31 The Greener Scan: Replacing Routine MRCP With Ultrasound During Cholecystectomy to Meet NHS Net Zero Goals

Abstract Aim This study assesses the environmental impact of a change in practice at Torbay hospital, replacing routine MRCP with intraoperative ultrasound cholangiogram for the assessment of bile duct stones. Method: All laparoscopic cholecystectomies with indices suggestive of CBD stones were included. Data were collected from a prospectively maintained departmental database from Feb 2018 to Jan 2025. We collected data on the number of MRCP and IOUS procedures performed and how many MRCP we spared by performing IOUS cholangiogram. We also compared the average energy use and carbon emissions were estimated using published UK data. Results 1065 patients undergoing cholecystectomy at our institution had indices suggestive of choledocholithiasis. All of these patients were assessed using intraoperative ultrasound cholangiography (IOUS). CBD stones were detected in approximately 340 patients (32%) of the cases. By 2024, 97.5% of patients in this study did not require MRCP before or after surgery. Each MRCP requires approximately 20 kWh of electricity and produces 17.5 kg of CO₂ emissions, compared to just 0.2 kWh and 0.5 kg CO₂ for intraoperative ultrasound (IOUS). 1065 patients underwent IOUS, with only 57 requiring MRCP. Assuming IOUS replaced MRCP in the remaining 1008 cases, this equates to an estimated saving of 19,947 kWh of electricity and 17.1 tonnes of CO₂ emissions. Conclusions: Our data shows a major reduction in environmental impact when IOUS replaces MRCP in detecting CBD stones. This approach supports the NHS Net Zero strategy. We recommend that NHS guidelines consider IOUS as a first-line option in these cases.