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Interact CardioVasc Thorac Surg 2009;9:357-359. doi:10.1510/icvts.2009.205427 © 2009 European Association of Cardio-Thoracic Surgery
Simultaneous Salmonella spp. endocarditis and mycotic abdominal aortic aneurysm presentation: a surgical dilemma
a Department of Surgery, Section of Cardiac Surgery, Cardiac Sciences Program, St. Boniface General Hospital, Winnipeg, Manitoba, Canada Received 14 February 2009; received in revised form 9 April 2009; accepted 14 April 2009
*Corresponding author. Department of Surgery, University of Manitoba, 409 Tache Avenue, Room Z-3028, St. Boniface General Hospital, Winnipeg, MB, R2H 2A6, Canada. Tel.: +1 (204) 237-2571; fax: +1 (204) 237-3429.
Concomitant valvular and abdominal aortic pathologies, both requiring urgent surgical interventions, are an uncommon entity. The ideal surgical management of such a scenario varies, depending on a host of variables. Due to its complexity and rarity, the ideal management approach remains an unknown. We describe a patient who presents with a delayed diagnosis of concomitant Salmonella species mitral valve (MV) endocarditis and mycotic abdominal aortic aneurysm (AAA). Though both clinical entities required urgent surgical intervention, the presence of one made intervening for the other high-risk and created a surgical dilemma. Following guarded conservative medical management, the patient underwent successful staged surgical interventions.
Key Words: Salmonella; Endocarditis; Mitral valve; Aortic aneurysm
Native valve endocarditis due to Salmonella, although previously reported, remains quite rare. With improvements in surgical intervention, the mortality rate associated with Salmonella endocarditis has fallen over the past two decades, from 69% to 20% [1]. In addition to cardiac valve involvement, Salmonella is now the most common cause of infectious aortitis; responsible for one-third of the cases [2]. Infectious aortitis on a whole remains an uncommon finding, representing  2.6% of all abdominal aortic aneurysms (AAA). Despite surgical intervention, mortality from infectious aortitis remains significantly high with rates varying between 21 and 44% [2]. We present a very unusual case of a patient who presented with a diagnosis of concomitant Salmonella valvular endocarditis and mycotic AAA. Despite seeking medical treatment on several occasions for ‘viral-like’ symptoms, intermittent watery diarrhea, and non-specific abdominal pain following an overseas trip, the definitive diagnosis was delayed.
A 62-year-old female, with a known history of rheumatic mitral valve (MV) disease with associated regurgitation (NYHA class I symptoms) and an AAA of unclear etiology, presented to hospital with signs and symptoms consistent with septic shock. Positive findings on exam included a pansystolic murmur and generalized abdominal pain. Broad-spectrum anti-microbial therapy was started with the suspicion of endocarditis. Bacterial endocarditis was subsequently confirmed with blood cultures positive for Salmonella enteritidis and a transthoracic echocardiogram (TTE) demonstrating a rheumatic MV with bileaflet vegetations measuring 10 mm. There was associated moderate MV regurgitation with preserved left ventricular size and function. In lieu of her medical and travel history, the 3.9 cm saccular AAA discovered during a work-up for a 2–3 months history of on-going abdominal pain, was now felt to be mycotic in nature (Fig. 1a). Shortly after admission, the patient had two separate embolic events to the left popliteal artery (Fig. 1b) and the spleen. In addition, despite focused antimicrobial therapy, serial TTE examination revealed that the anterior MV leaflet vegetation had grown in size (20 mmx30 mm). With approximately four weeks of intravenous antibiotics, stabilized heart failure status, and quiescent aortic pathology, a staged surgical procedure was decided as the most appropriate treatment strategy, with MV replacement as the initial step.
Intra-operative transesophageal echocardiogram confirmed the large vegetation attached to the anterior MV leaflet with severe MV regurgitation (Fig. 2a). Following a trans-septal approach to the MV, interrogation revealed that it was severely diseased with the endocarditic process (Fig. 2b). After extensive debridement, the MV was replaced with a mechanical prosthesis. After a two-week convalescence period with on-going intravenous antibiotics, the aneurysm surgery was undertaken. Following the exclusion of the AAA, an extra-anatomic (right axillo-bifemoral) bypass was successfully performed. After an extended period of recovery for on-going intravenous antibiotic therapy and physical rehabilitation, the patient was successfully discharged 13 weeks after the initial admission.
From our review of the literature, this is the third reported case of native valve endocarditis and mycotic AAA [3, 4]; the first case involving a Salmonella pathogen. In addition to its rarity and unlike the previous two documented reports, the active endocarditic and mycotic AAA processes created a noteworthy surgical management dilemma. Although self-limiting in most, 5% of individuals with Salmonella gastroenteritis will go on to develop bacteremia [1]. Though both categories of Salmonella (typhoidal and non-typhoidal) have been reported to cause endocarditis, very little information is available to mandate a change in surgical practice. Aggressive medical therapy should be offered to the elderly, immunocompromised, those with co-morbidities, and patients with endovascular atherosclerotic lesions [5]. It is unknown if the patient had an underlying atherosclerotic aneurysm which became secondarily infected. Macedo et al. reviewed the imaging findings of infected aortic aneurysms over a 25-year period at the Mayo clinic. The majority (93%) were saccular aneurysms with the presence of paraaortic soft-tissue mass, stranding, and/or fluid in 48% of cases. Calcification adjacent to or involving aneurysmal aortic tissue was seen in 93% of cases. The presence of periaortic gas was seen only in a minority (7%) of cases [6]. Our CT-scan findings were consistent with this review, demonstrating the saccular nature of the calcified tissue.
Considering the patient's history of gastroenteritis, her manner of presentation (i.e. weight loss and relative rapid decline in functional status), growth of the aneurysm ( The current standard of practice for a mycotic aneurysm is urgent surgical correction due to the risk of aneurysm rupture [2]. In this case, the patient's tenuous heart failure status posed a significant peri-operative risk for major vascular surgery. In addition, the risk of subsequent graft infection would have been significant without addressing the active endocarditis. Equally problematic was the decision on the correct timing of the valve surgery. Considering the patient's complex endocarditis picture, the requirement for sufficient antibiotic treatment needed to be balanced against the factors promoting earlier valve intervention (embolization, vegetation size, heart failure status) [7]. In addition, with two distinct areas as a nidus for infection for either prostheses, a staged procedure was not the ideal solution. Conversely, considering age, sex, and heart failure status, the patient's ability to tolerate successful concomitant sternotomy and laparotomy procedures was questioned.
Though endovascular aneurysm repair (EVAR) therapies are now routinely performed in patients who are not ideal surgical candidates, the use has been limited in patients with infectious aortitis. There have been several case reports and series documenting the use of EVAR in patients with mycotic aneurysms [8]. A recent review by Kan et al. demonstrated an average 30-day and two-year survival rates of Due to its rarity and the manner of presentation, the benefits and risks of a single combined procedure vs. a staged procedure vs. an EVAR/MVR hybrid procedure for both infectious processes are not well-known. This presentation differs from the first case documented in that their patient was a younger male with relatively stable cardiac status; more importantly his valvular involvement only became apparent after his aneurysm surgery [4]. The second report documents a healed right-sided endocarditis in a 50-year-old male, making concomitant procedures possible; unlike this case involving an active and growing left-sided lesion [3]. While this case demonstrated a successful outcome using a staged strategy, this may not have occurred if certain factors had changed (persistence of the bacteremia, worsening heart failure, evidence of new emboli, or aneurysmal growth). With the involvement of several consultants, closely monitored progress, and a cautious well-planned surgical approach, a positive outcome was achieved for such a complex case.
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Abstract
1. Introduction
