Asian Cardiovasc Thorac Ann 2001;9:132-134
© 2001 Asia Publishing EXchange Pte Ltd
Tricuspid Endocarditis and Paradoxical Embolism
Michael Caleb, MBBS,
Sriram Shankar, MBBS,
Thirugnanam Agasthian, MBBS
Department of Cardiothoracic Surgery
National Heart Centre
Singapore, Republic of Singapore
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For reprint information contact: Michael Caleb, MBBS Tel: 65 436 7598 Fax: 65 224 3632 email: michael_caleb{at}nhc.com.sg Department of Cardiothoracic Surgery, National Heart Centre, 17 Third Hospital Avenue, Mistri Wing, Singapore 168752, Republic of Singapore.
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Abstract
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A 32-year-old male heroin addict presented with pneumonia, septic shock, and disseminated intravascular coagulopathy. He was found to have tricuspid endocarditis with pulmonary and splenic septic emboli. A patent foramen ovale was detected during surgery, which was closed, vegetation was excised, and the tricuspid valve was repaired with autologous pericardium. Recovery was rapid.
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Introduction
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Intravenous drug addiction remains a problem in many Asian countries. Tricuspid endocarditis as a consequence of drug addiction can usually be treated effectively with appropriate antibiotics. When these fail, surgery is often indicated to eradicate persistent or intractable sepsis or severe right heart failure, and to prevent further distal embolization. The type of surgery chosen to achieve these goals is debatable and often guided by the premorbid cardiac status and the known predisposition to recurrent addiction.
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Case Report
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A cachectic 32-year-old man, a known intravenous heroin abuser for 10 years, presented with pneumonia of 2 weeks' duration, culminating in septic shock and disseminated intravascular coagulopathy. An urgent echocardiogram revealed vegetations on the anterior leaflet of the tricuspid valve with mild regurgitation. There was no report of an intracardiac shunt. With prolonged immobilization, he developed extensive proximal deep venous thrombosis of the right lower limb. This was treated with subcutaneous enoxaparin. One week later, a computed tomographic scan revealed cavitary lesions of the right lung and multiple splenic infarcts with microabscesses. Despite antibiotics against methicillin-sensitive Staphylococcus aureus, spiking fever continued. On 100% oxygen by face mask, this young man's oxygen saturation was only 86%. As he remained breathless, a pulmonary angiogram was per-formed to rule out pulmonary embolism. Contrast injected into the right atrium to avoid dislodging vegetations on the tricuspid valve, demonstrated clear bilateral main pulmonary arteries. A Simon nitinol inferior vena caval filter (Bard Peripheral Technologies, Covington, GA, USA) was inserted concurrently. He was referred to our care for persistent sepsis from infective endocarditis and infective pulmonary cavitary lesions. At this time, we were hesitant to operate because of his poor general state and the unexplained persistent hypoxemia. A ventilationperfusion scan demonstrated a high probability of pulmonary embolism involving the right middle zone and the left basal zone, with matched defects consistent with infective changes involving the right apical, right basal, and left upper and middle zones. A second echocardiogram revealed a large 2-cm anterior leaflet vegetation with full-blown tricuspid regurgitation. The pulmonary artery pressure was calculated to be normal. Blood culture revealed coagulase-negative staphylococci so the antibiotic regime was adjusted accordingly. Within 10 days of treatment, the fever settled and the leukocyte count fell from 24,000 x 106/L to 12,000 x 106/L. The infective lung fields were resolving although hypoxemia remained. Two days later, fever recurred and no other source of infection could be traced. Because of recurrent sepsis and persistent hypoxemia, surgery was offered.
An intraoperative transesophageal echocardiogram revealed no left-sided endocarditis or intracardiac shunt. The operative approach was through a median sternotomy. The pulmonary artery was not tense to palpation. Cardiopulmonary bypass was established using bicaval cannulae with caval tapes for drainage. The aorta was crossclamped and cold blood cardioplegic hypothermic arrest was achieved. A 1.5-cm patent foramen ovale was found via a right atriotomy, confirming our suspicion of the cause of the paradoxical embolism and hypoxemia. The patent foramen ovale was closed by direct suture. There was a large 1.5-cm vegetation dangling on remnant tissue of an almost completely destroyed large anterior leaflet of the tricuspid valve. The septal leaflet was flimsy and thinned out. The posterior leaflet was small. The annulus and the interventricular septum were not involved. In view of the ongoing sepsis and the known predisposition to recurrent addiction, valve repair was decided. Because of the destroyed large anterior leaflet and flimsy septal leaflet, an imperfect result could be expected. However, this would be tolerated with the normal pulmonary arterial pressure. Earlier, a segment of autologous pericardium was harvested and prepared with 0.625% glutaraldehyde (10-minute soak and 15-minute rinse). This was fashioned into a new anterior leaflet segment with extensions as long strips to simulate chordae. This was sewn to the annulus using 5/0 monofilament suture and the extensions were attached appropriately to muscular trabeculae or papillary muscles. The commissure between the new anterior leaflet and the septal leaflet was partially closed off. No prosthetic valve or ring was inserted in view of the coagulase-negative staphylococci with its known adherence to prosthetic materials. After coming off bypass, transesophageal echocardiography revealed moderate to severe tricuspid regurgitation that was much less than preoperatively. As expected, the patient did remarkably well and was extubated the next day with good blood gases. His fever settled within the week and his leukocyte count returned to normal. One week later, 2-dimensional echocardiography still revealed moderately severe tricuspid regurgitation. Three weeks after surgery, the patient was ambulant with no signs of right heart failure. He is aware that a second procedure may be required should severe right heart failure ensue, but only if he remains off his drug habit.
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Discussion
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Tricuspid endocarditis is a known complication of intravenous drug abuse and its management involves an appropriate course of culture-directed antibiotics. Surgery is offered for recurrent or intractable sepsis. Other indications include persistent septic embolism or severe right heart failure. Large vegetations are more likely to be associated with antibiotic failure. An interesting feature of this case was the persistent hypoxemia in a young man whose pulmonary sepsis had been adequately treated by antibiotics, with resolving lesions. Systemic (splenic) embolism in a patient with right-sided endocarditis suggested an intracardiac shunt despite an inconclusive echocardiogram. Confirmation came at surgery and closure of the patent foramen ovale eliminated his hypoxemia. Persistent hypoxemia can result from a patent foramen ovale that remains undetected unless a contrast echo study is performed.1,2
The surgical options for an infected tricuspid valve include simple excision of the vegetation, valvectomy, tricuspid valve repair, or valve replacement.3–5 Valvectomy without some sort of reconstruction would result in full-blown regurgitation postoperatively. If the pulmonary pressure is normal (in most cases, the heart was previously normal), this may be tolerated for years. Valve replacement usually gives better long-term hemodynamic results when a repair is unlikely to be satisfactory, as in cases of large or multiple leaflet destruction, such as our patient. However, a large number of patients return to their drug habit, predisposing them to fatal prosthetic valve endocarditis. Many valve repair techniques have been described, including pericardial bridging, leaflet sliding plasty, bicuspidization, and basal chordae mobilization. But as leaflet destruction increases, severe residual regurgitation is likely, especially if the remaining leaflets are small or abnormal. An underlying principle of surgery is to avoid foreign material in an infected field. Thus, valve repair using autologous pericardium in the presence of normal pulmonary arterial pressures, is a reasonable compromise. This avoids full-blown regurgitation seen with valvectomy alone or the danger of residual or recurrent sepsis with prosthetic implants, especially with coagulase-negative staphylococci. This patient's recovery was rapid and remarkable as both hypoxemia and sepsis were eliminated with surgery.
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References
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Turek MA, Karovitch A, Aaron SD, Brais M. Persistent hypoxemia occurring as a complication of tricuspid valve endocarditis. J Am Soc Echocardiogr 2000;13:412–4.[Medline]
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Godart F, Rey C, Prat A, Vincentelli A, Chmait A, Francart C, et al. Atrial right-to-left shunting causing severe hypoxaemia despite normal right-sided pressures. Report of 11 consecutive cases corrected by percutaneous closure. Eur Heart J 2000;21:483–9.[Abstract/Free Full Text]
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Allen MD, Slachman F, Eddy AC, Cohen D, Otto CM, Pearlman AS. Tricuspid valve repair for tricuspid valve endocarditis: tricuspid valve "recycling". Ann Thorac Surg 1991;51:593–8.[Abstract]
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Yee ES, Khonsari S. Right-sided infective endocarditis: valvuloplasty, valvectomy or replacement. J Cardiovasc Surg (Torino) 1989;30:744–8.[Medline]
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Arbulu A, Holmes RJ, Asfaw I. Surgical treatment of intractable right-sided infective endocarditis in drug addicts: 25 years experience. J Heart Valve Dis 1993;2: 129–39.[Medline]
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Abstract
Introduction
