Cesarean scar pregnancy: Diagnosis with three-dimensional (3D) ultrasound and 3D power Doppler [2]
Journal
Ultrasound in Obstetrics and Gynecology
Journal Volume
23
Journal Issue
3
Pages
306-307
Date Issued
2004
Author(s)
Abstract
I agree with Jurkovic et al.1 that Cesarean scar pregnancy is not as rare as previously assumed. In our institute, Cesarean scar pregnancy is even more common than cervical pregnancy. Ultrasound diagnosis of Cesarean scar pregnancy has been hampered by technical limitations and the lack of consensus on the diagnostic criteria. Essentially, the diagnosis is established when ultrasound demonstrates that the gestational sac is implanted in the lower segment of the anterior uterine corpus with evidence of myometrial dehiscence. In our institute, we do not routinely perform the cervical pressure test2 during transvaginal examination to exclude incomplete miscarriage since the pressure placed on the cervix may give the patient the mistaken impression that a miscarriage was induced by the procedure. Nevertheless, to avoid a false-positive diagnosis, evidence of peritrophoblastic flow surrounding the trophoblastic shell should be obtained. We report a case of Cesarean scar pregnancy comprehensively diagnosed by three-dimensional (3D) ultrasound with surface-rendered vascular imaging. A 37-year-old woman, gravida 3 para 2, visited our clinic due to persistent lower abdominal pain at 7 weeks of gestation. She had two previous Cesarean deliveries for macrosomia and a repeat section, respectively. Both deliveries had no puerperal complications. Dark-reddish bleeding and dull pain over the lower abdomen were noted shortly after confirmation of this pregnancy. Transvaginal sonography at our clinic depicted a gestational sac located lower than the expected region (fundal cavity). Serum beta-human chorionic gonadotropin (β-hCG) level was 3530 mIU/mL at the initial visit. To determine if the condition was a cervical pregnancy or incomplete miscarriage in the cervical phase another detailed scan was performed using 3D ultrasound equipped with power Doppler (Voluson 730, Medison, Seoul, Korea). During targeted scanning with 3D ultrasound, a gestational sac measuring 18 × 16 mm in diameter with a viable embryo (crown–rump length of 4.5 mm) was visualized in the anterior wall of the uterus. The fundal endometrial cavity was empty, and no fluid was observed in the cul-de-sac. The cervix was 3.4 cm in length. Surface rendering of the uterus through the myometrial dehiscence in the sagittal plane further enabled a precise anatomic delineation between the gestational sac and its implantation area (Figure 1). The gestational sac was embedded at the site of the previous Cesarean scar beneath the uterovesical fold. The gestational sac was neither distorted nor collapsed, which are common observations on 3D ultrasound imaging of miscarriage3. A well-developed trophoblastic shell was identified around the gestational sac. The myometrium between the gestational sac and the bladder wall was very thin. Ballooning of the endocervical canal, which is usually associated with cervical pregnancy, was also absent. 3D power Doppler further depicted peritrophoblastic flow surrounding and entering the well-formed trophoblastic shell (Figure 2). This finding enabled us to exclude incomplete miscarriage in the cervical phase. The diagnosis of Cesarean scar pregnancy was thus established based upon these 3D imaging findings. Cesarean scar pregnancy demonstrated by three-dimensional ultrasound showing the gestational sac implanted in the lower segment dehiscence of the anterior myometrium. In this gestational sac an embryo with its yolk stalk was also seen. A well-developed trophoblastic shell was depicted around the gestational sac. The residual myometrium was thin and bulged into the uterovesical fold (indicated by the arrow). CX, cervix; F, fundal endometrial cavity. Three-dimensional combined mapping of B-mode and power Doppler signals in the same view as that of Figure 1. Peritrophoblastic flow entering the trophoblastic shell was clearly depicted. CX, cervix; F, fundal endometrial cavity. In order to avoid the risk of uterine rupture and hemorrhage the woman was admitted to hospital and underwent an elective termination of the pregnancy. During laparotomy the myometrium and serosa overlying the ectopic sac appeared hyperemic, and bulged out into the uterovesical fold. This discernible appearance made it easy to identify the location of the Cesarean scar pregnancy. Dissection of the serosa was performed together with downward displacement on the bladder. The gestational sac was squeezed out and the placental tissue was removed via a small uterine incision at the site of the previous Cesarean scar. To avoid the possibility of residual trophoblasts being left in situ, the scar tissue was also removed and repaired with a single-layer continuous suture with 1-0 Vicryl. Blood loss was minimal. There were no intra-operative complications and the patient's recovery was uneventful. The specimens were sent for pathological examination. Microscopic examination revealed interstitial trophoblasts within the fibromuscular tissue of the old Cesarean scar. No surrounding endocervical glands were noted. These pathological findings confirmed the diagnosis of Cesarean scar pregnancy. Although medical management has been proposed to treat Cesarean scar pregnancy, some women experienced massive bleeding during the period when serum β-hCG levels are falling4, 5. This was perhaps due to the gestational tissue being firmly adherent to the scar tissue despite methotrexate treatment. According to a recent review, termination of a Cesarean scar pregnancy by either laparotomy or hysterotomy, with repair of the accompanying uterine scar dehiscence, may be the best treatment option6. The application of transvaginal sonography within a few weeks of conception has dramatically reduced the mortality and morbidity rates for ectopic pregnancies. Recent applications integrating views obtained over a region with 3D ultrasound permit better visualization in some situations, and thus allow for a more detailed and accurate diagnosis to be made. A combination of multiplanar views and 3D-rendered images usually enhances our ability to identify subtle anatomic details and allows a comprehensive diagnosis7. We suggest that when a doubt arises in the diagnosis of myometrial dehiscence and Cesarean scar implantation, peritrophoblastic flow surrounding the trophoblastic shell may be further illustrated by 3D power Doppler ultrasound to ascertain the diagnosis. Focused application of these techniques may help avoid or provide early recognition of complications of Cesarean scar pregnancy, such as serious hemorrhage and uterine rupture. J.-C. Shih*, * Department of Obstetrics and Gynecology, National Taiwan University Hospital and National Taiwan University College of Medicine, No. 7, Chung-Shan South Road, Taipei 100, Taiwan, Republic of China
SDGs
Other Subjects
adult; anamnesis; case report; cesarean section scar; clinical feature; diagnostic approach route; diagnostic test; disease course; Doppler echography; ectopic pregnancy; elective surgery; female; human; laboratory test; letter; medical examination; priority journal; three dimensional imaging; treatment outcome; Adult; Cesarean Section; Cicatrix; Female; Humans; Pregnancy; Pregnancy, Ectopic; Ultrasonography, Prenatal
Type
letter