The reform of the way physicians work was started from April 2024. Restrictions on doctors' working hours is expected to be difficult to achieve the level required by the government. U40 Kyushu-Okinawa Branch conducted a questionnaire survey of young cardiovascular surgeons nationwide on their working conditions. While some institutions have taken measures such as streamlining doctors' work and shifting tasks, others seem to have made a few change to their previous work content. The reform of work styles of cardiovascular surgeons requires not only individual improvement of work styles, but also efforts by cardiovascular surgeons as a one team, including department heads and facility directors, and requires the involvement of academic societies and governments.

Background/Aims: Recent studies suggested a favorable effect of indigo naturalis (IN) in inducing remission for refractory ulcerative colitis (UC), however, the maintenance effect of IN for patients with UC remains unknown. Therefore, we conducted a prospective uncontrolled open-label study to analyze the efficacy and safety of IN for patients with UC. Methods: Patients with moderate to severe active UC (clinical activity index [CAI] ≥ 8) took 2 g/day of IN for 52 weeks. CAI at weeks 0, 4, 8, and 52 and Mayo endoscopic subscore (MES) and Geboes score (GS) at weeks 0, 4, and 52 were assessed. Clinical remission (CAI ≤ 4), mucosal healing (MES ≤ 1), and histological healing (GS ≤ 1) rates at each assessment were evaluated. Overall adverse events (AEs) during study period were also evaluated. The impact of IN on mucosal microbial composition was assessed using 16S ribosomal RNA gene sequences. Results: Thirty-three patients were enrolled. The rates of clinical remission at weeks 4, 8, and 52 were 67%, 76%, and 73%, respectively. The rates of mucosal healing at weeks 4 and 52 were 48% and 70%, respectively. AEs occurred in 17 patients (51.5%) during follow-up. Four patients (12.1%) showed severe AEs, among whom 3 manifested acute colitis. No significant alteration in the mucosal microbial composition was observed with IN treatment. Conclusions One-year treatment of moderate to severe UC with IN was effective. IN might be a promising therapeutic option for maintaining remission in UC, although the relatively high rate of AEs should be considered.