Minimally invasive aortic valve replacement: 12-year single center experience

Abstract

Background: This study reports the single center experience on minimally invasive aortic valve replacement (MIAVR), performed through a right anterior minithoracotomy or ministernotomy (MS).

Methods: Eight hundred and fifty-three patients, who underwent MIAVR from 2002 to 2014, were retrospectively analyzed. Survival was evaluated using the Kaplan-Meier method. The Cox multivariable proportional hazards regression model was developed to identify independent predictors of follow-up mortality.

Results: Median age was 73.8, and 405 (47.5%) of patients were female. The overall 30-day mortality was 1.9%. Four hundred and forty-three (51.9%) and 368 (43.1%) patients received biological and sutureless prostheses, respectively. Median cardiopulmonary bypass time and aortic cross-clamping time were 108 and 75 minutes, respectively. Nineteen (2.2%) cases required conversion to full median sternotomy. Thirty-seven (4.3%) patients required re-exploration for bleeding. Perioperative stroke occurred in 15 (1.8%) patients, while transient ischemic attack occurred postoperative in 11 (1.3%). New onset atrial fibrillation was reported for 243 (28.5%) patients. After a median follow-up of 29.1 months (2,676.0 patient-years), survival rates at 1 and 5 years were 96%±1% and 80%±3%, respectively. Cox multivariable analysis showed that advanced age, history of cardiac arrhythmia, preoperative chronic renal failure, MS approach, prolonged mechanical ventilation and hospital stay as well as wound revision were associated with higher mortality.

Conclusions: MIAVR via both approaches is safe and feasible with excellent outcomes, and is associated with low conversion rate and low perioperative morbidity. Long term survival is at least comparable to that reported for conventional sternotomy AVR.

Keywords: Aortic valve replacement (AVR); heart valve prosthesis; minimally invasive heart surgery; outcomes.

Figure 1

Chest computed tomography scan as a tool for minimally invasive approach choice. White vertical dotted line is a virtual reference, corresponding to the right margin of the sternal bone, and determines the position of the ascending aorta in relation to the sternum. (A) Retrosternal position of the ascending aorta (not favorable for RAMT); (B) quite dextrapositioned ascending aorta (favorable for RAMT); (C) an example of a deep thorax (the distance to ascending aorta from anterior chest measures 10.2 cm); (D) another example of a deep thorax (the distance to ascending aorta from anterior chest measures 12.1 cm).

Figure 2

Survival function curve in the overall cohort.

Figure 3

Survival function at mean of covariates by Cox multivariable proportional hazards regression model. Overall study population data on 853 patients.