Endovascular aortic graft infection resulting in retroperitoneal abscess: report of a case Enrico Ferri, Laura Magrini, Marco Alfano, Michela Del Parco, Chiara Serena Gori, Salvatore Di Somma Department of Emergency Medicine, AO Sant’Andrea, La Sapienza University of Rome, Rome, Italy Introduction Endovascular prosthetic grafts may be related to several complication including endoleak, device migration, restenosis, thrombosis, rupture and in- fection1-3. Infection is, to date, a rare complication of endovascular procedures, with an incidence in- ferior to 0.5% but potentially catastrophic4. When an endograft in the aortoiliac position is in- volved it may result, as in open surgery implanted, in a retroperitoneal abscess and aortoenteric fistu- lation potentially evolving to sepsis, gastrointesti- nal bleeding, septic or hemorragic shock2-7. The low rate of occurrence and awareness with the relatively aspecific clinical presentation and pro- gressive evolution seem to cause a considerably delay in diagnosis and a poor outcome2,3. Case report A 83 years old man with diabetes mellitus, hy- pertension and benign prostatic hypertrophy pre- sented to the Emergency Department (ED) refer- ring a one month history of low grade fever, back discomfort and dysuria associated with a subcu- taneous mass in the inferior right dorsum arising from few days. The patient underwent endovascu- lar treatment for an abdominal aortic aneurysm 12 months before and was on treatment with insulin, ramipril, aspirin and thamsulosin. He did not show any peri- or post-surgical com- plication. General physician visited the patient eight days be- fore the mass appearance and suspected an urinary tract infection. The patient underwent empiric antibiotic therapy with quinolones (ciprofloxacin 500 mg bid) for 5 days without any benefit. After performed an urine colture and waiting for the results, the antibiotic switched to a beta lattamase inibhitor penicillin (amoxicillin/clavulanate 1 g bid). At time of ED admission clinical examination de- tected hypotension (blood pressure 95/60 mmHg), tachycardia (heart rate 120), dehydration, a low grade dolorability in the right abdomen with- L’infezione è una rara complicazione delle procedure en- dovascolari a livello aorto iliaco con una incidenza in- feriore allo 0.5% e può determinare la comparsa di un ascesso retroperitoneale evolvente verso la sepsi e il san- guinamento gastrointestinale. In più del 50% dei casi le infezioni delle protesi endovascolari in sede aorto iliaca si manifestano a distanza di mesi o anni dalla procedura. In considerazione della recente applicazione e della pro- gressiva diffusione delle procedure endovascolari, è pre- vedibile un crescente aumento delle complicanze settiche post-procedurali che potrebbero rappresentare un proble- ma emergente per il medico d’urgenza. Il mantenimento di un alto indice di sospetto in presenza di un paziente portatore di protesi endovascolare aorto iliaca, con febbre prolungata o ricorrente e/o dolore addo- minale e/o dolore lombare, la richiesta precoce di una TC addome potrebbe migliorare la “performance” diagnosti- co terapeutica nel Dipartimento di Emergenza. SINTESI emergency care journal clinica e terapia em er ge nc y ca re jo ur na l - o rg an iz za zi on e, c lin ic a, ric er ca • A nn o V I n um er o 2 • G iu gn o 20 10 • w w w .e cj .it Materiale protetto da copyright. Non fotocopiare o distribuire elettronicamente senza l’autorizzazione scritta dell’editore. 7 out peritonism signs and an ovalar subcutaneous soft mass in the inferior right dorsum. Fever was 38.5°C. Laboratory revealed anemia (haemoglobin 6.5 g/dl), leucocytosis (white blood cells 18.600/ ul), increased c reactive protein (25.2 mg/dl), cre- atinine (2.6 mg/dl) and blood urea (56 mg/dl). Urine dipstick was positive for haematuria and leucocyturia. An urgent ultrasonography demon- strated a subcutaneous fluid mass communicating with the pleural space. This prompted an unhenanced thoraco abdominal CT which identified a periaortic retroperitoneal abscess with pleural and subcutaneos fistulation (Figure 1). A vascular surgical consultation has been per- formed but the patient deceased for septic shock two hours after the ED admission, and before any surgical procedure. Discussion Infectious complications are rare after endovascu- lar procedures and include septic embolization, periarterial and retroperitoneal abscess, sepsis and aortoenteric or inguinal fistulation2-7. These may occur early in the post surgical period but in more than 50% of cases months or years after the procedure3, recently Heyer et al. showed that the mean time from the index procedure to the diagnosis of infection was 243.6 days +/- 74.56. Once placed, the metallic stent is gradually and completely covered by endothelium in 4 weeks but the stented area may be more prone than native artery in capturing circulating bacteria3. Infection may arise from bacteria introduced at the time of angioplasty or stent placement by a failed steril technique or by germs present in the plaque3. Neverthless, in completely endothelium covered stent, any intervention next to the stented area could damage the endothelium determining an in- fection3,5. Coexisting neoplastic and immune disorders, in- flammatory bowel disease, concomitant adjunctive procedures and treatment of false aneurysm appar- ently seem to determinate an higher risk of bacte- rial arterial wall colonization3,5. Other risk factors for infection are the prolonged use of an indwelling catheter as in thrombolytic therapy, an hematoma formation and the re-use of the same artery for vascular access in a week2,3. It remains an uncommon occurrence and most cases have been described in single case reports1-7. In the aortoiliac site the frequency of endovascular stent graft infection is < 0.5%2,4. However, as the growing number of endovascular procedures, and as the actually midterm follow up in most cases, septic sequelae will no doubt con- tinue to occur with increased frequency and may represent an emerging problem in the ED for the emergency physician, because of his low familiar- ity with this patologic condition, of an increasing follow up lenghtiness, and because of potentially catastrophic complications and high mortality of this condition2-5. Endovascular graft infection begins with aspecific clinical manifestations, including fever, weak- ness, malaise, weight loss, abdominal, back, and leg pain, claudication, anemia, intestinal bleeding and elevated biochemical and inflammatory mark- ers1-3,6. But the evolution may be progressive to sepsis and to multiorgan failure syndrome or he- morragic shock2-5. CT scan is the imaging technique that produces the most reliable and rapid diagnosis1-3. A periprosthetic infection should be searched and excluded in any patient with an aortic stent graft Fig. 1 - An unhenanced thoraco abdominal CT identified a periaor- tic retroperitoneal abscess with pleural and subcutaneos fistulation (arrows). clinica e terapia em er ge nc y ca re jo ur na l - o rg an iz za zi on e, c lin ic a, ric er ca • A nn o V I n um er o 2 • G iu gn o 20 10 • w w w .e cj .it Materiale protetto da copyright. Non fotocopiare o distribuire elettronicamente senza l’autorizzazione scritta dell’editore. 8 Infection is a rare complication of aortoiliac endovascu- lar procedures, with an incidence inferior to 0.5%, and it may result in a retroperitoneal abscess potentially evolv- ing to sepsis and gastrointestinal bleeding. In more than 50% of cases endovascular aortoiliac pros- thetic grafts infection occur months or years after the procedure. The growing number of endovascular procedures, and as the actually midterm follow up in most cases, septic sequelae will no doubt continue to occur with increased frequency and may represent an emerging problem in the ED for the emergency physician. Endovascular graft infection begins with unspecific clini- cal manifestations. An high index of suspicion in any pa- tient with an aortic stent graft presenting prolonged or recurrent fever and or abdominal or back pain and a low threshold for obtaining CT scan should increase the clini- cian’s ability to make a timely diagnosis in the ED setting. ABSTRACT presenting prolonged or recurrent fever and or ab- dominal, back or flank pain. An high index of suspicion and a low threshold for obtaining CT scan should increase the clini- cian’s ability to make a timely diagnosis in the ED setting. References 1. Buth J, Laheij RJF. On behalf of the EUROSTAR Collaborators. Early complications and endoleaks after endovascular abdomi- nal aortic aneurysm repair; report of a multicentric study. J Vasc Surg 2000; 31(1 Pt 1): 134-146. 2. Ducasse E, Calisti A, Speziale F et al. Aortoiliac stent graft infec- tion: current problems and management. Ann Vasc Surg 2004; 18: 521-526. 3. Fiorani P, Speziale F, Calisti A et al. Endovascular graft infection: preliminary results of an international enquiry. J Endovasc Ther 2003; 10: 919-927. 4. Starr J, Walker G, Vaccaro P. Endograft infection presenting as a ruptured aortic aneurysm. Ann Vasc Surg 2009; 23 (6): 787.e7-9. 5. Sharif MA, Lee B, Lau LL et al. Prosthetic stent graft infection af- ter endovascular abdominal aortic aneurysm repair. J Vasc Surg 2007; 46: 442-448. 6. Heyer KS, Modi P, Morasch MD et al. Secondary infections of thoracic and abdominal aortic endografts. J Vasc Interv Radiol 2009; 20(2): 173-179. Epub 2008 Dec 20. 7. Chenu C, Marcheix B, Barcelo C, Rousseau H.. Aorto-enteric fistula after endovascular abdominal aortic aneurysm repair: case report and review. Eur J Vasc Endovasc Surg 2009; 37(4): 401-406. Epub 2009 Feb 10. clinica e terapia em er ge nc y ca re jo ur na l - o rg an iz za zi on e, c lin ic a, ric er ca • A nn o V I n um er o 2 • G iu gn o 20 10 • w w w .e cj .it Materiale protetto da copyright. Non fotocopiare o distribuire elettronicamente senza l’autorizzazione scritta dell’editore. 9