Evaluation of perioperative complications using a newly described staging system for placenta accreta spectrum

Quantifying placenta accreta spectrum severity and its associated blood loss: a novel transvaginal ultrasound scoring system

BACKGROUND

Hemorrhage associated with placenta accreta spectrum (PAS) is a leading cause of maternal morbidity and mortality. Estimating blood loss in these individuals is a critical component of comprehensive preoperative planning.

OBJECTIVE

A semiquantitative score based on transvaginal ultrasound was developed and tested to predict PAS, estimate its severity, and blood loss in individuals with clinical and ultrasound evidence suggesting PAS.

STUDY DESIGN

A secondary analysis was conducted of prospectively collected data from a quaternary center of patients with suspected accreta on 2D ultrasound and clinical suspicion. A predetermined scoring system was applied based on three components: (1) uterine wall (score 0: no loss of hypo-translucent uterine wall with overlying placenta in the lower uterine segment; 1: loss of hypo-translucent <3-cm defect; 2: 3-6-cm defect; and 3: >6-cm defect); (2) arterial vascularity at the uterine wall defect (score 0: no vessels observed; 1: 1-2 vessels over the defect; 2: 3-5 vessels; and 3: >5 vessels); and (3) cervical involvement (score 0: normal cervical length without previa; 1: previa with normal cervical length; 2: short cervix with previa, minimal vascularity and small lacunae; 3: short cervix with previa, increased vascularity and large lacunae). Each patient's three domain scores determined a cumulative, final score of 0-9. Patients were managed at the discretion of a multi-disciplinary team and patient's preference among the following options: cesarean delivery with placenta removal, cesarean delivery with placenta in-situ (conservative) with or without delayed hysterectomy, or cesarean hysterectomy. The frequency of different degrees of placental invasion per pathology examination per score unit was registered. Multiple linear regression analysis was performed for association of blood loss according to score adjusted by risk factors for PAS.

RESULTS

A total of 73 patients were evaluated. All 11 patients who had a score of 0 had cesarean delivery with placenta removal without evidence of intraoperative PAS, thus resulting in a 100% negative predictive value. The remaining 62 had scores between 1 and 9. Among patients with scores 0-3 (n=20), only one had intraoperative PAS, yielding a negative predictive value of 97%. Higher scores were associated with severe PAS forms (r=0.301, P=.02). Based on the associations between PAS scores, clinical correlation, and blood loss, we divided patients into four categories: Category 0: PAS score 0; Category 1: scores 1-3; Category 2: scores 4-6; and Category 3: scores 7-9. The median blood loss in Category 0=635±352 mL, Category 1=634±599 mL, Category 2=1549±1284 mL, and Category 3=1895±2106 mL (P<.001). On multivariable analysis, Category 2 (β=0.97, P<.01) and Category 3 (β=1.26, P<.003) were associated with significantly greater blood loss than Category 0, irrespective of type of surgery.

CONCLUSION

The transvaginal ultrasound score separates groups at low risk (Category 0) and at higher risk of PAS (Categories 1-3). Categories 1-3 may provide important clinical information to estimate the risk of severe forms of PAS and of blood loss during surgery. VIDEO ABSTRACT.

Prediction of Placenta Accreta Spectrum by Prenatal Ultrasound Staging System in Women with Placenta Previa with Scarred Uterus

Background

Placenta accreta spectrum (PAS) disorders are defined as range of pathological adherence/invasion of placenta. Prenatal diagnosis of PAS disorders using ultrasound doppler can optimize fetomaternal outcome and reduce complications.

Objectives

To study the predictive value of prenatal ultrasound staging system for the presence and severity of placenta accreta spectrum and its correlation with fetomaternal outcomes.

Method

This was a prospective cohort study conducted in Obstetrics and Gynecology department at VMMC and Safdarjung Hospital, New Delhi, over a period of 18 months. It included 50 women with singleton pregnancy > 28 weeks with placenta previa with scarred uterus after taking informed consent and ethics committee approval. All the women underwent ultrasound and PAS score was assigned, which was correlated with intraoperative FIGO grade, histopathology and fetomaternal outcomes.

Results

In 50 women enrolled, prenatal ultrasound staging was performed and PAS score 0, 1, 2 and 3 was assigned. Cesarean hysterectomy was required in all 21(42%) women with PAS score > 0 (PAS 1, 2, 3). Intraoperative, focal and complete invasion was seen in 4% and 38%, respectively, and FIGO grade 1, 2, 3, 4, 5 and 6 was observed in 46%, 16%, 30%, 0%, 6% and 2%, respectively. On histopathology, 14.28% (3/21) with PAS > 0 did not have any invasion, while 85.71% (18/21) had invasion, i.e., accreta, increta and percreta in 57.14%, 19.05% and 9.52%, respectively. Considering histopathology as gold standard, the overall sensitivity, specificity, PPV, NPV and diagnostic accuracy of PAS score were 100%, 90.62%, 85.71%, 100% and 94%, respectively.

Conclusion

Prenatal ultrasound staging system is a simple and feasible screening modality. Hence, it should be used in all high-risk women with placenta previa and scarred uterus for definitive prenatal diagnosis of PAS.

Urological complications in women undergoing Cesarean section for placenta accreta spectrum disorders: systematic review and meta-analysis

OBJECTIVE

To report on the occurrence of urological complications in women undergoing Cesarean section for placenta accreta spectrum disorders (PAS).

METHODS

MEDLINE, EMBASE and the Cochrane databases were searched electronically up to 1 November 2022. Studies reporting on the urological outcome of women undergoing Cesarean section for PAS were included. Two independent reviewers performed data extraction using a predefined protocol and assessed the risk of bias using the Newcastle-Ottawa scale for observational studies, with disagreements resolved by consensus.The primary outcome was the overall occurrence of urological complications. Secondary outcomes were the occurrence of any cystotomy, intentional cystotomy, unintentional cystotomy, ureteral damage, ureteral fistula and vesicovaginal fistula. All outcomes were explored in the overall population of women undergoing surgery for PAS. In addition, we performed subgroup analyses according to the type of surgery (Cesarean hysterectomy, or conservative surgery or management), severity of PAS at histopathology (placenta accreta/increta and placenta percreta), type of intervention (planned vs emergency) and number of cases per year. Random-effects meta-analyses of proportions were used to analyze the data.

RESULTS

There were 62 studies included in the systematic review and 56 were included in the meta-analysis. Urological complications occurred in 15.2% (95% CI, 12.9-17.7%) of cases. Cystotomy complicated 13.5% (95% CI, 9.7-17.9%) of surgical operations. Intentional cystotomy was required in 7.7% (95% CI, 6.5-9.1%) of cases, while unintentional cystotomy occurred in 7.2% (95% CI, 6.0-8.5%) of cases. Urological complications occurred in 19.4% (95% CI, 16.3-22.7%) of cases undergoing hysterectomy and 12.2% (95% CI, 7.5-17.8%) of those undergoing conservative treatment. In the subgroup analyses, urological complications occurred in 9.4% (95% CI, 5.4-14.4%) of women with placenta accreta/increta and 38.5% (95% CI, 21.6-57.0%) of those described as having placenta percreta, and included mainly cystotomy (5.5% (95% CI, 0.6-15.1%) and 22.0% (95% CI, 5.4-45.5%), respectively). Urological complications occurred in 15.4% (95% CI, 8.1-24.6%) of cases undergoing a planned procedure and 24.6% (95% CI, 13.0-38.5%) of those undergoing an emergency intervention. In subanalysis of studies reporting on ≥ 12 cases per year, the incidence of urological complication was similar to that reported in the primary analysis.

CONCLUSIONS

Women undergoing surgery for PAS are at high risk of urological complication, mainly cystotomy. The incidence of these complications was particularly high in women described as having placenta percreta at birth and in those undergoing emergency surgical intervention. The high heterogeneity between the included studies highlights the need for a standardized protocol for the diagnosis of PAS to identify prenatal imaging signs associated with the increased risk of urological morbidity at delivery. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Modified Delphi study of ultrasound signs associated with placenta accreta spectrum

OBJECTIVE

To determine, by expert consensus through a modified Delphi process, the role of standardized and new ultrasound signs in the prenatal evaluation of patients at high risk of placenta accreta spectrum (PAS).

METHODS

A systematic review of articles providing information on ultrasound imaging signs or markers associated with PAS was performed before the development of questionnaires for the first round of the Delphi process. Only peer-reviewed original research studies in the English language describing one or more new ultrasound sign(s) for the prenatal evaluation of PAS were included. A three-round consensus-building Delphi method was then conducted under the guidance of a steering group, which included nine experts who invited an international panel of experts in obstetric ultrasound imaging in the evaluation of patients at high risk for PAS. Consensus was defined as agreement of ≥ 70% between participants.

RESULTS

The systematic review identified 15 articles describing eight new ultrasound signs for the prenatal evaluation of PAS. A total of 35 external experts were approached, of whom 31 agreed and participated in the first round. Thirty external experts (97%) and seven experts from the steering group completed all three Delphi rounds. A consensus was reached that a prior history of at least one Cesarean delivery, myomectomy or PAS should be an indication for detailed PAS ultrasound assessment. The panelists also reached a consensus that seven of the 11 conventional signs of PAS should be included in the examination of high-risk patients and the routine mid-gestation scan report: (1) loss of the 'clear zone', (2) myometrial thinning, (3) bladder-wall interruption, (4) placental bulge, (5) uterovesical hypervascularity, (6) placental lacunae and (7) bridging vessels. A consensus was not reached for any of the eight new signs identified by the systematic review. With respect to other ultrasound features that are not specific to PAS but increase the probability of PAS at birth, the panelists reached a consensus for the finding of anterior placenta previa or placenta previa with cervical involvement. The experts were also asked to determine which PAS signs should be quantified and consensus was reached only for the quantification of placental lacunae using an existing score. For predicting surgical outcome in patients with a high probability of PAS at delivery, a consensus was obtained for loss of the clear zone, bladder-wall interruption, presence of placental lacunae and presence of placenta previa involving the cervix.

CONCLUSIONS

We have confirmed the continued importance of seven established standardized ultrasound signs of PAS, highlighted the role of transvaginal ultrasound in evaluating the placental position and anatomy of the cervix, and identified new ultrasound signs that may become useful in the future prenatal evaluation and management of patients at high risk for PAS at birth. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Placenta accreta spectrum disorders clinical practice guidelines: A systematic review

OBJECTIVES

To objectively assess the quality of the published clinical practice guidelines (CPGs) on the management of pregnancies complicated by placenta accreta spectrum (PAS)disorders.

METHODS

MEDLINE, Embase, Scopus, and ISI Web of Science databases were searched. The following aspects related to the management of pregnancies with suspected PAS disorders were evaluated: risk factors for PAS, prenatal diagnosis, role of interventional radiology and ureteral stenting, and optimal surgical management. The assessment of risk of bias and quality assessment of the CPGs were performed using the (AGREE II) tool (Brouwers et al., 2010). To define a CPG as of good quality we adopted a cut-off score >60%.

RESULTS

Nine CPGs were included. Specific risk factors for referral were assessed by 44.4% (4/9) of CPGs, mainly consisting in the presence of placenta previa and a prior cesarean delivery or uterine surgery. About 55.6% of CPGs (5/9) suggested ultrasound assessment of women with risk factors for PAS in the second and third trimester of pregnancy and 33.3% (3/9) recommended magnetic resonance imaging (MRI); 88.9% (8/9) of CPGs recommended cesarean delivery at 34-37 weeks of gestation. There was not generally consensus on the use of interventional radiology and ureteral stenting before surgery for PAS. Finally, hysterectomy was the recommend surgical approach by 77.8% (7/9) of the included CPGs.

CONCLUSION

Most of the published CPGs on PAS are generally of good quality. There was general agreement among the different CPGs on PAS as a regard as risk stratification, timing at diagnosis and delivery but not on the indication for MRI, use of interventional radiology and ureteral stenting.

Two-dimensional ultrasound signs as predictive markers of massive peri-operative blood loss in placenta previa suspicious for placenta accreta spectrum (PAS) disorder

OBJECTIVE

To evaluate certain two-dimensional (2D) ultrasound signs as predictors of massive peri-operative blood loss (PBL) in pregnant women with placenta previa suspicious of PAS disorder.

MATERIALS AND METHODS

A single center retrospective study was done in pregnant women who had undergone prenatal diagnosis with 2D ultrasound grey scale and color Doppler using the EW-AIP (which has been changed to IS-PAS (International Society for the Placenta Accreta Spectrum)) criteria between January 2007 and May 2021. The patients were divided into 2 groups, non-massive hemorrhage with PBL ≤ 2500 mL and massive PBL >2500 mL. All PAS cases had pathological confirmation. Ultrasound signs and hemorrhagic outcomes were compared between the two groups. A PAS scoring system to predict massive PBL was constructed and a receiver operating characteristic (ROC) curve was calculated to evaluate the efficacy of the scoring system.

RESULTS

Of 534 women, 146 (28.3%) had PBL > 2500 mL and 388 (71.7%) had PBL ≤ 2500 mL. In the massive PBL group, 101 (69.2%) were diagnosed as PAS and 45 (30.8%) as placenta previa alone. From 10 evaluated 2D ultrasound signs, 3 had the highest odds ratios (ORs) associated with massive PBL, 'focal exophytic mass' OR 8.17 (p = 0.024), 'placental bulge' OR 2.47 (p = 0.011), and 'placental lacunae feeder vessels' OR 2.38 (p = 0.01). When using the PAS scoring system, the AUC to predict massive PBL was 0.80 (95% CI, 0.76-0.85,).

CONCLUSION

Our PAS scoring system based on 2-dimensional ultrasound signs combined with grey scale and color Doppler is useful to predict massive PBL and can help optimize pre-operative management in cases of previa suspicious of PAS.

A practical FIST maneuver to minimize the bleeding during cesarean hysterectomy for placenta percreta: a retrospective comparative study

BACKGROUND

Placenta percreta (PP) is a life-threatening condition and its surgery poses a very high potential for bleeding. The recommended treatment is a cesarean hysterectomy. There are several techniques reported in the literature to reduce the bleeding during percreta operations.

OBJECTIVE

To show and describe a practical and novel intraoperative maneuver to minimize the hemorrhage during cesarean hysterectomy for PP.

METHODS

The patients who were diagnosed with PP and underwent cesarean hysterectomy (CH) in our unit between 2016 and 2020 were retrospectively evaluated. These patients were divided into two groups. Group A included patients who underwent hysterectomy with intraoperative FIST maneuver. Group B included patients with ordinary cesarean hysterectomy. The groups were compared with regards to the intraoperative bleeding, surgical complications, and perioperative outcomes.

RESULTS

Seventy-two patients who had a cesarean hysterectomy and diagnosed with PP during the study period were included in this retrospective cohort. 22 patients underwent intraoperative FIST maneuver with CH as Group A and 50 patients underwent ordinary CH as Group B. The demographic variables including maternal age, gravida, number of previous cesarean sections, and body-mass index were not statistically different between the two groups. Intraoperative FIST maneuver was significantly associated with reduced operative hemorrhage, the need for transfusion of erythrocyte suspension, admission to intensive care unit, and hospitalization days (p < .005). The operative time was statistically significantly shorter in Group A than Group B, respectively (90 ± 18.6 vs 120 ± 20.5 min) (p < .05).

CONCLUSION

FIST maneuver is a very practical, easy to apply, and effective method that reduces the obstetrical bleeding during cesarean hysterectomy in placenta percreta cases.