American Board of Surgery Qualifying Exam (ABS QE) Practice Test

An ABI of less than 0.3 is associated with which complication?

1. Tissue loss

2. Gangrene

3. Type 4 choledochal cyst

4. Caroli's disease

The correct answer is: Gangrene

An ankle-brachial index (ABI) of less than 0.3 indicates severe peripheral arterial disease, which significantly compromises blood flow to the lower limbs. This reduced circulation makes the tissues more susceptible to ischemia, where there is insufficient blood supply to meet the metabolic demands of the tissues. When blood flow is critically diminished, it can lead to tissue death, also referred to as gangrene, because the affected tissues lack the necessary oxygen and nutrients required for survival. In situations of critical limb ischemia indicated by such a low ABI, the risk of developing gangrene is heightened. This condition can be particularly acute when an injury occurs or there is a local infection, as the body's ability to heal and fight off infections is severely limited in the context of poor blood circulation. Consequently, gangrene may develop, leading to further complications that often necessitate surgical intervention, such as limb amputation, to prevent systemic effects or further tissue deterioration. The other options listed do not directly relate to the consequences of a low ABI. Tissue loss, while relevant, is too broad and can be attributed to various factors; however, gangrene is a more specific and severe complication that arises from the lack of blood flow suggested by the ABI value. Type 4 cho