Hysterectomy for placenta accreta spectrum disorder: Impact of institutional surgical volume on patient outcomes

OBJECTIVE: To evaluate trends in hysterectomy case volume for placenta accreta spectrum (PAS) disorder over time and compare maternal outcomes between high- and low-volume centers. Specifically, we examined whether surgical volume influences severe maternal morbidity (SMM) and other key perioperative outcomes. METHODS: We conducted a population-based retrospective cohort study of patients aged 18-50 years who underwent hysterectomy for PAS in Ontario, Canada, from January 1, 2003, to January 1, 2022. Cases were identified using provincial administrative health databases. High-volume centers were defined as institutions performing ≥9 PAS hysterectomies annually, based on probability modeling and receiver operating characteristic analysis. The primary outcome was a validated composite measure of SMM, including massive transfusion, intensive care unit (ICU) admission, surgical complications, readmission, and length of hospital stay. RESULTS: Among 778 patients, 151 were treated at high-volume centers. These patients experienced significantly lower rates of SMM compared to those treated at low-volume centers (45.0% vs. 71.7%; adjusted relative risk [aRR] 0.59, 95% confidence interval [CI]: 0.49-0.72). Risks of massive transfusion (aRR 0.57, 95% CI: 0.47-0.70) and ICU admission (aRR 0.30, 95% CI: 0.15-0.58) were also markedly reduced. Length of hospital stay was shorter at high-volume centers (1.88 vs. 3.90 days; P < 0.0001). Each additional PAS hysterectomy performed in the prior year at a given institution was associated with a 3% reduction in SMM risk (aRR 0.97, 95% CI: 0.96-0.98). CONCLUSION: High-volume centers demonstrate significantly better maternal outcomes for PAS hysterectomy. These findings support centralizing PAS care to improve patient safety and surgical outcomes.