Aortic Endograft Infection: Diagnosis and Management

Vascular Graft Infections: Updates on a Challenging Problem

Vascular graft infections (VGI) pose a significant challenge in vascular surgery, characterized by substantial morbidity and mortality. This review delves into the epidemiology, pathogenesis, microbiology, risk factors, and clinical presentation of VGI. It highlights diagnostic criteria and methodologies, including imaging techniques and laboratory tests. Comprehensive management strategies, involving antimicrobial therapy, surgical intervention, and preventive measures, are discussed. Emphasis is placed on the multidisciplinary approach required for effective treatment, alongside emerging trends in VGI microbiology and innovative therapeutic options. This review article aims to provide a detailed understanding of VGI for improved clinical outcomes.

Mycobacterium bovis: An unusual cause of aortic graft infection

Mycobacterium has presented public health challenges since its inception, primarily affecting developing nations. Much less is known about M. bovis, a member of the mycobacterium family more frequently affecting zoonotic species. Infections postaortic aneurysm repair are rare, and few cases have reported infection secondary to the lesser-known mycobacterium member, M. bovis. Here, we present a case of aortic graft infection status-post aortic aneurysm repair secondary to M. bovis. We highlight the essential role multi-modal radiographic imaging played in establishing this diagnosis.

Misdiagnosis of Primary Iliac Aneurysmo-Colonic Fistula as a Submucosal Tumor Leading to Delayed Treatment: A Case Report

An aortoenteric fistula (AEF) is an uncommon cause of gastrointestinal bleeding that requires prompt diagnosis and intervention owing to its high mortality rate. Moreover, iliac aneurysmo-colonic fistula is an exceptionally infrequent presentation. We report a unique case of a 71-year-old male presenting with hematochezia, later diagnosed with a primary fistula between a common iliac artery aneurysm and the sigmoid colon. Initially, the patient was misdiagnosed as having a gastrointestinal stromal tumor, leading to delayed and emergent surgical intervention due to massive bleeding 2 days later. This case is particularly notable for its rarity, misinterpretation of the initial diagnosis, complicated surgical procedures, and development of complications including ischemic myopathy. This case highlights the criticality of accurate diagnosis with a high index of suspicion, significance of consultation with a vascular surgeon for vascular abnormalities, and importance of considering ischemic time in the sequence of surgical treatments to ensure timely and appropriate management.

Endoluminal rescue of false lumen graft deployment in TEVAR for type B aortic dissection: a case report and literature review

Background

Thoracic endovascular aortic repair (TEVAR) has increasingly become the preferred surgical intervention for Stanford type B aortic dissection (TBAD). The primary objective of this procedure is to seal the primary entry tear to promote positive aortic remodeling. However, the increased use of TEVAR has also led to a rise in surgical complications. Among these, the accidental deployment of the stent into the false lumen is a rare but serious complication that can result in aortic false lumen rupture and inadequate perfusion of abdominal organs.

Case summary

This case report described a 78-year-old man who presented to our hospital with sudden onset chest and back pain and was subsequently diagnosed with TBAD via aortic CTA. As conventional medical therapy failed to alleviate his chest pain, the patient underwent TEVAR. During the procedure, a complication arose when the distal end of the endograft was mistakenly deployed into the false lumen, leading to insufficient perfusion of the abdominal organs. Recognizing this issue intraoperatively, an additional endograft was promptly inserted at the distal end to reroute blood flow back to the true lumen of the aorta, thereby restoring visceral perfusion. Post-intervention, the patient's chest pain improved, and he was successfully discharged from the hospital.

Conclusion

Accidental deployment of a endograft into the false lumen during TEVAR is a rare but serious complication. Intraoperative angiography plays a crucial role in rapidly and accurately identifying this issue by detecting insufficient perfusion of abdominal organs. The use of intravascular ultrasound may help reduce the incidence of this complication. Endovascular repair is an effective emergency strategy to quickly redirect blood flow back to the true lumen, making it the preferred method for managing such emergencies.

Infected Abdominal Aortic Aneurysm Successfully Treated With Endovascular Aortic Repair and Antibiotics: A Case Report

Surgical treatment of infected aneurysms is problematic due to their high complication and mortality rates. Infected aortic aneurysms are at high risk of rupture and should be operated on as soon as possible after diagnosis. A 72-year-old female patient with a medical history of diabetes mellitus, hyperlipidemia, and hypertension presented with a fever of 38°C and back pain, without any apparent cause, in 2021. Her C-reactive protein (CRP) level increased to 20 mg/dL. Further evaluation with contrast-enhanced computed tomography (CT) revealed a low-density area with air pockets surrounding the abdominal aorta. The patient was diagnosed with native abdominal aortic infection and transferred to our hospital for treatment. The next day, endovascular aortic repair (EVAR) was performed using an Endurant stent graft (161682). Postoperatively, the patient was treated with antibiotics, and subsequently, blood infection was alleviated. Moreover, the CRP levels normalized. Follow-up contrast-enhanced CT showed resolution of the air pockets surrounding the abdominal aorta. The patient was discharged home on postoperative day 33. During her three-year follow-up as an outpatient, no recurrence of the infection was detected. While open surgical repair with prosthetic graft replacement is often the preferred treatment for infected abdominal aortic aneurysms, in select cases, as demonstrated by our patient, EVAR can be employed to prevent rupture, followed by antibiotic therapy to achieve infection control.

Which Gelatin and Antibiotic Should Be Chosen to Seal a Woven Vascular Graft?

Among the vascular prostheses used for aortic replacement, 95% are woven or knitted grafts from polyester fibers. Such grafts require sealing, for which gelatin (Gel) is most often used. Sometimes antibiotics are added to the sealant. We used gelatin type A (GelA) or type B (GelB), containing one of the three antibiotics (Rifampicin, Ceftriaxone, or Vancomycin) in the sealant films. Our goal was to study the effect of these combinations on the mechanical and antibacterial properties and the cytocompatibility of the grafts. The mechanical characteristics were evaluated using water permeability and kinking radius. Antibacterial properties were studied using the disk diffusion method. Cytocompatibility with EA.hy926 endothelial cells was assessed via indirect cytotoxicity, cell adhesion, and viability upon direct contact with the samples (3, 7, and 14 days). Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) were used to visualize the cells in the deep layers of the graft wall. "GelA + Vancomycin" and "GelB + vancomycin" grafts showed similar good mechanical characteristics (permeability~10 mL/min/cm2, kinking radius 21 mm) and antibacterial properties (inhibition zones for Staphilococcus aureus~15 mm, for Enterococcus faecalis~12 mm). The other samples did not exhibit any antibacterial properties. The cytocompatibility was good in all the tested groups, but endothelial cells exhibited the ability to self-organize capillary-like structures only when interacting with the "GelB + antibiotics" coatings. Based on the results obtained, we consider "GelB + vancomycin" sealant to be the most promising.