The value of cesarean scar diverticulum in diagnosis of adverse events during dilatation and curettage in patient with cesarean scar pregnancy.

Objective: The aim of the present study was to explore the relationship between the size of cesarean scar diverticulum (CSD) measured on preoperative magnetic resonance imaging (MRI) and adverse events during dilatation and curettage (D&C) procedure in patients with cesarean scar pregnancy (CSP).

Methods: The MRI of 197 CSP patients from October 2019 to August 2023 were retrospectively reviewed. The volume, area, and depth of CSD, residual myometrium thickness (RMT), and gestational sac diameter were recorded and tested for correlation with intraoperative estimated blood loss (EBL), and operation time and for any association with the intraoperative adverse events (intraoperative massive hemorrhage [39 cases] and D&C procedure failure [15 cases]). The Spearman test was used to characterize the correlation between the five MRI variables and both the EBL and operation time. The correlation between the five MRI variables and intraoperative adverse events was evaluated with student's t test and Mann-Whitney U test. Diagnostic power of the MRI variables was evaluated by the area under receiver operating characteristic curve (AUC).

Results: The volume, area, and depth of CSD and gestational sac diameter were positively correlated with both EBL and operation time, with the CSD volume having the highest correlation with them (r = 0.543 and 0.461, respectively). Conversely, the RMT displayed a negative correlation with the EBL and operation time. All five MRI variables were significantly associated with both intraoperative massive hemorrhage and D&C failure (all P < 0.001). The CSD volume demonstrated the highest AUC for diagnosing intraoperative massive hemorrhage and D&C failure at 0.893 (95% CI: 0.82-0.92) and 0.901 (95% CI: 0.85-0.94), respectively. The optimal cutoff values for CSD volume in predicting massive hemorrhage and D&C failure were determined to be 5.41 and 8.92 cm³, respectively, with corresponding sensitivities/specificities of 92.31/74.68 and 93.33/82.42, respectively.

Conclusion: Quantifying the size of CSD based on preoperative MRI could aid in evaluating risk during D&C in CSP patients, with CSD volume possessing higher diagnostic efficacy than the other four MRI indicators.