[Background and Aims] Blood coagulation in the dialysis circuit is one of the major problems in hemodialysis. Contact between air and blood is considered to contribute to activation of the coagulation system. Nikkisoʼs new dialysis circuit Arch Loop is expected to exhibit anticoagulant performance by reducing contact with air through an air-free chamber and a diaphragm pressure-monitoring system. We examined the effectiveness of Arch Loop in terms of anticoagulant performance compared with conventional dialysis circuits. [Method] Twelve outpatients on maintenance hemodialysis were enrolled in the study to investigate anticoagulant performance, measuring the activated clotting time (ACT) at 3 hours after the start of dialysis using Arch Loop or a conventional dialysis circuit, with a crossover design. [Results] ACT was significantly extended with Arch Loop compared with conventional circuits. (165.1±19.0 and 153.2±15.2 seconds, respectively, p＜0.002). [Conclusion] Arch Loop shows significant anticoagulant performance by reducing contact with air in the circuit. This performance of Arch Loop is still limited, and so further improvement is required prior to general use.

An 82-year-old male with a 2-year history of hemodialysis for end-stage renal disease due to diabetic kidney disease was admitted because of fever, epigastralgia, and chest and back pain that had persisted for two weeks. For a year prior to hospitalization, he had been treated with oral prednisolone because of pulmonary hemorrhage due to suspected vasculitis. On admission, laboratory findings showed marked elevation of inflammatory markers, and computed tomography revealed emphysematous cholecystitis, lower bile duct stones, and infected aortitis with a pseudoaneurysm in the thoracic aorta. Despite immediate antibacterial therapy, the patient developed septic shock. Therefore, endotoxin adsorption therapy using Polymyxin B Immobilized Fiber Column (Polymyxin B Immobilized Fiber Column direct hemoperfusion (PMX-DHP)) was administered for 2 days starting from day 2 after hospitalization. Even though Clostridium perfringens was detected in blood culture, adsorption therapy was effective for increasing the blood pressure. Endoscopic retrograde cholangiopancreatography was safely performed for bile duct drainage on day 16. However, enlargement of the pseudoaneurysm was subsequently confirmed. Therefore, endovascular repair with a stent graft was conducted on day 28. Consequently, the patientʼs general condition gradually improved, and he was discharged on the 77th hospital day. To our knowledge, it is commonly accepted that infection with Clostridium perfringens is associated with a therapy-resistant clinical course and poor prognosis for compromised hosts, like our case. The present case involved an elderly hemodialysis patient under steroid therapy, and so his clinical condition was impaired regarding infection control. However, we could achieve a favorite outcome, possibly attributable to the use of non-invasive and effective therapy comprising PMX-DHP and endovascular aortic repair in addition to drainage of the site of infection.

[Background] Radiation therapy is known to cause radiation arteritis or ureteral anastomotic failure due to adhesion or impaired blood flow. We performed a living renal transplantation for a recipient with a history of whole pelvic radiation therapy for an ovarian tumor 34 years prior to the surgery. [Case presentation] The recipient and donor passed the preoperative diagnosis successfully. Abdominal CT of the recipient showed no signs of calcification or strictures or vascular endothelial hyperplasia of the internal iliac artery or external iliac vein. The surgery was performed in 7 hours without vascular anastomotic problems. The first urine was noted 12 minutes after vascular anastomosis. The surgery was considered to have proceeded without complications. However, on post-operative day 11, ureteral anastomotic leak occurred. The recipientʼs serum examination showed creatinine elevation. Abdominal CT revealed liquid effusion around the transplanted kidney. An effusion drainage test showed a high level of creatinine elevation. The leak was successfully resolved without major complications by implanting a double J-stent in the transplanted ureter, a drainage tube around the transplanted kidney, and a urethral catheter. On post-operative day 30, the recipient was discharged from our hospital in a favorable condition. [Conclusion] Preoperative vascular assessment with CT was helpful in this case. Also, pressure reduction in the urinary tract may effectively prevent or cure ureteral anastomotic leak.

Previously, we reported that the Graft Covering Technique (GCT) yields good results as a method of blood flow control surgery for excessive blood flow in an arteriovenous fistula (AVF). It was performed for forearm AVF. This time, we applied GCT for excessive blood flow in upper arm AVF. A 70-year-old woman underwent GCT because of shunt vascular pain and excessive blood flow 3 years after superficialization of the brachial artery and placement of an internal shunt using the cephalic vein. The procedure consisted of closing the existing AVF, exfoliating the shunt vein, inserting that into the shortened vascular graft (covering), reconstructing AVF, and suturing the graft and anastomosis at several locations to fix it. After surgery, vascular pain disappeared and brachial blood flow decreased from 1910 to 1046 mL/min. Although reconstruction was performed at a proximal site, the shunt vein could be punctured for both blood withdrawal and blood return. GCT was considered to be useful for excessive blood flow in upper arm AVF.

In X-3 years, a woman in her 70s was started on hemodialysis. Her PT and APTT were 11 and 24 sec, respectively, at that time. Nafamostat mesylate had been used during dialysis as of October X-1, after she developed gastric antral vascular ectasia. She was treated with antimicrobial agents for fever and cough in February X, but did not improve. She was consequently admitted to our facility. Aside from pneumonia, abnormal coagulation was observed (PT：54 sec, APTT：215 sec). Coagulation factor V activity was significantly reduced, and factor V inhibitor and antiFV autoantibodies were detected in the blood, indicating the presence of acquired factor V inhibitor. The patient showed a right temporal lobe hemorrhage on the 33rd day of hospitalization, and 10 units of platelet concentrate were transfused. On the 34th day, oral prednisolone at 20 mg/day was initiated. On the 37th day, PT and APTT times were reduced to 11 and 19 sec, respectively. The factor V inhibitor became negative on the 57th day. Although this disease is extremely rare, it can occasionally cause severe bleeding symptoms. As a result, it is critical to make an accurate diagnosis and assess the treatment options. When abnormal coagulation is observed in a hemodialysis patient, bleeding symptoms should be examined and investigated as promptly as possible, keeping this disease in mind.