The Nicks-Nunez posterior enlargement in the small aortic annulus: immediate-intermediate results.

OBJECTIVES To avoid prosthesis-patient mismatch, posterior enlargement of the small aortic annulus using the Nicks-Nunez surgical approach was performed in fifteen patients and the immediate-intermediate results are reported retrospectively. METHODS During the period November 1995 to June 2005, 220 patients underwent aortic valve replacement (AVR) for primary aortic stenosis (AS). Fifteen patients (15/220 - 6%), all women, 40-76 years old (mean age 65.8 years) with AS, underwent AVR applying the Nicks-Nunez posterior enlargement of the small aortic annulus with an effective aortic valve area 0.7+/-0.2 cm(2). In addition, mitral valve replacement (MVR) was performed in two patients and coronary artery bypass grafting (CABG) in three (2 grafts/pt). Endarterectomy of the ascending aorta was performed in one patient. With the exception of one patient, mechanical valves were used. In all cases, transesophageal echo (TEE), normothermic cardiopulmonary bypass (CPB), left ventricular venting, antegrade crystalloid cardioplegic arrest and local myocardial cooling, was used. The defect after the enlargement was closed with autologous pericardium in four and synthetic graft in eleven patients. The follow-up period was 5-120 months (mean 61.5 months). RESULTS There was no operative or hospital mortality. The length of CPB and aortic crossclamping was increased as well as the duration of mechanical ventilation. In one, out of two patients, in whom the decision for enlargement was delayed, intraaortic balloon pump was used. However, there was no other morbidity and the final length of stay was 7-10 days (same as for routine AVR). One patient died five years later from lung cancer. Serial follow-up transthoracic echoes have shown statistically significant improvements in left ventricular-intraventricular septum thickness (LVIVS) (16.5+/-1.3 mm vs. 14.3+/-1.7 mm, P<0.01), left ventricular posterior wall thickness (LVPWT) (16.7+/-1.4 mm vs. 14.5+/-1.8 mm, P<0.01), left ventricular (LV) mass/g (415+/-33 vs. 388+/-41, P<0.01), peak gradient (98+/-10 mmHg vs. 48+/-7 mmHg, P<0.001) and in mean gradient (58+/-10 mmHg vs. 22+/-8 mmHg, P<0.001). The functional aortic valve orifice postoperatively was 1.4+/-0.5 cm(2). The ejection fraction (EF) and the left ventricular end-diastolic pressure (LVEDP) were unchanged. CONCLUSIONS Immediate and intermediate results reveal the safety of the procedure and the significant functional and anatomical improvement of the left ventricle. Although the number of patients is small, female patients, small or large, seem to be the usual candidates for this procedure.