Recurrent aortic root homograft endocarditis related to indwelling hemodialysis catheters

Abstract

Infective endocarditis and abscess of the valve ring are unusual complications after prosthetic surgery of the aortic valve and root. We report a case of recurrent and fatal endocarditis with abscess of an aortic root homograft. Recurrent bacteremia related to indwelling hemodialysis catheters predisposed the patient to this complication. A 32-year-old man had been receiving peritoneal dialysis for chronic renal failure since 1993. Hemodialysis using an internal jugular catheter was started in August 1998 because of repeated peritonitis. In September 1998, he developed methicillin-sensitive Staphylococcus aureus (MSSA) infective endocarditis, acute aortic regurgitation, and aortic root abscess, which were treated with aortic valve and root homograft replacement, including the anterior mitral leaflet and ascending aorta up to the great vessels. Naficillin, rifampin, and gentamicin were administered for 6 weeks. The endocarditis recurred 2 months later with vegetations of the aortic valve, and the patient was again treated with a 6-week course of naficillin, gentamicin, and rifampin. A right-side internal jugular dialysis access catheter was inserted after the bacteremia resolved. Later, in April 1999, he had another episode of MSSA bacteremia that was treated with the same antibiotics. The patient came to us in August 1999 with a 1-week history of weakness followed by 2 days of fever, chills, and diarrhea. He was lethargic but responded to questions. His pulse rate was 130 beats per minute; blood pressure, 115/70 mm Hg; respirations, 26 breaths per minute; and temperature, 39.9°C. An ejection systolic murmur and an early diastolic murmur of 2/6 intensity were noted over the left sternal border. Laboratory tests showed a total leukocyte count of 30,900/μL (neutrophils 50%, bands 41%, lymphocytes 3%, monocytes 6%), hemoglobin 8.9 g/dL, blood urea nitrogen 65 mg/dL, creatinine 14 mg/dL, and troponin I 4.2 ng/mL (normal range 0 to 1.5 ng/mL). The initial electrocardiogram showed a first-degree atrioventricular block. A second electrocardiogram 6 hours later showed a second-degree type 1 atrioventricular block. Transesophageal echocardiography revealed vegetations of the aortic, mitral, and tricuspid valves, aortic homograft abscess, and regurgitations of the aortic, mitral, and tricuspid valves. Blood cultures and cultures of the tip of the dialysis catheter grew MSSA. The patient was treated with vancomycin, gentamicin, and rifampin. He was considered a poor risk for any surgery, and he wished not to be resuscitated. He died 3 days later, after his condition progressed to complete heart block. Aortic valve endocarditis with aortic root abscess and significant valvular damage is increasingly being managed by using cryopreserved homograft conduits. Early recurrence of endocarditis is rare after such procedures (1McGiffin D.C. Kirklin J.K. The impact of aortic valve homografts on the treatment of aortic prosthetic valve endocarditis.Semin Thorac Cardiovasc Surg. 1995; 7: 25-31PubMed Google Scholar). Excellent survival, with a 5-year endocarditis recurrence rate as low as 3%, has been reported once the immediate postoperative period is over (2Niwaya K. Knott-Craig C.J. Santangelo K. et al.Advantage of autograft and homograft valve replacement for complex aortic valve endocarditis.Ann Thorac Surg. 1999; 67: 1603-1608Abstract Full Text Full Text PDF PubMed Scopus (104) Google Scholar). Intravenous drug use and nosocomial bacteremia are traditional risk factors for endocarditis (3Steckelberg J.M. Wilson W.R. Risk factors for infective endocarditis.Infect Dis Clin North Am. 1993; 7: 9-19PubMed Google Scholar). Hemodialysis catheters are emerging as important sources of bacteremia that might lead to endocarditis (4Hoen B. Paul-Dauphin A. Hestin D. Kessler M. EPIBACDIAL a multicentric prospective study of risk factors for bacteremia in chronic hemodialysis patients.J Am Soc Nephrol. 1998; 9: 869-876PubMed Google Scholar, 5Saad T.F. Bacteremia associated with tunneled, cuffed hemodialysis catheters.Am J Kidney Dis. 1999; 34: 1114-1124Abstract Full Text Full Text PDF PubMed Scopus (268) Google Scholar). Endocarditis recurred in our patient as a consequence of recurrent bacteremia from an infected vascular access catheter for hemodialysis. Indwelling hemodialysis catheters should be considered risk factors for developing infective endocarditis.