Annulus-Sparing Tetralogy of Fallot Repair: Low Risk and Benefits to Right Ventricular Geometry.

Background. Annulus-sparing repair of tetralogy of Fallot (TOF) carries a potential increased risk of reoperation for restenosis and unproven benefits on right ventricular (RV) geometry. Methods. Primary TOF repairs (n = 434) between 2000 and 2012 were studied using risk-adjusted parametric techniques. Progression of cardiac dimensions was analyzed using repeated measures regression using reports of all 2,103 echocardiograms undertaken throughout the study period, to a maximum follow-up of 13.7 years. Results. Repair was at a mean age of 180 days: AS approach in 296 (68%) patients; and transannular patch in 138 (32%). Intraoperative revisions (for residual stenosis) were required in 135 patients (29%). There have been 4 deaths (survival 99%). Surgical reoperation for recurrent right ventricular outflow tract stenosis was occasionally required in both groups at comparable rates (transannular patch, 5 of 136 [4%]; annulus-sparing repair, 14 of 296 [5%]; p = 0.83). Larger increases in RV end-diastolic dimensions were evident in transannular patch patients versus annulus-sparing repair patients (p < 0.0001). Other risks for RV dilation included worse grade of postoperative pulmonary regurgitation, larger right ventricular end-diastolic dimension at the time of diagnosis, and higher operative weight (all p < 0.0001). Factors associated with successful annulus-sparing repair included (1) pulmonary annulus greater than 7 mm, right ventricular enddiastolic dimension greater than 1.2 cm, and tricuspid annulus greater than 1.4 cm (all preoperatively); and (2) right ventricular outflow tract diameter greater than 10 mm and right ventricular systolic pressure less than 50 mm Hg (both intraoperatively after repair). Conclusions. Pursuit of annulus-sparing repair strategies can lower the use of transannular patch to approximately 30% with low risk of reoperation for the patient. Annulussparing repair is associated with significantly reduced long-term RV dilation. Pulmonary valve enlargement to approximately 10 mm and right ventricular systolic pressure less than 50 mm Hg during annulus-sparing repair are associated with low risk of recurrent stenosis. (C) 2018 by The Society of Thoracic Surgeons