Management of a Mycotic Aneurysm in a Patient with COVID-19: A Case Report

The aim of this paper is to share our experience in managing a patient with Klebsiella pneumoniae mycotic abdominal aortic aneurysm who was also infected with COVID-19. A 69-year-old male was transferred to our hospital for the management of an infra-renal mycotic abdominal aortic aneurysm. During his hospital course, the patient contracted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). He was intubated due to respiratory distress. Over a short period, his mycotic aneurysm increased in size from 2.5 cm to 3.9 cm. An emergency repair of his expanding aneurysm was achieved using our previously described protocol of coating endovascular stents with rifampin. The patient was managed with a rifampin-coated endovascular stent graft without any major complications. Postoperatively, the patient did not demonstrate any neurological deficits nor any vascular compromise. He remained afebrile during his postoperative course and was extubated sometime thereafter. He was then transferred to the ward for additional monitoring prior to his discharge to a rehab hospital while being on long-term antibiotics. During his hospital stay, he was monitored with serial ultrasounds to ensure the absence of abscess formation, aortic aneurysm growth or graft endoleak. At 6 weeks after stent graft placement, he underwent a CT scan, which showed a patent stent graft, with a residual sac size of 2.5 cm without any evidence of abscess or endoleak. Over a follow-up period of 180 days, the patient remained asymptomatic while remaining on long-term antibiotics. Thus, in patients whose surgical risk is prohibitive, endovascular stent grafts can be used as a bridge to definitive surgical management.

Remote endarterectomy to remove infected Viabahn stent-graft

Infection of peripheral arterial vascular grafts and stent-grafts represents a complex surgical scenario, with a number of proposed management strategies. Surgical removal of infected material with adjunctive arterial reconstruction is often required. However, surgical removal is often difficult and complex. This case study demonstrates an infected Viabahn stent-graft between the external iliac artery and the superficial femoral artery, with arterial autolysis of the common femoral artery and proximal superficial femoral artery, in which a hybrid technique combining remote endarterectomy and surgical debridement was used to remove the infected stent-graft.

A case of Infective Native (Abdominal) Aortic Aneurysm Caused by Streptococcus Agalactiae: An Updated Literature Review Based on New Nomenclature

The management of abdominal aortic aneurysms (AAA) has evolved significantly with the advent of endovascular strategies. Thus, there has been a decline in the number of open AAA repairs once an endovascular option is available. There have also been reports of successful endovascular management of infective native aortic aneurysms (INAA)¹, previously called mycotic aneurysms². The rarity of this condition makes its management a challenging one as there are no standard guidelines. The European Society of Vascular Surgery has suggested that the nomenclature be changed from mycotic aneurysms as this can be misleading to standardise reporting¹. The authors' present a case of a 67-year old male who presented during the peak of the Corona Virus pandemic with constitutional gastrointestinal symptoms. He was subsequently diagnosed with an INAA and successfully managed with open Neo-Aorto Iliac System reconstruction with a homograft³. The report highlights various strategies used in the surgical approach and their benefits in the management of INAA. Furthermore, a literature review of Streptococcus (Streptococcus agalactiae) species as a rare cause of INAA and how these cases were managed are also highlighted.

A Bail Out Solution for an Urgent Situation: Endovascular Exclusion and Embolization of an Infected Femoral Pseudoaneurysm

PURPOSE

The aim of this study is to show the utility of the combination of thrombin and endograft to solve an urgent situation related to femoral infections.

CASE

We present the case of a 91-year-old female patient who underwent a femoral endarterectomy and superficial femoral artery angioplasty and developed a surgical site infection. She was readmitted to the hospital because of bleeding and was operated to suture the femoral patch and to do a plasty of sartorius muscle. Six days after the last intervention a femoral pulsatile mass was noted, and the computed tomography showed a big femoral pseudoaneurysm. Taken again to the theater and via a contralateral puncture a viabahn covered endograft was deployed from the external iliac artery to the yet diseased but patent femoral superficial femoral artery and the pseudoaneurysm was punctured, emptied, and filled with thrombin. The patient was discharged 2 weeks after the last procedure and lived for 10 months (she died because of a nonvascular related cause) with a patent graft and with healed lesions.

CONCLUSIONS

In this case the endovascular solution was a definitive solution in a very old patient with several comorbidities.

Methicillin-resistant Staphylococcus aureus portends a poor prognosis after endovascular repair of mycotic aortic aneurysms and aortic graft infections

OBJECTIVE

Mycotic aortic aneurysms and aortic graft infections (aortic infections [AIs]) are rare but highly morbid conditions. Open surgical repair is the "gold standard" treatment, but endovascular repair (EVR) is increasingly being used in the management of AI because of the lower operative morbidity. Multiple organisms are associated with AI, and bacteriology may be an important indication of mortality. We describe the bacteriology and associated outcomes of a group of patients treated with an EVR-first approach for AI.

METHODS

All patients who underwent EVR for native aortic or aortic graft infections between 2005 and 2016 were retrospectively reviewed. Primary end points were 30-day mortality and overall mortality. The primary exposure variable was bacteria species. Logistic regression analysis was used to determine association with mortality. Kaplan-Meier survival analysis was used to estimate survival.

RESULTS

A total of 2038 EVRs were performed in 1989 unique and consecutive patients. Of those, 27 patients had undergone EVR for AI. Thirteen presented ruptured (48%). Eighteen (67%) were hemodynamically unstable. Ten had a gastrointestinal bleed (37%), whereas others presented with abdominal pain (33%), fever (22%), chest or back pain (18.5%), and hemothorax (3.7%). Twenty patients had a positive blood culture (74%), with the most common organism being methicillin-resistant Staphylococcus aureus (MRSA) isolated in 37% (10). Other organisms were Escherichia coli (3), Staphylococcus epidermidis (2), Streptococcus (2), Enterococcus faecalis (1), vancomycin-resistant Enterococcus (1), and Klebsiella (1). Thirteen patients had 4 to 6 weeks of postoperative antibiotic therapy, six of whom died after therapy. Fourteen were prescribed lifelong therapy; 10 died while receiving antibiotics. On univariate analysis for mortality, smoking history (P = .061) and aerodigestive bleeding on presentation (P = .109) approached significance, whereas MRSA infection (P = .001) was strongly associated with increased mortality. On multivariate analysis, MRSA remained a strong, independent predictor of mortality (adjusted odds ratio, 93.2; 95% confidence interval, 1.9-4643; P = .023). Overall 30-day mortality was 11%, all MRSA positive. At mean follow-up of 17.4 ± 28 months, overall mortality was 59%. Overall survival at 1 year, 3 years, and 5 years was 49%, 31%, and 23%. Kaplan-Meier survival analysis demonstrated that MRSA-positive patients had a significantly lower survival compared with other pathogens (1-year, 20% vs 71%; 5-year, 0% vs 44%; P = .0009).

CONCLUSIONS

In our series of AI, the most commonly isolated organism was MRSA. MRSA is highly virulent and is associated with increased mortality compared with all other organisms, regardless of treatment. Given our results, EVR for MRSA-positive AI was not a durable treatment option.

Isolated mycotic hypogastric artery aneurysm

Isolated iliac artery aneurysms are rare and commonly associated with aortic aneurysms. Hypogastric artery aneurysms (HAAs) are exceptionally rare. The general approach to HAAs has been exclusion and bypass, although when this is complicated by mycotic disease, endovascular techniques can provide unique approaches to management. We present the case of a patient with a mycotic HAA treated with endovascular coil and exclusion followed by aortic to external iliac artery bypass with cadaveric conduit.

Endovascular Repair of Three Concurrent Mycotic Pseudoaneurysms

INTRODUCTION

Mycotic pseudoaneurysm has traditionally been repaired surgically with excision of the infected artery and revascularization via extra-anatomical or in situ bypass. There have been reports of endovascular repair for high-risk patients for formal surgical repair. We present a case of a patient with 3 large pseudoaneurysms arising from the right subclavian artery, descending thoracic aorta, and right popliteal artery treated with endovascular and hybrid intervention.

CASE

A 74-year-old male with remote history of coronary artery bypass graft and recent sternoclavicular joint abscess developed 3 concurrent pseudoaneurysms arising from the right subclavian artery, distal descending thoracic aorta, and right popliteal artery. He underwent right axillary to common carotid bypass with endovascular stent graft placement in the distal innominate and proximal subclavian artery, and subsequently had thoracic endovascular aortic repair and right popliteal stent graft. Four months later, he presented with hemoptysis due to compression of the lung secondary to the pseudoaneurysm. He underwent right anterior thoracotomy and debridement of the pseudoaneurysm. Patient recovered from the procedure and discharged.

CONCLUSION

Endovascular repair of mycotic pseudoaneurysm is an acceptable alternative for high-risk patients. Even when open approach became necessarily, endovascular stent graft decreased blood loss and morbidity.

Optimization of rifampin coating on covered Dacron endovascular stent grafts for infected aortic aneurysms

OBJECTIVE

In the treatment of an infected aorta, open repair and replacement with a rifampin-impregnated Dacron vascular graft decrease the risk of prosthetic graft infections, with several protocols available in the literature. We hypothesize that the same holds true for endovascular aneurysm repair, and after studying and optimizing rifampin solution concentration and incubation period to maximize the coating process of rifampin on Dacron endovascular stent grafts (ESGs), we propose a rapid real-time perioperative protocol.

METHODS

Several prepared rifampin solutions, including a negative control solution, were used to coat multiple triplicate sets of Dacron endovascular aortic stent grafts at different but set incubation periods. Rifampin elution from the grafts was studied by spectroscopic analysis. Once an optimized solution concentration and incubation time were determined, the elution of rifampin over time from the graft and the graft's surface characteristics were studied by ultraviolet-visible spectroscopy and atomic force microscopy.

RESULTS

All coated ESGs with any concentration of prepared rifampin solution, regardless of incubation time, immediately demonstrated a visible bright orange discoloration and subsequently after elution procedures returned to the original noncolored state. At the 25-minute incubation time (standard flush), there was no statistical difference in the amount of rifampin coated to the ESGs with 10-mg/mL, 30-mg/mL, and 60-mg/mL solutions (0.06 ± 0.01, 0.07 ± 0.05, and 0.044 ± 0.01, respectively; P > .05). This was also true for a 10-minute incubation time (express flush) of 10-mg/mL and 60-mg/mL rifampin solution concentrations (0.04 ± 0.007 and 0.066 ± 0.014, respectively; P = .22). The elution-over-time of coated rifampin ESG, although not statistically significant, did seem to plateau and to reach a steady state by 50 hours and was confirmed by surface characteristics using atomic force microscopy.

CONCLUSIONS

Having studied two variables of rifampin coating techniques to Dacron ESGs, the authors propose a rapid real-time perioperative coating protocol by using a 10-mg/mL rifampin solution for a 10-minute incubation period. As rifampin loosely binds to Dacron ESGs by weak intermolecular forces, a rifampin-coated ESG would need to be inserted in a timely fashion to treat the diseased aorta and to deliver its antibiotic affect. A rapid perioperative coating protocol followed by immediate deployment makes our proposed technique especially useful in an urgent and unstable clinical scenario.

Multilevel Mycotic Aneurysms Due to Salmonella Infection: Case Report and Review of the Literature

Infected or mycotic aneurysms (MAs) of the aorta and adjacent arteries are rare and difficult to treat. We report a unique case of a Salmonella serotype enteritidis-induced rapidly expanding aortic and iliac pseudoaneurysm during preoperative workup. Based on the presented case, we postulate that the agressive nature of Salmonella enteritidis MAs should not be underestimated. If postponed intervention is chosen and the patient is managed conservatively with antibiotic therapy to create a window of definitive diagnosis, one should consider close follow-up imaging to observe progression of the pseudoaneurysm. This may prevent the need of acute intervention.