Intraoperative identification of the circumflex artery and verification of flow by Transesophageal Echocardiography (TEE) for mitral valve procedures

Aims: Occlusion of the circumflex artery (CX) is a rare but feared complication in mitral valve surgery. Intraoperative diagnosis is difficult.

Objective: To assess the feasibility of detecting the CX by TEE, verify flow and distinguish the CX from the coronary sinus (CS).

Methods: After ethics approval, we prospectively performed TEE in 50 pts (23 f/27 m) undergoing minimally invasive mitral valve repair. Turning the echo probe from the midesophageal long axis view to the left, we followed the course of the CX from the left main to the distal CX. We measured CX diameter near the main stem and distally, CS diameter (near the right atrium and near the crossing), and assessed flow by color Doppler.

Results: All patients underwent successful repair without clinical evidence of CX occlusion. The course of the CX could be followed to the crossing of the CS in all 50 patients. Distal to the crossing, the CX could be identified in 43 patients. The diameter of the CX decreased from proximal to distal (from 4.1±0.9 to 3.1±0.7mm). In contrast, CS diameter increased in these views (from 4.0±0.8mm to 6.05±1.1mm). Flow could be detected pre- and postoperatively in both vessels by color Doppler in 46 patients.

Conclusion: The CX can be successfully detected by TEE and can be discriminated from the CS by observing the opposing diameter changes of both vessels. Since Doppler flow can reliably be imaged in the majority of patients, TEE may prove a useful tool to exclude suspected circumflex occlusion.