The surgical replacement of human vessels or valves using allografts (homografts) has been reported as a useful method. Nevertheless, little is known about preservation effects and immunological consequences using low temperature preservation and cryopreservation. In this study, we examined the histological changes and immunological changes of cryopreserved aorta in a rat model, and compared the results with those of low temperature preserved aorta. Ascending aorta was harvested from Wister-King rats and preserved in TC199 solution at 4°C (low temperature preservation group) and cryopreserved (cryopreservation group) for 1, 2, and 3 weeks. The preserved aorta was then transplanted to the abdominal aorta of the recipient rat. The graft patency and histology, including immunohistochemical stain (IgG, IgM, C3), were assessed at 3 weeks after transplantation. In the cryopreservation group prominent intimal thickness was observed. However, cell infiltration from adventitia was observed in the low temperature preservation group. Immunohistochemical stains indicated the deposit of immunoglobulin was seen after transplantation in both groups. The result of this study suggested that successful preservation of aorta was possible at one week with low temperature preservation and 3 weeks with cryopreservation in the rat model.

We report a case of endovascular aneurysm repair (EVAR) in a patient with an aortocaval fistula (ACF) who presented with congestive heart failure due to left-to-right shunting. The patient was an 80-year-old man who complained of sudden respiratory discomfort and lower leg edema, and was admitted to the emergency department. The initial diagnosis on admission was acute heart failure. Because the inferior vena cava was visualized by angiography in the arterial phase due to the fistula from the abdominal aorta, after admission, we rediagnosed this case as ACF. As medical treatment did not improve the patient's symptoms, emergency surgery was decided upon. Because preoperative evaluation was able to rule out the existence of an aortic aneurysm, ACF closure was performed by EVAR. The postoperative course was uneventful and the patient was discharged 15 days after surgery. ACF without aortic aneurysm is uncommon and is not easily diagnosed. This case demonstrated that EVAR can be an effective treatment option for ACF.

Seven children aged 3 to 14 years, underwent cardiac valve replacement with a St. Jude Medical valve prosthesis. In 4, the valve was placed in the aortic position, in 2 in the mitral position and in 1 in the aortic and mitral position. Three patients underwent Konno's procedure. We followed up them from 2.3 to 9.3 years (mean follow-up 6.0 years). There were no operative or hospital deaths. One patient died after delivery by caesarean section 9.3 years after the operation. All patients recieved warfarin and antiplatelet agents for postoperative anticoagulation and no thromboembolic or bleeding complications occured. All survivors did not need reoperation and they were in New York Heart Association functional class 1 without somatic growth retardation.

Three patients with hyperosmolar hyperglycemic non-ketotic diabetic coma (HHNKDC) following open-heart surgery are presented. Because the symptoms of HHNKDC are not specific, it is difficult to recognize this unique complication in the early postoperative stage. The mortality rate of this complication is high. Thus, HHNKDC should be recognized as early as possible after open-heart surgery, since it is curable if diagnosed at an early stage.

Introduction: Work style reform of medical doctors is now an actively discussed matter in Japan. There is also the problem of how to balance the management of legal working hours and the value of medical education in junior residency programs. In particular night and holiday shifts in emergency departments are one of the most important causes of working hour elongation for junior residents. We tried to construct a legally appropriate management method to control their working hours including night and holiday shifts. Method: One-Month Variable Working Hours System and two-shift system were applied to labor management in the medical residency program. Night and holiday working hours were included in regular working hours. Day-time working hours were adjusted to the weekly schedule of each clinical department to cover most of its daily work. Result: Overtime working hours of all residents, including the night and holyday shifts, were managed within the legal limits of 45 hours a month, unless additional overtime work was required. Discussion: Managing worktime through the use of the One-Month Variable Working Hours System is thought to be feasible. In the junior residency program, night and holiday shifts in the emergency department could also be balanced.