Placenta Accreta Spectrum Treatment With Intraoperative Multivessel Embolization: the PASTIME protocol

Multidisciplinary care of placenta accreta spectrum cases improves pregnancy outcomes, but the specific components of such a multidisciplinary collaboration varies between institutions. As experience with placenta accreta spectrum increases, it is crucial to assess new surgical techniques and protocols to help improve maternal outcomes and to advocate for hospital resources.

This study aimed to assess a novel multidisciplinary protocol for the treatment of placenta accreta spectrum that comprises cesarean delivery, multivessel uterine embolization, and hysterectomy in a single procedure within a hybrid operative suite.

This was a matched prepost study of placenta accreta spectrum cases managed before (2010-2017) and after implementation of the Placenta Accreta Spectrum Treatment With Intraoperative Multivessel Embolization protocol (2018-2021) at a tertiary medical center. Historical cases were managed with internal iliac artery balloon placement in selected cases with the decision to inflate the balloons intraoperatively at the discretion of the primary surgeon. Intraoperative Embolization cases were compared with historical cases in a 1:2 ratio matched on the basis of placenta accreta spectrum severity and surgical urgency. The primary outcome was a requirement for transfusion with packed red blood cells. Secondary outcomes included estimated surgical blood loss, operative and postoperative complications, procedural time, length of stay, and neonatal outcomes.

A total of 15 Placenta Accreta Spectrum Treatment With Intraoperative Multivessel Embolization cases and 30 matched historical cases were included in the analysis. There were no demographic differences noted between the groups. A median (interquartile range) of 0 units (0-2 units) of packed red blood cells were transfused in the Intraoperative Embolization group compared with 2 units (0-4.5 units) in the historical group (P=.045); 5 of 15 (33.3%) Intraoperative Embolization cases required blood transfusions compared with 19 of 30 (63.3%) cases in the historical group (P=.11). The estimated blood loss was significantly less in the Intraoperative Embolization group with a median (interquartile range) of 750 mL (450-1050 mL) compared with 1750 mL (1050-2500 mL) in the historical group (P=.003). There were no cases requiring massive transfusion (≥10 red blood cell units in 24 hours) in the Intraoperative Embolization group compared with 5 of 30 (16.7%) cases in the historical group (P=.15). There were no intraoperative deaths from hemorrhagic shock using the Intraoperative Embolization protocol, whereas this occurred in 2 of the historical cases. The mean duration of the interventional radiology procedure was longer in the Intraoperative Embolization group (67.8 vs 34.1 minutes; P=.002). Intensive care unit admission and postpartum length of stay were similar, and surgical and postoperative complications were not significantly different between the groups. The gestational age and neonatal birthweights were similar; however, the neonatal length of stay was longer in the Intraoperative Embolization group (median duration, 32 days vs 15 days; P=.02) with a trend toward low Apgar scores. Incidence of arterial umbilical cord blood pH <7.2 and respiratory distress syndrome and intubation rates were not statistically different between the groups.

A multidisciplinary pathway including a single-surgery protocol with multivessel uterine embolization is associated with a decrease in blood transfusion requirements and estimated blood loss with no increase in operative complications. The Placenta Accreta Spectrum Treatment With Intraoperative Multivessel Embolization protocol provides a definitive surgical method that warrants consideration by other centers specializing in placenta accreta spectrum treatment.