# Preoperative Planning for Superior Messetric Artery Aneurysm
## 1 Introduction  
A mesenteric artery aneurysm is an aneurysm that occurs in either the inferior or superior mesenteric arteries that irrigate visceral organs like the stomach. Messetric artery aneurysms are rare, with a prevalence of 5-8% of all aneurysms, and have an annual incidence of between 0.01% and 0.2% [1]. Superior mesenteric artery aneurysms are the third most common true visceral aneurysms, often affecting the proximal 5 cm of the artery [2] and accounting for 14% of all visceral aneurysms [3]. They occur predominantly in men who are in the 5 th decade of life. Aneurysmal degeneration of the superior mesenteric artery does not occur frequently, but when it does, it may result in mesenteric ischemia or rupture [4], which can initiate a potentially life-threatening condition [3]. In about 25% of cases, visceral aneurysms present as surgical emergencies [1], although the disease is often asymptomatic. They are an incidental finding in almost half of the patients [5]. Around 22% of patients with visceral aneurysms are diagnosed after rupture. Variable clinical manifestations pose the risk of misdiagnosis with a high mortality of 8.5-25% [6, 7]. There is no known cause for aneurysm, but there are several risk factors that are known of that include: family history, male gender, an age > 65, history of smoking, high blood pressure, high cholesterol, atherosclerosis, or having a connective tissue disorder like Marfans or Ehlers-Danlos syndrome. The diagnosis of a superior mesenteric artery aneurysm is made by computed tomographic angiography (CTA) or magnetic resonance (MR) and sometimes via an abdominal ultrasound examination. The suspicion of an aneurysm can be raised by a calcified wall on X-rays. In addition, the changes in the surrounding tissues and organs, like the signs of chronic pancreatitis or other events, might reveal the cause of the condition. By evaluating laboratory findings, imaging, and clinical symptoms, the factors influencing condition management should be determined and additional vascular changes might be discovered. Imaging has a very important role not only in diagnosis but also in treatment planning because on these images is possible to determine multiple parameters for surgery like aneurysal size, neck, access vessels, etc. Image processing software and virtual planning methods are already of great importance in medical practice. A long list could be made of either free-of-charge medical imaging software platforms, e.g., [8; 9], semi-commercial, e.g., [10], or commercial ones. Characteristics used for the evaluation of such platforms could be the functionalities it offers (3D rendering, segmentation, measurements, virtual simulations, etc. ), the price (from free-of-charge to very expensive), the training curve, hardware requirements, etc. In the following paper, we propose a preoperative planning protocol, which consists of four steps, namely, high-quality 3D rendering, virtual navigation (angiography) through the arteries, automatic and semi-automatic (point and click) measurements, and 3D stent simulations. These steps are exemplified and implemented via our own (in-house) software application, CardioCT Nav. The main advantages of our solutions are the quality of implementation (it is a fast, stable, and bug-free application), the price (a binary package can be provided free of charge on request), ease of use (no sophisticated and difficult segmentations are required to perform the suggested planning protocol), the brief time necessary to perform the planning (it can be completed in less than 10 min, and it has virtually no training curve), and an intuitive user interface and simple gestures that can be learned in only a few minutes. There are other methods currently being investigated that may be useful in preoperative planning. One such method is 3D printing.