P882 Heart murmur in a 74-year-old patient with a Dacron aortic graft admitted for sepsis after a laparoscopic left colectomy

Introduction

Aortic graft infections (AGI) can have catastrophic consequences with an operative mortality of nearly 50%. The majority of AGI are a result of bacterial exposure at the time of operation (surgical-site related), nearly three quarters a caused by the Staphylococcus organisms. Late onset infections are less common. The mechanism can be through hematogenous spread and bacterial invasion of the graft. Diagnosis is challenging, done by a combination of clinical, radiological and laboratory findings in which echocardiography plays an important role. Fundamental tenets of AGI management are removal of the infected device and adjunctive antimicrobial therapy.

Case

A 74-year-old man, who had undergone supracoronary ascending aortic replacement in 2015 for an aneurism, visited our hospital with fever of 39°, general malaise and abdominal pain for the last 3 days. He had been discharged one week ago after laparoscopic left colectomy due to descending colon neoplasia. Physical examination showed a systolic heart murmur loudest over the left-upper sternal border. Hematological findings included C-reactive protein (CRP) of 82 mg/l and white blood cell count of 16 700/μl. Blood culture was positive por Pseudomonas aeruginosa. Transthoracic echocardiography revealed a supravalvular pulmonary stenosis (figure 1, A) Transesophageal examination showed an extensive peritubular collection (figure 1, B) that extended into the main pulmonary artery, conditioning extrinsic compression and severe stenosis. No blood flow was observed inside the collection. A 6 mm long and filiform image was detected on the right coronary leaflet, causing a moderate aortic regurgitation. Chest CT revealed a low density area around the vascular graft (figure 1, C) and the positron emission tomography (PET)-CT (figure 1, D) showed increased glucidic metabolism in the aneurysmal sac, periaortic fat and the proximal and distal portion of the prosthesis. With the diagnosis of prosthetic vascular graft infection, the patient was referred to cardiac surgery. The surgical sample cultures (graft and mediastinal pus) were all positive for P. aeruginosa. The patient completed antibiotic therapy with ceftazidime and gentamicine.

Discussion

AGI is an extremely complex clinical challenge. Mortality is high, and diagnostic and treatment approaches are controversial. Cardiovascular imaging is one of the most important diagnostic tools in the diagnosis. An echocardiogram should be done in every patient to look for findings of endocarditis. CT is the most informative radiologic study and can be also very helpful in identifying characteristics and extension of AGI. A concurrent PET-CT study has significant potential in improving diagnosis of AGI and monitoring response to treatment.Nevertheless there is an unavoidable degree of subjective judgment in the interpretation of imaging findings making clinical suspicion and laboratory findings crucial in determining whether an AGI exists.

Abstract P882 Figure.