OBJECTIVE: Our goal was to develop a system using virtual reality (VR) technology to test the haptic skills of medical students. Currently, surgical skills are learned on live patients in a clinical environment in which the student practices under the close supervision of an experienced surgeon. We are interested in using haptic feedback devices to enhance surgical skills, because simulated touch in a virtual world improves the performance of trainee surgeons. In this study, we evaluated the efficacy of a test that evaluates the surgical skill of medical students by using a VR simulator.
METHODS: We used a microsurgical simulator with a force-feedback system. Its effectiveness in helping 36 medical students to acquire the tactile skills used in microscopic surgery was evaluated experimentally. Operating time and the number of sites of hemorrhage were measured to evaluate surgical aptitude. We also evaluated system performance with respect to reality, immersiveness, and operability as secondary measures. Data were analyzed using descriptive methods.
RESULTS: The operating time and number of hemorrhagic sites were positively correlated. Subject students were clustered into three groups: dexterous, awkward, or clumsy. The relation between the number of hemorrhages in the retina and immersion and operability differed between the group of would-be surgeons and those of would-be internists and pediatricians. All the students commented that the simulator was a useful tool for medical education.
CONCLUSIONS: The VR simulator can be used not only to teach and evaluate subtle tactile and surgical skills relevant to the surgical profession, but also to test the aptitude of medical students. The training transfer from a haptic simulator to actual practice methodology should be quantifiable in the near future. This work has steered medical informatics research into a new type of medical education.

Objective : The aim of this study is to describe a series of patients undergoing reoperation due to hemolytic anemia after mitral valve surgery and assess the mechanisms and surgical outcomes. Methods : Between 2009 and 2014, we performed redo mitral valve surgery in 11 patients who had refractory hemolytic anemia after mitral valve surgery at Kyoto University Hospital. The mean age of the patients was 72.2±6.8 years old, and there were 5 men. Results : Preoperative echocardiography demonstrated that only 3 patients had ≥ grade 3 mitral regurgitation (MR), the rest of the patients had only mild to moderate MR. The mechanisms of severe hemolysis included paravalvular leakage (PVL) after mitral valve replacement (MVR) in 8 patients, structural valve deterioration (SVD) after MVR using a bioprosthesis in one, and residual/recurrent mitral regurgitation after mitral valve plasty (MVP) in two. All the patients except one (re-MVP) underwent MVR. The mean interval between previous operation and current operation was 14.1±9.4 years in post-MVR cases, and 2.0±1.9 years in post-MVP cases. There were three late deaths, one of which was due to cardiac death (exacerbation of heart failure due to pneumonia). There was one patient who required re-MVR for recurrent hemolysis due to PVL after MVR. Conclusion : Although hemolytic anemia after mitral valve surgery is rare, it often requires reoperation regardless of the degree of MR at late follow-up period. Thus, patients after mitral valve surgery should be carefully followed-up.

In recent years, the number of patients with non-tuberculosis mycobacteria (NTM) has rapidly increasing.According to the nationwide survey conducted in 2014, the number of patients with NTM was reported to increase 9.7 times compared to the survey in 1980. Among them, the patients with Mycobacterium avium complex (MAC) account for about 88.8% of them. It is the main cause of the rapid increase of NTM patients mainly in middle-aged and elderly woman. To treat patients with MAC, it is common to do chemotherapy over one year after the bacteria becomes negative. Among experts of NTM, it is recommended to do chemotherapy preventing generation of resistant bacteria by using clarithromycin (CAM) and rifampicin and ethambutol (EB) in combination. Meanwhile, a monotherapy of CAM and high-dose EB administration over a long period are not currently recommended due to side effects. However, it has not been clarified so far how many such drug prescriptions had existed. Therefore, in this study, we investigated the actual drug prescription of 571 patients who were presumed to be NTM in health insurance data collected from 2015 to 2016. As a result, about 5.1% (29 cases) of CAM monotherapy and 4.4% (15 cases) of EB high-dose prescription over 3 months were observed. In general, because NTM is a case where a long-term antibiotic treatment is required, it increases the possibility of any disadvantages exerting on patients. Hence, we consider it is an important and urgent matter to inform the correct information widely to clinical workers and sites.