A rare subclavian artery aneurysm potentially misidentified as the internal jugular vein in ultrasound-guided central venous catheterization-a case report.

Background: Central venous catheterization by anesthesiologists carries risks such as accidental arterial puncture. This case report highlights a rare subclavian artery aneurysm (SAA) detected during ultrasound-guided internal jugular vein (IJV) access, emphasizing the importance of recognizing anatomical variations.

Case: An 88-year-old female with hypertension and atrial fibrillation was scheduled for lumbar laminectomy and posterior fusion. Preoperative evaluation revealed right lower lobe atelectasis and mild aortic sclerosis. During ultrasonography for right IJV catheterization, two vessels of different diameters were observed on the common carotid artery's (CCA's) lateral side. The larger vessel disappeared at the upper neck level, showing arterial pulsation on Color Doppler. Postoperative neck computed tomography confirmed a right SAA and a 5-mm saccular aneurysm in the left intracranial artery. The patient had no vascular disease, trauma, or relevant family histories.

Conclusions: Anesthesiologists should be aware of anatomical variations during IJV catheterization. Ultrasound with Doppler is crucial for accurate artery identification.