A Population‐Based Study of Incidence, Presentation, Treatment and Short‐Term Outcomes of Acute Thromboembolic Ischemia in the Lower Limbs

OBJECTIVES: To investigate the current epidemiology and short-term outcomes in patients with acute lower limb ischemia (ALI) in a well-defined Norwegian population. METHODS: A retrospective, single-center, observational cohort study in a defined population catchment area. All patients with ALI from the catchment area were included in the period from January 2000 to December 2019. Age- and sex-adjusted incidence rates were calculated using population demographics from Statistics Norway. RESULTS: A total of 359 patients were identified, and 356 (99.2%) were included in the analyses. Two-thirds were males (n = 216, 60.7%), with males presenting at a younger age than females (median age 71, quartiles 63-81 yrs vs. median age 79 quartiles 67-87; respectively; p < 0.001). The age- and sex-adjusted incidence rate for the period was 7.9/100.000/year (95% confidence interval 7.1-8.8) with no significant change throughout the period. Patient distribution according to Rutherford classification was 110 (31%) class 1, 130 (36.6%) class 2a, 100 (28.2%) class 2b and 15 (4.2%) class 3. The level of occlusion was supra-inguinal in 105 patients (29.5%) and infra-inguinal in 251 (70.5%). Thrombosis was the most common cause of ischemia, observed in 243 patients (68.3%). Bilateral ischemia was recorded in 21 (5.9%) patients. In 196 (55.1%) the treatment was surgical, in 135 (37.9%) endovascular. Four patients (1.1%) underwent primary amputation, whereas 11 (3.1%) and 10 (2.8%) were managed with conservative or palliative treatment, respectively. In the first 90 days, major adverse limb events were noted in 115 patients (32.3%) and general complications in 73 (20.5%). Overall, a major amputation was performed in 47 (13.2%) within 90-days. 90-days mortality was 78 (21.9%). CONCLUSION: The incidence of ALI remained stable over the study period in this defined Nordic population, although embolic occlusions became increasingly common. ALI remained associated with substantial short-term morbidity and mortality, and females presented with more advanced ischemia and poorer amputation-free survival.