Comparing aortic root replacements: porcine bioroots versus pericardial versus mechanical composite roots: hemodynamic and ventricular remodeling at greater than one-year follow-up

Mid-term single-center outcomes of BioIntegral compared to Freestyle aortic conduit implantation

BACKGROUND

Full aortic root replacement with biological conduit has limited options. This non-randomized cohort study aims to compare mid-term clinical and hemodynamic results of the BioIntegral (BI) composite biological versus the stentless Freestyle (FS) conduits in patients undergoing full aortic root replacement.

METHODS

From February 2013 to July 2017, 265 patients underwent aortic root replacement at a single institution (202 BI, 65 FS). Preoperative, intraoperative and postoperative parameters, complications including stroke, myocardial infarction (MI), endocarditis and reoperation were studied. Hemodynamic performance of both conduits was analyzed by echocardiography. Target endpoints were 30-day mortality, two-year survival, two-year freedom from major adverse valve-related and cardiovascular events.

RESULTS

Wider BI conduits were used (BI 27±2 vs. FS 25±2 mm, P<0.0001). The BI group had shorter cardiopulmonary bypass (BI 165±67 vs. FS 200±78 min, P<0.0001) and cross-clamp (BI 102±36 vs. FS 122±40 min, P=0.001) times. Thirty-day mortality was similar in both groups. There were fewer conduit-related reoperations in the BI group (BI 0% vs. FS 3%, P=0.012) but higher postoperative atrial fibrillation (BI 31% vs. FS 17%, P=0.025). No significant differences were observed for stroke (BI 5% vs. FS 10%, P=0.947), MI (BI 3% vs. FS 4%, P=0.583), or infective endocarditis (BI 0% vs. FS 2%, P=0.077). No significant hemodynamic differences were evident on follow-up echocardiography while an improved overall survival trend was seen in the BI group (P=0.062).

CONCLUSIONS

FS and BI provide comparable clinical mid-term results and hemodynamic parameters. Simplified implantation technique providing shorter cardiopulmonary bypass and operation times are advantageous for BI.

Current indications for stentless aortic bioprostheses

The best aortic prostheses have been debated for decades. The introduction of stentless aortic bioprostheses was aimed at improving hemodynamics and potentially the durability of aortic bioprostheses. Despite the good short- and long-term outcomes after implantation of stentless aortic bioprostheses, their use remains limited owing to the technically demanding implantation techniques. Nevertheless, stentless aortic bioprostheses might be of special benefit in certain indications, where they could be a valuable addition to the surgical armamentarium.

Left ventricular reverse remodeling after aortic valve surgery for acute versus chronic aortic regurgitation

AIMS

Extent of left ventricular (LV) reverse remodeling after aortic valve repair or replacement (AVR) may differ between patients operated for acute aortic regurgitation (AR) and chronic AR. The aim of this study was to compare changes in LV volumes and function between patients with acute and chronic AR who underwent AVR.

METHODS AND RESULTS

A total of 98 patients (54±15 years, 61% men) with acute (n=21) or chronic AR (n=77) were included in the present retrospective evaluation. LV volumes, LV ejection fraction, and global longitudinal strain indexed for LV end-diastolic volume (GLSi) were assessed preoperatively and after a median follow-up of 28 months (interquartile range: 17-66 months). Patients with acute AR tended to have smaller preoperative LV end-diastolic volume compared with chronic AR (156±15 vs 183±6 mL; P=.070). Both in patients with acute and chronic AR, significant LV reverse remodeling with sustained reduction in LV volumes occurred during follow-up with a significant smaller LV end-diastolic volume in acute AR compared with chronic AR (106±8 vs 128±5 mL; P=.032). Preoperative and postoperative LV ejection fractions were not significantly different between groups. In contrast, GLSi was better in patients with acute AR compared with chronic AR before AVR (-1.34±0.20 vs -0.96±0.07%/10 mL; P=.042) and during follow-up (-1.65±0.16 vs -1.29±0.07%/10 mL; P=.017).

CONCLUSIONS

After AVR, LV reverse remodeling occurs both in patients with acute and chronic AR. However, LV end-diastolic volume was more reduced and GLSi was more preserved during follow-up in acute AR than in chronic AR.

At the Root of the Repair Debate: Outcomes After Elective Aortic Root Replacements for Aortic Insufficiency With Aneurysm

BACKGROUND

There is growing interest in aortic valve-sparing and valve repair operations, but the ideal operation and timing of intervention in these generally younger patients undergoing operations for aortic insufficiency (AI) and dilated ascending aorta remains controversial.

METHODS

Root replacements at a single institution from 2002 to 2014 were reviewed. Inclusion criteria were age younger than 70 and presence of moderate or greater aortic insufficiency (AI), with or without aortic aneurysm. Of 1,425 root replacements, 220 patients were considered in the final analysis.

RESULTS

Moderate AI was present in 87 patients and severe AI in 133 patients. The 30-day mortality was 0% in moderate AI patients and 2% (n = 3) in severe AI patients (p = 0.3). Freedom from reoperation was 95% at 10 years. Severe preoperative AI was associated with worse long-term survival compared with moderate AI (hazard ratio, 2.6; p = 0.04). Patients undergoing root replacement with moderate AI had similar survival compared with the age- and gender-matched United States population (log-rank p = 0.93), whereas patients with severe AI had significantly worse survival (log-rank p = 0.02). Other multivariable predictors of decreased long-term survival were age (hazard ratio, 1.1; p = 0.01) and preoperative renal failure (hazard ratio, 6.9; p < 0.01).

CONCLUSIONS

Elective root replacement operations in patients younger than 70 are associated with low rates of mortality and reoperation, which should be considered the benchmark operation for aortic valve-sparing or repair operations in similar patients. Worse survival was associated with severe AI and older age, suggesting earlier intervention may be an appropriate therapeutic strategy in selected patients.

Long Term Outcomes Following Freestyle Stentless Aortic Bioprosthesis Implantation: An Australian Experience

BACKGROUND

The Freestyle stentless bioprosthesis (FSB) has been demonstrated to be a durable prosthesis in the aortic position. We present data following Freestyle implantation for up to 10 years post-operatively and compare this with previously published results.

METHODS

A retrospective cohort analysis of 237 patients following FSB implantation occurred at five Australian hospitals. Follow-up data included clinical and echocardiographic outcomes.

RESULTS

The cohort was 81.4% male with age 63.2±13.0 years and was followed for a mean of 2.4±2.3 years (range 0-10.9 years, total 569 patient-years). The FSB was implanted as a full aortic root replacement in 87.8% patients. The 30-day all cause mortality was 4.2% (2.0% for elective surgery). Cumulative survival at one, five and 10 years was 91.7±1.9%, 82.8±3.8% and 56.5±10.5%, respectively. Freedom from re-intervention at one, five and 10 years was 99.5±0.5%, 91.6±3.7% and 72.3±10.5%, respectively. At latest echocardiographic review (mean 2.3±2.1 years post-operatively), 92.6% had trivial or no aortic regurgitation. Predictors of post-operative mortality included active endocarditis, acute aortic dissection and peripheral vascular disease.

CONCLUSIONS

We report acceptable short and long term outcomes following FSB implantation in a cohort of comparatively younger patients with thoracic aortic disease. The durability of this bioprosthesis in the younger population remains to be confirmed.

Long-term results after aortic root replacement using self-assembled valve composite grafts in patients with small aortic annulus

OBJECTIVES

The study was aimed to evaluate operative and long-term results after complete root replacement using self-assembled valve composite grafts in patients with a small aortic annulus.

METHODS

Among 547 consecutive patients who received the Bentall procedure between 2000 and 2012, a total of 29 patients (61 ± 10; range 42-79 years) had an annulus of ≤20 mm (mean 19.0 ± 0.9). Patients with a native aortic valve (22) suffered from stenosis, insufficiency or mixed defect in 10, 10 and 2 cases, respectively. Among the remaining 7 patients with an artificial aortic valve, there were 3 symptomatic prosthesis-patient mismatches, 3 valve prosthesis deteriorations (1 structural and 2 none-structural) and 1 paravalvular leak. Indication for aortic root replacement was true or false aneurysm, porcelain aorta and intraoperative aortic wall injury in 17, 6 and 6 patients, respectively.

RESULTS

The composite graft for complete aortic root replacement was assembled using a mechanical (26) or biological (3) valve prosthesis placed inside a vascular graft with a median size of 24 (range 22-26) mm. The margin of the tube beneath the valve was anastomosed to the aortic annulus, and coronary ostia were implanted in the usual manner. The mean transvalvular gradient at discharge was 10.8 ± 3.9 mmHg and remained virtually unchanged at the follow-up completed for all patients. Early mortality was 0. During the mean follow-up of 95.8 ± 43.7 months, 2 patients died (54 and 146 months after surgery) due to pulmonary embolism and myocardial infarction, respectively.

CONCLUSIONS

In patients with a small aortic annulus who need complete aortic root replacement, an oversizing of the valve can be easily achieved using modified, self-assembled composite grafts. Offering excellent haemodynamic characteristics, these grafts lead to prevention of prosthesis-patient mismatch and result in very good and durable functional and clinical results.