279jum1263online.qxp:Layout 1 8/11/08 10:54 AM Page 1375 Case Report Postpartum Management of Placenta Previa Accreta Left In Situ Role of 3-Dimensional Angiography Orli Langer Most, MD, Tomer Singer, MD, Irving Buterman, MD, Ana Monteagudo, MD, Ilan E. Timor-Tritsch, MD P lacenta previa accreta may require hysterectomy because of the potential of massive obstetric hemorrhage. Overall, up to 92% of women require blood transfusion when traditional surgical management is used.1 Hysterectomy may not be sought as a viable option for women requesting to preserve future fertility. Conservative management by leaving the placenta in utero and administration of methotrexate has been described in the literature. With the use of conservative management, the overall transfusion rate may be lowered substantially but still may be as high as 80%.1 The problem faced at the conclusion of such management is when to proceed with removal of the placenta. This case report illustrates a new and objective way to determine when it is safest to surgically remove the placental tissue without the risk of excess bleeding in hopes of preserving reproductive function. The means to achieve this goal was the use of 3-dimensional (3D) power Doppler angiography to follow the receding blood vessels to the placenta by quantifying its amount of vascularization. Abbreviations 3D, 3-dimensional Received July 30, 2007, from the Division of Obstetric and Gynecologic Ultrasound, Department of Obstetrics and Gynecology, New York University School of Medicine, New York, New York USA. Revision requested August 22, 2007. Revised manuscript accepted for publication May 22, 2008. Address correspondence to Ilan E. TimorTritsch, MD, Division of Obstetric and Gynecologic Ultrasound, Department of Obstetrics and Gynecology, New York University School of Medicine, 550 First Ave, NBV-9E2, New York, NY 10016 USA. E-mail: [email protected] Case Report The patient was a 32-year-old woman with a history of a previous cesarean delivery who in the subsequent pregnancy had a sonographic diagnosis of a fetal limb–body wall anomaly and placenta previa accreta at her 19-week anatomic survey. Transabdominal and transvaginal sonography showed an enlarged and dysplastic placenta with a “Swiss cheese” appearance. The placental vessels appeared to invade through the thin myometrium anteriorly to the wall of the urinary bladder but not through it. Multiple placental lakes were noted throughout the entire placental tissue and the upper part of the cervix. © 2008 by the American Institute of Ultrasound in Medicine • J Ultrasound Med 2008; 27:1375–1380 • 0278-4297/08/$3.50 279jum1263online.qxp:Layout 1 8/11/08 10:54 AM Page 1376 Postpartum Management of Placenta Previa Accreta Left In Situ After informed consent, including risks, benefits, and alternatives, termination of pregnancy by high vertical hysterotomy was performed at 20 weeks’ gestation. The decision was made to shorten the cord to its insertion and leave the placenta in situ and to attempt conservative management. To visualize vascularization, 3D angiographic imaging (Voluson 730 Expert; GE Healthcare, Milwaukee, MI) was added as part of the monthly monitoring of the placental volume. Vascularization was determined in the following fashion: 3D volumes were acquired with color Doppler imaging at 5 to 9 MHz with gain set at 4, the notion filter set at 1, and a pulse repetition frequency of 0.6 KHz. The volumes were analyzed offline with the 4D View version 5.3 laptop computer–based software package (GE Healthcare). Vascularity assessment was done on the basis of the following 3D vascularity indices: the vascularization index, which measures the ratio of color voxels over the total gray and color voxels in an outlined volume (virtual organ computer-aided analysis software; GE Healthcare) and practically represents the percentage of vessels in a region of interest; the flow index, which is proportional to the mean intensity of the color voxels compared to the total number of color voxels, indicating the average intensity of blood flow; and the vascularization-flow index, which indicates the mean color value in all gray and color voxels within the volume, representing a combination of both the flow index and vascularization-flow index and measuring tissue perfusion. The last two are relative numbers on a scale of 0 to 100. Figure 1 shows the process of obtaining the quantitative evaluation of vascularity in the placenta, and Figure 2 shows a 3D angiographic rendering of placental vessels during 3 months of observation. When subjectively almost no power Doppler flow signals were seen at the lowest pulse repetition frequency settings, that observation was used to determine cessation of blood flow to the placenta. To facilitate reduction of the placental mass, the patient received methotrexate intramuscularly. Clinical, laboratory, and sonographic data are summarized in Table 1. 1376 Figure 1. Three-dimensional images obtained 1 month after hysterotomy. A, The placental volume is 399 cm3. The bottom right box is the “cut out” and rendered shape of the placenta in situ. B, Rendering of the placental vascularization by 3D angiography is shown in the bottom right box. This is a qualitative expression of blood flow within the placenta in situ. C, Histogram generated by the virtual organ computeraided analysis software expressing the flow indices. A B C J Ultrasound Med 2008; 27:1375–1380 279jum1263online.qxp:Layout 1 8/11/08 10:54 AM Page 1377 Langer Most et al After a little more than 4 months of conservative management, the vascularization gradually diminished to a minimum (Figure 3) considered low enough to enable a minimal-risk surgical procedure. At this time, dilation and curettage was performed for an uncomplicated and relatively easy removal of the placental mass. Figure 2. Gradual decrease in the vascularization of the placenta after hysterotomy, as followed by 3D power Doppler angiography. A, After 2 months. B, After 3 months. C, After 4 months. A B C J Ultrasound Med 2008; 27:1375–1380 The patient was counseled that precautions and close monitoring would be necessary for future pregnancies. She conceived again 4 months after the surgical procedure and obviously was evaluated for a possible recurrence of the placenta previa accreta. However, the posterior placenta appeared normal. The patient subsequently gave birth to a healthy and viable full-term neonate by cesarean delivery without any placental abnormalities. Discussion Placenta accreta is defined as an abnormal attachment of the placenta to the myometrium and occurs at an incidence of 1 per 5332 to 1 per 70003 deliveries. Risk factors for placenta accreta include a history of cesarean delivery, prior curettage, uterine instrumentation, multiparity, and placenta previa in the current pregnancy. Miller et al4 studied 155,670 deliveries and found placenta accreta incidence rates of 9.3% in women with placenta previa and 0.004% in women without placenta previa. The risk of having placenta accreta in the presence of placenta previa varies from 2% in women with no previous cesarean deliveries, to 24% in women with 1 previous cesarean delivery, to 67% in women with 3 or more previous cesarean deliveries.5 Because placenta accreta is associated with potentially lifethreatening hemorrhage and an average blood loss at delivery of 3000 to 5000 mL,5 it is important to make an early and accurate diagnosis to allow for management, treatment, and reduction of associated morbidity. This diagnosis can be made prenatally by sonography or magnetic resonance imaging. Since the introduction of transvaginal sonography for diagnosing placenta previa6,7 and the pathologically adherent placenta8,9 with gray scale and color or power Doppler imaging, it has become relatively easy to diagnose pregnancies with the above-mentioned conditions. More challenging cases may require repeated sonographic examinations later in gestation or magnetic resonance imaging, mainly for posterior placentas. Sonographic findings suggestive of placenta accreta include irregularly shaped placental lacunae, myometrial thinning in the area over the placenta, bulging of the placenta 1377 279jum1263online.qxp:Layout 1 8/11/08 10:54 AM Page 1378 Postpartum Management of Placenta Previa Accreta Left In Situ into the bladder, increased vascularity at the bladder border, and possible increased vascularity in the lacunae (shown on Doppler sonography). Comstock10 described the presence of placental lacunae as the most predictive sonographic determinant of placenta accreta and described an increasing risk of placenta accreta with an increasing number of lacunae noted on sonography. The goal of treatment for placenta accreta is to achieve the least possible blood loss for the patient. Traditionally, it has involved total abdominal hysterectomy without an attempt to detach the placenta to avoid massive hemorrhage. Because hysterectomy eliminates future fertility and may also be associated with multiple complications and surgical risks to the patient, conservative management of placenta accreta is sometimes desired. The placenta is left in situ, and additional treatment such as methotrexate11,12 or uterine embolization of the pelvic vessels13,14 is given. Alternatively, Kayem et al1 left the placenta in situ and followed with serial sonographic examinations, blood cell counts, and clinical examinations without the use of adjunctive treatment and found a reduction in the hysterectomy rate, transfusions needed, and disseminated intravascular coagulation. Three-dimensional color and power Doppler angiography enables a simultaneous display of gray scale and color flow images while the Doppler or power Doppler mode is on.15 This enables a display of vessels within certain designated volumes such as the fetal kidneys and other vital organs.16,17 Furthermore, it allows evaluation of the vascular anatomy and possible detection of organ perfusion. Previous studies18,19 have described the use of 3D color and power Doppler imaging in assessment of the fetal cardiovascular system. In a real-time approach using Doppler video images, Downey and Fenster19 concluded that power Doppler data were better than color Doppler data for restoration of 3D images. They further noted that power Doppler imaging is a less expensive modality that allows good visualization of both larger and smaller vessels without the need for a contrast medium. Our conservative approach of adding 3D angiographic imaging to a traditional serial sonographic evaluation of the vascularization indices increased the accuracy of placental mass and blood supply evaluations. We found 3D angiography to be instrumental in assessing the connection of the feeding vessels to the placenta to determine the proper timing for its removal. Because conservative management of placenta previa accreta to preserve future fertility is a relatively new concept, extensive patient counseling and discussion regarding risks, benefits, and alternatives are required. We think that this innovative management of placenta previa accreta left in situ could benefit women requesting conservative management for potential future fertility. Table 1. Summary of Clinical Information Over Time Time After Hysterotomy 2 1 2 3 4 3 3 wk mo mo mo mo wk after D&C mo after D&C Placental, Volume, cm3 638 528 362 217 85 POC Normal Uterine Size, cm 18 16 12 13 10 9 8 × × × × × × × 13 × 12 12 × 10 9.5 × 10 7×8 8×7 5×4 5×4 VI Vascularity Indices FI 24.6 49.7 17.3 42.3 20 42.3 12.4 39.5 0.19 18.9 No appreciable flow No appreciable flow VFI 8.2 7.3 4.3 1.3 0.5 β-hCG, mIU/mL (IRP) 5470 3900 ND ND 9.7 ND ND D&C indicates dilation and curettage; FI, flow index; hCG, human chorionic gonadotropin; IRP, international reference preparation; ND, not determined; POC, products of conception; VFI, vascularization-flow index; and VI, vascularization index. 1378 J Ultrasound Med 2008; 27:1375–1380 279jum1263online.qxp:Layout 1 8/11/08 10:54 AM Page 1379 Langer Most et al Figure 3. Three weeks after hysterotomy, the placenta is in place, as shown on 2-dimensional imaging. A, Gray scale longitudinal section showing the empty cavity, which is the placenta (arrows). CX indicates cervix. B, Power Doppler image showing the intensive blood supply to the placenta. C and D, Gray scale and color Doppler images of the placenta in situ 3 months after hysterotomy. E and F, Gray scale and power Doppler images of the placenta in situ 4 months after hysterotomy. Note the absence of flow in F. Ut-W indicates uterine width. A B C D E F J Ultrasound Med 2008; 27:1375–1380 1379 279jum1263online.qxp:Layout 1 8/11/08 10:54 AM Page 1380 Postpartum Management of Placenta Previa Accreta Left In Situ References 1. 1380 Kayem G, Davy C, Goffinet F, Thomas C, Clement D, Cabrol D. Conservative versus extirpative management in cases of placenta accreta. Obstet Gynecol 2004; 104: 531–536. 2. Wu S, Kocherginsky M, Hibbard JU. Abnormal placentation: twenty-year analysis. Am J Obstet Gynecol 2005; 192: 1458–1461. 3. 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