Anesthetic Management of the First Microwave Ablation for Twin Reversed Arterial Perfusion Sequence in the Philippines

A BSTRACT Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic twin pregnancy associated with high perinatal morbidity and mortality. While microwave ablation (MWA) has been accepted internationally as a feasible intervention, anesthetic considerations remain underreported, particularly in low- and middle-income settings. This report describes the first documented case in the Philippines of the anesthetic management for MWA in TRAP sequence, providing new insights into the perioperative care of pregnant patients with this condition. We report a 37-year-old gravida 2 para 1 at 24 weeks and 5 days of gestation with a monochorionic diamniotic twin pregnancy complicated by TRAP sequence. The patient underwent ultrasound-guided MWA of the acardiac twin under spinal anesthesia with a T4 block. She remained awake with minimal sedation to preserve spontaneous respiration, with strict hemodynamic monitoring, and phenylephrine boluses for transient hypotension. The procedure was uneventful, and Doppler confirmed cessation of umbilical flow to the acardiac twin. Eleven days later, preterm labor required cesarean delivery. The acardiac twin lacked cranial and upper limb structures, whereas the pump twin was intubated and admitted to the neonatal intensive care unit but died on the 12 th day of life from complications of severe prematurity. MWA for TRAP sequence can be safely performed under spinal anesthesia with minimal sedation, ensuring patient cooperation and maintaining spontaneous respiration, while providing vigilant hemodynamic support. Our approach optimized intraoperative ultrasound imaging conditions and maternal–fetal safety. This case supports neuraxial technique as a practical anesthetic strategy for MWA.