Diagnostic ultrasound to inform the surgical approach to cesarean delivery in patients at high risk for placenta accreta spectrum disorders.

Abstract

BACKGROUND Uterine sparing surgery has become an option for patients with placenta accreta spectrum disorders. The decision to perform a cesarean hysterectomy versus uterine sparing surgery is made intraoperatively. This study was undertaken to assess the value of ultrasound markers in predicting hysterectomy. OBJECTIVE To describe ultrasound markers associated with the need for cesarean hysterectomy in patients at risk of placenta accreta spectrum. STUDY DESIGN This was an analysis of a prospectively collected data of high risk placenta accreta spectrum patients between September 2023 and August 2024. Ultrasound examination was performed by an expert focusing on the diagnosis of placenta accreta spectrum. All patients were counselled regarding the management options available at our center, namely uterine-sparing surgery and hysterectomy. All patients opted for a uterine sparing surgery if safe and technically feasible. The final choice of surgical management approach was solely based on the intraoperative topography which describes the size and location of the abnormally adhered placenta. The primary outcome was the need for hysterectomy despite a preoperative plan for uterine-sparing surgery. RESULTS A total of 123 participants were enrolled: 93 placenta accreta spectrum cases and 30 non-placenta accreta scar dehiscence cases. Uterine sparing surgery was successful in 74 out of 93(79.6%) placenta accreta spectrum cases and 100% non-placenta accreta scar dehiscence cases. Least Absolute Shrinkage and Selection Operator penalised regression revealed intracervical hypervascularity >50%, distorted urinary bladder wall, and parametrial hypervascularity as the most influential predictors for hysterectomy. This best-fitted model achieved accuracy of 94% (95% CI: 81.3% - 99.3%) after model cross-validation. The combination of intracervical hypervascularity >50% and distorted bladder wall had the highest predictive probability for hysterectomy, with a value of 0.87 (95% CI: 0.81 - 0.93), sensitivity of 96.0% (95% CI 89.0 - 99.0%) and specificity of 92.0%(95% CI 62.0 - 100.0). CONCLUSION Comprehensive preoperative ultrasound can reasonably predict the appropriate surgical approach to placenta accreta spectrum. This can be achieved by assessing intracervical hypervascularity and a distorted urinary bladder wall using a combination of transabdominal, transvaginal, and color Doppler ultrasound techniques, as these signs have a strong correlation with the need for hysterectomy in a cohort where the intention to treat was uterine sparing surgery.