Prosthetic aortic valve: A bone in the system (original) (raw)

Native and Prosthetic Aortic Valve Endocarditis

Aortic Valve, 2011

The epidemiological profile of IE has changed substantially over the last few years. In industrialized countries, the typical pattern of IE is now an elderly patient with a degenerative heart valve disease or with a prosthetic valve or an intracardiac device such as a pacemaker or defibrillator leads. Major changes have occurred in the mode of acquisition of IE and in its microbiological profile (Thuny et al, 2010). Significant geographical variations have been shown. The highest increase in the rate of staphylococcal IE has been reported in the USA, where chronic hemodialysis, diabetes mellitus, and intravascular devices are the three major factors associated with the development of Staphylococcus aureus (S. aureus) endocarditis. In other countries, the main predisposing factor for S. aureus IE may be intravenous drug abuse (Habib et al, 2009). 1.4 Incidence The incidence of IE ranges from one country to another within 3-10 episodes/100,000 person-years. This may reflect methodological differences between surveys rather than true variation. Of note, in these surveys, the incidence of IE was very low in young patients but increased dramatically with age-the peak incidence was 14.5 episodes/100,000 personyears in patients between 70 and 80 years old. In all epidemiological studies of IE, the male:female ratio is 2:1, although why there is a higher proportion of men is poorly understood. Furthermore, female patients may have a worse prognosis and undergo valve surgery less frequently than their male counterparts (Habib et al, 2009). Patients with prosthetic aortic valves are reported to have an incidence of PVE of 0.3 to 1.2 episodes per 100 patients/year, and approximately 1.4% of patients undergoing aortic valve replacement develop PVE during the first postoperative year. 1.5 Types of infective endocarditis IE should be regarded as a set of clinical situations that are sometimes very different from each other. In an attempt to avoid overlap, the following four categories of IE must be separated according to the site of infection and the presence or absence of intracardiac foreign material: left-sided native valve IE, left-sided prosthetic valve IE, right-sided IE, and device-related IE (the latter includes IE developing on pacemaker or defibrillator leads with or without associated valve involvement). With regard to acquisition, the following situations can be identified: community-acquired IE, healthcare-associated IE (nosocomial and non-nosocomial), and IE in intravenous drug abusers (IVDAs) (Habib et al, 2009). 1.6 Microbiology The microbiology of IE of the aortic valve depends on whether the valve is native or prosthetic, and whether the infection is hospital-or community-acquired. According to microbiological findings, the following categories are proposed: 1. IE with positive blood cultures. This is the most important category, representing 85% of all IE. Causative microorganisms are most often staphylococci, streptococci, and enterococci (Murdoch et al, 2009). a. IE due to streptococci and enterococci. Oral (formerly viridans) streptococci form a mixed group of microorganisms, which includes species such as S. sanguis, S. mitis, S. salivarius, S. mutans, and Gemella www.intechopen.com Native and Prosthetic Aortic Valve Endocarditis 95 morbillorum. Microorganisms of this group are almost always susceptible to penicillin. Members of the S. milleri or S. anginosus group (S. anginosus, S. intermedius, and S. constellatus) must be distinguished since they tend to form abscesses and cause hematogenously disseminated infections, that often require a longer duration of antibiotic treatment. Likewise, nutritionally variant "defective" streptococci, recently reclassified into other species (Abiotrophia and Granulicatella), should also be distinguished since they are often tolerant to penicillin [minimal bactericidal concentration (MBC) much higher than the minimal inhibitory concentration (MIC)]. Group D streptococci form the Streptococcus bovis/ Streptococcus equinus complex, including commensal species of the human intestinal tract, and were until recently gathered under the name of Streptococcus bovis. They, like oral streptococci, are usually sensitive to penicillin. Among enterococci, E. faecalis, E. faecium, and, to a lesser extent, E. durans, are the three species that cause IE. b. Staphylococcal IE. Traditionally, native valve staphylococcal IE is due to S. aureus, which is most often susceptible to oxacillin, at least in community-acquired IE. In contrast, staphylococcal prosthetic valve IE is more frequently due to coagulase-negative staphylococci (CNS) with oxacillin resistance. However, in a recent study of 1779 cases of IE collected prospectively in 16 countries, S. aureus was the most frequent cause, not only of IE, but also of prosthetic valve IE (Fowler et al, 2005). Conversely, CNS can also cause native valve IE (Chu et al, 2004, 2008) especially S. lugdunensis, which frequently has an aggressive clinical course. 2. IE with negative blood cultures because of prior antibiotic treatment. This situation arises in patients who received antibiotics for unexplained fever before any blood cultures were done and in whom the diagnosis of IE was not considered; usually the diagnosis is eventually considered in the face of relapsing febrile episodes following antibiotic discontinuation. Blood cultures may remain negative for many days after antibiotic cesation, and causative organisms are most often oral streptococci or CNS. 3. IE frequently associated with negative blood cultures. They are usually due to fastidious organisms such as nutritionally variant streptococci, fastidious Gram-negative bacilli of the HACEK group (H. parainfluenzae, H. aphrophilus, H. paraphrophilus, H. influenzae, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae, and K. denitrificans), Brucella, and fungi. 4. IE associated with constantly negative blood cultures. They are caused by intracellular bacteria such as Coxiella burnetii, Bartonella, Chlamydia, and, as recently demonstrated, Tropheryma whipplei, the agent of Whipple's disease (Richardson et al, 2003). Overall, these account for up to 5% of all IE. Diagnosis in such cases relies on serological testing, cell culture, or gene amplification (Habib et al, 2009).

Case of prosthetic valve endocarditis with osteomyelitis associated with disregarded skin infection

Background: Prosthetic valve endocarditis (PVE) is a serious condition associated with high mortality rate. The causes of PVE vary from surgical procedure to superficial skin infection. Sometimes it is difficult to identify latent infections in the body and recognize them as the true causes of PVE. We describe here a case of PVE complicated by osteomyelitis that was hematogenously disseminated from a disregarded infected skin tumor on the head. Methods: A 73-year-old man who underwent aortic valve replacement developed prosthetic valve endocarditis complicated by osteomyelitis that was disseminated from an infected skin tumor on the head. During the follow-up after the first operation, neither a small skin mass on the head nor lower back pain had been considered manifestations of infection. With progressive pain and fever, however, the patient was referred back to our hospital for further examination; vegetation and paravalvular leakage around the aortic valve and lumbar osteomyelitis was detected. Results: A Staphylococcus aureus blood culture confirmed the diagnosis of prosthetic valve endocarditis associated with osteomyelitis, originating from the infected skin tumor. Re-operation was performed. The affected aortic valve was excised through a transverse aortotomy, revealing a deep annular abscess and partial valvular dehiscence. After the abscess was debrided completely, the damaged annulus was reconstructed with an autologous pericardium. For the valve implantation, pledgeted 2-0 mattress sutures were threaded through the aortic root from the outside, considering the potential fragility of the annulus. With multidisciplinary treatment, re-aortic valve replacement by cardiac surgeons, removal of the skin tumor by dermatologists, and intensive antibiotic therapy for osteomyelitis by orthopedists, the patient recovered. Conclusion: Valve replacement patients are vulnerable to external infective agents, hence awareness should be directed towards the potential threats. Keywords: Endocarditis, prosthesis, infection, co-morbidity, reoperation

Prosthetic valve endocarditis

BMJ, 1983

During 1965 to 1982, 32 episodes of infective endocarditis on prosthetic valves in 30 patients were treated at this hospital. In early endocarditis (presenting within four months of operation) staphylococci were the organisms most commonly responsible. Early endocarditis appears to be declining in incidence and is largely preventable; sternal sepsis was the main predisposing factor, requiring urgent and effective treatment. Streptococci were the most common organisms in late onset disease, but as with natural valve endocarditis a wide range of organisms was responsible. All but one of the patients with early onset disease were treated conservatively, but mortality was high; prompt surgical replacement of infected prostheses is probably indicated in such patients. Medical management was effective in most patients with late onset disease, and for them early surgical intervention may not be justified.

EARLY ONSET STREPTOMYCES ENDOCARDITIS OF A PROSTHETIC AORTIC VALVE

A 66-year old man from Australia underwent uneventful elective replacement of a heavily calcified severely stenotic aortic valve (AVR) with a 22 mm Medtronic-Hall valve. Six weeks later, the patient was readmitted because of progressively worsening effort dyspnea, fever and mild anaemia. Investigations confirmed the clinical diagnosis of pulmonary oedema and a moderate periprosthetic aortic regurgitation. The pulmonary oedema was managed conservatively and a redo AVR with a second 22 mm Medtronic-Hall valve was performed. A soft area in the aortic annulus below the orifice of the right coronary artery was suspicious of infective endocarditis. The bacteriological study revealed an infection with rare bacteria of Streptomyces species. The patient received intensive antibiotic therapy over 6-week period of hospitalization and the aortic regurgitation disappeared one week postoperatively.

Viridans streptococcal (Streptococcus mitis) biosynthetic aortic prosthetic valve endocarditis (PVE) complicated by complete heart block and paravalvular abscess

Heart & Lung: The Journal of Acute and Critical Care, 2012

Prosthetic valve endocarditis (PVE) may be classified clinically as early (<60 days) or late (>60 days) post-valve replacement PVE. The pathogens of early versus late PVE differ in type and virulence. Early PVE pathogens are virulent, for example, Pseudomonas aeruginosa and Staphylococcus aureus. Late PVE pathogens resemble those of subacute bacterial endocarditis and are due to relatively avirulent and noninvasive organisms, for example, viridans streptococci. Viridans streptococci vary in their invasiveness and abscess potential. Myocardial abscess and complete heart block are rare complications of late PVE due to viridans streptococci. We present an unusual case of Streptococcus mitis late aortic PVE complicated by aortic root abscess, myocardial abscess, and complete heart block.

Prosthetic Valve Endocarditis after Transcatheter Aortic Valve Implantation Complicated by Paravalvular Abscess and Treated by Pericardial Patches and Sutureless Valve Replacement

Heart Surgery Forum, 2019

Background: Endocarditis is a rare complication of transcatheter aortic valve implantation (TAVI), with an estimated 1-year incidence of 0.50% [Circulation 2015]. However, ensuing consequences are often dire, and its surgical treatment poses unique problems, due to the frequent underlying frailty of TAVI recipients. Case Report: We report the case of an 84-year-old woman, who developed Staphylococcus aureus prosthetic valve endocarditis (PVE) 7 days after transfemoral TAVI (ACU-RATE neo™, Boston Scientific or Symetis, further complicated by an aortic annular abscess with fistulization into the right atrium. The patient underwent successful operative aortic annulus repair, using pericardial patches, and aortic valve replacement with a sutureless Perceval S bioprosthesis (LivaNova). Conclusion: Our case documents the treatment of an active fistulizing Symetis ACURATE neo ™ prosthetic aortic valve endocarditis by using a sutureless LivaNova Perceval S prosthesis with satisfying hemodynamic results and an encouraging 1-year outcome, further corroborating its usefulness in such circumstances.

Rare cause of complicated prosthetic valve endocarditis

Indian Journal of Thoracic and Cardiovascular Surgery, 2017

A 29-year-old gentleman, employed in an animal farm, presented with a 6-month history of chronic fever, anorexia, and malaise. He had undergone aortic valve replacement with mechanical prosthesis for severe aortic stenosis due to bicuspid aortic valve at the age of 25. Clinical examination showed a normal jugular pulse, absence of cardiomegaly, normal prosthetic valve clicks, grade 3 ejection systolic murmur in the right second parasternal space, and non-tender hepatosplenomegaly. Labortory examination showed hemoglobin – 15.9 g/dl and a total count of 4900 cells/mm with a differential count of 49% polymorphs and 48% lymphocytes. Electrocardiogram showed a normal sinus rhythm with a PR interval of 150 ms. Echocardiography, transthoracic (Fig. 1a, Video 1), transesophageal (Fig. 1b, Video 2), and 3D (Fig. 1c, d, Video 3), revealed multiloculated aortic root abscess encircling the prosthetic valve. Blood culture grew Brucella melitensis in three consecutive samples and the same was co...

Early-onset prosthetic valve endocarditis definition revisited: Prospective study and literature review

International Journal of Infectious Diseases, 2017

To determine the annual incidence of prosthetic valve endocarditis (PVE) and to evaluate its current classification based on the epidemiological distribution of agents identified and their sensitivity profiles. Methods: Consecutive cases of PVE occurring within the first year of valve surgery during the period 1997-2014 were included in this prospective cohort study. Incidence, demographic, clinical, microbiological, and in-hospital mortality data of these PVE patients were recorded. Results: One hundred and seventy-two cases of PVE were included, and the global annual incidence of PVE was 1.7%. Most PVE cases occurred within 120 days after surgery (76.7%). After this period, there was a reduction in resistant microorganisms (64.4% vs. 32.3%, respectively; p = 0.007) and an increase in the incidence of Streptococcus spp (1.9% vs. 23.5%; p = 0.007). A literature review revealed 646 cases of PVE with an identified etiology, of which 264 (41%) were caused by coagulase-negative staphylococci and 43 (7%) by Streptococcus spp. This is in agreement with the current study findings. Conclusions: Most PVE cases occurred within 120 days after valve surgery, and the same etiological agents were identified in this period. The current cutoff level of 365 days for the classification of early-onset PVE should be revisited.