Modifications of the Cox-Maze III procedure

Area of Science:

• Cardiac Surgery
• Electrophysiology
• Atrial Fibrillation Ablation

Background:

• The Cox-Maze III procedure (CM-III) is effective but time-consuming, limiting its use as a concomitant operation.
• Post-CM-III, left atrial (LA) contraction recovery is often less robust than right atrial (RA) contraction.

Purpose of the Study:

• To reduce operative time for the Cox-Maze III procedure (CM-III) through modifications.
• To enhance left atrial (LA) contractility following CM-III.
• To compare the efficacy of modified CM-III techniques against the conventional procedure in patients with rheumatic mitral valve disease.

Main Methods:

• Modification I: Simplified atrial incisions, LA appendage obliteration, and extended RA incisions to decrease operative time.
• Modification II: Separate encirclement of pulmonary veins to improve LA contractility.
• Comparison of clinical outcomes, including operative times (aortic cross-clamp and cardiopulmonary bypass) and atrial contractility, between conventional and modified CM-III groups.

Main Results:

• Modification I significantly reduced aortic cross-clamp (ACC) and cardiopulmonary bypass (CPB) times compared to conventional CM-III (p < 0.005 and p < 0.001, respectively).
• Sinus rhythm restoration rates were comparable between groups (88.9% vs. 91.3%).
• Modification II demonstrated significantly increased LA contractility (A velocity and A/E ratio) compared to conventional CM-III (p < 0.05), despite longer ACC times.

Conclusions:

• The first CM-III modification achieves similar sinus conversion and atrial contractility restoration with significantly shorter operative times.
• The second CM-III modification enhances LA contractility but requires longer cross-clamp times.
• Modified CM-III procedures offer potential advantages for concomitant operations and atrial function recovery.