Ultrasound-Guided Superficial Temporal Artery Cannulation for Proximal Arterial Pressure Monitoring During Coarctation Repair With an Aberrant Right Subclavian Artery in a Low-Birth-Weight Neonate

Coarctation of the aorta (CoA) complex with an aberrant right subclavian artery (ARSA) poses a significant challenge for intraoperative cerebral perfusion assessment because arterial pressure from both the upper and lower extremities becomes unreliable during aortic arch reconstruction. We report a 14-day-old male neonate weighing 1.819 kg with CoA complex, including patent ductus arteriosus (PDA), right-ventricle-type single ventricle, double-outlet right ventricle, single atrium, total anomalous pulmonary venous return (type IIa), mitral atresia, and ARSA, who underwent left subclavian artery flap aortoplasty, PDA clipping, and pulmonary artery banding. Because both subclavian and descending aortic circulations were expected to be unreliable during aortic cross-clamping, the superficial temporal artery (STA) was selected as the only feasible site for real-time cerebral perfusion monitoring. Preoperative ultrasound revealed an extremely small STA (0.47×0.35 mm), yet ultrasound-guided cannulation using a high-frequency linear probe enabled the successful placement of a 24-gauge catheter and provided stable arterial waveforms throughout the procedure. This allowed continuous assessment of cerebral perfusion during aortic cross-clamping and confirmation of the absence of residual pressure gradients after repair. Postoperatively, the patient required diaphragmatic plication for phrenic nerve palsy but otherwise recovered satisfactorily. This case illustrates that ultrasound-guided STA cannulation can be an effective and feasible monitoring option in low-birth-weight infants with complex cardiac anatomy when conventional arterial sites are not usable.