4. Discussion
Multiple non-randomized studies, meta-analyses and registry have shown that Sutureless rapid deployment aortic tissue valve is safe and effective alternate to conventional SAVR and associated with improved clinical outcomes.
In majority of published studies on Perceval valve, the average age of patient was > 75 years, where as in our study the average age was 67.3 ± 13.8 years. Major advantage of Perceval sutureless valve was observed in intermediate and high risk group (15,16) whereas in our study all patients were in low or intermediate risk group with average STS score of 2.71 ± 1.54.
Various studies have demonstrated that duration of aortic x-clamp and CPB are independent predictors of survival after valve replacement and combined valve operation with CABG (17). In our study the average x-clamp time of 42 ± 11 minutes in isolated aortic valve and 74 ± 23 minutes in combined procedures. The CPB time was 54±14 minutes in isolated AVR and 101±36 in combined procedures. We observed 18% reduction in x-clamp time and 22% reduction in CPB time when we compared it with standard bio-prosthetic sutured valve by same surgeon. In CABG + AVR patient all distal anastomosis were done on pump beating heart which further reduced the x-clamp time.
Recently published Persist AVR trial has shown 30% reduction in x-clamp time and 20-25% reduction in CPB time by using Perceval in comparison of standard AVR in isolated AVR surgery (18).
In our experience we could perform MIAVR in 12 out of 19 isolated AVR patients. In SURD-IR registry it was observed that less invasive approach was used in two third of study patients and in 50% high risk patients, with good intermediate results in all risk categories (19).
In our study also we did not find any significant difference in x-clamp and CPB time between sternotomy AVR and MIAVR with use of Perceval, but the patient number are less to reach to a real conclusion.
There was no PVL in any of our patients. The vast majority of published reports shown very low rate of moderate to severe PVL (21) with proper decalcification, sizing and valve positioning, PVL is comparable with standard SAVR (14).
The rate of permanent pacemaker implantation has been a bit of concern with the Perceval. The majority of the literature reports of PPI between 6% and 9%. However some studies have reported rate as high as 23% (22). In order to avoid PPI, the key points are (i) proper decalcification of the annulus, (ii) correct sizing and certainly avoid over sizing, (iii) proper placement of guiding sutures, (iv) Adjusting balloon inflation between 2to 4mmHg (15), by using these modified guidelines we have noticed significant improved in rate of PPI.
4 patients developed new onset LBBB in immediate post-operative period. In two patients, it was recovered to normal EKG in ICU where as in 2 patients it was persisted in follow-up. One patient with preexisting RBBB had complete heart block in immediate post-operative period requiring temporary pacing but it was recovered on 6thpost-operative day. 2 patients developed new onset LBBB post implant which was persistent during follow-up. We had 2.4 ± 1.1 and 3.9 ± 1.6 days ICU stay and 6.7 ± 1.2 and 10.9 ± 2.4 days hospital stay in isolated AVR and combined procedure respectively. In these small number of patients we did not find much difference in ICU and hospital stay when compare to standard sutured aortic valve. Multiple studies have reported decrease in ICU stay and blood transfusions with use of Perceval sutureless valve in isolated AVR (23). Marco Solinas et al reported reduction of ICU and hospital stay by adding Perceval valve and right anterior thoracotomy(20). In an international prospective registry statistically significant difference was noticed in ICU and hospital stay by using sutureless valve and MIAVR approach (24).
Rate of intraoperative stroke range from 0 to 5% for the Perceval and 2.5 to 5% for TAVI (26, 27). Data from Partner II trial and German registry indicates that the incidence of PVL after TAVI is significantly higher when compared with Sutureless aortic valve (28). SURD-IR registry has shown that in low risk patients, the mortality rate was lower in sutureless valve then that recorded in the NOTION trial 1.55 vs 2.1% (29). The most important piece of data concerns to patients deemed at very high risk, a patient population comparable to that included in the PARTNER trial cohort B (6). In this trial in hospital mortality was 2 fold higher than that observed in SURD-IR registry for sutureless valve (2.6% vs 5%) (19).
In two female patients with small aortic annulus, small size Perceval valve was implanted. Both patient showed excellent valve hemodynamics in post-operative period with no patient prosthesis mismatch.
In our limited experience, morbidity was low and we did not have any mortality even in follow-up. SURD-IR registry has compared the morbidity and mortality in patients undergoing sutureless rapid deployment valve and they found a extremely satisfactory results even in high risk (EURO score > 10 - 20%) and very high risk (EURO score > 20%) patients (19).
We noticed stable hemodynamics and satisfactory gradient in all our patients at 6 months and 1 year follow-up and none of our patient developed central or PVL.
The health economics of Perceval sutureless valve is highly dependent on the healthcare system, however the ability to facilitate MI surgery will enhance its cost effectiveness by reducing ICU stay, hospital stay and blood usage. Especially in high risk patients using sutureless valve instead of TAVI will further reduce the prosthesis cost (11).