The Japanese guidelines for diagnosis, treatment and prevention of pulmonary thromboembolism and deep vein thrombosis, were published in 2004, and were revised twice for these 18 years. The treatments for venous thromboembolism (VTE) have been changed in Japan. Anticoagulant therapy is basic treatment and especially direct oral anticoagulants (DOAC) are now endorsed as first-line treatment. Edoxaban, rivaroxaban and apixaban are approved for VTE treatment in Japan and are direct factor Xa inhibitors. The 3 drugs have quick action, and can be administered with fixed doses without frequent laboratory monitoring. DOACs have drug-drug interactions mechanism that consists of P-glycoprotein transporter and CYP3A4-type cytochrome P450. Some DOACs affect the values of coagulation assays for the laboratory examination of inherited thrombophilia factors. The effects of DOACs are evaluated by prothrombin time and activated thromboplastin time in consideration of the dosing time. DOAC is not recommended in patients with VTE and with active gastrointestinal or genitourinary cancer because of a bleeding risk. DOAC should not be applied in patient with very high body weight, and is contraindicated in patient with VTE and antiphospholipid syndrome. It is important to learn some characteristics and special circumstances requiring careful consideration for DOAC when treating VTE.

As a surgeon for more than 40 years, the author has been involved in experimental and clinical research on revascularization materials from the vena cava to the arteries, and has gained the following recognition. 1) In general, woven artificial blood vessels are used for arterial reconstruction at the level of the aorta to the femoral artery, and functionally satisfactory results can be obtained. However, it is difficult to hope for its organization, and it is difficult to call it an ideal substitute blood vessel. 2) The autologous vein is the only small-diameter substitute that can withstand clinical use, especially in the lower extremities, where its application has reached the paramalleolar bypass, which seems to be the limit. 3) With the advent of a society with longevity, the development of small-diameter substitute vessels to replace autologous veins has become an urgent issue. The collaboration of nano-level technology, biotechnology and a community of quality knowledge will help develop small-diameter blood vessels that can withstand clinical use. 4) The author hopes that Japan’s unique medical office system will develop as a community of knowledge.

We investigated consecutive 3253 patients of varicose veins with incompetence of the great saphenous vein (GSV) and/or the small saphenous vein (SSV) to clarify the characteristics of SSV incompetence compared with GSV incompetence. There were 1070 male patients (age 15–91, median 64) and 2183 female patients (age 20–97, median 62). Doppler ultrasound was used to detect reverse flow in the saphenous veins caused by manual compression of the calf. For simplicity, we use the following abbreviation. “R”, “L”, “r” and “l” stand for the incompetence of the right GSV, the left GSV, the right SSV and the left SSV, respectively. For instance, “rl” stands for the incompetence of the bilateral SSV and “Lr” stands for the combination of the left GSV and the right SSV incompetence.

The follow-up period was up to 26 years, and 57 cases (median 9 years of observation period) showed valve failure in the saphenous vein at a different site from the initial diagnosis more than 5 years later. There were 16 cases of men (initial diagnosis age 45–81, median 61) and 41 women (initial diagnosis age 36–78, median 51). In 39 cases valve failure appeared in the GSV on the opposite side at the initial diagnosis (right→left 20, left→right 19). Eleven patients with valve failure only in the SSV at the initial diagnosis later appeared the GSV incompetence (the same side 3, the opposite side 8). On the other hand, seven patients with valve failure only in the GSV at the initial diagnosis later appeared the SSV incompetence (the same side 2, the opposite side 5).

Most of the patients were affected only one vessel (R=912, L=1020, r=135, l=155). Two vessels combination were RL=789, Lr=69, Rl=56, rl=40, Ll=25, Rr=13 from most to least. It is interesting that there were more contralateral combinations (Rl or Lr) than ipsilateral combinations (Rr or Ll). The incidence of bilateral SSV incompetence rl/(r+l+rl)=0.12 was less than that of bilateral GSV incompetence RL/(R+L+RL)=0.29. Three vessels combination (RLr=15, RLl=13, Lrl=5, Rrl=3) and four vessels combination (RLrl=3) were very rare.

Over all, 10% had SSV incompetence only and 6% had both SSV and GSV incompetence. Female/male ratio of SSV incompetence (257/73=3.52) was higher than that of GSV incompetence (1768/953=1.86). The left-sided predominance was more prominent in SSV (l/r=1.15) than in GSV (L/R=1.12). It is also more prominent in male (l/r=1.27, L/R=1.18) than in female (l/r=1.11, L/R=1.09). The incidence of congestive dermatitis (C4, C5 and C6 according to CEAP classification) in SSV incompetence (2.7%) was less than that in GSV incompetence (3.8%).

Direct oral anticoagulants (DOAC) are becoming more commonly used, and there is an increase in the use of doses other than those indicated for patients’ individual conditions. We have often selected low-dose edoxaban for a number of patients. From 2014 to 2019, we had 528 cases of venous thromboembolism. There were 105 patients with no oral anticoagulants, 249 patients with usual dose of DOAC, 98 patients with low-dose edoxaban, and 78 patients with warfarin. We examined the patient background and hemorrhagic/thrombotic adverse events of the low-dose edoxaban users. In 96 cases of low-dose edoxaban, 40 were proximal type, and 56 were calf type, 11 were symptomatic, and 85 were asymptomatic. The reason for using low-dose was the risk of bleeding in 48 cases and the prevention of thrombus propagation in 48 cases. In 3 of the 48 bleeding risk cases, anticoagulation was discontinued because of bleeding, and hemostasis was achieved promptly, which result in anticoagulation restart. Low-dose edoxaban is useful as an alternative to no anticoagulation or therapeutic dose of anticoagulants, and is an effective treatment option for patients at high risk of bleeding.

We report the case of a 94-year-old woman who underwent right femoral vein ligation under local anesthesia for treatment of a popliteal venous aneurysm (PVA) and pulmonary embolism (PE). She presented with mild respiratory distress and was diagnosed with acute PE secondary to a right PVA. Contrast-enhanced computed tomography and ultrasonography revealed a saccular-shaped venous aneurysm (diameter 26 mm) filled with thrombus. We performed right femoral vein ligation under local anesthesia to prevent recurrent PE. She received edoxaban for 3 months, which led to resolution of the pulmonary emboli. Shrinkage of PVA was confirmed, and the patient is in good health without lower extremity edema and recurrent PE, 24 months postoperatively. Recurrent PE is common in patients with PVA, who are treated only with anticoagulation therapy. Therefore, surgical treatment is recommended for PVA to prevent recurrent PE in the previous reports. Aneurysm resection concomitant with venoplasty or popliteal vein reconstruction is usually performed under general anesthesia. However, general anesthesia is invariably physically burdensome for elderly patients. Therefore, we performed femoral vein ligation under local anesthesia in this patient. It is important to maintain collateral blood flow through the great saphenous vein and deep femoral vein during femoral vein ligation. Femoral vein ligation may be considered in elderly patients in poor general health, who present with PVA.

Anterior cage dislodgement is a very rare complication of posterior lumbar interbody fusion, which causes severe vascular complications. Here, we report a successful cage removal operation. A patient underwent posterior spinal surgery, and the cage was dislodged anterior to the retroperitoneal space. Computed tomography showed inferior vena cava stenosis due to the cage dislocation. We performed a cage removal operation through median laparotomy. The inferior vena cava and both common iliac veins were taped to avoid fatal bleeding, and the cage was successfully removed. The patient had an uneventful postoperative period, and no complications were observed.

Case 1 was a woman in her seventies who underwent left leg varicose vein surgery 19 years ago. She presented to our department with sudden swelling of the left ankle and spouting hemorrhage while using the toilet. She was diagnosed using the CEAP classification C1,2r,4c,s, Ep, Asp, Pr, GSVb, GAV. Case 2 was a woman in her sixties who underwent right leg varicose vein surgery 14 years ago. She reported bleeding from the right epicondyle while taking a bath and visited our department the day after bleeding was stopped using a towel. She was diagnosed using the CEAP classification C1, 2r, 4a, c, s, Ep, Adp, Pr, POPV, CPV. Both patients were treated with foam sclerotherapy and recovered.Both patients presented with Grade 2 corona phlebectatica with insufficient perforating veins of lower legs, presumably because of increased venous pressure and venous dilatation caused by toilet or bathing leading to bleeding. Based on the above case findings, it is important to recognize that corona phlebectatica is an advanced form of venous disease.

Although ultrasonic Doppler technique is a mainstream method for identification and visualization of incompetent perforating veins, visualization is difficult in some patients. This report discusses the imaging protocol and advantages of four-dimensional CT using antegrade venography in the detection of incompetent perforating veins at our hospital. Four-dimensional CT was performed on four patients, and the incompetent perforating veins were visualized in all the patients. Regarding the patient for whom subfascial endoscopic perforator surgery was indicated, the presence of a thick perforating vein at the locus visualized by CT was confirmed. Four-dimensional CT using antegrade venography enables visualization of incompetent perforating veins and determination of the muscle compartments present. It is likely to be useful in detecting perforating veins that are difficult to visualize by ultrasonography, as well as for local diagnosis.