Two-Year Outcomes of the Prospective THRILLER Registry on Popliteal and Infrapopliteal Endovascular Interventions for CLTI

BACKGROUND: Over 70% of patients with chronic limb-threatening ischemia (CLTI) present with below-the-knee disease, and there is a growing trend towards endovascular revascularization. OBJECTIVES: The Dutch Chronic Lower Limb-Threatening Ischemia Registry (THRILLER) aimed to provide real-world data on outcomes after popliteal and infrapopliteal endovascular revascularization to guide revascularization strategies. METHODS: This prospective multicenter registry included consecutive CLTI patients undergoing popliteal or infrapopliteal endovascular revascularization in seven Dutch hospitals. Primary outcomes were limb salvage and amputation-free survival (AFS) at 24 months, estimated using the Kaplan-Meier method. RESULTS: Between February 2021 and December 2023, a total of 1,119 interventions in 1,060 limbs (938 patients) were included, treating 551 popliteal, 1,352 tibial, and 239 pedal lesions. The median follow-up was 43.6 months (Q1-Q3: 35.5-52.7 months). Overall, 78.4% (831/1,060) of the limbs were Rutherford 5 and 8.1% (86/1,060) were Rutherford 6; 41.3% (382/926) were WIfI (Wound, Ischemia, and foot Infection) stage 4. Technical success was achieved in 92.3% (1,033/1,119). Limb salvage and AFS decreased significantly after technical failure and with increasing WIfI stage and Rutherford category. Compared to Rutherford 5, Rutherford 6 limbs had significantly worse limb salvage (HR: 3.07; 95% CI: 1.89-4.99; P < 0.001) and AFS (HR: 2.07; 95% CI: 1.50-2.86; P < 0.001). For AFS, the excess risk of Rutherford 6 was greatest in the first 3 months (HR: 14.13; 95% CI: 4.94-40.38 vs Rutherford 4; P < 0.001). CONCLUSIONS: Endovascular revascularization for popliteal and infrapopliteal disease in patients with CLTI is safe and effective in preventing limb loss and mortality at 2 years, although patients with Rutherford 6 limbs face significantly worse outcomes, particularly in the first 3 months.