Niels Keekstra
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Niels Keekstra has a total of 7 co-authors. Here are the top co-authors by number of shared publications:
- Fabian A. Holman
Department of Surgery, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
1 shared publication - Hein Putter
Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, the Netherlands
1 shared publication - Jaap F. Hamming
Department of Vascular Surgery, Leiden University Medical Center, Leiden, The Netherlands
1 shared publication - Jan van Schaik
Department of Vascular Surgery, Leiden University Medical Center, Leiden, The Netherlands
1 shared publication - Joost Renier van der Vorst
Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
1 shared publication - Tessa M. Hers
Department of Surgery, Leiden University Medical Centre (LUMC), 2333 ZA Leiden, The Netherlands
1 shared publication
Latest Publications
- Open Access
- 30 June 2022
- Published by Wolters Kluwer Health in International Journal of Surgery Case Reports
- Vol. 96 (C) , 107378
Intestine perforation by an accidental ingested SARS-CoV-2 nasopharyngeal swab; a case report
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:
- 30 June 2022
- Published by Wolters Kluwer Health in International Journal of Surgery Case Reports
- Vol. 96 (C) , 107378
Open AccessIntestine perforation by an accidental ingested SARS-CoV-2 nasopharyngeal swab; a case report
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:
- Open Access
- 20 November 2021
- Published by MDPI AG in Journal of Clinical Medicine
- Vol. 10 (22) , 5426
Inaccurate Risk Assessment by the ACS NSQIP Risk Calculator in Aortic Surgery
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.
- 20 November 2021
- Published by MDPI AG in Journal of Clinical Medicine
- Vol. 10 (22) , 5426
Open AccessInaccurate Risk Assessment by the ACS NSQIP Risk Calculator in Aortic Surgery
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.