ABSTRACT
BACKGROUND: In Canada, endoscopy is primarily performed by gastroenterologists and surgeons, and some studies report that colonoscopies performed by nongastroenterologists have more complications and higher rates of future colorectal cancer. Our objective was to determine whether rural-based nongastroenterologist endoscopists are achieving quality benchmarks in colonoscopy. METHODS: This quality improvement initiative prospectively evaluated 6 key performance indicators (KPIs) (cecal intubations, polyp detection [males and females; for first-time colonoscopies on patients aged ≥ 50 yr], bowel preparations, patient comfort and withdrawal times) on consecutive colonoscopies performed by participating Alberta North Zone endoscopists. The study period was June 2018 to March 2020. Overall and individual endoscopist's KPIs were compared with standard benchmarks. Additional performance indicators included mean number of polyps per colonoscopy and an exploration of study-defined sedation-related level of consciousness. RESULTS: Data were collected on 6212 colonoscopies performed by 16 endoscopists (9 surgeons, 5 family physicians and 2 internists) in 6 hospitals. All 6 KPI benchmarks were achieved when results were pooled over all endoscopists in the study. Overall, cecal intubation occurred in 6006 of 6209 (96.7%, 95% confidence interval 94.5%-99.0%) cases. Polyp detection was 65.9% (592/898) and 49.8% (348/699) for male and female patients, respectively, aged 50 years or older. Variability in individual endoscopist results existed, especially for the mean number of polyps per 100 colonoscopies and sedation-related level of consciousness. INTERPRETATION: Overall, Alberta North Zone endoscopists are performing high-quality colonoscopies, collectively achieving all 6 KPIs. To understand endoscopic performance and encourage individual and group reflection on endoscopic practices, Canadian endoscopists are encouraged to participate in similar colonoscopy quality initiative studies.
ABSTRACT
We previously demonstrated that short-term administration of a combination of anti-LFA-1 and anti-CD154 monoclonal antibodies (mAbs) induces tolerance to neonatal porcine islet (NPI) xenografts that is mediated by regulatory T cells (Tregs) in B6 mice. In this study, we examined whether the coinhibitory molecule PD-1 is required for the induction and maintenance of tolerance to NPI xenografts. We also determined whether tolerance to NPI xenografts could be extended to allogeneic mouse or xenogeneic rat islet grafts since we previously demonstrated that tolerance to NPI xenografts could be extended to second-party NPI xenografts. Finally, we determined whether tolerance to NPI xenografts could be extended to allogeneic mouse or second-party porcine skin grafts. Diabetic B6 mice were transplanted with 2,000 NPIs under the kidney capsule and treated with short-term administration of a combination of anti-LFA-1 and anti-CD154 mAbs. Some of these mice were also treated simultaneously with anti-PD-1 mAb at >150 days posttransplantation. Spleen cells from some of the tolerant B6 mice were used for proliferation assays or were injected into B6 rag(-/-) mice with established islet grafts from allogeneic or xenogeneic donors. All B6 mice treated with anti-LFA-1 and anti-CD154 mAbs achieved and maintained normoglycemia until the end of the study; however, some mice that were treated with anti-PD-1 mAb became diabetic. All B6 rag(-/-) mouse recipients of first- and second-party NPIs maintained normoglycemia after reconstitution with spleen cells from tolerant B6 mice, while all B6 rag(-/-) mouse recipients of allogeneic mouse or xenogeneic rat islets rejected their grafts after cell reconstitution. Tolerant B6 mice rejected their allogeneic mouse or xenogeneic second-party porcine skin grafts while remaining normoglycemic until the end of the study. These results show that porcine islet-specific tolerance is dependent on PD-1, which could not be extended to skin grafts.
