(IP123) One-year Limb Salvage and Amputation Free Survival Following Implementation of a Novel System-wide Alert Protocol for Management of Acute Limb Ischemia

Objectives: Acute limb ischemia (ALI) remains a vascular surgical emergency with high rates of limb loss and mortality. This study reports one-year clinical outcomes of ALI management following implementation of a novel system-wide alert protocol.

Methods: A retrospective review of a prospectively maintained single-center ALI database was performed to identify all patients treated under the acute limb ischemia alert protocol from May 2022-December 2023. Analysis was focused on patients with at least one year of clinical follow up post revascularization. Patient demographic, clinical and procedural-related metrics were analyzed. Temporal measurements in the diagnostic and therapeutic phases of the alert system were assessed. Primary outcomes were thirty-day, six-month, and one-year rates of limb salvage (LS), amputation-free survival (AFS) and mortality.

Results: During the 20-month study period the alert protocol was activated 110 times, with one-year clinical follow up met in 59 patients. Rutherford class at presentation included class I (N=9,15%), IIa (N=28,48%), IIb (N=19,32%) and III (N=3,5%). The median patient age was 64 years [54, 73.5], with male sex representing 66% (N=39) of the cohort. Temporal measures of the protocol phases demonstrated: median time from triage-to-alert, 16 minutes [2, 41]; from alert-to-heparin, 83.5 minutes [38.5, 121.8]; from alert-to-imaging, 93 minutes [60.5, 125.5]; from alert-to-procedure, 6 hours [3.4, 23]. When stratified by Rutherford class, median time from alert-to-procedure noted: Class I, 28.1 hours [20.3, 58.4]; IIa, 16.6 hours [4.3, 35.4]; IIb, 3.0 hours [2.1, 5.3]. Intervention for ALI was performed in all 59 unique patients, with four patients undergoing primary amputation. Of the 55 patients receiving arterial revascularization an endovascular-first approach was utilized in 31% (N=17/55). For the entire cohort, the median time to any reintervention was 111 days [7,240]. Patients treated with an endovascular-first approach displayed increased requirements for reintervention [Endo-first, 58.8% (N=10/17) vs Open-first, 39.5% (N=15/38);p=0.183], without statistical significance. Observed LS at thirty-day, six-months, and one-year were 92.7% (N=51/55), 83.6% (N=46/55) and 81.8% (N=45/55), respectively. Observed AFS at thirty-day, six-months, and one-year were 83.6% (N=46/55), 67.3% (N=57/55) and 63.6% (N=35/55), respectively. One-year AFS was influenced by Rutherford class (Figure1). All-cause mortality at thirty-day, six-months, and one-year mortality were 9.1% (N=5/55), 16.4% (N=9/55) and 18.2% (N=10/55).

Conclusions: Implementation of a protocol-driven system-wide alert protocol in the management of ALI demonstrates sustained improvements in LS and AFS to one-year, as compared to historic values. Continued alert utilization with long-term clinical follow-up will help to further define best-practice temporal parameters and refine current treatment algorithms.