Stentless Aortic Valves are Hemodynamically Superior to Stented Valves During Mid-Term Follow-Up: A Large Retrospective Study

Long-Term Results (up to 20 Years) of 19 mm or Smaller Prostheses in the Aortic Position. Does Size Matter? A Propensity-Matched Survival Analysis

Background: The long-term performance of prostheses in the small aortic root is still unclear. Methods: Patients who received a 21 mm or smaller aortic valve between 2000–2018 were retrospectively analyzed. Propensity matching was used in order to account for baseline differences in 19 mm vs. 21 mm valve subgroups. Results: Survival at 10 years was 55.87 ± 5.54% for 19 mm valves vs. 57.17 ± 2.82% for 21 mm ones in the original cohort (p = 0.37), and 58.69 ± 5.61% in 19 mm valve recipients vs. 53.60 ± 5.66% for 21 mm valve subgroups in the matched cohort (p = 0.55). Smaller valves exhibited significantly more patient–prothesis mismatch (PPM) than larger ones (87.30% vs. 57.94%, p < 0.01). All-cause mortality was affected by PPM at 10 years (52.66 ± 3.28% vs. 64.38 ± 3.87%, p = 0.04) in the unmatched population. This difference disappeared, however, after matching: survival at 10 years was 51.82 ± 5.26% in patients with PPM and 63.12 ± 6.43% in patients without PPM. (p = 0.14) Conclusions: There is no survival penalty in using 19 mm prostheses in the small aortic root in the current era. Although PPM is more prevalent in smaller sized valve recipients, this does not translate into reduced survival at 10 years of follow-up.

Structural valve deterioration and mode of failure of stentless bioprosthetic valves

BACKGROUND

Aortic stentless bioprosthetic valve (SLBPV), either porcine or pericardial, minimizes transvalvular gradient and favors regression of left ventricular hypertrophy. The drawback consists of longer time for suturing. While structural valve deterioration (SVD) in stented porcine and pericardial BPVs has been extensively investigated, less information is available on SLBPVs.

MATERIAL AND METHODS

We studied 82 SLBPVs explants, either porcine (Toronto SPV, [St. Jude Medical, MN, USA], CryolifeO'Brien Model 300 and CryoLife-O'Brien [Cryolife International, GA, USA], BioCor PVS [St. Jude Medical, MN, USA] Prima and Prima Plus [Edwards Lifesciences Corp. One Edwards Way, CA, formerly Baxter Inc, CA, USA]) or pericardial ([Pericarbon Freedom and Freedom Solo [Sorin-Biomedica, S.p.A., Saluggia, Italy]).

RESULTS

By excluding cases with leak and endocarditis, we focused the investigation on 46 SLBPVs, which failed because of SVD. Gender was male in 29 (63%). Mean age of patients at time of implant was 59.8 years. Postoperative time of SVD was 115.0 months for porcine and 79.0 months for pericardial SLBPVs. Dysfunction requiring reoperation was mainly incompetence for porcine and stenosis for pericardial SLBPVs. Even pinpoint mineralization at the commissures resulted in sudden cusp tearing and incompetence. Cuspal atheromasia accounted for cusp tearing even in the absence of calcification. Mineralization showed progression with time in pericardial but not in porcine SLBPVs.

CONCLUSIONS

Tissue mineralization remains the nightmare also of SLBPVs, with the peculiar features of pinpoint calcific deposits at commissures, tearing and abrupt incompetence in porcine SLBPVs and of massive cuspal mineralization and stenosis in pericardial SLBPVs.

Intermediate-Term Outcomes After Aortic Valve Replacement With the Medtronic 3F Stentless Prosthesis

BACKGROUND

This study evaluated the early and intermediate-term clinical and hemodynamic results after implant of the Medtronic 3F (Minneapolis, MN) stentless aortic valve.

METHODS

Between March 2007 and August 2015, 226 consecutive patients affected by aortic valve disease received a 3F valve at our unit by a single surgeon. The valve in 30 patients was included in a tubular prosthesis for a Bentall procedure. Size ranged between 21 and 29, age at operation was 74.17 ± 8.58 years, mean logistic European System for Cardiac Operative Risk Evaluation was 9.73 ± 6.00, and 51.3% of patients received a concomitant procedure. For isolated valve replacement, mean extracorporeal circulation time was 92 ± 17 minutes, and cross-clamp time was 73 ± 11 minutes. Follow-up was 100% complete and was a mean of 63 ± 2.4 months (range, 6-138 months). Primary end points were early and late mortality, freedom from endocarditis, freedom from structural valve deterioration, and freedom from valve-related reoperation.

RESULTS

Early mortality after isolated aortic valve replacement was 1.7%. Of the 59 (25.3%) late overall deaths, 15 (6.6%) were cardiac-related, and survival rate was 93% at 10 years. At follow-up, 97% of patients were in New York Heart Association class I or II. Actuarial freedom from reoperation due to structural deterioration was 100% at 5 years and 96% at 10 years. Freedom from endocarditis at 10 years was 97%. Mean aortic pressure gradient measured by echocardiography was 11.5 mm Hg at hospital discharge and 10.4 mm Hg at the last follow-up.

CONCLUSIONS

The 3F valve is a user-friendly third-generation stentless aortic prosthesis with proven durability and remarkable hemodynamic performance preserved over time. The 3F is particularly useful in cases of expected patient/prosthesis mismatch.

Long-term clinical outcomes of the Toronto stentless porcine valve: 15-year results from dual centers

BACKGROUND AND AIM OF THE STUDY

The purpose of this study is to examine the long-term durability of the Toronto stentless porcine valve (SPV) in the aortic position (St Jude Medical, Minneapolis, MN).

METHODS

We assessed the long-term clinical outcomes of 515 patients with aortic valve replacement (AVR) with the Toronto SPV from 1987 to 2001 at two centers, excluding early (<30 days) death. Median follow-up was 11.5 years (maximum 19.0 years).

RESULTS

Average age was 64.2 ± 10.8 years, and females were 34% (173/515). The incidence of prosthesis-patient mismatch was low, 10.9%. Overall survival was 90.7 ± 1.3%, 75.4 ± 2.0%, and 56.8 ± 3.2% at 5, 10, and 15 years, respectively after surgery. Over the follow-up duration, 116 patients (23%) underwent repeated AVR: 90 for structural valve deterioration (SVD), 12 for endocarditis, 10 nonstructural valve dysfunction (10 aortic regurgitation due to aorta dilatation), and four for other reasons. The cumulative incidence of repeated AVR with death as a competing risk was 1.4% (95% confidence interval [CI], 0.6-2.7), 11.1% (95% CI, 8.4-14.2), and 34.4% (95% CI, 28.8-40.2) at 5, 10, and 15 years, respectively. Reoperative mortality was 5.2% (6/116). In SVD, the regurgitation type was dominant (82%).

CONCLUSIONS

The Toronto SPV is associated with excellent survival and durability during the first decade of follow-up. However, regurgitation type of SVD increases from 10 years after operation with acceptable reoperative mortality. These findings may assist with prosthesis selection and reintervention strategy for failing stentless bioprosthesis.

Aortic root replacement to treat type A aortic dissection: A comparison of midterm outcomes between composite valve grafts and porcine aortic roots

BACKGROUND

Porcine aortic roots (PAR) have been reported in the literature with acceptable short- and long-term outcomes for the treatment of aortic root aneurysms. However, their efficacy in type A aortic dissection (TAAD) is yet to be defined.

METHODS

Using data from a locally collated aortic dissection registry, we compared the outcomes in patients undergoing aortic root replacement for TAAD using either of two surgical options: (a) PAR or (b) composite valve grafts (CVG). A retrospective analysis was conducted for all procedures in the period from 2005 to 2018.

RESULTS

A total of 252 patients underwent procedures for TAAD in the time period. Sixty-five patients had aortic root replacements (PAR n = 30, CVG n = 35). Between-group comparisons identified a younger CVG group (50.5 vs 64.5, P < .05) although all other covariates were comparable. Operative parameters were comparable between the two groups. The use of PAR did not significantly impact operative mortality (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.22-3.61; P = .992), stroke (OR, 2.91, 0.25-34.09, P = .395), reoperation (OR, 0.91; 95% CI, 0.22-3.62; P = .882) or length of stay (coeff 2.33, -8.23 to 12.90; P = .659) compared to CVG. Five-year survival was similar between both groups (PAR 59% vs CVG 69%; P = .153) and reoperation was negligible. Echocardiography revealed significantly lower aortic valve gradients in the PAR group (8.69 vs 15.45mm Hg; P < .0001), and smaller left ventricular dimensions both at 6-week and 1-year follow-up (P < .05).

CONCLUSIONS

This study highlights the comparable short- and midterm outcomes of PAR in cases of TAAD, in comparison to established therapy.

Stentless Pericarbon Freedom Versus Stented Perimount Aortic Bioprosthesis: Propensity-Matched Long-Term Follow-Up

OBJECTIVE

Stentless aortic valves have shown superior hemodynamic performance and faster left ventricular mass regression compared to stented bioprostheses. Yet, controversies exist concerning the durability of stentless valves. This case-matched study compared short- and long-term clinical outcomes of stentless LivaNova-Sorin Pericarbon Freedom™ (SPF) and stented Carpentier-Edwards Perimount (CEP) aortic prostheses.

METHODS

From 2003 through 2006, 134 consecutive patients received aortic valve replacement with SPF at our institution. This cohort was matched, according to 20 preoperative clinical parameters, with a control group of 390 patients who received CEP prosthesis during the same time. The resulting 55 + 55 matched patients were analyzed for perioperative results and long-term clinical outcomes.

RESULTS

Early mortality was 0% for both groups. Lower transvalvular gradients were found in the SPF group (10.6 ± 2.9 versus 15.7 ± 3.1 mmHg, P < 0.001). Overall late mortality (mean follow-up: 10.03 years) was similar for both groups (50.1% versus 42.8%, P = 0.96). Freedom from structural valve degeneration (SVD) at 13 years was similar for both groups (SPF = 92.3%, CEP = 73.9%, P = 0.06). Freedom from aortic valve reinterventions did not differ (SPF = 92.3%, CEP = 93.5%, P = 0.55). Gradients at 13-year follow-up remained significantly lower in SPF group (10.0 ± 4.5 versus 16.2 ± 9.5 mmHg, P < 0.001). Incidence of acute bacterial endocarditis (ABE) and major adverse cardiovascular and cerebrovascular events (MACCE) was similar.

CONCLUSIONS

SPF and CEP demonstrated comparable long-term outcomes related to late mortality, SVD, aortic valve reinterventions, and incidence of ABE and MACCE. Superior hemodynamic performance of SPF over time can make this valve a suitable choice in patients with small aortic root and large body surface area.

Transcatheter aortic valve replacement in failed surgical valves

Aortic valve-in-valve is a less invasive alternative to surgical redo in the treatment of failed bioprosthetic valves. While only inoperable patients underwent the procedure before, operators currently offer it to those at lower risk and worldwide experience is in the thousands. Early mortality has diminished in recent analyses and improvements in symptoms and quality of life have been documented. Main considerations with aortic valve-in-valve include elevated postprocedural gradients, coronary obstruction and leaflet thrombosis. Risk factors for each of these adverse events have been described at length. Aortic valve-in-valve offers a safe and effective option in the management of failed bioprosthetic valves.

Complementary Role of the Computed Biomodelling through Finite Element Analysis and Computed Tomography for Diagnosis of Transcatheter Heart Valve Thrombosis

Introduction

The TAVR procedure is associated with a substantial risk of thrombosis. Current guidelines recommend catheter-based aortic valve implantation for prohibitive-high-risk patients with severe aortic valve stenosis but acknowledge that the aetiology and mechanism of thrombosis are unclear.

Methods

From 2015 to 2018, 607 patients with severe aortic valve stenosis underwent either self-expandable or balloon-expandable catheter-based aortic valve implantation at our institute. A complementary study was designed to support computed tomography as a predictor of complications using an advanced biomodelling process through finite element analysis (FEA). The primary evaluation of study was the thrombosis of the valve at 12 months.

Results

At 12 months, 546 patients had normal valvular function. 61 patients had THVT while 6 showed thrombosis and dislodgement with deterioration to NYHA Class IV requiring rehospitalization. The FEA biomodelling revealed a strong link between solid uncrushed calcifications, delayed dislodgement of TAVR and late thrombosis. We observed an interesting phenomenon of fibrosis/calcification originating at the level of the misplaced valve, which was the primary cause of coronary obstruction.

Conclusion

The use of cardiac CT and predictive biomodelling should be integrated into routine practice for the selection of TAVR candidates and as a predictor of negative outcomes given the lack of accurate investigations available. This would assist in effective decision-making and diagnosis especially in a high-risk cohort of patients.

Morphometrical and biomechanical analyses of a stentless bioprosthetic valve: an implication to avoid potential primary tissue failure

OBJECTIVES

Stentless bioprosthetic valves provide hemodynamic advantages over stented valves as well as excellent durability. However, some primary tissue failures in bioprostheses have been reported. This study was conducted to evaluate the morphometrical and biomechanical properties of the stentless Medtronic Freestyle™ aortic root bioprosthesis, to identify any arising problem areas, and to speculate on a potential solution.

METHODS

The three-dimensional heterogeneity of the stentless bioprosthesis wall was investigated using computed tomography. The ascending aorta and the right, left, and non-coronary sinuses of Valsalva were resected and examined by an indentation test to evaluate their biomechanical properties.

RESULTS

The non-coronary sinus of Valsalva was significantly thinner than the right sinus of Valsalva (p < 0.01). Young's modulus, calculated as an indicator of elasticity, was significantly greater at the non-coronary sinus of Valsalva (430.7 ± 374.2 kPa) than at either the left (190.6 ± 70.6 kPa, p < 0.01) or right sinuses of Valsalva (240.0 ± 56.5 kPa, p < 0.05).

CONCLUSIONS

Based on the morphometrical and biomechanical analyses of the stentless bioprosthesis, we demonstrated that there are differences in wall thickness and elasticity between each sinus of Valsalva. These differences suggest that the non-coronary sinus of Valsalva is the most vulnerable and at greater risk of tissue failure. The exclusion of the non-coronary sinus of Valsalva may be beneficial to mitigate the long-term risks of tissue failure in the stentless bioprosthesis.

Surgical Enlargement of the Aortic Root Does Not Increase the Operative Risk of Aortic Valve Replacement

Background:

Surgical aortic root enlargement (ARE) during aortic valve replacement (AVR) allows for larger prosthesis implantation and may be an important adjunct to surgical AVR in the transcatheter valve-in-valve era. The incremental operative risk of adding ARE to AVR has not been established. We aimed to evaluate the early outcomes of patients undergoing AVR with or without ARE.

Methods:

From January 1990 to August 2014, 7039 patients underwent AVR (AVR+ARE, n=1854; AVR, n=5185) at a single institution. Patients with aortic dissection and active endocarditis were excluded. Mean age was 65±14 years and 63% were male. Logistic regression and propensity score matching were used to adjust for unbalanced variables in group comparisons.

Results:

Patients undergoing AVR+ARE were more likely to be female (46% versus 34%, P <0.001) and had higher rates of previous cardiac surgery (18% versus 12%, P <0.001), chronic obstructive pulmonary disease (5% versus 3%, P =0.004), urgent/emergent status (6% versus 4%, P =0.01), and worse New York Heart Association status ( P <0.001). Most patients received bioprosthetic valves (AVR+ARE: 73.4% versus AVR: 73.3%, P =0.98) and also underwent concomitant cardiac procedures (AVR+ARE: 68% versus AVR: 67%, P =0.31). Mean prosthesis size implanted was slightly smaller in patients requiring AVR+ARE versus AVR (23.4±2.1 versus 24.1±2.3, P <0.001). In-hospital mortality was higher after AVR+ARE (4.3% versus 3.0%, P =0.008), although when the cohort was restricted to patients undergoing isolated aortic valve replacement with or without root enlargement, mortality was not statistically different (AVR+ARE: 1.7% versus AVR: 1.1%, P =0.29). After adjustment for baseline characteristics, AVR+ARE was not associated with an increased risk of in-hospital mortality when compared with AVR (odds ratio, 1.03; 95% confidence interval, 0.75–1.41; P =0.85). Furthermore, AVR+ARE was not associated with an increased risk of postoperative adverse events. Results were similar if propensity matching was used instead of multivariable adjustments for baseline characteristics.

Conclusions:

In the largest analysis to date, ARE was not associated with increased risk of mortality or adverse events. Surgical ARE is a safe adjunct to AVR in the modern era.

Sutureless versus Conventional Aortic Valve Replacement: Outcomes in 70 High-Risk Patients Undergoing Concomitant Cardiac Procedures

In elderly, high-risk surgical patients, sutureless aortic valve replacement (AVR) can often be an alternative to conventional AVR; shorter aortic cross-clamp and cardiopulmonary bypass times are the chief advantages. We compared the outcomes of sutureless AVR with those of conventional AVR in 70 elderly patients who underwent concomitant cardiac surgical procedures. We retrospectively analyzed the cases of 42 men and 28 women (mean age, 70.4 ± 10.3 yr; range, 34-93 yr) who underwent cardiac operations plus AVR with either a sutureless valve (group 1, n=38) or a conventional bioprosthetic or mechanical valve (group 2, n=32). Baseline patient characteristics were similar except for worse New York Heart Association functional status and the prevalence of diabetes mellitus in group 1. In group 1, the operative, cross-clamp, and cardiopulmonary bypass times were shorter (all P=0.001), postoperative drainage amounts were lower (P=0.009), hospital stays were shorter (P=0.004), and less red blood cell transfusion was needed (P=0.037). Echocardiograms before patients' discharge from the hospital showed lower peak and mean aortic gradients in group 1 (mean transvalvular gradient, 8.4 ± 2.8 vs 12.2 ± 5.2 mmHg; P=0.012). We found that elderly, high-risk patients who underwent multiple cardiac surgical procedures and sutureless AVR had better hemodynamic outcomes and shorter ischemic times than did patients who underwent conventional AVR.

Hemodynamics of Pericardial Aortic Valves: Contemporary Stented versus Stentless Valves in a Matched Comparison

PURPOSE

Hemodynamic performance of aortic valve bioprostheses is essential for reliable function and durability. So far, the supra-annularly implanted stentless Sorin Freedom Solo (SFS) demonstrated unsurpassed hemodynamic properties. As contemporary stented and externally mounted pericardial bioprostheses, like the Labcor Dokimos Plus (LDP), also improve hemodynamic performance, these types of valves were compared in this study.

METHODS

A total of 218 patients, who underwent aortic valve replacement with the LDP or the SFS, were matched retrospectively 1:1 on variables affecting hemodynamic measurements: implanted valve size, age, sex, and body surface area (BSA). With matching tolerance for valve size and gender of 0%, for age and BSA of 5%, 57 patient-pairs were yielded. Operative data, clinical, and hemodynamic outcome were analyzed.

RESULTS

Except for slightly higher left ventricular function and lower procedural times in the SFS group, preoperative, operative, and postoperative characteristics of patient-pairs did not differ significantly. Mean pressure gradients, effective orifice areas (EOAs), and indexed EOAs were comparable. Corresponding to valve sizes of 21, 23, 25, and 27 mm, the indexed EOAs of the LDP and SFS prostheses were 1.08 ± 0.33, 0.92 ± 0.19, 0.93 ± 0.24, 0.99 ± 0.13 cm²/m² and 0.81 ± 0.13, 0.92 ± 0.28, 0.95 ± 0.20, 1.04 ± 0.27 cm²/m², respectively.

CONCLUSION

Contemporary stented and stentless pericardial bioprostheses showed excellent hemodynamic properties without significant differences in EOAs and indexed EOAs.

A propensity matched analysis of outcomes and long term survival in stented versus stentless valves

BACKGROUND

To compare the perioperative and long term survival after aortic valve replacement using stentless versus stented valves in a large cohort of patients grouped using propensity score matching.

METHODS

From 1991 to 2012, 4,563 patients underwent aortic valve replacement with stentless and stented valves at our institution. Propensity score matching identified 444 pairs using 13 independent variables: incidence of operation, smoking status, renal failure, hypertension, diabetes, peripheral vascular disease, cerebrovascular disease, chronic lung disease, ejection fraction, gender, age, valve status, and use of coronary artery bypass graft. Data were collected from our Society of Thoracic Surgeons database and the Social Security Death Index. Groups were compared using univariate and Kaplan-Meier analysis.

RESULTS

The two groups demonstrated no significant differences for the 13 matching variables and the majority of 30-day outcomes (p > 0.05). The stented valve group showed a higher incidence of postoperative bleeding (3.6% vs 1.1%, p = 0.015), but a lower incidence of stroke (0.9% vs. 2.9%, p = 0.028). One, five, and 10-year survival was 95.0, 80.7, and 52.8% for stented and 93.2, 80.5, and 51.3% for stentless valves. Overall survival did not differ significantly between the two groups (p = 0.641).

CONCLUSIONS

Stentless and stented valves had identical 30-day outcomes except for a higher postoperative incidence of bleeding and a lower incidence of stroke in the stented group. There was no significant difference in long term survival between valve types. Both valves may be used for aortic valve replacement with low morbidity and excellent long term survival.

Chest Blunt Trauma: An Uncommon Cause of Aortic Stentless Bioprosthesis Dysfunction

Acute leaflet rupture occurred in a Freedom Solo (Sorin Group, Milan, Italy) pericardial stentless aortic bioprosthesis after chest blunt trauma 8 years after valve replacement. Intraoperative findings revealed an acute tear of the right cusp at the level of the structural suture line. Pericardial leaflets were not degenerated at histologic analysis. Reoperation was easy, with simple removal of the prosthetic cusps, and a sutureless Perceval (Sorin Group) bioprosthesis was successfully implanted. This is the first reported case of an acute rupture of a stentless aortic bioprosthesis after a chest blunt trauma and the first histologic analysis of an 8-year-old Freedom Solo.

Assessment of Hemodynamic Conditions in the Aorta Following Root Replacement with Composite Valve-Conduit Graft

This paper presents the analysis of detailed hemodynamics in the aortas of four patients following replacement with a composite bio-prosthetic valve-conduit. Magnetic resonance image-based computational models were set up for each patient with boundary conditions comprising subject-specific three-dimensional inflow velocity profiles at the aortic root and central pressure waveform at the model outlet. Two normal subjects were also included for comparison. The purpose of the study was to investigate the effects of the valve-conduit on flow in the proximal and distal aorta. The results suggested that following the composite valve-conduit implantation, the vortical flow structure and hemodynamic parameters in the aorta were altered, with slightly reduced helical flow index, elevated wall shear stress and higher non-uniformity in wall shear compared to normal aortas. Inter-individual analysis revealed different hemodynamic conditions among the patients depending on the conduit configuration in the ascending aorta, which is a key factor in determining post-operative aortic flow. Introducing a natural curvature in the conduit to create a smooth transition between the conduit and native aorta may help prevent the occurrence of retrograde and recirculating flow in the aortic arch, which is particularly important when a large portion or the entire ascending aorta needs to be replaced.

Systemic Semilunar Valve Replacement in Pediatric Patients Using a Porcine, Full-Root Bioprosthesis

BACKGROUND

Management of systemic semilunar valve disease in growing, young patients is challenging. When replacement is necessary, use of a pulmonary autograft is sometimes not possible for anatomic, pathologic, or technical reasons or due to parental or patient preference. We employed a stentless, porcine, full-root bioprosthesis in this setting and report our outcomes.

METHODS

Over 9 years (2005 to 2013), 24 patients of mean age 13.1 years (range, 3 months to 20.3 years) underwent operation for mixed stenosis and insufficiency in 16 of 24 (67%), pure insufficiency in 7 of 24 (29%), and pure stenosis in 1 of 24 (4%). Twenty patients had previous interventions of repair or replacement, valvuloplasty, or multiple operations. Survival, follow-up echocardiographic findings, and outcomes were documented. All patients were maintained on daily aspirin.

RESULTS

There were no hospital deaths and no early or late deaths over a mean follow-up for 23 patients of 46.1 months (range, 14 months to 9.2 years). One patient moved abroad and was lost to follow-up. Echocardiographic follow-up (mean 34.0 months) demonstrated that no patient developed more than mild insufficiency or moderate stenosis. In total, 20 of 24 (83%) showed no insufficiency and 11 of 24 patients (46%) showed no stenosis. Near or complete normalization of left ventricular mass and dimension was demonstrated. There were no explants and no thromboembolic or bleeding events.

CONCLUSIONS

When use of a pulmonary autograft is not an option, the porcine full-root bioprosthesis appears favorable for systemic semilunar valve replacement in the pediatric and young adult population. Of note, when prosthetic degeneration does occur, stenosis predominates rather than insufficiency. Longer term studies are warranted.

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.

EFFICACY OF CARPENTIER-EDWARDS PERICARDIAL PROSTHESES: A SYSTEMATIC REVIEW AND META-ANALYSIS

Objectives: The Carpentier-Edwards pericardial (CEP) prostheses are the type of bioprostheses most used worldwide. Although they were designed to minimize the rate of valve deterioration and reoperation, their clinical superiority over other prostheses models still lacks confirmation. The objective of this study was to evaluate its effectiveness.

Methods: We performed a systematic review and meta-analysis in the PubMed, Embase, Cochrane, and Lilacs databases. Operative mortality, overall mortality and reoperation rates after heart valve surgery were compared between the use of CEP and other cardiac prostheses. Two independent reviewers screened studies for inclusion and extracted the data. Disagreements were resolved by consensus. The GRADE criterion was used to assess the evidence quality.

Results: A total of twenty-eight studies were selected, including 19,615 individuals. The studies presented a high heterogeneity and low quality of evidence what limited the reliability of the results. The pooled data from the selected studies did not demonstrate significant differences between CEP and porcine, pericardial or stentless prostheses regarding operative mortality, overall mortality and reoperation rates. However, the pooled data from 3 observational trials pointed out a higher risk for reoperation after valve replacement using CEP prostheses against mechanical prostheses (OR 4.92 [95 percent confidence interval 2.43–9.96]).

Conclusions: The current data present in the literature still does not support a clinical advantage for the use of CEP prostheses over other bioprostheses. The quality of the studies in the literature is limited and further studies are needed to address if CEP prostheses will have a clinical advantage over other prostheses.

Full-root aortic valve replacement with stentless xenograft achieves superior regression of left ventricular hypertrophy compared to pericardial stented aortic valves

BACKGROUND

Full-root aortic valve replacement with stentless xenografts has potentially superior hemodynamic performance compared to stented valves. However, a number of cardiac surgeons are reluctant to transform a classical stented aortic valve replacement into a technically more demanding full-root stentless aortic valve replacement. Here we describe our technique of full-root stentless aortic xenograft implantation and compare the early clinical and midterm hemodynamic outcomes to those after aortic valve replacement with stented valves.

METHODS

We retrospectively compared the pre-operative characteristics of 180 consecutive patients who underwent full-root replacement with stentless aortic xenografts with those of 80 patients undergoing aortic valve replacement with stented valves. In subgroups presenting with aortic stenosis, we further analyzed the intra-operative data, early postoperative outcomes and mid-term regression of left ventricular mass index.

RESULTS

Patients in the stentless group were younger (62.6 ± 13 vs. 70.3 ± 11.8 years, p < 0.0001) but had a higher Euroscore (9.14 ± 3.39 vs.6.83 ± 2.54, p < 0.0001) than those in the stented group. In the subgroups operated for aortic stenosis, the ischemic (84.3 ± 9.8 vs. 62.3 ± 9.4 min, p < 0.0001) and operative times (246.3 ± 53.6 vs. 191.7 ± 53.2 min, p < 0.0001) were longer for stentless versus stented valve implantation. Nevertheless, early mortality (0% vs. 3%, p < 0.25), re-exploration for bleeding (0% vs. 3%, p < 0.25) and stroke (1.8% vs. 3%, p < 0.77) did not differ between stentless and stented groups. One year after the operation, the mean transvalvular gradient was lower in the stentless versus stented group (5.8 ± 2.9 vs. 13.9 ± 5.3 mmHg, p < 0.0001), associated with a significant regression of the left ventricular mass index in the stentless (p < 0.0001) but not in the stented group (p = 0.2).

CONCLUSION

Our data support that full-root stentless aortic valve replacement can be performed without adversely affecting the early morbidity or mortality in patients operated on for aortic valve stenosis provided that the coronary ostia are not heavily calcified. The additional time necessary for the full-root stentless compared to the classical stented aortic valve replacement is therefore not detrimental to the early clinical outcomes and is largely rewarded in patients with aortic stenosis by lower transvalvular gradients at mid-term and a better regression of their left ventricular mass index.

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

OBJECTIVES

Stentless aortic valve replacements show improved hemodynamics due to larger orifice area and lower transvalvular gradients in short and mid-term follow-up. Hemodynamic long-term behavior and the adaptation of the left ventricle as well as valve-durability in patients aged ≤60 years remains unclear.

METHODS

7 to 16 years after aortic valve replacement, 54 patients (mean age at operation 53.1 ± years) received echocardiography and clinical examination. Mean follow-up time was 10.8 ± 2.2 years. Evaluated were NYHA class, transvalvular gradients, estimated aortic valve orifice area, degree of aortic valve insufficiency, left ventricular mass and function.

RESULTS

At follow-up only one patient presented with NYHA class III. All other patients were in NYHA class I or II. Maximum and mean pressure gradients of the prostheses were 16.3 ± 7.4 mmHg and 9.1 ± 4.2 mmHg, respectively. Compared to echocardiography at discharge the mean pressure gradients dropped 18.0% (2.0 ± 0.9 mmHg) and stayed stable until 14 years after the operation. Only 5 patients showed relevant regurgitation (at 13-16 years after valve replacement), 49 showed no or trivial regurgitation. Left ventricular mass had decreased 26.5% (107.9 ± 18.5 g). Left ventricular ejection fraction (LVEF) had increased in most patients and decreased in only one. For patients with preoperatively impaired left ventricular function an increase of LVEF of 13.1 ± 3.1% was seen.

CONCLUSION

Porcine stentless aortic valves provide excellent hemodynamic long-term results without significant rise of transvalvular pressure gradients or relevant insufficiencies until 14 years after implantation, leading to sustained decrease of left ventricular mass and improvement of left ventricular function.

In-vivo assessment of the morphology and hemodynamic functions of the BioValsalva™ composite valve-conduit graft using cardiac magnetic resonance imaging and computational modelling technology

BACKGROUND

The evaluation of any new cardiac valvular prosthesis should go beyond the classical morbidity and mortality rates and involve hemodynamic assessment. As a proof of concept, the objective of this study was to characterise for the first time the hemodynamics and the blood flow profiles at the aortic root in patients implanted with BioValsalva™ composite valve-conduit using comprehensive MRI and computer technologies.

METHODS

Four male patients implanted with BioValsalva™ and 2 age-matched normal controls (NC) underwent cardiac magnetic resonance imaging (MRI). Phase-contrast imaging with velocity-mapping in 3 orthogonal directions was performed at the level of the aortic root and descending thoracic aorta. Computational fluid dynamic (CFD) simulations were performed for all the subjects with patient-specific flow information derived from phase-contrast MR data.

RESULTS

The maximum and mean flow rates throughout the cardiac cycle at the aortic root level were very comparable between NC and BioValsalva™ patients (541 ± 199 vs. 567 ± 75 ml/s) and (95 ± 46 vs. 96 ± 10 ml/s), respectively. The maximum velocity (cm/s) was higher in patients (314 ± 49 vs. 223 ± 20; P = 0.06) due to relatively smaller effective orifice area (EOA), 2.99 ± 0.47 vs. 4.40 ± 0.24 cm2 (P = 0.06), however, the BioValsalva™ EOA was comparable to other reported prosthesis. The cross-sectional area and maximum diameter at the root were comparable between the two groups. BioValsalva™ conduit was stiffer than the native aortic wall, compliance (mm2 • mmHg(-1) • 10(-3)) values were (12.6 ± 4.2 vs 25.3 ± 0.4.; P = 0.06). The maximum time-averaged wall shear stress (Pa), at the ascending aorta was equivalent between the two groups, 17.17 ± 2.7 (NC) vs. 17.33 ± 4.7 (BioValsalva™ ). Flow streamlines at the root and ascending aorta were also similar between the two groups apart from a degree of helical flow that occurs at the outer curvature at the angle developed near the suture line.

CONCLUSIONS

BioValsalva™ composite valve-conduit prosthesis is potentially comparable to native aortic root in structural design and in many hemodynamic parameters, although it is stiffer. Surgeons should pay more attention to the surgical technique to maximise the reestablishment of normal smooth aortic curvature geometry to prevent unfavourable flow characteristics.

The freestyle aortic bioprosthesis: a systematic review

BACKGROUND

The Medtronic Freestyle bioprosthesis (FSB) provides an alternative to other prostheses for both aortic valve and aortic root surgery. This paper is a systematic review of the post-operative outcomes in patients with aortic valve and/or aortic root disease following FSB implantation.

METHODS

Electronic databases were searched for primary analysis, prospective randomised studies comparing the FSB with an alternative aortic prosthesis were included. Additionally, case series that included data for at least 100 individual operated patients were used for secondary analysis.

RESULTS

Among three identified randomised studies, 199 FSB cases were compared with homografts, and stented and an alternative stentless bioprosthesis. The FSB showed comparable hospital mortality (4.5% vs. 5.3%) and eight-year actuarial survival (80±5.0% versus 77±6.0%) with the homograft (respectively) and comparable reduction in left ventricular mass index relative to other prosthesis types. Over 6000 individual patients were included in the selected 15 case series. Weighted mean operative mortality, neurological event rate and five-year actuarial survival was 5.2%, 5.5% and 77.8%, respectively.

CONCLUSION

The FSB performed comparably against alternative prostheses regarding in-hospital mortality, long-term survival and reduction in left ventricular mass index. Included case series demonstrated robust post-operative outcomes in both the short and long term.

Normal aortic valves stay open much longer in systole than porcine substitutes

OBJECTIVE

To compare the opening mechanics of porcine valve substitutes with those of a normal human aortic valve.

BACKGROUND

All commercially available porcine valves are pretreated with glutaraldehyde. This study was undertaken to evaluate the consequences of such treatment on valve mechanics.

METHODS

The opening mechanics of the aortic valve, especially the time taken to open fully from a closed position, and the duration for which the valve is maximally open, were compared in a normal aortic valve, a stent-mounted porcine valve, and a stentless porcine valve, using a finite element model.

RESULTS

Despite a 4-fold higher gradient, stent-mounted porcine valves were slower in attaining the fully open position, and the time for which the valve was fully open was almost 25% less than a normal valve. In stentless valves, the compliant root made the initial opening mechanics similar to those of a normal valve. Once this effect was over, the effect of porcine leaflet properties took over, and there was a corresponding delay in the valve opening.

CONCLUSIONS

Fixing the root with a stent and stiffening the leaflets with glutaraldehyde result in delayed valve opening and decrease the duration for which the valve is fully open, thus contributing to inferior hemodynamics.

The Perceval S aortic valve has the potential of shortening surgical time: does it also result in improved outcome?

BACKGROUND

Sutureless aortic valve prostheses have the potential of shortening surgical time. However, whether shorter operative times may also result in improved patient outcomes remains to be established.

METHODS

One hundred patients underwent minimally invasive isolated aortic valve replacement. Of these, 50 patients received a Perceval (Sorin Group, Saluggia, Italy) bioprosthesis (group P) and 50 patients received a non-Perceval valve (group NP).

RESULTS

The group P patients were older (77.5 ± 5.3 versus 71.7 ± 10 years, p = 0.001) and at higher risk (logistic European System for Cardiac Operative Risk Evaluation [EuroSCORE] 9.9 ± 6.5 versus 4.3 ± 1, p = 0.001) than group NP patients. One implant failure occurred in group P (p = 0.5), and conversion to full sternotomy was necessary in 1 patient from each group. Aortic cross-clamp and cardiopulmonary bypass times were 39.4% and 34% shorter in group P (both p < 0.001). Within 30 days, a total of 5 patients died (2 in group P and 3 in group NP, p = 0.5). No significant differences were observed between groups in postoperative arrhythmias and need for pacemaker implantation (p = 0.3 and p = 0.5, respectively). Despite the higher surgical risk, group P patients less frequently required blood transfusion (1.1 ± 1.1 units versus 2.3 ± 2.8 units, p = 0.007), and had a shorter intensive care unit stay (1.9 ± 0.7 versus 2.8 ± 1.9 days, p = 0.002) and a shorter intubation time (9.2 ± 3.6 hours versus 15 ± 13.8 hours, p = 0.01). Group NP patients had a mean prosthesis size significantly smaller than for group P (23 ± 2 mm versus 23.9 ± 1.1 mm, p = 0.01). The Perceval valve provided comparable hemodynamic performance to that of non-Perceval valves (mean gradient 8.4 ± 6 mm Hg versus 10 ± 4.9 mm Hg, p = 0.24).

CONCLUSIONS

Sutureless implantation of the Perceval valve is associated with shorter cross-clamp and cardiopulmonary bypass times, resulting in improved clinical outcome. In addition, it compares favorably with conventional valves in terms of mortality and outcome variables.

Stentless aortic valve replacement in the young patient: long-term results

Background

Stentless aortic valve replacement (SAVR) became a common surgical procedure to treat aortic valve disease, as it offers larger orifice area and improved hemodynamics. The aim of our single-centre retrospective study was to assess long term results of first generation stentless aortic valves in young patients, where mechanical prostheses are considered first line therapy.

Methods

From 1993 to 2001, 188 (149 male and 39 female) patients (≤60 years) underwent SAVR. Indications were in 63.3% stenosis or mixed lesions and in 36.7% isolated regurgitation. Mean age of patients at surgery was 53.1 ± 7.1 years. Associated procedures were performed in 60 patients (31.9%). Follow-up data were acquired through telephone interviews. Follow-up was 90.4% complete at a mean of 8.8 ± 4.7 years. Total follow-up was 1657.6 patient-years with a maximum of 17 years.

Results

Overall hospital mortality was 3.2% (2.5% for isolated SAVR). Overall actuarial survival-rate at 10/15 years and freedom from reoperation at 10/14 years were 73.0% ± 3.5%/ 55.8% ± 5.4% and 81.0% ± 3.4%/ 58.0% ± 7.5%, respectively. For isolated SAVR, actuarial survival at 10/15 years and freedom from reoperation at 10/14 years were 70.1% ± 4.4%/ 64.1% ± 4.8% and 83.1% ± 4.0%/ 52.9% ± 9.0%, respectively. Reoperation was performed in 42 patients (22.3%) due to structural valve deterioration and endocarditis. Age (≤50 years) and associated procedures did not significantly lower survival and freedom from reoperation, however, small prosthesis sizes (≤25 mm) did.

Conclusion

In patients aged 60 and younger, SAVR provides reliable long-term results especially for larger aortic valves.

Clinical and echocardiographic outcomes after implantation of the Trifecta aortic bioprosthesis: an initial single-centre experience

OBJECTIVES

The Trifecta valve (St. Jude Medical) was introduced into clinical practice as a tri-leaflet stented pericardial valve designed for supra-annular placement in the aortic position. The present study aims to evaluate the preliminary results with this new bioprosthesis.

METHODS

Seventy patients underwent aortic valve replacement (AVR) with the Trifecta valve between August 2010 and December 2011. Thirty-three patients were male and 37 were female (52.9%). Mean age was 74.65 ± 7.63 (range 47-90 years). Prevalent cause of AVR was aortic stenosis in 64 (91.43%) patients. The mean preoperative pressure gradient was 50 ± 17 (range 20-84 mmHg), and the mean aortic valve area was 0.77 ± 0.33. Five (7.14%) patients were operated on due to aortic valve endocarditis. One patient was operated on due to isolated, severe aortic insufficiency. All patients were in New York Heart Association functional class III or IV. Twenty-eight (40%) patients underwent concomitant procedures.

RESULTS

Concomitant procedures were coronary artery bypass grafting (n = 25), mitral valve replacement (n = 1), ablation of atrial fibrillation (n = 1) and septal myomectomy (n = 1). There were no intraoperative deaths. The 30-day in-hospital mortality was 2.85% (2 of 70). One late death occurred during the in-hospital stay due to a multiorgan failure on postoperative day 60. There were 2 (2.85%) perioperative strokes. Mean pressure gradient decreased significantly from a preoperative value of 50 ± 17 mmHg to an intraoperative gradient of 9 ± 4 mmHg (Table 3). The mean gradients were 14, 11, 11, 8 and 6 mmHg for the 19, 21, 23, 25 and 27 mm valve size, respectively. No prosthesis dislocation, endocarditis, valve thrombosis or relevant aortic regurgitation was observed at discharge.

CONCLUSIONS

The initial experience with the Trifecta valve bioprosthesis shows excellent outcomes with favourable early haemodynamics. Further studies with longer follow-up are needed to confirm those preliminary results.

Long-Term Clinical and Echocardiographic Follow-Up of the Freestyle Stentless Aortic Bioprosthesis

Background—

Stentless aortic bioprostheses were designed to provide enhanced hemodynamic performance and potentially greater longevity. The present report describes the outcomes of patients with the Freestyle stentless bioprosthesis followed for ≤18 years.

Methods and Results—

Between 1993 and 2011, 430 patients underwent primary aortic valve replacement with a Freestyle bioprosthesis in the subcoronary position. Mean age was 68.2±8.2 years. All of the clinical and echocardiographic data were collected prospectively. Mean overall follow-up was 9.1±4.4 years and was complete in all of the patients. In-hospital mortality was 3.5% (n=15). Overall, 10- and 15-year survival were 60.7% and 35.0%, respectively. Fifty-one patients required reoperation during follow-up, including 27 for structural valve deterioration (SVD). Overall, freedom from reoperation was 91.0% and 75.0% at 10 and 15 years, whereas freedom from reoperation for SVD was 95.9% and 82.3%, respectively. At 10 and 15 years, freedom from reoperation for SVD was 94.0% and 62.6% for patients <60 years of age and 96.3% and 88.4% for patients ≥60 years of age ( P =0.002). The median time to explant for SVD was 10.7 years. SVD presented mostly as acute, severe aortic insufficiency attributed to leaflet tear (77.8%). The independent risk factors for reoperation for SVD were age <60 years ( P =0.001) and dyslipidemia ( P =0.02).

Conclusions—

Aortic valve replacement with the Freestyle bioprosthesis in a subcoronary position provides good long-term clinical and echocardiographic outcomes for patients >60 years of age. Severe aortic insufficiency with leaflet tear is the major mode of SVD leading to reoperation in these patients.

An alternative subcoronary implantation technique decreases the risk of complete heart block after stentless aortic valve replacement

Context:

Stentless aortic valve prostheses have excellent hemodynamic profiles, but may be associated with an increased postoperative heart block when compared to conventional prostheses.

Aims:

To assess the effect of an alternative subcoronary implantation technique on postoperative complete heart block (CHB) and permanent pacemaker implantation (PPI) following aortic valve replacement (AVR) with stentless tissue valves.

Settings and Design:

A total of 130 consecutive patients undergoing AVR with stentless tissue valves by a single surgeon were studied retrospectively.

Materials and Methods:

A stentless tissue valve was implanted into 80 patients using the conventional modified subcoronary implantation technique, and 50 patients received a stentless tissue valve by an alternative subcoronary technique in which the inflow suture line is raised at the level of right-non coronary commissure. Data were collected at the time of hospital discharge and at 6–12 months postoperatively.

Statistical Analysis Used:

Independent samples t-test was used to compare continuous variables, and categorical variables were compared with the chi-square test.

Results:

Use of this new method reduced postoperative CHB (4.0% vs. 16.3%, P = 0.033), with fewer patients requiring PPI in the early postoperative period (6.0% vs. 18.8%, P = 0.041). Echocardiographic examination showed no differences in the effective orifice area, peak and mean aortic valve gradients, or left ventricular mass index between groups. Trivial or mild aortic regurgitation was found in 3.9% of patients with the conventional modified technique and 4.0% of patients undergoing the alternative technique, during follow-up (P > 0.05).

Conclusions:

Compared to the conventional subcoronary implantation technique, the alternative subcoronary implantation technique reduces the incidence of new CHB and the requirement of PPI following AVR with stentless tissue valves while preserving mid-term hemodynamic function.

The Sorin Freedom Stentless Pericardial Valve: Clinical and Echocardiographic Performance at 10 years

Objective:

The Sorin Pericarbon Freedom (SPF) is a stentless valve made of pericardium clinically available in 1990. We report the clinical and hemodynamic performance of the SPF at 10 years.

Methods:

From April 2000 to December 2005, 85 patients with a mean age of 75 ± 6 years (range 57–86), underwent aortic valve replacement (AVR) with an SPF. Mean left ventricular ejection fraction was 58 ± 10% (range 29–86%) and mean peak transvalvular gradient (PG) 86 ± 24 mm Hg. Clinical evaluation was performed at 3, 6, 12 months, and yearly thereafter.

Results:

There were 2 operative deaths (2.4%). Follow-up ranged from 2 to 135 months (mean 78 ± 32 months) and was 99% complete. There were 35 late deaths, 7 of which were valve-related, with an actuarial survival of 45 ± 8% at 10 years. Structural SPF deterioration occurred in 2 patients, with an actuarial freedom of 96 ± 3%. A total of 4 patients were re-operated, 2 because of structural deterioration, 1 because of endocarditis, and 1 because of sinotubular junction dilatation; freedom from reoperation was 93 ± 4% at 10 years. At last clinical control, 41 patients (89%) were in NYHA class I or II. Mean SPF effective orifice area varied from 1.55 ± 0.66 cm2 for size 21 mm to 2.33 ± 0.86 cm2 for size 27 mm; PG varied from 19 ± 10 mm Hg for size 21 mm to 11 ± 6 mm Hg for size 27 mm. Left ventricular mass index decreased from 213 ± 51 gm/m2 to 157 ± 436 gm/m2 (p<0.001).

Conclusions:

The SPF has demonstrated overall good results in terms of valve durability and freedom from valve-related complications up to 10 years, with excellent hemodynamic performance.

Stentless aortic valve replacement: an update

Although porcine aortic valves or pericardial tissue mounted on a stent have made implantation techniques easier, these valves sacrifice orifice area and increase stress at the attachment of the stent, which causes primary tissue failure. Optimizing hemodynamics to prevent patient–prosthetic mismatch and improve durability, stentless bioprostheses use was revived in the early 1990s. The purpose of this review is to provide a current overview of stentless valves in the aortic position. Retrospective and prospective randomized controlled studies showed similar operative mortality and morbidity in stented and stentless aortic valve replacement (AVR), though stentless AVR required longer cross-clamp and cardiopulmonary bypass time. Several cohort studies showed improved survival after stentless AVR, probably due to better hemodynamic performance and earlier left ventricular (LV) mass regression compared with stented AVR. However, there was a bias of operation age and nonrandomization. A randomized trial supported an improved 8-year survival of patients with the Freestyle or Toronto valves compared with Carpentier–Edwards porcine valves. On the contrary, another randomized study did not show improved clinical outcomes up to 12 years. Freedom from reoperation at 12 years in Toronto stentless porcine valves ranged from 69% to 75%, which is much lower than for Carpentier–Edwards Perimount valves. Cusp tear with consequent aortic regurgitation was the most common cause of structural valve deterioration. Cryolife O’Brien valves also have shorter durability compared with stent valves. Actuarial freedom from reoperation was 44% at 10 years. Early prosthetic valve failure was also reported in patients who underwent root replacement with Shelhigh stentless composite grafts. There was no level I or IIa evidence of more effective orifice area, mean pressure gradient, LV mass regression, surgical risk, durability, and late outcomes in stentless bioprostheses. There is no general recommendation to prefer stentless bioprostheses in all patients. For new-generation pericardial stentless valves, follow-up over 15 years is necessary to compare the excellent results of stented valves such as the Carpentier–Edwards Perimount and Hancock II valves.

Stentless Aortic Valve Implantation through an Upper Manubrium-Limited V-Type Ministernotomy

In this piece of work, we attempt to highlight our approach and early experience with minimally invasive aortic valve replacement with aortic Freedom Solo stentless bioprosthesis performed through an upper manubrium-limited ministernotomy in the second intercostal space. The novel suturing technique is required for stentless aortic bioprosthesis implantation, and this, in its turn, will predetermine and influence the surgeon's choice for operative access. In our department, the feasibility of the approach was first assessed; aortic valve was replaced by stentless bioprosthesis in a total of 23 patients (mean age 57 ± 12 years). In all cases, a cardiopulmonary bypass was established by a central ascending aorta cannulation and peripheral percutaneous venous cannula insertion. This approach was found to be technically reproducible and safe. The surgical technique used is described in this article.

Overestimation of the operative risk by the EuroSCORE also in high-risk patients undergoing aortic valve replacement with a stentless biological prosthesis

BACKGROUND

The EuroSCORE generally overestimates the risk of standard aortic valve replacement (AVR). The predictive value of this risk algorithm for high-risk patients undergoing stentless AVR is unclear; therefore, we compared the EuroSCORE prediction with our results in this patient population.

METHODS

One hundred thirty-two patients with a logistic EuroSCORE of at least 10 (mean, 25) underwent primary isolated AVR with a stentless bioprosthesis between January 2004 and December 2007. Seventy-one patients (54%) were octogenarians or nonagenarians, 62 (47%) had a reduced left ventricular ejection fraction, and 46 (35%) had an extracardiac arteriopathy.

RESULTS

Maximum/mean pressure gradients for the implanted valve prostheses were 19/11 mm Hg, and the mean regurgitation grade was 0.06. Stroke occurred in 3% of the patients, and a permanent pacemaker was required in 3%. The 30-day mortality rate was 8%. Another 5% of the patients died after the 30th postoperative day but within the same hospital admission. The predicted mortality was almost 100% greater than the observed mortality.

CONCLUSION

We observed a mortality rate that was 50% lower than that predicted by the logistic EuroSCORE. Therefore, one should not hesitate to use stentless valves in high-risk patients because the EuroSCORE greatly overestimates their surgical risk.