EComment. Mycotic aortic aneurysms: a real challenge for the cardiac surgeon

Abstract

We read with great interest the manuscript by Yano et al. regarding the surgical treartment of a mycotic aneurysm of ascending aorta [1]. We agree with the authors that the surgical repair of mycotic aortic aneurysms (extensive debridement of infected tissues, irrigation of the operative field with saline solution or antiseptic fluid and in situ reconstruction of the aorta) combined with wrapping of the prosthetic graft with pedicled omentum and administration of long-term antibiotics for prevention of the recurrence of infection is an acceptable mode of treatment [1]. Rifampicin-bonded prosthetic grafts can offer very good mid-term results. Uchida et al., in their retrospective study of 23 patients with mycotic aneurysms (6in thoracic aorta, 8 in thoracoabdominal aorta and 9 in abdominal aorta), who treated with in situ replacement of aorta with these grafts (plus omental pedicle grafts) found out that the overall survival at 5 years and freedom from aortic events was 95% and 86%, respectively. One patient died in the hospital due to recurrence of infection and another one required reoperation in another site of the aorta [2]. In addition, cryopreserved arterial homografts can be considered the treatment of choice and is our preferred option. Vogt et al., in their retrospective study of 19 patients with mycotic aneurysms (9/19) or infected grafts (10/19), in the thoracic (7/19) or abdominal aorta (12/19), apart from 16.2% mortality (1 early and 2 late deaths) didn't report on any recurrence of infection, homograft problems or anastomotic aneurysms in a mean follow-up period of 18.6 ± 13 months [3]. Silver-coated Dacron grafts compared to cryopreserved arterial homografts are reportable safe and present no significant difference in the treatment of infected abdominal aorta (in early mortality and mid-term survival) [4]. During the last years there is an increased use of thoracic endovascular stents and this modality of treatment has to be considered in the management of the complex cases, but with a higher incidence of recurrent infection. Patel et al., in their retrospective study of 20 patients with endovascular stenting of infected aortic pathological cases including 4 with infected grafts (10 aortobronchial fistulae, 2 aorto-oesophageal fistulae, 1 aortocutaneous fistula and 7 mycotic aneurysms) had an in-hospital mortality of 15%. Arch repair was needed in 8 patients, total descending, in 6 patients. Three patients underwent hybrid thoracic endovascular repair or debranching procedures. Mean Kaplan-Meier survival was 39.0 months. Late mortality was seen in 13 patients (history of immunosuppression and concurrent malignancy in 4 and 5 patients respectively) with 3 related to recurrent infection of thoracic aorta [tendency for recurrence when endovascular stent was performed in an infected graft (p = 0.08)]. At last imaging follow-up, 14 patients had a healed aorta [5]. In conclusion, conventional surgical treatment (with cryopreserved homografts or mycotic resistant prosthetic grafts or omental wrapping) is still the treatment of choice. However, knowing and understanding its limitations, the consideration of endovascular treatment in challenging, high-risk patients may offer acceptable results. Conflict of interest: none declared