17th World Congress on Ultrasound in Obstetrics and Gynecology Oral communication abstracts 18 ± 3.4%. PPROM (37%) occurred prior to 32 weeks in 2/16 cases. In all but two cases the balloon could be removed electively at 34.2 ± 1 weeks. Mean GA at birth was 35.4 ± 2 weeks; 44% of fetuses survived (7/16), which fell to 30% (3/10) when cases undergoing FETO beyond 30 weeks were considered. Conclusions: In our experience survival after FETO decreases with GA at balloon insertion. Gestational age at birth and PPROM rates are no different from those reported in cases occluded earlier. Based on experimental data and available clinical experience we would restrict late FETO to fetuses with larger lung sizes (O/E LHR > 25%, who are currently not eligible) or to cases presenting late in gestation. OC218 Update on fetal endoscopic tracheal occlusion for severe left-sided isolated diaphragmatic hernia J. Deprest 1 , J. Jani 2 , E. Gratacos 3 , S. Salcedo 3 , K. Allegaert 1 , A. Greenough 2 , K. H. Nicolaides 2 1 University Hospitals Leuven, Belgium, 2 King’s College Hospital, United Kingdom, 3 Hospital Clinic, Barcelona, Spain Objectives: To report on the outcome of a consecutive series of fetoscopic endoluminal tracheal occlusion (FETO) procedures performed at 26–29 weeks on fetuses with left-sided severe congenital diaphragmatic hernia (CDH). Methods: Eligibility for FETO was a single fetus with severe CDH (lung-to-head ratio (LHR) < 1 and intrathoracic liver) without associated problems. FETO was at 26–29 weeks’ gestational age (GA). The primary outcome measure was postnatal survival. Results were compared to controls from the CDH antenatal registry by severity, based on LHR. Results: A total of 70 patients underwent FETO. Median gestational age at delivery was 35 weeks. Nearly 75% of fetuses had in-utero reversal of occlusion (either fetoscopy or puncture). Survival was 50% in prenatally treated cases, and 11% in cases managed in the neonatal period only. Survival was dependent on LHR prior to the procedure. LHR N Expectant management (%) LHR N FETO task force update (%) 0.4–0.59 2 0 (0) 0.4–0.5 10 2 (20.0) 0.6–0.79 6 0 (0) 0.6–0.7 37 19 (51.4) 0.8–0.99 19 3 (15.8) 0.8–0.9 23 14 (60.9) < 1.0 27 3 (11.1) < 1.0 70 35 (50.0) Conclusions: FETO increases survival in severe CDH. Survival is dependent on preoperative LHR and will serve as the basis for two clinical trials (http://www.euroCDH.org). OC219 Pulsed Doppler evaluation of the pulmonary artery for prediction of survival in fetuses with congenital diaphragmatic hernia treated with tracheal occlusion O. Moreno-Alvarez , D. Oros, E. Hern´ andez-Andrade, J. M. Mart´ ınez, B. Puerto, E. Gratac ´ os Hospital Clinic, Barcelona, Spain Objectives: Fetoscopic endoluminal tracheal occlusion (FETO) is associated with variable survival rates in severe forms of congenital diaphragmatic hernia (CDH), in cases with apparent similar lung sizes. We evaluated the capacity of pulsed Doppler in the pulmonary artery (PA) for the prediction of survival in fetuses with CDH treated with FETO. Methods: The study included CDH fetuses treated with FETO at 24–28 weeks of gestation. PA pulsed Doppler measurements in the contralateral lung were collected before FETO. Waveform analysis included pulsatility index (PI) and peak early diastolic reverse flow (PEDRF). The obtained values were compared with reference ranges constructed from 120 normal fetuses at 24 – 28 weeks and converted to Z-scores. CDH fetuses were classified into different degrees of severity according to the obtained/expected lung to head ratio (LHR O/E): Group I, extreme (LHR O/E < 17%); Group II, severe (LHR O/E 17–30%); and Group III, moderate (LHR O/E 31–40%). All cases were followed up until the neonatal period. Results: The overall survival rate was 57% (11/19). Before therapy, survivors had a significantly higher LHR O/E (29.7% (SD 4.9%) vs. 21.2% (SD 6.8%), P = 0.01); and lower Z-scores for PPA-PI (1.2 (SD 1.3) vs. 3.2 (SD 1.6), P = 0.003); and PPA-PEDRF (2.4 (SD 0.81) vs. 3.9 (SD 1.4), P = 0.03). In relation to the degree of pulmonary hypoplasia, no fetuses in Group I survived (0/3) and all had elevated PPA-PI and PPA-PEDRF values (above 2 and 3.5 Z-scores respectively). In Group II, 6/10 fetuses survived. The rate of abnormal PPA-PI and PEDRF was 3/4 among non-survivors and 1/6 among survivors. In Group III, all except one survived (5/6); the non-survivor had both parameters above 2 Z-scores. Conclusions: PA Doppler might help to identify which fetuses are likely to benefit from intrauterine therapy. OC220 Increased lung echodensity after tracheal occlusion is highly correlated with survival in fetuses affected with congenital diaphragmatic hernia O. Moreno-Alvarez , E. Hern ´ andez-Andrade, J. M. Mart´ ınez, B. Puerto, E. Gratac ´ os Hospital Clinic, Barcelona, Spain Objectives: Accurate prediction of the likelihood of survival shortly after fetoscopic endoluminal tracheal occlusion (FETO) for the treatment of severe congenital diaphragmatic hernia (CDH) might help some parents decide whether to continue or terminate a pregnancy. We evaluated differences in relative tissue echodensity of the fetal lung in fetuses with CDH treated with FETO, and their association with outcome. Methods: The tissue density of the contralateral lung in relation to the side of the CDH was evaluated in 19 candidates for FETO at 1 week before FETO, and between 7 and 14 days after surgery. The relative tissue echodensity was defined as the ratio obtained by comparing the mean pixel brightness of the lung (L) with that obtained from the liver (LV) and bone (B). Changes after FETO and differences between survivors and non-survivors were then analyzed. ROC curves and likelihood ratios were calculated to evaluate the ability of both ratios to predict survival. Results: Overall, the survival rate was 57% (11/19). Before FETO, no differences in ratios were observed between survivors and non- survivors. However, after FETO, fetuses which survived showed significantly higher values of LLVR (1.95 (SD 0.32) vs. 1.44 (SD 0.27), P = 0.001) and of LBR (0.61 (SD 0.11) vs. 0.54 (SD 0.09), P = 0.02) than non-survivors. A cut-off of a 25% relative increment in the LLVR and 8% increment in the LBR after FETO could discriminate all survivors and 75% of non-survivors. Conclusions: Changes in fetal lung echodensity after fetoscopic endoluminal tracheal occlusion might be incorporated into composite scores to establish the likelihood of survival shortly after treatment in CDH fetuses treated with FETO. 434 Ultrasound in Obstetrics & Gynecology 2007; 30: 367–455