A pilot study of pancreaticoduodenal artery aneurysms concomitant with coeliac artery stenosis: Using computational haemodynamics to better understand a rare disease

Abstract

Abstract Pancreaticoduodenal artery aneurysms have been associated with coeliac artery stenosis or occlusion. These aneurysms are rare, and their size may not be predictive of rupture risk. Wall shear stress has a potential role in the initiation, development and rupture of aneurysms. We investigated the influence of coeliac artery stenosis on wall shear stress in developing PDA aneurysm and in both ruptured and intact aneurysms to determine if ruptured aneurysms experience low WSS compared to intact cases. Computed tomography imaging was retrospectively collected and reconstructed into three-dimensional geometries with which blood flow simulations were performed to compare aneurysm wall shear stress between ruptured vs intact groups. Aneurysm initiation was investigated by digitally augmenting a case to represent a healthy geometry, with incremental coeliac artery stenosis then virtually applied. Coeliac artery stenosis resulted in gastroduodenal artery flow reversal and increased wall shear stress in the inferior pancreaticoduodenal arteries, where wall shear stress reached reaching 7.55 Pa at 80% stenosis. Wall shear stress was lower in ruptured aneurysms compared to intact cases (0.23(0.25) Pa vs. 0.37(0.26) Pa). Aneurysm WSS was not correlated to diameter (rs = 0.196, p = .564). Our results suggest 70% to 80% CA stenosis as a threshold for flow reversal through the inferior PDA and GDA, with corresponding high levels of WSS in the IPDA which may be responsible for the aneurysm initiation.