[Interstitial laser coagulation in Twin Reversed Arterial Perfusion sequence].

Twin Reversed Arterial Perfusion (TRAP) sequence complicates about 1% of all monochorionic twin pregnancies and about 1 to 35000 of all pregnancies. It involves an acardiac twin whose structural defects are incompatible with life, and an otherwise normal "pump" co-twin. As the blood flow in the acardiac twin is reversed, it keeps on growing owing to the oxygenated blood from the co-twin. Here we report a case of monochorionic, diamniotic twin pregnancy after ICS/-ET complicated with TRAP sequence, diagnosed at 11 weeks of pregnancy The unusual finding in this case was the residual heart in the so called acardiac twin. Gradually the normal twin developed signs of hemodynamic compromise. Reversed a-wave in ductus venosus was observed. The acardiac twin showed subcutaneous oedema. On 24 November 2011 a successful interstitial ultrasound-guided laser coagulation was performed at 16 weeks of gestation. 17G needle and 0.6 mm laser fibre were used. The needle was introduced into the pelvic region of the acardiac twin through the abdominal wall. A series of laser bursts lasting 5-10 seconds were fired, until cessation of blood flow in the pelvic vessels and umbilical cord of the acardiac twin was confirmed using colour Doppler. The course of the intervention was uneventful. Routine steroid therapy was administered at 27 weeks of gestation. At 32 weeks the patient was hospitalized and oral antibiotics were administered due to premature rupture of the membranes and suspicion of intrauterine growth retardation of the pump twin. The patient delivered spontaneously at completed 33 weeks of pregnancy (weight 1805g, Apgar 10). After the delivery a stage 2 intraventricular hemorrhage and jaundice were observed in the neonate. Phototherapy was administered and the mother and the child were eventually discharged from the hospital, both in good general condition. Since then, two more successful interstitial laser coagulations in TRAP sequence were performed in our institution. The essence of the treatment of TRAP sequence is cessation of the blood flow from the pump to the acardiac twin. Fetoscopic cord ligature or coagulation, and laser or radiofreqency ablations of the acardiac twin vessels, are the possible methods of intervention. The interstitial laser coagulation of the acardiac twin is less invasive than fetoscopic umbilical cord coagulation, as the outer diameter of the 17G needle is much smaller. A meticulous comparison of these methods would require a randomised study but at 16 weeks of MCDA twin pregnancy interstitial laser coagulation seems to be the method of choice. The outcome of the procedure and possible treatment options in case of TRAP together with the review of literature, are presented in the article.