Hemodynamic behavior of stentless aortic valves in long term follow-up

Intermediate-term Outcomes Following a Case Series of Reoperations for Medtronic Freestyle Stentless Aortic Valves

Background

Data are limited on long-term outcomes in patients who have undergone a reoperation following failure of a stentless aortic valve.

Methods

Between 2006 and 2016, a retrospective analysis was performed on 24 patients who underwent open aortic valve replacement surgery for a failed stentless aortic valve prosthesis at Health Sciences North, Sudbury, Ontario, Canada. The primary outcome was a low mortality rate from cardiac-related deaths after 5 years.

Results

All patients underwent insertion of a Medtronic Freestyle bioprosthesis (Minneapolis, MN) implanted using the modified subcoronary technique for their initial operation. The interval from the first operation to the stentless redo surgery ranged from 6 to 13 years. Aortic valve reoperation was performed for structural valve deterioration in 96% (n = 23) of the cases. Reoperations involved a removal of the stented valve leaflets and standard aortic valve replacement within the stentless casing in 20% (n = 5) of the cases, with the remaining cases requiring complete removal of the stentless prosthesis and aortic valve replacement. In those in whom a complete removal of the stentless valve was possible (n = 19), no disruption of the native aortic root occurred, with a 0% rate of conversion to a Bentall procedure. No intraoperative mortality occurred. The 30-day and 10-year operative mortality rates were 4% and 16%, respectively.

Conclusions

Redo surgery for failing stentless valves can be done with relatively low risk and with acceptable long-term outcomes without resorting to root-replacement techniques.

Propensity matched long-term analysis of mechanical versus stentless aortic valve replacement in the younger patient

OBJECTIVES

The choice of prosthesis for aortic valve replacement (AVR) in younger patients remains controversial. Stentless AVR was introduced 3 decades ago, with the aim of better haemodynamics and durability than stented xenografts. The objective of this analysis was to compare the long-term outcomes to mechanical prostheses in younger patients (age ≤60 years).

METHODS

All adult patients who underwent AVR due to aortic valve stenosis and/or insufficiency between 1993 and 2002 were identified. After the exclusion of patients with congenital heart defects, aortic dissections and Ross-procedures, 158 patients with stentless valves and 226 patients with bi-leaflet mechanical valves were finally included in this analysis. Sixty-six patient pairs could be included in a propensity matched analysis. Mortality and morbidity including stroke, bleeding, endocarditis and reoperation were analysed.

RESULTS

Group baseline characteristics and operative data did not differ significantly after propensity matching. Hospital mortality was 0.0% in the stentless and 1.5% in the mechanical group. Total patient years/median follow-up was 2029.1/15.4 years (completeness: 100.0%, range: 0-25 years). After 20 years, actuarial survival was 47.0 ± 6.4% in the stentless and 53.3 ± 6.6% in mechanical group (P = 0.69). Bleeding, endocarditis and stroke occurred rarely and did not differ significantly between groups. After 20 years, actuarial overall freedom-from-reoperation was 45.1 ± 8.2% in the stentless group and 90.4 ± 4.1% in the mechanical group (P < 0.001). Hospital mortality while reoperation was 7.4% in the stentless group and 0% in the mechanical group (P = 1.0).

CONCLUSIONS

Long-term morbidity and mortality of stentless and mechanical aortic valves were statistically not different besides a significantly higher reoperation rate after stentless AVR combined with a probably higher risk of in-hospital mortality. Thus, mechanical AVR should remain the procedure of choice in younger patients.

Aortic Valve Reoperation After Stentless Bioprosthesis: Short- and Long-Term Outcomes

BACKGROUND

Limited data are available regarding outcomes for stentless aortic valve reoperation. The reported reoperative mortality has been unacceptably high.

METHODS

Between 1997 and 2017, a retrospective analysis was performed on 143 patients who underwent open aortic valve reoperations for failed stentless aortic valve bioprostheses. We evaluated both short-term and long-term outcomes on this cohort of patients.

RESULTS

Bicuspid aortic valve was present in 107 of 143 patients (75%) at the time of the initial Freestyle (Medtronic, Minneapolis, MN) procedure, and 120 of 143 patients (84%) underwent a modified inclusion aortic root replacement procedure. The interval from first operation to reoperation was 9 years (range, 5.4 to 11.8), which was significantly shorter for patients with infectious endocarditis (4.1 years; range, 1.8 to 7.1) compared with patients with structural valvular deterioration (10.4 years; range, 8.1 to 12.4, p < 0.001). The median age at the time of reoperation was 59 years (range, 50 to 67). Aortic valve reoperation was performed for structural valve deterioration in 68% cases compared with 32% for infectious prosthetic valve endocarditis. Concomitant surgery included coronary artery bypass (13%), mitral valve surgery (4%), and ascending aorta and arch replacement (42%). The 30-day and inhospital mortality was 1% and 2%, respectively. The composite outcome including myocardial infarction, stroke, new-onset renal failure on hemodialysis, and operative mortality was 4%. The 5-year and 10-year Kaplan-Meier survival after reoperation for failed stentless valve was 83% (95% confidence interval: 73% to 89%) and 57% (95% confidence interval: 36% to 74%).

CONCLUSIONS

Aortic valve reoperation after stentless valve implantation can be performed with low operative mortality and favorable long-term survival.

Surgery for Young Adults With Aortic Valve Disease not Amenable to Repair

Aortic valve replacement is the gold standard for the management of patients with severe aortic stenosis or mixed pathology that is not amenable to repair according to currently available guidelines. Such a simplified approach may be suitable for many patients, but it is far from ideal for young adults considering emerging evidence demonstrating that conventional valve replacement in this cohort of patients is associated with inferior long-term survival when compared to the general population. Moreover; the utilisation of mechanical and bioprosthetic valves can significantly impact on quality and is linked to increased rates of morbidities. Other available options such as stentless valve, homografts, valve reconstruction and Ross operation can be an appealing alternative to conventional valve replacement. Young patients should be fully informed about all the options available - shared decision making is now part of modern informed consent. This can be achieved when referring physicians have a better understanding of the short and long term outcomes associated with every intervention, in terms of survival and quality of life. This review presents up to date evidence for available surgical options for young adults with aortic stenosis and mixed disease not amenable to repair.

Initial Experience with Aortic Valve Replacement via a Minimally Invasive Approach: A Comparison of Stented, Stentless and Sutureless Valves

Background

This study aimed to compare the short-term outcomes of MIS-AVR among 3 different types of biological heart valves.

Material/Methods

Complete data were obtained from 79 patients who underwent MIS-AVR between January 2010 and June 2015. Patients were divided into 3 groups: 27 patients (group A) received Medtronic 3f^® (Medtronic Inc., Fridley, MN, USA), 36 patients (group B) received DokimosPlus^® (LabCor Laboratórios Ltda., Belo Horizonte, Brazil) and 16 patients (group C) received Perceval^® (Sorin Biomedica Cardio S.r.l., Saluggia VC, Italy) valves.

Operative and postoperative parameters such as duration of operation, bypass time, duration of ventilation, morbidity, and mortality were statistically analyzed using the Kruskal-Wallis test. Hemodynamic assessment with transthoracic echocardiography was performed before discharge.

Results

The EuroSCORE II ranged between 0.67 and 6.94 with no significant difference between the groups. The median operative time was 166 min (range 90–230 min) in total, with significantly shorter times in group C (120 min [range 90–200]). The median total ventilation time was significantly lower in group C and significantly higher in group A. Hemodynamic evaluation demonstrated a mean maximal velocity (v_max) over the aortic valve of 2.3 m/s (range 0.9–4.3 m/s) with average mean and peak pressure gradient values of 10 mmHg (range 3–24 mmHg) and 20 mmHg (range 5–42 mmHg), respectively. Group A showed the highest values for v_max (H>5.99).

No significant difference was found regarding duration of hospitalization. Mortality was 3%.

Conclusions

In conclusion, all 3 valves showed good perioperative results, satisfying hemodynamic performance, and low complication rates.

Prognosis after surgical replacement with a bioprosthetic aortic valve in patients with severe symptomatic aortic stenosis: systematic review of observational studies

OBJECTIVE

 To determine the frequency of survival, stroke, atrial fibrillation, structural valve deterioration, and length of hospital stay after surgical replacement of an aortic valve (SAVR) with a bioprosthetic valve in patients with severe symptomatic aortic stenosis.

DESIGN

 Systematic review and meta-analysis of observational studies.

DATA SOURCES

 Medline, Embase, PubMed (non-Medline records only), Cochrane Database of Systematic Reviews, and Cochrane CENTRAL from 2002 to June 2016.

STUDY SELECTION

 Eligible observational studies followed patients after SAVR with a bioprosthetic valve for at least two years.

METHODS

 Reviewers, independently and in duplicate, evaluated study eligibility, extracted data, and assessed risk of bias for patient important outcomes. We used the GRADE system to quantify absolute effects and quality of evidence. Published survival curves provided data for survival and freedom from structural valve deterioration, and random effect models provided the framework for estimates of pooled incidence rates of stroke, atrial fibrillation, and length of hospital stay.

RESULTS

 In patients undergoing SAVR with a bioprosthetic valve, median survival was 16 years in those aged 65 or less, 12 years in those aged 65 to 75, seven years in those aged 75 to 85, and six years in those aged more than 85. The incidence rate of stroke was 0.25 per 100 patient years (95% confidence interval 0.06 to 0.54) and atrial fibrillation 2.90 per 100 patient years (1.78 to 4.79). Post-SAVR, freedom from structural valve deterioration was 94.0% at 10 years, 81.7% at 15 years, and 52% at 20 years, and mean length of hospital stay was 12 days (95% confidence interval 9 to 15).

CONCLUSION

 Patients with severe symptomatic aortic stenosis undergoing SAVR with a bioprosthetic valve can expect only slightly lower survival than those without aortic stenosis, and a low incidence of stroke and, up to 10 years, of structural valve deterioration. The rate of deterioration increases rapidly after 10 years, and particularly after 15 years.