Blog entry by Arif Khwaja
There is some nice data in this months cJASN from the Mayo clinic describing the results of extended follow up of screening for intracranial aneurysms (IAs) in patients with ADPKD. Four hundred and seven ADPKD patients were screened with MRA for asymptomatic IAs between 1989 and 2009. 38 patients were found to have IAs on screening equating to a prevalence of around 9%. The prevalence of unruptured IA (UIAs) amongst patients with a family history of IA and/or subarachnoid haemorrhage (SAH) was estimated at 21% whilst the prevalence of UIAs with no family history was much lower at 6.3%. During cumulative imaging follow-up of 243 years in only 3 patients did a de novo IA develop or increase in size.
Depending on case series the annual risk of rupture of IAs seems to be around 1.5 per year but the risk unsurprisingly is much less when Iess than 10mm. The authors conclude that screening MRA should be offered to those patients with a positive family history of aneurysmal rupture or to those with multiple family members with IAs. In such patients who are screened and found to have no IAs they recommend re-screening at 5 years. The risks of screening are made even more complex by the risks of intervention for IAs (either surgical or radiological). The data presented here justifies a selective approach to screening based primarily on family history. Click here for abstract.