Primary Aortic Infections and Infected Aneurysms

Surgical treatment of a Salmonella-related infective native aortic aneurysm: A case report

Infective native abdominal aortic aneurysms are a life-threatening condition with a high mortality rate. We report the case of a 53-year-old male patient who presented with abdominal pain and fever. Laboratory results showed an elevated white blood cell count and C-reactive protein levels. Blood cultures detected Salmonella species, and computed tomography revealed a saccular abdominal aortic aneurysm. After 14 days of preoperative antibiotic therapy, the patient underwent a successful surgical bypass from the descending thoracic aorta, through the diaphragm and muscle layers of the anterior abdominal wall, to the bilateral common femoral arteries. The patient was discharged after 30 days of hospitalization and continued antibiotic treatment for another 30 days. Follow-up clinical evaluations and imaging studies showed good recovery and no signs of infection. This case highlights the importance of combining appropriate antibiotic therapy with surgical intervention in managing infective native aortic aneurysms. In particular, an extra-anatomical approach from the descending aorta can be a viable option in selected cases of infected aortic aneurysms, providing an effective means to achieve thorough debridement and prevent future graft infections.

Dissecting aortitis in a goat associated with Pasteurella multocida and Staphylococcus spp infection

Reports of primary cardiovascular disease in goats are rare and most commonly include ventricular septal defect, valvular endocarditis, traumatic pericarditis, ionophore poisoning and nutritional cardiomyopathies. We now report the pathological findings in a 67 kg, 6-year-old, adult female Boer goat that presented with neurological signs (ie, head pressing, unsteadiness and paddling) and hyperthermia 2 days prior to death. Lack of therapeutic response to meloxicam and penicillin‒streptomycin and poor prognosis led to euthanasia of the animal. At necropsy, the main findings included severe aortic dissection with luminal thrombosis and stenosis, and pulmonary congestion and oedema. Histological examination of the aorta revealed severe chronic granulomatous and fibrosing dissecting aortitis with mineralization. Bacterial culture of the affected aortic segment resulted in isolation of a profuse growth of Pasteurella multocida and a moderate growth of Staphylococcus spp. Histopathological findings in the central nervous system were consistent with neurolisteriosis.

A review on the deeper understanding of inflammation and infection of the thoracic aorta

OBJECTIVE

To review the current literature regarding infection and inflammation of the thoracic aorta and to summarise its aetiologies, pathogenesis and clinical presentation. Additionally, the authors sought to compare diagnostic methods and to analyse the different management options.

METHOD

A comprehensive electronic search using PubMed, MEDLINE, Scopus and Google Scholar was conducted to find relevant journal articles with key search terms including: 'aortitis', 'thoracic aortic infection' and 'surgical management of infected thoracic aortic aneurysms'. Prominent publications from 1995 till present (2021) were analysed to achieve a deeper understanding of thoracic aorta infection and inflammation, and the information was then collated to form this review.

RESULTS

The literature review revealed that infectious causes are more prominent than non-infectious causes, with Gram positive bacteria such as Staphylococcus, Enterococcus and Streptococcus accounting for approximately 60% of the infections. The authors also noted that Staphylococcus Aureus was associated with poorer outcomes. Key diagnostic tools include MRI and multi-slice CT imaging, which are useful imaging modalities in defining the extent of the disease thus allowing for planning surgical intervention. Surgical intervention itself is extremely multifaceted and the rarity of the condition means no large-scale comparative research between all the management options exists. Until more large-scale comparative data becomes available to guide treatment, the optimal approach must be decided on a case-by-case basis, considering the benefits and drawback of each treatment option.

CONCLUSION

A high index of suspicion and a comprehensive history is required to effectively diagnose and manage infection and inflammation of the thoracic aorta. Differentiating between infectious and inflammatory cases is crucial for management planning, as infectious causes typically require antibiotics and surgical intervention. Over the years, the post treatment results have shown significant improvement due to earlier diagnosis, advancement in surgical options and increasingly specific microbial therapy.

Association Between Aortic Aneurysm and Aortic Dissection With Fluoroquinolones Use in Patients With Urinary Tract Infections: A Population-Based Cohort Study

Background Fluoroquinolones are first-line antibiotics recommended for the treatment of complicated urinary tract infections (UTIs), with frequent reports of adverse effects of aortic aneurysm (AA) and aortic dissection (AD). We examined whether fluoroquinolones can increase the risk of AA and AD in patients with UTIs in the Taiwanese population. Methods and Results We used the National Health Insurance Research Database to identify patients diagnosed with UTIs under single antibiotic treatment of fluoroquinolones and first-, second-, or third-generation cephalosporins. An AA and AD diagnosis within a year constituted the study event. Multivariable analysis with a multiple Cox regression model was applied for comparing the hazard risk of AA and AD between fluoroquinolones and first- or second-generation cephalosporins. Propensity score matching was performed to reduce the potential for bias caused by measured confounding variables. Among 1 249 944 selected patients with UTIs, 28 568 patients were assigned to each antibiotic group after propensity score matching. The incidence of AA and AD was not significantly different between the fluoroquinolones and first- or second-generation cephalosporins (adjusted HR [aHR], 0.86 [95% CI, 0.59-1.27]). However, the mortality increased in the fluoroquinolones group (aHR, 1.10 [95% CI, 1.04-1.16]). Conclusions Compared with first- or second-generation cephalosporins, fluoroquinolones were not associated with increased risk of AA and AD in patients with UTI. However, a significant risk of mortality was still found in patients treated with fluoroquinolones. The priority is to control infections with adequate antibiotics rather than exclude fluoroquinolones considering the risk of AA and AD for patients with UTI.

Vascular Graft Infections: An Overview of Novel Treatments Using Nanoparticles and Nanofibers

Vascular disease in elderly patients is a growing health concern, with an estimated prevalence of 15–20% in patients above 70 years old. Current treatment for vascular diseases requires the use of a vascular graft (VG) to revascularize lower or upper extremities, create dialysis access, treat aortic aneurysms, and repair dissection. However, postoperative infection is a major complication associated with the use of these VG, often necessitating several operations to achieve complete or partial graft excision, vascular coverage, and extra-anatomical revascularization. There is also a high risk of morbidity, mortality, and limb loss. Therefore, it is important to develop a method to prevent or reduce the incidence of these infections. Numerous studies have investigated the efficacy of antibiotic- and antiseptic-impregnated grafts. In comparison to these traditional methods of creating antimicrobial grafts, nanotechnology enables researchers to design more efficient VG. Nanofibers and nanoparticles have a greater surface area compared to bulk materials, allowing for more efficient encapsulation of antibiotics and better control over their temporo-spatial release. The disruptive potential of nanofibers and nanoparticles is exceptional, and they could pave the way for a new generation of prosthetic VG. This review aims to discuss how nanotechnology is shaping the future of cardiovascular-related infection management.

The Microbiology of Infective Native Aortic Aneurysms in a Population-Based Setting

OBJECTIVE

The aim was to describe the microbiology of surgically treated infective native (mycotic) aortic aneurysms (INAAs), and associated survival and development of infection-related complications (IRCs).

METHODS

Data were pooled from 2 nationwide studies on surgically treated patients with INAAs in Sweden, between 1994 - 2016. Patients were grouped and analyzed according to culture results: 1) Staphylococcus aureus, 2) Streptococcus species (sp.), 3) Salmonella sp., 4) Enterococcus sp., 5) Gram-negative intestinal bacteria, 6) Other sp. (all other species found in culture), and 7) Negative cultures.

RESULTS

A sum of 182 patients were included, mean age 71 years (standard deviation; SD: 8.9). The median follow-up was 50.3 months (range 0 - 360). 128 (70.3%) patients had positive blood and/or tissue culture; Staphylococcus aureus n = 38 (20.9%), Streptococcus sp. n = 37 (20.3%), Salmonella sp. n = 19 (10.4%), Enterococcus sp. n = 16 (8.8%), Gram-negative intestinal bacteria n = 6, (3.3%), Other sp. n = 12 (6.6%) and Negative cultures n = 54 (29.7%). The estimated survival for the largest groups at 2-years after surgery was: Staphylococcus aureus 62% (95% Confidence interval 53.9 - 70.1), Streptococcus sp. 74.7% (67.4 - 82.0), Salmonella sp. 73.7% (63.6 - 83.8), Enterococcus sp. 61.9% (49.6 - 74.2), and Negative cultures 89.8% (85.5 - 94.1), P = .051. There were 37 IRCs (20.3%), and 19 (51.4%) were fatal, the frequency was insignificant between the groups. The majority of IRCs, 30/37 (81%), developed during the first postoperative year.

CONCLUSION

In this assessment of microbiological findings of INAAs in Sweden, 50% of the pathogens were Staphylococcus aureus, Streptococcus sp., or Salmonella sp.. The overall 20%-frequency of IRCs, and its association with high mortality, motivates long-term antibiotic treatment regardless of microbial findings.

Association of Infections and Use of Fluoroquinolones With the Risk of Aortic Aneurysm or Aortic Dissection

IMPORTANCE

Prior observational studies have suggested that fluoroquinolone use may be associated with more than 2-fold increased risk of aortic aneurysm or aortic dissection (AA/AD). These studies, however, did not fully consider the role of coexisting infections and the risk of fluoroquinolones relative to other antibiotics.

OBJECTIVE

To estimate the risk of AA/AD associated with infections and to assess the comparative risk of AA/AD associated with fluoroquinolones vs other antibiotics with similar indication profiles among patients with the same types of infections.

DESIGNS, SETTINGS, AND PARTICIPANTS

This nested case-control study identified 21 651 176 adult patients from a nationwide population-based health insurance claims database from January 1, 2009, to November 30, 2015. Each incident case of AA/AD was matched with 10 control individuals by age, sex, and follow-up duration in the database using risk-set sampling. Analysis of the data was conducted from April 2019 to March 2020.

EXPOSURES

Infections and antibiotic use within a 60-day risk window before the occurrence of AA/AD.

MAIN OUTCOMES AND MEASURES

Conditional logistic regression was used to estimate the odds ratios (ORs) and 95% CIs comparing infections for which fluoroquinolones are commonly used with no infection within a 60-day risk window before outcome occurrence, adjusting for baseline confounders and concomitant antibiotic use. The adjusted ORs comparing fluoroquinolones with antibiotics with similar indication profiles within patients with indicated infections were also estimated.

RESULTS

A total of 28 948 cases and 289 480 matched controls were included (71.37% male; mean [SD] age, 67.41 [15.03] years). Among these, the adjusted OR of AA/AD for any indicated infections was 1.73 (95% CI, 1.66-1.81). Septicemia (OR, 3.16; 95% CI, 2.63-3.78) and intra-abdominal infection (OR, 2.99; 95% CI, 2.45-3.65) had the highest increased risk. Fluoroquinolones were not associated with an increased AA/AD risk when compared with combined amoxicillin-clavulanate or combined ampicillin-sulbactam (OR, 1.01; 95% CI, 0.82-1.24) or with extended-spectrum cephalosporins (OR, 0.88; 95% CI, 0.70-1.11) among patients with indicated infections. The null findings for fluoroquinolone use remained robust in different subgroup and sensitivity analyses.

CONCLUSIONS AND RELEVANCE

These results highlight the importance of accounting for coexisting infections while examining the safety of antibiotics using real-world data; the findings suggest that concerns about AA/AD risk should not deter fluoroquinolone use for patients with indicated infections.

Clinical experience of positron-emission tomography in infective aortic disease

Background

Fluorine-18-fluorodeoxyglucose positron-emission tomography with computed tomography has revolutionized medical diagnosis by adding functional activity to anatomic imaging. We report our experience with this technique in patients with mycotic aortic pathology and aortic vascular graft infection.

Methods

We conducted a retrospective review of a prospective database of patients who underwent 18F-fluorodeoxyglucose positron-emission tomography with computed tomography for suspected infective aortic disease. From 2012 to 2016, 13 patients underwent 18F-fluorodeoxyglucose positron-emission tomography. Of these, 9 (69%) had a vascular graft infection (5 infrarenal aorta, 1 para-visceral, 2 descending, and 1 arch; 2 had previous open surgery and 7 had endovascular interventions) and 4 (31%) had a mycotic aneurysm (2 aortic arch, 1 infrarenal aorta, and 1 distal aorta and common iliac; 3 had endografts). The indications for imaging, location of pathology, 18F uptake, and clinical outcomes were analyzed.

Results

Eight (62%) patients had a single scan and 5 (38%) had serial scans performed. Among the 5 patients who had serial imaging, 3 showed decreased 18F uptake and 2 had increased uptake. Only one patient underwent subsequent endograft removal; the others were treated with lifelong antibiotics. There were 5 (38%) deaths on follow-up.

Conclusion

18F-fluorodeoxyglucose positron-emission tomography with computed tomography could be a valuable adjunct in the diagnosis and surveillance of patients with aortic infection. Serial scans may be useful for monitoring disease activity and response to antibiotic therapy.

Kidney Salvage During Surgical Treatment of a Pararenal Mycotic Aortic Aneurysm

Mycotic abdominal aortic aneurysms although rare are accompanied by an extensive risk of morbidity and mortality. Surgical treatment is challenging, but it offers the only chance of survival. Extra-anatomic aortic reconstruction through uninfected tissues is feasible, providing a durable therapeutic option in the presence of severe infection.

Extra-Anatomic Bypass Operation for an Infected Aortic Arch Aneurysm with Broad Mediastinal Abscess: A Case Report

We encountered an informative case of infected aortic arch aneurysm. The proximal descending aorta, left common carotid artery, and left subclavian artery were severely involved in an abscess; thus, typical in situ reconstruction of the arch was considered impossible. Therefore, to secure more distal branches appropriate for anastomosis, a modified extra-anatomic arch repair was performed through additional incisions. The patient developed renal and respiratory failure and died of septicemia five and a half months after the operation. However, postoperative computed tomograms demonstrated that the abscess had disappeared.

Chronic Contained Abdominal Aortic Aneurysm Rupture Mimicking Vertebral Spondylodiscitis: A Case Report

A 63-year-old Caucasian male presented with a 4-month history of low back pain associated with bilateral intermittent claudication. A contrast enhanced CT scan demonstrated a 4 cm abdominal aortic aneurysm (AAA), along with severe bilateral aorto-iliac disease, a right psoas collection, and extensive vertebral erosion. An MRI of the lumbar spine suggested spondylodiscitis at L4-L5. After an unsuccessful and prolonged course of antibiotics, a decision was ultimately made to repair the aneurysm and bypass the aorto-iliac disease. Intra-operatively, a chronic contained rupture (CCR) involving the posterior aortic wall was encountered and repaired with an aorto-bifemoral bypass graft.

Management of the infected aortoiliac aneurysms

PURPOSE

We have reviewed ruptured and nonruptured infected aortoiliac aneurysms to study the clinical presentation, management and eventual outcome of patients managed with in situ prostheses, axillofemoral prostheses grafts and endovascular reconstruction.

DESIGN

A retrospective chart review of 16 cases treated at a single institution.

METHODS

From January 2007 to March 2008, a total of 93 patients with aortoiliac aneurysms underwent surgical repair at our institution. Among these, 16 patients (17.2%) were shown to be infected aneurysms of the infrarenal (n = 6), juxtarenal (n = 2), and pararenal aorta (n = 1); the others were 5 common, 1 external, and 1 internal iliac arteries. Fourteen patients were male and 2 were female with the mean age of 66 years (range, 45-79). In all cases, the diagnosis was confirmed by abdominal computed tomography and empirical parenteral antibiotics were administered at least 1 week, unless in patients need emergency operations. At the time of an operation, all were saccular and were classified as primary infected aortoiliac aneurysms. Thirteen patients had surgical debridement with in situ graft interposition and omental wrapping, 2 underwent aneurysm exclusion and extra-anatomic (axillo-femoral) bypass, 1 underwent aneurysmectomy of left external iliac artery and polytetrafluoroethylene (PTFE) graft interposition, and 1 underwent endovascular exclusion. The parenteral antibiotics were continued in the postoperative period for 4-6 weeks. Chronic renal disease was present in 37.5% (6/16), with diabetes mellitus present in 31.25% (5/16). The most common pathogen was Salmonella sp. (n = 6) and E. coli (n = 5). Thirty-seven percent (6/16) of the patients presented late, with a 37.5% (6/16) incidence of ruptured (4 contained, 2 free ruptured) that needed emergency surgery.

RESULTS

Disease-specific mortality was 31.25% (5/16). The 30-day mortality rate of ruptured cases is high 67% (4/6), because patients present late in the course of the disease. One patient who underwent aneurysm exclusion and extra-anatomic (axillo-femoral) bypass died 6 months later from burst aortic stump. Salmonella and E. coli are the most common pathogens.

CONCLUSIONS

Early diagnosis followed by surgical intervention with proper antibiotic coverage provides the best results. Mortality rate was still high in patients with sepsis and rupture. An in situ graft interposition and omental wrapping is a safe option for revascularization of infected aneurysms of the iliac arteries and infrarenal aorta.

Ruptured tuberculous false aneurysm of the abdominal aorta: a case report

Tuberculous false aneurysm of the aorta is rare and has an unpredictable complication of aneurysm rupture. We report a case of a 32-year old woman who was referred to the Department of Vascular Surgery, Avicenne Hospital for severe abdominal pain. Chest x-ray revealed miliary tuberculosis. Contrast enhanced computed tomography (CT) scan showed a false aortic aneurysm involving the juxtarenal aorta. Antituberculous treatment was started because of high presumption of tuberculosis. Five days later, the patient presented with symptoms of aneurysm rupture. She underwent an emergency a surgical resection of the aneurysm with repair of the aortic wall defect by a Dacron Silver patch. The histopathologic examination of the aortic wall showed features of tuberculosis.

Two-stage Surgery for Double Infected Aneurysms in the Infrarenal Abdominal and Descending Thoracic Aorta

A 61-year-old man complaining of lumbago and high-grade fever was admitted to our institution. Computed tomography (CT) revealed a saccular aneurysm in the infrarenal abdominal aorta and blood culture results were positive for Streptococcus pneumoniae. He was diagnosed with infected abdominal aortic aneurysm, and antibiotic therapy was initiated. Follow-up CT demonstrated a rapidly-enlarging abdominal aortic aneurysm and a newly-developed descending thoracic aortic aneurysm. For this case, two-stage surgery consisting of extra-anatomical bypass and in-situ reconstruction using rifampicin-soaked Dacron graft was performed after an interval of 37 days. The patient was discharged 14 days after the second surgery without any complications.