Sonographic Diagnosis and Management With Delayed Hysterectomy of Two Cesarean Scar Pregnancies That Developed Into Placenta Percreta: Two Case Reports

Abstract

Approximately two-thirds of the patients with a cesarean scar pregnancy (CSP) will develop placenta accreta spectrum (PAS). PAS occurs when the placenta attaches too deeply to the uterine wall, and sometimes, the placenta can extend beyond the uterus, invading surrounding organs. PAS is commonly managed with a cesarean hysterectomy, and these deliveries are often complicated by maternal and fetal morbidity and mortality. However, delaying hysterectomy and using chemotherapeutic agents may be a safe and beneficial alternative. We describe the case of a 32 -year-old G3P2002 with a history of two prior cesarean sections (CS) who was referred to our Maternal Fetal Medicine department due to the concern of a gestational sac embedded in the anterior uterine wall in the cesarean scar. Magnetic resonance imaging (MRI) findings at 33 weeks confirmed that the patient had developed placenta percreta extending into the sigmoid colon. We also describe the case of a 30-year-old G6P4104 with a history of four prior CS who was referred to our department for concern of a pregnancy complicated by CSP. This patient had an MRI performed at 23 weeks that showed placenta percreta invading the bladder. Patients one and two were managed with a staged procedure, with CS followed by a delayed laparoscopic and abdominal hysterectomy, respectively, to minimize bowel and bladder injury. After the CS, the patients subsequently received a five-day course of intravenous (IV) etoposide 100mg/m2, and at six weeks postpartum, the patients had a hysterectomy, both showing resolution of the placenta invasion into the surrounding organs on postpartum MRI and confirmed by tissue pathology reports. Our cases present the challenge in diagnosis and management of the most severe presentation of PAS that varies from the generally accepted management recommendations. Delayed hysterectomy with chemotherapy can be a reasonable, conservative surgical approach in the most severe types of PAS. As in our cases, this management could improve maternal and fetal morbidity and mortality.

Keywords: cesarean scar pregnancy; delayed hysterectomy; etoposide; placenta accreta spectrum disorder; placenta percreta.

Figure 1. Transvaginal ultrasound (TVUS) findings at six weeks and three days gestational age (GA)

A: Transvaginal ultrasound (TVUS) at six weeks and three days gestational age (GA) showing a low-lying gestational sac at the location of the cesarean scar (CS) scar with an empty uterine fundus and cervical canal. B: Color Doppler at six weeks and three days GA showing marked peritrophoblastic flow around the gestational sac consistent with cesarean scar pregnancy (CSP).

Figure 2. Transvaginal ultrasound (TVUS) findings at 18 weeks and six days gestational age (GA)

A: Transvaginal ultrasound (TVUS) at 18 weeks and six days gestational age (GA) showing loss of the hypoechoic boundary of the myometrium in the lower uterine segment and placental bulge. B, Color Doppler at 18 weeks and six days GA showing increased vascularity of the uterine serosa-bladder interface.

Figure 3. Sagittal single-shot fast spin echo (SSFSE) (A) and Axial T2 weighted SSFSE (B) Magnetic resonance imaging (MRI) findings at 33 weeks gestational age (GA)

A and B: Magnetic resonance imaging (MRI) at 33 weeks gestational age (GA) showing a focal bulge of the uterus now in contact with the abdominal wall and a loop of the colon with loss of its normal fat plane indicated by the white arrow.

Figure 4. Axial fast imaging with steady-state free precession (FISP) Magnetic resonance imaging (MRI) findings at four weeks postpartum

A and B: Magnetic resonance imaging (MRI) at four weeks postpartum demonstrating an anterior placenta with no evidence of gross extension of the placental tissue through the full thickness of the myometrium. The arrows point at a loop of the small bowel adjacent to the anterior left aspect of the uterine body near the area of the placental wall thickening but do not show any definitive evidence of placental soft tissue extension through the uterine wall to involve this loop of the small bowel.

Figure 5. Transvaginal ultrasound (TVUS) findings in the first and second trimesters

A: Transvaginal ultrasound (TVUS) at eight weeks and five days gestational age (GA) showed a low-lying gestational sac at the location of the cesarean section (CS) scar. B: Anterior placenta previa with multiple placental lakes at 16 weeks and four days GA.

Figure 6. Transvaginal ultrasound (TVUS) findings at 23 weeks and one day gestational age (GA)

A: Anterior placenta previa with placenta lacunae and an irregular bladder line highly suspicious for percreta at 23 weeks and one day gestational age (GA). B: Increased vascularity on Color Doppler transvaginal ultrasound (TVUS) at the uterine-serosa bladder interface at 23 weeks and one day GA.

Figure 7. Sagittal half Fourier acquisition single-shot turbo spin echo (HASTE) Magnetic resonance imaging (MRI) findings at 23 weeks and one day gestational age (GA)

A and B: Magnetic resonance imaging (MRI) at 23 weeks and one day gestational age (GA) confirming placenta previa with findings highly suspicious for placenta percreta. The placenta appears to involve the anterior abdominal wall in the midline, indicated by the white arrow (Image A), and involves the bladder (Image B).

Figure 8. Axial (A) and Sagittal (B) T2 weighted magnetic resonance imaging (MRI) findings at four weeks postpartum

A and B: Follow-up magnetic resonance imaging (MRI) at four weeks postpartum revealed a persistent placenta percreta to the anterior dome of the bladder demonstrated by the arrows.