Intraoperative transesophageal echocardiography under aortic arch branch blood flow monitoring in a patient with an aberrant left subclavian artery: a case report.

BACKGROUND: Transesophageal echocardiography (TEE) is widely used in cardiac and non-cardiac surgeries with major hemodynamic fluctuations. In patients with vascular anomalies near the esophagus, such as an aberrant left subclavian artery (ALSA), TEE may pose a risk of vascular compression. However, no guidelines exist. CASE PRESENTATION: A 19-year-old woman with biliary atresia underwent living donor liver transplantation. Preoperative imaging showed a right-sided aortic arch with ALSA coursing posterior to the esophagus, and ALSA compression was considered a risk during TEE. Therefore, bilateral radial arterial pressures and regional cerebral oxygen saturation (rSO₂) were monitored. The TEE probe was inserted under videolaryngoscopic guidance without resistance or hemodynamic disturbance, and no arterial waveform attenuation or rSO₂ changes occurred. Transplantation was uneventful, and the patient showed no postoperative neurological or upper-limb deficits. CONCLUSION: This case highlights that appropriate imaging and monitoring strategies can support safe TEE use in non-cardiac surgery, even with vascular anomalies.