Predicting Infection Related Complications After Endovascular Repair of Infective Native Aortic Aneurysms.

OBJECTIVE: Endovascular aortic repair (EVAR) as surgical treatment for infective native aortic aneurysm (INAA) is associated with superior survival compared with open surgery, but with the risk of infection related complications (IRCs). This study aimed to assess the association between baseline clinical and computed tomography (CT) features and the risk of post-operative IRCs in patients treated with EVAR for INAA. It also sought to develop a model to predict long term IRCs in patients with abdominal INAA treated with EVAR. METHODS: All initial clinical details and CT examinations of INAAs between 2005 and 2020 at a major referral hospital were reviewed retrospectively. The images were scrutinised according to aneurysm features, as well as peri-aortic and surrounding organ involvement. Data on post-operative IRCs were found in the patient records. Cox regression analysis was used to derive predictors for IRCs and develop a model to predict five year IRCs after EVAR in abdominal INAA. RESULTS: Of 3 780 patients with the diagnosis of aortic aneurysm or aortitis, 98 (3%) patients were treated with EVAR for abdominal INAAs and were thus included. The mean follow up time was 52 months (range 0 ‒ 163). The mean transaxial diameter was 6.5 ± 2.4 cm (range 2.1 ‒14.7). In the enrolled patients, 38 (39%) presented with rupture. The five year IRC rate in abdominal INAAs was 26%. Female sex, renal insufficiency, positive blood culture, aneurysm diameter, and psoas muscle involvement were predictive of five year IRC in abdominal INAA after EVAR. The model had a C-index of 0.76 (95% CI 0.66 - 0.87). CONCLUSION: Pre-operative clinical and CT features have the potential to predict IRC after endovascular aortic repair in INAA patients. These findings stress the importance of rigorous clinical, laboratory, and radiological follow up in these patients.

Endovascular therapy for infected aortic aneurysms.

OBJECTIVE: To determine the outcome of endovascular therapy for an infected aortic aneurysm in patients with or without aorto-aerodigestive/aortocaval fistulas. METHODS: From September 2005 to May 2010, 21 patients, 17 abdominal and four thoracic infected aortic aneurysms were treated with an endovascular stent graft at Songklanagarind Hospital, Thailand. Five patients presented with fistula complications, 1 aortoesophageal, 1 aortobronchial, 1 aortocaval, and 2 aortoenteric fistulas. Lifelong antibiotics were planned for all patients. In-hospital mortality and follow-up outcomes were examined. RESULTS: The average age was 66 years (range, 42-84) and 18 patients were male. All five cases in the fistulous group presented with symptoms related to the organs involved, four massive bleedings and one congestive heart failure. Symptoms of patients in the nonfistulous group were abdominal, back, or chest pain in 94%, fever in 81%, and diarrhea in 19%. Blood culture was positive in 10 patients (48%): eight Salmonella spp and two Burkholderia pseudomallei. The overall in-hospital mortality was 19% (4/21): 60% (3/5) in the fistula group and only 6% (1/16) in the nonfistula group. One conversion to open repair was performed in the fistula group 2 weeks after the endovascular procedure. During the follow-up period, one of the two survivors in the fistula group died at 18 months from unrelated causes, while there were no deaths in the 15 patients of the nonfistula group with an average patient follow-up of 22 months (range, 1-54). Periaortic inflammation and aneurysms in the nonfistula group completely disappeared in 10 of the 15 patients (67%). The aneurysm significantly shrunk in four patients (27%), and was stable at 1 month in one patient. There were no late conversions. CONCLUSION: Endovascular therapy, as a definite treatment for infected aortic aneurysms, provided excellent short- and medium-term results in patients without fistula complications. However, a poorer outcome was evident in patients with fistula complications.