Acute appendicitis is the most common surgical emergency in children, and laparoscopic appendectomy is its standard treatment. Although intraoperative adverse events (iAEs) are recognized as an important determinant of surgical safety and outcome, no validated tool exists for grading them in children. ClassIntra, an internationally validated five-level severity classification of intraoperative adverse events, has been validated in adults. Its use in children is limited to two single-centre cohorts - one in pediatric neurosurgery and one in a mixed pediatric robotic surgery programme - in which it was applied prospectively by the operating teams. Its inter-rater reliability has never been assessed in a pediatric population, it has not been applied to video-recorded pediatric procedures, and no study has focused on pediatric appendectomy. Likewise, the association between intraoperatively graded event severity and postoperative complication severity graded with the pediatric-specific Clavien-Madadi classification has not been examined in children.
This prospective, single-center, single-surgeon, video-based pilot study (IDEAL Framework Stage 2a) evaluates whether ClassIntra can be feasibly applied to the laparoscopic phase of pediatric appendectomy. Eighty children aged 5 to under 18 years undergoing laparoscopic appendectomy for non-complicated acute appendicitis will be enrolled. Operative videos will be recorded, de-identified, assigned a case code, and independently assessed in randomized order by two pediatric surgeons from outside the operating institution, who remain blinded to all postoperative clinical data. Each observed event is characterized on three levels: event type (E1-E7), mechanism (GERT categories M1-M4), and severity (ClassIntra Grade I-V). Postoperative complications within 30 days are graded separately with the Clavien-Madadi classification by the principal investigator, independently of the video assessment.
The primary outcome is the feasibility of ClassIntra in this setting, evaluated as a progression-criteria profile rather than a composite rule, using three pre-specified criteria: inter-rater reliability (Gwet's AC1 \>= 0.60, the key indicator), applicable coverage (proportion of non-assessable cases \< 5%), and discriminative capacity (at least three of the five ClassIntra grades represented in the cohort). Secondary outcomes are descriptive: iAE incidence with Wilson score confidence intervals and the distribution of event types, mechanisms and severity grades. Exploratory hypotheses examine the association of intraoperative event severity with adherence to the institutional Enhanced Recovery After Surgery (ERAS) protocol, with time to medical readiness for discharge, and with Clavien-Madadi-graded postoperative complication severity.
The study involves no additional intervention, investigational product, or extra procedure for the participating children; care follows institutional standards throughout. Its purpose is to provide feasibility evidence and calibration parameters for subsequent multicenter validation studies, not to establish the validity of the classification system itself.
Age 5 to under 18 years.
Diagnosis of non-complicated acute appendicitis, based on clinical, laboratory and imaging findings.
Laparoscopic appendectomy planned.
General condition allowing standard surgical management and its associated complication risk (ASA Physical Status I or II).
Complicated appendicitis (perforation, periappendicular abscess, or peritonitis).
Emergency surgery for a non-appendicitis indication (e.g. ileus, intussusception).
Elective interval appendectomy (late procedure following complicated appendicitis).
Comorbidity corresponding to ASA Physical Status III or higher.
Consecutive children aged 5 to under 18 years who present to a single tertiary academic pediatric surgery department with non-complicated acute appendicitis and undergo laparoscopic appendectomy performed by the principal investigator, and whose parents or legal guardians provide written informed consent.
Cohort
Prospective
Laparoscopic appendectomy
Procedure/SurgeryLaparoscopic appendectomy performed as standard institutional care for non-complicated acute appendicitis. The study assigns no intervention: the procedure is routine care, and its operative video is recorded and independently graded for intraoperative adverse events during the laparoscopic phase.
Inter-Rater Reliability of ClassIntra Grading (Key Feasibility Indicator)
Agreement between two independent, blinded pediatric surgeon raters on the ClassIntra severity grade assigned to the laparoscopic phase of each operation, quantified with Gwet's AC1. The pre-specified feasibility threshold is AC1 \>= 0.60. Weighted Kappa and the intraclass correlation coefficient are reported as supporting measures. As a pre-specified sensitivity analysis, AC1 is additionally computed in the subset of videos with at least one identified intraoperative adverse event, since agreement on event-free cases is expected to be high and uninformative about grading discrimination. This is the key indicator of the feasibility profile; the three feasibility criteria are reported separately as progression criteria and are not combined into a composite rule.
Applicable Coverage of ClassIntra (Supporting Feasibility Indicator)
Proportion of enrolled cases that cannot be graded with ClassIntra by the raters, for any reason including insufficient video quality or incomplete assessment. The pre-specified feasibility threshold is a non-assessable proportion below 5%. Reported as a proportion with a 95% confidence interval, together with the reason for each non-assessable case.
Discriminative Capacity of ClassIntra (Supporting Feasibility Indicator)
Number of distinct ClassIntra severity grades (of the five possible grades, I to V) represented in the study cohort. The pre-specified feasibility threshold is representation of at least three of the five grades. The full grade distribution is additionally reported descriptively. No entropy or dispersion threshold is applied.
Incidence of Intraoperative Adverse Events
Proportion of operations in which at least one intraoperative adverse event is identified by the raters during the laparoscopic phase, reported as a point estimate with a Wilson score 95% confidence interval.
Distribution of Intraoperative Adverse Events by Event Type, Mechanism and Severity
Descriptive frequency map of all identified intraoperative adverse events across three levels: event type (E1 bleeding, E2 thermal injury, E3 avulsion, E4 serosal tear, E5 injury to adjacent organ, E6 detached clip, E7 spillage), mechanism (M1 excessive force or distance, M2 insufficient force or distance, M3 wrong orientation, M4 insufficient visualization), and ClassIntra severity grade (I to V). Events that cannot be assigned a mechanism are reported in a separate category.
Association Between Intraoperative Event Severity and Institutional ERAS Protocol Adherence (Exploratory)
Association between the presence of at least one ClassIntra Grade II or higher intraoperative adverse event and adherence to the institution's routine 20-item Enhanced Recovery After Surgery protocol, analyzed with logistic regression and reported as an odds ratio with a 95% confidence interval. Adherence data are obtained from routine clinical records, as the protocol is applied to all patients as standard care. This analysis is exploratory and hypothesis-generating; no adjustment for multiple testing is applied.
Association Between Intraoperative Event Severity and Time to Medical Readiness for Discharge (Exploratory)
Correlation between ClassIntra severity grade and the time from arrival in the post-anesthesia care unit until documented medical readiness for discharge, analyzed with Spearman rank correlation and reported as a correlation coefficient with a 95% confidence interval. Exploratory and hypothesis-generating.
Click on the lead sponsor to view all of their trials.
Ahmet Burak Doğan, MD
Lead sponsor
TC Erciyes University
Sponsor institution
