Advantage of autograft and homograft valve replacement for complex aortic valve endocarditis

Polymeric Heart Valves: Do They Represent a Reliable Alternative to Current Prosthetic Devices?

With the increasing number of people suffering from heart valve diseases (e.g., stenosis and/or insufficiency), the attention paid to prosthetic heart valves has grown significantly. Developing a prosthetic device that fully replaces the functionality of the native valve remains a huge challenge. Polymeric heart valves (PHVs) represent an appealing option, offering the potential to combine the robustness of mechanical valves with the enhanced biocompatibility of bioprosthetic ones. Over the years, novel biomaterials (such as promising new polymers and nanocomposites) and innovative designs have been explored for possible applications in manufacturing PHVs. This work provides a comprehensive overview of PHVs' evolution in terms of materials, design, and fabrication techniques, including in vitro and in vivo studies. Moreover, it addresses the drawbacks associated with PHV implementation, such as their limited biocompatibility and propensity for sudden failure in vivo. Future directions for further development are presented. Notably, PHVs can be particularly relevant for transcatheter application, the most recent minimally invasive approach for heart valve replacement. Despite current challenges, PHVs represent a promising area of research with the potential to revolutionize the treatment of heart valve diseases, offering more durable and less invasive solutions for patients.

Biological Scaffolds for Congenital Heart Disease

Congenital heart disease (CHD) is the most predominant birth defect and can require several invasive surgeries throughout childhood. The absence of materials with growth and remodelling potential is a limitation of currently used prosthetics in cardiovascular surgery, as well as their susceptibility to calcification. The field of tissue engineering has emerged as a regenerative medicine approach aiming to develop durable scaffolds possessing the ability to grow and remodel upon implantation into the defective hearts of babies and children with CHD. Though tissue engineering has produced several synthetic scaffolds, most of them failed to be successfully translated in this life-endangering clinical scenario, and currently, biological scaffolds are the most extensively used. This review aims to thoroughly summarise the existing biological scaffolds for the treatment of paediatric CHD, categorised as homografts and xenografts, and present the preclinical and clinical studies. Fixation as well as techniques of decellularisation will be reported, highlighting the importance of these approaches for the successful implantation of biological scaffolds that avoid prosthetic rejection. Additionally, cardiac scaffolds for paediatric CHD can be implanted as acellular prostheses, or recellularised before implantation, and cellularisation techniques will be extensively discussed.

Long-term outcomes of aortic root replacement for endocarditis

BACKGROUND

Infective endocarditis (IE) involving the aortic valve and root is associated with high risk requiring thoughtful surgical decision-making. The impact of valve and conduit choices and patient factors on long-term outcomes in this patient population is poorly documented.

METHODS

From January 1976 to December 2013, 485 patients underwent aortic root and valve replacement at a single institution. Cox's proportional hazard model identified predictors of long-term survival and cumulative incidence functions were compared to assess need for reoperation with death as a competing risk.

RESULTS

Median age at time of operation was 56.6 years (interquartile range: 23.1) with the indication for operation being endocarditis in 14.6% (n = 71). Stentless root replacement was used in 70% IE versus 34% non-IE (p < .001). Endocarditis at time of root replacement did not have a significant impact on survival through 15 years (IE: 37.3% vs. non-IE: 42.5%; log-rank; p = .13). After multivariable adjustment, survival was similar between patients with and without endocarditis (hazard ratio: 1.1; 95% confidence interval: [0.77, 1.62]; p = .57). Freedom from reoperation at 15 years did not vary significantly by endocarditis status (IE: 95.9% vs. non-IE: 73.6%; p = .07). Among endocarditis patients, freedom from reoperation at 10 years was similar between homograft and stentless bioprosthetic conduits (95.3% vs. 88.5%; log-rank; K-sample; p = .46).

CONCLUSIONS

In a sample with frequent use of stentless prostheses, aortic root replacement for infective endocarditis had acceptable risk and long-term survival similar to root replacement for other indications. In the setting of endocarditis, root replacement with homograft or stentless bioprosthetic root has excellent durability through 15 years.

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.

Current indications for stentless aortic bioprostheses

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

Surgery for Diseases of the Aortic Root

The aortic root is the junction between the heart and aorta, containing the aortic valve and the coronary artery ostia. Various pathologic conditions arise in this region requiring complex surgical correction. These include aneurysmal dilatation with and without aortic regurgitation, acute aortic dissection extending below the sinotubular junction, and infective endocarditis with valve and periannular destruction. Multiple strategies for correction of these complex surgical issues exist, with excellent early results and long-term survival.

Valve selection in aortic valve endocarditis

Aortic prosthetic valve endocarditis (PVE) is a potentially life-threatening disease. Mortality and incidence of infective endocarditis have been reduced in the past 30 years. Medical treatment of aortic PVE may be successful in patients who have a prompt response after antibiotic treatment and who do not have prosthetic dysfunction. In advanced stages, antibiotic therapy alone is insufficient to control the disease, and surgical intervention is necessary. Surgical treatment may be lifesaving, but it is still associated with considerable morbidity and mortality. The aim of surgery is to perform a radical excision of all infected and necrotic tissue, reconstruction of the left ventricle outflow tract, and replacement of the aortic valve. There is no unanimous consensus on which is the optimal prosthesis to implant in this context, and several surgical techniques have been suggested. We aim to analyze the efficacy of the surgical treatment and discuss the issue of valve selection in patients with aortic valve endocarditis.

Fungal prosthetic valve endocarditis with mycotic aneurysm: Case report

Fungal prosthetic valve endocarditis is an extremely severe form of infective endocarditis, with poor prognosis and high mortality despite treatment. Candida albicans is the most common etiological agent for this rare but increasingly frequent condition. We present a case of fungal prosthetic valve endocarditis due to C. albicans following aortic and pulmonary valve replacement in a 38-year-old woman with a history of surgically corrected tetralogy of Fallot, prior infective endocarditis and acute renal failure with need for catheter-based hemodialysis. Antifungal therapy with liposomal amphotericin B was initiated prior to cardiac surgery, in which the bioprostheses were replaced by homografts, providing greater resistance to recurrent infection. During hospitalization, a mycotic aneurysm was diagnosed following an episode of acute arterial ischemia, requiring two vascular surgical interventions. Despite the complications, the patient's outcome was good and she was discharged on suppressive antifungal therapy with oral fluconazole for at least a year. The reported case illustrates multiple risk factors for fungal endocarditis, as well as complications and predictors of poor prognosis, demonstrating its complexity.

The Ross Operation: Clinical Results and Echocardiographic Findings

Between November 2001 and September 2004, 80 patients aged 11 to 56 years (mean, 27.6 years) underwent the Ross operation. The mean preoperative New York Heart Association functional class was 2.37 ± 0.72, and the mean ejection fraction was 52.8% ± 16%. Aortic involvement included stenosis in 19 (24%) patients, regurgitation in 22 (28%), and both in 39 (49%). Root replacement was the technique used in all cases. The mean hospital stay was 5 days, and 74 patients (93%) were followed up for 4–48 months. Four-year actuarial survival rate was 96.25%. Postoperative echocardiography revealed no pulmonary autograft insufficiency in 50 patients (63%), trivial to mild insufficiency in 22 (28%), moderate insufficiency in 2 (3%), and severe insufficiency in one (1%). Two patients required autograft re-intervention. Postoperative echocardiography of the pulmonary homograft valve showed severe stenosis (peak gradient > 50 mm Hg) in 2 patients, and moderate stenosis (peak gradient 25–50 mm Hg) in one. The mean postoperative left ventricular ejection fraction was 51.4%. The Ross operation can be considered an elegant alternative to prosthetic valves in the treatment of aortic valve diseases in developing countries.

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.

Relapsing tricuspid valve endocarditis by multidrug-resistant Pseudomonas aeruginosa in 11 years: tricuspid valve replacement with an aortic valve homograft

Eleven years ago, a 27-year-old non-drug abuser woman was admitted to the hospital due to a burn injury. During the treatment, she was diagnosed with tricuspid valve infective endocarditis caused by multi-drug resistant (MDR) Pseudomonas aeruginosa (P. aeruginosa). She underwent tricuspid valve replacement (TVR) using a bioprosthetic valve, followed by 6 weeks of meropenem antibiotic therapy. Ten years later, she was again diagnosed with prosthetic valve infective endocarditis caused by MDR P. aeruginosa. She underwent redo-TVR with a bioprosthetic valve and was treated with colistin and ciprofloxacin. Ten months later, she was again diagnosed with prosthetic valve infective endocarditis with MDR P. aeruginosa as a pathogen. She underwent a second redo-TVR with a tissue valve and was treated with colistin. Two months later, her fever recurred and she was again diagnosed with prosthetic valve infective endocarditis caused by MDR P. aeruginosa. She eventually underwent a third redo-TVR using an aortic valve homograft and was discharged from the hospital after additional 6 weeks’ of antibiotic therapy. All the strains of P. aeruginosa isolated from each event of infective endocarditis were analyzed by repetitive deoxyribonucleic acid sequence-based polymerase chain reaction (rep-PCR) deoxyribonucleic acid (DNA) strain typing to determine the correlation of isolates. All of the pathogens in 11 years were similar enough to be classified as the same strain, and this is the first case report of TVR using an aortic valve homograft to treat relapsing endocarditis.

Immune response to allograft implantation in children with congenital heart defects

Cryopreserved valved allografts are frequently used in the repair of congenital heart defects in children. Although the longevity of these grafts is generally good in most patients, there continue to be ongoing problems with allograft dysfunction and subsequent failure, particularly in infants and young children. The aim of this review is to discuss the immunogenicity of cryopreserved allograft tissue and measures that may minimize the deleterious effect of the immune system on allograft function and durability.

The Ross procedure in endocarditis: a report of 28 cases

OBJECTIVES

The Ross procedure has received increasing interest as an attractive alternative to a prosthetic aortic valve. Given its presumably greater resistance to infection, the pulmonary autograft is theoretically preferable for active endocarditis. The objective of this retrospective study was to present our experience in aortic valve endocarditis treated using the Ross procedure.

METHODS

Between May 1997 and February 2011, the Ross procedure was performed on 142 patients in our institution. Twenty-eight patients had aortic valve endocarditis at the time of operation. Fourteen patients had urgent or emergency procedures, and 13 had active disease at the time of surgery. Twelve patients were alcoholics and/or drug addicts. Eight patients had an abscess of the aortic annulus. Clinical follow-up was complete.

RESULTS

Hospital mortality was 10.7%. Overall patient survival (± standard deviation) was 47 ± 13% at 10 years with no cardiac-related death during the mean follow-up of 6.4 ± 4.2 years. There were 3 cases of recurrent endocarditis including anterior mitral leaflets endocarditis and right-sided endocarditis to another germ in a drug addict. Four patients required further surgery, 2 on the pulmonary autograft; 18 of the 19 survivors were in New York Heart Association class I. At the final investigation, all patients had no or grade I autograft regurgitation. The mean pressure gradient across the homograft was 9 ± 7.5, 11 ± 9.5 and 15 ± 9.5 mmHg, respectively, for patients between 0-3, 4-9 and >9 years.

CONCLUSIONS

Endocarditis can be treated with good results using the Ross procedure, with a very low rate of recurrence of endocarditis.

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

OBJECTIVES

Few studies have examined the use of stentless Freestyle bioprostheses in patients with active valve endocarditis (VE). The aim of this study was to evaluate outcomes of stentless Freestyle bioprostheses in patients undergoing full-root replacement.

METHODS

From February 2000 to June 2010, 180 patients with VE underwent cardiac surgery at our institution, of which 71 (39.5%) had prosthetic VE. Eighteen patients underwent full-root replacement with Freestyle bioprostheses: 3 patients (16%) had native aortic VE, 14 (78%) had aortic prosthetic VE and 1 (6%) had mitral and aortic prosthetic VE. Mean age was 66.7 ± 10.1, M/F: 6/12, mean logistic EuroSCORE 36.4 ± 21.6. Eight patients (42%) underwent concomitant procedures (two mitral valve replacements, three ascending aorta replacements, one coronary artery bypass grafting (CABG), one ventricular septal disease (VSD) repair, one CABG + ascending aorta + VSD repair).

RESULTS

Two patients (11%) died in-hospital. At the median follow-up of 24 months (range 1-113 months), no death occurred and freedom from reoperation was 87.5% (2 patients for aortic root pseudo-aneurysm at 1 and 23 months). All patients are in NYHA functional class I and have satisfactory echocardiographic data (EF 54.3 ± 8%, peak and mean trans-prosthetic gradients 12 ± 6.7 mmHg and 7.5 ± 3.6 mmHg) with 100% freedom recurrence of VE.

CONCLUSIONS

Our experience shows that root replacement with Freestyle stentless bioprostheses in patient with VE, is associated with low rates of early and mid-term mortality, good haemodynamic performance and low rates of valve-related morbidity as well as low recurrence of infection.

Midterm results of aortic valve replacement with cryopreserved homografts

OBJECTIVE

The aim of this study was to analyze the midterm clinical results of aortic valve replacement with cryopreserved homografts.

MATERIALS AND METHODS

Aortic valve replacement was performed in 40 patients with cryopreserved homograft. The indications were aortic valve endocarditis in 20 patients (50%), truncus arteriosus in 6 patients (15%), and re-stenosis or regurtitation after aortic valve reconstruction in 14 (35%) patients. The valve sizes ranged from 10 to 27mm. A full root replacement technique was used for homograft replacement in all patients.

RESULTS

The 30-day postoperative mortality rate was 12.5% (5 patients). There were four late deaths. Only one of them was related to cardiac events. Overall mortality was 22.5%. Thirty-three patients were followed up for 67±26 months. Two patients needed reoperation due to aortic aneurysm caused by endocarditis. The mean transvalvular gradient significantly decreased after valve replacement (p<0.003). The last follow up showed that the 27 (82%) patients had a normal left ventricular function.

CONCLUSION

Cryopreserved homografts are safe alternatives to mechanical valves that can be used when there are proper indications. Although it has a high perioperative mortality rate, cryopreserved homograft implantation is an alternative for valve replacement, particularly in younger patients and for complex surgical problems such as endocarditis that must be minimalized.

Midterm Follow-up after Cryopreserved Homograft Replacement in the Aortic Position

Background

The long-term results of homografts used in systemic circulation are controversial. We assessed the long-term results of using a cryopreserved homograft for an aortic root or aorta and its branch replacement.

Materials and Methods

From June 1995 to January 2010, 23 patients (male:female=15:8, 45.4±15.6 years) underwent a homograft replacement in the aortic position. The surgical techniques used were aortic root replacement in 15 patients and aortic graft interposition in 8 patients. Indications for the use of a homograft were systemic vasculitis (n=15) and complicated infection (n=8). The duration of clinical follow-up was 65±58 months.

Results

Early mortality occurred in 2 patients (8.7%). Perioperative complications included atrial arrhythmia (n=3), acute renal failure (n=3), and low cardiac output syndrome (n=2). Late mortality occurred in 6 patients (26.1%). The overall survival rates at 5 and 10 years were 66.3% and 59.6%, respectively. Six patients (28.6%) suffered from homograft-related complications.

Conclusion

Early results of homograft replacement in aortic position were favorable. However, close long-term follow-up is required due to the high rate of homograft-related events.

The Ross procedure: state of the art 2011

The purpose of this paper is to review the current literature and practice of the Ross concept of using the autologous pulmonary valve to replace a diseased aortic valve. The potential advantages and disadvantages of these operations will be evaluated in the context of alternative options and relative risks. The different surgical techniques of subcoronary and full root methods will be discussed and important technical aspects reviewed. Long-term outcomes will be described to the extent these are available, including recent publications describing a survival advantage for the Ross. Brief discussions will be presented regarding hemodynamics, child-bearing, endocarditis, and the use of the Ross in pediatric patients as well as biological adaptability of the living pulmonary autograft.

Pulmonary Homografts for Aortic Valve Replacement: Long-term Comparison with Aortic Grafts

<p><b>Objective:</b> The use of homografts for aortic valve replacement (AVR) is an alternative to mechanical or biological valve prostheses, especially in younger patients. This retrospective comparative study evaluated our single-center long-term results, with a focus on the different origins of the homografts.</p><p><b>Methods:</b> Since 1992, 366 adult patients have undergone AVR with homografts at our center. We compared 320 homografts of aortic origin and 46 homografts of pulmonary origin. The grafts were implanted via either a subcoronary technique or the root replacement technique. We performed a multivariate analysis to identify independent factors that influence survival. Freedom from reintervention and survival rates were calculated as cumulative events according to the Kaplan-Meier method, and differences were tested with the log-rank test.</p><p><b>Results:</b> Overall mortality within 1 year was 6.5% (21/320) in the aortic graft group and 17.4% (8/46) in the pulmonary graft group. In the pulmonary graft group, 4 patients died from valve-related complications, 1 patient died after additional heterotopic heart transplantation, and 1 patient who entered with a primary higher risk died from a prosthesis infection. Two patients died from non-valve-related causes. During the long-term follow-up, the 15-year survival rate was 79.9% for patients in the aortic graft group and 68.7% for patients in the pulmonary graft group (<i>P</i> = .049). The rate of freedom from reoperation was 77.7% in the aortic graft group and 57.4% in the pulmonary graft group (<i>P</i> < .001). The reasons for homograft explantation were graft infections (aortic graft group, 5.0%; pulmonary graft group, 6.5%) and degeneration (aortic graft group, 7.5%; pulmonary graft group, 32.6%).</p><p><b>Conclusion:</b> Our study demonstrated superior rates of survival and freedom from reintervention after AVR with aortic homografts. Implantation with a pulmonary graft was associated with a higher risk of redo surgery, owing to earlier degenerative alterations.</p>

Clinical and microbiologic features of multivalvular endocarditis

Multivalvular endocarditis accounts for 15% of all endocarditis. The mechanisms of spread of the infection differs whether endocarditis is only left-sided (involving both the mitral and aortic valves) or bilateral. In left-sided bivalvular endocarditis, it is often a secondary mitral lesion following a primary aortic endocarditis. Multivalvular endocarditis often results in severe and extensive cardiac lesions, well described at echocardiography and frequently responsible for severe heart failure. Patients often need surgery, which consists of radical debridement of all the infected tissue with reconstruction using different types of prostheses; therefore, the surgery may be very complex. The goal should be an early diagnosis of endocarditis to avoid spread of the infection to more than one valve, to improve the prognosis for those patients.

Prosthetic valve endocarditis

Prosthetic valve endocarditis (PVE) is associated with a high mortality during the early and midterm follow-up despite diagnostic and therapeutic improvements; its incidence is increasing and reaches 20-30% of all infective endocarditis episodes. In this review, changes in epidemiology, microbiology, diagnosis and therapy that have evolved in the past few years are analyzed. Staphylococci (both Staphylococcus aureus and coagulase-negative Staphylococcus) have emerged as the most common cause of PVE and are associated with a severe prognosis. Moreover, diagnosis may often be difficult because of its complications and extracardiac manifestations; thus, a comprehensive assessment of the clinical, echocardiographic and laboratory data must be performed. Early PVE, comorbidity, severe heart failure and new prosthetic dehiscence are predictors of mortality. Therapy is not indicated by evidence-based recommendations but mostly on identification of the high-risk conditions. A PVE is a common indication for surgery, whereas medical treatment alone may be achieved in a few instances. Systematic prophylaxis should be used to prevent this severe complication of cardiac valve replacement.

Homograft implantation for aortic valve replacement since 15 years: results and follow-up

BACKGROUND

The use of homografts in aortic valve replacement is an alternative to other prostheses and has been established in our department for 15 years.

METHODS

Since 1992, 360 homografts (HG) have been implanted in adult patients (mean age 51.6 years, 72.8% male). Prospective follow-up was done on an annual basis.

RESULTS

Thirty-day mortality was 5.0% (n = 17); after 5, 10, and 15 years, survival was 88.3%, 84.6%, and 76.0%, respectively. Out of 39 late deaths, 11 were valve-related (10 HG infections, 1 aortic aneurysm). Freedom from reoperation was 99.4% 1 year after operation; after 5, 10, and 15 years it was 94.1%, 78.2%, and 67.3%, respectively. Indications for HG explantation were graft infections (n = 20), calcification (n = 16), regurgitation > grade II (n = 17), perforation (n = 8), and paravalvular leakage (n = 1). Eleven transitoric ischemic attacks, 2 strokes, and 1 cerebral bleeding event were recorded. In echocardiography, the transvalvular pressure gradient changed from 10.55 to 15.02 (P = .004), 19.9 mmHg (P = .056), and 37 mmHg (not applicable) after 5, 10, and 15 years, respectively. Mean HG regurgitation was grade 0.49 before discharge and increased to 1.0 (P < .001), 0.91, and 2.5 after 5, 10, and 15 years, respectively. Ejection fraction increased from 61.9% to 64% after 5 years and to 66% after 10 years (P = .021) and then decreased to 63.5% after 15 years.

CONCLUSIONS

Comparing HG with other valve prostheses, survival and graft durability seem to be confirmed. They are vulnerable to infections. The hemodynamic performance is good, and hemorrhagic or thrombo-embolic events are rare.

Outcome of aortic homograft implantation in 24 cases of severe infective endocarditis

The objective of the study was to evaluate the results of treatment of severe aortic endocarditis with an aortic homograft (an aortic valve and root from a donor) in combination with antibiotic therapy. 24 patients with either aortic prosthetic valve endocarditis (n=16) or severe aortic native valve endocarditis (n=8) with destruction of 1 or more cusps, paravalvular abscess formation and/or cardiac fistulas caused by aggressive bacteria, underwent surgery in 1997-2006. Staphylococcal species were the most common pathogens followed by streptococci. Intravenous antibiotic therapy was started before surgery and continued for at least 4-6 weeks. Three patients with prosthetic valve endocarditis died within the first 24 h after surgery from heart failure. Two of these patients required an additional implantation of a mitral valve prosthesis. Five patients died from non-cardiac causes within 1-7 y of surgery. Within the follow-up period no patients had relapse of endocarditis, and only 1 episode of recurrent endocarditis in an intravenous drug abuser was registered. In conclusion, an aortic homograft in combination with intravenous antibiotics is an excellent option for treatment of severe aortic endocarditis.

Aortic valve endocarditis with aortic wall thickening requires close follow-up for a possible abscess formation

A 67-year-old woman was admitted with aortic valve endocarditis and aortic wall thickening (AWT). Physical examination and laboratory findings yielded infective endocarditis. Echocardiography revealed several small vegetations on the aortic valve, leading to moderate aortic insufficiency together with a small ventricular septal defect. We also became aware of the AWT on and over the aortic root by transesophageal echocardiography (Figure 1). At the one month follow-up period, we also noticed an abscess formation originating from the AWT, which grew into a mature abscess form, day by day (Figure 2). The aortic valve endocarditis, with destruction of the aortic annulus and abscess formation, in this patient, is considered as a grave condition which, essentially, requires an aggressive combined surgical and medical approach. We would like to intimate here with this patient that AWT needs to be considered seriously important in aortic valve endocarditis and, even if the detected vegetations are small, a close follow-up for a possible abscess formation is essential.

Complex Aortic Valve Surgery for Endocarditis Using the Beating-Heart Technique

Objective

Surgical outcomes of aortic valve surgery for endocarditis are poor. Postoperative deterioration of left ventricular (LV) function may contribute to this process. To enhance preservation of myocardial function during aortic valve surgery, we have used a beating-heart technique of myocardial protection without cardioplegic arrest. The aim of this article is to report our initial clinical experience with this technique.

Methods

We identified 30 consecutive patients with endocarditis who underwent aortic valve repair (one patient) or replacement using either a mechanical prosthesis (four patients) or a biologic prosthesis (25 patients) with beating-heart technique. There were 22 men and eight women (mean age 52.8 ± 16.1 years). There were one elective, 22 urgent/emergent, and seven “salvage” operations. Two patients had preoperative stroke, five respiratory failure, three renal failure, 12 congestive heart failure, eight septic shock, and one previous coronary artery bypass grafting. The etiology of the infection was identified in 15 patients (50%). Ten patients had severe, seven moderate, and four mild aortic insufficiency. All patients had vegetations, four had annular abscesses, and two had intracardiac fistulas.

Results

Eight patients (26.6%) had redo procedures. Concomitant procedures included aortic and mitral valve procedure (14 patients), tricuspid valve procedure (two patients), and coronary artery bypass grafting (one patient). Aortic annular reconstruction was required in four patients (13.2%). Total CPB time was 125 ± 67 minutes. Intra-aortic balloon pump was needed in one patient. Two patients (6.6%) had a stroke unrelated to air embolism. Mean follow-up was 7.9 ± 12 months. Early mortality (30 days) was 13.3% (four patients), and late mortality was 10% (three patients). Total mortality was 18% in urgent/emergent cases, and 42% in salvage operations. There was no statistical difference between preoperative and postoperative echocardiographic values of LV function (ejection fraction and fractional shortening). LV end-diastolic dimension decreased postoperatively (P = 0.03), whereas LV end-systolic dimension and left atrial size were unchanged.

Conclusions

Our study did not show improved survival benefits of beating-heart aortic valve surgery compared with historical series in which conventional myocardial protection was used. However, our findings suggest that beating-heart technique is an alternative strategy of myocardial protection that may contribute to preservation of LV function in patients undergoing complex operations for aortic valve endocarditis.

Aortic root abscess with coronary artery involvement: diagnostic and surgical management

We describe two cases of infectious endocarditis in infants complicated by aortic root abscess involving the coronary artery treated by the Ross operation. Multislice computed tomography was important in defining the diagnosis and in planning subsequent surgical management.

The Ross Operation in Children: Effects of Aortic Annuloplasty

BACKGROUND

Autograft dilatation and progressive neoaortic regurgitation after the Ross procedure prompted us to perform routine aortic annuloplasty. The purpose of this review is to evaluate the success of this technical modification in preventing autograft failure requiring reoperation.

METHODS

From 1994 to 2005, 46 children and young adults with a mean age of 12.9 +/- 4.9 years (range, 14 months to 21 years) underwent a Ross procedure; 19 of 46 patients had prior aortic valve surgery. Neoaortic valve function and need for reintervention were compared between patients who had a Ross procedure without annuloplasty (n = 20) and those who had an annular reduction prior to the autograft anastomosis (n = 26).

RESULTS

There were no early or late deaths during a mean follow-up of 65 +/- 36 months. Mean hospital stay was 6.6 +/- 2.9 days. Two patients required early intervention (eight days) for significant neoaortic regurgitation; one patient required repair of a left ventricular outflow tract pseudoaneurysm a month after emergent Ross procedure for endocarditis, and one patient required replacement of a stenotic homograft at five years. Five patients (13%) required autograft repair (n = 3) or replacement (n = 2) for progressive neoaortic regurgitation, two of the 26 patients had reduction annuloplasty (8%), and three of the 20 patients did not (15%) (p = 0.6). There was a similar incidence of neo-sinus of Valsalva dilatation 37 mm or greater in patients with (53%) and without (36%) annuloplasty (p = 0.5).

CONCLUSIONS

The Ross procedure remains an excellent option for valve replacement in children and young adults given the alternatives and can be performed with very low mortality. However, in this series of Ross operations in children, routine use of aortic annuloplasty failed to prevent neoaortic regurgitation requiring reoperation.

Autografts, homografts, and xenografts: overview on stentless aortic valve surgery

Stentless valves, either human (autografts, homografts) or animal (porcine xenografts), were historically among the first substitutes to be used to replace the diseased aortic valve. Forty years after those pioneering days and 15 years after revival of such valves, stentless grafts have become a mainstay in aortic surgery. Although limitations associated with the use of autografts, homografts and xenografts remain, stentless valves have profoundly improved quality of life after aortic valve/root replacement. In addition, stentless surgery has greatly advanced the understanding of aortic root anatomy, physiology and pathology among surgeons.

Subcoronary Ross Procedure in Patients With Active Endocarditis

BACKGROUND

The Ross procedure has gained increasing interest as an attractive alternative to a prosthetic aortic valve substitute within the last decade. Because of a probably better resistance to infection as one of its advantages, the pulmonary autograft is theoretically preferable for active endocarditis.

METHODS

Between June 1994 and July 2003, the Ross procedure was performed using the subcoronary and inclusion technique in 296 patients (231 male, 65 female). Twenty patients had an active endocarditis of the aortic valve at the time of operation. A bicuspid valve was present in 10 patients. One patient had previous aortic valve surgery. Clinical and echocardiographic follow-up was complete.

RESULTS

Early mortality was 1, late mortality was 0. There were no recurrence of endocarditis and no neurologic events during the mean follow-up of 47.3 +/- 28.6 months. All patients were in New York Heart Association class I. Mean and maximum pressure gradient across the autograft was 3.5 +/- 2.0 and 6.5 +/- 3.4, respectively, with no autograft insufficiency in 15, 1+ in 4. Comparing postoperative with the last investigations, there were no significant changes of pressure gradients or grade of regurgitation. Mean and maximum homograft pressure gradients were 7.9 +/- 3.7 and 16.2 +/- 8.1 mm Hg, respectively, at last investigation; most patients had no or mild homograft regurgitation (0+, n = 13; 1+, n = 5; 2+, n = 1).

CONCLUSIONS

Native valve endocarditis can be treated with excellent results using the Ross procedure with the subcoronary and inclusion technique, with low mortality and morbidity rates and a very low recurrence rate of endocarditis.

Long-term outcomes in valve replacement surgery for infective endocarditis

BACKGROUND

Infective endocarditis is associated with a high rate of long-term mortality. Patients with a history of intravenous drug use (IVDU) are at increased risk for infective endocarditis. However, few studies have reported results of surgical treatment on this population. We present 19.5 years of experience with surgically treated patients with infective endocarditis.

METHODS

A retrospective study of all cardiac surgeries with a diagnosis of infective endocarditis at a single institution from 1986 to 2005 was performed. Logistic stepwise regression with an end point of operative mortality was done. Variables were age, gender, race, history of drug use, previous valve surgery, and previous valve replacement. Perioperative and outcome variables were compared between IVDU and non-IVDU populations.

RESULTS

The IVDU population required surgery at a younger age (39 +/- 9 years versus 54 +/- 15 years; p < 0.001). Overall operative mortality was 12% (41/346). The perioperative complication rate was similar for both groups. When adjusted for age, the two groups had similar long-term survival (p = 0.78). Kaplan-Meier estimator showed that survival at 10 and 15 years was 66% and 54% for IVDU and 56% and 42% for non-IVDU (number at risk, 19, 11, and 61, 28, respectively; p = 0.137). Reoperation for recurrent infective endocarditis was necessary in 9 (17%) of 52 of the IVDU group versus 14 (5%) of 270 of the non-IVDU group (p = 0.03).

CONCLUSIONS

Patients with a history of IVDU required reoperation for recurrent infective endocarditis at a significantly higher rate than the non-IVDU patients. Long-term survival was similar between the younger IVDU population and the older non-IVDU population. Anticipated life span is one of many factors when considering prosthetic valve choice in this population.

Freestyle stentless bioprosthesis for active aortic infectious endocarditis with undetermined causative organism

A 52-year-old woman developed congestive heart failure and was diagnosed with aortic regurgitation with approximately 20 mm of vegetation located on the noncoronary cusp of the aortic valve. The patient had undergone tooth extraction 3 months earlier, and various antibiotics had been given in the treatment of refractory high fever for 1 month. The damage to the aortic valve extended to the fibrous trigone near the mitral valve, and aggressive debridement of necrotic and infected tissue was done. The excised defect was repaired and reinforced with a pericardial patch, and the Freestyle stentless bioprosthesis was implanted using the full-root technique. Although the causative organism was never isolated, recurrent endocarditis has not occurred during 3 years of follow-up. The Freestyle stentless bioprosthesis was useful in the management of active aortic infectious endocarditis with undetermined causative organism for the prevention of recurrent endocarditis in the early postoperative period.

Active infectious endocarditis: postoperative outcome

OBJECTIVE

Many changes have occurred in the natural history and the management of active infectious endocarditis (AIE) in recent years. Therefore, the records of patients admitted in a tertiary care specialized hospital presenting with the Duke criteria were reviewed.

METHODS

Adults operated on to treat AIE were included during a 3-year period. Patients presenting with AIE associated with a pacemaker were not included. Bacteriologic investigations included blood cultures, intraoperative samplings (including polymerase chain reaction), and serologies. Clinical and bacteriologic factors associated with hospital mortality were studied by univariate regression analysis (p < 0.05).

RESULTS

Ninety-eight of 164 patients (60%) admitted with the diagnosis of AIE underwent valvular surgery. The duration between the beginning of AIE and surgery was 23 +/- 16 (mean +/- standard deviation) days. Only 45 patients had a previous history of valvular disease. Seventy-two patients presented with aortic and 41 with mitral valve AIE. Fifty suffered from embolic events. Streptococcus species were responsible in 64 cases (23 were Streptococcus bovis) and Staphylococcus species in 24 cases. Death occurred postoperatively in 19 patients. The factors associated with fatal outcome were preoperative hemodynamic instability, age, Parsonnet and Simplified Acute Physiology Score II scores, diabetes mellitus, preexisting valvulopathy, antiarrhythmic treatment, hypoalbuminemia, renal dysfunction, duration of extracorporeal circulation, and red cell allogeneic transfusions. The type of bacteria did not influence mortality. The mean intensive care unit and hospital stays were 10 and 39 days, respectively. Eleven patients suffered from neurologic sequelae; 2 years later, 2 of them presented with severe deficit and 1 had died.

CONCLUSIONS

AIE necessitating cardiac surgery should be considered as a severe and resource-consuming disease.

Aortic Homograft: A Suitable Substitute for Aortic Valve Replacement

BACKGROUND

The aim of our study is to assess the results of aortic valve replacement with the aortic homograft.

METHODS

From January 1994 through September 2003, 154 patients with aortic valve disease (rheumatic = 118, nonrheumatic = 36), and a mean age of 28.8 +/- 18.2 years, underwent aortic valve replacement with an aortic homograft by the scalloped subcoronary (n = 110) or root replacement (n = 38) technique, or as a valved homograft conduit (n = 6). Associated procedures included mitral valve repair (n=30), open mitral commissurotomy (n = 22), tricuspid valve repair (n = 8), coronary artery bypass grafting (n = 6), and atrial septal defect closure (n = 1).

RESULTS

Early mortality was 7.8% (12 patients). Mean follow-up was 62 +/- 33.4 months (4 to 127 months; median, 68.5 months). One hundred and twenty-four survivors (87.3%) had no or trivial to mild aortic regurgitation. A total of six patients required reoperation for homograft dysfunction alone (n = 4), infective endocarditis (n = 1), or failure of mitral valve repair (n = 1). There were four late deaths. Actuarial and reoperation-free survival at the median follow-up were 92.2 +/- 2.2% and 95.8 +/- 1.9%, respectively. Freedom from significant aortic stenosis or regurgitation was 86.1 +/- 3.2%.

CONCLUSIONS

Aortic valve replacement with an aortic homograft can be performed with acceptable early and late mortality and provides satisfactory midterm results. We did not note any difference in homograft dysfunction and reoperation with the use of either scalloped subcoronary or root replacement technique.

Prosthetic valve endocarditis

Prosthetic valve endocarditis is a catastrophic complication of cardiac valve replacement, associated with high mortality rates. Medical treatment is effective in a few instances of endocarditis involving the leaflets alone in bioprostheses. However, accurate diagnosis, better myocardial protection, and improved surgical strategies have led to better survival in patients undergoing surgery after failed conservative therapy. This comprehensive review addresses various issues involved in the management of this complication.

Factors influencing late allograft valve failure

Allograft valves are a valuable valve replacement substitute in the surgical management of heart valve disease. It remains the valve substitute of choice in the reconstruction of the right ventricular outflow tract in children with congenital heart disease and in the Ross procedure. However, its durability remains suboptimal, particularly in children. This article reviews the mechanisms and factors implicated in late allograft dysfunction, with a focus on the evidence for an immunological cause for allograft valve failure. Unravelling the mechanisms of allograft valve failure may allow modification of the allograft to improve its long-term durability.