Indian Journal of Vascular and Endovascular Surgery

CASE REPORT
Year
: 2019  |  Volume : 6  |  Issue : 2  |  Page : 135--137

Complete aortic thrombosis in a ruptured mycotic aneurysm due to infection with Burkholderia pseudomallei


Darpa Narayan Hazra, Indrani Sen, Amit Mahajan, Sunil Agarwal 
 Department of Vascular Surgery, Christian Medical College and Hospital, Vellore, Tamil Nadu, India

Correspondence Address:
Dr. Darpa Narayan Hazra
Department of Vascular Surgery, Christian Medical College and Hospital, Vellore, Tamil Nadu
India

Abstract

Complete thrombosis of the aorta in patients with abdominal aneurysms is extremely rare. The risk factors, natural history, and rupture risk are not well known. We report a case of a complete aortic thrombosis in a ruptured infrarenal mycotic aneurysm caused due to infection with Burkholderia pseudomallei.



How to cite this article:
Hazra DN, Sen I, Mahajan A, Agarwal S. Complete aortic thrombosis in a ruptured mycotic aneurysm due to infection with Burkholderia pseudomallei.Indian J Vasc Endovasc Surg 2019;6:135-137


How to cite this URL:
Hazra DN, Sen I, Mahajan A, Agarwal S. Complete aortic thrombosis in a ruptured mycotic aneurysm due to infection with Burkholderia pseudomallei. Indian J Vasc Endovasc Surg [serial online] 2019 [cited 2020 Apr 6 ];6:135-137
Available from: http://www.indjvascsurg.org/text.asp?2019/6/2/135/259659


Full Text



 Introduction



We report a case of complete aortic thrombosis in a ruptured mycotic aneurysm due to infection with Burkholderia pseudomallei. Mycotic aneurysms usually present with fever and other nonspecific symptoms. Complete aortic thrombosis is reported with atherosclerotic aneurysms; however, association with a ruptured mycotic aneurysm is rare. The presence of a high thrombus load correlates to an increased rupture risk. Open repair with long-term antibiotics is a feasible treatment option in such a patient. We report a case of a complete aortic thrombosis in a ruptured infrarenal mycotic aneurysm caused due to infection with B. pseudomallei.

 Case Report



A 65 years old gentleman presented to the emergency department with complaints of severe back pain and fever for 15 days. On examination, his pulse rate was 95 bpm and blood pressure was 140/80 mmHg. Examination of the abdomen revealed a large tender pulsatile swelling in the epigastric and left hypochondrial region with absent pulses in both femoral and lower limbs. General examination was unremarkable. He did not have a history of fever or any other complaints on systematic review. He was a farmer and had regular exposure to soil – he tilled land barefoot.

Initial blood investigations showed raised total counts of 12,600/cumm (83% neutrophils). Urine microscopy revealed leukocytosis. Computed tomography angiogram (CTA) identified a 6.7 cm × 5.2 cm saccular juxtarenal aortic aneurysm with periaortic inflammation, aortitis, and contained rupture [Figure 1]. The vertebrae were normal. CT also revealed multiple peripheral splenic and renal infarcts. The mesenteric vessels were normal; superiorly, the periaortic inflammation extended till the level of the superior mesenteric artery. There was complete aortic cutoff with coexistent rupture [Figure 2]. There were no other intra-abdominal collections. Ultrasound screening of the renal and splenic lesions confirmed that the lesions seen on CT were stable and there was no abscess formation.{Figure 1}{Figure 2}

The patient was started on meropenem and vancomycin after blood and urine culture with a suspicion of a mycotic aneurysm, following which he underwent open repair of the ruptured mycotic aneurysm. Intraoperatively, the superior and inferior mesenteric vessels were dissected free, and an infrarenal control was obtained. A primary supracoeliac control was considered; however, intraoperatively, this was avoided. The diseased aortic tissue was resected, and the thrombus was evacuated. The aorta was reconstructed with a Dacron graft. Blood, urine, aortic wall, and thrombus culture grew B. pseudomallei, which was susceptible to meropenem, doxycycline, and cotrimoxazole. The patient received 2 weeks of injectable followed by 6 months of oral antibiotics and was well at 6-month follow-up.

 Discussion



Spontaneous thrombosis of abdominal aortic aneurysms (AAAs) has a very low incidence of 0.7%–2.8%.[1] Chronic thrombosed AAAs are related to occlusive iliac disease. This is associated with several factors: surgical manipulation, trauma, fever, thromboembolic disease, dehydration, hypercoagulation, hypotension, atrial fibrillation, neoplasm, intraplaque hemorrhage, dislodgment of mural thrombus, iliac artery occlusive disease, and AAA rupture.[2] Such thrombosis does not eliminate the risk of expansion and rupture; mortality can be as high as 59%.[3] Patients with chronic thrombosis present with symptoms secondary to the obstructive iliac disease (limb claudication) and have better outcomes. Schumacker first reported thrombosed AAA in 1959. Most of the literature that references rupture of chronic thrombosis of AAA is linked to nonresective treatment of aortic aneurysms.[3] Mycotic aneurysms usually present with saccular, atypical morphology, multiple aneurysms, and periaortic inflammation. They expand rapidly and thus a high rupture risk. The most common causative organisms are Staphylococcus aureus and nontyphoidal Salmonella species.[4] Melioidosis (B. pseudomallei) is reported commonly from Southeast Asia and India. This organism enters the bloodstream through breaks in skin surface in patients with occupational exposure to soil. It has a high rate of morbidity, mortality, and relapse.[4] As in our case, the patient had presented with acute symptoms, radiological imaging ruled out any intra-abdominal collection, culture (blood, aortic wall, and thrombus) grew B. pseudomallei, and chances of a primary mycotic aneurysm are more likely. Our patient had a complete aortic cutoff and coexistent rupture, which is not been reported in mycotic aneurysms earlier. The aortic occlusion was due to the infected thrombus and the rupture due to the thinning of the aortic wall. The thrombus alters the normal pattern of oxygen supply to the aortic wall, leading to local hypoxia, wall weakening, and increased potential for rupture.[5] Compared with the thrombus-free wall, the aneurysm wall covered by the thrombus is thinner and contains fewer and fragmented elastin fibers as well as fewer, and more apoptotic or necrotic, smooth muscle cells, but more inflammatory cells. This implies that the thrombus may affect the structural integrity and stability of the wall by influencing the degradation of the extracellular matrix of the underlying vessel wall and thereby predisposing it for rupture.[6] A thicker layer of thrombus implies increased rupture risk [7] and aneurysm expansion. However, contrasting views exist; some authors support the view that the thrombus may prevent the aneurysm from rupture by reducing the aneurysmal wall stress.[8] Complete thrombosis may be precipitated by occlusive iliac artery disease, embolization, or displacement of the mural thrombus due to a change in aortic flow patterns. Thrombosis of an aneurysm (especially mycotic) is important with regard to management. Although endovascular repair of mycotic-ruptured aneurysms is possible, open repair still remains the treatment of choice. The latter may be a more durable option when the patient is otherwise fit and has a reasonably good life expectancy.

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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