The Nicks–Nunez posterior enlargement in the small aortic annulus: immediate–intermediate results☆

Kyriakos St. Rammos 0 Demetrios G. Ketikoglou 0 George J. Koullias 0 Sotirios G. Tsomkopoulos 0 Charalambos K. Rammos 0 Nikolaos P. Argyrakis 0 0 Department of Thoracic and Cardiovascular Surgery, AHEPA University Hospital, Aristotle University Medical School , Thessaloniki, Greece Objective: 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 (15y220 - 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 cm2 . In addition, mitral valve replacement (MVR) was performed in two patients and coronary artery bypass grafting (CABG) in three (2 graftsypt). 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 710 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) massyg (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 cm2 . The ejection fraction (EF) and the left ventricular enddiastolic 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. 2006 Published by European Association for Cardio-Thoracic Surgery. All rights reserved. 1. Introduction The impact of prosthesispatient mismatch (PPM) after aortic valve replacement (AVR) remains controversial. Previous reports have stated that the use of small mechanical aortic prostheses raises concern about residual left ventricular outflow obstruction, increased pressure gradients, affected left ventricular function without mass regression and associated morbidity and mortality w1,2x. Recent reports support the fact that PPM has a negative impact on survival for young patients and a lesser one for older patients. Although PPM was not important in small patients, Presented at the 55th International Congress of the European Society for Cardiovascular Surgery, St Petersburg, Russian Federation, May 1114, 2006. *Corresponding author. 29 Karolou Diehl str, Thessaloniki 54623, Greece. Tel.: q30 2310 222.021; fax: q30 2310 222.021. E-mail address: (K. St. Rammos). 2006 Published by European Association for Cardio-Thoracic Surgery PPM negatively impacted survival for average and largesize patients with mechanical valves w3,4x. In order to avoid PPM, surgical techniques have evolved for enlargement of the small aortic root. Nicks and associates (1970) w5x and Nunez and associates (1983) w6x proposed a posterior approach for enlargement, either through the non-coronary sinus, across the aortic ring as far as the origin of the mitral valve or by resecting the posterior commissure (between left and non-coronary cusps) with the base of the gap formed by the fibrous origin of the anterior mitral leaflet. Another posterior enlargement technique was introduced by Manougian w7x with the aortotomy extending into the non-coronary sinus, lateral opening of the left atrium and into the anterior leaflet of the mitral valve. Besides the posterior enlargement techniques the Konno w8x and Rastan w9x anterior enlargement (through the right coronary sinus extending into the right ventricular outflow tract) has been K. St. Rammos et al. / Interactive CardioVascular and Thoracic Surgery 5 (2006) 749754 reported in many cases. Recently, a two-directional aortic annular enlargement (combination of posterior and anterior enlargement) w10x and a double-patch technique for posterior enlargement w11x have been reported. The objective of our study was to retrospectively assess the immediate and intermediate results on our patients that have undergone aortic annular enlargement to avoid PPM. 2. Materials and methods During the period November 1995 to June 2005, 220 patients underwent aortic valve replacement (AVR) for primary aortic stenosis (AS) by the same surgeon (KSR). Fifteen of those 220 patients (6%), all women (age 4076 Cor: coronary pathology, N: normal, MVC: mitral valve commissurotomy, CoA: coarctation repair, BW: body weight, BSA: body surface area, Dx: diagnosis, EVOA: effective valve orifice area. years, mean 65.8) with a primary diagnosis of AS, underwent AVR after a posterior enlargement of their small aortic annulus using the NicksNunez procedure. Mean effective aortic valve area was 0.7"0.2 cm2. Twelve women had a body surface area (BSA) -1.7 m2 and were defined as small patients, and three women had a BSA between 1.72.1 m2 and were defined as average. Their body weight (BW) ranged from 45110 kg (mean 66.7 kg). Nine of them were in NYHA class III and 6 in NYHA IV. One patient had AI in addition to AS, another one had a history of closed mitral valve commissurotomy (CMVC), two patients had mitral regurgitation (MR), one had mitral stenosis (MS) and another one had a history of coarctation repair at a younger age (Table 1). Associated surgical procedures performed included: CABG (ns3, 2 graftsypt), K. St. Rammos et al. / Interactive CardioVascular and Thoracic Surgery 5 (2006) 749754 Fig. 1. After the posterior enlargement with synthetic graft, the prosthesis is sewn only under the left and right coronary ostia. Fig. 2. The prosthesis (area of divided non-coronary sinus) is sewn to the appropriate level of the synthetic graft after careful orien (...truncated)