The importance of off the job training in surgical education are widely recognized. The Japanese Board of Cardiovascular Surgery has required a board candidate to do at least 30 hours of off the job training from 2017. U-40 Basic Lecture Course are held annually for young cardiovascular surgeon to learn about basic surgical skills. U-40 Advanced Lecture Course was started to provide opportunity to have more advanced hands-on lecture for young cardiovascular surgeon. However, after the COVID-19 pandemic, the opportunity to hold hands-on seminars are highly limited. In such circumstances, we held a hybrid hands-on seminar. We report details about the hybrid hands-on seminar.

A 65-year-old man who had been taking warfarin for a mitral mechanical valve, was transported to our hospital for acute heart failure 3 months after switching to edoxaban. The fluoroscopy revealed restriction of the mechanical valve opening, and the catheterization showed an increased pressure gradient of the mechanical valve. The patient was diagnosed with valve thrombosis, and emergency redo mitral valve replacement was performed. The patient recovered well without complication. In cases with mechanical heart valves, sufficient explanation and education about warfarin administration is mandatory for patients' home doctors as well as patients and their families.

Objective: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant B.1.1.529 (Omicron) was first detected in Japan in November 2021. In Osaka, public health centres subsequently increased active case finding and encouraged self-isolation. This study investigated the effectiveness of these countermeasures. Methods: Cases targeted for analysis were persons who had neither recently travelled abroad nor had contact with foreign tourists but tested positive for SARS-CoV-2 between 24 November 2021 and 4 January 2022 and were suspected or confirmed to have the Omicron variant. We performed a descriptive analysis and calculated the reproduction number (R) for each generation using the branching process method. Genomic sequencing data were analysed to plot a haplotype network. Results: A total of 251 cases were analysed. The median age was 30 years, and 46% (115/251) were in their 20s or younger. The first Omicron case in Osaka was detected on 21 December 2021. Local public health centres conducted health monitoring and contact tracing. We analysed R, using information from six clusters, including 42 pairs with a clear relationship between the case and the infected contact (infector–infectee pairs); the clusters had 19, 21 and 2 cases in each subsequent generation. The basic R (t = 0) was estimated to be 3.2, and subsequent generations (t = 1, 2) of R decreased to 1.1 and 0.1, respectively. The haplotype network showed that these cases constituted a monophyletic group with others detected around Osaka, indicating that these case-related clusters had been contained and were not involved in the nationwide Omicron waves. Discussion: Active case finding and self-isolation were found to be effective in limiting the spread of an emerging novel variant.