46-year-old woman with genetically confirmed hereditary haemorrhagic telangiectasia has exertional dyspnoea. CT pulmonary angiography demonstrates a technically accessible simple pulmonary arteriovenous malformation with an 18 mm sac and a 3.5 mm feeding artery. Resting arterial oxygen saturation is 91% on air. Haemoglobin is 174 g/L, ferritin is normal, and she has no symptoms of hyperviscosity. Echocardiography shows severe right ventricular dilatation. Right heart catheterisation records a mean pulmonary artery pressure of 52 mmHg, pulmonary artery wedge pressure of 8 mmHg, cardiac index of 2.2 L/min/m² and pulmonary vascular resistance of 10.2 Wood units. Imaging shows no hepatic arteriovenous malformation. She has had no haemoptysis, stroke or cerebral abscess. What is the most appropriate next management?

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Reveal the answer and explanation

Correct answer: C — Refer to a designated pulmonary hypertension service before deciding whether to embolise the pulmonary arteriovenous malformation

Explanation lettering: D = shown as A · E = shown as B · B = shown as C · C = shown as D · A = shown as E

Pulmonary arteriovenous malformations that are technically amenable to treatment are generally referred for embolisation, including in asymptomatic patients, because neurological complications are not reliably predicted by oxygenation or feeding-artery diameter. This patient, however, has severe precapillary pulmonary hypertension: the wedge pressure is normal and pulmonary vascular resistance is markedly elevated, while absent hepatic AVMs and a non-elevated cardiac index argue against the more usual HHT-associated high-output mechanism. Severe pulmonary hypertension is a relative contraindication to PAVM embolisation because occluding a low-resistance vascular pathway can increase pulmonary artery pressure; fatal pressure rises have been reported. Specialist pulmonary hypertension assessment must therefore precede the embolisation decision. A is the usual management of an accessible PAVM but overlooks this important exception. C is incorrect because PAVM-associated hypoxaemia is often physiologically compensated and does not itself justify routine long-term oxygen; protocol-driven repeat CT also creates avoidable radiation exposure. D is inappropriate because secondary erythrocytosis should not be venesected in the absence of hyperviscosity symptoms, and venesection would not remove the embolisation risk posed by severe pulmonary hypertension. E does not circumvent the haemodynamic problem and is not preferred when a PAVM is technically embolisable; surgery is generally reserved for selected lesions unsuitable for endovascular treatment.

Reference: British Thoracic Society Clinical Statement on Pulmonary Arteriovenous Malformations (November 2017) — https://www.brit-thoracic.org.uk/document-library/clinical-statements/pavm/bts-clinical-statement-on-pulmonary-arteriovenous-malformations-pavms/ British Thoracic Society Clinical Statement on Pulmonary Arteriovenous Malformations (November 2017) — https://www.brit-thoracic.org.uk/document-library/clinical-statements/pavm/bts-clinical-statement-on-pulmonary-arteriovenous-malformations-pavms/ BTS Clinical Statement on PAVMs (Status checked 18 August 2026) — https://www.brit-thoracic.org.uk/clinical-resources/clinical-statements/pavm/