C Özbek, U Yetk?n, T Göktogan, N Postac?, M Yesil, A Gürbüz
brucella endocarditis, brucellosis, infective endocarditis, vegetation
C Özbek, U Yetk?n, T Göktogan, N Postac?, M Yesil, A Gürbüz. Echocardiographic Evaluation Of Mitral Valve. The Internet Journal of Thoracic and Cardiovascular Surgery. 2006 Volume 9 Number 2.
Brucellosis shows various clinical signs and can affect different organs. Although rare, endocarditis is important because it can be fatal.
A 43 years old livestock producer had rheumatismal severe aortic stenosis and moderate aortic insufficiency. He refused an aortic valve replacement. 3 months after admission he became infected with brucella organism and his mitral valve was affected. In this study we're presenting the results of transthoracic/esophageal echocardiography and our successful radical treatment.
Echocardiography is very important for diagnosis, follow-up and treatment plan and we think that antibiotic therapy and surgery combination is the most effective treatment option.
Brucellosis continues to be reported from the Mediterranean and Middle-East countries (1,2). 10 to 15% of the patients have complicated brucellosis (1). Although endocarditis is seen in less than 2% of the cases it is responsible from the half of the deaths due to brucellosis (3). We're presenting a case who had severe cardiac damages due toendocarditis and the damages were confirmed with echocardiographic controls.
Our patient was a 43 years old man with severe rheumatismal aortic valve stenosis and moderate aortic insufficiency and mild maladie mitral (mitral stenosis+insufficiency). He was admitted to an institute on August 2005 and didn't accept the aortic valve replacement (AVR) operation as recommendation (Figure 1-3).
His coronary angiography was normal at that time. His job was animal husbandry and he was hospitalized for 15 days due to Brucellosis diagnosis on November 2005.
The transthoracic echocardiography (TTE) which was performed in January 2006, showed that his mild mitral insufficiency progressed and a 19.4 x 21.5 mm vegetation developed at anterior mitral leaflet. Also, mitral maximum gradient secondary to mitral insufficiency increased to 18.4 mmHg from 11.8 mmHg (Figure 4).
Transesophagial echocardiography (TEE) showed a vegetation at anterior mitral leaflet and the increased mitral insufficiency (Figures 5 and 6).
After ending his triple medical therapy [doxycycline (200 mg/d), rifampin (600 mg/d), and ceftriaxone (2 g/d)], we took him to operation. We carefully performed median sternotomy and routine bicaval canulation with minimal manuplation. Arrest was achieved with moderate hypothermia 28°C, and incompressive retrograde isothermic potassiumed blood cardioplegy. Following aortotomy we explored; the nativ aortic valve was found severely calcific and leaflets had pleability disorder (Figure 7).
Smooth calcifications with few high density regions were interesting. There was a high degree calcification at the mitral valve, including all the anterolateral commissure and infiltrating the endocard and myocard. Subvalvular appareil was normal. There were widespread, calcific and vegetative images beginning from anterolateral commissure and extending medially to both leaflets (Figure 8).
We performed a MVR with 29 no Sorin bileaflet mechanical valve + AVR (23 no Sorin) on February 2005. No additional problem was seen postoperatively and he was discharged on 6th day with surgical cure and outpatient clinic follow was recommended.
He is still symptom-free and the valve functions are good.
Brucellosis is caused by Brucella organisms and acquired by direct contact of infected animals or indirectly by ingesting unpasteurized milk and products of milk (1,2). Our patient was infected directly because he was a livestock producer.
Aglutination (Wright) test is a very important serological test method for diagnosis. Many cases have titers of 1:320 or higher (4). Our case was diagnosed by history, occupation, positive serology and his echocardiography showed a big vegetation on the mitral valve.
Echocardiography is very important to determine the treatment protocol,and the morbidity and mortality rates in all infective endocarditis, including Brucellosis(2,5). It is a cheap, easy to use, noninvasive and a reproducible method. The most important point in echocardiographic evaluation is combination of TTE and TEE. Most frequently, vegetation is searched in echocardiography and usually it causes insufficiency due to valve damage. If they're big enough and unstabile, they can be determined easily by TTE. On native valves, the imaging rate is 25% for vegetations smaller than 5 mm and 70% fort he ones larger than 6 mm (6). TEE's sensitivity and specifity are higher for small vegetations (<2 mm) and for determining the perivalvular extention of the infection (7). Native valve endocarditis studies showed a sensitivity of 46% and specifity of 95% for TTE.These rates were 93% and 96% for TEE (6,8).
Microbes such as Staph. Aureus, Serratia sp, Pseudomonas sp and Candida sp, Brucella sp also injure the tissues (1,5). Infective endocarditis injures the valve and causes insufficiency flow (9). 1 to 2 degrees insufficiency flow is negligable in normal valves and severe increase is an important symptom for diagnosing infective endocarditis. If there is important valve insufficiency new flow records of severe aort or mitral valve insufficiency is accepted as major endocaedial symptom as in our case.
Embolization risk due to vegetation is in close relation with mortality and morbidity. Clinical symptom rate is 10-50% for vegetations (10). Native mitral valve infective endocarditis has a 5 times higher embolization risk than the aortic valve, so anterior mitral valve vegetations (particularly if larger than 15 mm) or recurrent embolies are indications for surgery (10,11).
Vegetations are on ventricular side in mitral stenosis and on atrial side in mitral insufficiency (12).
Medical treatment alone is unsuccessful for Brucella endocarditis and surgery is necessary (1,13). The most effective option is antibiotic and surgery combination. Two main approaches of surgery are;controlling the infection by debriding the infected and necrotic tissue and reconstructing the cardiac morphology by repairing or replacing the damaged valves. Although homografts are ideal due to low infection risk,it is hard to produce them (13). Combination of antibiotic therapy and mechanical valve replacement has a satisfactory result. Early and late reinfection incidence of mechanical valve replacement can be compared with the results and survival expectations of homografts and tissue valves (14).
Mechanical valve replacement was used for Brucella endocarditis in a study with 6 cases and there wasn't any mortality and late recurrence during 47 weeks of follow-up (15). We used surgical debridment and mechanical valve replacement and add doxycicline+rifampin for 8 weeks.
In conclusion; brucella endocarditis is a rare infective endocarditis form and its diagnostic rate and surgical therapy practices increased due to availability of echocardiography. Brucella endocarditis does not show remission and has a high mortality if not treated. It must be known that surgical approach increases the quality of life for a long period in this type endocarditis.
Doç. Dr. Cengiz ÖZBEK Şair EŞref Bulvarı,No:66/1,İdil Apt. 35220, Alsancak / İZMİR / TURKEY Tel: +90 532 2870780 e-mail: email@example.com