Indian Journal of Vascular and Endovascular Surgery

CASE REPORT
Year
: 2019  |  Volume : 6  |  Issue : 3  |  Page : 184--186

Treatment of infected aortic aneurysms: Case reports and review of the literature


Pranay Pawar1, Jithin Jagan2, Radhakrishnan Raju2, MK Ayyappan2, Kapil Mathur2,  
1 Department of Vascular and Endovascular Surgery, Sri Ramachandra Medical College, Chennai, Tamil Nadu, India
2 Department of Vascular Surgery, Sri Ramachandra Medical University, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. Pranay Pawar
Department of Vascular and Endovascular Surgery, Sri Ramachandra Medical College, Chennai, Tamil Nadu
India

Abstract

Management of infected aortic aneurysms remains one of the most challenging clinical problems for the vascular surgeon, as they are rare and difficult to treat. Curative treatment is achieved by removal of all infected native tissue followed by a vascular reconstruction. Endovascular repair can also be used as a “bridge therapy” to reduce the mortality in these patients.



How to cite this article:
Pawar P, Jagan J, Raju R, Ayyappan M K, Mathur K. Treatment of infected aortic aneurysms: Case reports and review of the literature.Indian J Vasc Endovasc Surg 2019;6:184-186


How to cite this URL:
Pawar P, Jagan J, Raju R, Ayyappan M K, Mathur K. Treatment of infected aortic aneurysms: Case reports and review of the literature. Indian J Vasc Endovasc Surg [serial online] 2019 [cited 2019 Dec 11 ];6:184-186
Available from: http://www.indjvascsurg.org/text.asp?2019/6/3/184/265770


Full Text



 Introduction



Infected aortic aneurysms comprise a minority of all aortic aneurysms (0.65%–2%). They are potentially lethal and their management remains challenging due to their rapidly progressive clinical course and fatal outcomes. The recommended treatment policy is open repair with surgical resection of the infected aorta, extensive debridement of the infected tissue, and aortic reconstruction with either in situ graft or extra-anatomic bypass.[1] We describe two cases of infected aortic aneurysms that were managed at our center.

 Case Reports



Case 1

A 54-year-old man presented with low-grade fever and lower abdominal pain for 10 days before admission. He was under treatment at a nearby clinic and was referred due to worsening of the abdominal pain. On examination, his pulse rate was 120/min, blood pressure was 140/60 mmHg, and his temperature was 100°F. His systemic examination was unremarkable and his distal pulses were palpable. His preliminary investigations revealed a total leukocyte count (TLC) of 23,700 and a C-reactive protein (CRP) of 5.6 with a normal two-dimensional (2-D) echo. His computed tomography angiogram (CTA) revealed well-defined peripherally enhancing collection of size 7.5 cm × 8.8 cm × 6 cm at the distal abdominal aorta just proximal to the bifurcation with two saccular aneurysms (3.3 cm × 2.0 cm × 3.2 cm and 2.8 cm × 1.4 cm × 3.4 cm) at the level of this collection. A prostatic collection of 6–10 cc was also noted. A diagnosis of an infected aortic aneurysm was made, and the patient was empirically started on cefoperazone-sulbactam and vancomycin and was taken up for a laparotomy the following day. A midline laparotomy was performed, and after taking proximal and distal controls, the aneurysm was opened. There was a large cystic mass with purulent fluid and large lymph nodes surrounding the aorta. The mass and the aorta were excised, and a thorough debridement and lavage of the area was performed. Simultaneously, the right femoral popliteal vein was harvested and was fashioned into a pantaloon aortobiiliac graft. The proximal anastomosis was performed with 4–0 prolene and the distal iliac with 5–0 prolene. The graft was covered with omentum and the abdomen was closed in layers. The tissue and blood culture both grew Burkholderia cepacia, for which appropriate sensitive antibiotics were started. This case was published in the same journal at an earlier date[2] [Figure 1] and [Figure 2].{Figure 1}{Figure 2}

Case 2

A 51-year-old man presented with low-grade fever and abdominal pain for 3 weeks. He was diagnosed with typhoid fever and had completed the treatment course at another hospital. On presentation, his pulse rate was 120/min, blood pressure was 110/70 mmHg, and temperature was 102°F. His baseline investigations showed a TLC of 17,300 with a CRP of 5.2 and a normal 2-D echo. His systemic examination was unremarkable and his distal pulses were normal. His CTA revealed an irregular nodal mass measuring 3.6 cm × 3.0 cm × 2.5 cm in the distal abdominal aorta just proximal to the bifurcation with a 1.0 cm × 0.8 cm saccular outpunching present in the mass. A working diagnosis was made of an infected aortic aneurysm, and the patient was started on ceftriaxone and vancomycin in view of his history of enteric fever. After a week of antibiotic therapy, the patient was taken up for a midline laparotomy. The operative findings were of a 4 cm × 5 cm nodal mass with a saccular aneurysm of the infrarenal aorta. The affected part was excised, and a thorough debridement was done after proximal and distal controls. An aortobiiliac bypass was performed with a rifampicin-soaked dacron graft. The tissue culture grew Citrobacter species and sensitive antibiotics were continued for 6 weeks [Figure 3] and [Figure 4].{Figure 3}{Figure 4}

 Discussion



Sir William Osler first reported infected aortic aneurysms in 1885 and used the misnomer term mycotic to describe the appearance of fresh fungal vegetation on the intimal surface of an aortic aneurysm in a patient with bacterial endocarditis.[3] Infected aortic aneurysms comprise a minority of all aneurysms but continue to be challenging to treat due to delayed presentations with rupture, complex aneurysms in immunocompromised hosts and controversy over the ideal treatment.

There are four types of infected aortic aneurysms based on etiology:

Microbial arteritis with aneurysm formation due to noncardiac origin bacteremia or contiguous spread of a localized infectionPosttraumatic infected pseudoaneurymsInfection of preexisting aneurysms from bacteremiaInfected aneurysms from septic emboli.[4]

Since the introduction of antibiotics, the predominant organisms Streptococcus pyogenes, pneumococcus, and Enterococcus species have become less common, and Staphylococcus aureus and Salmonella species have become the dominant infecting organisms. Salmonella species exhibit a more virulent course due to their ability to invade the normal intima and cause early aneurysm rupture.[5]

The gold standard of treatment is resection, debridement of infected tissues, and graft replacement either by in situ or by extra-anatomic bypass. Many adjunctive procedures such as (a) omental or pedicled muscle flap to isolate the graft, (b) biologic materials such as a homograft or a vein graft, and (c) a silver-coated or antibiotic-soaked dacron graft have been proposed to avoid recurrent infection.[6]

The neo-aortoiliac system bypass was described by Clagett. During this procedure, the infected material is removed and is replaced by a graft constructed from the femoral and popliteal veins. The advantages of this procedure are that there is no synthetic material introduced, which minimizes the risk of recurrent infection, there is no risk of blowout associated with a blind suture closure of the aorta in an infected surgical field, and secondary occlusion of the reconstruction is rare due to a high arterial volume flow and low thrombogenicity.[7]

Over the last decade, endovascular aneurysm repair (EVAR) of thoracic and abdominal aortic aneurysms has become widely accepted. However, reports on mycotic aortic aneurysms have been controversial. Semba et al. were the first to describe EVAR of three mycotic aneurysms. Compared with open repair, the unresected infected aneurysm sac and the surrounding tissue may cause persistent sepsis and late prosthetic graft infection, are the major concerns after EVAR. On the other hand, usage of a stent graft does not preclude later open repair, and in a situation of impending rupture, it could be used as a “bridge to surgery” and EVAR rapidly stops aneurysm expansion and has relatively less hemodynamic instability, which is a primary risk factor for mortality in open repair.[1],[8],[9]

Targeted antibiotic treatment leads to significant decrease in the mortality rate, and maximum effort should be made to identify the infectious agent. It is appropriate to continue the antibiotic treatment for 4–8 weeks after surgery, and in cases of Salmonella, a treatment period of at least 6 months is advised.[10]

 Conclusion



Infected aortic aneurysms have an aggressive presentation and a complicated early outcome. Early diagnosis and aggressive treatment personally tailored to the patient will ensure favorable outcomes in this disease.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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