CD34 is a cell surface marker, which is expressed in various somatic stem/progenitor cells such as bone marrow (BM)-derived hematopoietic stem cells and endothelial progenitor cells (EPCs), skeletal muscle satellite cells, epithelial hair follicle stem cells, and adipose tissue mesenchymal stem cells. CD34+ cells in BM and peripheral blood are known as a rich source of EPCs. Thus, vascular regeneration therapy using granulocyte colony stimulating factor (G-CSF) mobilized- or BM CD34+ cells has been carried out in patients with various vascular diseases such as chronic severe lower limb ischemia, acute myocardial infarction, refractory angina, ischemic cardiomyopathy, and dilated cardiomyopathy as well as ischemic stroke. Pilot and randomized clinical trials demonstrated the safety, feasibility, and effectiveness of the CD34+ cell therapy in peripheral arterial, cardiovascular, and cerebrovascular diseases. This review provides an overview of the preclinical and clinical reports of CD34+ cell therapy for vascular regeneration.

Vascular surgery trainees often do not get to perform carotid endarterectomy (CEA) directly on the patients as it requires meticulous surgical technique and has a high risk of procedure-related complications. Hence, the role of simulation in training future vascular surgeons becomes essential. This review aims to assess the types and utility of simulators available for CEA. In this systematic review, all the studies performed on CEA simulation were included. The purpose of this review was to assess different types of simulators and their usefulness for CEA. We identified 122 articles, of which 10 were eligible for review. A variety of simulators, ranging from animal models, virtual reality simulators and commercially designed models with high fidelity options were used. Technical competence was the major domain assessed in the majority of the studies (n=8), whereas four studies evaluated anatomical and procedural knowledge. Blinding was done in five studies for assessment purposes. The majority of studies (n=9) found the simulation to be an effective tool for achieving technical competence. This review shows the potential usefulness of simulation in acquiring technical skills and procedural acumen for CEA. The available literature is unfortunately too diverse to have a common recommendation.

Computational fluid dynamics analysis of the growth process of saccular abdominal aortic aneurysm was performed. A 3D model of aortic aneurysm was created based on CT images. Properties in terms of wall shear stress, mean flow velocity, mean pressure, energy loss, and pressure loss coefficient were calculated using thermal fluid analysis software “ANSYS CFX.” As the aneurysm expanded, the mean flow velocity decreased and the wall shear stress, mean pressure, energy loss, and pressure loss coefficient increased. Wall shear stress increased when the aneurysm was small, suggesting that is related to the development and growth of the aneurysm. (This is secondary publication from J Jpn Coll Angiol 2021; 61: 3–10.)

Background and Purpose: There are many cases of cerebral infarction of unknown etiology in which the embolic sources cannot be identified including atrial fibrillation despite achievement of complete revascularization after thrombectomy.

Method: An analysis was conducted for 556 consecutive cases of patients who were hospitalized for cerebral infarction to determine the significance of accurate classification of disease type and investigation into causes of cerebral infarction of unknown cause.

Result: According to the Trials of Org 10172 in Acute Stroke Treatment (TOAST) classification, cerebral infarction of other/unknown etiology was observed in 94 cases, of which 22 cases were found to have causes by additional workup. Implantable cardiac monitors were inserted in 15 of 76 cases of cryptogenic cerebral infarction, of which 4 cases (26%) showed detection of paroxysmal atrial fibrillation (PAF) during observation period (223–384 days).

Conclusion: Brain natriuretic peptide (BNP) measurement, abdomen-pelvic computed tomography (CT), cardiac monitoring for 1 week, and implantable cardiac monitors (ICM) were useful for the classification of disease type and detection of cryptogenic atrial fibrillation. (This is secondary publication from J Jpn Coll Angiol 2021; 61: 49–55.)

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.)

Objective: Arteriovenous graft (AVG) infection influences the survival and quality of life of patients, causing life-threatening sepsis reducing dialysis access. This study aimed to evaluate an appropriate treatment strategy for AVG infection.

Methods: We analyzed 61 cases involving AVG infections identified at a single center. The cases were divided into two groups based on the type of AVG and surgical methods, namely, currently used AVG (cAVG) (n=29) or abandoned AVG (aAVG) (n=32) and total graft excision (TGE) (n=10) or partial graft excision (PGE) (n=46).

Results: There was a significant difference in lower procedure frequency (p<0.001) and longer procedure time (p=0.014) in the cAVG group. A significant difference in lower reinfection rate (p=0.009) was found in the TGE group. Multivariable analysis confirmed that aAVG significantly independently affected the reinfection rate (hazard ratio, 2.208; 95% confidence interval, 1.069–4.561; p=0.032). Staphylococcus aureus was the most frequent cause of AVG infection (61.5%); 77.5% of Staphylococcus aureus were methicillin-resistant Staphylococcus aureus.

Conclusion: We found a higher risk of reinfection after PGE than TGE, and aAVG infection was associated with approximately two times higher likelihood of reinfection. These findings suggest that TGE should be considered for patients with AVG infections, particularly aAVG infections.

Objective: To develop and validate a task-specific rating scale (TSRS) by comparing with the Global Rating Scale (GRS) for the evaluation of brachial artery embolectomy (BAE).

Methods: Participants were divided into expert and novice groups who were oriented on the locally developed simulator model. The following day, an embolectomy procedure was performed independently by the participants and graded by two independent assessors using the GRS and TSRS. Validity was evaluated using Pearson’s correlation coefficient (r), reliability by the interclass correlation coefficient (ICC), and agreement by Bland–Altman plots. A p-value <0.05 was considered significant.

Results: Thirty-two participants were enrolled in this study. The overall TSRS was found to be a valid assessment tool (r=0.82; 95% confidence interval [CI]: 0.66, 0.91; p<0.001). Domain-specific analyses showed a moderate positive association between all domains (p<0.05), except for instrument handling (r=0.09; 95%CI: −0.27, 0.42; p=0.642). The ICC for overall scores showed excellent reliability for both instruments, GRS and TSRS, with values of 0.97 and 0.92, respectively.

Conclusion: The TSRS was found to be a valid and reliable assessment tool for BAE; however, for some domains, such as instrument handling and time and motion, it has limited reliability.

Objective: Total aortic arch replacement (TAR), particularly in individuals with extensive atherosclerotic alterations, especially shaggy aortas, is more crucial and difficult. The objective of this retrospective investigation was to ascertain if patients with shaggy aortas would respond to modified isolated cerebral perfusion (ICP).

Materials and Methods: Between 2015 and 2020, nine individuals with shaggy aortas who received treatment for arch aneurysms were examined. Four and five patients, respectively, who had arch replacement with traditional selective cerebral perfusion (SCP) and modified ICP, were evaluated, and their short- and long-term results were compared.

Results: There were no appreciable variations in the postoperative results between patients with traditional SCP and those with modified ICP. Following surgery, one patient developed paraparesis, while two individuals with traditional SCP experienced persistent neurological damage. In patients with modified ICP, there were no postoperative neurological or other problems associated to atherosclerosis; nevertheless, one patient experienced stroke 5 months after surgery.

Conclusion: Patients with shaggy aorta may not receive enough brain protection from TAR with standard SCP because single axillary artery perfusion can result in nonphysiological flow and atheroma separation. Even in patients with shaggy aortas, TAR with modified ICP is safe, but late-phase severe adverse cerebrovascular events should be taken into account.

Objective: The objective of this study was to use a portable laser Doppler flowmeter (LDF) to measure the toe blood flow and pulse amplitude as a screening test for peripheral arterial disease (PAD) in dialysis patients and compare the diagnostic abilities of the aforementioned parameters measured using an LDF with those of the ankle-brachial index (ABI) and toe brachial index (TBI).

Methods: The 14 patients in this retrospective study received maintenance hemodialysis (HD). We measured the blood flow and pulse amplitude on the ventral side of the first toe with a portable LDF while the patients were undergoing an HD session. The correlations between the blood flow/pulse amplitude in the toe and the ABI/TBI were examined.

Results: Both the ABI and TBI had a strong correlation with pulse amplitude. The sensitivity and specificity of the pulse amplitude measured with the LDF for detecting PAD in HD patients as determined by a receiver operating characteristic curve analysis were 1.00 and 0.88, respectively.

Conclusion: Measuring the pulse amplitude in the toe with a portable LDF may serve as a simple and useful screening test for PAD in HD patients.

Objectives: This study aims to discuss the midterm results of thoracic endovascular aortic repair (TEVAR) with reentry closure for chronic type B aortic dissection (CTBAD).

Materials and Methods: This retrospective study analyzed 13 patients with CTBAD who underwent TEVAR with reentry closure between July 2014 and December 2020. We evaluated the false lumen (FL) cross-sectional area using computed tomography images of the descending aorta at the level of the bronchial bifurcation, Valsalva sinus, celiac artery, and infrarenal abdominal aorta pre- and postoperation. The study endpoints were technical and clinical success rates, freedom from additional aortic reintervention or surgery, and survival.

Results: Technical success was obtained in 12 patients (92.3%) with no hospital mortality and neurological complications. The postoperative observation period was 49.2±21.5 months. The clinical success rate was 76.9% (10 cases), and a postoperative reduction of the FL cross-sectional area was obtained in 53.8% of patients. The 5-year overall survival rate was 64.8% with no aortic-related deaths while the 5-year freedom from additional aortic surgery rate was 66.7%.

Conclusions: TEVAR with reentry closure suggests preventing FL dilatation or rupture in CTBAD, but the revision of our devices and further research with more patients and longer follow-up periods are required.

Objectives: Pregnancy-associated deep vein thrombosis (DVT) is a rare disease, and data on anticoagulation therapy are lacking. The present study examined the treatment outcome with unfractionated heparin (UFH) subcutaneous injection in patients with pregnancy-associated DVT.

Methods: This single-center, retrospective, observational study enrolled 15 patients with pregnancy-associated DVT treated from January 2014 to April 2021.

Results: The median age was 35 years. The median gestation week at onset was 10 (interquartile range is 8–11). All patients presented with painful symptoms with edema. All patients had proximal DVT. Anticoagulation therapy using UFH was performed in 14 patients. The median continuous dose of heparin was 18,750 U/day, and the median subcutaneous dose was 20,000 U/day. During the outpatient period, the values of activated partial thromboplastin time fluctuated wildly, but the fibrin monomer complex level remained consistently low. There were two mild bleeding complications, but neither prevented the continuation of anticoagulation therapy. During delivery, thrombi were not detected in 10 of 13 patients (77%), whereas three patients (23%) exhibited regression without resolution of the thrombus.

Conclusion: Anticoagulation using UFH subcutaneous injection was safely performed in patients with pregnancy-associated DVT without serious complications or progression of thrombosis.

Secondary aortoenteric fistula (sAEF) is a rare but serious complication after open aortic aneurysm repair (OAR). Although there is no consensus on the treatment strategy for sAEF, acute management of bleeding and infection control greatly affect the outcome. We report five cases of sAEF following OAR from 2016 to 2021. One patient died of sepsis following graft infection, whereas the others had relatively good outcomes. No recurrence of infection or fistula has been observed over an average follow-up period of 29.8 months. Timely management of bleeding and infection with surgical intervention resulted in favorable outcomes in our patients.

We report a case of a deep femoral artery aneurysm with a ligated proximal artery that was successfully managed with endovascular therapy. An 84-year-old male was referred to our institute with a history of surgical resection of a left ruptured deep femoral artery aneurysm wherein another aneurysm was found on the peripheral side. Proximal artery ligation of the peripheral lesion was performed. The residual aneurysm had gradually enlarged after surgery, and contrast-enhanced computed tomography showed contrast effects in the aneurysm that extended to the distal artery. The aneurysm was successfully treated by direct percutaneous puncture embolization with N-butyl-cyanoacrylate.

A 78-year-old man presented with severe stage 3 (Fontaine IV, Rutherford 5, W1 I3 FI0) right limb ischemia. Although his artery was completely occluded from below the right external iliac to the popliteal artery, collateral circulation from the right lateral femoral circumflex artery was well developed and supplied the lower extremity arteries. We selected an uncommon crossover bypass strategy with the left common femoral artery to the right lateral femoral circumflex artery to improve lower extremity perfusion via indirect revascularization. Bypass using the lateral femoral circumflex artery as an outflow is an option for patients with major lower extremity artery occlusions.

A 78-year-old man complaining of left leg swelling was diagnosed with an abdominal aortic aneurysm with an irregular margin. A four-dimensional computed tomography (CT) showed an aortoiliac vein fistula. An AFX stent graft was urgently implanted, and a Viabahn VBX was inserted into the left iliac vein. The aneurysmal sac was embolized. After the procedure, enhanced CT confirmed a patent stent graft without any endoleak or fistula. The patient was discharged ambulatory. An aortoiliac vein fistula is a differential diagnosis for leg edema, and a four-dimensional CT is beneficial in diagnosing the condition.

Congenital abdominal aortic aneurysm (AAA) with coarctation has been considered an extremely rare condition. In this study, we present a 3-year-old boy, who was diagnosed by chance with congenital AAA at first operation. We replaced the AAA+coarctation with a 6-mm polytetrafluoroethylene (PTFE) graft. Histological examination of the aortic wall revealed no particular abnormalities. Collateral vessels were noted to develop over 14 years of followup. Good blood flow to both lower limbs and no intermittent claudication were observed. After growth, at the age 17, he underwent extra-anatomical bypass using a 12-mm PTFE graft. This is the first report of successful treatment of congenital AAA+coarctation with longterm followup.

A 72-year-old man, who was treated 10 years earlier with endovascular aortic aneurysm repair, presented with a fever. Considering the concern of stent graft infection, the patient was treated with antibiotics, but his condition did not improve. He underwent stent graft resection and reconstruction with a Dacron graft. Pathological analysis of the aortic wall and computed tomography revealed recurrent intimal sarcoma, and the patient underwent resurgery. During follow-up, he underwent two additional resections for local recurrence, but he died 17 months later. Our results suggest that intimal sarcoma should be considered during the follow-up after endovascular aortic aneurysm repair.

In this study, we present the case of a 21-year-old woman with pseudocoarctation of the aorta with saccular aneurysms that were evaluated by four-dimensional flow magnetic resonance imaging and histological analysis. We observed complete occupation of the aneurysm sacs by vortex flow and high peak wall shear stress in the proximal region of the kinked aorta. The aortic replacement was performed for the thoracic aortic aneurysms and the clinical course was uneventful. The aneurysms were histopathologically diagnosed as pseudoaneurysms based on the disappearance of all three layers and their replacement with collagen-rich connective tissues. These findings indicate that abnormal flow dynamics and the resulting abnormal shear stress in the aorta may play central roles in the formation and development of a saccular aneurysm.

We report a case of a 77-year-old woman with massive pulmonary embolism associated with heparin-induced thrombocytopenia. Before developing a pulmonary embolism, the patient underwent gastrectomy due to gastric cancer and received subcutaneous heparin calcium for deep venous thrombosis prophylaxis for 5 d. Then, thrombectomy with cardiopulmonary bypass using full heparinization was successfully performed. The patient was definitively diagnosed with this condition postoperatively, based on elevated serum antibody levels, in addition to pre- and postoperative thrombocytopenia and thrombosis. Intravenous heparin therapy was switched to argatroban. Although it is uncommon, clinicians should consider this condition in patients with a history of heparin exposure.