Endoscopic laser surgery versus serial amnioreduction for severe twin-to-twin transfusion syndrome

Surgical management of twin reversed arterial perfusion sequence

OBJECTIVE

The purpose of this study was to review our experience in the management of twin reversed arterial perfusion sequence to derive management recommendations.

STUDY DESIGN

All patients with twin reversed arterial perfusion sequence who were seen for consultation between 1993 and 2004 were studied. Criteria for umbilical cord occlusion included abdominal circumference of the twin reversed arterial perfusion fetus that was more than or equal to the pump twin, polyhydramnios (maximum vertical pocket > or = 8 cm), abnormal Doppler studies or hydrops of the pump twin, or monoamniotic twins. Various surgical and access techniques for umbilical cord occlusion were used as they were developed.

RESULTS

Seventy-four patients with twin reversed arterial perfusion sequence were studied. Sixty-five patients were considered surgical candidates, of which 51 patients underwent umbilical cord occlusion attempt. The overall perinatal survival for surgical candidates who had umbilical cord occlusion was 65% (33/51 patients) versus 42.9% (6/14 patients) for the surgical candidates who did not undergo umbilical cord occlusion (P = .1). However, perinatal outcomes in surgical patients were significantly better than expectantly treated surgical candidates if the dividing membrane was not disrupted purposely (22/28 patients; 78.5%; P = .02). Surgery within the sac of the twin reversed arterial perfusion fetus was feasible in 23.5% of patients and was associated with no incidence of premature rupture of membranes, with 83% perinatal survival, and with a significantly greater gestational age at delivery (36 weeks). There were no significant differences in perinatal outcome relative to the specific surgical technique that was used.

CONCLUSION

Surgical management of twin reversed arterial perfusion sequence is indicated in high-risk patients. The surgical approach and the surgical technique should be tailored to the specific clinical presentation, preferably by performing the surgery within the sac of the twin reversed arterial perfusion sequence fetus and avoiding disruption of the dividing membrane.

Fetal medicine: Intrauterine fetal demise following laser treatment in twin-to-twin transfusion syndrome

OBJECTIVE

To evaluate the incidence, risk factors and consequences of intrauterine fetal demise (IUFD) of at least one twin in twin-to-twin transfusion syndrome (TTTS) treated by laser.

DESIGN

Retrospective analysis.

SETTING

Experience of a single centre between 1999 and 2004.

POPULATION

A subgroup of 45 cases with fetal demise of one or both twins from a series of 120 cases of TTTS treated by laser.

METHODS

All cases were entered prospectively into a dedicated database and the results were analysed retrospectively.

MAIN OUTCOME MEASURES

Fetal demise prognostic factors, survival, fetal anaemia, brain lesions, neonatal death and intact survival.

RESULTS

IUFD of one twin occurred in 40 of 120 cases (19 donors and 21 recipients). IUFD of both twins occurred in another five cases. From these 40 cases, miscarriage occurred in two and pregnancy termination was requested in another two cases because of antenatal brain lesions. Two neonates died and two presented severe morbidity, survivors were therefore neurologically normal at 6-44 months of life in 89% (32/36) of the cases. Univariate analysis showed that preoperative abnormal umbilical artery Doppler in the donor before laser treatment and in the recipient following laser treatment was associated with their demise. Incomplete coagulation was suspected in cases where anaemia or cerebral lesions developed following the death of the first twin (10).

CONCLUSIONS

IUFD of one or both twins occurred in 45 of 120 (38%) cases of severe TTTS treated by laser. In these, separation of the placental circulations was incomplete in at least 22% (10/45) of the cases. Umbilical artery Doppler abnormalities before laser were found to be risk factors for the donors' demise following the procedure.

Intertwin anastomoses in monochorionic placentas after fetoscopic laser coagulation for twin-to-twin transfusion syndrome: is there more than meets the eye?

OBJECTIVE

This study was undertaken to detect missed anastomoses on the chorionic surface as well as hidden connections in the depth of the cotyledons in placentas after laser coagulation for twin-to-twin transfusion syndrome (TTTS) and to correlate these findings to clinical outcome.

STUDY DESIGN

All cord vessels were injected with dyed barium sulphate. A digital photograph of the chorionic surface angioarchitecture and single-shot digital X-ray (Rx) angiograms were made. The presence and diameter of any missed anastomoses on the chorionic surface and of any hidden angiographic connections were determined.

RESULTS

Fifty placentas were analyzed, 7 of double intrauterine fetal death (IUFD) and 43 of double survivors. In 9 of 43 (21%) cases with double survival and in all 7 cases of double IUFD, missed anastomoses were identified that should have been ablated by laser coagulation (P < .001). There appeared to be a correlation between the type and diameter of missed anastomoses on the chorionic surface and the clinical outcome. Placentas with missed large arteriovenous/venoarterial anastomoses (AV/VA) (N = 8) were from cases with recurrent TTTS or double IUFD (unless compensated by a large arterioarterial anastomosis [AA]). Next, missed small AV/VA (N = 4) without AA resulted in isolated (ie, without TTTS) discordant hemoglobin levels requiring intrauterine transfusion. Finally, when there were no missed anastomoses (N = 34), TTTS had resolved in all cases and outcome was good, although 1 case had discordant hemoglobin values treated with a single intrauterine transfusion and 4 others had discordant hemoglobin at birth. On Rx angiography, potential hidden connections were present, all but 1 case.

CONCLUSION

Coagulation of all anastomoses visible on the chorionic surface seems adequate to treat TTTS. However, hidden connections in the depth of the cotyledon could not be excluded and may be involved in lesser degrees of intertwin transfusion.

Pregnancy and infant outcome of 80 consecutive cord coagulations in complicated monochorionic multiple pregnancies

OBJECTIVE

This study was undertaken to document pregnancy and infant outcome after cord coagulation with laser and/or bipolar as a technique for selective feticide in complicated monochorionic multiple pregnancies.

STUDY DESIGN

Prospective follow-up study in 2 tertiary fetal medicine centers.

RESULTS

Eighty cases were included in the study (73 twins, 7 triplets). The survival rate was 83% (72/87). There were 9 intrauterine fetal deaths (10%), 5 within 24 hours and 4 between 4 and 10 weeks after the procedure. There was 1 termination of pregnancy because of chorioamnionitis. Median gestational age at delivery was 35.4 weeks, with 79% of patients delivering after 32 weeks. Preterm prelabor rupture of the membranes before 25 weeks accounted for all perinatal deaths (n = 5). Of the children older than 1 year of age (n = 67), 62 (92%) have a normal development.

CONCLUSION

Cord coagulation is an effective method for selective feticide in monochorionic multiple pregnancies.

Prevalence and management of late fetal complications following successful selective laser coagulation of chorionic plate anastomoses in twin-to-twin transfusion syndrome

OBJECTIVE

This study was undertaken to report on the prevalence and management of late complications in twin-to-twin transfusion syndrome (TTTS) treated by laser therapy when both twins are alive 1 week after surgery.

STUDY DESIGN

A total of 151 consecutive TTTS cases were treated by selective fetoscopic laser therapy. Cases in which both twins were alive 1 week after surgery were followed up with ultrasound and Doppler examination, including middle-cerebral artery peak systolic velocity measurement (MCA-PSV).

RESULTS

In the 151 cases treated with laser, both twins were still alive 7 days after the procedure in 101 cases. Intrauterine death of 1 and both twins occurred in 7 and 1 cases, respectively. Recurrence of TTTS with the polyhydramnios-oligohydramnios sequence occurred in 14 (14%) cases. In another 13 (13%) cases, amniotic fluid remained normal in both sacs, but MCA-PSV increased above 1.5 MoM in 1 twin and decreased concomitantly below 0.8 MoM in the co-twin. This was related to anemia and polycythemia, respectively, and resulted from unidirectional feto-fetal blood transfusion, mainly from former recipients into former donors. Late complications were managed accordingly by repeat laser, amnioreduction, cord coagulation, intrauterine blood transfusion, or elective delivery.

CONCLUSION

MCA-PSV Doppler measurements are useful in the follow-up of double survivors to detect and manage late complications after selective laser therapy.

Long-term neurodevelopmental outcome of 167 children after intrauterine laser treatment for severe twin-twin transfusion syndrome

OBJECTIVE

This study was undertaken to investigate long-term neurodevelopmental outcome of children born after intrauterine laser coagulation for severe twin-twin transfusion syndrome.

STUDY DESIGN

One hundred sixty-seven surviving infants treated between June 1997 and September 1999 were investigated at a median age of 3 years and 2 months. All children underwent a detailed standardized physical and neurologic examination and a standardized developmental test (Griffiths' Developmental Test Scales and Snijders-Oomen Non-Verbal-Intelligence Test).

RESULTS

One hundred forty-five infants (86.8%) showed normal development, 12 infants (7.2%) showed minor neurologic abnormalities, and 10 infants (6.0%) major neurologic abnormalities. There was no difference in outcome for the former donors/recipients (P = .349) and between infants who were born as twins or singletons (P = .088).

CONCLUSION

With a high rate (86.8%) of normal neurodevelopmental outcome and an incidence of only 6.0% of major neurologic deficiencies, intrauterine laser coagulation seems to be the best treatment option for severe twin-twin transfusion syndrome.

Perinatal outcome in monochorionic twin pregnancies complicated by amniotic fluid discordance without severe twin-twin transfusion syndrome

OBJECTIVES

To assess the natural history and perinatal outcome in monochorionic diamniotic twin pregnancies with discordant amniotic fluid volume without signs of severe twin-twin transfusion syndrome (TTTS).

METHODS

This was an observational study of 84 consecutive monochorionic twin pregnancies which did not meet the criteria for severe TTTS and endoscopic laser coagulation of placental anastomoses at initial presentation. The population was subdivided into two groups. Group 1 consisted of 64 pregnancies (median gestational age, 20.1 (range, 15.6-24.7) weeks) with amniotic fluid discordance and no signs of congestive heart failure in the twin with the larger amniotic fluid volume (Twin 1) and positive end-diastolic flow in the umbilical artery of the twin with the smaller amniotic fluid volume (Twin 2). Group 2 (median gestational age, 19.1 (range, 16.0-24.4) weeks) consisted of 20 pregnancies with amniotic fluid discordance and intrauterine growth restriction (IUGR) (abdominal circumference < 5th percentile) in combination with absent or reversed end-diastolic (ARED) flow in the umbilical artery of Twin 2. After exclusion of one patient from Group 1, who opted for termination of pregnancy, nine patients in Group 1 and one in Group 2 developed severe TTTS, and laser coagulation was offered. The remaining 54 pregnancies of Group 1 were compared with the remaining 19 pregnancies of Group 2.

RESULTS

Fetuses in Group 1 showed significantly higher survival rates (overall survival, 100/108 (92.6%) vs. 23/38 (60%), P < 0.0001; survival of both fetuses, 49/54 (90.7%) vs. 9/19 (47.4%), P = 0.0002) and median gestational age at delivery (33.6, (range, 27.6-37.8) weeks vs. 32.0 (range, 26.9-36.3) weeks, P = 0.0457). Overall, there was a significantly higher incidence of complications, defined as necessity for intrauterine intervention, fetal or neonatal death or delivery prior to 32 weeks, in Group 2 (Group 1: 30/63 (47.6%); Group 2: 16/20 (80%), P = 0.0188).

CONCLUSIONS

Our data suggest that amniotic fluid discordance in monochorionic diamniotic twin pregnancies in combination with IUGR and umbilical artery ARED flow in one fetus represents an extremely high-risk constellation for adverse pregnancy outcome.

Intrauterine hemodynamic change in TTTS: the alterations in the inferior vena cava waveform in the donor fetus

BACKGROUND

Significant hemodynamic changes are commonly observed in both fetuses in twin-twin transfusion syndrome.

METHODS AND RESULTS

We describe two donor fetus cases in twin-twin transfusion syndrome associated with abnormal waveform patterns in the inferior vena cava after therapeutic amnioreduction. Subsequent echocardiographic examinations demonstrated progressive deterioration of the cardiac function in the recipient fetuses.

CONCLUSIONS

We suggest that alterations in the inferior vena cava waveform in the donor fetuses may contribute to the accurate prediction of deterioration in fetal circulation after amnioreduction.

Manifestation of Mirror Syndrome after Fetoscopic Laser Photocoagulation in Severe Twin-Twin Transfusion Syndrome

Mirror syndrome is a preeclampsia-like disease first described in a case of severe hydrops fetalis caused by rhesus isoimmunization, later reported in some cases of nonimmunological fetal hydrops. Twin-twin transfusion syndrome (TTTS) is a severe complication associated with monochorionic pregnancies, in particular, severe TTTS with one hydropic fetus leading to a poor prognosis. We report here a case of mirror syndrome that occurred after selective fetoscopic laser photocoagulation in severe TTTS at 24 weeks' gestation.

Simulation of therapy in a model of a nonhydropic and hydropic recipient in twin-twin transfusion syndrome

OBJECTIVE

This study was undertaken to model the sequence of events that occurs after amnioreduction, laser therapy, and digoxin administration in twin-twin transfusion syndrome (TTTS) with and without a hydropic recipient twin.

STUDY DESIGN

We added amnioreduction, laser therapy, and digoxin administration to our mathematical TTTS model and simulated combinations of these therapies.

RESULTS

With a nonhydropic recipient, simulated amnioreduction delays the onset of hydrops. Conversely, with a hydropic recipient, amnioreduction aggravates the degree of hydrops. Furthermore, amnioreduction increases the transplacental fluid flow and may temporarily cause a hydropic donor. Laser therapy terminates the cause of recipient hydrops. Digoxin reduces the degree of recipient hydrops, but increases arteriovenous fetofetal transfusion.

CONCLUSION

Laser therapy is superior in TTTS with a hydropic recipient, because simulated amnioreduction aggravates the recipient's cardiovascular status. Digoxin benefits a hydropic recipient but slightly worsens the donor's condition. Therefore, TTTS presenting with a hydropic recipient prior to fetal viability (approximately 26 weeks) may be best treated with laser therapy, whereas more advanced gestations may be offered digoxin administration plus amnioreduction, to delay the progression of TTTS.

Laser for the treatment of twin to twin transfusion syndrome

PURPOSE: To report the initial experience in our country with a new technique for twin to twin transfusion syndrome (TTTS) treatment, using laser to coagulate the placental vessels responsible for the twin transfusion during gestation. METHODS: Prospective study of eight cases diagnosed with TTTS evaluated in our service from january 2001 to june 2005. Through percutaneous introduction of a 2,0mm diameter fetoscope in the uterine cavity, placental surface vessels where directly visualized. Those identified as responsible for the transfusion were laser coagulated. The procedure combines ultrasonography and fetoscopy, in a so-called sonoendoscopic technique (FETENDO). RESULTS: Among the eight pregnancies evaluated, five cases were submitted to the procedure (10 fetuses). All fetuses survived for at least five weeks after surgery. A total of eight fetuses were born alive and five survived the neonatal period. In a 18 months follow-up after birth, all five are still alive and well and their mean age is now 10,6 months. The total survival rate was 50% and in three pregnancies, at least one fetus survived. CONCLUSIONS: Laser fetoscopy is actually the "gold-standard" treatment of TTTS. Nevertheless is a sophisticated technique that epends of proper training. Our service is the first in our country to offer this therapeutic technique. Our success rate is comparable with the international literature.

Current concepts in fetal cardiovascular disease

This article discusses the unique properties of the fetal cardiovascular system and patterns of blood flow in congenital heart disease. It also explores the complex interactive dependency between the developing heart and pulmonary vasculature, with particular attention to hypoplastic left heart syndrome. The article goes on to highlight some recent advances in the understanding of fetal cardiovascular medicine, specifically the possibilities and prognosis for fetal cardiac interventions. An understanding of the enigmatic process of twin-twin transfusion syndrome may help in elucidating one of the mechanisms for development of cardiac structural abnormalities in the fetus.

Neonatal outcome in twin-to-twin transfusion syndrome treated with fetoscopic laser occlusion of vascular anastomoses

OBJECTIVE

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.

STUDY DESIGN

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.

RESULTS

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).

CONCLUSIONS

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.

Selective termination procedures in monochorionic pregnancies

Monochorionic twins have placental anastomoses that to varying degrees create a common circulation. This presents unique challenges for the performance of selective fetal termination in cases of twin-twin transfusion syndrome, twin reversed arterial perfusion sequence, or discordant twin abnormalities. Multiple methods of interrupting the affected twin's circulation have been attempted with variable success. One of the most frequent complications of any approach is iatrogenic preterm premature rupture of membranes. Laser coagulation in the midtrimester appears to be safe and effective; however, it is only available at limited centers. Currently, bipolar coagulation is the method of choice in the second half of pregnancy. The recently reported technique of radiofrequency ablation appears to be successful with minimal complications. Exploration of further percutaneous and noninvasive techniques, as well as interventions to decrease the morbidity arising from preterm membrane rupture, may lead to increased survival of the remaining twin and reduced risk of maternal complications.

Perinatal outcome of spontaneously conceived triplet pregnancies in relation to chorionicity

OBJECTIVE

The purpose of this study was to determine the perinatal outcome of spontaneously conceived triplet pregnancies in relation to chorionicity.

STUDY DESIGN

In this retrospective study, maternal, neonatal, and chorionicity data were collected from 88 sets of triplet pregnancies that were delivered at >20 weeks of gestation from 3 tertiary referral centers in the United Kingdom. The data were collected between January 1986 and December 2000. There were 49 sets of trichorionic triamniotic triplet pregnancies and 39 sets of triplet pregnancies with a monochorionic pair (ie, dichorionic triamniotic triplets). The outcome of each pregnancy was assessed in relation to chorionicity.

RESULTS

The overall perinatal mortality rate was 151.5 per 1000 total births, with dichorionic triamniotic triplets having a 5.5-fold higher risk than trichorionic triamniotic gestations (odds ratio, 5.5; 95% CI, 2.5-12.2). The dichorionic triamniotic triplets have a higher risk of delivery at < 30 weeks of gestation (odds ratio, 4.6; 95% CI, 1.6-11.8; P < .05) and birth weight of < 1000 g (odds ratio, 53.6; 95% CI, 17.5-164; P < .05) than those of trichorionic triamniotic pregnancies. The neonatal morbidity in terms of respiratory distress syndrome (P < .001), anemia (P < .01), and intraventricular hemorrhage (P < .001) were higher in dichorionic triamniotic compared with trichorionic triamniotic triplets. The premature rupture of membrane (odds ratio, 7.5; 95% CI, 3.5-15.7) and twin-twin transfusion syndrome (odds ratio, 14.9; 95% CI, 6.6-4) were independent risk factors for perinatal death.

CONCLUSION

In spontaneously conceived triplets, the incidence of dichorionicity was 44%. The dichorionic triamniotic triplets have a 5.5-fold higher risk of adverse perinatal outcome predominantly because of twin-twin transfusion syndrome and premature rupture of membranes.

Twin-twin transfusion syndrome: where do we go from here?

Management of Twin-Twin Transfusion Syndrome (TTTS) is one of the most challenging clinical problems concerning multiple gestations. The pathophysiology of TTTS and Quintero staging system are described. The importance of fetal echocardiograms in assessing prognosis and response to therapy is highlighted. Treatment modalities, particularly amnioreduction, microseptostomy, and fetoscopic laser photocoagulation, are discussed. Questions still remain as to how various treatment options affect short- and long-term cardiac and neurodevelopmental outcomes and which patients will benefit most from selective laser photocoagulation therapy.

A randomized trial of amnioreduction versus septostomy in the treatment of twin-twin transfusion syndrome

OBJECTIVE

Left untreated, severe twin-to-twin transfusion syndrome (TTTS) presenting in the early second trimester of pregnancy is often associated with significant maternal morbidity and almost universal perinatal loss. Removal of excessive amounts of amniotic fluid through serial amniocenteses (amnioreduction) has been the mainstay of therapy. We sought to compare amnioreduction to intentional perforation of the intervening twin membrane (septostomy).

STUDY DESIGN

Pregnant women with TTTS before 24 weeks' gestation were randomly assigned to serial amnioreduction or septostomy. A single puncture technique under ultrasound guidance was used for the septostomy. The primary outcome measure was survival to neonatal discharge, and was assessed based on the number of pregnancies or the number of fetuses as appropriate.

RESULTS

The study was terminated at the planned interim analysis stage after 73 women were enrolled. This was because the rate of survival of at least 1 infant was similar in the amnioreduction group compared to the septostomy group (78% vs 80% of pregnancies, respectively; RR=0.94, 95%CI 0.55-1.61; P=.82). Patient undergoing septostomy were more likely to require a single procedure for treatment (64% vs 46%; P=.04).

CONCLUSION

Although overall perinatal survival is not enhanced, septostomy offers the advantage of often requiring a single procedure compared to serial amnioreduction in the treatment of severe twin-to-twin transfusion syndrome.

The impact of laser therapy on fetal growth discordance in twin-to-twin transfusion syndrome

OBJECTIVES: to evaluate the impact of laser therapy on inter-twin discordance in twin-to-twin transfusion syndrome (TTTS). METHODS: biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL) and estimated fetal weight were prospectively collected during a five-year period (1999 to 2004). The inter-twin discordance was expressed as a percentage of the largest twin's measurements. The measurements were made the day before laser, twice following laser and after delivery. The mean values of discordance in measurements and in fetal weight were calculated. ANOVA was used to compare mean values. RESULTS: the mean (SD) discordance for BPD, HC, AC, FL and estimated fetal weight the day before laser were 8.53% (5.28), 8.75% (2.76), 16.19% (4.85), 12.92% (5.13) and 28.50% (6.46) respectively. At the at 2nd ultrasound assessment after surgery were 4.37% (3.55), 3.73% (2.71), 8.90% (4.42), 6.61% (4.99) and 19.11% (8.01) respectively; and at birth the weight discordance was 18.55% (8.74). There was a significant decrease in discordance for HC and AC for each ultrasound assessment. CONCLUSIONS: there was a decrease in fetal growth discordance following laser therapy in TTTS. These changes might be related to re-adaptation of blood flow following laser therapy.

Analysis of fetal growth after laser therapy in twin-to-twin transfusion syndrome

OBJECTIVE

The purpose of this study was to evaluate fetal growth patterns after laser therapy in twin-to-twin transfusion syndrome (TTTS).

METHODS

All cases with delivery after 24 weeks from pregnancies complicated by TTTS treated by laser therapy between January 1999 and September 2004 were included. Fetal biometric parameters and estimated fetal weight were measured by sonography at least twice before laser therapy and twice after laser therapy. The interval between sonographic measurements was at least 2 weeks. The study population was divided into group I, which consisted of pregnancies with 2 liveborn neonates, and group II, which consisted of pregnancies resulting in only 1 liveborn neonate. The z scores for biometric measurements were calculated in all cases accordingly and compared for each twin across gestational age by analysis of variance and between groups by a t test. In group I, the intertwin discordance was also assessed, and analysis of variance was used to compare mean values across gestational age.

RESULTS

Ninety-eight cases with 51 single and 47 double liveborn neonates were included. Across time, z scores of the recipients significantly decreased, whereas there was no change in z scores of the donors. The z scores were not statistically different between groups. There was a significant decrease in fetal discordance after laser therapy in group I.

CONCLUSIONS

The fetal growth pattern in TTTS can change after laser treatment. There is a slowdown in the recipient growth and maintained growth in the donor twin. Both mechanisms lead to a decrease in intertwin discordance.

Incidence and impact of perioperative complications in 175 fetoscopy-guided laser coagulations of chorionic plate anastomoses in fetofetal transfusion syndrome before 26 weeks of gestation

OBJECTIVE

The purpose of this study was to evaluate the perioperative complications in fetoscopy-guided laser therapy in fetofetal transfusion syndrome.

STUDY DESIGN

Details of fetofetal transfusion syndrome cases who were delivered between 1999 and 2004 in a single center were reviewed retrospectively.

RESULTS

One hundred seventy-five procedures were performed percutaneously with the use of local anesthesia. Survival at 6 months of at least 1, 1, and 2 babies was 73%, 38%, and 35%, respectively. Placental abruption and miscarriage was diagnosed in 3 and 12 cases, respectively. Premature rupture of membranes occurred in 49 cases (28%) and including 12, 29, and 46 cases that occurred before 24, 28, and 34 weeks of gestation, respectively. The entry of the trocar was transplacental in 48 cases (27%), but it was not associated with miscarriage (P = .26), premature rupture of membranes (P = .58), or placental abruption (P = .37).

CONCLUSION

Fetoscopic laser treatment of fetofetal transfusion syndrome can be performed percutaneously with local anesthesia without significant maternal morbidity. Transplacental entry was not associated with premature rupture of membranes or miscarriage.

Remifentanil for Fetal Immobilization and Maternal Sedation During Fetoscopic Surgery: A Randomized, Double-Blind Comparison with Diazepam

Obstetric endoscopy procedures are routinely performed at our institution to treat selected complications of monochorionic twin gestation. We perform these procedures under combined spinal epidural anesthesia plus maternal sedation. In the absence of general anesthesia, fetal immobilization is not achieved. We hypothesized that remifentanil would induce adequate maternal sedation and provide fetal immobilization, which is equal or superior to that induced by diazepam. Fifty-four second trimester pregnant women were included in this randomized, double-blind trial. After combined spinal epidural anesthesia, maternal sedation was initiated using either incremental doses of diazepam or a continuous infusion of remifentanil. Maternal sedation, hemodynamics, side effects, and fetal hemodynamics and immobilization were evaluated before, during, and for 60 min after surgery. Remifentanil produced adequate maternal sedation with mild but clinically irrelevant respiratory depression (respiratory rate 13 +/- 4 breaths/min and Pco(2) 38.6 +/- 4 mm Hg at 40 min of surgery), whereas diazepam resulted in a more pronounced maternal sedation but no respiratory depression (respiratory rate 18 +/- 3 breaths/min and Pco(2) 32.7 +/- 3 mm Hg at 40 min of surgery). Compared with diazepam, fetal immobilization with remifentanil occurred faster and was more pronounced, resulting in improved surgical conditions; the number of gross body and limb movements was 12 +/- 4 (diazepam) versus 2 +/- 1 (remifentanil) at 40 min of surgery. Because of this, the mean (range) duration of surgery was significantly shorter in the remifentanil-treated patients, 60 (54-71) min versus 80 (60-90) min in the diazepam group. We conclude that remifentanil produces improved fetal immobilization with good maternal sedation and only minimal effects on maternal respiration.

What--and why--the pediatric surgeon should know about twin-to-twin transfusion syndrome

Abstract Endoscopic laser ablation of placental vessels is the most commonly performed fetal operation today. Herein, we review the pathophysiology of twin-to-twin transfusion syndrome and the challenges of its treatment. Pediatric surgeons, with their knowledge of fetal and congenital pathology, and their technical expertise with minimally invasive surgery, can be of great benefit to the patient and the medical team.

Monochorionic twin pregnancies

The monochorionic placenta should be considered a developmental malformation and, as such, represents one of the most common birth defects. Great strides are being made to unravel the progression of nature's successful attempt at human cloning through fission. Critical to any strategy to reduce the perinatal morbidity and mortality associated with monochorionic placentas is early detection. Intense surveillance in at risk pregnancies will provide a better understanding of their natural progression, improve the prognosis with early intervention, and ultimately provide the key to prevent many of the complications unique to the monochorionic placenta.

Antepartum management of multifetal pregnancies

Correct antepartum management of multifetal gestations is a critical skill for practitioners of obstetrics. This article reviews important issues surrounding these complicated pregnancies while discussing current management options and recommendations. Topics include antepartum surveillance, preterm labor prediction, diagnosis, and management, and special situations unique to multiple gestations, such as twin-twin transfusion syndrome and death of one twin in utero. It is the authors' hope that this article is comprehensive in enhancing the reader's knowledge of these complex pregnancies.

Contemporary Treatments for Twin–Twin Transfusion Syndrome

OBJECTIVE

To undertake a systematic review to determine the effects of fetal therapy interventions compared with amniodrainage for twin-twin transfusion syndrome on perinatal survival and outcome.

METHODS

Searching MEDLINE (1966-2004), EMBASE (1988-2004), a hand search of specialist journals, and the Cochrane library (2004:2) identified relevant articles. Studies were selected if the effects of fetal therapeutic interventions for twin-twin transfusion syndrome (laser photocoagulation, serial amnioreduction, septostomy, and selective feticide) on perinatal survival, complications, and morbidity were compared. Study selection, quality assessment, and data abstraction were performed independently and in duplicate.

RESULTS

Only 3 controlled observational studies (comparing treatment in 306 twins) and 1 randomized controlled trial (of 142 twins) were identified. Laser photocoagulation significantly improved perinatal survival of at least 1 fetus and reduced neurologic morbidity compared with serial amnioreduction. No such differences were observed in the comparison of serial amnioreduction with septostomy.

CONCLUSION

In a systematic review of observational and randomized controlled studies, laser photocoagulation of chorionic plate vessels at the intertwin membrane seems to be more effective than serial amnioreduction in the treatment of twin-twin transfusion syndrome with less associated perinatal morbidity and mortality. However, septostomy and selective feticide have not been robustly evaluated.

Philadelphia-chromosome-positive T-lymphoblastic leukemia: acute leukemia or chronic myelogenous leukemia blastic crisis

The Ph1 chromosome has rarely been reported in T-lineage acute lymphoblastic leukemia (T-ALL), and the clinical relevance of this translocation in T-ALL is currently unknown. In chronic myelogenous leukemia (CML) some data indicate derivation of T-cells from the leukemic clone and only a few cases of T-derived blastic crisis have been reported and quite often disputed. Particularly in cases identified initially in blastic crisis it may be difficult to distinguish those from Ph1-positive T-ALL. We herein report 2 patients who presented with a clinical picture of Ph1-positive T-ALL and who raised a differential diagnosis from T-cell blastic crisis of CML. We review the literature and suggest clinical and laboratory features that can help in the diagnosis. According to our literature review, 23 cases of Ph1-positive T-ALL and 44 cases of T-cell blastic crisis of CML, including ours, were reported. Some major differences between the two entities could help in establishing a diagnosis of Ph1-positive T-cell blastic crisis of CML vs. Ph1-positive T-ALL: Male sex and younger age was more predominant in T-ALL. While in most cases of CML blastic crisis there was a history of CML there was no such history in the T-ALL cases. Medullary involvement with lymphoblastic leukemia was present in all cases of T-ALL but only in about half of the cases of CML blastic crisis. None of the CML-blastic crisis cases tested by RT-PCR showed the minor breakpoint transcript, while 2 cases with T-ALL had the minor breakpoint transcript and 1 had both transcripts. Combined morphologic and FISH analysis can help to distinguish between the two entities and was applied in one of our cases. Although both entities carry a severe prognosis, differentiating between them might have clinical relevance, especially in the imatinib era.

Die Entwicklung der geburtshilflichen Sonographie in der Schweiz

Ultrasound has conquered obstetrics during the last 40 years. Today it is an integral part of antenatal care. Its broad use as a screening method has pushed critics who found open doors at health authorities facing short resources. In Switzerland in early 1996, routine ultrasound as a health technology was temporarily excluded from reimbursement by the health insurances. Under the pressure of the public, the health authorities had to reintroduce reimbursement within a few months. However, reimbursement was linked with several conditions: the ultrasound examination has to be performed by physicians with adequate training and experience; routine ultrasound needs a strict informed consent, and its benefit has to be evidenced. This decision has had a positive impact on quality. After 7 years, Switzerland has a good training program; guidelines for prenatal ultrasound already exist in their second edition, and spot checks of performance showed that quality in Switzerland meets international standards. Ultrasound mainly has a positive cost-effectiveness ratio due to the detection of fetal malformations with consecutive termination of pregnancy. Since termination of pregnancy is ethically questionable, the discussion with respect to reimbursement will most probably go on. In this light, a comprehensive informed consent of the pregnant women is essential.

Modeling a hydropic recipient twin in twin-twin transfusion syndrome

We developed a mathematical model of twin-twin transfusion syndrome (TTTS) that includes a hydropic recipient twin, adding interstitial and intracellular fluid compartments, fetal congestive cardiac failure, and the dynamics of renin-angiotensin system (RAS) mediators to our previous TTTS model. Ten differential equations for each twin, coupled by the net fetofetal transfusion of blood and blood components, i.e., colloids, osmoles, and RAS mediators, describe the development of fetal arterial and venous blood volumes, blood osmolality and colloid osmotic pressure (COP), interstitial fluid volume and COP, intracellular fluid volume, amniotic fluid volume and osmolality, and RAS mediator concentration. We included varying placental anastomoses, placental sharing, and amnionicity. The 20 differential equations were solved numerically from 0 to 40 wk with a 0.6-s time step. Consistent with clinical experience, model predictions are as follows. Unidirectional arteriovenous anastomoses and arteriovenous anastomoses inadequately compensated by oppositely directed anastomoses cause severe TTTS that includes a hydropic recipient. Adequately compensated arteriovenous anastomoses simulated TTTS without hydrops. The probability that oppositely directed anastomoses prevent onset of a hydropic recipient after TTTS onset, i.e., the largest interval between onset of TTTS and onset of hydrops in the recipient, was best for a venovenous anastomosis, closely followed by an arterioarterial and finally an oppositely directed arteriovenous anastomosis. Hydropic recipients have decreased amniotic fluid volume. Unequal placental sharing and amnionicity modify hydrops onset. In conclusion, our model simulates a sequence of events that results in a hydropic recipient twin in severe TTTS. The model may allow an assessment of the efficacy of current therapeutic interventions for TTTS cases that include a hydropic recipient twin.

Fetal intervention for congenital diaphragmatic hernia: the European experience

Fetuses with CDH presenting with liver herniation and a lung area-to-head circumference ratio of less than 1.0 have a high chance for neonatal death due to pulmonary hypoplasia. Fetal tracheal occlusion (TO) prevents egress of lung liquid, which triggers lung growth. In animal experiments, we were able to develop a minimally invasive technique for Fetoscopic Endoluminal Tracheal Occlusion (FETO) with a detachable balloon. In 2001, we demonstrated feasibility of FETO by percutaneous access in fetuses with severe CDH. In a retrospective multicenter review, we obtained LHR measurements and position of the liver in 134 cases of isolated left-sided CDH between 24 and 28 weeks. Eleven patients (8%) with LHR < 1.4 opted for termination. Overall survival of liveborn babies was 47% (58/123). LHR and position of the liver correlated both to survival. Combination of both variables predicted neonatal outcome better: liver up and LHR < 1.0 predicted a survival of 9%. When LHR < 0.6, there were no survivors irrespective of liver position. We could successfully perform endotracheal placement of the balloon in 20 cases at a median gestational age of 26 weeks. The mean duration of the operation was 22 (range 5-54) minutes. In 11 (55%) of these patients, there was postoperative prelabor (ie, <37 weeks) amniorrhexis. Membranes ruptured before 32 weeks in 35%, with a decreasing trend as experience increased. Ultrasound scans after FETO demonstrated an increase in the echogenicity of the lungs within 48 hours and improvement in the LHR from a median 0.7 (range 0.4-0.9) before FETO to 1.8 (range 1.1-2.9) within 2 weeks after surgery. The median gestation at delivery was 33.2 (range 27-38) weeks, and in 14 (70%) this occurred after 32 weeks. Surgical repair of the diaphragmatic hernia could be done in 13 babies, and in all but 1 the defect was extensive and required the insertion of a patch. Survival to discharge was 50%. These 10 long-term surviving babies are now aged 7 to 26 (median 19) months without known neurologic morbidity. Eight babies died in the neonatal period due to complications of the underlying disease. Two nonsurvivors died from other causes but with appropriately developed lungs. Improved survival coincided with increasing experience, in turn related to reduced incidence of postoperative amniorrhexis, later delivery, and a change in the policy on the timing of removal of the balloon from intrapartum to the prenatal period. Survival in eligible contemporary controls was 1/12 (8%). The presence of liver herniation and a low lung-to-head ratio (LHR <1.0) is a good predictor of poor prognosis at different tertiary centers around the world. Severe CDH may be successfully treated with FETO, which is minimally invasive and may improve postnatal survival.

Intrauterine growth restriction

PURPOSE OF REVIEW

Intrauterine growth restriction remains one of the major problems in obstetrics. Recent published literature on this problem is summarized in this review.

RECENT FINDINGS

Intrauterine growth restriction contributes disproportionately to neonatal mortality and morbidity in both preterm and term babies, and is a predisposing factor to major psychiatric sequelae such as depression, suicide and suicidal attempts. More evidence is accumulating to show that fetal Doppler changes of the ductus venosus and umbilical vein are good surrogate markers for fetal academia. The timing of delivery remains controversial, however. The Growth Restriction Intervention Trial showed that delayed delivery in those up to 30 weeks may be associated with lower rates of cerebral palsy and Griffiths development quotient under 70. In dichorionic twins, selective fetocide of one severe intrauterine growth restriction fetus in midtrimester twin pregnancies complicated by severe preeclampsia may abort the disease process and prolong the pregnancy. For monochorionic twins, the finding of intermittent absent or reversed end diastolic flow in the umbilical artery may be a manifestation of the transmission of the bi-directional waveforms of arterio-arterial anastomosis, but has been shown to be associated with an increased risk of intrauterine death in the growth restricted fetus and brain damage in the larger fetus.

SUMMARY

The timing of delivery of the preterm growth restricted fetus remains controversial. Intrauterine growth restriction with intermittent absent or reversed end diastolic flow in the umbilical artery of monochorionic twins poses difficulties in assessment.

The evidence base for fetal medicine

This chapter looks at the evidence base for the practice of fetal medicine and surgery. There is very little good-quality research and much activity is based on case reports and series. However, the philosophy of evidence-based practice is now accepted and new randomized trials are being published in the literature (e.g. fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia and laser treatment of the twin-to-twin transfusion syndrome). Many well established techniques would not be suitable for randomized trials but, as new techniques related to established practice are introduced (e.g. middle cerebral artery Doppler assessment), well-designed trials are essential to ensure they are safe, clinically useful and at least as good as standard practice. In this unique area of medicine, where ethical and emotional issues interplay with clinical practice, it is important not to introduce exciting techniques without solid evidence that they are beneficial both in the short and the long term.

Invasive Antenatal Interventions in Complicated Multiple Pregnancies

Multiple pregnancies still pose challenging problems for modern medicine. Complications in monochorionic multiple pregnancies have sparked a revival of fetoscopy as a means surgery on the placenta and umbilical cord. As such, fetoscopic laser coagulation is currently the best first-line treatment for severe twin-to-twin transfusion syndrome. Also, fetoscopic or ultrasound-guided cord coagulation seems to be an effective technique for selective feticide in monochorionic twins, albeit with still considerably higher fetal loss rates compared with selective feticide by potassium chloride injection in dichorionic twins.

Persistent elevation of cell-free fetal DNA levels in maternal plasma after selective laser coagulation of chorionic plate anastomoses in severe midgestational twin-twin transfusion syndrome

OBJECTIVE

This study was undertaken to determine whether laser thermocoagulation for twin-twin transfusion syndrome (TTTS) causes increased cell-free fetal DNA levels in maternal plasma, potentially as a result of placental injury.

STUDY DESIGN

We enrolled 34 patients with twin pregnancies complicated by severe TTTS who underwent fetoscopic selective laser ablation of placental vascular anastomoses. Blood samples were drawn before and sequentially after the procedure. Fetal DNA in maternal plasma was quantified by polymerase chain reaction amplification of a Y-chromosome sequence.

RESULTS

Compared with baseline, median elevations of fetal DNA levels were 0.8% at 30 minutes ( P = .32), 15.8% at 60 minutes ( P = .1), 179.5% at 24 hours ( P = .003), and 172.9% at 48 hours ( P = .003). Factors associated with increased fetal DNA levels at 24 hours after procedure included longer operation time, higher number of vessels ablated, and subsequent in utero fetal death ( P = .01, .04, and .04, respectively).

CONCLUSIONS

Persistent elevation of fetal DNA levels in maternal plasma after laser ablation suggests that circulating fetal DNA could derive from placental injury. Plasma fetal DNA analysis may be an additional prognostic marker for fetal outcome after laser therapy.

Evidence-based care of women with a multiple pregnancy

Women with a multiple pregnancy face greater risks for themselves and their infants than women pregnant with one child. Pre-pregnancy care should focus on avoiding multiple pregnancy. Early prenatal care centres on determining chorionicity and screening for fetal anomalies, with later care focusing on the presentation, prediction and management of preterm birth, and intrauterine growth restriction. The optimal timing and mode of birth are the focus of current multicentre, randomised, controlled trials. However, the data from such trials on care for women with a multiple pregnancy are limited. Many areas of care require better-quality information, including when using assisted reproductive techniques, the optimal number of embryos to be transferred, care after the diagnosis of chorionicity, and the benefits of specialised multiple pregnancy clinics. Better-quality information is required to inform clinical practice for women with complications of multiple pregnancy, including monoamniotic twin pregnancy, treatment of twin-to-twin transfusion syndrome, and care following single intrauterine fetal death.

Discordant growth in twins

Discordant growth in twins contributes significantly to rates of perinatal morbidity and mortality. These rates vary according to chorionicity, timing of onset and severity. We have reviewed English language literature in Medline since 1980. It is clear that diagnosis of discordant growth has improved due to the use of serial ultrasound examination. Following the detection of differences in fetal size, diagnosis is facilitated by umbilical artery and fetal Doppler studies. Management options vary according to chorionicity, timing of onset and umbilical-fetal Doppler studies. The mode of delivery in discordant twins remains controversial. We conclude that ultrasound surveillance of twin gestations, combining serial biometry and selective Doppler studies, is effective in the recognition of significant intrauterine growth restriction in co-twins. Differences in etiology and management underscore the importance of establishing chorionicity routinely as soon as twin gestation is diagnosed.

Management of fetofetal transfusion syndrome

Feto-fetal transfusion syndrome contributes heavily to high rates of perinatal mortality and morbidity in monochorionic multiple pregnancies. Its prenatal management has been controversial for at least 25 years. We review the recent literature in order to present the basis for a pragmatic reappraisal of the management of this condition. Laser surgery of the chorionic plate inter-twin anastomoses is the best first-line treatment when the syndrome develops before 26 weeks' gestation. Survival (including quality of survival) and gestational age at delivery are improved when compared to serial amnioreduction. Second-line treatment options include repeat-laser, intra-uterine blood transfusion, serial amnioreduction, selective feticide using bipolar cord coagulation or elective delivery, depending upon gestational age and the severity of the disease and its complications. We have found that fetoscopic placental surgery has proven itself over simplicity of amnioreduction. There is no evidence that treatment should be customized according to the stage of the disease at diagnosis. Early recognition of the syndrome through fortnightly serial ultrasound follow-up of all monochorionic pregnancies should ensure timely referral and make up for geographical constraints. Laser surgery should now be available in fetal medicine units that are managing at least 20 cases per year.

Cervical length as a prognostic factor for preterm delivery in twin-to-twin transfusion syndrome treated by fetoscopic laser coagulation of chorionic plate anastomoses

OBJECTIVE

To evaluate the risk of spontaneous preterm delivery in relation to cervical length in severe cases of twin-to-twin transfusion syndrome (TTTS) diagnosed before 26 weeks of gestation and treated by laser coagulation of the intertwin placental anastomoses.

METHODS

This was an observational study of cases of severe TTTS diagnosed before 26 weeks of gestation and treated by fetoscopic laser coagulation between January 2002 and December 2003 in three centers. Laser was the first-line treatment in all cases. Elective preterm deliveries before 34 weeks' for maternal or fetal indications, including intrauterine death of both fetuses, were excluded. Transvaginal sonographic measurement of cervical length prior to laser treatment and other risk factors of preterm delivery were evaluated by univariate and logistic regression analysis.

RESULTS

Among the 137 women included, the mean cervical length was 32 and 38 mm in women delivering before and at or after 34 weeks, respectively (P < 0.001). For a cervical length of < 30 mm, the risk of delivery before 34 weeks was 74%. Severity of the disease, deepest vertical pool of amniotic fluid and amniotic fluid volume drained after the procedure were not associated with preterm delivery. Logistic regression analysis identified three independent factors to predict preterm delivery: short cervical length (increased risk), parity (increased risk) and intrauterine death of one twin (decreased risk).

CONCLUSION

In TTTS treated by laser, without indications for elective preterm birth, cervical length before treatment is significantly associated with gestational age at delivery, and this is independent of parity, intrauterine death of one fetus and other risk factors.

Insights into the pathophysiology of twin–twin transfusion syndrome

Twin-twin transfusion syndrome (TTTS) is attributed to trans-anastomotic transfusion between twins. Anastomoses are ubiquitous in monochorionic (MC) placentae, yet TTTS develops in only 15%. Although ex vivo and in vivo studies fail to identify a unique anastomotic signature, TTTS placentae are typically associated with an imbalance in unidirectional arteriovenous anastomoses with absent bidirectional anastomoses. Doppler detection of an artery-artery anastomosis reduces the chance of TTTS, whereas, in those that develop the disease, it improves stage-independent survival. Selective laser is often curative, but an increasingly recognized risk of persistent or reverse TTTS may be attributable to atypical arteriovenous anastomoses not identifiable from the chorionic plate. Simple dysvolaemia fails to explain several phenotypic features, including haematological concordancy, recipient hypertension, and reversibly absent end diastolic flow in the donor. The renin-angiotensin system is upregulated in the donor and downregulated in the recipient's kidneys, while paradoxically raised renin levels in the recipient may contribute to raised afterload along with endothelin. Although research is limited in humans by therapy and the lack of a suitable experimental model, further studies of placental and vascular pathophysiology may not only refine current treatment modalities but may also, in addition, suggest further avenues for downstream management such as genetic predisposition testing or pharmacological intervention.