How To Diagnose and Manage Infected Endografts after Endovascular Aneurysm Repair

Complications of thoracic endovascular aneurysm repair (TEVAR): A pictorial review

Thoracic endovascular aneurysm repair (TEVAR) has replaced open surgical repair as the treatment of choice for several aortic conditions. Despite its lower morbidity and mortality, several TEVAR-related complications can occur and some of which may necessitate surgical or endovascular re-intervention. The current article reviews common and rare complications of TEVAR procedure with emphasis on complications identifiable on cross-sectional imaging and potential pitfalls of pre-procedural planning.

Clinical outcomes of in situ graft reconstruction in treating infected abdominal aortic stent grafts following endovascular aortic aneurysm repair: a single-center experience

Purpose

This study aimed to review our experience with the explantation of infected endovascular aneurysm repair (EVAR) grafts.

Methods

This single-center, retrospective, observational study analyzed the data of 12 consecutive patients who underwent infected aortic stent graft explantation following EVAR between January 1, 2010 and December 31, 2019, of which 11 underwent in situ graft reconstruction following graft removal. The presentation symptoms, infection route, original pathology of abdominal aortic aneurysms (AAA), graft materials, and clinical outcomes were analyzed.

Results

Six patients underwent total explantation, whereas 5 underwent removal of only the fabric portions. For in situ reconstructions, prosthetic grafts and banked allografts were used in 8 and 3 patients, respectively. Four mechanisms of graft infection were noted in 11 patients: 4 had bacteremia from systemic infections, 3 had persistent infections following EVAR of primary infected AAA, 3 had ascending infections from adjacent abscesses, and 1 had an aneurysm sac erosion resulting in an aortoenteric fistula. No infection-related postoperative complications or reinfections occurred during the mean 65.27-month (standard deviation, ±52.51) follow-up period. One patient died postoperatively because of the rupture of the proximal aortic wall pseudoaneurysm that had occurred during forceful bare stent removal.

Conclusion

Regardless of graft material, in situ graft reconstruction is safe for interposition in treating an infected aortic stent graft following EVAR. In our experience, the residual bare stent is no longer a risk factor for reinfection. Therefore, it is important not to injure the proximal aortic wall when removing the bare stent by force.

Presentation and management of delayed aortic endograft infection

A man in his 60s who underwent endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm 4 years ago presents with 1 week of abdominal pain, fever and leucocytosis. CT angiogram demonstrated an enlarged aneurysm sac with intraluminal gas and periaortic stranding consistent with infected EVAR. He was clinically unfit for an open surgical intervention due to his significant cardiac comorbidities, including hypertension, dyslipidaemia, type 2 diabetes, recent coronary artery bypass grafting and congestive heart failure secondary to ischaemic cardiomyopathy with an ejection fraction of 30%. Therefore, due to this significant surgical risk, he was treated with percutaneous drainage for the aortic collection and lifelong antibiotics. The patient is well 8 months following presentation with no signs of ongoing endograft infection, residual aneurysm sac enlargement, endoleak or haemodynamic instability.

FDG PET/CT in abdominal aortic graft infection: A case report and literature review

This case report follows a 47-year-old man who had multiple grafts undergoing FDG PET/CT (positron emission tomography/computed tomography) scan to evaluate for graft infection. Initial CT showed enhancing soft tissue and fluid collection around the graft, and the subsequent FDG PET/CT showed findings concerning for graft infection. This case exemplifies that FDG PET/CT is a synergistic tool in diagnosing aortic graft infections, a rare and often fatal complication of aortic grafts.

The Technological Advancement to Engineer Next-Generation Stent-Grafts: Design, Material, and Fabrication Techniques

Endovascular treatment of aortic disorders has gained wide acceptance due to reduced physiological burden to the patient compared to open surgery, and ongoing stent-graft evolution has made aortic repair an option for patients with more complex anatomies. To date, commercial stent-grafts are typically developed from established production techniques with simple design structures and limited material ranges. Despite the numerous updated versions of stent-grafts by manufacturers, the reoccurrence of device-related complications raises questions about whether the current manfacturing methods are technically able to eliminate these problems. The technology trend to produce efficient medical devices, including stent-grafts and all similar implants, should eventually change direction to advanced manufacturing techniques. It is expected that through recent advancements, especially the emergence of 4D-printing and smart materials, unprecedented features can be defined for cardiovascular medical implants, like shape change and remote battery-free self-monitoring. 4D-printing technology promises adaptive functionality, a highly desirable feature enabling printed cardiovascular implants to physically transform with time to perform a programmed task. This review provides a thorough assessment of the established technologies for existing stent-grafts and provides technical commentaries on known failure modes. They then discuss the future of advanced technologies and the efforts needed to produce next-generation endovascular implants.

Listeria monocytogenes endograft infection after fenestrated endovascular aneurysm repair—a case report

An extremely uncommon cause of endograft infections, Listeria monocytogenes graft infections are associated with high morbidity and mortality. Best managed with complete graft resection and long-term antibiotic therapy, we present a rare case of L. monocytogenes aortic graft infection managed successfully with direct sac drainage and lifelong suppressive antibiotic therapy.

Periaortic air in native and post-operative aorta on computed tomography

Periaortic air can be seen in various conditions which can be a benign imaging finding or harbinger of a catastrophic event. The causes vary in native aorta and post-operative aorta. A radiologist has an important part in the management process of these patients, as the treatment varies from conservative to radical surgery based on the aetiology. The presence of periaortic air seen in the light of various clinical, laboratory and radiological findings can guide the radiologist towards a particular aetiology. Cross-sectional imaging, mainly computed tomography, is an indispensable tool in recognising ectopic periaortic air and to identify the associated findings and eventually make an accurate diagnosis. We present a pictorial review of various causes of the periaortic air in native and postoperative aorta, the salient features and management of the described conditions.

Stent-Graft Removal and Extra-Anatomical Bypass for the Treatment of Stent-Graft Infection after Endovascular Aneurysm Repair

Stent-graft infection is a rare but potentially life-threatening complication of endovascular aortic repair. There are currently no consensus guidelines for treating stent-graft infections, but surgical treatment is generally considered preferable due to the low overall survival rate of patients receiving conservative therapy; however, the revascularization method remains controversial. We report a case in which stent-graft infection after endovascular aneurysm repair was successfully treated by stent-graft removal and extra-anatomical bypass (EAB). EAB is an effective method of revascularization for stent-graft infection.

Spondylodiscitis After Endovascular Aortic Repair Due to Noninvasive Listeriosis: A Case Report

CASE

An 83-year-old man suffered progressive lower back pain 4 weeks after an endovascular aortic repair (EVAR) procedure. Computed tomography showed L4 vertebral body collapse and abnormal soft tissue-like density swelling with increased uptake on 18F-fluoro-D-glucose (FDG) positron emission tomography (PET)/CT. Listeria monocytogenes was identified from ultrasound-guided fine-needle aspiration. Ultrasound-guided drainage of the retroperitoneal abscess and intravenous antibiotic therapy with ampicillin and gentamicin resulted in the rapid relief of symptoms.

CONCLUSION

Spondylodiscitis after EVAR requires a timely diagnosis. Uncommon organisms such as L. monocytogenes must be suspected, even in focal infections without signs of listeriosis. Conservative treatment with preservation of the graft should be considered as long as close follow-up evaluations are performed.

Endoleak Complicated by communicating psoas abscess and aorto-enteric fistula in an immunocompromised patient

PURPOSE

While endovascular repair of aortic aneurysm (EVAR) has become the mainstay treatment for abdominal aortic aneurysm (AAA), it is not without its disadvantages. Feared complications include graft infections, fistulation and endoleak, the outcomes of which may be life limiting.

CASE REPORT

We present a case of a 57 year-old patient with human immunodeficiency virus (HIV) previously treated with EVAR for AAA complicated by endoleak post treatment. He developed an aorto-psoas abscess 2 years later which harboured Mycobacterium avium complex, and medical therapy was unsuccessful. He eventually underwent an extra-anatomical bypass and graft explant, for which an aortoenteric fistula was also discovered and repaired.

CONCLUSION

Infection of endografts post EVAR is relatively rare, and there are presently no guidelines concerning its management. The concomittance of aorto-psoas abscess and aortoenteric fistula is even more uncommon, and necessitated surgical explant for source control purposes in our patient. Lifelong surveillance is required for complications of the aortic stump and bypass patency.

Outpatient parenteral antimicrobial therapy (OPAT) for aortic vascular graft infection; a five-year retrospective evaluation

OBJECTIVES

An estimated 1% of endovascular aneurysm repair (EVAR) devices become infected, carrying a high mortality rate. Surgical explantation is recommended and prognosis is guarded. This retrospective cohort analysis focuses on the role of outpatient parenteral antimicrobial therapy (OPAT) in the management of aortic vascular graft infections following EVAR.

METHODS

Patients who received OPAT for aortic graft infections (AGI) following EVAR from 2014 to 2018 inclusive were identified using the OPAT database. Clinical, microbiological and radiological data were collected. Survivors were followed up for a median of 36 months (range 25-60) after first presentation with infection. Outcomes were assessed.

RESULTS

Eleven cases with 20 OPAT episodes were identified: 10/11 male, median age 76 (IQR 71-81). Median time to presentation was 7 months (range 0-81 months) after EVAR. OPAT lead to a 55% reduction in length of hospital stay. One patient had graft explantation; four others had temporising measures. Eight of 11 were alive a median of 36 months after presentation with infection, having had a median of 2 re-treatments on OPAT (range 1-3). Seven of the eight survivors were on continuous suppressive oral antimicrobials; three were also intermittently on intravenous antibiotics for flares of infection. Patient/ infection outcomes were cure (1/11), improved (7/11), failure (3/11).

CONCLUSION

AGI following EVAR usually presents in the first year after graft deployment. OPAT has an important peri-operative role in patients suitable for curative surgery. OPAT followed by oral suppressive antimicrobial therapy can be a feasible long-term treatment for non-curative management of AGI. Survival in our cohort was longer than expected, and OPAT was feasible despite the complexity of these infections. OPAT can avoid multiple and lengthy hospital admissions and maximise time at home and quality of life in this cohort with life-limiting infection.

Difficult diagnosis and management of a complicated Nellix graft infection

An 81-year-old man, with a complex vascular surgical history, presents with sepsis from an infected Nellix stent-graft. He required an urgent laparotomy, explantation of the graft, and extra-anatomical repair. Although now widely used for this indication, the preoperative 18F-fluorodeoxyglucose positron emission tomography/computed tomography was nondiagnostic for his stent-graft infection. We describe our management of a complicated Nellix graft infection and discuss the utility of positron emission tomography/computed tomography for stent-graft infections.

Candia albicans lumbar spondylodiscitis contiguous to infected abdominal aortic aneurysm in an intravenous drug user

While the incidence of spondylodiscitis is rising because of longer life expectancy and the increasing use of immunosuppressant drug, indwelling devices and spinal surgeries, the fungal aetiology remains rare, sometimes affecting intravenous drug users. Candida spondylodiscitis is an extremely rare complication post aortic aneurysm repair. It is potentially fatal due to the risk of aneurysm rupture and septic complications. The growing problem of systemic diseases caused by Candida species reflects the enormous increase of patients at risk. The treatment of this complicated entity is challenging and often requiring a multidisciplinary team. We reported the rare case of Candida spondylodiscitis contiguous to infected aortic aneurysm in a 74-year-old male intravenous drug user, to the extent which the vertebral body bony destruction progressed to need one-stage posterior and anterior spinal fusion surgery with curettage. Our surgical intervention combined with prolonged course of antifungal therapy could successfully eradicate the infection and resolve the neurological deficits.

Aortoduodenal fistulas after endovascular abdominal aortic aneurysm repair and open aortic repair

OBJECTIVE

In the present study, we have reported and compared aortoduodenal fistulas (ADFs) after endovascular abdominal aortic aneurysm repair (EVAR) vs after open aortic repair (OAR).

METHODS

We retrospectively analyzed the data from patients treated for ADFs from January 2015 to May 2020 in our hospital. The clinical data, diagnostic procedures, and surgical options were evaluated. The primary endpoints of the present study were 30-day and 1-year mortality. The secondary endpoints were major postoperative complications.

RESULTS

A total of 24 patients (20 men; median age, 69 years; range, 53-82 years) were admitted with ADFs after EVAR (n = 9) or OAR (n = 15). These patients accounted for ∼4.3% of all abdominal aortic aneurysm repairs in our hospital. The median interval from the initial aortic repair and the diagnosis of ADF was 68 months (range, 6-83 months) for the ADF-EVAR group and 80 months (range, 1-479 months) for the ADF-OAR group. Three patients in the ADF-EVAR group had refused surgical treatment owing to their high surgical risk. One patient in the ADF-OAR group had undergone removal of the aortic prosthesis without replacement. Of the remaining 20 patients, 12 (ADF-EVAR group, n = 4; ADF-OAR group, n = 8) had undergone in situ replacement of the aorta and 8 (ADF-EVAR group, n = 2; ADF-OAR group, n = 6) had undergone extra-anatomic reconstruction with aortic ligation. After a mean follow-up of 26 months, no patient had experienced early limb loss. However, one case of rupture of the venous graft (ADF-EVAR), one case of aortic stump blowout (ADF-OAR), and one case of a ureteroarterial fistula with a homograft (ADF-OAR) had occurred. Overall, the incidence of postoperative complications was significantly greater after ADF-OAR (93% vs 33%; P = .036). The most frequent bacteria involved in the blood cultures were Escherichia coli (25% of patients), and Candida spp. (61%) were the predominant pathogens found on intra-abdominal smears. The in-hospital mortality rates for the ADF-EVAR and ADF-OAR group were 22% and 13%, respectively. The corresponding 1 -year mortality rates were 22% and 33%.

CONCLUSIONS

Patients with ADFs after EVAR or OAR have limited overall survival. In addition to the similar therapeutic approaches, we found no significant differences in postoperative mortality between these two uncommon pathologic entities. In our study, the overall postoperative morbidity seemed greater for the ADF-OAR group.

Endovascular Graft Infection by Neisseria meningitidis: A Rare but Fatal Infection

Endovascular graft infection is a rare but challenging complication that requires a tailored approach to remove the infected graft and restore the arterial circulation combined with long-term antibiotic therapy. We present a case surgically treated with explant of the graft and reconstruction of the thoracoabdominal aorta. Microbiological investigation revealed growth of Neisseria meningitidis , which is extremely rare in this location, and to our knowledge, has not been previously published in the literature.

Aortobifemoral Bypass Grafting with Reversed L-Shaped Technique for Endograft Infection

Endograft infection after abdominal endovascular aortic repair is a rare but catastrophic complication associated with high perioperative mortality and postoperative recurrent infection. The optimal surgical treatment is still controversial, particularly regarding in situ or extra-anatomical revascularization. Herein, we describe a successful surgically treated case of a patient with an endograft infection complicated with abscess formation in the retroperitoneal space around the right common iliac artery. We performed an aortobifemoral bypass grafting using the reversed L-shaped technique by rerouting the right leg of the new prosthesis to avoid the infected area. The patient is doing well 1 year after surgery without recurrent infection. This technique was considered to be advantageous because revascularization could be performed remotely from the infected area.

Thoracic endovascular aortic repair in management of aorto-oesophageal fistulas: a case series

Background 

Aorto-oesophageal fistula (AOF) is a rare, catastrophic disease with an extremely poor prognosis. A ruptured thoracic aortic aneurysm is a common aetiology for AOF. The clinical presentation is usually massive haematemesis and collapse. Timely diagnosis and appropriate treatment are crucial in managing AOF.

Case summary 

We hereby report two cases of AOF, who underwent successful emergency thoracic endovascular aortic repair (TEVAR) to control active bleed and exsanguination. Case 1, an elderly lady with atherosclerotic aneurysm had TEVAR followed by open surgery for oesophageal rent and necrosed left main bronchus. Case 2 had mycotic tubercular aneurysm who later had infected graft-stent following TEVAR.

Discussion 

Open surgery is the conventional treatment for AOF; however, TEVAR can be an alternative and less invasive approach in selected high-risk patients. Various management issues related to TEVAR with AOF have been discussed in the article.

Hybrid Repair Combined with Fresh Arterial Allograft Extra-Anatomical Reconstruction: The Treatment of Infrarenal Abdominal Aneurysm above an Aortobifemoral Bypass Complicated by an Infected Pseudoaneurysm in the Left Groin

Introduction

A 72-year-old male patient was admitted into our centre with large infected pseudoaneurysm (PSA) in the left groin. The patient underwent a CT angiography (CTA) that confirmed a large partly thrombosed 6.5 × 5.5 cm PSA in the left groin arising from the distal anastomosis of the aortobifemoral bypass (ABF). Furthermore, the CTA revealed 11 cm juxtarenal abdominal aortic aneurysm (JAAA) from which the proximal anastomosis of the ABF was arising.

Method

Aorto-uni-iliac stent graft Cook was placed from the right groin trough native severely stenotic right iliac arteries with proximal landing zone below the renal arteries, excluding the JAAA and the ABF. The distal landing zone was in the common iliac artery maintaining patent right internal iliac artery. Afterwards, a femoro-femoral crossover bypass from right to left was performed using a fresh arterial allograft. Postprocedurally, the hospital stay was uneventful. The left groin PSA cultures came positive for Staphylococcus epidermidis and Corynebacterium tuberculostearicum, both sensitive to vancomycin and rifampicin.

Result

The patient underwent intravenous ATB treatment with vancomycin for two weeks, followed by four weeks of oral rifampicin. The patient was discharged on the 20^th postoperative days.

Conclusion

Hybrid repair combining aortic stent graft and extra-anatomical bypass in the treatment of infected distal parts of an aortofemoral bypass is an acceptable treatment modality.

Aortic Prosthesis-Associated MDR Pseudomonas Infections as a Diagnostic and Therapeutic Challenge

Endovascular prostheses are used to treat life-threatening conditions such as ruptured aortic aneurysms. Prosthetic infection cause significant morbidity and mortality, posing important diagnostic and therapeutic challenges. It is particularly difficult to diagnose and, in the era of multidrug resistance (MDR), these type of infections may become even more difficult to treat. Herein, we reported a case of a secondary prosthetic endovascular infection following repeated bacteremia episodes from a urinary source. This case illustrates an MDR Pseudomonas aeruginosa aortic infection that was difficult to diagnose with no oral antibiotic treatment options.

Thoracic endovascular aortic repair for aortobronchial fistula: a case series

Background

Aortobronchial fistula (ABF) formation following the rupture of thoracic pseudoaneurysm is a rare clinical entity. Its aetiology includes atherosclerosis, infections, trauma, post-surgery, and post-endovascular aortic repair. The clinical presentation of ABF includes intermittent or massive haemoptysis, acute respiratory distress, hypotension, and even death. These patients require an emergency aortic intervention to stop active haemorrhage. Thoracic endovascular aortic repair (TEVAR) is a less invasive, safe, and effective treatment compared to conventional open surgical repair

Case summary

We hereby report three cases of ruptured descending thoracic aortic pseudoaneurysms resulting in a fistula formation. The first two cases had tuberculosis as their underlying aetiology, while the third case was the result of previous open post-aortic surgery. All patients presented with massive haemoptysis and were successfully treated by emergency TEVAR and had favourable outcomes.

Discussion

Thoracic endovascular aortic repair is a rapid, less invasive, and effective treatment for emergency management of ABF. It has more than 85% technical success rates in the reported literature. We had procedural success in all three cases. The short and midterm outcome of ABF following TEVAR is favourable and encouraging.

A rare case of an infected aortoiliac graft complicated with Eggerthella lenta bacteremia and septic shock

We describe the successful medical management of an infected aorto-bi-Iliac endograft. In this case report, we provide an example of a patient with an infected aorto-bi-iliac endograft and how appropriate medical management may result in a positive outcome. We report a case of a 67-year-old man with several medical comorbidities who developed aorto-bi-iliac endograft infection one year after graft placement. The patient presented to our E.R. with fever, lethargy, tachycardia, tachypnea, and hypotension. The diagnosis of an infected endograft was established after excluding any other possible source of infection plus the strong radiological evidence by computed tomographic scan and WBCs labeled Indium-111 tropolone scan. Blood cultures revealed the development of Eggerthella lenta, Escherichia coli Extended-spectrum beta-lactamase (ESBL), and Enterococcus Faecalis. To our knowledge, this is a rare case of an infected endograft and bacteremia due to Eggerthella lenta. After the administration of vancomycin and Meropenem, no improvements were noted to the patient’s clinical condition. However, upon the administration of Tigecycline, the patient’s clinical condition improved. Two days later, repeat blood cultures were negative.

After completion of the course of antibiotics and stabilization of other comorbidities, the patient was discharged home with long term antibiotic therapy under close control of inflammation markers.

Management of Vascular Infections in Low- and Middle-Income Countries

Background: Vascular infections are rare and challenging conditions with significant deaths and morbidity. Their management necessitates a multi-disciplinary approach and substantial human and financial resources. The management selected may be influenced by the available resources in low- and middle-income countries (LMICs), where such resources may be variable. Methods: We reviewed the published literature and reviewed the management options for various vascular infections with a focus on carotid, aortic, infrainguinal, and dialysis access infections. Results: Recommendations related to prevention and treatment will be offered from the perspective of LMICs. The general principles for prevention are in compliance with established surgical site infection guidelines and minimize the use of prosthetic material. Early detection and intervention by removing all infected prosthetic material, debridement, drainage, and coverage of the infected field with vascularized tissue are essential steps in the management of the infection. Revascularization using an extra-anatomic or in situ approach is individualized based on the resources and expertise available. Conclusions: The prevention and management of vascular infections in LMICs are effective by adhering to time-proven principles even with limited resources.

Stent Graft Expulsion Outside the Skin: A Rare Case

Patients who undergo stent grafting may present to the ED some time after the procedure with various related symptoms. The most common of these are stent graft occlusions or hematoma, although infection or abscess also may develop. In this case report, a 58-year-old man presented to the ED with a purulent wound on the stump of an amputated leg and a foreign body protruding from the wound site. The patient had a history of stent insertion with femoropopliteal bypass 11 years before this incident and an above-the-knee amputation because of stent occlusion 8 years prior. This wound had appeared with reddening of the skin 1 month before presentation, followed by the emergence and protrusion of a foreign body.

Emergence of a lymphoma imitating an infectious infiltration surrounding the infrarenal aorta after EVAR

Primary retroperitoneal localization of non-Hodgkin's lymphoma is rare but should be considered, even if the circumstances surrounding its emergence point to other direction. We present a case of an appearance of periaortic infiltration after successful endovascular treatment which turned out to be of malignant origin.

How to recognize stent graft infection after endovascular aortic repair: the utility of 18F-FDG PET/CT in an infrequent but serious clinical setting

OBJECTIVE

To evaluate the diagnostic performance of ¹⁸F-FDG PET/CT in the detection of stent graft infection (SGI).

METHODS

In a retrospective study, two nuclear medicine physicians have independently analyzed 17 ¹⁸F-FDG PET/CT examinations performed for clinical suspicion of SGI. The images were evaluated for the uptake pattern and intensity, and by the maximum standard uptake value (SUV_max), the target-to-background ratio with blood pool (TBR_BP) and liver uptake (TBR_hep) as a reference. The SGI was defined as the presence of focal hyperactivity with an intensity exceeding hepatic uptake. CT images were independently assessed for signs of SGI. Clinical review of all further patients' data served as the standard of reference.

RESULTS

Nine cases were established as SGI by the clinical review. PET/CT correctly diagnosed SGI in eight and yielded a sensitivity of 89% and specificity of 100%. The mean SUV_max, TBR_BP, and TBR_hep values were 9.8 ± 4.0, 6.9 ± 2.6, and 4.6 ± 1.7 in the group of patients with true SGI, and 4.0 ± 1.1, 2.5 ± 0.4 (p < 0.001) and 1.9 ± 0.2 (p < 0.001) in true negative cases, respectively. CT alone showed a sensitivity of 78% and specificity of 100% and was concordant with PET/CT in 14 cases. The best performing threshold values of SUV_max, TBR_BP, and TBR_hep were 5.6, 3.5, and 2.2, respectively.

CONCLUSION

¹⁸F-FDG PET/CT with expert evaluation, semiquantitative and quantitative image analysis with the proposed threshold values for SUV_max, TBR_BP, and TBR_hep has good diagnostic accuracy in the detection of SGI. We propose that visual grading scale for SGI should use hepatic uptake as a visual reference.

Infection-relapse and a potentially surgical stratification model for the treatment of mycotic aortic aneurysms: A propensity-matched pilot study

Objective

This study evaluates the overall survival and the infection-relapse after endovascular repair (Endo) vs. open surgery (Open) for mycotic aortic aneurysms and the potential influence of perioperative severity of infection to the decision-making on the long-term survival.

Design

A multicenter, retrospective analysis of 5247 consecutive aortic aneurysm repair performed from January 2003 to December 2017 at five tertiary medical centers was conducted. Among the study population, 257 patients with mycotic aortic aneurysms s were identified. Methods: Finally, 73 patients were enrolled in the cohort after exclusion and a 1:1 propensity-matched analysis. The study cohort drawn from matched data included 37 patients in the Endo group and 36 patients in the Open group. The primary endpoint was overall survival. Secondary endpoints included infection-relapse during the follow-up. Univariate and multivariate Cox regression analyses were used to assess predictors for late mortality.

Results

The mean follow-up time for the entire cohort was 41 months (range, 1 to 135 months). Among propensity-matched patients, there was no significant difference in baseline characteristics. There was no difference in overall survival ( P = 0.083) between the groups at five years, but Open group was associated with a lower infection-relapse incidence during the follow-up ( P = 0.011). Subgroup analysis revealed a better survival rate for Open in patients with severe infection ( P = 0.003) or small periaortic abscess ( P = 0.049).

Conclusion

There were no significant differences between Endo and Open in overall survival. However, Open was a more definite option with less infection-relapse and had potential advantages for patients with severe infection or with a small periaortic abscess.

Open surgery and endovascular repair for mycotic aortic aneurysms: Benefits beyond survival

OBJECTIVE

Endovascular techniques have been increasingly used to treat mycotic aortic aneurysms. However, apart from survival, the potential benefits of open surgery and endovascular repair for mycotic aortic aneurysms are poorly understood. The aim of this study was to evaluate the short- and mid-term outcomes after open surgery versus endovascular repair for mycotic aortic aneurysms.

METHODS

All patients treated for mycotic aortic aneurysms at Peking University People's Hospital between 2001 and 2017 were identified. Survival was analyzed using Kaplan-Meier analysis and log-rank tests. The reoperation rate was analyzed using a competing-risk analysis.

RESULTS

Forty-three patients were identified. The mean follow-up time was 41 months (median, 29; range, 1-135 months). The 30-day mortality in the open surgery group was 8.7% (2/23) versus 5% (1/20) in the endovascular repair group (P = .999). The overall survival for open surgery and endovascular repair was 78% versus 75%, respectively, at 1 year, and 69% versus 41% (P = .210), respectively, at 5 years. But during the follow-up, the open surgery group demonstrated multiple benefits, including a shorter length of hospital stay (26.80 ± 14.1 days vs 42.73 ± 21.22 days, P = .026), fewer readmissions (mean 0.61 vs 1.30, P = .037), and lower infection-related reoperations (P = .018) than endovascular repair at 3 years. Subgroup analysis revealed better survival for open surgery in patients with a periaortic mass less than 20 mm (P = .03).

CONCLUSIONS

There were no significant differences between endovascular repair and open surgery in survival. However, in the mid-term, the potential benefits of open surgery are favorable compared with endovascular repair, including lower infection-related reoperation rates and reduced medical burden.

Infrarenal Aortic Endograft Infection: A Single-Center Experience

PURPOSE:

Endograft infection is an infrequent but one of the most serious and challenging complications after endovascular aortic repair. The aim of this study was to assess the management of this complication in a tertiary center.

CASE SERIES:

A retrospective analysis of a prospective database was performed including all patients who underwent elective endovascular abdominal aortic repair (EVAR) from 2003 to 2016 in a tertiary center. Seven cases of endograft infection were identified during the follow-up period from a total of 473 (1.48%) EVAR. Most frequent symptoms at presentation were fever (71.4%) and lumbar pain (57.1%). One case developed an early infection, while 6 cases were diagnosed as late infections. Mean time from endograft placement to symptom presentation was 28.3 months (2-91.5 months). Gram-positive cocci were the microorganisms most commonly isolated in blood cultures (66%). Two cases were managed with endograft removal and aortic reconstruction with a cryopreserved allograft, 2 cases with surgical drainage, and 2 cases exclusively with antibiotic therapy. In 1 case, the diagnosis was performed postoperatively based on intraoperative findings associated with positive graft cultures; and graft explantation was performed with "in situ" reconstruction using a Dacron graft. Perioperative mortality was 42.9%. One-year mortality was 57.1%. Mean follow-up was 21.5 months.

CONCLUSION:

Endograft explantation is the gold standard of treatment; however, given the overall high morbi-mortality rates of this pathology, a tailored approach should always be offered depending on the patient's overall condition. Conservative management can be an acceptable option in those patients with short life expectancy and high surgical risk.

Infected abdominal aortic aneurysm graft complicated by lumbar discitis

We present the case of a 68-year-old male, who underwent open abdominal aortic graft in August 2016 owing to a ruptured large infrarenal abdominal aneurysm. He subsequently presented 6 months later with back pain, general weakness, reduced mobility and cachexia. He underwent CT, MRI and fluorodeoxyglucose (PDG)-PET spinal imaging, all modalities showing signs of aortic graft infection complicated by L4/5 discitis. The patient was treated conservatively with intravenous antibiotics and spinal brace support, as his general condition did not allow for surgery. Although he showed initial clinical improvement allowing plans for supported discharge, his improvement was not sustained and he died 4 months after admission.

Determining the Diagnostic Value of 18F-Fluorodeoxyglucose Positron Emission/Computed Tomography in Detecting Prosthetic Aortic Graft Infection

BACKGROUND

To determine the diagnostic value of 18F-fluorodeoxyglucose positron emission/computed tomography (FDG PET/CT) in detecting prosthetic aortic graft infection (AGI).

METHODS

Twenty-one patients with prosthetic grafts for abdominal aortic aneurysms underwent FDG PET/CT scans for suspected graft infection over a 15-month period. Images were evaluated for tracer pattern and grade of FDG uptake in addition to measuring the maximal standardized uptake value (SUVmax). Two independent nuclear medicine physicians retrospectively evaluated all imaging. The images from a control group of patients with aortic grafts who underwent FDG PET/CT scans for onco-hematological indications were evaluated to establish radiological characteristics of asymptomatic grafts. Secondary parameters that are associated with graft infection such as components of the peripheral blood count were collected. Graft infection status was determined using microbiological outcomes following graft explantation or radiological drainage of perigraft collections and correlated with results of the FDG PET/CT scans to determine infective status.

RESULTS

In the control group, the pattern of FDG uptake was homogenous and diffuse. The mean SUVmax was 3.5 (±1.3). Thirteen out of 21 grafts were confirmed as infected. Tracer uptake in infected grafts displayed an intense and focal pattern, with a median grade of uptake of 4 vs. 2 on a validated 4 point grading scale. The area under the receiver operating curve for FDG PET/CT in detecting infection was 0.85 (±0.15) P = 0.01. Sensitivity was 92%, specificity 63%, and positive and negative predictive values of 80% and 83%, respectively. The SUVmax was significantly higher in infected than noninfected grafts, (10.3 ± 4.2 vs. 5.4 ± 3.4) P = 0.02. According to the receiver operating characteristic analysis, SUVmax greater than 6.3 represented the optimal cutoff between infective and noninfective outcome. Of the secondary parameters collected, grade of uptake and SUVmax were the only significant predictors of infection (odds ratio 2.5, 1.5 respectively) P = 0.05. White cell count, erythrocyte sedimentation rate, and C-reactive protein demonstrated nonsignificant odds ratios of 1.4, 0.9, and 1.0, respectively.

CONCLUSIONS

FDG PET/CT is a valuable diagnostic test for identifying AGI. Infected grafts display significantly greater FDG uptake in a distinctive intense focal perigraft pattern and distribution. SUVmax greater than 6.3 is a good cutoff to determine infective status.

Current Evidence on Management of Aortic Stent-graft Infection: A Systematic Review and Meta-Analysis

BACKGROUND

Aortic stent-graft infection (SGI) is rare but remains one of the most challenging and threatening complications. This systematic review aimed to identify the clinical features, treatment, and outcomes of endograft infection after abdominal endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR).

METHODS

A systematic literature review of all published literature from January 1991 to September 2016 on SGI was performed under the instruction of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Aorta, aneurysm, endovascular, stent-graft, endograft and infection were the keywords used in our comprehensive search in PubMed and MEDLINE databases. Data analysis was performed using SPSS, V 22.0.

RESULTS

A total of 185 potential relevant articles were identified, but only 11 studies with 402 patients met the inclusion criteria. Majority of the patients were male (308/402, 77%), with a mean age ranging from 65 to 73 years. Most of the endografts were implanted for EVAR (351/402, 87%), while the other 51 (13%) endografts were infected following TEVAR. Among the 402 patients, 39 (9.7%) patients presented with aortic rupture. Ninety-two of 380 (24.2%) patients with available data had aortoenteric fistula (AEF). Sixty-nine patients (17%) died in hospital or within 30 days after operation. One hundred fourteen patients (28%) died during follow-up. The most commonly used stent grafts were Zenith (Cook Inc, Bloomington, IN) (22%) and Excluder (W.L. Gore, Flagstaff, AZ) (20%). Of the 402 patients in this series, 108 patients (27%) had negative culture, and multiple microorganisms were identified in 103 patients (26%). The most frequently isolated microorganisms were Staphylcoccus species (30.1%), Streptococcus (14.8%), and fungus (9.2%). Forty-two patients (42/401, 10%) received conservative treatment, whereas 359 (90%) patients underwent surgical treatment, including stent graft removal with in situ reconstruction or extra-anatomical bypass, and secondary endovascular procedure. Patients in the surgical group had a higher survival rate compared with conservative group (58% vs. 33%, P = 0.002). The survival rate was higher in the patients with infected EVAR than TEVAR (58% vs. 27%, P = 0.000). Patient with AEF had a worse prognosis (survival rate 72% vs. 33%, P = 0.002).

CONCLUSIONS

Current evidence suggests that surgical treatment is a better option compared with conservative management in selected patients with aortic endograft infection. The outcome was worse in patients with infected TEVAR and AEF.

Explantation of an Infected Fenestrated Abdominal Endograft with Autologous Venous Reconstruction

INTRODUCTION

Infectious complications after FEVAR cause significant problems, with radical surgery considered to be the last resort for treatment.

CASE REPORT

A 72 year old man presented with infection 1 month after FEVAR. Conservative therapy with percutaneous abscess drainage and antibiotics suppressed the infection for 10 months; however, when new peri-aortic abscesses developed, the patient agreed to revision surgery. The endograft was explanted and an autologous in situ venous reconstruction was performed. As a result of post-operative complications, the patient died 3 days later.

CONCLUSION

This study demonstrates that autologous venous reconstruction is technically feasible. An earlier decision on such radical surgery could potentially have improved the patient's chances of survival.

Spondylitis transmitted from infected aortic grafts: a review

Graft infection following aortic aneurysms repair is an uncommon but devastating complication; its incidence ranges from <1% to 6% (mean 4%), with an associated perioperative and overall mortality of 12% and 17.5-20%, respectively. The most common causative organisms are Staphylococcus aureus and Escherichia coli; causative bacteria typically arise from the skin or gastrointestinal tract. The pathogenetic mechanisms of aortic graft infections are mainly breaks in sterile technique during its implantation, superinfection during bacteremia from a variety of sources, severe intraperitoneal or retroperitoneal inflammation, inoculation of bacteria during postoperative percutaneous interventions to manage various types of endoleaks, and external injury of the vascular graft. Mechanical forces in direct relation to the device were implicated in fistula formation in 35% of cases of graft infection. Partial rupture and graft migration leading to gradual erosion of the bowel wall and aortoenteric fistulas have been reported in 30.8% of cases.

Rarely, infection via continuous tissues may affect the spine, resulting in spondylitis. Even though graft explantation and surgical debridement is usually the preferred course of action, comorbidities and increased perioperative risk may preclude patients from surgery and endorse a conservative approach as the treatment of choice. In contrast, conservative treatment is the treatment of choice for spondylitis; surgery may be indicated in approximately 8.5% of patients with neural compression or excessive spinal infection. To enhance the literature, we searched the related literature for published studies on continuous spondylitis from infected endovascular grafts aiming to summarize the pathogenesis and diagnosis, and to discuss the treatment and outcome of the patients with these rare and complex infections.

Late Stent Graft Infection after the Emergency Endovascular Repair of a Secondary Iliac Artery-Enteric Fistula Treated with Graft Removal and In Situ Aortic Reconstruction Using Femoral Veins

An arterioenteric fistula is a devastating and life-threatening condition that requires urgent treatment. Less-invasive endovascular treatment has emerged as an alternative to conventional open repair, but postoperative graft infection remains a major concern. We herein report a case of late stent graft infection after emergency endovascular repair of a secondary iliac artery-enteric fistula. The patient was a 63-year-old male who presented with a fever, who had undergone successful endovascular stent grafting for a secondary common iliac artery-enteric fistula 29 months prior. The diagnosis of a stent graft infection was confirmed via computed tomography. He underwent graft removal and in situ reconstruction with femoral vein grafts. At 6-month follow-up, the patient is in a good general condition without any symptoms.