Three‐dimensional sonographic virtual cystoscopy in a case of placenta percreta

Abstract

The three forms of morbidly adherent placenta (MAP), accreta, increta and percreta, are an emerging obstetric challenge, at times resulting in life-threatening bleeding and/or need for peripartum hysterectomy. The increasing incidence of MAP appears to be linked directly to that of Cesarean delivery. Prenatal diagnosis of MAP by means of ultrasound and/or magnetic resonance imaging in high-risk populations is feasible and leads to improved maternal and neonatal outcomes through multidisciplinary planning of delivery1. Of particular importance is the differential diagnosis between placenta percreta and the less severe forms of MAP, i.e. placenta accreta and increta, and it has been shown that this is possible using ultrasound2-4. Preoperative knowledge about the degree of bladder invasion is key to safe and successful surgical management of MAP: in some cases, cystectomy with preoperative insertion of ureteral stents are required. Moreover, in some cases of severe placenta percreta, depending on the degree of bladder invasion, conservative treatment without hysterectomy is feasible. Conventional cystoscopy can identify lesions occupying the full thickness of the bladder wall but does not provide detail on vascularization of the adjacent placental basal layer (Figure 1), the extent of which is related directly to the degree of MAP. In our diagnostic work-up of patients with MAP, we have introduced three-dimensional high-definition flow (3D-HD-flow) ‘sonographic virtual cystoscopy’5 to analyze the vascular topography of the uterine–bladder interface (Figure 2). In this case of placenta percreta, we carried out a targeted 3D-HD-flow transvaginal examination (Voluson E8 Expert machine, GE Medical Systems, Zipf, Austria), with the bladder filled to 300 mL, which we consider optimal for evaluating the uterine–bladder interface. Following volume acquisition, we analyzed the image with glass-body rendering (Figure 2 and Videoclip S1) and were able to determine that the posterior bladder wall was contiguous with the abnormal site of placental insertion. In cases of placenta percreta, visualization of the vascularity within the basal layer of the placenta allows early ascertainment of the degree of myometrial infiltration and involvement of the bladder mucosa. This knowledge is important for scheduling the timing of delivery and the surgical approach. In the management of placenta percreta, we believe that sonographic virtual cystoscopy can complement information provided by conventional cystoscopy. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. The following supporting information may be found in the online version of this article: Videoclip S1 Rotation of a three-dimensional high-definition flow sonographic glass-body rendered volume, showing widespread vascularization of the uterine serosa–bladder interface with intact bladder mucosa in a case of early placenta percreta.