Objectives: The aim of this retrospective study was to assess the predictive performance of the American College of Surgeons (ACS) risk calculator for aortic aneurysm repair for the patient population of a Dutch tertiary referral hospital. Methods: This retrospective study included all patients who underwent elective endovascular or open aortic aneurysm repair at our institution between the years 2013 and 2019. Preoperative patient demographics and postoperative complication data were collected, and individual risk assessments were generated using five different current procedural terminology (CPT) codes. Receiver operating characteristic (ROC) curves, calibration plots, Brier scores, and Index of Prediction Accuracy (IPA) values were generated to evaluate the predictive performance of the ACS risk calculator in terms of discrimination and calibration. Results: Two hundred thirty-four patients who underwent elective endovascular or open aortic aneurysm repair were identified. Only five out of thirteen risk predictions were found to be sufficiently discriminative. Furthermore, the ACS risk calculator showed a structurally insufficient calibration. Most Brier scores were close to 0; however, comparison to a null model though IPA-scores showed the predictions generated by the ACS risk calculator to be inaccurate. Overall, the ACS risk calculator showed a consistent underestimation of the risk of complications. Conclusions: The ACS risk calculator proved to be inaccurate within the framework of endovascular and open aortic aneurysm repair in our medical center. To minimize the effects of patient selection and cultural differences, multicenter collaboration is necessary to assess the performance of the ACS risk calculator in aortic surgery.

Introduction and importance: Gastrointestinal tract perforations as a result of foreign body ingestion are rare. Most ingested foreign bodies pass the intestines without complications. However, in 1 % of cases intestinal perforation occurs. We present the case of a 56-year old patient with an extensive surgical medical history who presented at the emergency department with progressive abdominal pain two weeks after accidental SARS-CoV-2 swab ingestion. Case presentation: On presentation patient was tachycardic and had generalized abdominal tenderness. A CT scan showed free intraperitoneal air and fatty infiltration of the ileocecal anastomosis (after an ileocoecal resection at the age of 46) continuing to the distal sigmoid. Emergency exploratory laparotomy revealed a covid swab in the abdominal cavity with an indurated area of the sigmoid without perforation. Post-operative care was uneventful, and patient was dismissed after four days. Clinical discussion: Due to his medical history and the fact he was advised to regularly self-test for COVID, he routinely performed an oropharyngeal swab. Unfortunately, this resulted in swallowing the swab. A perforation tends to happen in regions of acute angulation, such as an anastomosis. Although the CT scan suggested the perforation was at the ileocecal anastomosis, no perforation was found during surgery, while the swab was found loose in the peritoneal cavity. Conclusion: Initial treatment should focus on endoscopic removal. In the case of gasto-intestinal perforation, surgery becomes the treatment of choice. A foreign body can migrate to peritoneal cavity without peritonitis or visible perforation perioperative. Highlights: