Aorta after stent grafting for mycotic aneurysm

Alpagut, Ufuk; Ugurlucan, Murat; Tireli, Emin; Rozanes, Izzet; Dayioglu, Enver

doi:10.1590/S0066-782X2011001300016

Abstracts

Endovascular stent grafting is applied for the treatment of different aortic pathologies in the current medical era. It may be lifesaving in patients with comorbidities and virtually inoperable when adopting conventional techniques. This manuscript reports on a 40-year-old patient, who was previously treated for a mycotic saccular aneurysm at the aortic arch and who presented with a descending aortic rupture at the mid-term follow-up. The descending aortic rupture was also managed successfully by endovascular measures.

Aorta, thoracic; blood vessel prosthesis; aortic aneurysm, thoracic; aneurism, infected

Endopróteses vasculares são atualmente utilizadas no tratamento de diferentes patologias da aorta. Podem salvar a vida de pacientes com comorbidades e virtualmente inoperáveis quando da utilização de técnicas convencionais. Esse manuscrito relata o caso de um paciente de 40 anos, que havia sido previamente tratado de um aneurisma micótico sacular no arco aórtico e que apresentou ruptura da aorta descendente no seguimento de médio prazo. O tratamento da ruptura da aorta descendente também foi realizado através de medidas endovasculares, com sucesso.

Aorta torácica; prótese vascular; aneurisma da aorta torácica; aneurisma infectado

Endoprótesis vasculares son actualmente utilizadas en el tratamiento de diferentes patologías de la aorta. Pueden salvar la vida de pacientes con comorbilidades y virtualmente inoperables con la utilización de técnicas convencionales. Este manuscrito relata el caso de un paciente de 40 años, que había sido previamente tratado de un aneurisma micótico sacular en el arco aórtico y que presentó ruptura de la aorta descendente en el seguimiento de medio plazo. El tratamiento de la ruptura de la aorta descendente también fue realizado a través de medidas endovasculares, con éxito.

Aorta torácica; prótesis vascular; aneurisma de la aorta torácica; aneurisma infectado

CASE REPORT

Istanbul University Istanbul Medical Faculty, Department of Cardiovascular Surgery, Istanbul, Turkey

Mailing Address

ABSTRACT

Endovascular stent grafting is applied for the treatment of different aortic pathologies in the current medical era. It may be lifesaving in patients with comorbidities and virtually inoperable when adopting conventional techniques. This manuscript reports on a 40-year-old patient, who was previously treated for a mycotic saccular aneurysm at the aortic arch and who presented with a descending aortic rupture at the mid-term follow-up. The descending aortic rupture was also managed successfully by endovascular measures.

Keywords: Aorta, thoracic/abnormalities; blood vessel prosthesis; aortic aneurysm, thoracic; aneurism, infected.

Introduction

Aneurysms at the arch and thoracic levels of the aorta are more frequently encountered in the current era. Despite advances in surgical techniques and in perioperative anesthesiological and postoperative reanimation care facilities, the surgical treatment of the aneurysms of the critical segments, i.e., the aortic arch and branching regions, still account for considerable mortality and morbidity rates¹.

The promising results of endovascular stent graft repair of abdominal aortic aneurysms has attracted physicians and so special interest was directed to the use of this technique for the treatment of aneurysms at different segments of the arterial tree. At present, the procedure is applied when treating different kinds of aneurysms at nearly all regions of the whole arteriovenous network².

Although, at first, the proposed technique was meant for surgically high-risk candidates, successful mid-term results of the surgical modality challenged the boundaries of indications of endovascular treatment. Despite the contradictory nature of the treatment of infected aneurysms, endoluminal stent grafting is also applied for the treatment of mycotic aneurysms^2-8. Currently, long-term results are not available; however, short and mid-term results of the treatment have been promising^2-8, when compared to conventional extensive debridement and artificial graft replacement or extra-anatomic bypass procedures^1,2.

In this report, we present the results of a 40-year-old patient in the mid-term follow up who was previously treated with endovascular stent grafting for mycotic saccular aneurysm at the aortic arch.

Case Report

The patient was a 40-year-old male with a history of acute lymphoblastic leukemia, ankylosing spondylitis and chronic hepatitis B infection. On his first admission, he had been diagnosed with Ortner's syndrome secondary to mycotic saccular aneurysm at the distal aortic arch (Figure 1), 1.5 years ago. It (What does "it" refer to?) preceded pneumonia following his first dose of chemotherapy for leukemia. He had undergone endoluminal stent graft treatment covering the distal aortic arch and the proximal portion of the descending aorta in order to exclude the aneurysm. Multiple blood cultures obtained before and after the treatment at that time did not reveal any positive results for possible microorganisms. However, the decision was made to initiate lifelong antibiotic therapy with co-trimoxazole². Since then, the patient has been symptom-free and has been regularly followed and treated by the cardiovascular surgery and hematology institutions. Because of his comorbidity status, mostly due to leukemia, the preliminary stent grafting used for the treatment of the mycotic saccular aneurysm at the aortic arch was not considered as a bridge to definitive treatment.

However, unexpectedly, the patient was admitted with acute onset back-flank pain and underwent thoracoabdominal computed tomography angiography. The diagnosis was rupture of the descending aorta, from the region immediately at the end of the stent graft (Figure 2A-B). The decision was to treat him with endovascular stent grafting. Intervention was performed under general anesthesia. The Stent graft system (Talent Thoracic Stent Graft, Medtronic AVE, Coil Track TDS) was deployed from the right femoral artery, anchored to the previous stent graft in the descending aorta and the region of rupture was excluded successfully (Figure 3A-B). Multiple blood cultures were obtained as soon as the diagnosis was made, before and after the stent graft repair. However, a possible causative agent could not be cultivated. Postoperative course was uneventful and the patient was discharged with lifelong antibiotic recommendation with co-trimoxazole.

The patient was followed and remained asymptomatic for a one-year period after the treatment, but unfortunately died due to the complications of acute lymphoblastic leukemia.

Discussion

The mycotic aortic aneurysms constitute approximately 1% of all aneurysms². The classical treatment of the disease includes open surgical procedures with extensive debridement of the tissues at the vicinity of the aneurysm and resection of the diseased aortic segment. Revascularization of the distal vascular bed can be mediated with in situ grafts or extra-anatomic bypass procedures. However, this procedure carries the risk of increased mortality and morbidity^1-3.

With the advances in endovascular stent graft treatment modalities and despite the controversies, endovascular treatment is also currently used for the treatment of mycotic aneurysms^2-7. Although, in the early term it may be life saving, long term results are still lacking in order to establish the method as a standard therapy for mycotic aneurysm repair.

The literature contains successful mid-term results of endovascular mycotic aneurysm repair in up to 33 months³. However, similar cases have also been presented with peripheral seeding⁶ or rupture of the pseudo aneurysm proximal to the stent graft⁷. Our patient had undergone endovascular stent graft treatment of mycotic saccular aneurysm at the aortic arch² and had been asymptomatic for 18 months until he presented with the rupture of descending aorta from the distal margin of the stent graft.

Another issue with the endovascular mycotic aneurysm repair is the postoperative treatment of the patients. Since the etiology still remains after the exclusion with endovascular stent graft, the antibiotic therapy is a matter of concern. It is difficult to detect a causative agent in a case as the blood cultures may be negative² and so deciding on the appropriate antibiotic type is complicated. Hence, there is no consensus in the literature on the type and duration of antibiotic therapy. Many authors recommend postoperative antibiotic use^2-7, and even sometimes lifelong therapy^2-6.

The endovascular stent grafting may also be preferred as a bridge to surgical repair. When used for the treatment of mycotic aneurysms, aorto-enteric, aorto-esophageal or aortobronchial fistula, there is a high probability that the most recent stent-graft implant may become infected and may lead to a greater problem. Therefore, some authors prefer endovascular stent grafting as the initial life saving procedure and to perform the definitive treatment when the patients are in stable conditions⁸. In our case, the patient had multiple comorbidity factors, the most important being the active leukemia. Further additional invasive interventions, such as surgical repairs, were not planned and so the strategy was to prescribe lifelong oral antibiotic therapy and follow the patient closely with regular outpatient clinic controls.

In conclusion, endovascular treatment may be lifesaving in patients with comorbidities and virtually inoperable when adopting conventional techniques. A careful follow-up is mandatory after endovascular mycotic aneurysm repair. The creation of a multicentric database consisting of data on the pathology with the proposed treatment modality will help to provide guidelines for the method.

Acknowledgement

The authors would like to thank Ms. Toni Spring for the linguistic revision of the manuscript.

Potential Conflict of Interest

No potential conflict of interest relevant to this article was reported.

Sources of Funding

There were no external funding sources for this study.

Study Association

This study is not associated with any post-graduation program.

References

1. Hsu RB, Lin FY. Surgery for infected aneurysm of the aortic arch. J Thorac Cardiovasc Surg. 2007;134 (5):1157-62.
2. Alpagut U, Ugurlucan M, Kafali E, Surmen B, Sayin OA, Guven K, et al. Endoluminal stenting of mycotic saccular aneurysm at the aortic arch. Tex Heart Inst J. 2006;33(3):371-5.
3. Kpodonu J, Williams JP, Ramaiah VG, Diethrich EB. Endovascular management of a descending thoracic mycotic aneurysm: mid-term follow-up. Eur J Cardiothorac Surg. 2007;32(1):178-9.
4. Razavi MK, Razavi MD. Stent-graft treatment of mycotic aneurysms: a review of the current literature. J Vasc Interv Radiol. 2008;19(6 Suppl):S51-6.
5. Tiesenhausen K, Hessinger M, Tomka M, Portugaller H, Swanidze S, Oberwalder P. Endovascular treatment of mycotic aortic pseudoaneurysms with stent-grafts. Cardiovasc Intervent Radiol. 2008;31(3):509-13.
6. Parkinson TJ, Rosales C, Wyatt MG. Peripheral seeding of mycotic aneurysms from an infected aortic stent graft. Eur J Vasc Endovasc Surg. 2007;33(6):684-6.
7. Aziz S, McWilliams R, Rashid A, Gosney JR, Harris PL, Stables RH. Late aortic rupture due to stent margin pseudoaneurysm formation complicating endovascular stent graft repair of a thoracic aortic mycotic aneurysm. Eur J Vasc Endovasc Surg Extra. 2006;12(3):30-4.
8. Sessa C, Costache V, Porcu P, Thony F, Blin D, Brichon PY, et al. Tracheoinnominate artery fistula: combined endovascular and surgical management by emergency stent-graft placement followed by cryopreserved arterial allograft repair. Ann Vasc Surg. 2006;20(6):731-5.