Durability of homografts used to treat complex aortic valve endocarditis

Advantages and challenges in processing and quality control of decellularized heart valves

More than 1000 donated aortic and pulmonary valves from predominantly European tissue banks were centrally decellularized and delivered to hospitals in Europe and Japan. Here, we report on the processing and quality controls before, during and after the decellularization of these allografts. Our experiences show that all tissue establishments, which provide native cardiovascular allografts for decellularization, meet comparably high-quality standards, regardless of their national origin. A total of 84% of all received allografts could be released as cell-free allografts. By far the most frequent reasons for rejection were non-release of the donor by the tissue establishment or severe contaminations of the native tissue donation. Only in 2% of all cases the specification for freedom from cells was not fulfilled, indicating that decellularization of human heart valves is a safe process with a very low discard ratio. In clinical use, cell-free cardiovascular allografts have been shown to be advantageous over conventional heart valve replacements, at least in young adults. These results open the discussion on the future gold standard and funding of this innovative therapeutic option for heart valve replacement.

A Literature Review on the Use of Aortic Allografts in Modern Cardiac Surgery for the Treatment of Infective Endocarditis: Is There Clear Evidence or Is It Merely a Perception?

Infective valve endocarditis is caused by different pathogens and 60% of those involve the aortic valve with valve failure. Although S. aureus is recognized as the most frequently isolated causative bacterium associated with IE in high-income countries, Gram-positive cocci nevertheless play a crucial role in promoting infection in relation to their adhesive matrix molecules. The presence of pili on the surface of Gram-positive bacteria such as in different strains of Enterococcus faecalis and Streptococcus spp., grants these causative pathogens a great offensive capacity due to the formation of biofilms and resistance to antibiotics. The indications and timing of surgery in endocarditis are debated as well as the choice of the ideal valve substitute to replace the diseased valve(s) when repair is not possible. We reviewed the literature and elaborated a systematic approach to endocarditis management based on clinical, microbiological, and anatomopathological variables known to affect postoperative outcomes with the aim to stratify the patients and orient decision making. From this review emerges significant findings on the risk of infection in the allograft used in patients with endocarditis and no endocarditis etiology suggesting that the use of allografts has proved safety and effectiveness in patients with both pathologies.

Homograft Versus Valves and Valved Conduits for Extensive Aortic Valve Endocarditis with Aortic Root Involvement/Destruction: A Systematic Review and Meta-Analysis

Aortic valve infective endocarditis is a life-threatening condition. Patients frequently present profoundly unwell and extensive surgery may be required to correct the underlying anatomical deficits and control sepsis. Periannular involvement occurs in more than 10% of patients with aortic valve endocarditis. Complex aortic valve endocarditis has a mortality rate of 10 to 40%. Longstanding surgical dogma suggests homografts represent the optimal replacement option in complex aortic valve endocarditis; however, there is a paucity of evidence and lack of consensus on the optimal replacement choice. A systematic review and meta-analysis was performed utilizing EMBASE, PubMed, and the Cochrane databases to review articles describing homografts versus aortic valve replacement and/or valved conduit graft implantation for complex aortic valve endocarditis. The outcomes of interest were mortality, reinfection, and reoperation. Eleven studies were included in this meta-analysis, contributing 810 episodes of complex aortic valve endocarditis. All included reports were cohort studies. There was no statistically significant difference in overall mortality (risk ratio [RR] 0.99; 95% confidence interval [CI], 0.61–1.59; p  = 0.95), reinfection (RR 0.89; 95% CI, 0.45–1.78; p  = 0.74), or reoperation (RR 0.91; 95% CI, 0.38–2.14; p  = 0.87) between the homograft and valve replacement/valved conduit graft groups. Overall, there was no difference in mortality, reinfection, or reoperation rates between homografts and other valve or valved conduits in management of complex aortic endocarditis. However, there is a paucity of high-quality evidence in the area, and comparison of valve types warrants further investigation.

Transplantation of cryopreserved human heart valves in Europe: 30 years of banking in Brussels and future perspectives

For over 30 years, our TE has processed, controlled for quality and distributed cryopreserved allograft valves for human application. We present a review of this activity and future perspectives of cardiovascular tissue banking. The donor age and medical/behavioral history are in compliance with the regulations of the EUMS. Allograft morphology and function are evaluated in a class A cleanroom. Tests for viral/bacterial infection, histological control of structure/infection/malignancy and control-rate cryopreservation are performed. A total of 7562 hearts were sent to our TE, whereas 7290 valves (pulmonary, aortic and mitral) were transplanted. The donations increased over time: 1934, 2566 and 3062 hearts were donated during the first, second and third decades (increases of 32.7 and 19.3% during the second and third decades). Likewise, there was a significant increase in transplantations with 2050, 2550 and 2690 valves implanted during the first, second and third decades (24.4 and 5.5% increase during the second and third decades). A total of 4475 pulmonary (61.4%), 2760 aortic (37.9%) and 55 mitral valves (0.7%) were transplanted. Outstanding long-term results in adults and evidence of immune-related deterioration of allografts in neonates and infants were demonstrated. Decellularization was suggested as a solution. One hundred pulmonary and 180 aortic valves were sent for transplantation after decellularization for the ESPOIR and ARISE clinical trials and beyond. The donation and transplantation activity increased progressively. Although cryopreserved valves represent the best substitute for diseased valves, accelerated failure appears after implantation in neonates and infants. The implementation of new technologies, such as decellularization, as a standard procedure for treatment of allograft valves will offer further improvements in allograft quality and increase of durability.

Management of aortic root in type A dissection: Bentall approach

BACKGROUND

We analyzed the results of the modified Bentall procedure in a high-risk group of patients presenting with acute type A aortic dissection (ATAAD).

METHODS

ATAAD patients undergoing a modified Bentall between 1996 and 2018 (n = 314) were analyzed. Mechanical composite conduits were used in 45%, and biological ones using either a bioprosthesis implanted into an aortic graft (33%) or xeno-/homograft root conduits (22%) in the rest. Preoperative malperfusion was present in 34% of patients and cardiopulmonary resuscitation required in 9%.

RESULTS

Concomitant arch procedures consisted of hemiarch in 56% and total arch/elephant trunk in 34%, while concomitant coronary artery surgery was required in 20%. The average cross-clamp and cardiopulmonary bypass times were 126 ± 43 and 210 ± 76 min, respectively, while the average circulatory arrest times were 29 ± 17 min. A total of 69 patients (22%) suffered permanent neurologic deficit, while myocardial infarction occurred in 18 cases (6%) and low cardiac output syndrome in 47 (15%). The in-hospital mortality rate was 17% due to intractable low cardiac output syndrome (n = 29), major brain injury (n = 16), multiorgan failure (n = 6), and sepsis (n = 2). The independent predictors of in-hospital mortality were critical preoperative state (odds ratio [OR], 5.6; p < .001), coronary malperfusion (OR, 3.6; p = .002), coronary artery disease (OR, 2.6; p = .033), and prior cerebrovascular accident (OR, 5.6; p = .002).

CONCLUSIONS

The modified Bentall operation, along with necessary concomitant procedures, can be performed with good early results in high-risk ATAAD patients presenting.

A narrative review of early surgery versus conventional treatment for infective endocarditis: do we have an answer?

The most appropriate strategy and timing for surgery in infective endocarditis (IE) remains an argument of debate. Despite some authors promote the adoption of an early surgical approach (within 48 hours) to limit mortality and complications, no robust randomized trials are available on this argument and the evidence on this subject remain at the "expert opinion" level. Additionally, the different messages promulgated by the American and European guidelines contributed to fuel confusion regarding the relative priority of the surgical over medical therapy in IE. The European Society of Cardiology (ESC) guidelines individuates three level of urgency: emergency surgery, to be performed within 24 hours; urgent surgery, recommended within a few days; elective surgery to be performed after 1-2 weeks of antibiotic therapy. Urgent surgery is recommended for most cases of IE. In the American Heart Association (AHA)'s guidelines define early surgery as "during the initial hospitalization and before completion of a full course of antibiotics." Some of the available evidences showed that are no proven benefits in delaying surgery if a definite diagnosis of IE has been established. However, this argument is controversial across the literature and several factors including the center specific experience can play a role in decision-making. In this review the latest evidences on IE clinical and surgical characteristics along with the current studies on the adoption of an early surgical approach are analyzed to clarify whether enough evidence is available to inform an update of the guidelines.

Sharing of decision-making for infective endocarditis surgery: a narrative review of clinical and ethical implications

Infective endocarditis (IE) is nowadays one of the most challenging disease in cardiac surgery because of its multifaceted clinical and anatomical presentation. Despite the many clinical and surgical advances achieved in the past 60 years, there is a lack of evidence regarding the ideal strategy. The present review aims to investigate and highlight two main novel concepts for the decision-making of the best substitute. Firstly, the concept of an "endocarditis team": a coordinated multidisciplinary effort in the diagnostic work-up, especially in conditions of high risk of embolization or clinical deterioration. A good "endocarditis team" has the role to overcome such problem, in order to ensure a prompt and balanced strategy. Secondly, which ethical considerations are required to drive the choice of valvular substitute. The choice of best valve substitute is a relevant issue of debate, not only with operative but also prognostic and accordingly ethical aftermaths. Many different solutions have been developed to substitute the infected valve. Among these: mechanical prosthesis (MP), biological stented prosthesis (BP), sutureless bioprosthesis and cryopreserved homografts (CHs). Patients need to be informed in detail about the technical issues pertaining the use of these valve substitute. We will discuss the evidences regarding the risk of recurrent infections or future potentially severe calcification of aortic homograft valve and wall (in other words, the failure of the homograft) and the difficulties in managing the reoperation.

A management framework for left sided endocarditis: a narrative review

Left sided endocarditis (LSE) can include the entirety or portion of mitral and/or aortic valve and the structures in their anatomical contiguity and represent a significant portion of emergency surgical activity. Literature and guidelines on the management of LSE relies mainly on observational studies given the difficulty in designing randomized trials in emergency settings. Heart teams (HT) are often called in to difficult decisions on the most appropriate strategy to adopted in case of LSE. Decision-making should take into account the localization and the extension of the infection, patient preoperative status and comorbidities, presence of a previous valve prosthesis and best timing for surgery. Despite evidence suggests that early surgery may improve survival in patients with complicated infective endocarditis (IE), an increased risk of recurrence and postoperative valvular dysfunctions has been reported. The most important factors associated with long-term outcomes are preoperative multiorgan failure, prosthetic mechanical valve IE, vegetation size ≥15 mm, and timing of surgical treatment. Importantly, up to one third of potential candidates do not undergo surgery and these patients experience extremely high mortality rates. Another important point regards the choice of the optimal valve substitute to be used according to the different clinical situation. The lack of RCT in this field and the difficulty to design this type of studies in the case of non-elective conditions further complicates the possibility to achieve a univocal consensus on the best strategy to be adopted in each form of LSE and further validation studies are needed. On the basis of the current evidences a decisional algorithm is proposed summarizing all the crucial aspects in the management of LSE.

Learning From Controversy: Contemporary Surgical Management of Aortic Valve Endocarditis

Aortic valve replacement is the commonest cardiac surgical operation performed worldwide for infective endocarditis (IE). Long-term durability and avoidance of infection relapse are goals of the procedure. However, no detailed guidelines on prosthesis selection and surgical strategies guided by the comprehensive evaluation of the extension of the infection and its microbiological characteristics, clinical profile of the patient, and risk of infection recurrence are currently available. Conventional mechanical or stented xenografts are the preferred choice for localized aortic infection. However, in cases of complex IE with the involvement of the root or the aortomitral continuity, the use of homograft is suggested according to the surgeon and center experience. Homograft use should be counterbalanced against the risk of structural degeneration. Prosthetic bioroot or prosthetic valved conduit (mechanical and bioprosthetic) are also potentially suitable alternatives. Further development of preservation techniques enabling longer durability of allogenic substitutes is required. We evaluate the current evidence for the use of valve substitutes in aortic valve endocarditis and propose an evidence-based algorithm to guide the choice of therapy. We performed a systemic review to clarify the contemporary surgical management of aortic valve endocarditis.

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.

Next-generation tissue-engineered heart valves with repair, remodelling and regeneration capacity

Valvular heart disease is a major cause of morbidity and mortality worldwide. Surgical valve repair or replacement has been the standard of care for patients with valvular heart disease for many decades, but transcatheter heart valve therapy has revolutionized the field in the past 15 years. However, despite the tremendous technical evolution of transcatheter heart valves, to date, the clinically available heart valve prostheses for surgical and transcatheter replacement have considerable limitations. The design of next-generation tissue-engineered heart valves (TEHVs) with repair, remodelling and regenerative capacity can address these limitations, and TEHVs could become a promising therapeutic alternative for patients with valvular disease. In this Review, we present a comprehensive overview of current clinically adopted heart valve replacement options, with a focus on transcatheter prostheses. We discuss the various concepts of heart valve tissue engineering underlying the design of next-generation TEHVs, focusing on off-the-shelf technologies. We also summarize the latest preclinical and clinical evidence for the use of these TEHVs and describe the current scientific, regulatory and clinical challenges associated with the safe and broad clinical translation of this technology.

Comparative Effectiveness of Mechanical Valves and Homografts in Complex Aortic Endocarditis

BACKGROUND

The ideal surgical reconstruction of the aortic root in patients with complex endocarditis is controversial. We compared the short- and long-term outcomes between mechanical valves, bioprostheses, and homografts.

METHODS

We identified all patients undergoing an operation for active complex aortic endocarditis at our institution between 2003 and 2017. We grouped patients according to those who received a mechanical valve, bioprosthesis, or homograft. We used multiple logistic regression and proportional hazards models. To minimize confounding by indication, we used marginal risk adjustment to simulate that every patient would undergo (contrary to fact) all 3 operations.

RESULTS

Of 159 patients with complex active endocarditis, 48 (30.2%) had a valve plus patch reconstruction, and 85 (53.4%) had a root replacement. Of all, 50 (31.5%) had a mechanical valve, 56 (35.2%) had a bioprosthesis, and 53 (33.3%) had a homograft. The groups were similar in age, sex, body mass index, comorbid conditions, organism, abscess location, and mitral involvement (all P > .05). However, patients receiving mechanical reconstructions were more likely to have native valve endocarditis (46% vs 37.5% vs 17%; P = .005) and less likely to undergo root replacement (32% vs 28.6% vs 100%; P < .001). Marginal risk-adjusted operative mortality was lowest for mechanical valves (4.8%) and highest for homografts (16.9%; P = .041). Long-term survival after root replacement was worse with homografts than with mechanical valve conduits (adjusted hazard ratio, 2.9; P = .045).

CONCLUSIONS

In patients with complex endocarditis, mechanical valves are associated with similar, if not better, short- and long-term outcomes compared with homografts, even after adjusting for important baseline characteristics and limiting the analysis to root replacements only.

Treatment of aortic valve endocarditis with stented or stentless valve

OBJECTIVE

The study objective was to provide evidence for choosing a bioprosthesis in treating patients with active aortic valve endocarditis.

METHODS

From 1998 to 2017, 265 patients with active aortic valve endocarditis underwent aortic valve replacement with a stented valve (n = 97, 37%) or a stentless valve (n = 168, 63%) with further breakdown into inclusion technique (n = 142, 85%) or total root replacement (n = 26, 15%). Data were obtained from the Society of Thoracic Surgeons database aided with chart review, surveys, and National Death Index data.

RESULTS

The median age of patients was 53 years (43-56) in the stented group and 57 years (44-66) in the stentless group. The stented and stentless groups had high rates of heart failure (54% and 40%), liver disease (16% and 7.7%), prosthetic valve endocarditis (14% and 48%), root abscess (38% and 70%), and concomitant ascending aorta procedures (6.2% and 22%), respectively. The stentless group required permanent pacemakers in 11% of cases. Operative mortality was similar between groups (6.2% and 7.1%). The 5-year survival was 52% and 63% in the stented and stentless groups, respectively. Significant risk factors for long-term mortality included liver disease (hazard ratio, 2.38), previous myocardial infarction (hazard ratio, 1.64), congestive heart failure (hazard ratio, 1.63), and renal failure requiring dialysis (hazard ratio, 4.37). The 10-year cumulative incidence of reoperation was 12% and 3.4% for the stented and stentless groups, respectively. The 10-year freedom from reoccurrence of aortic valve endocarditis was 88% for the stented and 98% for the stentless groups.

CONCLUSIONS

Both stented and stentless aortic valves are appropriate conduits for replacement of active aortic valve endocarditis for select patients.

Surgical Options for Aortic Root Replacement in Destructive Endocarditis

Objective

To analyze patients’ preoperative characteristics, surgical data, postoperative courses, and short- and long-term outcomes after implantation of different full-root prostheses for destructive aortic valve endocarditis.

Methods

Between 1999 and 2018, 80 patients underwent aortic root replacement due to infective endocarditis in our institution. We analyzed the abovementioned data with standard statistical methods.

Results

The Freestyle stentless porcine prostheses were implanted in 53 (66.25%) patients, biological valve conduits in 13 (16.25%), aortic root homografts in nine (11.25%), and mechanical valve conduits in five (6.25%). There were no significant preoperative differences between the groups. The incidence of postoperative complications and intensive care unit length of stay did not differ significantly between the groups. The 30-day mortality rate was low among Freestyle patients (n=8, 15.1%) and high in the mechanical conduit cohort (n=3, 60%), though with borderline statistical significance (P=0.055). The best mean survival rates were observed after homograft (13.7 years) and stentless prosthesis (8.1 years) implantation, followed by biological (2.8 years) and mechanical (1.4 years) conduits (P=0.014). The incidence of reoperations was low in the mechanical conduit group (0) and stentless bioroot group (n=1, 1.9%), but two (15.4%) patients with biological conduits and three (33.3%) patients with homografts required reoperations in the investigated follow-up period (P=0.005).

Conclusion

In patients with the destructive form of aortic valve endocarditis, homografts and stentless porcine xenografts offer better survival rates than stented valve conduits; however, the reoperation rate among patients who received homograft valves is high.

The use of allogenic and autologous tissue to treat aortic valve endocarditis

The surgical treatment of aortic valve endocarditis (AVE) is generally performed using conventional mechanical or biological xenograft prosthesis, with limited use of aortic homograft (Ao-Homo) or pulmonary autograft (PA). Clinical evidence has demonstrated a clear contradiction between the proven benefits of Ao-Homo and PA in the context of infection and the very limited use of allogenic or autologous tissue in everyday clinical practice. This review aims to summarize the most recent and relevant literature in order to foster the scientific debate on the use of the use of allogenic and autologous tissue to treat AVE. The decisional process of the Heart Team should also include the preferences of the patient, his/her family, the general cardiologist or primary care physician. The use of allogenic or autologous valve substitute is beneficial if there is a high risk of recurrence of infection, avoiding extensive adhesiolysis and debridement of synthetic material. In any case, those procedures should be performed by highly trained centers to optimize outcomes.

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.

Homograft Versus Conventional Prosthesis for Surgical Management of Aortic Valve Infective Endocarditis: A Systematic Review and Meta-analysis

OBJECTIVE

Surgical management of aortic valve infective endocarditis (IE) with cryopreserved homograft has been associated with lower risk of recurrent IE, but there is equipoise with regard to the optimal prosthesis. This systematic review and meta-analysis were performed to compare outcomes between homograft and conventional prosthesis for aortic valve IE.

METHODS

We searched MEDLINE database to September 2017 for studies comparing homograft versus conventional prosthesis. The main outcomes were all-cause mortality, recurrent IE, and reoperation.

RESULTS

There were 18 included comparative observational studies with 2232 patients (median follow up = 5 [interquartile range: 2-7] years, 30% prosthetic valve endocarditis); four studies were adjusted for baseline differences. There were no differences in perioperative mortality or stroke despite a greater proportion of staphylococcal endocarditis, abscess, and root replacements but less multivalve involvement in the homograft group. Long-term outcomes of all-cause mortality [incidence rate ratio (IRR) = 1.03, 95% confidence interval (CI) = 0.81-1.31, P = 0 .83, for unmatched, and IRR = 0.82, 95% CI = 0.36-1.84, P = 0.63, for matched studies], recurrent endocarditis (IRR = 1.01, 95% CI = 0.53-1.93, P = 0.96, for unmatched, and IRR = 1.04, 95% CI = 0.49-2.19, P = 0.92, for matched studies), and reoperation (IRR = 1.60, 95% CI = 0.80-3.21, P = 0.18, for unmatched, and IRR = 3.17, 95% CI = 0.52-19.44, P = 0.21, for matched studies) were not different comparing homograft versus conventional prosthesis. There was a significantly increased need for reoperation with homograft versus mechanical prosthetic valves, but this comparison was based on limited data.

CONCLUSIONS

Homografts and conventional prostheses offer similar survival and freedom from recurrent endocarditis and reoperation for aortic valve IE. Homografts may be associated with greater risk of reoperation compared with mechanical valves.

Long-term Evaluation of the Ross Procedure in Acute Infective Endocarditis

Optimal valve substitute for young patients with aortic valve endocarditis remains controversial. Given its better resistance to infection, the Ross procedure is an attractive alternative to prosthetic valve replacement or homograft implantation. The objective of this study was to assess long-term outcomes of the Ross procedure in this indication. From January 1991 to April 2017, 190 patients underwent a Ross procedure at our institution. Acute endocarditis was the indication for operation in 19 patients, including 6 patients with a bicuspid aortic valve. The pulmonary autograft was implanted as freestanding root replacement in all patients. The clinical follow-up is 100% complete, with a mean of 12.0 ± 5.7 years. The mean age of the study population was 35.9 ± 11.5 years. Moderate or severe aortic regurgitation was present in 84.2% of the patients. Systemic embolization had occurred in 36.8% of the patients. The mean aortic cross-clamp time was 126 ± 24 minutes. The median length of stay on the intensive care unit was 1 day. Mortality at 30 days was 5.3% (1 patient with gastrointestinal bleeding). Echocardiography at hospital discharge documented no or trivial aortic regurgitation in all patients. No case of recurrent endocarditis affecting the autograft occurred. One patient (0.4% per patient-year) was reoperated 1.8 years after the Ross procedure for homograft endocarditis. Three patients (15.8%) were reoperated for autograft aneurysm. The Ross procedure is a safe and effective alternative to prosthetic valve replacement or homograft implantation in selected young patients with acute endocarditis with a low rate of recurrent infection.

Exclusion of Complex Paraannular Aortic Abscess With the Freestyle Xenograft

Destructive aortic valve endocarditis is a serious condition that can result in aortoventricular disjunction. The appropriate surgical approach for severe excavating lesions remains a matter of debate. Homografts, prosthetic valves associated with a pericardial patch for annulus repair, and prosthetic valve conduits can be used. We report the technical issue of subcoronary inclusion of the full root Freestyle xenograft for complicated aortic endocarditis extending to the left ventricular outflow tract.

Iranian homograft heart valves: assessment of durability and late outcome

Durability and the rate of complications of homograft heart valves, adjusted for patient-related contributors and surgical techniques, rely mainly on the quality of allografts which in turn are mirrored in the donor characteristics and most importantly recovery and processing procedures. Aimed to assess the quality, a study was conducted to figure out the durability and late outcome following homograft replacement with valved conduits procured by the Iranian Tissue Bank. Retrospectively, the pre-implantation, perioperative and follow-up data of 400 non-consecutive recipients of cryopreserved heart valves (222 pulmonary and 178 aortic) from 2006 to 2015 were collected and analyzed in terms of variables reflecting late outcome including adverse events and durability. In the context of durability, the event of interest was defined as the need for homograft replacement and homograft-related death. The mean follow-up time (SD) of study entrants (male/female ratio, 1.4) was 49.8 (36.3) months. Median age at the time of implantation was 11 years. Total 10-years mortality was 21 % (84/400), including 66.7 % early (30-days mortality: 56/84) and 33.3 % late (28/84). Overall late complication rate was 2 %. Median survival time was 120 months (95 % CI 83.3-156.6). The pulmonary valves appeared to be more durable (P value <0.001) and survival probabilities in small sized grafts were lower (P value 0.008). One-, five-, and ten-year graft survival was 82, 76 and 73 %, respectively. The evidences suggest that the homografts function satisfactory with low rate of late complications; nevertheless, more emphasis should be given to make long-term durability comparable.

Over 20 years experience with aortic homograft in aortic valve replacement during acute infective endocarditis

OBJECTIVES

Despite the controversy, the aortic homograft is supposedly the best option in acute infective endocarditis (AIE), due to its resistance to reinfection. However, the technical complexity and the risk of structural deterioration over time have limited its utilization. The aim of this study was to evaluate the long-term results of aortic homograft for the treatment of infective endocarditis in our institution with particular attention to predictors of survival and homograft reoperation.

METHODS

The cohort includes 112 patients who underwent aortic valve replacement with an aortic homograft for AIE between January 1990 and December 2014.

RESULTS

Fifteen patients (13.4%) died during the first 30 days after the operation. Two patients were lost to follow-up after discharge from the hospital; therefore, 95 patients were available for long-term analysis. The median duration of follow-up was 7.8 years (IQR 4.7-17.6). Five patients (5.3%) suffered a recurrence of infective endocarditis (1 relapse and 4 new episodes). Sixteen patients (16.8%) were reoperated for structural valve degeneration (SVD; n = 14, 87.5%) or for infection recurrence (n = 2, 12.5%). Freedom from homograft reoperation for infective endocarditis or structural homograft degeneration at 10 and 15 years postoperatively was 86.3 ± 5.5 and 47.3 ± 11.0%, respectively. For patients requiring homograft reoperation, the median interval to reintervention was 11.6 years (IQR 8.3-14.5). Long-term survival was 63.6% (95% CI 52.4-72.8%) and 53.8% (95% CI 40.6-65.3%) at 10 and 15 years, respectively.

CONCLUSIONS

The use of aortic homograft in acute aortic valve endocarditis is associated with a remarkably low risk of relapsing infection and very acceptable long-term survival. The risk of reoperation due to SVD is significant after one decade especially in young patients. The aortic homograft seems to be ideally suited for reconstruction of the aortic valve and cardiac structures damaged by the infective process especially in early surgery.

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.

Ross procedure is a safe treatment option for aortic valve endocarditis: Long-term follow-up of 42 patients

BACKGROUND

Aortic root replacement with a pulmonary autograft (Ross procedure) can be performed as a treatment of aortic valve endocarditis, avoiding prosthetic valve implantation in septic context. We sought to assess long-term outcomes of the Ross procedure in this indication.

METHODS

From April 1992 to March 2009, the intervention was performed in 42 patients (mean age 34 ± 8 years) suffering from an active or ancient aortic valve endocarditis. 36% of the patients had extensive perivalvular involvement, and surgery was urgent in 18 patients (43%). We performed a prospective clinical and echocardiographic follow-up of this population.

RESULTS

Median follow-up was 10 years (4-21 years). Overall survival at 10 and 15 years was respectively 87 ± 5% and 81 ± 8%. Perioperative mortality was 4.7% (2 patients) and no late cardiac death was reported. Eight patients (19%) underwent repeat surgery for autograft and/or homograft dysfunction at a median time of 8.4 years (3 months-18 years). Rate of recurrent endocarditis was low (7%-3 patients), including 1 in a context of persistent intravenous drug abuse. Clinical follow-up showed good functional status for all patients with NYHA ≤ II, and less than 25% of patients requiring cardiovascular medication. Late echocardiographic follow-up demonstrated well-functioning autograft and homograft, with only one severe aortic regurgitation, and one significant increase in pulmonary mean gradient.

CONCLUSION

The Ross procedure in aortic valve endocarditis is an interesting alternative to prosthetic valvular replacement in a selected population, with a high rate of survival free from any cardiovascular event or medication requirement.