Successful Endovascular Repair of a Thoracic Infected Aortic Aneurysm with Concomitant Liver Abscess: A Case Report

Introduction

An infected descending aortic aneurysm (IAA) is an uncommon but potentially fatal vascular condition resulting from microbial invasion of the aortic wall, which leads to aneurysmal degeneration, rapid enlargement, and possible rupture [1]. Although it can occur as an isolated infection, the concomitant presence of intra-abdominal infections such as liver abscesses is rare and clinically important due to shared hematogenous dissemination pathways and the increased risk of systemic bacteremia [2]. To date, reports of such simultaneous infections are very limited, making each case of high clinical value. Their co-occurrence often suggests a more aggressive disease course and demands early recognition in clinical practice.

The most commonly identified pathogens are Staphylococcus aureus and Salmonella species, both of which have a known affinity for vascular tissue and intra-abdominal organs. However, organisms such as Klebsiella pneumoniae have also been implicated in both infected aortic aneurysms and liver abscesses, particularly in immunocompromised hosts [3]. Affected individuals often present with nonspecific clinical features such as fever, malaise, abdominal or back pain, and laboratory findings indicative of systemic inflammation. Given this nonspecific presentation, diagnosis is frequently delayed, further complicating patient management. Contrast-enhanced computed tomography (CT) remains the primary imaging modality for identifying both IAA and hepatic abscesses. Effective management requires a multidisciplinary approach, typically involving prolonged intravenous antimicrobial therapy along with timely surgical or endovascular intervention [4]. This case report highlights the diagnostic complexity and therapeutic decision-making involved in managing such a rare and challenging co-infection, emphasizing the importance of integrating clinical suspicion with appropriate imaging to ensure timely diagnosis and optimal treatment outcomes.

Case Report

A 65-year-old woman presented to the Emergency Department with a 1-week history of epigastric pain and constipation. She also reported intermittent low-grade fever, generalized fatigue, and mild anorexia, without nausea, vomiting, chest pain, or weight loss. Her medical history was notable for hypertension and diabetes mellitus. On arrival, her vital signs included a blood pressure of 140/87 mmHg, a pulse rate of 121 beats per minute, and a body temperature of 38.3°C. Physical examination revealed normal breath sounds bilaterally, active bowel sounds, and mild tenderness in the epigastric region, without hepatosplenomegaly, peripheral edema, or focal neurological deficits. Laboratory tests showed leukocytosis, with a white blood cell count of 13.7×103/μL (reference range: 4.2–10.3×103/μL), and a markedly elevated C-reactive protein level of 42.0 mg/dL (normal: <1.0 mg/dL). A chest radiograph demonstrated an abnormal opacity in the left lower lung field (Figure 1). Differential diagnoses at this stage included pneumonia, acute cholecystitis, cholangitis, subphrenic abscess, and other intra-abdominal or retroperitoneal infections.Given the concern for thoracic or intra-abdominal infection, contrast-enhanced computed tomography (CT) of the chest and abdomen was performed (Figure 2). Imaging revealed a focal aneurysmal dilatation of the descending thoracic aorta measuring approximately 8.0×7.1×5.0 cm, with an irregular wall and surrounding fat stranding, consistent with a mycotic aneurysm (Figure 2A). A hypodense lesion in the right hepatic lobe with peripheral enhancement was also noted, suggestive of a liver abscess (Figure 2B). The simultaneous identification of these 2 lesions, along with the absence of other intra-abdominal or pulmonary sources of infection, led to the diagnosis of IAA with concomitant liver abscess.

Empirical broad-spectrum antibiotic therapy with piperacillin-tazobactam and vancomycin was initiated. Given the patient’s and her family’s willingness, comorbidities (hypertension and diabetes), and the high perioperative risk associated with open surgical repair, thoracic endovascular aortic repair (TEVAR) was chosen as the primary intervention. This approach was expected to minimize surgical stress, reduce perioperative morbidity, and allow early infection control when combined with prolonged targeted antimicrobial therapy.

The patient subsequently underwent thoracic endovascular aortic repair (TEVAR) for the pseudoaneurysm (Figure 3A) and was admitted to the intensive care unit postoperatively. Blood cultures later yielded Klebsiella pneumoniae, which was sensitive to piperacillin-tazobactam; vancomycin was subsequently discontinued.

The patient’s clinical condition improved steadily with continued antibiotic therapy. She was discharged in stable condition after a 40-day hospitalization. This case highlights the rarity of the coexistence of thoracic IAA and liver abscess, which is seldom reported in the literature, and underscores the importance of early imaging and tailored therapeutic strategies in such high-risk patients. Follow-up CT performed 2 months after surgery during outpatient visits showed no evidence of recurrence (Figure 3B).

Discussion

The coexistence of an infected descending aortic aneurysm and a liver abscess is extremely rare and presents a significant clinical challenge, given the high morbidity and mortality associated with each condition. This combination often indicates either an unusually virulent pathogen or impaired host immunity that facilitates systemic dissemination. The underlying pathophysiology often involves hematogenous dissemination following transient or sustained bacteremia, resulting in microbial seeding of the arterial wall or hepatic parenchyma [5].

Our patient’s presentation with both thoracic IAA and a liver abscess caused by Klebsiella pneumoniae is consistent with reports from East Asia, where this pathogen is more prevalent; however, the simultaneous occurrence involving the thoracic aorta remains rare. The choice of TEVAR was guided by the patient’s high surgical risk and the anticipated benefits of a less invasive approach, such as reduced perioperative morbidity and faster recovery. Diagnostic difficulties included the nonspecific nature of symptoms, initial imaging findings that could be attributed to other conditions, and the need for rapid differentiation from other potential infection sources. To optimize case management, we focused on imaging and microbiological findings that directly influenced treatment decisions, avoiding extraneous technical details.

Infected aortic aneurysms, especially those in the thoracic or descending aorta, occur less frequently than abdominal aneurysms but have a higher risk of rupture due to delayed diagnosis. Their symptoms – fever, back pain, and malaise – are often nonspecific and may be misattributed to other systemic infections. Similarly, liver abscesses typically present with vague abdominal discomfort, fever, and elevated inflammatory markers, and are frequently cryptogenic, particularly in regions with high Klebsiella pneumoniae prevalence [6].

Diagnosis hinges on high clinical suspicion and comprehensive imaging. Contrast-enhanced CT remains the cornerstone of evaluation for both infected aortic aneurysms and liver abscesses, revealing saccular aneurysmal changes and hypodense hepatic lesions with rim enhancement. In selected cases, PET-CT may offer superior sensitivity in detecting metabolically active infection within the aortic wall, particularly when CT findings are equivocal [7].

Microbiological confirmation from blood cultures, abscess aspirates, or aortic tissue are essential for pathogen identification and guiding antimicrobial therapy. Uncommon pathogens, such as Clostridium septicum or fungal organisms, have been reported in immunocompromised hosts [8]. Isolation of the same organism from both the aortic tissue and liver abscess strongly supports hematogenous dissemination, and emerging diagnostic tools such as gas chromatography-ion mobility spectrometry for detecting acetoin as a biomarker of carbapenemase-producing Klebsiella pneumoniae may further enhance early identification and targeted management in similar cases [9].

Management generally requires a dual approach of extended intravenous antimicrobial therapy and timely source control, tailored to the patient’s clinical stability and anatomical considerations. While open surgical resection with graft placement remains the standard treatment for infected aortic aneurysms, it carries substantial perioperative risk [10]. TEVAR has emerged as a viable alternative for selected patients with prohibitive surgical risk, although concerns about persistent peri-graft infection remain [11]. Adjunctive procedures, such as muscle flap coverage of the infected site, have also been used to reinforce repairs and reduce reinfection risk [12]. The emergence of multidrug-resistant Klebsiella pneumoniae further complicates therapeutic decisions, underscoring the importance of selecting appropriate antibiotic regimens, as highlighted in recent case reports of critically ill patients [13].

Despite advances in diagnostics and treatment, prognosis remains guarded, with reported mortality rates ranging from 20% to 40% depending on the extent of infection, comorbidities, and timing of intervention [14]. Therefore, early diagnosis, aggressive pathogen-directed antimicrobial therapy, and a coordinated multidisciplinary approach are essential for improving outcomes in this rare but life-threatening condition.

Conclusions

This case demonstrates that timely diagnosis and a multidisciplinary strategy, including TEVAR and intravenous antibiotics, can effectively manage infected descending aortic aneurysm complicated by liver abscess in selected patients. Key lessons from this case include maintaining a high index of suspicion for rare co-infections in patients with nonspecific symptoms and considering TEVAR as a viable treatment option in high-risk patients. Future studies are needed to evaluate the long-term outcomes of TEVAR in similar cases and to further investigate the pathophysiological mechanisms underlying the simultaneous occurrence of IAA and liver abscess.