Hemodynamic Simulation of Pancreaticoduodenal Artery Aneurysm Formation Using an Electronic Circuit Model and a Case Series Analysis

Abstract

Objective : To assess mechanisms underlying aneurysm formation using a simple electronic circuit model. Materials and Methods : We created a simple circuit model connecting the celiac artery (CA) to the superior mesenteric artery via the pancreaticoduodenal arcade. We retrospectively reviewed 12 patients with true pancreaticoduodenal artery aneurysms (PDAAs) who received open or endovascular treatment between 2004 and 2017. We set the resistance of each artery and organ voltage and calculated flow volume and rate in response to degrees of simulated CA stenosis from 0% to 99.9%. Results : Flow volume rates of the anterior pancreaticoduodenal artery and posterior pancreaticoduodenal artery decreased to zero when CA stenosis increased from 0% to 50% and then increased drastically, at which point flow direction reverted and the flow was up to three times the initial rate. The gastroduodenal artery (GDA) also showed reversed flow with severe CA stenosis. In 12 patients with PDAA, eight presented with a CA lesion, and the other patients presented with comorbidities causing the arteries to be pathologically fragile, such as Marfan syndrome, Behçet’s disease, and segmental arterial mediolysis. All four GDA aneurysms were not accompanied by CA lesions. Conclusion : The mechanism underlying CA-lesion-associated PDAA formation may be partially explained using our model.

Causal Relationship between Celiac Stenosis and Pancreaticoduodenal Artery Aneurysm: Interpretation by Simulation Using an Electric Circuit

“…The results showed that the preoperative condition (time interval 4-5 sec and 11-12 sec) can be reached with either scenario, with the same clinical postoperative status (time interval 6-7 sec and 13-14 sec). Miyahara et al [20] developed an electric model of PDA aneurysm with CA stenosis and showed that as the CA stenosis progressed, the flow through the anterior and posterior PDA decreased, changed their direction, and then increased drastically. They concluded that this increase in the PDA flow might have contributed to the development of a PDA aneurysm.…”

Aneurysms of pancreaticoduodenal arcade: Clinical profile and endovascular strategies

“…Kazuhiro et al . have studied hemodynamic simulation of PDAA using an electric circuit model 23 . They showed that flow volume of the anterior pancreatoduodenal artery and the posterior pancreatoduodenal artery decreases until the CA stenosis progresses up to 50%; thereafter, it increases to up to three times that of the initial volume with retrograde flow.…”

“…However, the nonatherosclerotic, inflammatory, mycotic, or false VAAs have a higher risk of rupture, independent of size 4 . In pseudoaneurysms, it is structural wall stress, rather than hemodynamic stress, that drives the arterial wall to deteriorate and ultimately rupture 23,24 . Tulsyan et al .…”

“…4 In pseudoaneurysms, it is structural wall stress, rather than hemodynamic stress, that drives the arterial wall to deteriorate and ultimately rupture. 23,24 Tulsyan et al describe rupture rates ranging from 2.3 to 18%, with mortality rates ranging from 20 to 100%. 25 In another series, the mean size at time of rupture was reported to be 9 mm.…”

Reply

“…to a pulsatile reversed flow in the GDA akin to that observed in the CHA. (3) As published earlier by our group, the same principle is applied to perfuse the native liver in auxiliary partial orthotopic liver transplantation, thus providing a real-world proof of concept. (4) As shown in our series, GDA flow is adequate to perfuse grafts irrespective of graft size.…”