Jan Deprest

The value of fast MR imaging as an adjunct to ultrasound in prenatal diagnosis

Abstract.The aim of this study was to evaluate the role of MR imaging of the fetus to improve sonographic prenatal diagnosis of congenital anomalies. In 40 fetuses (not consecutive cases) with an abnormality diagnosed with ultrasound, additional MR imaging was performed. The basic sequence was a T2-weighted single-shot half Fourier (HASTE) technique. Head, neck, spinal, thoracic, urogenital, and abdominal fetal pathologies were found. This retrospective, observational study compared MR imaging findings with ultrasonographic findings regarding detection, topography, and etiology of the pathology. The MR findings were evaluated as superior, equal to, or inferior compared with US, in consent with the referring gynecologists. The role of these findings in relation to pregnancy management was studied and compared with postnatal follow-up in 30 of 40 babies. Fetal MRI technique was successful in 36 of 39 examinations and provided additional information in 21 of 40 fetuses (one twin pregnancy with two members to evaluate). More precise anatomy and location of fetal pathology (20 of 40 cases) and additional etiologic information (8 of 40 cases) were substantial advantages in cerebrospinal abnormalities [ventriculomegaly, encephalocele, vein of Galen malformation, callosal malformations, meningo(myelo)cele], in retroperitoneal abnormalities (lymphangioma, renal agenesis, multicystic renal dysplasia), and in neck/thoracic pathology [cervical cystic teratoma, congenital hernia diaphragmatica, congenital cystic adenomatoid lung malformation (CCAM)]. This improved parental counseling and pregnancy management in 15 pregnancies. In 3 cases, prenatal MRI findings did not correlate with prenatal ultrasonographic findings or neonatal diagnosis. The MRI provided a more detailed description and insight into fetal anatomy, pathology, and etiology in the vast majority of these selected cases. This improved prenatal parental counseling and postnatal therapeutic planning.

Underwater Nd:YAG Laser Coagulation of Blood Vessels in a Rat Model

Endoscopic coagulation of placental and umbilical cord vessels has been suggested as a treatment for selected cases of twin-twin transfusion syndrome and of acardiac twin. The feasibility, safety and hemostatic effect of neodymium:yttrium-aluminium-garnet (Nd:YAG) laser in an underwater environment were experimentally studied in an in vivo model, mimicking the in utero situation and fetoplacental vessels. In 10 male Wistar rats, immersed in normal saline at 38 degrees C, femoral vessels, carotid artery, abdominal aorta and vena cava were coagulated under endoscopic control. A 100-Watt Nd:YAG laser was used in continuous mode with a 600-micron fiber. Outcome measurements were vascular diameter, total energy (joules) used to obtain visual coagulation and subsequent vascular obliteration. Overall failure rate was 32% and perforation of the vessel occurred in 7.7% of cases.

Fetoscopic Nd:YAG laser coagulation for twin-twin transfusion syndrome in cases of anterior placenta

Laser coagulation of anastomosing placental chorionic plate vessels was suggested as a treatment of severe twin-twin transfusion syndrome in midtrimester. An anteriorly located placenta may hamper access and visualization of the vessels involved. We treated six women with completely anterior placenta at 18 to 22 weeks gestation. Through a 2- to 3-cm minilaparotomy the uterus was accessed after retraction of the viscera. A flexible cannula was inserted through the uterine fundus, and a 35-degree, 0.20-mm minifibroscope and 400-mm fiber were introduced. All vessels crossing the intertwining membrane were coagulated in a continuous mode and a maximum output of 45 W. All fetuses survived the operation. One fetus died in utero 6 weeks postoperatively from cardiac failure, and its receptor twin was born alive. All other pregnancies are either continuing, or the women delivered two healthy babies. Thus far, total fetal survival is 91.6%, compared with results with posterior-sided placentas. Neodymium:yttrium-aluminum-garnet laser coagulation is also possible in case of anterior placenta, but requires a minimal maternal incision and general anesthesia to allow safe cannula placement. A bent scope allows for a larger placental surface to be treated.

P343a: Fetoscopic laser treatment in monochorionic and dichorionic triplets

(MC) has a longer latency compared to singleton or dichorionic (DC) twin pregnancies with AEDF. Methods: All patients with AEDF in the UA were identified by search of the patient databases in 2 fetal medicine centres. After excluding 21 pregnancies due to incomplete data (n = 18), and structural or chromosomal anomalies (n = 3), a total of 53 MC pregnancies were compared with two cohort groups – singleton pregnancies (n = 74) and dichorionic twins (n = 19). Latency was defined as days from diagnosis of AEDF till delivery or intrauterine death. Results: A total of 146 pregnancies with AEDF were analysed, including 25 MC twins with IUGR (17%) and 28 with TTTS (19%). Median latency was 43 days (7–153) in the MC group, 30 days (1–66) in the DC group and 10 days (range 0–68) in the singletons. MC twins had significantly longer latency than the singletons (p = 0.007), but there was no significant difference with the DCDA. After excluding the TTTS group, non-TTTS MC twins had a significantly longer latency than DC twins. The overall median gestational age at onset of AEDF [176 days (range: 108–253)] was significantly earlier in MC twins (median 147 days) than in DC (190 days) or singleton (189.50 days) pregnancies (p < 0.001). Latency was linearly correlated with gestational age at onset of AEDF (R2 = 0.564). Conclusion: The latency of AEDF is longer in MC twins, suggesting a different patho-physiological mechanism then simple downstream resistance.

Psychological impact of endometrial monitoring in tamoxifen-treated postmenopausal breast cancer patients

In view of the higher incidence of endometrial pathology in tamoxifen-treated breast cancer patients, it has been recommended that endometrial surveillance be performed on these women by means of transvaginal sonography. Our study investigated how breast cancer patients experience the endometrial surveillance and which personality factors influence this experience. We also studied compliance with the recommended examination. Fifty-three consecutive asymptomatic postmenopausal breast cancer patients who had taken tamoxifen for at least 6 months were included. Our results show that 23% of the women felt very anxious just before the examination. One woman in five evaluated the procedure as annoying, unpleasant, invasive and awkward, but only 3% found it really unacceptable. Difficulties in coping with mastectomy as well as anxiety negatively affected the experience of the examination. One in six women were doubtful about their ability to comply with such an examination in the future. Women who have difficulties in coming to terms with the mastectomy, anxious women, and women with a low tolerance towards common medical procedures are at especial risk of becoming dropouts. Suggestions are made for developing strategies that might improve these womens compliance.

P06.08: TTTS before the limits of fetoscopic surgery

Results: 1037 were referred from January 1999 to May 2004. 189 patients (18.2%) had non-TTTS. Of these, 78 (41.2%) were iOLIGO, 65 (34.4%) iPOLY, and 46 (24.3%) sAFVd. Complete follow-up data was available in 141/189 (74.5%) patients. Progression to TTTS occurred in 37%, 26%, and 3% of iOLIGO, iPOLY and sAFVd groups, respectively (p < 0.001). iOLIGO patients were more likely to progress to IUGR than iPOLY patients (p < 0.04). Altogether, iOLIGO patients were less likely to remain unchanged (6.5%) than iPOLY (47.8%) or sAFVd (54%) (p < 0.001). Spontaneous normalization of AFV occurred in 6.5%, 2.2% and 54% of iOLIGO, iPOLY and sAFVd patients, respectively (p < 0.001). The average time for the development of TTTS in non-TTTS patients was 6.5 days. Conclusion: Monochorionic twins with AFV discordance may progress to TTTS or IUGR in a significant proportion of cases. Of the non-TTTS groups, iOLIGO patients are more likely to progress to a TTTS-IUGR. Ultrasound examinations weekly for AFV assessment and monthly for fetal growth are indicated in non-TTTS patients.

OC085a: Selective fetocide in monochorionic twins: Oral communication abstracts

differences were found in blood pressure, stiffness, in endothelium dependent and independent vasodilatation between the two groups. Conclusions: IUGR caused by placental insufficiency appears to be associated with impaired vascular growth persisting into young adulthood. The smaller aortic dimensions and higher resting heart rate seen in both males and females of the IUGR group and the lower aortic compliance coefficient seen in male adolescents may influence the future cardiovascular health in these individuals.

P09.02: Accuracy of magnetic resonance imaging for measuring fetal lamb lungs and organs

This study was to develop fetal growth curves and percentile growth charts for a Jamaican population. 499 jamaican women of African descent were enrolled in a prospective study from the maternity clinic of the University Hospital of the West Indies., Kingston, Jamaica. The women had serial scans between 14–37 weeks’ gestation to measure fetal growth. The measurements performed were BPD, HC, AC and FL. A total of 2574 scans were performed (mean 5.2 per woman). The data was used to plot centile growth charts for the Jamaican fetus. Birthweights vary between ethnic groups so must fetal growth. At present fetal growth in Jamaica is assessed using charts based on Caucasian populations. Fetal growth charts derived from this data would more accurately predict the at-risk fetus and hence improve obstetric care.