Internal iliac artery balloon occlusion for placenta accreta spectrum disorder: outcomes and factors influencing efficacy

BACKGROUND: Placenta accreta spectrum disorder (PASD) is a major obstetric complication associated with life-threatening haemorrhage. Prophylactic internal iliac artery balloon occlusion (IIABO) is used in many centres to reduce intraoperative blood loss but success rates are variable. METHODS: We reviewed 20 consecutive patients with PASD over a twenty-one-month period stratified by procedure type [total abdominal hysterectomy (TAH) versus conservative myometrial repair (MR)] and balloon occlusion use. Estimated blood loss (EBL) was recorded. Welch's t-tests compared groups, and a two-way analysis of variance (ANOVA) assessed the effects of balloon use and procedure type. Effect sizes were expressed as Cohen's d and η². RESULTS: Mean EBL was significantly lower with balloon use than without (1600 ± 666 mL vs. 3222 ± 1871 mL, p = 0.034, Cohen's d = - 1.15). Two-way ANOVA confirmed a main effect of balloon use (η² = 0.28), while procedure type showed no independent effect (p = 0.504). However, EBL values were widely dispersed- with balloons: median 1500 mL (interquartile range {IQR} 1200-1850), range 800-3000; without balloons: median 3000 mL (IQR 1600-5000), range 900-6000 which highlighted the variable efficacy at an individual level. CONCLUSION: Prophylactic balloon occlusion reduces blood loss overall in both TAH and MR for PASD, but its efficacy is highly variable. Collateral circulation and scar defect morphology likely underpin this variability, and further research should focus on refining preoperative risk stratification to guide individualised surgical planning with the aid of available imaging techniques.