A 38 year old man with endocarditis of the prosthetic mitral valve
(presented to another hospital)
A 38 year old man presented with low grade fever and acute onset right leg numbness and weakness, 2 months following aortic valve replacement (bioprosthetic valve) and permanent pacemaker implantation for bicuspid aortic valve / aortic stenosis / complete heart block. Bilateral leg emboli in the anterior and posterior tibial arteries were diagnosed. An urgent embolectomy was performed. Tissue sections from the extracted emboli revealed branching septate hyphae resembling aspergillus on fungal stains. Aspergillus species was isolated from the fungal cultures of the embolectomy specimen. A transthoracic echocardiogram revealed a large aortic valve vegetation. Oral voriconazole was started, however fever persisted and followup echocardiography revealed a persisting vegetation 3 weeks later. The patient was taken up for cardiac surgery and a vegetatectomy was performed (while leaving the prosthetic valve / permanent pacemaker in situ). Aspergillus species was isolated from cultures of the vegetation.The patient's symptoms improved after surgery and voriconazole was continued for 3 more weeks.
One week after stopping voriconazole the patient developed worsening backache associated with high grade fevers. A CT of the spine revealed lumbar vertebral enhancing hypodensities. A PET scan revealed uptake in the lumbar and cervical vertebrae, along with few foci of uptake in the occipital lobe along with uptake in the soft tissue of the both thighs. Fungal stains of the soft tissue masses in the thigh revealed fungal hyphae. Fungal cultures were negative. A transesophageal echocardiogram revealed a large vegetation on the aortic valve. Rifampicin based antituberculous therapy was empirically.
The case report highlights several aspects:
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The unusual occurrence of fungal endocarditis after cardiac surgery (probably caused by aspergillus spores in the ambient air during the intraoperative period)
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Fungal endocarditis requires early cardiac surgery. Also it is very important to remove foreign surfaces such as prosthetic valves and pacemaker leads to avoid recurrence.
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Voriconazole is the drug of choice. Combination antifungal therapy (eg echinocandin + voriconazle) needs to be considered for serious aspergillus infections.
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Prolonged therapy is required for fungal endocarditis (even lifelong suppressive therapy)
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Drug interactions between cytochrome P450 inducing drugs such as rifampcin and azole antifungals. Therapeutic drug monitoring of voriconazole is crucial in such cases.
See similar case in CID 2005 Pubmed
Review of world literature Pubmed
Prosthetic valve endocarditis of the aortic valve caused by Aspergillus species with bilateral lower limb emboli and dissemination of aspergillus infection
Sepsis after cardiac surgery in a 2 year old boy
A 2 year old boy underwent repair of tetralogy of Fallot. Post operatively the chest was left open (delayed sternal closure). Post operative course was marked by hypotension requiring ionotrope infusion at high doses. On third day after surgery, the sternal wound was closed; however a emergency reexploration procedure was done after a few hours (owing to deteriorating hemodynamics and worsening oxygenation) and the sternal wound closure was deferred.
Owing to deteriorating hemodynamic status and leucocytosis, broad spectrum antibiotics were initiated. However blood cultures 48 hours after clinical deterioration were negative for bacterial or fungal pathogens. Echinocandin therapy was initiated based on a suspicion of culture negative candida sepsis.
Tissue sent from sternal surgical site grew Aspergillus species on second day. With continuing hemodynamic instability, the patient was initiated on voriconazole and caspofungin. However the patient continued to deteriorate and died on day 10 after surgery.
Mediastinitis after delayed sternal closure complicates less than 10% of such cases. Aspergillus mediastinitis is rare occurrence probably due to ambient Aspergillus spores during the long chest open period. High efficiency particulate filters in units handling such patients may have a role in prevention of these infections
Mediastinitis due to Aspergillus species in a case of delayed sternal closure after cardiac surgery