[Bipolar coagulation used in selective feticide of monochorionic twins with one twin anomaly]

OBJECTIVE

To summarize our preliminary experience of selective feticide with bipolar coagulation in complicated monochorionic twins (MCT), and discuss the clinical application of feticide in discordant MCT.

METHODS

Three MCT with one twin anomaly, in which 2 had severe twin-twin transfusion syndrome (TTTS), stage IV, and 1 had acardiac twin, were identified in the second trimester of pregnancy. To terminate the abnormal twin and isolate the co-twin's circulation completely, selective feticide was performed by umbilical cord occlusion with bipolar coagulation under guidance of ultrasound and fetoscopy. After each invasive procedure, serial monitoring was performed, including procedural complications, Doppler of fetal middle cerebral artery and umbilical artery. Pregnancies were followed up every 2 weeks for fetal growth until delivery. After birth the placentas and the terminated fetuses were examined.

RESULT

Cord occlusion was successfully accomplished in all 3 targeted fetuses, at 21, 22 and 24 weeks of gestation respectively. One case with TTTS was complicated with rupture of the membrane in the terminated fetus the 7th day after the procedure, and a healthy baby was born at 32 weeks. The other case with TTTS delivered a boy by cesarean section at 38 weeks. The third case with TRAP is at 35 weeks of gestations and under regular follow-up. Monochorionicity was confirmed by placental examination after delivery, and the effects of bipolar coagulation were observed at the cord of terminated fetuses.

CONCLUSIONS

Umbilical cord occlusion with bipolar coagulation is an effective procedure for selective feticide in MCT with one twin anomaly. The outcome of normal fetus can be favorable.

Ultrasound-guided radiofrequency-driven umbilical cord occlusion: an in-vitro study

OBJECTIVES

To assess the ability and safety of radiofrequency (RF) to induce cord thermal lesions using in-vitro perfused umbilical cords.

METHODS

Nineteen human term umbilical cords were cannulated at both ends and perfused continuously with saline serum in a saline serum bath (37 degrees C). The RF electrode was then inserted into the cord close to the umbilical vein. Different RF power and temperature controls were applied to determine the optimal RF procedure in terms of cord tissue injury and safety in nine experiments. The safety of RF procedures was investigated in ten cords by measuring temperature changes at different sites close to the RF electrode insertion and the impact of RF on cord narrowing was evaluated by continuous monitoring of intraluminal pressure. Subsequent histopathological analysis was carried out in all cases.

RESULTS

The optimal RF procedure reached a temperature of 100 degrees C in 10 min. RF produced a significant increase in intraluminal pressure (from 54.2 +/- 16.4 mmHg at baseline to 118.3 +/- 42.7 mmHg after 10 min, P < 0.05). There was no significant increase in temperature next to the site of insertion during the RF procedure. Histopathological analysis confirmed a > 30% decrease in cord and vein diameter. Cord tissue lesions were characterized by damage in the vessel walls and in the surrounding Wharton's jelly.

CONCLUSION

Our results suggest that RF might be a feasible and safe technique to induce occlusion of umbilical vessels. Further in-vivo experiments are needed to assess its ability to induce a complete occlusion of the umbilical cord.

Selective feticide in complicated monochorionic twin pregnancies using ultrasound-guided bipolar cord coagulation

OBJECTIVE

To review our experience with selective feticide in complicated monochorionic (MC) twin pregnancies, using ultrasound-guided cord coagulation with a bipolar forceps.

DESIGN

Retrospective analysis.

SETTING

All consecutive umbilical cord coagulations performed at our institution in the second trimester of pregnancy between November 1999 and 2003.

POPULATION

Consecutive cases of complicated MC pregnancies with an indication for selective termination.

METHODS

Ultrasound-guided coagulation of the umbilical cord with a 2.5-mm bipolar forceps under local anaesthesia.

MAIN OUTCOME MEASURES

Indications, gestational age at the procedure, perinatal outcome and neonatal follow up.

RESULTS

Forty-six patients with MC twin pregnancies underwent this procedure. Indications included twin reverse arterial perfusion sequence (n= 17), severe malformation in one twin (n= 7) and agonal presentation or cerebral anomalies of one twin in twin-to-twin transfusion syndrome (TTTS) after laser treatment or serial amniodrainage (n= 22). The procedure resulted in six intrauterine fetal demise (IUFD, 13%), with a rate of 41% and 3% when performed at 16-17 weeks or later, respectively (Fisher P= 0.002). Preterm rupture of the membranes (PROM) before 28 weeks and between 28 and 34 weeks occurred in 9% and 14% of the cases, respectively. All neonatal deaths (four) occurred in cases with PROM at 28 weeks or earlier. Paediatric follow up showed that all infants discharged alive but one were neurologically normal at 3-42 months, which corresponds to 70% of the 46 cases.

CONCLUSIONS

This technique is effective when the natural history is likely to severely affect the development of the normal co-twin. The overall intact survival rate was 70% and our results support justification of later surgery. Prematurity remains a significant complication of the procedure.

Selective reduction of multifetal pregnancy using high-intensity focused ultrasound in the rabbit model

OBJECTIVE

High-order multifetal pregnancies carry a significant risk of obstetric complications and poor pregnancy outcome. Selective reduction has traditionally been performed using transabdominal and transvaginal ultrasound-guided intracardiac injection of potassium chloride. We have previously shown that high-intensity focused ultrasound (HIFU) can create a coagulative tissue necrosis in the sheep fetus. The objective of this study was to investigate the feasibility of non-invasive selective fetal reduction using HIFU in a rabbit model.

METHODS

A protocol for HIFU-induced tissue coagulation was developed in the rabbit model. The fetal heart was targeted with ultrasound-guided tissue ablation by a HIFU beam. Five time-mated does between 20-29 days' gestation underwent transabdominal fetal cardiac ablation in a total of 11 fetuses. The HIFU system consisted of a 7-MHz high-power transducer, operated at 2000 W/cm2. The fetal heart rate was observed using real-time ultrasound with Doppler flow velocimetry. All lesions were assessed macroscopically and by histological analysis.

RESULTS

Severe bradycardia leading to asystole was observed in all targeted fetuses with ultrasound examination. Dissection of fetuses demonstrated a necrotic intrathoracic lesion similar in size to the HIFU focus (approximately 1 x 9 mm). None of the surrounding fetuses was found to have bradycardia during the procedure or a macroscopic lesion on dissection.

CONCLUSION

In this pilot study HIFU seems promising to ablate even highly vascularized tissue in the fetus.

Bipolar coagulation of the umbilical cord in complicated monochorionic twin pregnancy

OBJECTIVES

In monochorionic twin pregnancy in which one twin is a nonviable fetus, selective feticide may be considered. We aimed to occlude the umbilical cord with a bipolar forceps for doing so.

STUDY DESIGN

This was a multicenter experience in 10 consecutive patients either with twin-to-twin transfusion syndrome and one fetus affected by a condition not compatible with normal extrauterine life or with acardiac twinning.

RESULTS

There were no intraoperative problems, and the mean procedure time was 17.5 minutes. The flow was stopped in all 10 cases. Two cases were complicated by rupture of the fetal membranes within 2 days, and the pregnancies were terminated. The other 8 pregnancies resulted in the live birth of a healthy baby. The mean interval between procedure and birth was 15.1 weeks (range, 7-20 weeks). In one patient emergency cesarean delivery for abruptio placentae was done at 26 weeks, 7 weeks after the procedure. The other 7 patients were delivered beyond the 36th week of gestation. All 8 children are alive and well, with a mean follow-up of at least 1 year.

CONCLUSION

Bipolar coagulation is a safe, effective, and simple procedure for cord coagulation that is feasible through a single port and can be performed solely under ultrasonographic guidance.

-Interruption of umbilical blood flow in an acardiac twin by endoscopic laser coagulation-

We report on the successful intrauterine surgical treatment of a twin pregnancy with an acardiac fetus. At 18 weeks of gestation the patient presented with polyhydramnios and a hydropic acardius acephalus and the donor twin showed signs of congestive heart failure. Colour Doppler ultrasound allowed localisation of the communicating vessels running on the placental surface towards the umbilicus of the acardiac twin. At 20 weeks we performed endoscopic laser coagulation of the umbilical vessels of the acardiac twin. A sheath (9.8 Charriere) with a 1.9 mm diameter rigid fetoscope (field of vision 60 degrees) was introduced percutaneously under local anesthesia into the amniotic cavity of the "pump" twin. Under sonographic control the fetoscope was directed towards the communicating vessels on the placental surface. A Nd-YAG laser (0.4 mm diameter fiber) was used to coagulate two vessels, artery and vein, until interruption of the reversed arterial perfusion was accomplished. Tricuspid regurgitation of the normal twin disappeared throughout the following two weeks and no further complications occurred throughout pregnancy. At 39 weeks a healthy girl was delivered vaginally. No at the age of 3 months she is developing normally. Minimal invasive endoscopic laser coagulation of the umbilical vessels of the acardiac twin appears to be the optimal currently available treatment for the normal twin, for which otherwise a high mortality ( > 50%) and morbidity must be expected.

Selective feticide in twin transfusion syndrome using ultrasound-guided insertion of thrombogenic coils

Twin transfusion syndrome is a common complication of monozygotic twin pregnancies. Selective feticide is one of the many different aggressive and invasive therapies that has been suggested to improve an otherwise dismal perinatal outcome. The ideal method of selective feticide remains to be delineated for cases of twin transfusion syndrome that occur remote from term. We describe a case involving the use of intracardiac placement of thrombogenic coils to attempt selective termination.