Reply:

We would like to sincerely thank Dr Niemczyk for his commentary on our recent article. We agree that despite the increased risks of aneurysm repair in patients with autosomal dominant polycystic kidney disease (ADPCKD), aneurysm screening programs are beneficial in this population.¹ The issue then arises of how to risk-stratify these patients once aneurysms are discovered. As Dr Niemczyk states, the aneurysms in this patient population must be treated as unique entities and the traditional risk-stratification methods may not be entirely accurate. While it is known that patients with ADPCKD present with subarachnoid hemorrhage earlier in life compared with the general population, once the aneurysm ruptures, they have mortality rates similar to those of the general population.^2⇓⇓–5 Little else is known, however, about the potentially increased risks of rupture in this patient group.

The recently published Unruptured Intracranial Aneurysm Treatment Score lists ADPCKD as an independent risk factor for rupture, with a risk score equivalent to that of hypertension, drug abuse, and Japanese or Finnish ethnicity.⁶ Another recently published PHASES (Population, Hypertension, Age, Size of Aneurysm, Earlier SAH, and Site of Aneurysm) scoring system does not specifically take into account ADPCKD status but does state that Finnish or Japanese ethnicity increases the risk of aneurysm rupture by 2.0–3.6 times.⁷ These findings raise the question of whether patients with ADPCKD should be approached with a treatment paradigm similar to that in these high-risk groups.

We recommend that all treatment-related decisions be made on an aneurysm- and patient-specific basis by multidisciplinary consensus. With this in mind, further research is needed to better risk-stratify aneurysms in patients with ADPCKD.

• © 2016 by American Journal of Neuroradiology