Sutureless aortic valve replacement Though conventional midline sternotomy for AVR is an effective therapy, the development of minimally invasive procedures to decrease surgical risk and improve patient acceptance is particularly important for the elderly high-risk population. Perceval S is a sutureless prosthetic valve comprised of a tissue component valve made from bovine pericardium attached to a self-expanding anchoring device. The anchoring device design is made by dual-ring segments, three commissural elements supporting the valve, and six sinusoidal elements enhancing fixation in the aortic root, sinotubular junction, and sinuses of Valsalva. With the sturdy anchoring device, this sutureless device can ensure good stability with a low risk of coronary compromise and valve migration. Using a sutureless bioprosthetic valve for minimally invasive AVR has become a commonly preferable procedure for patients with aortic stenosis in some European countries.
Reduction in cross-clamp and cardiopulmonary bypass time It is well established in the cardiothoracic surgical literature that extended CPB and aortic cross-clamping times are significant, independent risk factors for mortality and morbidity in patients undergoing cardiac surgery. A retrospective analysis of patients with aortic valve stenosis demonstrated that aortic cross-clamp time was a significant, independent predictor of cardiovascular morbidity. Therefore, any technique that shortens cross-clamp or CPB time has the potential to decrease the risk of complications and improve long-term survival. Due to the efficient deployment system, SU-AVR can dramatically decrease cardiac ischemia time and total surgery duration compared to traditional open-heart surgery. In a meta-analysis reported by Phan et al., SU-AVR had shorter CPB and cross-clamp times with both conventional and minimally invasive approaches according to the Society of Thoracic Surgeons national database. Also, Pollari et al. reported that the shorter procedure time in SU-AVR was associated with a lower rate of postoperative complications, a shorter intubation time, a shorter ICU stay, and reduced hospital costs compared to conventional AVR. In a previous study reported from this institute, the mean cross-clamp and CPB times were 123 ± 53.1 min and 157 ± 78.6 min respectively, and both longer than the data observed in the present study. Besides, it also revealed more extended ICU stay (4.9 ± 7.5 days) and hospital stay (24.1 ± 20.3 days) compared to the present study. In high-risk patients undergoing concomitant cardiac surgery with a prolonged surgical time as well as in patients undergoing reintervention, the use of the sutureless bioprosthesis is even more valuable. Additionally, sutureless implantation with the valve collapsed on a holder requires minimal manipulation of the aortic root and prosthetic valve, which may help avoid potential complications of the root or prosthetic valve endocarditis. Furthermore, with good visibility of the annulus, SU-AVR facilitates a minimally invasive approach either through an upper J-ministernotomy or a right mini-thoracotomy requiring only a 6 cm surgical wound. These benefits decrease postoperative wound pain and hasten the patient's recovery.
Valve hemodynamics and paravalvular leakage TAVI represents the least invasive approach to AVR because it can be performed percutaneously without requiring CPB. However, the main limitation of TAVI is that the native diseased valve tissue cannot be removed. This may cause incomplete attachment of the prosthetic valve on the annulus and lead to a higher incidence of paravalvular leakage compared with that of conventional AVR. Paravalvular leakage is an important complication that always has to be considered when assessing the outcomes of prosthetic valve implantation. Recent evidence from TAVI trials demonstrates a significant correlation between paravalvular leakage and a poorer mid-term survival. The SU-AVR approach ensures a complete excision of the calcified valve in a manner the same as conventional AVR. Furthermore, with SU-AVR the prosthesis is implanted under direct visualization on a non-beating heart, which also reduces the risk of misplacement and paravalvular leakage compared to the angiography-guided deployment used in TAVI. In a meta-analysis reported by Phan et al., the incidence of paravalvular leakage in patients undergoing SU-AVR was only 3%. In the present study, follow-up echocardiography at 6 months postoperatively validated this finding. In addition to a lower risk of a paravalvular leak, a prosthetic valve with a larger profile can be implanted because of the lack of a traditional bioprosthetic valve stent and sutured ring. This results in improved valve hemodynamics compared to that seen with conventional AVR, and avoids a patient/prosthesis mismatch. In the present study, all parameters measured by echocardiography indicated excellent valve hemodynamics and were associated with an improvement in clinical symptoms after SU-AVR.
Study limitations Despite the promising results of this study, several important limitations must be considered. First, the study was a nonrandomized trial without a control group, and there may have been bias in the patient selection. Second, this study includes a limited number of patients, which might influence the complication rates and outcomes. Finally, since this was a prospective study, the follow-up period is short, and an extended follow-up is necessary to evaluate the long-term outcomes in this patient population.
