Durability of Porcine Bioroots in Younger Patients With Aortic Root Pathology: A Propensity-Matched Comparison With Composite Mechanical Roots

Outcomes of reoperative aortic root surgery

OBJECTIVE

The study objective was to determine the impact of reoperative aortic root replacement on short-term outcomes and survival.

METHODS

This was a retrospective study of aortic root operations from 2010 to 2018. All patients with a complete aortic root replacement were included, and patients undergoing valve-sparing root replacements were excluded. Patients were dichotomized by first-time sternotomy versus redo sternotomy, which was defined as having had a prior sternotomy for whatever reason. Within the redo sternotomy group, reoperative aortic root replacements were identified, being defined as a complete aortic root replacement in patients with a prior aortic root replacement; 1:1 nearest neighbor propensity matching was used to compare outcomes across groups. Kaplan-Meier survival estimates were generated and compared using log-rank statistics.

RESULTS

A total of 893 patients undergoing complete ARR were identified, of whom 595 (67%) underwent first-time sternotomy and 298 (33%) underwent redo sternotomy. After matching, postoperative outcomes were similar for the first-time and redo sternotomy groups, including operative mortality. Redo sternotomy was not associated with reduced survival after aortic root replacement compared with first-time sternotomy (P = .084), with 5-year survival of 73.7% for first-time sternotomy and 72.9% for redo sternotomy. In the redo sternotomy group (n = 298), 69 (23%) were reoperative aortic root replacements and 229 (77%) were first-time aortic root replacements. After matching, postoperative outcomes were similar for the first-time and reoperative aortic root replacement groups, including operative mortality. Reoperative aortic root replacement was not associated with reduced survival, compared with first-time aortic root replacement (P = .870), with 5-year survival of 67.9% for first-time aortic root replacement and 72.1% for reoperative aortic root replacement.

CONCLUSIONS

Reoperative aortic root replacement can be performed safely and provides similar survival to first-time aortic root replacement.

Structural abnormalities after aortic root replacement with stentless xenograft

OBJECTIVE

In complex and high-risk aortic root disease, the porcine Freestyle stentless bioprosthesis (Medtronic Inc, Minneapolis, Minn) is an important surgical treatment option. We aimed to determine prevalence and clinical effect of structural and functional abnormalities after full-root Freestyle implantation.

METHODS

Our cross-sectional 2-center study combined with clinical follow-up included 253 patients with full-root Freestyle bioprostheses implanted from 1999 to 2017. Patients underwent transthoracic echocardiography (TTE) and contrast-enhanced, electrocardiogram-gated 4-dimensional cardiac computed tomography (4DCT) at median age 70 (interquartile range, 62-75) years. After 4DCT, clinical follow-up continued throughout 2018. Median follow-up was 3.3 years before 4DCT and 1.4 years after.

RESULTS

We identified abnormalities in 46% of patients, including pseudoaneurysms (n = 32; 13%), moderate or severe coronary ostial stenosis (n = 54; 21%), and moderate-severe leaflet thickening or reduced leaflet motion (n = 51; 20%). TTE only identified 1 patient with pseudoaneurysm. After 4DCT, the unadjusted hazard ratio for surgical reintervention among patients with abnormal 4DCT was 4.2 (95% confidence interval, 1.2-15.3), in all, 10% required a reintervention. 4DCT abnormalities were associated with a statistically nonsignificant increased risk of death, stroke, or myocardial infarction (hazard ratio obtained using Cox proportional hazards regression analysis, 2.4; 95% confidence interval, 0.7-7.6). In all, 4.0% died, 3.6% had a myocardial infarction, and 2.0% had a stroke.

CONCLUSIONS

Structural and functional abnormalities of the aortic root are frequent after Freestyle implantation and TTE appears to be insufficient for follow-up. Abnormalities might be associated with increased risk of reintervention and potentially adverse clinical outcomes. Longer follow-up and larger study populations are needed to further clarify the clinical implications of abnormalities identified with 4DCT.

Aortic Root Surgery in Adults: An Unsolved Problem

Nowadays, despite the rapid advancements in interventional cardiology, open surgery still deals with aortic root diseases, to assure the best "ad hoc" treatment. In case of middle-aged adult patients, the optimal operation still represents a matter of debate. A review of the last 10-year literature was conducted, focusing on patients below 65 to 70 years of age. Because of the small sample and the heterogeneity of the papers, no metanalysis was possible. Bentall-de Bono procedure, valve sparing, and Ross operations are the surgical options currently available. The main issues in the Bentall - de Bono operation are lifelong anticoagulation therapy and cavitation in case of mechanical prosthesis implantation and structural valve degeneration in case of biological Bentall. As transcatheter procedures are currently performed as valve in valve, biological prosthesis may be preferable, if the diameter may prevent postoperative high gradients. Conservative techniques, such as remodeling and reimplantation, preferred in the young, guarantee physiologic aortic root dynamics and impose surgical analysis of the aortic root structures to get a durable result. The Ross operation, which shows excellent performance, involves autologous pulmonary valve implantation and is performed only in experienced and high-volume centers. Due to its technical difficulty, it requires a steep learning curve and presents some limitations in specific aortic valve diseases. All three have advantages and downsides, and no ideal solution has still been reported.

Midterm Outcomes of Stented Versus Stentless Bioprosthetic Valves After Aortic Root Replacement

To determine the impact of aortic root replacement (ARR) with a stentless bioprosthetic valve on midterm outcomes compared to a stented bioprosthetic valve-graft conduit. This was an observational study of aortic root operations from 2010 to 2018. All patients with a complete ARR for nonendocarditis reasons were included, while patients undergoing valve-sparing root replacements or primary aortic valve replacement or repair were excluded. Of the patients with a complete ARR, bioprosthetic valve implants were included, while mechanical valve implants were excluded. Patients were dichotomized into the stented ARR group and the stentless ARR group. A total of 1:1 nearest neighbor propensity matching was employed to assess the association of stentless valves with short-term and midterm outcomes. A total of 455 patients underwent a complete ARR with a bioprosthetic valve implant for nonendocarditis reasons, of which 212 (46.6%) received a stented valve, while 243 (53.4%) received a stentless valve. After matching, postoperative outcomes were similar across each group (P > 0.05), including operative mortality and adverse neurologic events. Median follow-up for the entire cohort was 4.41 years (95% CI: 4.01, 4.95). At 1 year follow-up, aortic regurgitation ≥ 2+ and ejection fraction were similar across each group (P > 0.05); however, the stentless valve group had lower aortic valve velocity and transvalvular pressure gradient. Finally, reoperations and survival were similar for each group over the study's follow-up (P > 0.05). Stentless valves may provide hemodynamic benefits after ARR; however, the clinical impact of those benefits for survival and reoperation may not yet be evident in the midterm.

Perspective. Reoperative Bentall: choice of conduits

The Bentall procedure represents the gold standard in the treatment of patients requiring aortic root replacement. The most common indications for redo Bentall are structural degeneration or graft infection. Redo aortic root replacement can be performed with low perioperative morbidity and death. The choice of the best conduit is still up for debate but is mandatory to guarantee the best and most durable option for the patient. New options are available to reduce mortality in older or fragile patients and can modify the conduit choice.

Novel Treatment of a Degenerated Bioroot With the Use of the Sutureless Valve Technique

We describe 3 patients with severe aortic regurgitation after aortic root replacement using the Freestyle bioprosthesis (Medtronic, Minneapolis, MN). The indication in 2 patients was endocarditis. The third patient showed rupture of the right coronary cusp. To achieve fewer complications, lower operative risk, and reduce operative and cross-clamp times, implantation of a sutureless bioprosthesis in a valve-in-valve manner was performed. A Perceval bioprosthesis (Sorin Biomedica Cardio Srl, Sallugia, Italy) was used in 2 patients, and a 3F Enable bioprosthesis (Medtronic) was used in the other patient. No perioperative complications or in-hospital deaths were observed. We conclude that sutureless aortic valve prostheses offer a safe and feasible option for management of failed homografts.

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.

Outcomes of aortic root replacement after previous aortic root replacement: the "true" redo root

BACKGROUND

Aortic reoperations are technically challenging. This study evaluated outcomes after "true" redo root replacement (previous full root replacement) stratified by cause of prosthesis failure.

METHODS

Data were compared for 793 patients who underwent a first-time sternotomy (de novo group) and 120 patients who had previously undergone full aortic root replacement (redo group), of which 76 underwent reoperation due to structural valve deterioration (degenerative group), and 44 due to endocarditis (infection group).

RESULTS

Overall mortality was 4% (n = 28) in the de novo group and 5% (n = 6) in the redo group (p = 0.43) (degenerative group, 3%, infection group, 9%; p = 0.19). The infection group had an increased incidence of renal failure, sternal infection, prolonged ventilation, reoperation for bleeding, multisystem failure, and sepsis, and an increased hospital length of stay. The degenerative group and the de novo group had a similar risk of perioperative death and major complications. The 5-year survival was 86.3% ± 1.3% for the de novo group and 77.3% ± 4.6% for the redo group (p ≤ 0.01; degenerative, 86.3% ± 5%; infection, 65.3% ± 7.7%; p < 0.01; p = 0.98 for de novo vs degenerative). Multivariate analysis demonstrated that reoperation for degenerative failure did not increase the risk of perioperative or late death.

CONCLUSIONS

Redo aortic root replacement can be performed with low perioperative morbidity and death. The presence of infection increases the risk of complications and worsens survival. However, redo root replacement for degenerative failure can be performed with similar short-term complication risk and midterm survival as de novo root replacement.

Reoperation for failure of freestyle bioprosthesis using an Edwards intuity valve

We report the first case of a successful implantation of the new Edwards Intuity rapid-deployment bioprosthesis in a 50-year-old man with acute failure of a Freestyle Medtronic root with severe aortic regurgitation and massive calcification of the root and both coronary buttons.

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

BACKGROUND

Stentless porcine bioroots and pericardial composite roots were developed as prostheses that avoid the anticoagulation necessary for mechanical composite roots. Data on the hemodynamics of all root replacements are lacking and questions remain regarding comparative performance.

METHODS

This study evaluated patients receiving a stentless porcine bioroot, a pericardial, or a mechanical composite root at a single institution from January 2000 to December 2008. All patients underwent preoperative, postoperative and greater than 1-year echocardiograms. All root replacements were performed for aortic insufficiency or aneurysm. Median follow-up was 3.3 years (1 to 8 years).

RESULTS

There were no significant differences in preoperative left ventricular ejection fraction, aortic valve peak gradient, mean gradient, left ventricular end diastolic diameter, and left ventricular end systolic diameter. Postoperative peak and mean gradients in mechanical composite roots were significantly higher than stentless porcine bioroots. At greater than 1 year, stentless porcine bioroots had significantly lower peak and mean gradients than both mechanical composite roots and pericardial composite roots. The end diastolic diameter was also significantly smaller in stentless porcine bioroots at greater than 1 year than mechanical composite roots.

CONCLUSIONS

All prostheses resulted in favorable hemodynamic and ventricular remodeling. Stentless porcine bioroots had the lowest gradients at greater than 1 year of all root replacements, with significantly better ventricular remodeling when compared with mechanical composite roots. Pericardial roots also had favorable hemodynamics and ventricular remodeling, suggesting that they are a viable alternative.