LONG-TERM RESULTS OF THE CORRIDOR OPERATION FOR ATRIAL-FIBRILLATION

Objective-To investigate the long-term results of the corridor operati on in the treatment of symptomatic atrial fibrillation refractory to d rug treatment. Background-The corridor operation is designed to isolat e from the left and right atrium a conduit of atrial tissue connecting the sinus node area with the atrioventricular node region in order to preserve physiological ventricular drive. The excluded atria can fibr illate without affecting the ventricular rhythm. This surgical method offers an alternative treatment when atrial fibrillation becomes refra ctory to drug treatment. Patients-From 1987 to 1993, 36 patients with drug refractory symptomatic paroxysmal atrial fibrillation underwent s urgery. The in hospital rhythm was followed thereafter by continuous r hythm monitoring and with epicardial electrograms. After discharge Hol ter recording and stress testing were regularly carried out to evaluat e the sinus node function and to detect arrhythmias; whereas Doppler e chocardiography was used to measure atrial contraction and size. Main outcome measures-Maintained absence of atrial fibrillation without dru g treatment after operation; preservation of normal chronotropic respo nse in the sinus node. Results-The corridor procedure was successful i n 31 (86%) of the 36 patients. After a mean (SD) follow up of 41 (16) months 25 (69%) of the 36 patients were free of arrhythmias without ta king drugs (mean (SE) actuarial freedom at four years 72 (9)%)). Parox ysmal atrial fibrillation recurred in three patients; paroxysmal atria l flutter (two patients) and atrial tachycardia (one patient) develope d in the corridor in three others. Among the 31 patients in whom the o peration was successful sinus node function at rest and during exercis e remained undisturbed in 26 and 25 patients respectively (mean (SE) a ctuarial freedom of sinus node dysfunction at four years (81(7)%)). Pa cemakers were needed in five (16%) of the 31 patients for insufficient sinus node rhythm at rest only. Doppler echocardiography showed maint enance of right atrial contribution to right ventricle filling in 26 o f the 31 patients after operation in contrast to the left atrium, whic h never showed such contribution. His bundle ablation was performed an d a pacemaker implanted in the five patients in whom the corridor oper ation was unsuccessful. Conclusion-These results substantiate the idea of this surgical procedure Modification of the technique is, however, needed to achieve a reliable isolation between left atrium and corrid or, which would make this experimental surgery widely applicable in th e treatment of drug refractory atrial fibrillation.