Root replacement with stentless Freestyle bioprostheses for active endocarditis: a single centre experience

The Freestyle Valve in Severe Necrotizing Aortic Root Endocarditis: Comorbidity Upon Outcome

BACKGROUND

Treatment of severe necrotizing aortic root endocarditis (SNARE) carries a substantial perioperative risk. As an alternative to homografts, we assessed short-term outcome and future prognosis in patients undergoing root replacement using the Freestyle valve.

METHODS

Between 2000 and 2018, a total of 45 patients (mean age 70.9 ± 8.3 years, 66% men) underwent aortic root replacement for SNARE using the Freestyle valve. Mean Society of Thoracic Surgeons mortality score and EuroScore II were 22.6% ± 17.1 and 29.3% ± 20.9, respectively. Prosthetic endocarditis was present in 70.1%, and aortic annulus patch repair was performed in 64% of the patients. Median follow-up was 3.6 years (range: 0.1-14.5) and was 100% complete.

RESULTS

The 30-day mortality was 15.5%. During follow-up, there were no reoperations, while reinfection was suspected in one patient. Survival was significantly inferior to the general population with a standardized mortality ratio of 10.7 (95% confidence interval [CI]: 9.1-12.6) (p < 0.0001). In 30-day survivors and after correction for significant comorbidities in a Cox proportional hazards model, estimated survival probabilities at 1, 5, and 10 years were 98.7 (95% CI: 92.5-99.8%), 94.1 (77.9-98.5%), and 63.8 (28.4-85.2%). Estimated mean difference in survival probability was better for the general population after postoperative year 6, but within the 95% CI for no difference.

CONCLUSION

Use of the Freestyle valve is reliable solution for the most complex cases with a low rate of reinfection. Early mortality is substantial and caused by the patient's condition and severity of the infection. Excess late mortality can be attributed to patient-specific comorbidities.

Freestyle aortic root prosthesis in combination with aortic replacement and open anastomosis: a retrospective analysis

BACKGROUND

The Freestyle® bioprosthesis is used for pathologies of the aortic root. Additional resection of the ascending aorta and the proximal arch in dissections or aneurysms might be indicated. The aim was to assess mid-term outcome regarding prosthetic performance, stroke, reoperations, and survival in various pathologies comparing patients with and without additional procedures on the ascending aorta and proximal arch focusing on the standardised technique of unilateral antegrade cerebral perfusion under moderate hypothermia.

METHODS

Retrospective data analysis of 278 consecutive patients after Freestyle® root replacement between September 2007 and March 2017. Patients were divided in three categories due to the pathology of the aortic root (re-operation vs endocarditis vs dissection). Two groups based on the aortic anastomosis technique (open arch anastomosis (OA) versus non-open arch anastomosis (non-OA) were compared (119 OA vs 159 non-OA). Cardiovascular risk, previous cardiac events, intra- and postoperative data were evaluated. Inferential statistics were performed with Mann-Whitney U-test. Nominal and categorical variables were tested with Fisher-Freeman-Halton exact test. Kaplan-Meier estimate was used to assess survival.

RESULTS

The follow-up rate was 90% (median follow-up: 39.5 months). There were differences in the indication (endocarditis: OA 5 (4.2%) vs non-OA 36 (24%), p < 0.0001; dissection: OA 13 (10.9%) vs non-OA 2 (1.3%); p = 0.0007). OA patients had less perioperative stroke (1 (1%) vs 15 (10%), p = 0.001) and shorter hospital stay (9 vs 12 days, p = 0.0004). There were no differences in the mortality (in-hospital: OA 8 (7%) vs non-OA 8 (5%); p = 0.6; death at follow-up: OA 5 (5%) vs non-OA 15 (11%); p = 0.1). Overall valve performance showed a well-functioning valve in 97.3% at follow-up.

CONCLUSION

The valve performance showed excellent results regardless of the initial indication. The incidence of stroke was lower in patients receiving an open arch anastomosis using unilateral antegrade cerebral perfusion without elevated mortality or prolonged hospital stay.

Revisiting the guidelines and choice the ideal substitute for aortic valve endocarditis

Aortic valve replacement is the most commonly performed cardiac surgical operation worldwide for infective endocarditis (IE). Long-term durability and avoidance of infection relapse are the treatment goals. However, no detailed guidelines on prosthesis selection and surgical strategy are available. Management should be guided by a comprehensive evaluation of infection extension and its microbiological characteristics, the clinical profile of the patient and the risk of infection recurrence. We conducted a literature search of the PubMed database, EMBASE and Cochrane Library (through November 2019) for studies reporting to the use of biological substitutes in aortic valve endocarditis (AVE). Studies comparing long-term outcomes in the use of allogenic and autologous with conventional prostheses were investigated. Conventional mechanical or stented xenografts are the preferred choice for localized aortic infection. In cases of complex IE with the involvement of the root or the aorto-mitral continuity, the use of homografts are recommended, according to surgeon's and center experience. Homograft use needs to be balanced against the risk of structural degeneration. Prosthetic bioroot or prosthetic valved conduit with a mechanical or bioprosthetic valve are acceptable alternatives. The choice of aortic valves substitute and surgical strategy in IE is multifaceted. Principles guiding the selection of prosthesis and surgical approach rely on the long-term durability and the avoidance of infection relapse. A decisional algorithm considering the extension of the infection and its microbiological characteristics, the clinical profile of the patient and the risk of infection recurrence is provided. A multidisciplinary effort is required to achieve consistent outcomes.

Stentless Root Replacement versus Tissue Valves in Infective Endocarditis - A Propensity-Score Matched Study

Introduction

People with aortic/prosthetic valve endocarditis are a high-risk cohort of patients who present a challenge for all medically involved disciplines and who can be treated by various surgical techniques.

Methods

We analyzed the results of treatment of root endocarditis with Medtronic Freestyle® in full-root technique over 19 years (1999-2018) and compared them against treatment with other tissue valves. Comparison was made with propensity score matching, using the nearest neighbor method. Various tests were performed as suited for adequate analyses.

Results

Fifty-four patients in the Medtronic Freestyle group (FS group) were matched against 54 complex root endocarditis patients treated with other tissue valves (Tissue group). Hospital mortality was 9/54 (16.7%) in the FS group vs. 14/54 (25.6%) in the Tissue group (P=0.24). Cox regression performed for early results demonstrated coronary heart disease (P=0.004, odds ratio 2.3), among others, influencing early mortality. Recurrent infection was low (1.8% for FS and Tissue patients) and freedom from reoperation was 97.2% at a total of 367 patient-years of follow-up (median of 2.7 years).

Conclusion

The stentless xenograft is a viable alternative for treatment of valve/root/prosthetic endocarditis, demonstrating a low rate of reinfection. The design of the bioroot allows for complex reconstructive procedures at the outflow tract and the annular level with at an acceptable operative risk. Endocarditis patients can be treated excluding infective tissue from the bloodstream, possibly with benefits, concerning bacteremia and recurrent infection. Furthermore, the use of the stentless bioroot offers varying treatment options in case of future valve degeneration.

Use of the Medtronic Freestyle for aortic valve infection: A retrospective propensity score matched analysis

BACKGROUNDS

Aortic valve and prosthetic valve endocarditis present a challenging subgroup of patients at high risk. We analyzed our experience using the Medtronic Freestyle in full root technique for the treatment of these cases over 18-year time period.

METHODS

We investigated the endocarditis subgroup from our cohort of 971 patients and compared results against other valve types with propensity score matching implementing nearest neighbor method. T-test, χ² test, logistic regression, and Cox regression were performed.

RESULTS

Fifty-four patients from the Freestyle group (FS) were matched against 54 patients from a cohort of 376 aortic valve/root endocarditis patients treated by other valve types (non-FS). Hospital mortality was 9/54 (16.7%) in the FS vs 13/54 (24.1%) in the non-FS group (P = .33). Variables age (P = .003) and renal impairment (P = .026) had an impact on mortality according to Cox regression analysis for early results. Variables with significant risk for long-term mortality included postoperative renal impairment (P = .0001) and multiorgan failure (P = .0001). Recurrent infection was low (1.8% for FS and 3.7% for non-FS group), and freedom from reoperation was 97.2%. Use of the Medtronic Freestyle was no significant risk factor for long-term mortality.

CONCLUSION

The Freestyle stentless xenograft is a viable alternative for treatment of valve/root and prosthetic endocarditis. In our experience, it showed good postoperative performance with low rate of reinfection while having an acceptable operative risk-profile for this high-risk cohort.

A standardized approach to treat complex aortic valve endocarditis: a case series

Background

Surgical treatment of complicated aortic valve endocarditis often is challenging, even for experienced surgeons. We aim at demonstrating a standardized surgical approach by stentless bioprostheses for the treatment of aortic valve endocarditis complicated by paravalvular abscess formation.

Methods

Sixteen patients presenting with aortic valve endocarditis (4 native and 12 prosthetic valves) and paravalvular abscess formation at various localizations and to different extents were treated by a standardized approach using stentless bioprostheses. The procedure consisted of thorough debridement, root replacement with reimplantation of the coronary arteries and correction of accompanying pathologies (aortoventricular and aortomitral dehiscence, septum derangements, Gerbode defect, total atrioventricular conduction block, mitral and tricuspid valve involvement).

Results

All highly complex patients included (14 males and 2 females; median age 63 years [range 31–77]) could be successfully treated with stentless bioprostheses as aortic root replacement. Radical surgical debridement of infected tissue with anatomical recontruction was feasible. Although predicted operative mortality was high (median logarithmic EuroSCORE I of 40.7 [range 12.8–68.3]), in-hospital and 30-day mortality rates were favorable (18.8 and 12.5% respectively).

Conclusions

Repair of active aortic valve endocarditis complicated by paravalvular abscess formation and destruction of the left ventricular outflow tract with stentless bioprosthesis is a valuable option for both native and prosthetic valves. It presents a standardized approach with a high success rate for complete debridement, is readily available, and yields comparable clinical outcomes to the historical gold standard, repair by homografts. Additionally, use of one type of prosthesis reduces logistical issues and purchasing costs.

Stentless vs. stented bioprosthesis for aortic valve replacement: A case matched comparison of long-term follow-up and subgroup analysis of patients with native valve endocarditis

Background

Current retrospective evidence suggests similar clinical and superior hemodynamic outcomes of the Sorin Freedom Solo stentless aortic valve (SFS) (LivaNova PLC, London, UK) compared to the Carpentier Edwards Perimount stented aortic valve (CEP) (Edwards Lifesciences Inc., Irvine, California, USA). To date, no reports exist describing case-matched long-term outcomes and analysis for treatment of native valve endocarditis (NVE).

Methods

From 2004 through 2014, 77 consecutive patients (study group, 59.7% male, 68.9 ± 12.5 years, logEuroSCORE II 7.6 ± 12.3%) received surgical aortic valve replacement (SAVR) with the SFS. A control group of patients after SAVR with the CEP was retrieved from our database and matched to the study group regarding 15 parameters including preoperative endocarditis. Acute perioperative outcomes and follow-up data (mean follow-up time 48.7±29.8 months, 95% complete) were retrospectively analyzed.

Results

No differences in early mortality occurred during 30-day follow up (3/77; 3.9% vs. 4/77; 5.2%; p = 0.699). Echocardiographic findings revealed lower postprocedural transvalvular pressure gradients (max. 17.0 ± 8.2 vs. 24.5 ± 9.2 mmHg, p< 0.001/ mean pressure of 8.4 ± 4.1 vs. 13.1 ± 5.9 mmHg, p< 0.001) in the SFS group. Structural valve degeneration (SVD) (5.2% vs. 0%; p = 0.04) and valve explantation due to SVD or prosthetic valve endocarditis (PVE) (9.1% vs. 1.3%; p = 0.04) was more frequent in the SFS group. All-cause mortality during follow-up was 20.8% vs. 14.3% (p = 0.397). When patients were divided into subgroups of NVE and respective utilized bioprosthesis, the SFS presented impaired outcomes regarding mortality in NVE cases (p = 0.031).

Conclusions

The hemodynamic superiority of the SFS was confirmed in this comparison. However, clinical outcomes in terms of SVD and PVE rates, as well as survival after NVE, were inferior in this study. Therefore, we are reluctant to recommend utilization of the SFS for treatment of NVE.

Complicated infective aortic endocarditis: comparison of different surgical strategies

OBJECTIVES

The choice of substitute during aortic valve replacement for infective endocarditis (IE) is still widely debated. We retrospectively reviewed all patients operated for aortic IE and compared groups according to the complexity of IE and substitutes implanted.

METHODS

From 2000 to 2015, 187 patients were treated using stentless bioprostheses (SBP) as root replacement (n = 30), mechanical prostheses (MP, n = 45) or stented bioprostheses (SP, n = 112) (mean follow-up 4.6 years, survival data 100% complete).

RESULTS

MP patients were younger (42.5 ± 10.7 vs 57.2 ± 16.9 years [SBP], 59.1 ± 14.1 years [SP], P < 0.01), but rates of intravenous drug use and chronic dialysis were not different. SBP patients more often had root involvement (83.3% vs 33.3% [MP], 25.9% [SP], P < 0.01) and prosthetic valve endocarditis (53.3% vs 6.7% [MP], 12.5% [SP], P < 0.01). In-hospital complications and length of stay were not different. Thirty-day mortality was 13.3% [SBP], 6.7% [MP] and 12.5% [SP] (P = 0.53). Five-year survival tended to be superior in SBP (83.3% vs 77.6% [MP], 67.1% [SP], P = 0.09). In patients with complicated IE (root involvement or prosthetic valve endocarditis, n = 77), SBP had superior long-term survival (86.9% vs 81.3% [MP], 57.2% [SP], PSBP/MP  = 0.07, PSBP/SP = 0.05). No early reinfection (<90 days) occurred in SBP vs 4.4% [MP] and 7.1% [SP] (P = 0.29). Reoperation for late reinfection occurred in 6.7% [SBP] vs 11.1% [MP] and 12.5% [SP] (P = 0.65). Prosthesis failure occurred in 3.3% [SBP] and 1.8% [SP] (P = 0.52).

CONCLUSIONS

Use of SBP provides favourable outcomes in patients with IE with low rates of reinfection and valve deterioration. It seems to be an optimal device in patients with complex IE.

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.

Stentless bioprostheses: a versatile and durable solution in extensive aortic valve endocarditis

OBJECTIVES

Infective endocarditis of the aortic valve with local aortic root destruction requires radical resection of infected tissues and subsequent reconstruction of periannular structures and the left ventricular outflow tract (LVOT). Homografts or stentless bioprostheses are recommended for use in this specific patient group. The Freestyle stentless bioprosthesis is a porcine aortic root prosthesis, which approaches the surgical versatility of the homograft, but has the advantage of ready availability and uniform quality. We assessed clinical and echocardiographic outcome following the use of this prosthesis in extensive aortic valve endocarditis.

METHODS

Between June 2000 and December 2014, 55 Freestyle prostheses were implanted for aortic valve endocarditis involving the root in 54 patients (74% male). The mean age at operation was 61 ± 13 years. The mean EuroSCORE II was 20.1 ± 13.5. Twenty-nine (54%) patients had prosthetic valve endocarditis. The median follow-up time after surgery was 3.5 years, ranging from 0 to 15 years.

RESULTS

Early and late mortality were 11% (6 patients) and 14% (7 patients), respectively. Estimated overall survival at 1 and 5 years was 83 and 70%, respectively. There was no survival difference between patients with native or prosthetic valve endocarditis. One patient underwent reoperation for recurrent endocarditis 2.3 years after the initial procedure. No other prosthesis failure occurred. At a median follow-up of 3.3 years, mean gradient over the prosthesis was 4.3 ± 2.3 mmHg. No patient had more than mild aortic regurgitation.

CONCLUSIONS

The Freestyle stentless bioprosthesis is a valuable option to reconstruct the LVOT after debridement in extensive aortic valve endocarditis. It is readily available with a versatility and clinical outcome comparable with that of homografts. Although early mortality remains considerable in this high-risk group of patients, late survival is good with low rates of recurrence of endocarditis, immediate local control and good haemodynamic performance on echocardiography.

Surgical management of destructive aortic endocarditis: left ventricular outflow reconstruction with the Sorin Pericarbon Freedom stentless bioprosthesis†

OBJECTIVES

The treatment of complicated aortic endocarditis with periannular abscesses and root disarrangement is a surgical challenge, and includes left ventricular outflow tract (LVOT) reconstruction with the patch technique or homograft implantation. The results of a simplified technique to reconstruct the LVOT in destructive endocarditis of either the aortic native valve or valve prosthesis with the Sorin Pericarbon Freedom stentless valve are reported.

METHODS

Since August 2007, 40 patients with destructive endocarditis (mean age: 69 ± 12, 75% males, European System for Cardiac Operative Risk Evaluation II (EuroSCORE II): 19 ± 13, New York Heart Association (NYHA) class: ≥3 in all cases) have undergone LVOT reconstruction with a Sorin Pericarbon Freedom stentless bioprosthesis. Seven patients (17.5%) were in septic or cardiogenic shock preoperatively, and 18 patients (45%) suffered from moderate or severe aortic regurgitation. Eleven patients (27.5%) experienced preoperative systemic embolizations. Thirty-six cases (90%) were valve redos and 9 patients (22.5%) had concomitant procedures. The mean follow-up was 26 ± 25 months.

RESULTS

One patient (2.5%) died early (<30 days) and another 3 patients never discharged died due to multiorgan failure and septic shock. Actuarial survival rate was 85 ± 6% at 1 year, and 76 ± 8% at 3 and 5 years, respectively. Twelve patients (30%) required pacemaker implantation because of atrioventricular block and 20 patients (50%) developed or showed a progression of renal failure. One patient (2.5%) had an endocarditis relapse, and 1 (2.5%) showed a mild paraprosthetic aortic leak. No patient needed reoperation. At the last echocardiographic evaluation, mean gradient, peak gradient and left ventricular ejection fraction were 7.9 ± 5.0 mmHg, 15.1 ± 7.2 mmHg and 63.3 ± 9.3%, respectively.

CONCLUSIONS

The Sorin Pericarbon Freedom stentless prosthesis, with the modified technique herein described, seems to be a good option in most of cases of destructive aortic valve endocarditis. It is promptly available in different sizes, easy to implant and, due to its pericardial inflow skirt, ideal for extensive reconstruction of the LVOT with good haemodynamic performance and low risk of relapse.

Freestyle root replacement for complex destructive aortic valve endocarditis

OBJECTIVES

In destructive aortic valve endocarditis with abscess formation in the root, homografts are used more often than xenografts. Because we had reliable perioperative results with Freestyle (Medtronic Inc, Minneapolis, Minn) xenograft root replacement in these complex patients, we analyzed the long-term outcome in this high-risk indication.

METHODS

Of 126 consecutive patients with aortic valve endocarditis treated by surgery from 1997 to 2012, 32 (25.4%) received a Freestyle aortic root replacement for severe, destructive valve endocarditis and were studied retrospectively with approval of the local ethical committee. Perioperative complications, recurrence of endocarditis, and long-term morbidity and mortality were analyzed. The follow-up period was 3 months to 11.5 years.

RESULTS

Indication for surgery was native (n = 9) and prosthetic valve endocarditis (n = 23). In 18 patients, concomitant procedures were performed: coronary bypass (n = 9), additional valve surgery (n = 6), and ascending aortic surgery (n = 7). Thirty-day mortality was 19.4% (n = 6). There were no instances of technical failure requiring modification of the surgical strategy or reoperation for anastomotic bleeding. Actuarial survival at 5 and 10 years was 61.9% and 54.2%, respectively. Freedom from death, reoperation for prostheses dysfunction, and recurrence of endocarditis as the composite end point at 5 and 10 years was 56.3% and 53.1%, respectively.

CONCLUSIONS

The Freestyle root was used successfully with no technical complications in all patients with most severe destructive aortic root endocarditis. In view of this complex patient population, short- and long-term results make this conduit a reliable choice for treatment of this condition.