European Reference Network for Rare Vascular Diseases (VASCERN) position statement on cerebral screening in adults and children with hereditary haemorrhagic telangiectasia (HHT)

Abstract

Hereditary haemorrhagic telangiectasia (HHT) is a multisystemic vascular dysplasia inherited as an autosomal dominant trait. Approximately 10 % of patients have cerebral vascular malformations, a proportion being cerebral arteriovenous malformations (AVMs) and fistulae that may lead to potentially devastating consequences in case of rupture. On the other hand, detection and treatment related-risks are not negligible, and immediate. While successful treatment can be undertaken in individual cases, current data do not support the treatment of unruptured AVMs, which also present a low risk of bleeding in HHT patients. Screening for these AVMs is therefore controversial.

Screening for pulmonary and brain vascular malformations is the North American standard of care for patients with hereditary hemorrhagic telangiectasia (HHT): A survey of HHT Centers of Excellence

“…Recently, the European position was reiterated in a position statement from the European Reference Network for Rare Vascular Diseases (VASCERN) on brain VM screening in adults and children with HHT. 8 …”

“… 4 , 6 As such, preventative intervention is not recommended for all patients; the risks of the treatment must be balanced against the risk of spontaneous intracranial hemorrhage without treatment. 8 , 10 – 13 Since publication of the HHT International Guidelines, 4 the controversy regarding brain VM screening has continued to evolve. Non-HHT brain VM studies, such as the ARUBA trial, have suggested that sporadic brain VMs, if asymptomatic, may be best left untreated.…”

“…In HHT-specific studies, the average risk of intracranial hemorrhage from brain VMs is estimated to be ‘low’ at 0.5–2% per year. 8 , 11 , 13 However, most of these adult studies are limited by survivor bias, and therefore likely underestimate risk of intracranial hemorrhage. A systematic review and meta-analysis of literature regarding brain VMs in HHT found that a high proportion of patients with HHT with brain VMs will experience symptoms (50%) or AVM-related hemorrhage (20%), further highlighting the role of screening in patients with HHT, which may allow for intervention prior to symptoms or complications.…”

“…All North American HHT Centers recommend routine screening for brain VM in adult patients with HHT, whereas only one out of eight VASCERN HHT Centers routinely does so. 8 …”

“…Recently, the European position was reiterated in a position statement from the European Reference Network for Rare Vascular Diseases (VASCERN) on brain VM screening in adults and children with HHT. 8 A 2017 systematic review and meta-analysis concluded that the prevalence of brain VMs in patients with HHT is approximately 10%. 9 The controversy around brain VM screening stems from the risks of treatment for brain VMs, including hemorrhage, neurological deficit, and infection.…”