A 59-year-old woman with a past medical history of smoking, hypertension, and claudication was transferred from an outside hospital for further management of acute, diffuse abdominal pain, worst in the right lower quadrant, as well as nausea and vomiting. She was previously seen at the outside institution for similar symptoms, and at that time she was diagnosed with acute cholecystitis and taken to the operating room for laparoscopic cholecystectomy. Intraoperatively, it was found that the gallbladder was not inflamed. After conversion to an open procedure, however, a loop of necrotic jejunum was identified that was resected and primarily reconstructed. The superior mesenteric artery (SMA) was palpated and found to have a normal to slightly diminished pulse. Upon further review of her symptoms, she admitted to approximately 6 months of intermittent, sharp abdominal pain that was most pronounced after eating. Just prior to her acute presentation, the abdominal pain worsened sufficiently to decrease her oral intake.
The term “mesenteric ischemia” (MI) includes a wide array of diseases that lead to insufficiency of the mesenteric vasculature and subsequent intestinal compromise, often with dire consequences. Acute mesenteric ischemia (AMI) was first recognized as a pathologic entity in 1895, when 2 case reports of bowel resection for compromised mesenteric flow, due to venous as well as arterial thrombosis, were published.1 The fundamental finding of “pain out of proportion to physical examination” was first described in that publication. Furthermore, the acuteness of the disease process and grave prognosis were established in early reports.
Several years later, a related but distinct pathology was defined: chronic mesenteric ischemia (CMI). Brunton was one of the first to report mesenteric vascular insufficiency leading to chronic pain and weight loss.2 He also made reference to the term “angina abdominis” and credited Baccelli with its first use.
In the 1950s, surgeons addressed the cause of mesenteric ischemia and performed thrombendarterectomy of the SMA for chronic disease as well as embolectomy for acute disease.3 The understanding of mesenteric ischemia continued to evolve, as evidenced by descriptions of compressive syndromes such as median arcuate ligament syndrome.4
There are several suggestions for classification of mesenteric vascular insufficiency based on etiology: arterial vs venous, and embolic vs thrombotic. For this chapter we will focus on the radiologic and clinical evaluation of the acute forms of mesenteric ischemia and make some important distinctions about imaging options depending on the acuity of presentation. The acute-on-chronic scenario, with terminal thrombosis of an atherosclerotic SMA stenosis, as presented in the clinical scenario above, is chosen as one of the more likely presentations that general surgeons are called upon to evaluate. It is often insidious in onset, with potential for misdiagnosis and delay in care.
Overall, MI is a rare disease. Within the spectrum of this disease, however, acute presentations are much more prevalent, accounting for about ...