Implementation and outcomes of a uterine artery embolization and tranexamic acid protocol for placenta accreta spectrum

The role of MRI in "estimating" intraoperative bleeding during cesarean section for placenta accreta: A prospective cohort study

Objectives

The prenatal detection of placenta accreta spectrum (PAS) disorder is crucial for treatment strategy formulation. MRI descriptors may offer a more objective method for predicting PAS and clinical outcomes. The aim of this study is to investigate the predictive value of MRI examination for intraoperative blood loss in PAS cesarean section and elucidating the MRI descriptors that are more valuable for predicting intraoperative blood loss.

Methods

A prospective study was carried out on 164 pregnant women diagnosed with PAS. Maternal and neonatal perioperative characteristics were systematically collected. To evaluate the relationship between maternal and perioperative characteristics and intraoperative blood loss, as well as the predictive value of MRI descriptors on intraoperative blood loss, a multivariable linear regression analysis was performed.

Results

Patients were pre-grouped based on a combined ultrasound-MRI evaluation, with 108 cases (65.9 %) classified as placenta accreta, 47 cases (28.7 %) as placenta increta, and 9 cases (5.4 %) as placenta percreta. The results demonstrated that intraoperative blood loss was positively associated with partial MRI descriptors (F = 9.751, df = 15), such as placenta accreta (OR: 243.33, p = 0.006), cross-border blood vessels that pass through the uterine muscle layer (OR: 297.76, p = 0.012), interruption of hyperechoic uterus-bladder interface (bladder line) (OR: 342.59, p = 0.011), and subplacental hypervascularity (OR: 365.96, p = 0.027).

Conclusions

Preoperative MRI demonstrates promising predictive capabilities in estimating intraoperative blood loss for PAS patients. Pregnant women identified as having a high risk of intraoperative bleeding based on MRI findings should undergo closer antenatal monitoring in late pregnancy, along with more comprehensive preoperative blood preparation, to better ensure maternal and fetal safety.

Looking back to look forward: Has the time arrived for active management of obstetricians in placenta accreta spectrum?

Placenta accreta spectrum (PAS) is a relatively new obstetric condition which, until recently, was poorly understood. The true incidence is unknown because of the poor quality and heterogeneous diagnostic criteria. Classification systems have attempted to provide clarity on how to grade and diagnose PAS, but these are no longer reflective of our current understanding of PAS. This is particularly true for placenta percreta, which referred to extrauterine disease, as recent studies have demonstrated that placental villi associated with PAS have minimal potential to invade beyond the uterine serosa. It is accepted that PAS is a direct consequence of previous iatrogenic uterine injury, most commonly a previous cesarean section. Here, we "look back to look forwards"-starting with the primary predisposing factor for PAS, an iatrogenic uterine injury and subsequent wound healing. We then consider the evolution of definitions and diagnostic criteria of PAS from its first description over a century ago to current classifications. Finally, we discuss why modifications to the current classifications are needed to allow accurate diagnosis of this rare but life-threatening complication, while avoiding overdiagnosis and potential patient harm.

Cesarean hysterectomy for placenta accreta spectrum: Surgeon specialty-specific assessment

OBJECTIVE

To assess (i) clinical and pregnancy characteristics, (ii) patterns of surgical procedures, and (iii) surgical morbidity associated with cesarean hysterectomy for placenta accreta spectrum based on the specialty of the attending surgeon.

METHODS

The Premier Healthcare Database was queried retrospectively to study patients with placenta accreta spectrum who underwent cesarean delivery and concurrent hysterectomy from 2016 to 2020. Surgical morbidity was assessed with propensity score inverse probability of treatment weighting based on surgeon specialty for hysterectomy: general obstetrician-gynecologists, maternal-fetal medicine specialists, and gynecologic oncologists.

RESULTS

A total of 2240 cesarean hysterectomies were studies. The most common surgeon type was general obstetrician-gynecologist (n = 1534, 68.5%), followed by gynecologic oncologist (n = 532, 23.8%) and maternal-fetal medicine specialist (n = 174, 7.8%). Patients in the gynecologic oncologist group had the highest rate of placenta increta or percreta, followed by the maternal-fetal medicine specialist and general obstetrician-gynecologist groups (43.4%, 39.6%, and 30.6%, P < .001). In a propensity score-weighted model, measured surgical morbidity was similar across the three subspecialty groups, including hemorrhage / blood transfusion (59.4-63.7%), bladder injury (18.3-24.0%), ureteral injury (2.2-4.3%), shock (8.6-10.5%), and coagulopathy (3.3-7.4%) (all, P > .05). Among the cesarean hysterectomy performed by gynecologic oncologist, hemorrhage / transfusion rates remained substantial despite additional surgical procedures: tranexamic acid / ureteral stent (60.4%), tranexamic acid / endo-arterial procedure (76.2%), ureteral stent / endo-arterial procedure (51.6%), and all three procedures (55.4%). Tranexamic acid administration with ureteral stent placement was associated with decreased bladder injury (12.8% vs 23.8-32.2%, P < .001).

CONCLUSION

These data suggest that patient characteristics and surgical procedures related to cesarean hysterectomy for placenta accreta spectrum differ based on surgeon specialty. Gynecologic oncologists appear to manage more severe forms of placenta accreta spectrum. Regardless of surgeon's specialty, surgical morbidity of cesarean hysterectomy for placenta accreta spectrum is significant.

Risk factors for intensive care unit admission after cesarean hysterectomy for placenta accreta spectrum

OBJECTIVE

Placenta accreta spectrum (PAS) is a complex disorder of uterine wall disruption with significant morbidity and mortality, particularly at time of delivery. Both physician and physical hospital resource allocation/utilization remains a challenge in PAS cases including intensive care unit (ICU) beds. The primary objective of the present study was to identify preoperative risk factors for ICU admission and create an ICU admission prediction model for patient counseling and resource utilization decision making in an evidence-based manner.

METHODS

This was a case-control study of 145 patients at our PAS referral center undergoing cesarean hysterectomy for PAS. Final confirmation by histopathology was required for inclusion. Patient disposition after surgery (ICU vs post-anesthesia care unit) was our primary outcome and pre-/intra-/postoperative variables were obtained via electronic medical records with an emphasis on the predictive capabilities of the preoperative variables. Uni- and multivariate analysis was performed to identify independent predictive factors for ICU admission.

RESULTS

In this large cohort of 145 patients who underwent cesarean hysterectomy for PAS, with histopathologic confirmation, 63 (43%) were admitted to the ICU following delivery. These patients were more likely to be delivered at an earlier gestational age (34 vs 35 weeks, P < 0.001), have had >2 episodes of vaginal bleeding and emergent delivery compared to patients admitted to patients with routine recovery care (44% vs 18.3%, P = 0.009). Uni- and multivariate logistic regression showed an area under the curve of 0.73 (95% CI: [0.63, 0.81], P < 0.001) for prediction of ICU admission with these three variables. Patients with all three predictors had 100% ICU admission rate.

CONCLUSION

Resource prediction, utilization and allocation remains a challenge in PAS management. By identifying patients with preoperative risk factors for ICU admission, not only can patients be counseled but this resource can be requested preoperatively for staffing and utilization purposes.

Association between Antenatal Vaginal Bleeding and Adverse Perinatal Outcomes in Placenta Accreta Spectrum

Background and Objectives: Placenta accreta spectrum (PAS) disorders are placental conditions associated with significant maternal morbidity and mortality. While antenatal vaginal bleeding in the setting of PAS is common, the implications of this on overall outcomes remain unknown. Our primary objective was to identify the implications of antenatal vaginal bleeding in the setting of suspected PAS on both maternal and fetal outcomes. Materials and Methods: We performed a case-control study of patients referred to our PAS center of excellence delivered by cesarean hysterectomy from 2012 to 2022. Subsequently, antenatal vaginal bleeding episodes were quantified, and components of maternal morbidity were assessed. A maternal composite of surgical morbidity was utilized, comprised of blood loss ≥ 2 L, transfusion ≥ 4 units of blood, intensive care unit (ICU) admission, and post-operative length of stay ≥ 4 days. Results: During the time period, 135 cases of confirmed PAS were managed by cesarean hysterectomy. A total of 61/135 (45.2%) had at least one episode of bleeding antenatally, and 36 (59%) of these had two or more bleeding episodes. Increasing episodes of antenatal vaginal bleeding were associated with emergent delivery (p < 0.01), delivery at an earlier gestational age (35 vs. 34 vs. 33 weeks, p < 0.01), and increased composite maternal morbidity (76, 84, and 94%, p = 0.03). Conclusions: Antenatal vaginal bleeding in the setting of PAS is associated with increased emergent deliveries, earlier gestational ages, and maternal composite morbidity. This important antenatal event may aid in not only counseling patients but also in the coordination of multidisciplinary teams caring for these complex patients.

Management and Outcome of Women with Placenta Accreta Spectrum and Treatment with Uterine Artery Embolization

BACKGROUND

Placenta accreta spectrum (PAS) disorders are a continuum of placental pathologies with increased risk for hemorrhage, blood transfusion and maternal morbidity. Uterine artery embolization (UAE) is a safe approach to the standardization of complex PAS cases. The aim of this study is to analyze anemia and transfusion rate, outcome and anesthesiological management of women who underwent caesarean delivery with subsequent UAE for the management of PAS.

MATERIAL AND METHODS

This retrospective observational study included all pregnant women admitted to the University Hospital Frankfurt between January 2012 and September 2023, with a diagnosis of PAS who underwent a two-step surgical approach for delivery and placenta removal. Primary procedure included cesarean delivery with subsequent UAE, secondary procedure included placenta removal after a minim of five weeks via curettage or HE. Maternal characteristics, anesthesiological management, complications, anemia rate, blood loss and administration of blood products were analyzed.

RESULTS

In total, 17 women with PAS were included in this study. Of these, 5.9% had placenta increta and 94.1% had placenta percreta. Median blood loss was 300 (200-600) mL during primary procedure and 3600 (450-5500) mL during secondary procedure. In total, 11.8% and 62.5% of women received red blood cell transfusion during the primary and secondary procedures, respectively. After primary procedure, postpartum anemia rate was 76.5%. The HE rate was 64.7%. Regional anesthesia was used in 88.2% during primary procedure.

CONCLUSION

The embolization of the uterine artery for women diagnosed with PAS is safe. Anemia management and the implementation of blood conservation strategies are crucial in women undergoing UAE for the management of PAS.

Placenta previa percreta with surrounding organ involvement: a proposal for management

Placenta accreta spectrum encompasses cases where the placenta is morbidly adherent to the myometrium. Placenta percreta, the most severe form of placenta accreta spectrum (grade 3E), occurs when the placenta invades through the myometrium and possibly into surrounding structures next to the uterine corpus. Maternal morbidity of placenta percreta is high, including severe maternal morbidity in 82.1% and mortality in 1.4% in the recent nationwide U.S. statistics. Although cesarean hysterectomy is commonly performed for patients with placenta accreta spectrum, conservative management is becoming more popular because of reduced morbidity in select cases. Treatment of grade 3E disease involving the urinary bladder, uterine cervix, or parametria is surgically complicated due to the location of the invasive placenta deep in the maternal pelvis. Cesarean hysterectomy in this setting has the potential for catastrophic hemorrhage and significant damage to surrounding organs. We propose a step-by-step schema to evaluate cases of grade 3E disease and determine whether immediate hysterectomy or conservative management, including planned delayed hysterectomy, is the most appropriate treatment option. The approach includes evaluation in the antenatal period with ultrasound and magnetic resonance imaging to determine suspicion for placenta previa percreta with surrounding organ involvement, planned cesarean delivery with a multidisciplinary team including experienced pelvic surgeons such as a gynecologic oncologist, intra-operative assessment including gross surgical field exposure and examination, cystoscopy, and consideration of careful intra-operative transvaginal ultrasound to determine the extent of placental invasion into surrounding organs. This evaluation helps decide the safety of primary cesarean hysterectomy. If safely resectable, additional considerations include intra-operative use of uterine artery embolization combined with tranexamic acid injection in cases at high risk for pelvic hemorrhage and ureteral stent placement. Availability of resuscitative endovascular balloon occlusion of the aorta is ideal. If safe resection is concerned, conservative management including planned delayed hysterectomy at around 4 weeks from cesarean delivery in stable patients is recommended.