Clinical and angiographic characteristics of below-the-knee arterial disease: A case series study from Vietnam.

Background: Below-the-knee peripheral arterial disease (BTKPAD) is a major cause of chronic limb-threatening ischemia (CLTI), yet data on its clinical and angiographic presentation in resource-limited settings remain scarce. This study aimed to characterize the clinical staging and angiographic features of patients with BTKPAD at the time of hospital admission.

Methods: A retrospective consecutive case series study was conducted at the University Medical Center Ho Chi Minh City from January 2022 to September 2024. A total of 127 patients diagnosed with BTKPAD were included. A standardized diagnostic work-up was performed for all patients. Clinical staging was assessed using the Rutherford and Fontaine classifications. Diagnostic angiography (DSA) was performed to evaluate lesion morphology, number, length, and runoff scores. Ischemia severity and lesion complexity were assessed using the ankle-brachial index (ABI) and TASC II classification, respectively.

Results: Most patients presented with advanced CLTI: 96.1 % were classified as Rutherford category 5-6 and Fontaine stage IV. The median ABI was 0.55, with over 70 % having ABI < 0.90. Tissue loss or gangrene was the primary cause of admission in 93.7 % of cases. DSA revealed multisegmental disease, with 77.2 % of patients having two to three lesion sites and a median lesion length of 14 cm. TASC classification showed 68.5 % had type C and 25.2 % had type D lesions. The median runoff score was 8.0, indicating severe distal hypoperfusion.

Conclusions: Patients with BTKPAD in this cohort predominantly presented with late-stage disease and complex vascular lesions. These findings underscore the need for earlier diagnosis and timely revascularization strategies to improve limb salvage in similar healthcare settings.