Renal angiography in children with polyarteritis nodosa

This study describes the angiographic findings in children with polyarteritis nodosa (PAN). Visceral angiograms of 25 children with PAN were reviewed retrospectively by two independent radiologists. In the PAN group, 40% of children had aneurysms demonstrated on selective renal angiography. Most aneurysms affected small and medium-sized arteries. There was agreement between radiologists regarding medium and large aneurysms (K=0.81), but less so for smaller aneurysms. Overall, the presence of medium or large aneurysms was significantly associated with the presence of renal impairment and hypertension. Non-aneurysmal changes were detected more commonly on renal angiography than aneurysms in the PAN group. The most reliable non-aneurysmal signs were perfusion defects, the presence of collateral arteries, lack of crossing of peripheral renal arteries, and delayed emptying of small renal arteries. The sensitivity and specificity of renal angiographic diagnosis of PAN using aneurysms alone was 43% (SE 10%) and 69% (SE 14%) respectively. The sensitivity increased to 80%, and specificity fell to 50% for angiogram positivity defined as the presence of at least one of the most reliable non-aneurysmal signs irrespective of the presence of aneurysms. Aneurysms were also demonstrated on hepatic and mesenteric angiography, and non-aneurysmal signs were found on hepatic, mesenteric, and splenic angiography, although interobserver agreement for angiographic findings in these vascular beds was lower. It is important to consider both aneurysmal and non-aneurysmal angiographic signs, and to include examinations of several vascular beds when utilising angiography for diagnostic purposes in children with PAN.