The exact causes of the degenerative process remain unclear. There are, however, some hypotheses and well-defined risk factors. * Tobacco smoking: More than 90% of people who develop an<unk>  have smoked at some point in their lives. * Alcohol and hypertension: The inflammation caused by prolonged use of alcohol and hypertensive effects from<unk>  edema which leads to hemorrhoids, esophageal varices, and other conditions, is also considered a long-term cause of<unk> . * Genetic influences: The influence of genetic factors is high.<unk>  is four to six times more common in male siblings of known patients, with a risk of 20–30%. The high familial prevalence rate is most notable in male individuals. There are many hypotheses about the exact genetic disorder that could cause higher incidence of<unk>  among male members of the affected families. Some presumed that the influence of alpha 1-antitrypsin deficiency could be crucial, while other experimental works favored the hypothesis of X-linked mutation, which would explain the lower incidence in heterozygous females. Other hypotheses of genetic causes have also been formulated. Connective tissue disorders, such as Marfan syndrome and Ehlers-Danlos syndrome, have also been strongly associated with<unk> . Both relapsing polychondritis and pseudoxanthoma elasticum may cause<unk> . * Atherosclerosis: The<unk>  was long considered to be caused by atherosclerosis, because the walls of the<unk>  frequently carry an atherosclerotic burden. However, this hypothesis cannot be used to explain the initial defect and the development of occlusion, which is observed in the process. * Other causes of the development of<unk>  include: infection, trauma, arteritis, and cystic medial necrosis.
Abdominal aortic aneurysm
Appendicitis
Superior mesenteric artery syndrome
Splenic infarction
Aortoenteric fistula
Postcholecystectomy syndrome
Renal vein thrombosis
Spontaneous bacterial peritonitis