Fetoscopic Laser Occlusion Research Articles

Effect of placental vascular distribution on residual anastomoses after fetoscopic laser surgery for twin to twin transfusion syndrome

Objective: To investigate the effect of placental vascular distribution on residual anastomoses (RA) after fetoscopic laser occlusion of chorioangiopagous ressels (FLOC) for twin to twin transfusion syndrome (TTTS). Methods: A total of 57 cases of TTTS after laser surgery were retrospectively analyzed from April 2014 to April 2019 in Peking University Third Hospital. The patients were divided into RA group (24 cases) and non-RA group (33 cases) according to whether RA occurred in the placenta after laser surgery. The clinical characteristics, perioperative conditions, pregnancy outcomes and placental structure characteristics of the two groups were compared. Multivariate logistic regression was used to analyze the risk factors of placental vascular distribution for RA. The RA group was further divided into non-remission group and remission group, and the placental characteristics and pregnancy outcome of the two groups were compared. Results: (1)General clinical characteristics: the age, application of assisted reproductive technology, incidence of gestational hypertension, gestational diabetes mellitus, preoperative maximum amniotic fluid depth of the donor and recipient twins, Quintero stage and placental position of TTTS patients in the two groups were compared respectively, and there were no statistically significant differences (all P>0.05).The gestational age of patients received FLOC in the RA group was significantly higher than the non-RA group [(23.0±2.4) vs (21.9±2.7) weeks, P=0.033].(2) Perioperative conditions and pregnancy outcomes: the delivery gestational age of the RA group was significantly lower than that of the non-RA group (median:31.8 vs 34.4 weeks, P=0.002);The newborn birth weight in the RA group was significantly lower than that in the non-RA group [(1 648±597) and (2 013±481) g, P=0.003].The birthweight difference in the RA group was significantly higher than that in the non-RA group (median:0.30 vs 0.11, P=0.005). (3) The placental structure and the risk factors influencing RA happened: the differences in the proportion of four types of placental vascular distribution in the RA group and non-RA group were different significantly (χ²=10.214, P=0.012), with a detail of parallel type 29% (7/24) and 3% (1/33), staggered type 58% (14/24) and 76% (25/33), hybrid 8% (2/24) and 21% (7/33), monoamniotic membrane type 4% (1/24) and 0 respectively. Multivariate logistic regression analysis showed that parallel placental vascular distribution was an independent risk factor for RA after FLOC (OR=24.5, 95%CI 1.7-336.2, P=0.017). (4) Placental characteristics and pregnancy outcomes in the remission and non-remission groups of the RA group: the incidence of three kinds of anastomoses, the total number, total diameter and proportion of RA, and the placental territory discordance ratio were compared between the two groups, and there were no statistical significances (P>0.05);The birth weight difference ratio in the non-remission group was higher than that in the remission group (median:0.41 vs 0.28, P=0.036). Conclusion: The parallel type of placental vascular distribution may be an independent risk factor for RA in TTTS after laser surgery.

A Cohort Analysis of Patients with Stage I Twin-to-Twin Transfusion Syndrome from a Major Referral Hospital in Northern China

Abstract Objective: To describe the outcomes of Stage I twin-to-twin transfusion syndrome among patients treated with expectant management (EM), amnioreduction (AR), or fetoscopic laser occlusion of chorioangiopagous vessels (FLOC). Methods: A cohort of 89 cases was studied. Based on the initial management strategy, patients were classified into three groups: the EM, AR, and FLOC. We assessed perinatal survival to 28 days of age and categorized pregnancy outcomes as good (twin live birth at ≥30.0 weeks), mixed (single fetal demise or delivery between 26.0 and 29.9 weeks), or poor (double fetal demise or delivery at <26.0 weeks). Results: 26 (29.2%) patients underwent EM, 35 (39.3%) underwent AR, and 28 (31.5%) underwent FLOC therapy. Of those managed expectantly, 19.2% experienced spontaneous abortion, 50% progressed in stage, and 30.8% remained stable or regressed. After adjusting for potential confounders including maternal age, nulliparity, placenta location, and recipient maximum vertical pocket, and so on, FLOC therapy and AR were associated with significantly [odds ratio (OR) = 0.09] and borderline significantly (OR = 0.20) reduced risks of poor pregnancy outcomes and of no survivors to 28 days of age after birth (OR = 0.04 and OR = 0.20, respectively) compared with EM. Conclusion: About 70% of those treated with EM progressed in stage or experienced fetal loss. Compared to EM, intervention may decrease the risk of poor pregnancy outcomes and improve the perinatal survival rate.

Analysis of clinical characteristics of discordant structural malformations in one of monochorionic diamnionic twins

Objective: To analyze the clinical characteristics of structural malformations in one of monochorionic diamnionic twins (MCDA). Methods: The clinical data of 77 MCDA patients with structural malformations diagnosed by ultrasound were retrospectively reviewed from January 2012 to May 2017. The distribution of structural malformations, prenatal chromosomal karyotyping and pregnancy outcomes were analyzed. Results: (1)Among the 77 MCDA patients with structural malformations, the single malformation accounted for 79%(61/77), the multiple malformations accounted for 21%(16/77). And there were a total of 94 types of malformations, the top three malformations were neurological malformations (32%, 30/94), cardiovascular malformations (29%, 27/94) and twin reversed arterial perfusion sequence (TRAPS;10%,9/94).(2)Among the 77 patients with structural malformation, 64 cases (83%, 64/77) were examined for fetal chromosomes, of whom 14 cases (22%,14/64) were examined for fetal chromosomes of both twins, with 1 case (1/14) of discordant fetal chromosome. (3)Among the 77 patients, 4 cases (5%, 4/77) with severe fetal malformations terminated pregnancy. Totally 29 cases (38%,29/77) with severe malformations were treated with selective fetal reduction, among whom 7 cases (24%, 7/29) experienced unexplained fetal death within 24 hours after the operation; 2 cases (7%, 2/29) happened inevitable abortion, and 2 cases (7%, 2/29) underwent unexplained fetal death during the late pregnancy. Of the remaining 44 patients (57%,44/77) with expectant treatment, 13 cases (30%,13/44) occurred twin transfusion syndrome (Ⅱ-Ⅳ), and were treated with fetoscopic laser occlusion. Eight patients had 2 survival twins, 4 patients delivered 1 survival twin, and 1 patient had dead twins. Conclusions: The most common malformations in MCDA twins are the nervous malformations, cardiovascular malformations and TRAPS. The chromosome karyotype of MCDA twins with structural malformations are sometimes discordant, and separate samling of the twins is suggested for prenatal diagnosis. Selective fetal reduction could be given to severe structural malformation in MCDA patients safely and effectively. For non-severe structural malformation in MCDA patients with twin transfusion syndrome, fetoscopic laser occlusion is safe and effective.

223: Outcomes after Solomon fetoscopic laser as the primary treatment for twin-twin-transfusion syndrome

Treatment of twin-twin-transfusion syndrome (TTTS) includes fetoscopic laser occlusion (FLOC), cord occlusion and even pregnancy termination. Since the Solomon FLOC technique achieves more complete separation of the twin circulations (Solomon-RCT, Slaghekke et al., 2014), we have adopted this as the primary treatment of TTTS irrespective of disease severity. We aimed to evaluate the outcomes using this treatment approach. Patients with TTTS had detailed anatomy ultrasound, Quintero staging, middle cerebral artery peak systolic velocity and cervical length (CL) measurement. When TTTS criteria were met, Solomon FLOC was offered (including coexisting selective intrauterine growth restriction (sIUGR), complete anterior placenta or cervical shortening). Obstetric comorbidities were managed independently. We ascertained and compared preoperative characteristics in a clinical training program with 2 attending physicians and 2 fellows to procedure-related outcomes in the Solomon-RCT. 144 consecutive TTTS patients managed in 3 years had similar stage distribution to the Solomon-RCT. Twin size discordance >25% and sIUGR was present in 52 (36.1%) and 22 (15.2%), respectively. 7 (4.8%) had a preoperative cervical length (CL) <25mm. All patients elected Solomon FLOC; complete outcome was obtained for 140 pregnancies. Intraoperative intentional septostomy was less frequent in our cohort (7 (5%) vs. 17 (12%); p=0.024) but rupture of membranes (PPROM) within 2 weeks of FLOC was similar (6 (4%) vs 4 (3%); p=0.27). PPROM at birth was seen in 26 (18%) (vs. 57 (42%); p<0.005, Table). Recurrent TTTS (n=2, 1%) and Twin anemia polycythemia sequence (n=3, 2%) requiring repeat FLOC was similar to the Solomon-RCT rate. Median FLOC to delivery interval was 78.5 days (0-141) resulting in a delivery gestational age of 32.2 weeks (range 18+5 – 38+0). Pre-FLOC CL was unrelated to the interval to delivery (Pearson 0.12, p=0,331; median interval 61 vs 82 days for CL<25 and above respectively, p=0.492). Overall twin survival was significantly higher due to a larger proportion of double twin survival at birth (104 74% vs 87 (64%), p<0.05, Table). Solomon FLOC offered in a clinical setting performs at least as well as anticipated from the randomized trial with superior outcomes compared to any other treatment. In the absence of any absolute contraindication Solomon FLOC should be offered to all TTTS patients irrespective of disease severity.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Effect on maternal blood dilution of fetoscopic laser occlusion of chorioangiopagous vessels in treating twin to twin transfusion syndrome

To evaluate the effect on maternal blood dilution of fetoscopic laser occlusion of chorioangiopagous vessels (FLOC) in treating twin to twin transfusion syndrome (TTTS). The clinical data of 71 cases of TTTS who had FLOC in Peking University Third Hospital were reviewed. Fluid intake, blood pressure, heart rate, red blood cell count, hemoglobin and hematocrit in perioperative 24 hours were analyzed. (1) According to the Quintero staging, 9 cases were stage Ⅰ, 24 were stage Ⅱ, 28 were stage Ⅲ and 10 cases were stage Ⅳ. (2) The average operation time of FLOC was (64.0±16.3) minutes. One case had placental abruption after the procedure; one had placental vessel rupture and 6 women refused to take blood counting. These 8 cases were excluded and 63 cases were included in the study. (3) The perioperative bleeding volume was 3 (1, 5) ml, and the volume of fluid intake, urine, amniotic fluid drainage and net fluid intake in the perioperative 24 hours was 2 050 ml(1 530 ml, 3 700 ml), 2 300 ml (1 100 ml, 3 500 ml), 1 900 ml (1 400 ml, 2 700 ml) and -1 760 ml (-100 ml, -3 350 ml), respectively. There was no significant difference between maternal blood pressure or heart rate preoperatively and postoperatively. (4) The maternal red blood cell count [(3.47±0.36)×10(12)/L versus (3.01± 0.37)×10(12)/L, P=0.000], hemoglobin [(107.8±12.1) g/L versus (95.1±11.2) g/L, P=0.000] and hematocrit [0.313(0.238, 0.387) versus 0.276(0.213, 0.800), P=0.000] decreased significantly 24 hours after FLOC. (5) The postoperative hematocrit decreased more in the group which the amniotic fluid drainage volume was 2 000-3 000 ml than that in the group which the amniotic fluid drainage volume was 1 000-1 999 ml. The blood dilution can not be ignored after the FLOC in TTTS patients. The more the amniodrainage volume during the FLOC, the more the maternal blood dilution would be. It might result from amniodrainage during the FLOC, improved maternal-placenta circulation and tocolytics used after FLOC. More attention should be take about maternal cardiac function and complications related with anemia after FLOC.

P19.07: Fetoscopic laser occlusion and transection for twin‐reversed arterial perfusion sequence

<scp>P</scp>19.07: Fetoscopic laser occlusion and transection for twin‐reversed arterial perfusion sequence

Giant Chorioangioma Treated In Utero via Laser of Feeding Vessels with Subsequent Development of Multifocal Infantile Hemangiomas

We report a case of a giant placental chorioangioma (15.6 cm diameter) complicated by polyhydramnios and severe fetal heart failure. Fetoscopic laser occlusion of a dominant feeding vessel was performed at 29 weeks’ gestation and partial devascularization was achieved. In the 33rd week of the pregnancy, the decision was made to preemptively deliver the fetus due to persistent signs of fetal cardiac failure. After birth, the infant developed multifocal infantile hemangiomas with extracutaneous involvement. We posit that the development of infantile hemangiomas may be linked to the presence of the large chorioangioma. Further study is required to ascertain if fetal treatment of the chorioangioma may have been an exacerbating factor.

Twin-to-twin transfusion syndrome--30 years at the front.

Thirty years ago, twin-to-twin transfusion syndrome (TTTS) was one of the most challenging problems of modern obstetrics. The associated mortality and morbidity was staggering, and a sense of hopelessness prevailed among clinicians and pediatric pathologists. Technical advances in ultrasound, endoscopy, video recording, and medical lasers formed the basis for diagnosis and in utero therapy of placental disorders. We review some historical events which gave rise to a new treatment modality for TTTS, fetoscopic laser occlusion of chorioangiopagous vessels, now the most common operation performed worldwide in behalf of fetuses in peril.

Research of placental vascular distribution and clinical outcome in monochorionic twins

To study the placental vascular distribution of monochorionic (MC) twins with twin-to-twin transfusion syndrome (TTTS) or birth weight discordance. Twenty-eight MC placentas were injected in Peking University Third Hospital between Feb. 2010 and Feb. 2011. The vascular distribution type (parallel, crossed, mixed and monoamniotic), the anastomosis of vessels and the placental sharing were recorded. The outcome of pregnancy and the placental characteristics of birth weight discordance (birth weight discordance≥20%) in non-TTTS MC twins were analyzed. (1) The outcome of pregnancy: the miscarriage or gestational weeks of 28 MC twins were 20 to 38 weeks (median of 35 weeks). Six cases were TTTS, 3 of which received fetoscopic laser occlusion of communicating vessels (FLOC). There were 48 live births, with an average birth weight of (2036±623) g. (2) Type of placental vascular distribution:in the 28 MC placentas, number of parallel, crossed, mixed and monoamniotic type of placental vascular distribution were 4 (14%), 14 (50%), 6 (21%) and 4 (14%) cases, respectively. No parallel type was found in TTTS. There was no significant difference of vascular anastomosis or unequal placental sharing among the different placental vascular distribution types (P>0.05). (3) Characteristics of placental vascular distribution in birth weight discordance twins:there were 20 non-TTTS MC twin pregnancies, all of which got live births of both babies. Birth weight discordance equal to or more than 20% was found in 6 pairs of newborns, while birth weight discordance less than 20% was found in the rest 14 cases. Ratio of unequal placental sharing was significantly different between the two groups (P<0.01). There was no significant difference of umbilical cord insertion, placental vascular distribution and anastomosis in the two groups (P>0.01). Vascular distribution type of MC twins might be related to TTTS. Unequal placental sharing is a risk factor of birth weight discordance in non-TTTS MC twins.

396: Predictors of recurrence after fetoscopic laser occlusion (FLOC) for twin-to-twin transfusion syndrome (TTTS)

Incomplete treatment of twin twin transfusion (TTTS) following fetoscopic laser ablation has been reported in 0-19% of procedures. The aim of this study was to identify factors contributing to TTTS recurrence after FLOC (RA-FLOC).

Fetoscopic guided laser occlusion for twin-to-twin transfusion syndrome in 33 cases

To evaluate the clinical effect of fetoscopic laser occlusion of chorioangiopagous vessels (FLOC) for monochorionic diamniotic twins (MCDA) pregnancies complicated with twin-to-twin transfusion syndrome(TTTS). The clinical data of 33 consecutive cases of TTTS from Mainland China, who had FLOC in the Department of Obstetrics and Gynaecology of Prince of Wales Hospital (The Chinese University of Hong Kong) from November 2003 to December 2010, were reviewed and analyzed for peri-operative complications, perinatal outcomes and fetal survival rate. Clinical stage of TTTS was according to the Quintero staging system. (1) Pregnancy characteristics: the mean maternal age was 30; the median gestational age at FLOC was 23(+4) weeks; according to the Quintero staging system, 3 cases were Quintero staging I, 14 cases were Quintero staging II, 7 cases were Quintero staging III and 9 cases were Quintero staging IV. For the 3 stage I cases, FLOC was performed for severe maternal symptoms of polyhyramnios or severe fetal cardiac dysfunction. (2) COMPLICATIONS: intraoperative complications occurred in 5 patients including four uterine bleedings at the puncture site, one placental vascular anastomosis bleeding. Postoperative complications occurred in 6 patients including 2 abortions and 1 intrauterine death within one week after operation, 2 abortions and 1 amniotic band syndrome occurred from two to four weeks after operation. (3) Perinatal outcome and fetal survival rate: the median interval of 33 patients between FLOC and delivery was 9(+4) weeks; the median gestational age at delivery was 31(+6) weeks; the gestation at delivery was less than 24 weeks in 6% (2/33), 24 to 28 weeks in 21% (7/33), 28 to 32 weeks in 18% (6/33), 32 to 37 weeks in 55% (18/33). The mean birth weight of the donor was 1600 g (350 - 2520 g); the mean birth weight of the recipiert was 1930 g (400 - 3040 g). The overall survival rate, the double infant survival rate, the single survival rate and survival rate for at least one twin was 59% (39/66), 52% (17/33), 15% (5/33) and 67% (22/33), respectively. The overall survival rate dropped from 61% (17/28) in Quintero staging II to 9/18 in Quintero staging IV. FLOC for MCDA complicated with TTTS is associated with an overall survival of about 60%. Major complications are rare. The outcome is not only related to Quintero staging but also the close monitoring and timely termination of pregnancy.

368: Cardiovascular profile in recipient and donor twins and relationship with survival following fetoscopic laser occlusion (FLOC)

368: Cardiovascular profile in recipient and donor twins and relationship with survival following fetoscopic laser occlusion (FLOC)

1214 Survival After Fetoscopic Guided Laser Occlusion (FLOC) of Twin-To-Twin Transfusion Syndrome

Background and aim: Untreated twin-to-twin transfusion syndrome (TTTS) carries a mortality rate of approximately 80%. To improve survival, fetoscopic laser occlusion (FLOC) treatment of placental anastomoses has been introduced during the last decade in Sweden. We aimed to determine survival after introduction of this intervention. Methods: Data from all TTTS pregnancies (n=67) treated with FLOC from 2001-09 was assessed. In Sweden, FLOC is carried out at one center i.e. at Karolinska University Hospital, Stockholm. Rates of survival and intra-pair differences were analyzed, as well as maternal risk factors. The severity of TTTS in the cohort was graded according to Quintero (stage I n=2, stage II n=30, stage III n=29, stage IV n=6). Laser treatment was offered at a gestational age of 21 (17-26) weeks and delivery occurred at 29 (19-41) weeks. Results: In 76%, at least one twin was live-born. The rate of fetal survival in donors was 60% and in recipients 66% (p< 0.001). 1 year-survival was 37% in donors and 44% in recipients (p=0.01) and in 57% at least one twin was alive. There was no significant difference in survival when adjusted for Quintero stages, parity, maternal BMI or smoking whereas higher maternal age was associated with higher survival of both twins (p< 0.05). Conclusions: Survival of at least one twin after FLOC was comparable to corresponding data of other international centra. Recipients are more likely to survive than donors. The finding of an increased survival rate with maternal age needs further investigation.

Changes in umbilical venous volume flow after fetoscopic laser occlusion of placental vascular anastomoses in twin-to-twin transfusion syndrome

To examine effects of fetoscopic laser occlusion of placental vascular anastomoses on umbilical venous volume flow in twin-to-twin transfusion syndrome. Absolute umbilical venous volume flow, measured preoperatively and 48 hours after fetoscopic laser occlusion was related to Doppler studies, bladder filling in donors, and anastomoses. Among 45 patients, recipients had decreased ductus venosus pulsatility index (ductus venosus-pulsatility index for veins, 1.16 vs 1.01; P < .001) and unchanged umbilical venous volume flow after fetoscopic laser occlusion (74.7 vs 74.5 mL; P = .407). Donors had decreased umbilical artery pulsatility (1.34 vs 1.11; P = .008), increased ductus venous-pulsatility index for veins (0.75 vs 0.91; P < .014), and significantly increased umbilical venous volume flow per kilogram by 52.3% (136.6 vs 208.0 mL/Kg/min; P < .001). Donor bladder filling occurred at higher umbilical venous volume flow per kilogram (142.7 vs 221.4 mL/Kg/min; P < .012). Increase in umbilical venous volume flow per kilogram correlated with the net difference in arteriovenous anastomoses (Pearson r = 0.403, P = .006). Fetoscopic laser occlusion in twin-to-twin transfusion syndrome corrects intertwin differences in umbilical venous volume flow by predominant effects in the donor. Reappearance of donor bladder filling correlates with correction of volume flow.

Placental Laser Surgery for Severe Previable Feto-fetal Transfusion Syndrome in Triplet Gestation

Information on feto-fetal transfusion syndrome (FFTS) in higher-order multifetal gestation is limited. We report outcomes of 10 triplet pregnancies treated by fetoscopic laser occlusion of the chorioangiopagous vessels (FLOC). The study period was August 1992 to August 2008. Inclusion criteria were gestational age < or =25 weeks and ultrasound confirmation of monochorionicity in at least one twin set and FFTS. Treatment included FLOC, exit amnioreduction, and cerclage when indicated. Hospital records, placental pathology, neonatal course, and long term follow-up of the mother and infants were reviewed. There were eight triamnionic dichorionic and two triamnionic monochorionic triplets. Mean maternal age was 29.8 years, and five conceived following in vitro fertilization. FFTS stage at treatment was > or =II in all cases, at a mean gestational age 20.9 +/- 2.2 weeks. Two patients required immediate rescue cerclage, and all 10 had hypoproteinemia and anemia. Mean age at delivery was 31.2 +/- 3.4 weeks, with a mean birth weight 1568.4 +/- 498 g for the live-born fetuses. Twenty-three (77%) fetuses survived, with at least one fetus surviving in 9 (90%) cases. Cerebral ultrasound imaging and neurological examination were normal in all neonates, and clinical follow-up has remained normal at 67.5 +/- 56 months for the group. FLOC is feasible in dichorionic and monochorionic triplet pregnancy complicated by FFTS. Outcomes are comparable to our experience with twins, namely improved perinatal survival and neonatal morbidity when compared with alternative treatments.

638: Outcome of fetoscopic laser ablation for twin twin transfusion syndrome in relation to procedure details

Fetoscopic laser occlusion (FLOC) can provide definitive treatment for previable twin twin transfusion syndrome (TTTS). It was our aim to determine the relationship between procedure quality and outcome.

OC119: Perioperative prognostic factors in twin–twin transfusion syndrome treated by selective fetoscopic laser occlusion of chorionic plate anastomoses

OC119: Perioperative prognostic factors in twin–twin transfusion syndrome treated by selective fetoscopic laser occlusion of chorionic plate anastomoses

Peri-operative prognostic factors in twin-to-twin transfusion syndrome treated by fetoscopic laser occlusion of chorionic plate anastomoses

To describe peri-operative prognostic factors of survival without impairment in twin-to-twin transfusion syndrome (TTTS) treated by fetoscopic laser occlusion of chorionic plate anastomoses. Monochorionic pregnancies complicated with severe TTTS and treated by fetoscopic laser surgery were reviewed between 1999 and 2005. Peri-operative factors studied included maternal characteristics, severity of the fetal syndrome and characteristics of surgical procedures and were collected prospectively but analysed retrospectively. Primary outcome was survival >28 days of at least one twin without severe impairment. Univariate and multivariate analyses using logistic regression were conducted. 10 of a total of 323 cases were lost to follow-up and excluded from analysis. Median gestational age at diagnosis (25th, 75th percentile) was 21 (19, 23) weeks of gestation. Distribution across Quintero stages was: 17.4%, 40.2%, 37.3% and 5.1% for stages 1, 2, 3 and 4 respectively. Overall survival rate of at least one twin without severe impairment was 65%. Significant factors found in univariate analysis were donor and recipient estimated weight at diagnosis (p=0.02, OR=1.77 [1.07-2.96] and p=0.001, OR=2.12 [1.27-3.59] respectively), discordant growth (p=0.04, OR=1.66 [1.01-2.77]), number (≥4 vessels) and proportion (≥60% of all coagulations) of selective coagulations ((p=0.01, OR=1.81 [1.11-2.99]) and (p=0.02, OR=1.77 [1.08-2.92]) respectively) as well as amniotic fluid volume ≥1 litre drained (p=0.001, OR=2.18 [1.26-3.79]). Multivariate analysis showed that only the recipient's estimated weight at diagnosis and selective coagulations ≥4 during the procedure were significantly predictive of survival (p=0.002, OR=2.20 [1.34-3.63] and p=0.001, OR=1.89 [1.17-3.07] respectively). In severe TTTS treated by fetoscopic laser occlusion of chorionic plate anastomoses, peri-operative prognosis is based upon estimated fetal weight at diagnosis and selectivity of the procedure.

Neonatal Outcome in Twin-To-Twin Transfusion Syndrome Treated with Fetoscopic Laser Occlusion of Vascular Anastomoses

To determine neonatal mortality and morbidity rates in monochorionic twins with chronic twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser occlusion of vascular anastomoses. In a prospective study of monochorionic twins delivered at our center between June 2002 and December 2004, neonatal outcome was assessed in 40 monochorionic twin pairs with TTTS treated with laser compared with 46 monochorionic twin pairs without TTTS. The neonatal mortality rate in the TTTS and no-TTTS group was 8% (6/76) and 3% (3/90), respectively. The rate of severe cerebral lesions on ultrasound scanning in the TTTS and no-TTTS group was 14% (10/72) and 6% (5/82), respectively. The incidence of adverse neonatal outcome (neonatal death, major neonatal morbidity, or severe cerebral lesions) in the TTTS and no-TTTS group was, respectively, 26% (20/76) and 13% (12/90) (RR = 1.97, 95% CI = 1.03 to 3.77). Although perinatal outcome in TTTS has improved after laser therapy, neonatal mortality and morbidity rates remain high. Relative risk for adverse neonatal outcome is increased 2-fold in TTTS treated with laser relative to monochorionic twins without TTTS.

The effect of treatment of twin-twin transfusion syndrome on the diagnosis-to-delivery interval.

No randomised controlled trials of treatment of twin-to-twin transfusion syndrome (TTTS) exist. Since severely preterm neonatal survival has increased over time, survival as an outcome measure is confounded by improvements in neonatal care. The diagnosis-to-delivery interval is a measure of success of treatment independent of improvements in neonatal care. We wished to evaluate whether treatment of TTTS is associated with a lengthening of the diagnosis-to-delivery interval. MEDLINE search was performed supplemented by careful reference review. All TTTS series were included where the following information on each patient was available: survival, fetal demise, gestational age at diagnosis and diagnosis-to-delivery interval in days. gestational age at diagnosis < 29 weeks and diagnosis by ultrasound in the absence of maternal symptoms. Cases undergoing multiple types of treatment were excluded. Eight publications met inclusion criteria and included the following cases: controls (n = 16), amnioreduction (n = 61), septostomy (n = 12), and fetoscopic laser occlusion of chorioangiopagus vessels (n = 51). There was no difference in the diagnosis-to-delivery interval, overall survival, at least one survivor, or number of fetal deaths between the four groups. Logistic regression using at least one survivor as the dependent variable revealed a positive association with gestational age at diagnosis and with diagnosis-to-delivery interval, a negative correlation with fetal death, and no correlation with treatment group. We conclude that there is no difference in diagnosis-to-delivery interval or survival for any treatment for TTTS compared to expectant management. The lack of significance appears to be due to small sample sizes.