Treatment for Acute Limb Ischemia ― Japanese Real-World Data From Active Facilities ―
Article ID: CJ-23-0611
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Article ID: CJ-23-0611
Acute limb ischemia (ALI) is a life-threatening disease with a poor prognosis.1 Surgical revascularization (SR) has traditionally been the mainstream treatment for ALI, but endovascular revascularization (ER) and hybrid revascularization (HR) are now being increasingly performed because of advancementsin transcatheter treatment.2 However, in Japan, little real-world data exist regarding the treatment of ALI.3,4 According to a report from a Japanese nationwide registry, the number of cases requiring endovascular therapy (EVT) for ALI is approximately 600 cases per year, which means that experience at every single facility is limited.4 The EndDOvascular treatment (Edo) registry reported the status of patients with ALI in Japan, but is also limited to data from 70 patients with ALI in 10 facilities.
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In this issue of the Journal, Tan et al5 report on the RESCUE ALI (REtroSpective multicenter study of endovascular or surgical intervention for Acute Limb Ischemia) study, which shows how ALI cases have been treated in Japan. The study enrolled 185 consecutive ALI patients treated with SR, ER, or HR at 6 Japanese medical hospitals between January 2015 and August 2021. The primary endpoint was the 1-year amputation-free survival (AFS) rate, and the secondary endpoints included overall survival (OS), technical success, and perioperative complications. The study found that the 1-year AFS and OS rates were 69.2% and 74.6%, respectively, consistent with previous reports.3 Severe ALI (Rutherford category IIb and III), supra- to infra-popliteal lesions, and technical failure were identified as independent risk factors for a decreased 1-year AFS. Patients with multiple risk factors showed significantly lower AFS rates. In the absence of these 3 risks, the 1-year AFS rate was higher (92.5%), thus indicating a favorable outcome. The study also observed that the prevalence of Rutherford categories IIb and III was higher in the ER group than in the SR and HR groups. Technical success and perioperative complications did not differ among the revascularization strategies. RESCUE ALI may represent real-world data from Japanese facilities with high activity and may therefore be an indicator of ALI therapy in Japan.
The treatment strategy for ALI in Japan is usually determined by interventional cardiologists or vascular surgeons based on the observed patient characteristics, lesion location, and complexity, but also greatly influenced by the healthcare team and the facility. What is noteworthy in the RESCUE ALI study is that it was a collaborative effort of cardiologists and vascular surgeons in a “real-world” setting, thus allowing for fair comparisons of all available treatment options at any one time.5 The distribution of treatment options was similar to that in the EDO registry.3 Furthermore, most of the Fogarty catheter thrombectomies were performed using angiography, which is recommended in the latest Japanese guidelines because blind Fogarty procedures carry various risks, such as residual thrombus and vessel injury.6
Supra- to infra-popliteal lesions are another important factor that affects the prognosis of ALI and chronic life-threatening ischemia (CLTI).1,4 Patients requiring EVT for such lesions are known to be at high risk for poor limb outcomes.1,4 In RESCUE ALI, supra- to infra-popliteal lesions were an independent risk factor not only in the ER group, but also the SR and HR groups. Thus, to treat these lesions appropriately, an increasing number of HRs might be needed. Indeed, a study from the American National Inpatient Sample Database (n=21,553) showed that the number of HRs (n=4,640) was nearly equal to that of ERs (n=5,008) and SRs (n=5,476).7
Lags in either devices or medications may affect the treatment strategy for ALI in Japan. For instance, the aspiration thrombectomy devices used in Japan are often small thrombectomy devices purposed for coronary thrombi, which is completely different from the Indigo system.8 Similarly, rhyolitic pharmacochemical thrombectomy and ultrasound-accelerated thrombolysis, which may lead to changes in treatment practice, have not yet been introduced in Japan.9,10 There is also limited availability in Japan of the various thrombolytic drugs.11 Because of the rapid developments in both devices and drugs that can improve ALI treatment in our daily practice, it is more important than ever to reduce any lags in their use in Japan.
Although the study had several limitations, including its retrospective nature, small sample size, and potential site and selection biases, it nevertheless provides valuable insights into the real-world practice of revascularization procedures for ALI and identifies some important prognostic factors. We truly appreciate and congratulate the authors of the RESCUE ALI study on their efforts to elucidate Japanese ALI treatment.
