P-BN20 An evaluation of the accuracy of sonography for the measurements of gallbladder polyps across 3 UK hospital trusts: should the surveillance guidelines be revised?

Background Transabdominal ultrasound scan (USS) is recommended for surveillance of gallbladder polyps (GBP), this is to stratify risk for premalignant potential. European Society of Gastrointestinal and Abdominal Radiology make recommendations based on increases of as small 2mm during sequential USS surveillance. Our aim is to determine the accuracy of USS in diagnosis and measurement of GBP. Methods Measurement data for all GBPs were gathered for three hospital trusts across a 12 year period and retrospectively reviewed. USS findings (diagnosis of GBP and GBP size) were compared with histological diagnosis and measurements, when both reports were available, in those patients who had underwent cholecystectomy at the time of data collection. Results For the first two hospital trusts, 778 USS were reviewed which identified patients with GBP. 78 patients had undergone cholecystectomy at time of data collection. Only 17/78 of patients had histological evidence of GBP. Of those without GBP, 37/61 had gallstones. For the third hospital trust, 41 GBP histological reports were identified, 20 could be directly compared with USS. Collectively 29 USS reports were directly compared with GBP histology reports. Only, 31% had results which were in agreement to within 1mm. The mean measurement discrepancy between both modalities was 5.41mm. Conclusions USS does not provide an accurate diagnosis of GBP, it is likely that USS misdiagnoses gallstones as GBP. Moreover, when comparing USS measurements with histological data, there is 31% accuracy of measurement to within 1mm in this cohort. Current guidelines recommend cholecystectomy if there is an interval change of 2mm or more; this data shows a measurement error of more than this.

P-O03 The Management of Gallbladder Polyps at a Single Trust: Are we compliant with European Guidelines?

Background Gallbladder polyps affect approximately 5% of the global population, with rates highest in those of Indian descent. 10% of polyps will have malignant potential based on their size or rapid growth rate, which are associated with a poor 5-year survival once advanced of less than 25%. As gallbladder polyps are common but gallbladder cancer is rare, it is a diagnostic challenge to determine which polyps are likely to be malignant. Adherence to guidelines regarding radiological follow up and definitive treatment, in the form of a cholecystectomy, is therefore vital. Methods Retrospective data collection and analysis was completed for all patients who had a biliary ultrasound between December 2013 and December 2016 to enable 5-year follow up, and a snapshot of 47 patients selected at random. Patients having a gallbladder “polyp” documented on their scan report were eligible for inclusion and adherence to European Society of Gastrointestinal and Abdominal Radiology (ESGAR) guidelines was assessed. Results Within the cohort there was a mean age of 56 years, with a male:female ratio of 17:30. All patients included were Caucasian, with 41 reporting “biliary symptoms” as the indication for the primary ultrasound. 26 patients were not followed up in adherence to guidelines, with 50% due to the sonographer reporting follow-up was not indicated on initial scan, 5 having unchanged polyp size and 2 discharged by the responsible consultant. Of the 21 who were followed up according to guidelines, 20 had a cholecystectomy within 5years, with none of these patients having cancer detected on histology. Conclusions Over 50% of patients within our cohort were not followed up according to the ESGAR guidelines. Although no patients in the study were found to have malignant polyps, the sample size is relatively small and limited to low-risk groups. We aim to expand this audit both locally and regionally, raise awareness of the importance of surveillance across the multi-disciplinary team, and produce local guidance for the outpatient setting.

Acute Abdomen and Multisystem Inflammatory Syndrome in Children with COVID-19: A Case Report and Review of Pathophysiology, Gastrointestinal Symptoms and Abdominal Radiology

Introduction: Pediatric patients with coronavirus disease 2019 (COVID-19) account for less than 5% of the total incidence. The scientific literature reports that most patients are asymptomatic or present mild symptoms. However, they may only manifest gastrointestinal symptoms and even present an acute abdomen; a severe form of presentation has been reported, called multisystem inflammatory syndrome in children. Case Presentation: We report a 10-year-old girl who presents COVID-19 in the form of an acute abdomen because of severe sigmoiditis who developed multisystem inflammatory syndrome together with shock. The patient fully recovered without sequelae with medical treatment. We provide computed tomography and ultrasound images and review scientific information available on gastrointestinal COVID-19 pathophysiology from the pediatric point of view. Conclusion: A high index of suspicion is needed for diagnosing COVID-19 in the event of any pediatric acute abdomen during the pandemic, and screening should be undertaken even without an epidemiologic setting and in the absence of respiratory symptoms or radiologic chest signs because acute abdomen could be a clinical presentation of MIS-C in children.