Case Report: Anaesthetic Management of Placenta Percreta

Background: The placenta is a complicated organ and is partially understood. It is the essential part for physiological changes leading to a successful pregnancy. Placenta percreta is the most severe and least common form of placenta accreta in which villi penetrate the entire myometrial thickness and reach or traverse the serosa to encroach adjacent organs. Patients with placenta percreta are at a greater risk of life-threatening perioperative bleeding as well as massive and deadly thromboembolic events. Case report: Our patient was a 34-year-old gravida 5female who underwent elective cesarean section at 37 weeks of gestation with a diagnosis of placenta accreta or percreta. Intraoperative findings showed placenta percreta with bladder wall involvement. Hence, hysterectomy was done. Anticipated intraoperative haemorrhage and hemodynamic instability were managed properly. Discussion: Placenta percreta is the most serious among abnormal placentation, sometimes leading to catastrophic blood loss and very high maternal mortality and morbidity up to 10%. The most important risk factor in placenta percreta is placenta previa (low lying placenta) after cesarean delivery. Our patient met all these risk factors. Prenatal diagnosis of an invasive placenta is paramount for reducing maternal morbidity and mortality by implementing a multidisciplinary approach. Keywords: haemorrhage, placenta percreta, hysterectomy, high-risk pregnancy.

Placenta Percreta Presents with Neoangiogenesis of Arteries with Von Willebrand Factor-Negative Endothelium

In placenta percreta cases, large vessels are present on the precrete surface area. As these vessels are not found in normal placentation, we examined their histological structure for features that might explain the pathogenesis of neoangiogenesis induced by placenta accreta spectrum disorders (PAS). In two patients with placenta percreta (FIGO grade 3a) of the anterior uterine wall, one strikingly large vessel of 2 cm length was excised. The samples were formalin fixed and paraffin-embedded. Gomori trichrome staining was used to evaluate the muscular layers and Weigert-Van Gieson staining for elastic fibers. Immunohistochemical staining of the vessel endothelium was performed for Von Willebrand factor (VWF), platelet endothelial cell adhesion molecule (CD31), Ephrin B2, and EPH receptor B4. The structure of the vessel walls appeared artery-like. The vessel of patient one further exhibited an unorderly muscular layer and a lack of elastic laminae, whereas these features appeared normal in the vessel of the other patient. The endothelium of both vessels stained VWF-negative and CD31-positive. In conclusion, this study showed VWF-negative vessel endothelia of epiplacental arteries in placenta accreta spectrum. VWF is known to regulate artery formation, as the absence of VWF has been shown to cause enhanced vascularization. Therefore, we suppose that PAS provokes increased vascularization through suppression of VWF. This process might be associated with the immature vessel architecture as found in one of the vessels and Ephrin B2 and EPH receptor B4 negativity of both artery-like vessels. The underlying pathomechanism needs to be evaluated in a greater set of patients.

Cesarean Hysterectomy for Placenta Previa Accreta Using Retrograde Abdominal Hysterectomy Approaching from the Posterior Vaginal Wall

Hysterectomy for placenta percreta with bladder invasion is a difficult operation because of the high possibility of massive bleeding; therefore, surgery should be performed in a facility equipped with a sufficient number of trained staff. The degree of bladder invasion should be assessed correctly before the operation, and it is necessary to carefully consider how to address intraoperative complications and massive bleeding in the preoperative conference. The following should be prepared preoperatively: autologous blood and stored blood; ureteral catheter and insertion materials; materials to separate and tape the internal iliac artery and ureter; balloon for insertion into the common iliac artery or aorta and aortic clamps; and materials for compression suturing, such as B-Lynch suture. Sufficient informed patient consent is also required. During surgery, which may cause massive and sometimes life-threatening bleeding, the general rule is to begin at a safe site without adhesions and then treat the adhesion site. According to this rule, bladder dissection should be performed last in cases of placenta percreta with bladder invasion. As a surgical technique using this principle, we introduce retrograde hysterectomy approaching from the posterior vaginal wall.