Development of a novel Classification of intra-operative Adverse Surgical Events (CiASE) in gynecological cancer...

Intra-operative adverse events contribute to postoperative morbidity and mortality. Although these events vary in their impact on patient recovery, no classification system has been available that accounts for this variation. We propose a scoring system that groups intra-operative adverse events in gynecological cancer surgery based on their impact on patient outcomes.

We conducted an investigator-led, multistage development of the Classification of intra-operative Adverse Surgical Events (CiASE) grading system. CiASE grades range from 0 (absence of intra-operative adverse events) to 4 (death) and were assigned by the investigators to 17 surgical case vignettes. Validation of the CiASE grading system was performed by 25 surgeons from 3 countries (Australia, New Zealand, and Ireland) who were blinded to the benchmark grade for each vignette. After validation, real-world analysis of CiASE was performed via applying grades to real cases reported to our institution for review between 2022 and 2023.

The benchmark CiASE grade assigned to the vignettes matched the surgeons' grading in 16.2 out of 17 cases on average, yielding an accuracy of 95.2%. Sensitivity for each individual grade ranged from 88% to 100%, and specificity ranged from 97.8% to 100%. Inter-rater agreement among the 25 surgeons was almost perfect, with a chance-adjusted weighted Krippendorff's Alpha score of 0.95 (95% CI 0.88 to 0.99). Among 179 real cases of intra-operative adverse events assessed, we classified 86 cases as CiASE grade 0 (48%; absence of intra-operative adverse events), 52 cases as grade 1 (29%; minimal impact on patient well-being), 24 cases as grade 2 (13%; moderate impact), 17 cases as grade 3 (10%; severe impact), and no cases as grade 4 (0%; death).

CiASE is a grading system for intra-operative adverse events that accounts for their impact on patient outcomes in gynecological cancer surgery. Future research is required to assess its utility for quality assurance, education, teaching, and feedback.