Coronavirus disease 2019 (COVID-19) has become a huge threat worldwide as a pandemic, which could also cause venous thromboembolism (VTE), including pulmonary embolism (PE). On the basis of the concept of the high risk for VTE in patients with COVID-19, some studies reported the potential benefit of anticoagulation for the primary prevention of VTE. However, optimal strategies for the prevention of VTE in COVID-19 still remain unknown. Additionally, ethnic differences may have notable implications in the presentation of VTE. Very recently, in the Japanese Society of Phlebology and Japanese Society of Pulmonary Embolism Research, a questionnaire surveillance for COVID-19 and VTE was conducted, which revealed that the vast majority of the institutions did not have specific recommendations for the prevention of VTE with anticoagulation, the incidence rate of VTE was 0.6% (7/1243), and that of PE was 0.4% (5/1243). The current questionnaire surveillance has suggested that the management strategies for the prevention of VTE by anticoagulation in COVID-19 could widely vary according to institutions, and the number of patients diagnosed as VTE in COVID-19 in Japan was quite small compared with reports from other countries. Further studies, including cohort/registry-based studies, are warranted to confirm these results.

Objective: To review the outcomes of catheter-directed thrombolysis (CDT) for salvage of thrombosed arteriovenous fistula (AVF) in a single centre in Southeast Asia.

Methods: A retrospective study of CDT in AVF between January 2015 and July 2018 at a tertiary university hospital was carried out.

Results: Within the study period, 85 patients underwent CDT for AVF thrombosis. Of these patients, 78% underwent CDT for 24 h and 12% required CDT for 48 h. Moreover, 14% of patients had bleeding during CDT and hence required a decrease in dosing or complete cessation. Incidence of intracranial haemorrhage was 1%, and technical success was 92%. Post CDT, primary patency rates at 12, 24 and 36 months were 87%, 62% and 36%, respectively; assisted primary patency rates at 12, 24 and 36 months were 96%, 82% and 69%, respectively; and secondary patency rates at 12, 24 and 36 months were 99%, 93% and 86%, respectively. Multivariate analysis did not identify any predictive factors for patency post CDT.

Conclusion: Within our study population, CDT for AVF salvage conferred good technical results with low rates of complications. There was good primary patency at 12 months, and the results were sustained up to 36 months. It remains a useful modality for fistula salvage, avoiding surgical intervention.

Objective: To find a new predictor of endoleak (EL) and aneurysm sac expansion after endovascular aneurysm repair (EVAR), we evaluated the platelet count recovery (PCR) process after EVAR.

Materials and Methods: Two hundred five patients treated with elective EVAR from 2007 to 2015 were retrospectively analyzed. We compared the platelet count ratio until postoperative day (POD) 7 to the presurgical baseline between patients with and without persistent EL (≥ 6 months). Subsequently, we calculated the optimal platelet count ratio for distinguishing persistent EL using receiver-operating characteristics analysis. A platelet count ratio on POD7 ≥118% was defined as the PCR. We evaluated the PCR’s influence on the cumulative aneurysm sac expansion rate.

Results: The average platelet count ratio on POD7 rose above baseline (112%), and the ratio was attenuated by persistent EL (103%). Of 205 patients, 126 (61%) were assigned to the disturbed PCR group (PCR(−) group). Cumulative aneurysm sac expansion rate was higher in the PCR(−) group than the PCR(+) group (34.4% vs. 12.8% in 5 years, p=0.01).

Conclusion: Disturbed PCR after EVAR may be associated with ELs and eventual aneurysm sac expansion.

Objective: Refractory type 1a endoleak after endovascular aneurysm repair (EVAR) can pose a significant challenge to surgeons and interventional radiologists. Continuous sac expansion results in aneurysm rupture and mortality. In such circumstances, an external infrarenal aortic wrap could serve as an essential and alternative solution.

Methods: We assessed the application of an infrarenal aortic neck wrap for the treatment of refractory type 1a endoleak in n=6 consecutive patients along with the introduction of a novel assessment technique in order to assure their intraoperative success with no radiation exposure and contrast use.

Results: The median sac expansion was 8.5 mm (interquartile range [IQR], 5–20 mm). The median neck diameter and length of the aortic neck were 23 mm (IQR, 18–25 mm) and 21 mm (IQR, 18–25 mm), respectively. The median length of follow-up post wrap is 24 months (IQR, 14–34 months). There was no associated mortality or morbidity and requirement for any further interventions.

Conclusion: The study demonstrates that aortic wrapping for the treatment of refractory type 1a endoleak for any given neck diameter and length is safe, effective, and long lasting. The suggested novel intraoperative assessment technique contributes to the safety of the procedure by diminishing the need for intraoperative radiation exposure, contrast, and shorter operative time.

Objective: To determine the prognostic value of regional tissue oxygenation saturation (rSO₂) for ulcer healing after endovascular treatment (EVT) of peripheral arterial disease (PAD).

Materials and Methods: Among PAD patients, 34 patients with chronic limb-threatening ischemia underwent EVT for limb salvage. We retrospectively analyzed the cutoff rSO₂ values on postoperative day 1 to predict ulcer healing and patient prognosis. Skin perfusion pressure (SPP) and transcutaneous oxygen pressure (TcPO₂) were also used to assess wound healing.

Results: A finger-mounted tissue oximeter can easily measure rSO₂ on the dorsal foot. Among the 34 patients, the ulcer healed in 25, and no changes were observed in 2 patients at 1 month after EVT. However, 7 patients needed major amputation at the same time. Wound healing was achieved in all patients with rSO₂≥50%. With this cutoff, the sensitivity and specificity of the new device for wound healing were 100% and 64%, respectively. In all the wound healing cases, SPP was ≥45 mmHg, and TcPO₂ was ≥40 mmHg.

Conclusion: To assess limb ischemia, rSO₂ can be measured quickly and easily using this device. We suggest that an rSO₂>50% shows good prognosis for ulcer healing.

Objective: The correlation between lipoproteins and arterial thrombosis is not fully elucidated, and no data exist in terms of lipoprotein profiles before heparin administration in patients with coronary arterial thrombosis (CAT). This cross-sectional study aimed to evaluate the lipoprotein profile before heparin administration in 63 ST-segment elevation myocardial infarction (STEMI) patients with CAT.

Methods: The lipoprotein profile was measured via polyacrylamide gel electrophoresis prior to heparin administration for primary percutaneous coronary intervention for STEMI. Age- and sex-matched subjects with <25% stenosis in stable coronary artery disease were enrolled as controls.

Results: In the pre-heparin serum, the fraction of very-low-density lipoprotein (P=0.75) in STEMI patients was not different from that in controls, and the fraction of intermediate-density lipoprotein (P<0.01) in STEMI patients was significantly lower than that in controls. Although the fraction of small dense low-density lipoprotein (s-LDL) in STEMI patients was significantly higher than that in controls (P<0.01), 44% (28/63) of STEMI patients were negative for s-LDL.

Conclusion: Although lipoproteins are a risk factor for atherosclerosis, lipoprotein profiles with CAT following atherosclerosis in STEMI are different from those profiles without CAT in stable coronary artery disease.

Objective: We selectively place carotid shunting when ipsilateral mean stump pressure is less than 40 mmHg during carotid endarterectomy (CEA). This study aimed to assess the validity of our selective shunting criterion by 1D-0D hemodynamic simulation technology.

Materials and Methods: We retrospectively reviewed 88 patients (95 cases) of CEA and divided them into two groups based on the degree of contralateral internal carotid artery (ICA) stenosis ratio, which was determined as severe when the peak systolic velocity ratio of the ICA to the common carotid artery was ≥4 by carotid duplex ultrasonography. Patients with severe stenosis or occlusion in contralateral ICA were classified as hypoperfusion group, and those without such contralateral ICA obstruction were classified as control group.

Results: Perioperatively, the mean carotid stump pressures were 33 mmHg in hypoperfusion group and 46 mmHg in the control group (P=0.006). We simulated changes in carotid stump pressure according to the changes in the contralateral ICA stenosis ratio. 1D-0D simulation indicated a sharp decline in carotid stump pressure when the contralateral stenosis ratio was >50%, while peripheral pressure of the middle cerebral arteries declined sharply at a ≥70% contralateral stenosis ratio. At this ratio, the direction of the ipsilateral cerebral arterial flow became inverted, the carotid stump pressure became dependent on the basilar artery circulation, and the ipsilateral middle cerebral artery became hypoperfused.

Conclusion: Our clinical and computer-simulated results confirmed the validation of our carotid shunting criterion and suggested that contralateral ICA stenosis ratio over 70% is a safe indication of selective shunting during CEA.

Objective: Venous leg ulcers (VLUs) caused by chronic venous insufficiency are difficult to treat. Outcomes after compression therapy and the current standard of care often used in conjunction with other options vary widely. We examined the effects of foam inserts on sub-bandage pressures in patients with VLUs and compared use of foam inserts in elastic and inelastic compression bandaging.

Methods: Six patients (≥20 years old) with VLUs and skin perfusion pressure >40 mmHg were included. Each patient underwent weekly treatment regimens of debridement, dressing changes, and dual sponge-insert application followed by elastic (n=3) or inelastic (n=3) compression bandaging. The median resting sub-bandage pressures of the ulcer beds, wound sizes, and healing percentages were recorded. Wound beds were biopsied before and after treatment for histological assessment. Nine healthy volunteers served as controls during preliminary testing.

Results: With proper sub-bandage pressures (>35 mmHg), the average healing time was 88.0±66 days, which was shorter than anticipated (i.e., ≥6 months). Combining large and local sponge-foam inserts increased sub-bandage pressures regardless of the compression bandage selected, with marked improvements seen in deeper wounds.

Conclusion: Layering one or two sponge-foam inserts beneath compression bandages facilitates uniform and optimal wound-bed pressure, which accelerates the healing of VLUs.

A 78-year-old man presented with an abdominal aortic aneurysm (AAA) and a horseshoe kidney coexisting with accessory renal arteries. We performed surgical treatment with endovascular aneurysm repair, sacrificing the accessory renal arteries. We used an aortic cuff to prevent a type II endoleak from the inferior mesenteric and accessory renal arteries. Decreased renal function was transient, and postoperative computed tomography showed no endoleak. This case report supports the feasibility of endovascular surgery for treating AAA in patients with a horseshoe kidney.

Isolated internal iliac artery aneurysms are rare, and there are no reports of human immunodeficiency virus (HIV)-related vasculitis in Japan. We report our experience with a 51-year-old man diagnosed with acquired immunodeficiency syndrome, discovered during the postoperative course when the patient exhibited remittent fever and susceptibility to infection after emergency interventional radiology therapy for a right isolated internal iliac artery aneurysm. The patient had positive treponema pallidum particle agglutination test result before admission, and tests for sexually transmitted disease showed positive results for HIV H-1 antibodies. The repeated fevers were attributed to HIV infection-related susceptibility.

Surgical indication and treatment for patients with Kommerell diverticulum and aberrant subclavian artery are still not well established. A patient with esophageal and tracheal compression resulting from these anatomical abnormalities was successfully treated with a hybrid approach of total arch replacement, frozen elephant trunk technique, aberrant left subclavian artery transection, and left subclavian artery reconstruction through median sternotomy. Compressive symptoms were relieved without resecting the enlarged diverticulum. In this case, the importance of preoperative investigation for the main cause of compressive symptoms is illustrated and a novel treatment strategy is outlined.

In the first case, a 60-year-old man was referred to our hospital for a sudden stomachache. A computed tomography scan revealed a thrombus at ascending aorta with acute mesenteric ischemia. In the second case, a 62-year old man developed a hypoglycemic attack with unbalanced diet. A computed tomography showed a thrombus at ascending aorta without thromboembolism. Laboratory data of both cases showed elevated platelet and a loss of antithrombin III. We administered a resection of thrombus to prevent a systemic embolism. We suggested that the risk of ascending aorta thrombus was elevated platelet and a loss of antithrombin III.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common congenital kidney disease. However, reports on occasional cases of aortic dissection in PKD familial patients remain scarce. Herein, we describe rare aortic dissection cases in PKD familial patients (i.e., mother and daughter) and our successful treatment experience. The mother (84 years old) and daughter (53 years old) had a referral to us to treat type A acute aortic dissection. We performed emergency surgery and successfully treated the patients with an artificial graft. For comprehensive evaluation and treatment, ADPKD patients and their families should be screened for aortic diseases.

A 66-year-old Japanese male working at a stable developed abdominal pain and fever and was brought to the emergency department. The computed tomography scan revealed an aneurysm of approximately 70 mm in diameter, with an irregular border, at the infrarenal abdominal aorta. Emergency surgery was performed with a bifurcated Dacron graft. Streptococcus zooepidemicus was observed on the aneurysm wall. He was discharged in good condition and was prescribed oral amoxicillin/clavulanic acid for 4 months. He has remained well and did not develop inflammation. Evaluation of patient history and data, including the consumption of unpasteurized dairy food, occupation, and direct contact with animals, is important for an early diagnosis, a prompt surgery, and an appropriate antibiotic therapy.

A 66-year-old man presented with an enlarging abdominal aorta false lumen, after type A aortic dissection repair. Residual entries were located at the left renal artery, abdominal aorta, and left external iliac artery. The patient underwent endovascular aortic repair with left renal artery stenting to close the entries. Completion aortography showed no false lumen flow without an endoleak, and contrast-enhanced computed tomography 1 month after the procedure demonstrated complete false lumen thrombosis. A total endovascular approach is possible for abdominal aneurysmal dilation in chronic aortic dissection when all entries can be closed using a one-stage procedure with stent grafts and/or branch stenting.

A 68-year-old man with a history of superior mesenteric arterial thromboembolism due to chronic atrial fibrillation had experienced intermittent claudication (IC) of his left leg for 3 years. Computed tomography angiography showed focal occlusive lesions in the left distal popliteal artery and proximal segments of the infrapopliteal arteries. Endarterectomy was performed for these localized arterial lesions, and a drastic symptomatic improvement of IC after revascularization was achieved. The endarterectomized segments remained patent for 4 years after the surgery. Endarterectomy could be a useful alternative to bypass surgery and endovascular therapy for the treatment of localized infragenicular arterial lesions.

Type B aortic dissection (TBAD) is a rare but catastrophic complication of endovascular aneurysm repair (EVAR). We report two cases of TBAD occurring in the perioperative period of EVAR. The intraoperative and postoperative courses were unremarkable. Routine postoperative computed tomography angiography (CTA) revealed TBAD. Conservative treatment was successful, and no adverse aortic events occurred. TBAD that occurs in the perioperative period is likely to be iatrogenic in origin, uncomplicated, and managed with medical therapy: its prognosis is better than when the condition develops in the midterm postoperative period.

Nutcracker phenomenon (NCP) refers to left renal vein compression at the superior mesenteric artery origin involving hematuria and dysuria due to the compression of the renal venous return and pelvic congestion syndrome caused by the compression of the gonadal venous return. A leptosomatic woman (body mass index, 19 kg/m²) presented with NCP and Marfan syndrome accompanied by severe menorrhagia. Vascular ultrasonography revealed reversed flow in the left ovarian vein. Preoperative computed tomography revealed a sharp aortomesenteric angle and short aortomesenteric distance. After controlling her menstrual period via oral contraception, she underwent valve-sparing surgery for aortic root dilation, which spontaneously subsided the menorrhagia.