Placenta percreta is a devastating obstetrical condition, considered one of the severe forms of the placenta accreta spectrum (placenta accreta) or “morbidly adherent placenta”. The worldwide incidence of placenta percreta has increased in the last five years, being influenced by several risk factors, such as: uterine scar after previous uterine surgery, history of placenta accreta, abnormal scarring, maternal age over 35 years old, multiparity, previous resectoscopy, human assisted reproductive technologies, and smoking. Optimal diagnosis involves clinical evaluation of the patient, personal medical history, laboratory tests, as well as ultrasound and magnetic resonance imaging in order to assess the degree of placental invasion into adjacent tissues. Surgical treatment involves a major surgery such as caesarean hysterectomy, the most accepted management option, but there are other methods, including interval hysterectomy, caesarean section with placental abandonment in situ, with or without methotrexate administration. This article presents the case of a 33-year-old patient with uterine pregnancy of 31 weeks + 2 days of amenorrhea and uterine scar after caesarean section in 2019. The patient followed in vitro fertilization, presenting laryngotracheitis, essential hypertension, imminence of premature birth, and complete placenta praevia. Ultrasound signs for placenta praevia and placenta percreta, with signs of placental invasion into the muscular and mucosal layers of the urinary bladder. A multidisciplinary medical team took the decision to finish the pregnancy by elective caesarean hysterectomy.
Placenta percreta este o afecţiune devastatoare, considerată una din formele severe ale spectrului de placentă accreta sau „placentă cu aderenţă morbidă”. Incidenţa ei la nivel mondial a crescut în ultimii cinci ani, fiind influenţată de factori de risc precum: uter cicatricial după intervenţii chirurgicale uterine anterioare, istoric de placentă accreta, cicatrizare anormală, vârsta maternă peste 35 de ani, multiparitatea, rezectoscopie în antecedente, tehnici de reproducere umană asistată şi tabagismul. Diagnosticul optim implică evaluarea clinică a pacientei, alături de antecedentele medicale personale, analize de laborator, precum şi ecografie sau rezonanţă magnetică nucleară, pentru a evalua gradul de invazie a placentei în ţesuturile adiacente. Tratamentul chirurgical implică o intervenţie chirurgicală majoră, cum ar fi histerectomia cezariană, cea mai acceptată opţiune de management, dar sunt şi alte metode, precum histerectomia la interval sau cezariana cu abandonarea placentei in situ, cu sau fără administrarea de metotrexat. Prezentăm cazul unei paciente de 33 de ani, cu sarcină uterină de 31 de săptămâni + 2 zile, cu amenoree şi uter cicatricial după operaţie cezariană în 2019. Pacienta a urmat ferilizare in vitro, prezentând laringotraheită, HTA esenţială, iminenţă de naştere prematură şi placentă praevia completă. Semne ecografice pentru placenta praevia şi placenta percreta, cu semne de invazie în musculară şi în mucoasa vezicii urinare. În mod consultativ, în cadrul unei echipe medicale multidisciplinare, s-a luat decizia de a finaliza sarcina prin histerectomie cezariană electivă.
Placenta percreta is a severe obstetrical condition of the placenta accreta spectrum (PAS), associated with a high rate of maternal morbidity and mortality, and presenting a unique challenge for its diagnosis and management.
The global incidence of PAS and placenta percreta, in particularly, is increasing rapidly in the last five years, attributed to the increasing rate of caesarean sections (CS), as well as the aging of the population(1).
Placenta percreta is a pathological condition in which the placenta attaches and penetrates completely through the uterine wall, ending up invading the urinary bladder or other adjacent organs. The term percretus derives from Latin, meaning “penetrated” or “invaded”. It is considered one of the severe forms of placenta accreta, also known as “morbidly adherent placenta”. Its origin may be associated with abnormal placental development, as well as abnormal implantation in the uterine wall. Placenta percreta is a result of an abnormal decidualization – changes in the decidual tissue of the endometrium near placentation(2).
The etiology of placenta percreta is not completely elucidated, but there are several factors that can contribute to the development of this condition(1,3,4):
Uterine scar after previous uterine surgery, such as caesarean section or others. More than 90% of PAS cases occur in women with at least one previous caesarean delivery, especially in cases with a history of placenta praevia(1).
History of placenta accreta – women who have had previously placenta accreta are at higher risk of developing severe forms such as percreta in subsequent pregnancies.
Abnormal scarring – excessive scarring of the uterus can lead to changes in its structure and integrity, making the uterine wall more fragile and less able to resist placental penetration.
Advanced maternal age – uterine tissue undergoes changes in time, such as loss of elasticity and thinning of the uterine wall, which may affect the ability of the uterus to maintain its integrity and support normal placental implantation.
Multiparity – with each pregnancy and delivery, there is a reduction in uterine vascularization, which can compromise blood flow to the placenta during the next pregnancy and contributing to the development of placenta percreta. As well, multiparity affects the hormonal balance, which influences the development of the placenta.
Hysteroscopy resection of endometrial polyp, myoma, or uterine synechiae.
Human assisted reproductive technologies.
Smoking – tabacco use during pregnancy is associated with changes in placental structure and function, such as increased basement membrane thickness and vascular resistance. Smoking can cause inflammation and oxidative stress, and these inflammatory processes can disrupt the normal development and functioning of the placenta.
Classification. Pathological placental insertion has been classified by Luke et al. into three categories(5,6):
1. Adherent placenta accreta – described by pathologists as “placenta vera, creta or adherent”, when the chorionic villi adhere to the myometrium. In this situation, separation of the placenta from the uterine wall during delivery can be difficult and can lead to postpartum hemorrhage.
2. Placenta increta – when the chorionic villi invade the myometrium, which increases the risk of hemorrhage and the need for surgical interventions to manage the birth.
3. Placenta percreta – when the villi penetrate through the myometrium and uterine visceral peritoneum into the neighboring pelvic organs, most often in the bladder. It is further classified into focal, partial and total, depending on the number of placental cotyledons invaded.
Placenta accreta represents approximately 79% of PAS cases, placenta increta represents 14% of PAS cases, and placenta percreta represents 7% of PAS cases(1).
The term placenta accreta has gradually been replaced by “morbidly adherent placenta”. In classical terminology, any situations in the placenta accreta-increta-percreta spectrum is called placenta accreta spectrum(1).
The diagnosis of placenta percreta involves the following aspects:
Clinical signs – patients with placenta percreta usually present with vaginal bleeding and pain in the lower abdomen. Hematuria as a clinical sign is rare (25%), even in placenta percreta with bladder invasion.
Ultrasound signs – they may vary, depending on the gestational age, the thickness and composition of the placental bed, the number of previous uterine scars, the presence of scar defects between pregnancies, the depth of invasion and the lateral extension of the villous tissue.
Imaging criteria established by Baughman et al. – placenta praevia, lacunae, abnormal color Doppler, loss of retroplacental space, reduced myometrial thickness, irregular bladder wall, turbulent blood flow extending from placenta to neighboring tissues(7).
Magnetic resonance imaging (MRI) characteristics:
Nodular outline of the uterus, rounded edges, uterine bulging, placenta praevia.
Parenchymal heterogeneity, presence of dark, irregular and thick intraplacental bands.
Thickness gap between placental tissue and adjacent pelvic organs.
Placental sign disrupting the hypointense line of the urinary bladder.
Affected area of the trigone, the urinary bladder, and the ureter(8).
Management. Worldwide, there are many discussions regarding the management of placental insertion disorders, with some centers opting for a radical approach, others for a conservative management.
The American College of Obstetricians and Gynecologists (ACOG) and the Royal College of Obstetricians and Gynaecologists (RCOG) have published guidelines with evidence-based approaches regarding clinical management. According to them, the rate of success and outcome of each procedure is directly related to the degree of depth and lateral placental invasion. There are limited cases of bladder invasion.
If a premature birth is predicted, the doctor may indicate the corticosteroids administration for the prophylaxis of respiratory distress syndrome. It is recommended to avoid an urgent caesarean section and to opt for an elective delivery at 35-36 weeks of gestation, or less than 34 weeks in case of recurrent episodes of vaginal bleeding(8,9).
The optimal management of placenta percreta invading the urinary bladder still remains controversial, due to the lack of prospective randomized controlled studies regarding the treatment and long-term outcomes.
Preoperatively, depending on bladder invasion and the risk of hemorrhage, the obstetrician and interventional radiologist may choose to perform balloon occlusion, ligation, or embolization of the internal iliac artery, bilaterally. Bilateral placement of the ureteral catheter can be done depending on the area of bladder wall involvement and the proximity of the ureteral opening(10).
Surgical treatment involves a major surgery such as caesarean hysterectomy, the most accepted management option, but there are other methods accepted, like interval hysterectomy, caesarean section with placental abandonment in situ, with or without methotrexate administration.
Subtotal or total hysterectomy is necessary in order to control the bleeding and to reduce the risk of further complications. In severe cases, where the placenta invades neighboring organs, excision or resection of the affected tissues may be necessary(2,12). In the case of an interval hysterectomy, the risks outweigh the benefits, thus elective caesarean hysterectomy is recommended(9,12).
Expectant management with placental abandonment in situ and waiting for its resorption is an alternative method, especially if the patient wishes to preserve her reproductive function. It is associated with risks such as massive bleeding, infections, fistula, and the need for an emergency hysterectomy. The adjunctive therapy in expectant management is the administration of methotrexate to accelerate placental resorption. It is important to take into consideration the methotrexate risks association, such as the impairment of the blood’s coagulation capacity, thus increasing the risk of hemorrhage; it can cause tissue necrosis of placental tissue, as well as adjacent tissue, and it reduces the body’s ability to fight infections and may cause systemic adverse reactions(11).
Case report
A 33-year-old patient was admitted to the “Gheorghe Paladi” Clinical Municipal Hospital, Chişinău, the department of pregnancy’s pathology, on 20.02.2024, with the diagnosis: uterine pregnancy 31 weeks + 2 days. Pregnancy – V. Births – 2. Complicated obstetrical anamnesis – uterine scar after CS in 2019. Complicated gynecological anamnesis – three ectopic pregnancies. In vitro fertilization. Laryngotracheitis. Essential hypertension. Imminence of premature birth. Complete placenta praevia (confirmed at ultrasound on 29.01.2024).
The patient complained of bloody vaginal discharge. During gynecological examination with valves, it was visualized an eccentric, long, closed cervix. Moderate bloody vaginal discharge.
The ultrasound performed on 21.02.2024 confirmed the diagnosis of 31-week, monofetal pregnancy, normal fetal morphology for the age, complete placenta praevia, and attested placenta percreta. Ultrasound signs for placenta praevia percreta – increased volume with multiple transonic lacunae, with signs of invasion into the muscular and mucosal layer of the urinary bladder.
Paraclinical performed examinations
General blood analysis: hemoglobin 95 g/l; erythrocytes 3.1x1012/l; color index 0.9x109/l; leukocytes 12.6x109/l; hematocrit 0.28; platelets 278x109/l.
General analysis of urine – color: yellow; density 1022; reaction: acid; glucose: weakly positive; transparency slightly cloudy; protein 0.033; epithelium: few; leukocytes 3-4; erythrocytes 1-2; mucus: little; bacteria: +.
The management decision was to finish the pregnancy by elective caesarean hysterectomy. The planned anesthetic management was general anesthesia. The patient was informed and counseled about the possible complications. The informed consent was obtained. The blood transfusion department was notified, and there were ordered red blood cell concentrate and plasma. The multidisciplinary team included three experienced obstetricians, one urologist, one vascular surgeon, and anesthesiologists.
The caesarean hysterectomy intervention was divided into several stages.
Surgery protocol (22.02.2024 – 09:24-11:10): median laparotomy. Elective caesarean section through corporal-fundal incision. Peripartum subtotal hysterectomy.
Under general anesthesia, a Bakri catheter was placed intravaginally, with compressive-hemostatic purpose.
Step 1. Median laparotomy and hysterotomy
After operative field preparation, through a median incision, the abdominal cavity was opened on anatomical layers, in the wound it was visualized the pregnant uterus, on the anterior uterine wall, and in the lower segment there were detected a pronounced vascular pattern, purple vascular lacunae, jellyfish appearance. The uterus was exteriorized in the wound, and a corporal-fundal incision was made to avoid the placenta.
Step 2. Large hysterotomy for atraumatic fetal extraction and diathermy to prevent blood loss. Clear amniotic fluid. At 09:27, a live male fetus was extracted, with weight 1800 g and Apgar score of 7 points at 5 minutes.
Step 3. Clamping and immediate sectioning of the umbilical cord. Fenestrated forceps are applied along the incision route.
Step 4. Urinary bladder separation and subtotal hysterectomy.
Forceps and counter forceps were applied to the round ligament, ovarian ligament, fallopian tubes, bilaterally incised and sutured. There were applied Fiodorov forceps on the uterine rim, and the uterine arteries were incised and sutured.
On the posterior wall of the urinary bladder, it was visualized an area of 5x5 cm of the invasion of the chorionic villi up to the mucosa (figure 6). Through fine movements, the urinary bladder was detached from the anterior wall of the uterus with simultaneous coagulation of the vessels.
A circular incision was made at the level of the uterine isthmus, inferior to the placental invasion, and the uterus with the placenta in situ was removed. At the uterine abutment, separate sutures with vicryl were applied. The peritonization was performed continuously with vicryl from the vesicouterine envelope.
Step 5. Hemostasis control
Intraoperative bleeding was balanced by blood product replacement and antifibrinolytic therapy. Intraoperatively, there were administered erythrocyte concentrate (1425 ml) and plasma (2250 ml). Total bleeding: 4000 ml.
Step 6. Peritoneal “toilet” and laparoraphy on anatomical layers. A drain was placed in the abdominal cavity. On the skin: intradermal vicryl suture. The postoperative period was uneventful.
Postoperative diagnosis: uterine pregnancy of 31-32 weeks. Uterine scar after caesarean section. In vitro fertilization. Essential hypertension. Nasopharyngitis. Placenta praevia complete (IV grade). Placenta percreta with invasion of the urinary bladder mucosa.
Discussion
Placenta praevia percreta is a devastating condition due to the potential for massive hemorrhage, leading to essential maternal morbidity, even maternal mortality.
Prenatal diagnosis of placenta percreta is essential for devising optimal management and treatment for the patient. It is very important to make a differential diagnosis between placenta accreta, increta and percreta.
The appropriate diagnosis involves the patient’s clinical evaluation, personal medical history, laboratory tests, as well as ultrasound, color Doppler ultrasound and nuclear magnetic resonance to assess the degree of invasion of the placenta into adjacent tissues.
Because this condition is associated with increased risks, the management requires a multidisciplinary approach involving obstetrician-gynecologists, vascular surgeons, urologists, anesthesiologists, and other doctors from other fields, as needed.
Depending on the severity, the medical team must develop an individualized plan.
Complex treatment involves:
1. Careful monitoring and early prenatal diagnosis in order to be able to properly plan the intervention.
2. Planed delivery – there are several alternative methods, but the most optimal remains the elective caesarean hysterectomy. In some cases, it is possible the surgical removal of the placenta and affected tissues, without removing the uterus, but with uterine reconstruction when preserving reproductive function is needed.
3. Hemodynamic rebalancing and management of complications – the patients may require blood transfusions to manage massive bleeding.
4. Psychological care and emotional support are important for the patient.
The prognosis is reserved, as the risk of complications is increased. Severe bleeding can be life-threatening for the mother, as the risk of uterine rupture is increased due to the invasion of the placenta into the uterine muscle and weakening its structure. Other postoperative complications, such as infections, hemorrhage or damage to adjacent organs, can be seen. There is an increased risk for the fetus as well, because placenta praevia percreta can affect blood flow to the fetus, leading to premature birth or intrauterine growth failure.
Conclusions
Placenta praevia percreta is an aggressive condition that endangers the life of the mother, therefore these cases must be solved in highly experienced medical centers. The management of placenta praevia percreta involves complex approaches and multidisciplinary teams to ensure maternal and fetal safety. Early prenatal diagnosis, planned preoperative actions, and the management of intraoperative and postoperative complications are decisive for the favorable outcomes of this condition.
This work is permanently accessible online free of charge and published under the CC-BY.
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