Indirect pump: unique presentation of a monochorionic–triamniotic triplet gestation complicated by TRAP sequence and successfully managed with radiofrequency ablation of the acardiac fetus

Abstract

Twin reversed arterial perfusion (TRAP) CASE REPORTA 22-year-old woman, gravida 1 para 0, was found to have a triplet pregnancy at an initial 21-week comprehensive ultrasound examination. Fetal demise with hydropic changes in one of the fetuses was initially suspected. A subsequent ultrasound examination by a maternal-fetal medicine specialist confirmed a monochorionic-triamniotic triplet gestation with absence of cardiac activity in one of the triplets. Additionally, reversed flow in the umbilical cord of this fetus was demonstrated on Doppler ultrasound examination. These findings were consistent with a monochorionic-triamniotic gestation complicated by twin reversed arterial perfusion (TRAP) sequence.On evaluation at our center at 22 + 5 weeks' gestation, Doppler examination confirmed reversed flow through the single umbilical artery of the acardiac fetus, Triplet A. Generalized soft-tissue edema was seen and the amniotic fluid volume was normal (Figure 1). Triplet B, the suspected pump fetus (estimated fetal weight, 377 g), showed an increased amniotic fluid volume with a

Optimal Method and Timing of Intrauterine Intervention in Twin Reversed Arterial Perfusion Sequence: Case Study and Meta-Analysis

“…Early attempts were highly invasive and involved hysterotomy and removal of the acardiac twin [2,3,4]. Subsequently, a series of other less invasive intrauterine interventions aiming to arrest the circulation of the acardiac twin were introduced [5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75]. These included insertion of cord coils, ligation with or without transection of the umbilical cord, endoscopic laser coagulation of placental anastomoses between the pump and acardiac twins, endoscopic laser coagulation and endoscopic or ultrasound-guided monopolar or bipolar diathermy of vessels within the cord supplying the acardiac twin and, more recently, ultrasound-guided ablation of intrafetal vessels by injection of alcohol, monopolar diathermy, laser or radiofrequency.…”

Radiofrequency Ablation with an Internally Cooled Electrode for Twin Reversed Arterial Perfusion Sequence

“…An overview of survival rates of TRAP sequence treated with RFA is presented in table 3[8,16,17,18,19,20,21,22,23]. We excluded the reports that included the cases also reported in other references.…”

“…In this study, we used an internally cooled electrode, and the survival rate of the pump twin was 88%. Comparison of the results must be carefully assessed because reports of the use of an expandable needle electrode included monoamniotic twins and triplets [16,17,18,19]. However, the survival rate with the use of an internally cooled electrode would not be inferior to that with the use of an expandable needle electrode.…”

“…The natural history for TRAP sequence progresses to >50% mortality of the pump twin because of high-output heart failure or premature delivery caused by polyhydramnios [1]. Various intrauterine interventions focused on disruption of perfusion into the acardiac twin have been introduced to improve the outcome of the pump twin: cord coagulation [2,3], umbilical cord ligation [4], photocoagulation of the anastomoses [5], interstitial laser therapy [6,7,8] and radiofrequency ablation (RFA) [8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23]. …”

“…Conversely, an internally cooled electrode can maintain a low electrode temperature, avoid the increase in tissue impedance even with high power and achieve an increase in necrosis volume [26]. At present, in most of the reports regarding RFA for TRAP sequence, an expandable needle electrode was used [8,9,10,11,12,13,14,15,16,17,18,19,20,21] but only a few case reports describe an internally cooled electrode [22,23]. Therefore, it remains unknown which electrode is more suitable for the treatment of TRAP sequence.…”