Reiwa 7 (Wa) 130 Professional Negligence Resulting in Death Case

In March 2025, at a hospital in Wakayama Prefecture, Japan, Dr. Kenji Tanaka, a surgeon, performed a laparoscopic cholecystectomy on patient Yuki Sato. During the operation, Dr. Tanaka mistakenly severed the common bile duct and failed to promptly recognize and repair the injury, leading to severe postoperative complications. The patient developed biliary peritonitis and died three days later. The prosecution alleged that Dr. Tanaka deviated from standard surgical practice, breaching his duty of care. The case, docketed as Reiwa 7 (Wa) 130, drew attention to surgical safety and physician accountability under Article 211 of the Penal Code for professional negligence resulting in death.

The Wakayama District Court found Dr. Tanaka guilty of professional negligence resulting in death. He was sentenced to 18 months in prison, suspended for three years. The court held that his failure to identify and correct the error during surgery fell below the acceptable medical standard.

The central dispute was whether the surgeon’s intraoperative error constituted a gross deviation from the standard of care, or an unfortunate but non-criminal complication. The defense argued that anatomical variations made the procedure unusually difficult, while the prosecution presented expert testimony that the injury was avoidable and the delay in recognition directly caused the fatal outcome.

The case intensified public and professional discourse on medical errors in Japan, prompting calls for mandatory surgical checklists, enhanced intraoperative imaging, and systemic reforms to encourage error reporting. It also raised awareness of patients’ rights and the criminal liability of physicians, balancing the need for accountability against fears of defensive medicine.