The underlying mechanisms of abdominal aortic aneurysms (AAAs) are not fully understood. Given the multifactorial nature of AAA development and progression, a comprehensive approach is essential. Throughout my academic career, I conducted various studies on AAA. To better understand this mechanism, I initially developed an elastase-infused rat AAA model and applied it to nanoparticle drug delivery systems. While open surgery has traditionally been the standard treatment for AAA, endovascular aneurysm repair (EVAR) has seen significant advancements over the past 25 years. However, insufficient evidence exists regarding this novel treatment, particularly in Japan. To address this issue, we analyzed extensive datasets on EVAR using various registries, including the Japanese Committee for Stent Graft Management. Furthermore, through medical–engineering collaboration, simulation methods were utilized to generate evidence addressing clinical questions encountered in practice.

Chronic limb-threatening ischemia (CLTI) occurs in the advanced stage of peripheral artery disease and is associated with high risks of mortality and amputation. Universal management strategies are not always applicable, owing to population diversity, and the Western trials may not be applicable to Japanese patients, owing to differences in demographics and clinical profiles. This paper examines the outcomes of revascularization in Japanese CLTI patients and emphasizes the benefits of tailored management. Post-hoc analysis of the bypass versus angioplasty in severe ischemia of the leg (BASIL)-1 trial validated the use of the Global Limb Anatomic Staging System for predicting the outcomes of endovascular therapy (EVT) but not bypass surgery (BS). The SPINACH (surgical reconstruction versus peripheral intervention in patients with critical limb ischemia) registry revealed comparable 3-year amputation-free survival rates between patients who underwent EVT and those who underwent BS, with patient-specific factors such as limb status and general health influencing its success. Revascularization improved the quality of life, but benefits declined over time, especially in non-ambulatory and older patients on dialysis. Surgical reconstruction is better for preserving ambulation. Retrospective studies revealed pedal branch artery bypass as a viable option, functional independence as a predictor of survival, and zinc supplementation as promising for wound healing. Future research should focus on refining these strategies and exploring innovative approaches to overcome persistent challenges in CLTI care.

One of the factors that contribute to the development of aortic aneurysms is hemodynamic factors. In this study, we analyzed the hemodynamic changes in a stented saccular abdominal aortic aneurysm model to improve hemodynamic factors. We discovered that stenting reduced wall shear stress, mean flow velocity in the aneurysm, energy loss, and pressure loss coefficient, and improved hemodynamics around the saccular abdominal aortic aneurysm. Stenting is expected to become a new treatment modality for abdominal aortic aneurysms. (This is a translation of J Jpn Coll Angiol 2022; 62: 111–119.)

Objectives: Endovascular aortic repair (EVAR) should be performed using a less invasive procedure based on the patient’s clinical condition, as many patients who undergo this procedure are elderly and have poor surgical tolerance. We report our experience and results of percutaneous EVAR under local anesthesia in order to practice minimally invasive EVAR at our hospital.

Methods: In August 2019, we started percutaneous EVAR using Perclose ProGlide under local anesthesia. We compared the backgrounds and surgical outcomes of patients who underwent EVAR at our hospital before and after the introduction of percutaneous EVAR under local anesthesia.

Results: We included 148 patients in this study. The age at surgery and prevalence of severe renal dysfunction were significantly higher in percutaneous EVAR under local anesthesia group. The operative time and postoperative hospital stay were significantly shorter in the percutaneous EVAR group under local anesthesia.

Conclusions: The introduction of percutaneous EVAR under local anesthesia enabled minimally invasive EVAR to be performed safely even in high-risk patients. (This is a translation of J Jpn Coll Angiol 2022; 62: 1–5.).

Endovenous surgery in the treatment of varicose veins generally consists of laser or radiofrequency ablation (RFA) as endovenous thermal ablation (ETA) with a phlebectomy or foam sclerotherapy of tributary varicose veins to improve symptomatic or cosmetic problems. Nevertheless, the efficacy of their concomitant treatments is still controversial for a decade. In the guidelines of the Japanese Society of Phlebology, concomitant phlebectomy of tributary varicose veins with ETA is described that it is not recommended officially. In our hospital, RFA without concomitant phlebectomy of tributary varicose veins accounts for 74% of the RFA cases and it shows a relatively higher percentage than other institutions in Japan. The data of RFA without concomitant phlebectomy of tributary varicose veins are evenly matched in RFA with concomitant treatments in our data concerning recurrence, remnants, endovenous heat-induced thrombosis (EHIT), and complications. This article provides the conclusion that it would be acceptable to perform isolated RFA compared to RFA with concomitant phlebectomy or foam sclerotherapy of tributary varicose veins in short- and mid-term periods. In addition, concomitant treatments might contribute to rapid improvement of the short-term and better long-term outcomes, not to mention cosmetic problems that are not identified demonstrably. (This is a translation of J Jpn Coll Angiol 2022; 62: 49–54.)

Objectives: The Gore iliac branch endoprosthesis (IBE) enables internal iliac artery (IIA) reconstruction, extending the indications of endovascular aneurysmal repair (EVAR); however, the up-and-over technique is challenging. This study aimed to clarify the advantages and procedural limitations of the up-and-over technique.

Methods: From January 2019 to October 2022, 22 patients who underwent IIA reconstruction with Gore IBE were enrolled. The patients were divided into the S and Up groups that underwent IIA reconstruction using the standard and up-and-over techniques, respectively. Aortic anatomic measurements, surgical factors, and postoperative outcomes were examined.

Results: No significant differences in operative time, fluoroscopy time, contrast medium use, blood loss volume, and length of postoperative hospital stay were observed between the S (12 patients) and Up (10 patients) groups. However, the distance from the lower renal artery to the reconstructed IIA origin was considerably shorter in the Up group than in the S group. During the 19-month follow-up, no adverse events were observed in the Up group.

Conclusions: The up-and-over technique can be a valuable option for cases where IIA reconstruction is difficult with standard procedures with Gore IBE. Therefore, understanding the procedural precautions and ensuring safety are crucial to its success.

Objectives: Surgical thrombectomy has been established as an effective treatment for acute limb ischemia (ALI). Nevertheless, manipulation via the common femoral artery (CFA) to retrieve thrombus in the infra-popliteal artery sometimes proves less effective.

Methods: We retrospectively reviewed patients undergoing surgical thrombectomy for infra-inguinal ALI from January 2010 to December 2022. The primary endpoint was the rate of amputation. Secondary endpoints were technical and clinical success rates, incidence of distal embolism, and freedom from reintervention.

Results: A total of 35 patients underwent surgical thrombectomy where the popliteal artery or below is occluded. The CFA approach was utilized in 13, and the below-knee popliteal artery (BKPA) approach in 22. There were no differences in background between groups. The reintervention rate was lower in the BKPA group (BKPA group: 0% vs. CFA group: 30.8%; P = 0.01). The BKPA group showed a significantly lower incidence of distal embolism (BKPA group: 4.5% vs. CFA group: 38.5%; P = 0.02) and freedom from reintervention (BKPA group 100% at 12 months vs. CFA group: 68.7% at 12 months; log-rank P = 0.01).

Conclusions: The BKPA approach-first strategy for surgical thrombectomy in the management of ALI is feasible with better outcomes compared with the CFA approach.

Objectives: The pathophysiological mechanism of abdominal aortic aneurysm (AAA) remains unclear. We previously reported that Bifidobacterium adolescentis levels were reduced in the feces of patients with AAA by 16S ribosomal ribonucleic acid (RNA) gene sequencing. In this study, we increased the number of cases and conducted metagenomic analyses to examine bacterial genes associated with the pathophysiology of AAA.

Methods: For gut microbiota data, feces from 55 patients with AAA and 52 patients with no history of AAA, lower extremity artery disease, or coronary artery disease (control group) were collected. Metagenomic analysis was performed by collecting raw stool samples from patients. For intestinal microbiota analysis, metagenomic analysis of the fecal samples was performed.

Results: Oral bacteria, including Actinomyces oris (p <0.0001), Streptococcus salivarius (p <0.001), Lactobacillus salivarius (p <0.001), and Streptococcus sp. (p <0.001), were increased in the feces of patients with AAA. In addition, bacterial genes related to alpha lipoic acid (ALA) biosynthesis (M00882, M00883, and M00884, p <0.0001) were decreased in patients with AAA.

Conclusions: In the feces of patients with AAA, there was an increase in oral bacteria, and the expression of bacterial genes related to ALA biosynthesis was reduced. The results suggest the possibility of developing gut microbial drug treatments for AAA.

Objectives: We sought to clarify the interface pressure (IP) and its variation by applying Biflex16, a calibrated bandage, to the lower leg.

Methods: In Study I, 50 participants applied a bandage to the lower leg of a single subject in two ways: first, with 50% overlap, while the calibration rectangle became a square (Application 1), and then with 50% overlap without intentional stretch (Application 2) which served as a control. In Study II, another 51 participants applied the bandage to their lower leg via Application 1. The IP was measured at the level of the transposition of the medial gastrocnemius muscle into the Achilles tendon (B1).

Results: In Study I, the median IP (37 mmHg) and interquartile range (IQR; 9 mmHg) in the standing position were the same for Applications 1 and 2. In Study II, the obtained IP and IQR values were 38 and 12 mmHg, respectively, in the sitting position. This IP was similar to that obtained in Study I, and no correlation was found between IP and leg circumference.

Conclusions: The variation in the IP obtained by the calibrated bandage was reasonably small when applied via Application 1. The obtained IPs did not correlate with the leg circumference.

Objectives: We investigated the association between brachial-ankle pulse wave velocity (PWV) and arterial stiffness and distensibility in the aneurysmal sac of abdominal aortic aneurysm (AAA).

Methods: Data from 49 patients with AAA from June 2020 to November 2022 at Tokyo Medical University Hospital were retrospectively analyzed. Brachial-ankle PWV (cm/s) was obtained via an automated oscillometric method. Regional arterial stiffness and distensibility parameters, such as stiffness parameter (β), pressure-strain elasticity modulus (Ep, kPa), one-point PWV (PWV β, m/s), and arterial compliance (AC, mm²/kPa⁻¹), were assessed using 2-dimensional automated tissue tracking (2DTT) ultrasonography. Patients were divided into two groups: high PWV (≥1800) and low PWV (<1800).

Results: Patients with high PWV showed significantly higher β and PWV β (30.6 ± 10.1 vs. 25.2 ± 6.3, p = 0.047; 11.6 ± 2.3 vs. 10.5 ± 1.5, p = 0.048) and significantly lower AC in the aneurysmal sac (10.6 ± 5.3 vs. 14.7 ± 8.1, p = 0.045) than those with low PWV. AC was negatively correlated with PWV (r = −0.361, p = 0.011).

Conclusions: Brachial-ankle PWV can reflect arterial stiffness and distensibility, as measured by 2DTT ultrasonography, in the aneurysmal sac of AAA, suggesting its potential as an elasticity index for assessing regional arterial stiffness and distensibility in AAA.

Objectives: The objective of this research was to examine the occurrence, clinical features, treatment approaches, and results associated with a rare complication of thrombosis of the popliteal artery after total knee arthroplasty (TKA), leading to acute limb ischemia (ALI).

Methods: A retrospective study on 1020 TKA procedures spanning 5 years. Cases of ALI were identified through clinical evaluation and arterial Doppler studies. Peripheral angioplasty was done to recanalize the popliteal artery. Manifestations, complications, and management strategies were evaluated.

Results: Among the 1020 TKA cases, 5 cases of ALI were identified which accounts for 0.49% of all TKA cases. Female predominance and left-sided presentations are notable observations. Most patients presented within 8 hours of symptom onset with diverse complications ranging from foot drop to compartment syndrome. Except for 1 case, all patients recovered with thrombosuction and balloon dilatation.

Conclusions: A rare but potentially fatal complication of TKA is popliteal artery thrombosis leading to ALI so it becomes important for early recognition and intervention to mitigate the adverse outcomes. In our study, endovascular treatment has emerged as the preferred modality in terms of effective management and reducing complications and morbidity from surgical procedures.

Persistent sciatic artery (PSA) is an exceptionally rare vascular condition that occurs in approximately 0.025%–0.04% of the general population. We describe the case of a 51-year-old man who presented with acute left lower limb pain and high fever. He was diagnosed with COVID-19 and isolated, and conservative treatment was performed for toe pain, resulting in left toe necrosis. Computed tomography revealed PSA occlusion in the left lower extremity. We diagnosed the patient with acute occlusion of the PSA due to COVID-19. The complicated disease was successfully treated using distal artery bypass.

We report a case of a 68-year-old female patient with an 8-mm right gastric artery aneurysm. The attempt at endovascular treatment was unsuccessful and therefore the patient underwent laparoscopic surgery for the resection of the unruptured right gastric artery aneurysm. The postoperative course was uneventful, and the patient is currently under observation as an outpatient. Although endovascular treatment is the first choice for treatment of unruptured right gastric aneurysms, laparoscopic surgery offers advantages such as less invasiveness, anatomical accessibility, and the ability to perform histopathological examination, making it an effective treatment option when endovascular treatment is difficult.

Intravenous leiomyomatosis (IVL) remains scarcely reported, and complete tumor resection is the recommended treatment. Herein, we present a comprehensive review of the case of a 52-year-old woman who suffered from recurrent syncope episodes due to IVL with intracardiac extension to the right atrium. Partial tumor resection and postoperative hormone therapy were conducted first. However, the 6-month postoperative follow-up computed tomography scan revealed a tendency for the IVL to increase in size, and complete resection was conducted. In this article, we would like to emphasize that partial resection followed by hormone therapy is insufficient for IVL, and complete resection should be chosen.

Cold agglutinin disease (CAD) is a rare and autoimmune hemolytic disorder caused by the presence of cold-reacting autoantibodies against red blood cells. An abdominal aortic aneurysm (AAA) is a potentially life-threatening condition. This report describes an 83-year-old man with AAA who was diagnosed with primary CAD 9 years before undergoing AAA surgery. The patient underwent successful endovascular aortic repair. Temporary hemolytic anemia and exacerbation of jaundice were observed postoperatively despite strict temperature control. Red blood cell and haptoglobin transfusions may prevent fatal hemolytic anemia, renal disorders, embolism, and systemic complications.