Objectives: This is an annual report indicating the number and early clinical results of annual vascular treatment performed by vascular surgeons in Japan in 2019, as analyzed by database management committee (DBC) members of the JSVS.

Materials and Methods: To survey the current status of vascular treatments performed by vascular surgeons in Japan, the DBC members of the JSVS analyzed the vascular treatment data provided by the National Clinical Database (NCD), including the number of treatments and early results such as operative and hospital mortality.

Results: In total 154,460 vascular treatments were registered by 1,082 institutions in 2019. This database is composed of 7 fields including treatment of aneurysms, chronic arterial occlusive disease, acute arterial occlusive disease, vascular injury, complication of previous vascular reconstruction, venous diseases, and other vascular treatments. The number of vascular treatments in each field was 23,826, 17,100, 4,947, 2,369, 674, 54,023, and 51,521, respectively. In the field of aneurysm treatment, 20,369 cases of abdominal aortic aneurysm (AAA) including common iliac aneurysm were registered, and 63.3% were treated by endovascular aneurysm repair (EVAR). Among AAA cases, 1,739 (8.5%) cases were registered as ruptured AAA. The operative mortality rates of ruptured and un-ruptured AAA were 15.0%, and 0.6%, respectively. 43.8% of ruptured AAA were treated by EVAR, and the EVAR ratio was gradually increasing, but the operative mortality rates of open repair and EVAR for ruptured AAA were 12.6%, and 15.4%, respectively. Regarding chronic arterial occlusive disease, open repair was performed in 8,026 cases, including 1,250 distal bypasses to the crural or pedal artery, whereas endovascular treatment (EVT) was performed in 8,879 cases. The EVT ratio was gradually increased at 51.9%. Varicose vein treatment was decreased in 42,313 cases (1.9% less than in 2018), and 79.8% of the cases were treated by endovenous thermal ablation (ETA) including endovenous laser ablation (EVLA) and radio-frequency ablation (RFA). Regarding other vascular operations, 47,605 cases of vascular access operations and 1,703 lower limb amputation surgeries were included.

Conclusions: The number of vascular treatments increased since 2011, and the proportion of endovascular procedures increased in almost all fields of vascular diseases, especially EVAR for AAA, EVT for chronic arterial occlusive disease, and ETA for varicose veins. (This is a translation of Jpn J Vasc Surg 2024; 33: 307–335.)

Postthrombotic syndrome (PTS) can cause both venous outflow obstruction and deep venous reflux, and results in severe symptoms of chronic venous disease. Venous stenting in the chronic iliocaval venous obstruction has been shown to be a safe and efficacious procedure. The long-term studies have shown the high patency rate, the good symptom relief, and the low recurrence rate of healed venous ulcerations. Although venous stenting has become a widely accepted treatment option in PTS with chronic venous occlusion or severe stenosis, it is not yet covered by insurance in Japan, and is being performed at limited facilities using off-label arterial stents. In this study, we performed venous stenting in 30 patients with the moderate and severe PTS. All patients showed significant improvement in their venous scores postoperatively, the Villalta score changed from a median of 16 before treatment to a median of 7 after treatment. Likewise, the Venous Clinical Severity Score and the Venous Disability Score dropped from a median of 13, 2.4 before treatment to 6, 1.2 after treatment, respectively. The primary patency and the secondary patency at 40 months were 93% and 96%, respectively. We report the excellent results and discuss current issues and future perspective in Japan. (This is secondary publication from J Jpn Coll Angiol 2021; 61: 99–105.)

Takayasu’s arteritis, first described by Dr. Mikito Takayasu in 1908, is a systemic vasculitis that mostly affects the aorta and its major branches. Although the etiology of the disease is yet unknown, genetic and environmental factors may both play a role. One hundred years after the discovery of Takayasu’s arteritis, inflammation is finally widely recognized as a fundamental condition common to all vascular diseases, and clinical trials have proven the efficacy of molecularly targeted drugs that block each step of the NLRP3 inflammasome/interleukin (IL)-1β/IL-6 cascade in patients with atherosclerotic vascular disease and elevated C-reactive protein (CRP). Recent advances have also been made in the treatment of Takayasu’s arteritis. The randomized controlled trials and subsequent open-label and post-marketing surveillance studies in Japan have demonstrated that tocilizumab, an anti-IL-6 receptor antibody, is effective in the treatment of Takayasu’s arteritis and prevents relapse during tapering of prednisolone doses. IL-6 is also heavily engaged in the remodeling of large vessels after acute aortic dissection as demonstrated in animal studies. In patients with acute aortic dissection, those with markedly elevated CRP levels in the acute phase are known to have an increased risk of aorta-related events, such as rupture due to aortic diameter enlargement, in the subacute and chronic phases. We discovered that elevated CRP levels following aortic dissection are caused by IL-6, which is produced by neutrophils that infiltrate the adventitia of the dissected aorta. In a mouse model of acute aortic dissection, we showed that IL-6 produced by these neutrophils causes progressive destruction of the arterial wall structure and that blockade of IL-6 signaling can prevent post-dissection vascular remodeling and improve life outcome. Therefore, inhibiting IL-6 signaling is anticipated to be effective in the secondary prevention of myocardial infarction and suppression of vascular modeling after dissection and even as an anti-inflammatory therapy for Takayasu’s arteritis; however, this approach does not solve everything. Undoubtedly, the mechanisms of inflammation in vascular disease are diverse and complex, and the cytokines and cell populations involved at each site (coronary artery vs. aorta) and in each phenotype (atherosclerosis vs. aortic aneurysm vs. aortic dissection) need to be understood for each type of inflammation. Osteopontin (OPN) is a recruiter of monocytes and macrophages, induces cellular immune responses as a Th1 cytokine, acts as a fibrosis-promoting factor, and has been shown to be deeply involved in the pathogenesis of vascular diseases. We have shown that senescent T cells, which emerge with obesity and aging, secrete significant amounts of OPN, leading to metabolic abnormalities and chronic inflammation. Neutrophil extracellular traps (NETs) released from activated neutrophils have been shown to contribute to the pathogenesis of acute coronary syndromes (ACS) by interacting with macrophages, platelets, and vascular endothelial cells and thus promoting plaque erosion and immunothrombosis. In addition to standard anticoagulant and antiplatelet therapies, the effectiveness of anti-immunothrombotic therapies targeting NETs as a new preventive and therapeutic approach for ACS will be examined in the future.

Isolated superior mesenteric artery dissection (ISMAD) is a rare pathology with multifactorial etiology. The aim of this article is to provide a narrative review of the latest literature about ISMAD. Case reports, series, and recent meta-analyses were included. This review is introduced with a brief case report of a rare etiology of ISMAD, followed by a discussion of its etiology, clinical presentation, diagnosis, classification, and treatment, and we report a new cause of ISMAD, that is, blunt abdominal trauma. The etiology of ISMAD is multifactorial, consisting of anatomic, genetic, and systemic components. ISMAD is more common among middle-aged males and in East Asia. Its clinical presentation ranges from asymptomatic to mesenteric ischemia, albeit mortality remains <1%. It is diagnosed and classified mostly by computed tomography angiography, and there are five classification systems for ISMAD, though traumatic etiology may be added. The treatment of ISMAD is mostly conservative, with a success rate exceeding 90%. Endovascular stenting is second line, reserved so far for failed medical management, though its role is expanding to include earlier management of symptomatic patients, while open surgical repair is left for acute mesenteric ischemia with bowel compromise.

Since 2013, the Japanese Society for Vascular Surgery has started the project of nationwide registration and tracking database for patients with critical limb ischemia (CLI) who are treated by vascular surgeons. The purpose of this project is to clarify the current status of the medical practice for the patients with CLI to contribute to the improvement of the quality of medical care. This database, called JAPAN Critical Limb Ischemia Database (JCLIMB), is created on the National Clinical Database and collects data of patients’ background, therapeutic measures, early results, and long-term prognosis as long as 5 years after the initial treatment. The limbs managed conservatively are also registered in JCLIMB, together with those treated by surgery and/or endovascular treatment. In 2020, 1299 CLI limbs (male 890 limbs: 69%) were registered by 85 facilities. Arteriosclerosis obliterans has accounted for 99% of the pathogenesis of these limbs. In this manuscript, the background data and the early prognosis of the registered limbs are reported. (This is a translation of Jpn J Vasc Surg 2023; 32: 363–391.)