Placenta percreta invading the urinary bladder and parametrium

Placenta accreta spectrum into the parametrium, morbidity differences between upper and lower location

OBJECTIVE

To demonstrate the surgical and morbidity differences between upper and lower parametrial placenta invasion (PPI).

MATERIALS AND METHODS

Forty patients with placenta accreta spectrum (PAS) into the parametrium underwent surgery between 2015 and 2020. Based on the peritoneal reflection, the study compared two types of parametrial placental invasion (PPI), upper or lower. Surgical approach to PAS follows a conservative-resective method. Before delivery, surgical staging by pelvic fascia dissection established a final diagnosis of placental invasion. In upper PPI cases, the team attempted to repair the uterus after resecting all invaded tissues or performing a hysterectomy. In cases of lower PPI, experts performed a hysterectomy in all cases. The team only used proximal vascular (aortic occlusion) control in cases of lower PPI. Surgical dissection for lower PPI started finding the ureter in the pararectal space, ligating all the tissues (placenta and newly formed vessels) to create a tunnel to release the ureter from the placenta and placenta suppletory vessels. Overall, at least three pieces of the invaded area were sent for histological analysis.

RESULTS

Forty patients with PPI were included, 13 in the upper parametrium and 27 in the lower parametrium. MRI indicated PPI in 33/40 patients; in three, the diagnosis was presumed by ultrasound or medical background. The intrasurgical staging categorizes 13 cases of PPI performed and finds diagnosis in seven undetected cases. The expertise team completed a total hysterectomy in 2/13 upper PPI cases and all lower PPI cases (27/27). Hysterectomies in the upper PPI group were performed by extensive damage of the lateral uterine wall or with a tube compromise. Ureteral injury ensued in six cases, corresponding to cases without catheterization or incomplete ureteral identification. All aortic vascular proximal control (aortic balloon, internal aortic compression, or aortic loop) was efficient for controlling bleeding; in contrast, ligature of the internal iliac artery resulted in a useless procedure, resulting in uncontrollable bleeding and maternal death (2/27). All patients had antecedents of placental removal, abortion, curettage after a cesarean section, or repeated D&C.

CONCLUSIONS

Lower PAS parametrial involvement is uncommon but associated with elevated maternal morbidity. Upper and lower PPI has different surgical risks and technical approaches; consequently, an accurate diagnosis is needed. The clinical background of manual placental removal, abortion, and curettage after a cesarean or repeated D&C could be ideally studied to diagnose a possible PPI. For patients with high-risk antecedents or unsure ultrasound, a T2 weight MRI is always recommended. Performing comprehensive surgical staging in PAS allows the efficient diagnosis of PPI before using some procedures.

Colombian Consensus on the Treatment of Placenta Accreta Spectrum (PAS)

INTRODUCTION

Placenta accreta spectrum (PAS) is a condition associated with massive postpartum bleeding and maternal mortality. Management guidelines published in high income countries recommend the participation of interdisciplinary teams in hospitals with sufficient resources for performing complex procedures. However, some of the recommendations contained in those guidelines are difficult to implement in low and medium income countries.

OBJECTIVES

The aim of this consensus is to draft general recommendations for the treatment of PAS in Colombia.

MATERIALS AND METHODS

Twenty-three panelists took part in the consensus with their answers to 31 questions related to the treatment of PAS. The panelists were selected based on participation in two surveys designed to determine the resolution capabilities of national and regional hospitals. The modified Delphi methodology was used, introducing two successive discussion rounds. The opinions of the participants, with a consensus of more than 80%, as well as implementation barriers and facilitators, were taken into consideration in order to issue the recommendations.

RESULTS

The consensus draftedfive recommendations, integrating the answers of the panelists. Recommendation 1. Primary care institutions must undertake active search of PAS in patients with risk factors: placenta praevia and history of myomectomy or previous cesarean section. In case of ultrasound signs suggesting PAS, patients must be immediately referred, without a minimum gestational age, to hospitals recognized as referral centers. Online communication and care modalities may facilitate the interaction between primary care institutions and referral centers for PAS. The risks and benefits of telemedicine modalities must be weighed. Recommendation 2. Referral hospitals for PAS need to be defined in each region of Colombia, ensuring coverage throughout the national territory. It is advisable to concentrate the flow of patients affected by this condition in a few hospitals with surgical teams specifically trained in PAS, availability of specialized resources, and institutional efforts at improving quality of care with the aim of achieving better health outcomes in pregnant women with this condition. To achieve this goal, participants recommend that healthcare regulatory agencies at a national and regional level should oversee the process of referral for these patients, expediting administrative pathways in those cases in which there is no prior agreement between the insurer and the selected hospital or clinic. Recommendation 3. Referral centers for patients with PAS are urged to build teams consisting of a fixed group of specialists (obstetricians, urologists, general surgeons, interventional radiologists) entrusted with the care of all PAS cases. It is advisable for these interdisciplinary teams to use the “intervention bundle” model as a guidance for building PAS referral centers. This model comprises the following activities: service preparedness, disease prevention and identification, response to the occurrence of the disease, and debriefing after every event. Telemedicine facilitates PAS treatment and should be taken into consideration by interdisciplinary teams caring for this disease. Recommendation 4. Obstetrics residents must be instructed in the performance of maneuvers that are useful for the prevention and treatment of massive intraoperative bleeding due to placenta praevia and PAS, including manual aortic compression, uterine tourniquet, pelvic packing, retrovesical bypass, and Ward maneuver. Specialization Obstetrics and Gynecology programs in Colombia must include the basic concepts of the diagnosis and treatment of PAS. Referral centers for PAS must offer online and in-person training programs for professionals interested in improving their competencies in PAS. Moreover, they must offer permanent remote support (telemedicine) to other hospitals in their region for patients with this condition. Recommendation 5. Patients suspected of having PAS and placenta praevia based on imaging, with no evidence of active vaginal bleeding, must be delivered between weeks 34 and 36 6/7. Surgical treatment must include sequential interventions that may vary depending on the characteristics of the lesion, the clinical condition of the patient and the availability of resources. The surgical options (total and subtotal hysterectomy, one-stage conservative surgical management and watchful waiting) must be included in a protocol known by the entire interdisciplinary team. In situations in which an antepartum diagnosis is lacking, that is to say, in the face of intraoperative finding of PAS (evidence of purple bulging or neovascularization of the anterior aspect of the uterus), and the participation of untrained personnel, three options are considered: Option 1: In the absence of indication of immediate delivery or of vaginal delivery, the recommendation is to postpone the cesarean section (close the laparotomy before incising the uterus) until the recommended resources for safe surgery are secured. Option 2: If there is an indication for immediate delivery (e.g., non-reassuring fetal status) but there is absence of vaginal bleeding or indication for immediate PAS management, a two-stage management is suggested: cesarean section avoiding placental incision, followed by uterine repair and abdominal closure, until the availability of the recommended resources for safe surgery is ascertained. Option 3: In the event of vaginal bleeding that prevents definitive PAS management, the fetus must be delivered through the uterine fundus, followed by uterine repair and reassessment of the situation. Sometimes, fetal delivery diminishes placental flow and vaginal bleeding is reduced or disappears, enabling the possibility to postpone definitive management of PAS. In case of persistent significant bleeding, hysterectomy should be performed, using all available resources: manual aortic compression, immediate call to the surgeons with the best available training, telemedicine support from expert teams in other hospitals. If a patient with risk factors for PAS (e.g., myomectomy or previous cesarean section) has a retained placenta after vaginal delivery, it is advisable to confirm the possibility of such diagnosis (by means of ultrasound, for example) before proceeding to manual extraction of the placenta.

CONCLUSIONS

It is our hope that this first Colombian consensus on PAS will serve as a basis for additional discussions and collaborations that can result in improved clinical outcomes for women affected by this condition. Additional research will be required in order to evaluate the applicability and effectiveness of these recommendations.

Abnormal placentation

The term "morbidly adherent placenta" has recently been introduced to describe the spectrum of disorders including placenta accreta, increta and percreta. Due to excessive invasion of the placenta into the uterus there is associated significant maternal morbidity and mortality. Most significant risk factors for morbidly adherent placenta include history of prior cesarean delivery as well as placenta previa in the current pregnancy. Ultrasound remains the gold standard for antenatal diagnosis, however, in recent years MRI has assisted in identifying complex parametrial involvement. Optimizing maternal and neonatal outcomes involves early prenatal diagnosis, a multi-disciplinary team-based approach, and referral to an experienced center.

Diagnostic accuracy of cystoscopy and ultrasonography in the prenatal diagnosis of abnormally invasive placenta

The aim of this study was to compare the accuracy of cystoscopy and ultrasonography for the prenatal diagnosis of abnormally invasive placenta (AIP), including its subgroups: placenta accreta (PA), placenta increta (PI), and placenta percreta (PP).A retrospective observational study including a total of 85 pregnant women at high risk for AIP underwent prenatal cystoscopy and ultrasonography evaluations. The sensitivity (Se), specificity (Sp), positive predictive value, negative predictive value, and exact diagnosed were calculated and compared for both cystoscopy and ultrasonography. Se and Sp values of cystoscopy and ultrasonography were compared by means of the McNemar test.Of the 85 patients, there were 24 (28.2%) PA, 35 (41.2%) PI, 4 (4.7%) PP, and 22 (25.9%) nonadherent placenta. The mean maternal age and gestational age of delivery were 31.88 ± 4.42 years and 36.14 ± 1.84 weeks, respectively. No one was found to develop any complications with cystoscopy like urinary tract infection, or ureteral injury or perforations. Se in the diagnosis of AIP was 50.8% with ultrasonography and 61.9% for cystoscopy. Sp was 86.4% with cystoscopy and 72.7% for ultrasonography. In subgroups, Se with cystoscopy was 25.0%, 62.9%, and 100.0% in PA, PI, and PP, respectively, and 37.5%, 74.3%, and 100.0%, respectively, for ultrasonography; Sp remained unchanged with 86.4% for cystoscopy and 72.7% for ultrasonography. After McNemar test, no difference was found in either Se or Sp between cystoscopy and ultrasonography in AIP and its subgroups.According to the depth of invasion, the diagnostic value of cystoscopy and ultrasonography is all conspicuous increased and they have similar test validity for prenatal diagnosis of AIP and its subgroups.