Background: Thrombosis is known as one of complications after long-term central venous catheter (CVC) positioning. Objectives: The purpose of this study is to assess the incidence and risk factors of thrombosis after CVC positioning. Patients and methods: Broviac catheters were inserted into external jugular or subclavian veins in 78 children under general anesthesia, and into subclavian or femoral veins in 45 adults under local anesthesia for the last 5 years. Results: Over the observation period (from 3 months to 40 months), CVC-related venous thrombosis episodes were occurred in 4 children and 3 adults. The incidence of CVC-related thrombosis was 5.1% in children and 6.7 % in adults. There was no significant difference between children and adults in the incidence of CVC-related thrombosis. The incidence of CVC-related thrombosis was 3.1% when the catheters of 6.6Fr and under were placed, meanwhile it was significant higher (14.8%) when catheters of 7Fr and up. Conclusion: The size of CVC appears to be an important factor to prevent a CVC-related thrombosis. A smaller catheter should be inserted when it will be placed for a long period of time.

Two-years has passed since the Japanese Guideline for Prevention of Venous Thromboembolism (VTE)was published. It must be revised according to the latest clinical evidences in Japan. We therefore conducted a survey on the present status and clinical outcome of prevention of VTE in patients elected to undergo digestive organ surgery in our department. Deep venous thrombosis (DVT) was screened by the clinical symptoms and the difference in the leg diameter between left and right or between before and after surgery, and diagnosed by duplex scan. Pulmonary thromboembolism (PTE) was screened by the clinical symptoms and decrease of oxygen saturation of peripheral arterial blood, and diagnosed by perfusion lung scintigraphy or chest multi-slice helical CT. Five hundred patients have been surveyed (316 males and 164 females; the mean age, 63.3±11.4years). 12 patients (2.4%) had past history of VTE and two patients had active DVT. Four-hundred and forty-nine patients (89.8%) had several risk factors, and 159 patients (31.8%) had risk factors more than four. Four-hundred and fifty-two patients (90.4%) were categorized into the highest/high-risk group. Prophylactic measures were properly carried out according to the Guideline in 98% of patients. Even if patients were in the highest/high-risk group, low dose unfractionated heparin was used only in 13 patients (2.9%).Symptomatic DVT was not found, 1 patient (0.2%) was diagnosed as symptomatic PTE, and no patient died of VTE. Because of the small number of symptomatic VTE, we could not evaluate the risk factors. Future analysis of risk factors for VTE is needed after further patient accumulation.

Internal valvuloplasty for a deep vein with additional procedures (high ligation and stripping of saphenous vein etc.) were performed in 33 limbs of 31 patients with chronic venous insufficiency between February 1997 and February 2006. Air plethysmography was used to evaluate venous function since 2000. Recurrence of a leg ulcer was found in one case out of eight at the 15th postoperative month. The ulcer-recurrence-free survival rate was 100% at 1 year and 85.7 % at 2 years postoperatively. One patient underwent reoperation 3 years after valvuloplasty because of bleeding from lipodermatosclerotic skin. All patients showed the improved symptoms as early results. Reflux of the femoral vein by descending venography improved from grade 3.3 to 1.4 after surgery. The venous filling index by air plethysmography was also improved from 7.5 ml/sec to 4.7 ml/sec. Identification of a target valve is an important technical aspect of valvuloplasty. Prevention of venous leaflet injury by meticulous attention was also important during venotomy. Deep vein thrombosis occurred in two cases postoperatively. (Conclusions) Internal valvuloplasty with additional procedures was an effective option for chronic venous insufficiency under strict indications. However, care must be taken to avoid postoperative deep vein thrombosis by antithrombotic therapy such as oral warfarin for one month after surgery.

We performed percutaneous transluminal angioplasty (PTA) for subclavian vein stenosis due to arterio-venous fistula (AVF) to preserve the blood access. The objective of this study was to evaluate whether PTA for subclavian vein of AVF was relevant in terms of the long-term patency rates compared to those by PTA for AVF. We defined the primary patency period from the first PTA to re-PTA and first surgical treatment for the AVF, and the secondary patency period from the first PTA to ligation of fistula as giving up angioplasty. After the first PTA , thirty-five cases of chronic hemodialysis including 10 diabetic cases were observed for 1 to 94 months (ave. 24 months). The cumulative primary patency rates were 78.0%, 67.9%, 52.4%, 42.8% and 30.6% at 3 months, 6 months, 1 year, 2 year and 3 year, respectively. The cumulative secondary patency rates were 97.1%, 90.4%, 79.2%, 74.5% and 67.7% at 3 months, 6 months, 1 year, 2 year and 3 year, respectively. Diabetic cases showed significantly lower secondary patency rates than non-diabetic cases (P=0.015). The results of our patency rates were close to that of forearm vein PTA for AVF. We concluded that PTA for subclavian venous stenosis due to AVF was a safe and effective procedure on chronic hemodialysis patients.

The limb circumference was measured with time by a three-dimentional measurement system in young female volunteers, and the effects of elastic stockings, leg exercise and limb elevation on edema prevention were studied The leg edema increased gradually from morning to the evening, indicating the importance of edema prevention since morning. Elastic stockings, even with a pressure as low as 8mmHg, were effective on edema prevention. Although leg exercise and limb elevation were also useful for preventing and reducing the leg edema, strong exercise might be necessary to get enough effects.

Coronary artery bypass grafting (CABG) is the most common procedure for adult cardiovascular surgery. Saphenous vein graft (SVG) is used as one of the conduits for CABG. Endoscopic saphenous vein harvest (ESVH) through small incision, could decrease wound complication, and give operation satisfaction for patients. Wound complications were observed, hematoma (1.6%), and lymphorrhea (0.8%), while no wound infection.

Post operative angiography, in our institution, the patency rate of SVG harvested by ESVH (90.0%) was as good as the other reports. And, there was no statistically difference between the endoscopic and traditional open harvest groups (90.0% vs 91.8%) in our experience.

ESVH is less invasive technique for CABG, and cosmetical benefit for patients with same patency.

Soleus venous aneurysms are rare, but a life-threatening lesion as one of sorce of pulmonary embolisms. A 53-year-old woman was admitted by ambulance with a acute dyspnea on awakening. On admission, she was in shock state with tachypnea and hypoxemia, and diagnosed as pulmonary embolism by CT scanning and pulmonary scintigraphy. Thrombi in a pulmonary artery disappeared by thrombolytic therapy and warfarin, and the clinical symptom was approved. However ascending venography and duplex scanning showed a soleus venous aneurysm with intraluminal thrombus, which appeared to a cause of the pulmonary embolism.

After prophylactic placement of IVC filter, surgical resection of soleus venous aneurysm was performed. Wearing of elastic compression stockings and anticoagulation therapy by warfarin were continued, and an good postoperative outcome was obtained without a recurrence.