Keywords
placenta accreta - prenatal ultrasonographic diagnosis - surgical procedure - blood
transfusion
Introduction
Placenta accreta spectrum (PAS) is a condition associated to massive hemorrhage and
polytransfusion,[1] and patients should be cared for by interdisciplinary groups in experienced centers.[2]
[3]
[4] However, the participation of these expert groups relies on a prenatal diagnosis
that enables the patient to be guided towards this type of care. The frequency of
cases of PAS not diagnosed before laparotomy is variable, but it can be as high as
50%.[5]
[6] In Nicaragua, among the factors that contribute to the low rate of prenatal diagnoses
are the difficulties in training to identify PAS, the absence of centers with a high
influx of patients, and the lack of feedback between the centers that carry out the
diagnosis and those who deliver treatment. The present work describes the clinical
results of the PAS patients managed at a Central American public hospital and the
importance of establishing a prenatal diagnosis.
Materials and Methods
A retrospective analysis of medical records was carried out in search for patients
with PAS treated at Hospital Bertha Calderón Roque, in Managua, Nicaragua, between
June 2017 and December 2021. The diagnostic criteria used was those of the International
Federation of Gynecology and Obstetrics (Fédération Internationale de Gynécologie
et d'Obstétrique, FIGO, in French).[7] The population was divided into patients with a prenatal PAS diagnosis by ultrasound
submitted to surgery for that reason (group 1) and patients in whom PAS was only detected
at the time of the caesarean section (group 2). During this period, the management
protocol was standard, with no variations. All patients with a diagnosis of PAS underwent
cesarean section at 35 weeks, with a plan for total hysterectomy after extraction
of the fetus through the uterine fundus. Specific vascular control strategies nor
ureteral catheters were used. All patients included had placenta previa and underwent
cesarean hysterectomy, same surgical technique was applied. The present retrospective
study was approved by the Institutional Review Board/Ethics Committee for Biomedical
Research (under no. 1494). A descriptive statistical analysis was carried out; The
continuous variables were expressed as median and interquartile range (IQR) values,
and they were analyzed using the Mann-Whitney U test. The qualitative variables were
expressed as absolute and relative frequencies, and the comparison between them was
made using the Chi-squared test or the Fisher exact test according to the case. Statistical
significance was defined as p < 0.05. The analyses were performed using the STATA (StataCorp LLC, College Station,
TX, United States) software, version 14.
Results
During the study period, 114 women with a histological and/or clinical diagnosis of
PAS were found: 51 patients had a prenatal PAS diagnosis by ultrasound (group 1),
and 63 were only diagnosed when they underwent laparotomy (group 2).
[Chart 1] summarizes the clinical results of both groups, showing a lower frequency of transfusions
in group 1 (56.9% versus 87.3% in group 2), as well as the use of a lower number of
red blood cell units (RBCUs) in said transfused patients (median: 1; IQR: 0–4 versus
median: 3; IQR: 2–4 in group 2). The frequency of 4 or more RBCU transfusions was
also lower in group 1 (29.4% versus 44.4% in group 2). Group 2 underwent surgery at
a higher gestational age (mean: 38 weeks; IQR: 35–39 weeks versus median: 34 weeks;
IQR: 32–36 weeks in group 1), with a lower rate of participation of interdisciplinary
groups (62.4% versus 90.2% in group 1) and of elective surgeries than group 1 (22.2%
in group 2 versus 78.4% in group 1). Group 1 also exhibited a non-significant trend
toward a lower volume of blood loss (median: 1,000 mL; IQR: 750–2,000 mL versus median:
1,500 mL; IQR: 1,300–2,200 mL in group 2), lower requirement of pelvic packing with
compresses to control bleeding (1.9% versus 7.9% in group 2), surgical reinterventions
(11.8% versus 17.5% in group 2), and surgical site infection (1.9% versus 4.8% in
group 2) than group 2. In a high percentage of patients (35; 30.9%), the histological
diagnosis was not available because the tissue had not been not processed by the pathology
department.
Chart 1
Comparison of the clinical results of PAS patients with and without a prenatal diagnosis
|
Group 1 (n = 51): WITH prenatal diagnosis
|
Group 2 (n = 63): WITHOUT prenatal diagnosis
|
p-value
|
|
Gestational age at surgery (in weeks)*
|
34 (32-36)
|
38 (35-39)
|
0.003
|
|
Surgical time (in minutes)*
|
103 (82-145)
|
94 (74-129)
|
0.235
|
|
Interdisciplinary group participation: n (%)
|
46 (90.2)
|
33 (62.4)
|
0.003
|
|
Elective surgery: n (%)
|
40 (78.4)
|
14 (22.2)
|
0.002
|
|
Bleeding volume (mL)*
|
1000 (750-2000)
|
1500 (1300-2200)
|
0.347
|
|
Transfusions: n (%)
|
29 (56.9)
|
55 (87.3)
|
0.005
|
|
Number of RBCUs transfused
|
1 (0-4)
|
3 (2-4)
|
0.027
|
|
4 or more RBCUs: n (%)
|
15 (29.4)
|
28 (44.4)
|
0.039
|
|
Bladder injury: n (%)
|
7 (13.7)
|
9 (14.2)
|
0.923
|
|
Ureteral injury: n (%)
|
2 (3.9)
|
0
|
−
|
|
Urinary fistula: n (%)
|
0
|
1 (1.6)
|
−
|
|
Pelvic packing with compresses: n (%)
|
1 (1.9)
|
5 (7.9)
|
0.380
|
|
Reintervention: n (%)
|
6 (11.8)
|
11 (17.5)
|
0.996
|
|
Wound infection: n (%)
|
1 (1.9)
|
3 (4.8)
|
0.666
|
|
Death: n (%)
|
1 (1.9)
|
1 (1.6)
|
0.104
|
|
Histological analysis: n (%)
|
Placenta acreta
|
24 (47.1)
|
34 (53.9)
|
0.890
|
|
Placenta increta
|
11 (21.6)
|
6 (9.5)
|
|
Placenta percreta
|
2 (3.9)
|
2 (3.2)
|
|
No histological study
|
14 (27.4)
|
21 (33.3)
|
Abbreviations: PAS, placenta accreta spectrum; RBCU, red blood cells unit.
Note: *Median (interquartile range).
Discussion
Less than half of our cases (44.7%) had a prenatal PAS diagnosis (group 1). Patients
in group 1 had a lower frequency of transfusions and those among them who received
blood components required a lower number of RBCUs. Although some expert groups have
reported excellent performance of the PAS ultrasonographic diagnosis,[8]
[9] even in some high-income countries the frequency of false positives is close to
that observed in the Nicaraguan population, with a rate of intraoperative diagnosis
close to 50%.[5]
[6] There are multiple factors that explain a poor performance in establishing a PAS
prenatal diagnosis in our population. Although all the patients included in the present
study underwent prenatal follow-up visits and periodic ultrasonographic scans, Nicaragua
has not established protocols to diagnose PAS. Additionally, there are few maternal-fetal
medicine specialists or prenatal ultrasonography experts. Finally, there is no chair
in the diagnosis and treatment of PAS in the obstetrics training programs in our country.
It is important to point out these difficulties as the first step towards improving
the prenatal identification of PAS. It is likely that the knowledge of a prenatal
PAS diagnosis in group 1 facilitated the scheduling of the surgical procedure, which
was elective in 78.4% of these patients, unlike group 2, in which it was elective
in 22.2% of the cases, and at a higher gestational age (median: 34 weeks; IQR: 32–36
weeks in group 1 versus median: 38 weeks; IQR: 35–39 weeks in group 2).
One of the advantages of knowing the PAS diagnosis is the possibility of “scheduling”
the participation of the interdisciplinary groups during surgery.[10]
[11]
[12] Our hospital does not have an interdisciplinary group dedicated to the treatment
of PAS (a “PAS team”); however, patients from group 1 were treated by the more experienced
surgeons available, which included the urologist and the teneral surgeon on duty that
day. This was possible in 90.2% of the cases in group 1, and only in 62.4% of the
cases in group 2. In the event that the diagnosis of PAS was a “surprise” during the
laparotomy, calling the surgeon and the urologist on duty was left at the discretion
of the obstetricians in charge of the surgery. Other authors[5] have pointed out the importance of prenatal diagnosis and its relationship with
lower levels of blood loss and lower use of transfusions, and they also coincide in
documenting important differences in the management of patients with and without a
prenatal diagnosis.
Our hospital is a reference center for the most critical obstetric conditions in the
country, but like many other hospitals with similar characteristics, it does not have
a PAS team.[13] Our flaws in the prenatal diagnosis (intraoperative finding of PAS in 55.2% of our
cases) and histological analysis (absence of analysis by a pathologist in 35 cases)
result in an opportunity to improve the quality of care in our center.
The present study has limitations. Its retrospective design makes it more susceptible
to bias. The absence of histological confirmation in 30.7% of the cases enabled the
inclusion of non-PAS cases; however, patients whose medical record described macroscopic
findings compatible with the FIGO definition were included. The present is the first
evaluation of the clinical results of PAS management in Nicaragua, and one of the
few that have been carried out in Central America.
The results shed light on the need to design improvement plans at the national level,
with the need for multicenter prospective studies to confirm our observations and
evaluate the effect of interventions already implemented, such as the creation of
a PAS team that is provided with specific training in the management of this disease,
the proposal of including PAS screening in routine prenatal care appointments for
women with risk factors, and the project of including a section about PAS in the national
guidelines for the treatment of postpartum hemorrhage.
Conclusion
The presence of a prenatal diagnosis of PAS is related to a lower frequency of RBCU
transfusions. We observed a high frequency of failures within the prenatal PAS diagnostic
steps. It is a priority to improve the prenatal detection of this disease.
