The Effect of Cryo-Maze Procedure on Early and Intermediate Term Outcome in Mitral Valve Disease: Case Matched Study

BACKGROUND: The maze procedure is an effective way to treat atrial fibrillation (AF) associated with mitral valve disease. In a last several years, cryoablation was substituted for atrial incision in many reports to simplify the maze procedure. However, there has been no comparative study to delineate the feasibility of the use of cryoablation. METHODS AND RESULTS: We compared the early and intermediate-term results of the maze procedure including pulmonary venous isolation from the left atrium using cryoablation (CM) with our conventional (Kosakai) maze procedure (KM) including encircling incision around the orifices of pulmonary veins. One hundred and 10 pairs of patients were matched in the age, left atrial dimension >70 mm, duration of AF >0 years, previous cardiac surgery, mechanical valve implantation and concomitant aortic valve procedures. CM required significantly shorter cardiopulmonary bypass time (186+/-56 minute versus 214+/-47 minute, P=0.001) and aortic cross-clamp time (134+/-43 minute versus 144+/-37 minute, P=0.03) than KM with less chest tube drainage (590+/-353 mL versus 745+/-618 mL, P=0.02) for 12 hours after operation. The sinus rhythm restoration rate in CM group (85.4%) was comparable with KM group (86.4%) at discharge. In the late results, the actuarial freedom from recurrence of sustained AF at 3 years in CM group (97.7%) was not significantly (P=0.11) different from that in KM group (90.4%). The actuarial freedom from stroke at 3 years in CM group was 99.0%. CONCLUSION: The modification of the maze procedure including cryoablation for pulmonary venous isolation provided less aortic cross-clamp time and less amount of chest tube drainage with the comparable recovery and maintenance of sinus rhythm with KM. CM is a reliable and less invasive surgical option for the AF associated with mitral valve disease.