Fatal nonocclusive mesenteric ischaemia: population-based incidence and risk factors.

Objectives: To estimate the incidence and extension of visceral organ infarction, and to evaluate potential causes, in patients with autopsy-verified nonocclusive mesenteric ischaemia (NOMI) and transmural intestinal infarction.

Setting: In Malmö, Sweden, the autopsy rate between 1970 and 1982 was 87%, creating possibilities for a population-based study.

Design: Amongst 23 446 clinical autopsies, 997 cases were coded for intestinal ischaemia in a database. In addition, 7569 forensic autopsy protocols were analysed. In a nested case-control study within the clinical autopsy cohort, four NOMI-free controls, matched for gender, age at death and year of death, were identified for each fatal NOMI case to evaluate risk factors.

Results: The overall incidence of autopsy-verified fatal NOMI was 2.0/100,000 person-years, increasing with age up to 40/100,000 person-years in octogenarians. Patients with stenosis of the superior mesenteric artery (SMA; n = 25) were older (P = 0.002) than those without (n = 37), and had more often a concomitant stenosis of the coeliac trunk (P < 0.001). Synchronous infarction in the liver, spleen or kidney occurred in one-fifth of all patients. Fatal cardiac failure [OR 2.9 (1.7-5.2)], history of atrial fibrillation [OR 2.2 (1.2-4.0)] and recent surgery [OR 3.4 (1.6-6.9)] were risk factors for fatal NOMI.

Conclusions: Fatal heart failure was the leading cause of intestinal hypoperfusion, although stenosis of the SMA and coeliac trunk, atrial fibrillation and recent surgery contributed significantly. Collaboration across specialties seems to be of utmost importance to improve the prognosis.