Treatment strategies for aortic and peripheral prosthetic graft infection

A case series of image-guided percutaneous drainage of abdominal aortic graft infection as bridge therapy

INTRODUCTION

Aortic graft infection (AGI) is a rare complication following endovascular aneurysm repair and is associated with substantial morbidity and mortality. The traditional management of AGI is intravenous antibiotic therapy and surgical explantation. In this case series, percutaneous drainage was used as a bridge therapy in the treatment of AGI.

METHODS

We report two cases, 78-year-old male and 57-year-old female, in whom image-guided percutaneous drainage was used to treat AGI in two contrasting contexts. Informed consent was obtained from both cases/relatives for publication.

RESULTS

Both cases underwent successful percutaneous drainage of AGI utilized as a bridge therapy before definitive surgical reconstruction and graft explantation. Each patient had a different outcome. In the first case, the patient's comorbidities and severe disease state could not be overcome, resulting in his death. The second patient benefitted from the percutaneous drainage by allowing her more time ameliorate her malnutrition before definitive surgery.

CONCLUSION

Data on the outcomes of percutaneous drainage of AGI is limited. The successful procedure described in this case series emphasizes the need to conduct more research to evaluate the safety and efficacy of this treatment approach before the surgical explantation.

Conservative Management First Strategy in Aortic Vascular Graft and Endograft Infections

OBJECTIVE

The aim of this study was to describe and present the outcomes of a specific treatment protocol for aortic vascular graft and endograft infections (VGEIs) without explantation of the infected graft.

METHODS

This was a retrospective, observational single centre cohort study carried out between 2012 and 2022 at a tertiary hospital. An aortic VGEI was defined according to the Management of Aortic Graft Infection Collaboration (MAGIC) criteria. Fitness for graft excision was assessed by a multidisciplinary team and included an evaluation of the patient's general condition, septic status, and anatomical complexity. Antimicrobial treatments were individualised. The primary outcome was survival at the last available follow up; secondary outcomes were antimicrobial treatment duration, infection eradication, treatment failure despite antimicrobial treatment, and the development of aortic fistulation.

RESULTS

Fifty patients were included in the study, of whom 42 (84%) had had previous endovascular repair. The median patient age was 72 years (range 51 - 82 years) and median duration of treatment with antimicrobials was 18 months (range 1 - 164 months). Kaplan-Meier analysis estimated the 30 day survival to be 98% (95% confidence interval [CI] 96 - 100), the one year survival rate to be 88% (95% CI 83.4 - 92.6), and the three year survival rate to be 79% (95% CI 72.7 - 84.7). Twenty-four (48%) patients were able to discontinue antibiotic treatment after a median of 16 months (range 4 - 81 months). When categorised according to infected graft location, deaths occurred in four (40%) patients with thoracic, two (40%) with paravisceral, seven (30%) with infrarenal VGEIs, and in one (25%) patient with an aorto-iliac VGEI; no (0%) patient with a thoraco-abdominal VGEI died.

CONCLUSION

Identifying the microbiological aetiology in patients with aortic VGEI enables individualised, specific antibiotic treatment, which may be useful in patients with a VGEI excluded from surgery. This single centre retrospective analysis of patients with VGEIs without fistula selected for conservative treatment suggests that conservative management of aortic VGEIs with targeted antibiotic therapy without graft excision is potentially effective, and that antimicrobial treatment will not necessarily be needed indefinitely.

Case report: Vascular graft infection due to Aspergillus species presenting with recurrent vascular occlusion

Background

An aortic graft implantation is an effective therapeutic method for various aortic diseases. However, it is known that sometimes these implanted grafts can be the foci of infections. Here we report a rare case of graft infection that presented multiple embolisms of aortic branches and peripheral organs.

Case presentation

A 63-year-old Japanese woman with a history of aortic graft implantation presented with occlusions of large arteries in different loci and time points, with elevation of non-specific inflammatory markers. Thoracic contrast-computed tomography (CT) captured vegetation in the descending aortic graft and the [18F]fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) showed accumulation of FDG in the same site, suggesting a graft infection. Despite all these suspicious findings, repeated blood culture examinations never detected any microorganisms. A diagnosis of Aspergillus graft infection was made based on an elevated serum β-D glucan (βDG) and a positive Aspergillus galactomannan (GM) antigen test. The patient subsequently had surgery with replacement of the descending aortic graft and anti-fungal drugs were instituted with significant improvement noted.

Conclusion

In the present case, the patient’s specific feature in the anatomical vascular construction, past operation, and basal fundamental diseases collaboratively contributed to the pathogenesis of the present infection. It is important to recognize the risk of graft infection and conduct imaging studies when indicative symptoms emerge. The negativity in blood culture studies often makes detection of pathogenic microbes extremely difficult. This case suggests that non-cultural tests such as bDG and GM can be useful for diagnosis and starting appropriate anti-fungal drugs in the early stages.

Percutaneous Drainage for Aortic Graft Infection Post-aneurysm Repair: A Viable Option?

Purpose

Non-operative management of aortic graft infection is usually only considered in a palliative context. We describe the safety, efficacy, and clinical outcomes of percutaneous drainage of aortic graft infections (AGI) following either open or endovascular repair of aneurysmal disease.

Methods

Twelve consecutive patients (11 males, 1 female, mean age 72.7 ± 10.3 years, age range 52-88 years) between January 2010-July 2020 who underwent percutaneous drain insertion in either an infected aortic sac or periaortic abscess cavity following endovascular or open surgical graft repair were identified. Patient and procedural characteristics as well as clinical outcomes were determined.

Results

Of the 12 patients who underwent percutaneous drain insertion, five (41.7%) had undergone open abdominal aneurysm repair, one (8.3%) open thoracoabdominal aneurysmal repair, and six (50%) endovascular abdominal aneurysm repairs. Drain size ranged from 10-20 French. All were inserted under ultrasound (US), computed tomography (CT), and/or fluoroscopic guidance. Median duration of drain placement was 55.2 days (range 3-174). Five patients (41.7%) had the drain in place as a stabilizing bridge until or after definitive surgical explantation and aortic reconstruction. Seven patients (58.3%) were managed with drain placement and antibiotic therapy without surgical intervention. Six (50%) were alive at the most recent time of follow-up (median, 732 days, range 166-1650 days). Three patients (25%) died during follow-up with causes including erosion of aortic reconstruction into sigmoid colon, unrelated chronic obstructive pulmonary disease exacerbation, and severe clostridium difficile colitis and pseudomonal pneumonia (median 1244 days, range 992-1597 days). Three (25%) patients were lost to follow-up. No drain-related complications were noted.

Conclusion

Percutaneous drainage of AGI following endovascular or open aneurysm repair is a safe and viable management option either as a temporizing measure as a bridge to surgical graft explantation or as a non-surgical therapy for long term management.

Does washing medical devices before and after use decrease bacterial contamination?: An in vitro study

ABSTRACT

Surface treatment of medical devices may be a way of avoiding the need for replacement of these devices and the comorbidities associated with infection. The aim of this study was to evaluate whether pre- and postcontamination washing of 2 prostheses with different textures can decrease bacterial contamination.The following microorganisms were evaluated: Staphylococcus aureus, Staphylococcus epidermidis, Proteus mirabilis and Enterococcus faecalis. Silicone and expanded polytetrafluoroethylene vascular prostheses were used and divided into 3 groups: prostheses contaminated; prostheses contaminated and treated before contamination; and prostheses contaminated and treated after contamination. Treatments were performed with antibiotic solution, chlorhexidine and lidocaine. After one week of incubation, the prostheses were sown in culture medium, which was incubated for 48 hours. The area of colony formation was evaluated by fractal dimension, an image analysis tool.The antibiotic solution inhibited the growth of S epidermidis and chlorhexidine decrease in 53% the colonization density for S aureus in for both prostheses in the pre-washing. In postcontamination washing, the antibiotic solution inhibited the growth of all bacteria evaluated; there was a 60% decrease in the colonization density of S aureus and absence of colonization for E faecalis with chlorhexidine; and lidocaine inhibited the growth of S aureus in both prostheses.Antibiotic solution showed the highest efficiency in inhibiting bacterial growth, especially for S epidermidis, in both washings. Lidocaine was able to reduce colonization by S aureus in post-contamination washing, showing that it can be used as an alternative adjuvant treatment in these cases.

Efficacy of Computed Tomography-Guided Catheter Drainage as the Initial Intervention and of Omentopexy as the Staged Surgery for a Prosthetic Graft Infection of Very Late Onset

On the basis of computed tomography (CT) examination, a prosthetic graft infection of very late onset was suspected in a 72-year-old man who had undergone replacement of an bifurcated prosthetic graft 6 years earlier because of an abdominal aortic aneurysm and bilateral common iliac artery aneurysms. Emergency CT-guided needle aspiration was performed, and analysis of directly aspirated fluid confirmed the rapid diagnosis. Instead of conventional emergency surgery, CT-guided catheter drainage was the initial treatment and led to the gradual improvement of symptoms and laboratory data. Elective staged surgery was performed later to examine the cavity around the prosthetic graft. The cavity was then filled with in-situ omentum. Thus, CT-guided catheter drainage as the initial treatment and following omentopexy as the staged surgery avoided the need for highly invasive conventional surgery.