Endograft Infection Research Articles

A Case of Infected Endograft Explanation Following Thoracic Endovascular Aortic Repair for Distal Anastomotic Infectious Pseudoaneurysm after Total Arch Replacement

A Case of Infected Endograft Explanation Following Thoracic Endovascular Aortic Repair for Distal Anastomotic Infectious Pseudoaneurysm after Total Arch Replacement

768. ENDOSCOPIC MANAGEMENT OF COMPLEX THORACIC AORTA ANEURYSMAL SAC AND ENDOGRAFT INFECTION ASSOCIATED WITH AORTOESOPHAGEAL FISTULA

Abstract Background Aortoesophageal fistula (AEF) is a rare but life-threatening condition. Secondary AEF is a complex pathology occurring after thoracic aorta surgery with prosthetic graft, with an incidence of 1.6%. However, this is likely to rise with the increasing number of thoracic endovascular aortic repair (TEVAR) being performed. Management of secondary AEF is more challenging due to presence of adhesions in the pleural space, co-existing endograft infection and poor physiology of this group of patients. Definitive surgery carries high mortality rate and not all patients are suitable candidates. We review a case of secondary AEF with thoracic endograft infection managed non-operatively. Methods Our patient is a 70 years old man with a background of Stanford type A aortic dissection managed with ascending aorta and hemi-arch replacement with Dacron graft. Six years later, he had frozen elephant trunk reconstruction due to aneurysmal dilatation. Three months later, he underwent TEVAR for descending thoracic aorta aneurysm. Post-operation, he was diagnosed with Flavonifractor plautii bactaeremia secondary to infected aneurysmal sac and aortic stent graft and was initiated on antimicrobial therapy. During this time patient also developed recurrent episodes of haemoptysis. Bronchoscopy excluded an aortobronchial fistula and Oesophago-gastro-duodenoscopy (OGD) confirmed AEF at 25 cm from incisors. Results After discussion with a multidisciplinary team and patient, endoscopic management was chosen over surgery. Initial endoscopic closure of AEF with over-the-scope-clip appeared satisfactory but repeat OGD showed recurrence of new AEF which was partially closed with clips. Repeat imaging showed worsening mediastinal infection with larger gas-containing cavity. OGD was repeated with contrast demonstrating fistulous connection between the oesophagus and aneurysmal sac. A 7-French 4 cm double pigtail (DPT) stent was deployed into the sac under fluoroscopy to allow for trans-oesophageal drainage. Repeat imaging showed improvement in infection (Figure 1). Patient underwent endoscopic exchange of DPT stent 2 months after the initial insertion. Conclusion Definitive surgery for secondary AEF includes drainage of infection, explantation of infected endograft and aortic and oesophageal reconstruction. Oesophagectomy is preferred over primary repair of oesophageal defect. Not all patients will be suitable candidates for radical surgery and a non-operative approach may be required. Our patient likely has dense pleural and mediastinal adhesions from previous surgeries and thus, repeat surgery will be more challenging with increased risk of complications. However, if his mediastinal infection fails to resolve despite a period of DPT stent drainage, definitive surgery involving McKeown minimally invasive oesophagectomy with substernal gastric pull up would be required. Figure 1: Image A shows a large cavity with air and coalescent locules (arrow) prior to insertion of DPT stent. Image B shows a collapsed cavity (arrow) after DPT stent insertion.

Urgent or Emergent Endovascular Aortic Repair of Infective Aortitis.

Background: Aortitis is a rare inflammation of the aorta. It can be classified as infective, non-infective, or idiopathic. Infective aortitis can debut as an acute aortic syndrome that needs urgent or emergent treatment. Historically, these kinds of patients have been preferably treated by open surgery, with subsequent lack of information about the endovascular repair. The aim of the present study is to report the results of our experience with the urgent or emergent endovascular repair of infective aortitis with acute presentation. Methods: All consecutive urgent or emergent endovascular repairs, performed between January 2019 and January 2024 for the treatment of infective aortitis, were included. The inclusion criteria were clinical, laboratory, and radiological findings recognized as aortitis risk factors. Patients with graft or endograft infection, aortic fistulae, and mycotic aneurysm were excluded. Primary endpoints were technical success and 30-day and follow-up survival. Early and late major adverse events, any changes in lesion morphology over time, and need for re-intervention were also assessed. Results: A total of 15 patients (14 males and 1 female) with a mean age of 74.2 ± 8.3 were included. All the subjects were treated by endovascular means in an urgent or emergent setting because of a rapidly growing aneurysm, symptomatic lesion, or contained or free aortic rupture. The diagnosis of infective aortitis was confirmed postoperatively by positive blood cultures in all the patients. A rapidly growing or symptomatic lesion was noted in all 15 subjects. Among these there were six (40%) contained and two (13%) free aneurysm ruptures. The endovascular techniques performed were as follows: four thoracic-EVAR (TEVAR), three off-the-shelf branched-EVAR (BEVAR), one Chimney-EVAR (Ch-EVAR), six EVAR with bifurcated graft, and one EVAR with straight tube graft. Technical success was achieved in 100% of the patients. Two patients (13%) died within 30 days after the index procedure. No case of early aortic-related mortality was registered. During a mean follow-up of 31.6 ± 23.1 months (range 1-71), no further death or major adverse event was registered among the remaining 13 alive patients. Re-interventions were performed in three cases (20%). Aneurysm's shrinkage > 5 mm or stability was noted in 10 of the 13 patients who survived the early period after repair. Conclusions: Despite the relative reluctance to use an endograft in an infected area, in our experience the endovascular approach resulted to be feasible, safe, and effective in the treatment of infective aortitis with acute presentation, with acceptable peri-operative and mid-term follow-up outcomes. Further studies are needed to confirm our results.

Serial dilation to enable ulnar artery access for endovascular neurointervention: Technical report and systematic review of the literature

BackgroundFor rare neuro-endovascular cases in which transfemoral access is not feasible and the palmar circulation is insufficient for radial artery access, ulnar artery access may be considered. Materials and methodsMechanical thrombectomy via ulnar artery access was performed to preserve the dominant radial artery. The ulnar artery was serial dilated to 7-French with microdilator. Angiography was performed using a diagnostic catheter. The sheath was exchanged for a guide catheter, and a triaxial system was inserted. A mechanical thrombectomy was performed. The systematic literature review included all studies pertaining to techniques for ulnar artery access for neurointervention in the last 20 years (2003–2023) published in the PubMed, Web of Science, and Embase databases. Results67-year-old male developed left MCA syndrome in the setting of an infected abdominal aortic endograft. A transfemoral approach was ruled out due to concern for crossing the infected endograft. Allen test and ultrasound demonstrated that the right radial artery was of adequate size for access, but the ulnar artery was insufficient to support the palmar arch. Mechanical thrombectomy resulted in TICI 3 reperfusion. Systematic review of the literature yielded 2 case series and 1 case report of transulnar neurovascular procedures. Access site complications were rare and included 3 access site hematomas and 1 ulnar artery occlusion. ConclusionWe report our technique of serial dilation of the ulnar artery for neuroendovascular procedures and provide a systematic review of the literature for complication avoidance in ulnar artery access.

Aortic Endograft Infections: A Race against Time

Aortic Endograft Infections: A Race against Time

An ex vivo study of infections of vascular grafts and endografts with scanning electron microscopy

ObjectiveVascular graft and endograft infections (VGEIs) are complicated by high morbidity, mortality, and recurrence rates, notably due to biofilm formation on the graft surface, hardly dislodgeable by the sole anti-infectious treatment. The characteristics of this biofilm are still poorly documented. The aim of this study was to evaluate ex vivo biofilm on removed infected vascular grafts and endografts (VGEs). MethodsExplanted VGEs were prospectively collected from 2019 to 2022 at Bordeaux University Hospital, France. Two samples per graft were used for scanning electron microscopy imaging; one was sonicated, and both grafts’ sides were imaged. ResultsA total of 26 patients were included, 18 with VGEI, eight without any infection (endoleak and/or thrombosis), and 29 VGEs were collected. Microbial documentation was obtained in 83% of VGEIs. A thick layer of fibrin was visible on almost all grafts, mixed with a dense biofilm matrix on infected grafts visible as early as 1 month after the onset of infection. Bacteria were not always visualized on infected grafts’ surface (80% on outer side and 85% on luminal side) but were surprisingly present on one-third of non-infected grafts. There was no significant difference between biofilm, fibrin, and microorganisms’ distribution between the two grafts’ sides. However, there were clear differences between infected and non-infected grafts, since immune cells, bacteria and biofilm were more frequently visualized on both sides of infected grafts (P < .05). Bacteria and immune cells although still visible, were significantly less present after sonication; the number of other elements including biofilm was not significantly different. ConclusionsThe persistence of a thick layer of fibrin and biofilm embedding microorganisms on both sides of infected VGE even after 1 month of infection could be the explanation for the low success rates of conservative management and the usual need for graft removal to treat VGEIs.

Coaxial electrospun Ag-NPs-loaded endograft membrane with long-term antibacterial function treating mycotic aortic aneurysm

The use of endovascular stent-graft has become an important option in the treatment of aortic pathologies. However, the currently used endograft membranes have limited ability to prevent bacterial colonization. This makes them unsuitable for the treatment of mycotic aneurysms, as the infection is prone to progress after endograft implantation. Moreover, even in non-mycotic aortic pathologies, endograft infections can occur in the short or long term, especially for patients with diabetes mellitus or in immune insufficiency conditions. So, this study aimed to develop a kind of Ag-NPs-loaded endograft membrane by coaxial electrospinning technique, and a series of physical and chemical properties and biological properties of the Ag-NPs-loaded membrane were characterized. Animal experiments conducted in pigs confirmed that the Ag-NPs-loaded membrane was basically non-toxic, exhibited good biocompatibility, and effectively prevented bacterial growth in a mycotic aortic aneurysm model. In conclusion, the Ag-NPs-loaded membrane exhibited good biocompatibility, good anti-infection function and slow-release of Ag-NPs for long-term bacteriostasis. Thus, the Ag-NPs-loaded membrane might hold potential for preventing infection progression and treating mycotic aortic aneurysms in an endovascular way.

Aortic endograft infection by Mycobacterium abscessus subsp. massiliense with acquired clarithromycin resistance: a case report

BackgroundMycobacterium abscessus subsp. massiliense (MMA) comprises a group of non-tuberculous, rapidly growing mycobacteria. Although MMA can cause pulmonary diseases, surgical site infections, and disseminated diseases, aortic endograft infection has not been reported. Here, we describe the first case of aortic endograft infection caused by MMA.Case presentationTwo months after stent-graft insertion for an abdominal aortic aneurysm, an 85-year-old man was admitted with fever and abdominal pain and was diagnosed with aortic endograft infection. Despite 14 days of meropenem and vancomycin intravenous administration, periaortic fluid pooling increased as compared to that before antibiotic administration. The abscess was drained, and fluorescent acid-fast staining of the abscess fluid revealed bacilli. We conducted genetic tests on the genes hsp65, rpoB, and sodA, performed Whole Genome Sequencing (WGS), and identified the organism as MMA. Intravenous imipenem–cilastatin (IPM/CS), amikacin (AMK), and oral clarithromycin (CAM) were administered. After 2 months, oral CAM and sitafloxacin were administered because the abscess had decreased in size. However, after 6 weeks, the abscess increased in size again. Antimicrobial susceptibility testing of the drainage fluid from the abscess resulted in the isolation of an MMA strain that had acquired resistance to CAM. Intravenous IPM/CS, AMK, and oral linezolid were added to the treatment regimen along with oral CAM and STFX. However, he was not fully cured and died 6 months later. Neither the full-length erythromycin ribosome methyltransferase (erm)(41) gene nor the rrl or rpIV gene mutations were found by Sanger sequencing in the pre- and post-treatment strains. Whole-genome sequence analysis of the post-treatment strain revealed mutations in genes with no previous reports of association with macrolide resistance.ConclusionsAortic endograft infection caused by MMA strain is extremely rare; nonetheless, MMA should be suspected as the causative microorganism when broad-spectrum antimicrobials are ineffective.

Twenty-Five Year Multicentre Experience of Explantation of Infected Abdominal Aortic Endografts.

We report a multicenter experience of open conversions (OC) for aortic endograft infections (AEI). We retrospectively analyzed all patients who underwent OC for AEI after endovascular aneurysm repair (EVAR), from 1997 to 2021 in 12 Italian centers. The endpoints were as follows: mortality (30-days, in-hospital), major postoperative complications. Follow-up data included: survival, aortic-related complications, infection persistence or reoccurrence. Fifty-eight patients (mean age: 73.8 ± 6.6years) were included. Median time from EVAR to OC was 14months (interquartile range 7-45). Thirty-five patients (60.3%) were symptomatic at presentation. Aortic reconstruction was anatomic in 32 patients (55.2%), extra-anatomic in 26 (44.8%). Thirty-day mortality was 31% (18/58). Six additional patients died after 30days during the same hospitalization (in-hospital mortality: 41.4%). Most common post-operative complications included respiratory failure (38.6%) and renal insufficiency (35.1%). During 28.1 ± 4months follow-up, 4 aneurysm-related deaths were recorded. Infection re-occurred in 29.4% of the patients. Estimated survival was 50% at 1year, and 30% at 5years, and was significantly lower for patients who underwent extra-anatomic reconstructions (37 vs 61% at 1year, 16 vs 45% at 5years; log-rank P = .021). OC for AEI is associated with high early mortality. The poor mid-term survival is influenced by aortic complications and infection re-occurrence.

Aortic Endograft Infection: Diagnosis and Management.

Aortic endograft infection (AEI) is a rare but life-threatening complication of endovascular aneurysm repair (EVAR). The clinical features of AEI range from generalized weakness and mild fever to fatal aortic rupture or sepsis. The diagnosis of AEI usually depends on clinical manifestations, laboratory tests, and imaging studies. Management of Aortic Graft Infection Collaboration (MAGIC) criteria are often used to diagnose AEI. Surgical removal of the infected endograft, restoration of aortic blood flow, and antimicrobial therapy are the main components of AEI treatment. After removing an infected endograft, in situ aortic reconstruction is often performed instead of an extra-anatomic bypass. Various biological and prosthetic aortic grafts have been used in aortic reconstruction to avoid reinfection, rupture, or occlusion. Each type of graft has its own merits and disadvantages. In patients with an unacceptably high surgical risk and no evidence of an aortic fistula, conservative treatment can be an alternative. Treatment results are determined by bacterial virulence, patient status, including the presence of an aortic fistula, and hospital factors. Considering the severity of this condition, the best strategy is prevention. When encountering a patient with AEI, current practice emphasizes a multidisciplinary team approach to achieve an optimal outcome.

Early and Midterm Outcomes of Endovascular Aneurysm Repair With Zenith Alpha Abdominal Stent-Graft: Results From a Multicenter Retrospective Tuscany Registry.

Zenith Alpha Abdominal (Cook Medical, Bloomington, IN, USA) is one of the new-generation low-profile stent-grafts with demonstrated satisfactory early and midterm clinical outcomes for endovascular treatment of abdominal aortic aneurysms (AAAs). The aim was to evaluate early and midterm results of this device in the framework of a multicenter regional retrospective registry, with the analysis of morphological factors affecting outcomes, including different limb configurations. Between January 2016 and November 2021, 202 patients with AAA underwent elective endovascular aneurysm repair (EVAR) with implantation of a Zenith Alpha Abdominal in 7 centers. Early (30 day) outcomes in terms of technical and clinical success were assessed. Estimated 5 year outcomes were evaluated in terms of survival, freedom from type I/III endoleak, freedom from surgical conversion, freedom from limb graft occlusion, freedom from any device-related reintervention, and graft infection evaluation by life-table analysis (Kaplan-Meier test). A comparative analysis between different limb configurations (Zenith Spiral Z AAA iliac legs, codes ZISL vs ZSLE) was performed in terms of limb graft occlusion. The 30 day technical and clinical success rates were 97.5% and 99.5%, respectively. Median follow-up period was 25.5 months (interquartile range [IQR]: 12-43.25). The 5 year survival rate was 73.6%. The estimated 5 year outcomes in terms of freedom from type I/III endoleak, freedom from surgical conversion, freedom from limb graft occlusion, freedom from any device-related reintervention, and freedom from graft infection were 88.6% (95% CI [confidence interval]: 83.4%-93.1%), 95.8% (95% CI: 92.7%-97.1%), 93.6% (95% CI: 90.2%-96.8%), 87% (95% CI: 83.3%-91.6%), and 97.7% (95% CI: 95.1%-98.9%), respectively. About limb configuration, no differences were found in terms of 5 year freedom from limb graft occlusion (ZSLE 93.4% [95% CI: 89.8%-95.5%] vs ZISL 94.3% [95% CI: 90.1%-95.9%], p=0.342; log-rank 0.903). Zenith Alpha Abdominal in elective EVAR offered satisfactory early and 5 year outcomes with low complication rates. Limb graft occlusion continued to be an issue. Limb configuration did not affect outcomes. The authors describe satisfactory early and 5 year outcomes of Zenith Alpha Abdominal in elective endovascular aortic repair in the framework of a multicenter regional retrospective registry. At 5 years freedom from type I endoleak was 88.6%, and rate of endograft infections and conversions to open repair were very low. in the present study. Hot topic about about Zenith stent-graft still remains the limb graft occlusion with a 30-day overall rate of 2%, and estimated 5-year freedom from limb graft occlusion of 93.6%. Limb graft configuration did not affect limb graft occlusion rate. A standardized protocol including iliac stenting should be adopted to reduce kimb graft occlusion.

Variability of [18F]FDG-PET/LDCT reporting in vascular graft and endograft infection

Purpose18F-fluoro-D-deoxyglucose positron emission tomography with low dose and/or contrast enhanced computed tomography ([18F]FDG-PET/CT) scan reveals high sensitivity for the diagnosis of vascular graft and endograft infection (VGEI), but lower specificity. Reporting [18F]FDG-PET/CT scans of suspected VGEI is challenging, reader dependent, and reporting standards are lacking. The aim of this study was to evaluate variability of [18F]FDG-PET/low dose CT (LDCT) reporting of suspected VGEI using a proposed standard reporting format.MethodsA retrospective cohort study was conducted including all patients with a suspected VGEI (according to the MAGIC criteria) without need for urgent surgical treatment who underwent an additional [18F]FDG-PET/LDCT scan between 2006 and 2022 at a tertiary referral centre. All [18F]FDG-PET/LDCT reports were scored following pre-selected criteria that were formulated based on literature and experts in the field. The aim was to investigate the completeness of [18F]FDG-PET/LDCT reports for diagnosing VGEI (proven according to the MAGIC criteria) and to evaluate if incompleteness of reports influenced the diagnostic accuracy.ResultsHundred-fifty-two patients were included. Median diagnostic interval from the index vascular surgical procedure until [18F]FDG-PET/LDCT scan was 35.5 (7.3–73.3) months. Grafts were in 65.1% located centrally and 34.9% peripherally. Based on the pre-selected reporting criteria, 45.7% of the reports included all items. The least frequently assessed criterion was FDG-uptake pattern (40.6%). Overall, [18F]FDG-PET/LDCT showed a sensitivity of 91%, a specificity of 72%, and an accuracy of 88% when compared to the gold standard (diagnosed VGEI). Lower sensitivity and specificity in reports including ≤ 8 criteria compared to completely evaluated reports were found (83% and 50% vs. 92% and 77%, respectively).ConclusionLess than half of the [18F]FDG-PET/LDCT reports of suspected VGEI met all pre-selected criteria. Incompleteness of reports led to lower sensitivity and specificity. Implementing a recommendation with specific criteria for VGEI reporting is needed in the VGEI-guideline update. This study provides a first recommendation for a concise and complete [18F]FDG-PET/LDCT report in patients with suspected VGEI.

An autopsy case of infective aortic aneurysm with Pasteurella multocida infection: clinicopathological appearance and a review of literatures

Here, we showed our clinicopathological findings of infected aortic aneurysm (IAA) with Pasteurella multocida, which is a Gram-negative coccobacillus and is part of the normal oral flora of many animals. The patient was a 76-year-old male animal owner with a history of diabetes mellitus, alcoholic liver damage, and laryngeal cancer. He died 16 days after admission without undergoing operation because of poor general condition. Autopsy showed saccular outpouching with loss of the existing aortic wall and marked neutrophilic infiltration in the suprarenal abdominal aorta. Rupture was not evident. A polymerase chain reaction assay using DNA extracted from formalin-fixed paraffin-embedded specimen of the aneurysmal wall detected the Pasteurella multocida gene, therefore we conclude that the present case was IAA of native aorta with Pasteurella multocida infection. A review of the literature showed that IAA of native aorta with Pasteurella multocida infection is opportunistic and that liver disorder, alcohol addiction, diabetes mellitus, and animal bite may increase its risk. On the other hand, aortic endograft infection with Pasteurella multocida frequently occurred without an immunocompromised state. Pasteurella multocida may be a distinct causative microorganism in IAA, and/or sepsis when the participant is an animal owner.

How to combine CTA, 99mTc-WBC SPECT/CT, and [18F]FDG PET/CT in patients with suspected abdominal vascular endograft infections?

PurposeWe aimed at comparing 99mTc-HMPAO white blood cells (99mTc-WBC) scintigraphy, 18fluorine-fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) and CT angiography (CTA) in patients with suspected abdominal vascular graft or endograft infection (VGEI). Moreover, we attempted to define a new visual score for interpreting [18F]FDG PET/CT scans aiming at increasing its specificity.MethodsWe prospectively compared 99mTc-WBC SPECT/CT, [18F]FDG PET/CT, and CTA in 26 patients with suspected abdominal VGEI. WBC scans were performed and interpreted according to EANM recommendations. [18F]FDG PET/CT studies were assessed with both qualitative (Sah’s scale and new visual score) and semi-quantitative analyses. CTA images were interpreted according to MAGIC criteria. Microbiology, histopathology or a clinical follow-up of at least 24 months were used to achieve final diagnosis.ResultsEleven out of 26 patients were infected. [18F]FDG PET/CT showed 100% sensitivity and NPV, with both scoring systems, thus representing an efficient tool to rule out the infection. The use of a more detailed scoring system provided statistically higher specificity compared to the previous Sah’s scale (p = 0.049). 99mTc-WBC SPECT/CT provided statistically higher specificity and PPV than [18F]FDG PET/CT, regardless the interpretation criteria used and it can be, therefore, used in early post-surgical phases or to confirm or rule out a PET/CT finding.ConclusionsAfter CTA, patients with suspected late VGEI should perform a [18F]FDG PET/CT given its high sensitivity and NPV. However, given its lower specificity, positive results should be confirmed with 99mTc-WBC scintigraphy. The use of a more detailed scoring system reduces the number of 99mTc-WBC scans needed after [18F]FDG PET/CT. Nevertheless, in suspected infections within 4 months from surgery, 99mTc-WBC SPECT/CT should be performed as second exam, due to its high accuracy in differentiating sterile inflammation from infection.

Semi-Conservative Treatment Versus Radical Surgery in Abdominal Aortic Graft and Endograft Infections

Abdominal aortic graft and endograft infections (AGIs) are rare complications following aortic surgery. Radical surgery (RS) with resection of the infected graft and reconstruction with extra-anatomical bypass or in situ reconstruction is the preferred therapy. For patients unfit for RS, a semi-conservative (SC), graft preserving strategy is possible. This paper aimed to compare survival and infection outcomes between RS and SC treatment for AGI in a nationwide cohort. Patients with abdominal AGI related surgery in Sweden between January 1995 and May 2017 were identified. The Management of Aortic Graft Infection Collaboration (MAGIC) criteria were used for the definition of AGI. Multivariable regression was performed to identify factors associated with mortality. One hundred and sixty-nine patients with surgically treated abdominal AGI were identified, comprising 43 SC (14 endografts; 53% with a graft enteric fistula [GEF] in total) and 126 RS (26 endografts; 50% with a GEF in total). The SC cohort was older and had a higher frequency of cardiac comorbidities. There was a non-significant trend towards lower Kaplan-Meier estimated five year survival for SC vs. RS (30.2% vs. 48.4%; p= .066). A non-significant trend was identified towards worse Kaplan-Meier estimated five year survival for SC patients with a GEF vs. without a GEF (21.7% vs. 40.1%; p= .097). There were significantly more recurrent graft infections comparing SC with RS (45.4% vs. 19.3%; p < .001). In a Cox regression model adjusting for confounders, there was no difference in five year survival comparing SC vs. RS (HR 1.0, 95% CI 0.6 - 1.5). In this national AGI cohort, there was no mortality difference comparing SC and RS for AGI when adjusting for comorbidities. Presence of GEF probably negatively impacts survival outcomes of SC patients. Rates of recurrent infection remain high for SC treated patients.

Performance of the BioIntegral Bovine Pericardial Graft in Vascular Infections: VASCular No-REact Graft Against INfection Study

Vascular graft and endograft infections (VGEI) and native vessel infections (NVI) remain considerable challenges in vascular surgery, leading to high mortality and morbidity rates. Although in situ reconstruction is the preferred treatment, the material of choice is still a source of debate. Autologous veins are considered the first choice; however, xenografts may be an acceptable alternative. The performance of a biomodified bovine pericardial graft is assessed when implemented in an infected vascular area. This is a prospective multicenter cohort study. Patients who underwent reconstruction for VGEI or NVI with a biomodified bovine pericardial bifurcated or straight tube graft were included from December 2017 until June 2021. The primary outcome measure was reinfection at mid-term follow-up. Secondary outcome measures included mortality, patency, and amputation rate. Thirty-four patients with vascular infections were included, of which 23 (68%) had an infected Dacron prosthesis after primary open repair and 8 (24%) had an infected endovascular graft. The remaining 3 (9%) had infected native vessels. At secondary repair, 3 (7%) patients had an in situ aortic tube reconstruction, 29 (66%) had an aortic bifurcated reconstruction, and 2 (5%) had an iliac-femoral reconstruction. At 1-year follow-up after the BioIntegral bovine pericardial graft reconstruction, the reinfection rate was 9%. The 1-year infection-related and procedure-related mortality rate was 16%. The occlusion rate was 6% and in total 3 patients underwent a lower limb amputation during the 1-year follow-up period. In situ reconstruction as treatment of (endo)graft and native vessel infections remains a challenge and reinfection looms as a potential consequence. In cases where time is of essence or when autologous venous repair is not feasible, a swift available solution is needed. The BioIntegral biomodified bovine pericardial graft may be an option as it shows reasonable results in terms of reinfection, in aortic tube and bifurcated grafts.

Use of Omniflow® II Biosynthetic Graft for the Treatment of Vascular Graft and Endograft Infections

Vascular graft/endograft infection is a rare but life-threatening complication of cardiovascular surgery and remains a surgical challenge. Several different graft materials are available for the treatment of vascular graft/endograft infection, each having its own advantages and disadvantages. Biosynthetic vascular grafts have shown low reinfection rates and could be a potential second best after autologous veins in the treatment of vascular graft/endograft infection. Therefore, the aim of our study was to evaluate the efficacy and morbidity of Omniflow® II for the treatment of vascular graft/endograft infection. A multicenter retrospective cohort study was performed to evaluate the use of Omniflow® II in the abdominal and peripheral region to treat vascular graft/endograft infection between January 2014 and December 2021. Primary outcome was recurrent vascular graft infection. Secondary outcomes included primary patency, primary assisted patency, secondary patency, all-cause mortality, and major amputation. Fifty-two patients were included with a median follow-up duration of 26.5 (10.8-54.8) months. Nine (17%) grafts were implanted in intracavitary position and 43 (83%) in peripheral position. Most grafts were used as femoral interposition (n=12, 23%), femoro-femoral crossover (n=10, 19%), femoro-popliteal (n=8, 15%), and aorto-bifemoral (n=8, 15%) graft. Fifteen (29%) grafts were implanted extra-anatomically and 37 (71%) in situ. Eight patients (15%) presented with reinfection during follow-up, most of these patients received an aorto-bifemoral graft (n=3, 38%). Intracavitary vascular grafting had a 33% (n=3) reinfection rate and peripheral grafting 12% (n=5; p=0.025). The estimated primary patencies at 1, 2, and 3 years were 75%, 72%, and 72% for peripherally located grafts and 58% (at all timepoints) for intracavitary grafts (p=0.815). Secondary patencies at 1, 2, and 3 years were 77% (at all timepoints) for peripherally located prostheses and 75% (at all timepoints) for intracavitary prostheses (p=0.731). A significantly higher mortality during follow-up was observed in patients who received a intracavitary graft compared to patients with a peripheral graft (p=0.003). This study highlights the efficacy and safety of the Omniflow® II biosynthetic prosthesis for the treatment of vascular graft/endograft infection, in absence of suitable venous material, with acceptable reinfection, patency, and freedom of amputation prevalences, especially in replacing peripheral vascular graft/endograft infection. However, a control group with either venous reconstruction or another alternative graft is needed to make firmer conclusions.

Primary Aortic Endograft Infections Have Worse Outcomes Compared to Infections Involving Aortic Surgical Grafts or Primary Mycotic Aortic Infections

Aortic infection is associated with high morbidity and mortality, but the outcomes of prosthetic (surgical or endovascular) grafts compared to primary aortic infections are poorly defined. This large single-center retrospective study aims to compare the outcomes of primary and prosthetic aortic graft infections. Patients diagnosed with primary or infected aortic grafts between January 2000 and December 2022 were included. Patients were group based on the infection type (primary, surgical graft and endograft). Baseline demographics, symptoms, imaging, interventions, and outcomes were evaluated. Primary outcomes included overall and reintervention-free survival. Kaplan-Meier survival and Cox proportional hazards analysis were performed. A total of 145 patients presented during the study period with infections of the native aorta (34.5%) and aortic graft (65.5%). Baseline characteristics and treatments are summarized in the Table. In-hospital mortality (36.7% vs 15.4% vs 10%; P = .01) and 30-day complication rates (67% vs 40% vs 38%; P = .03) were highest among endografts, followed by surgical grafts, and lowest among primary infections respectively. Primary aortic infections had the highest 30-day, 1-year, and 5-year survival on Kaplan-Meier analysis compared to surgical and endograft infections (Figure). Reintervention-free survival was also highest in primary infections at 1 and 5 years (log-rank P < .001), while no difference was found at 30 days. On multivariate analysis, infected surgical grafts and endografts were associated with a significantly higher 30-day mortality (hazard ratio [HR], 9.18; P = .015 and HR 7.58; P = .02, respectively). Visceral artery involvement or isolated groin infections did not influence mortality at any timepoint nor did treatment type (in situ repair vs extra-anatomical vs endovascular), while gram-positive tissue cultures were associated with higher 30-day and 1-year mortality (HR, 17.6; P = .01 and HR 4.14; P = .004, respectively) when compared to patients who had no growth on tissue cultures. There was no difference in the duration of intravenous antibiotic treatment between groups (42 vs 45 vs 44 days; P = .84). Infected aortic endografts have lower short and long-term survival independent of treatment type as well as a lower rate of long-term intervention-free survival when compared to surgical graft and primary aortic infections. Gram positive intraoperative cultures were associated with increased mortality. Predictors of endograft infection need to be determined to minimize complications and careful consideration is necessary before employing endovascular interventions if there is concern an underlying mycotic process.TableBaseline demographics, presenting symptoms, and treatmentsPrimary infections, n = 50 (34.5%)Surgical grafts, n = 65 (44.8%)Endografts, n = 30 (20.7%)P valuePrior aortic pathology Aneurysmal disease26 (40%)27 (90%)<.001 Occlusive disease8 (12%)1 (3%) Other (dissection)5 (8%)1 (3%) Unknown26 (40%)1 (3%)Visceral involvement8 (16.3%)5 (7.8%)3 (9.7).35Infected graft location Groin4 (6.3%)0 (0%).01 Abdomen38 (59.4%)28 (93.4%) Abdomen + groin15 (23.4%)1 (3.3%) Chest7 (10.9%)1 (3.3%)Age, mean (SD)64.9 (9.1)67.8 (10.9)73.1 (10.5).003Gender Male34 (68%)42 (65%)26 (87%).078 Female16 (32%)23 (35%)4 (13%)Race Non-Hispanic White44 (88%)61 (94%)24 (80%).059 Black5 (10%)1 (2%)2 (7%) Other1 (2%)3 (5%)4 (13%)History of peripheral artery disease2 (4%)31 (48%)9 (30%)<.001Diabetes15 (30%)9 (14%)3 (10%).046End-stage renal disease4 (8%)1 (2%)3 (10%).13Hypertension36 (72%)48 (74%)19 (63%).56Coronary artery disease15 (30%)19 (29%)16 (53%).060Recent infection (3 weeks)24 (48%)15 (23%)6 (20%).007Recent surgery (3 weeks)1 (2%)8 (12%)3 (10%).11Antibiotics on presentation2 (4%)17 (26%)9 (30%).001Abdominal pain30 (60%)21 (32%)11 (37%).010Back pain26 (52%)6 (9%)10 (33%)<.001Groin symptoms0 (0%)15 (23%)2 (7%)<.001Fever2 (4%)8 (12%)10 (33%).002Rupture on computed tomography26 (53%)3 (6%)3 (11%)<.001Surgical/tissue culture results Fungal0 (0%)2 (5%)1 (4%).015 Gram negative4 (13%)9 (21%)1 (4%) Gram positive10 (32%)7 (17%)9 (36%) Mixed0 (0%)7 (17%)6 (24%) No growth17 (55%)17 (40%)8 (32%)Blood culture results Fungal0 (0%)1 (2%)0 (0%).017 Gram negative4 (9%)2 (4%)2 (7%) Gram positive15 (34%)5 (9%)6 (22%) No growth25 (57%)47 (85%)19 (70%)Antibiotics given21 (42%)64 (98%)30 (100%)<.001Antibiotic duration, median (IQR), days42 (9, 96)45 (30, 61)44 (29, 52).84Intraoperative purulence noted0 (0%)27 (55%)25 (100%)<.00130-day complications19 (38%)26 (40%)20 (67%).02830-Day readmission12 (27%)11 (19%)3 (11%).29Treatment Open in situ repair18 (36%)13 (20%)7 (23%).007 Extra-anatomical bypass15 (30%)31 (48%)16 (53%) Endovascular16 (32%)8 (13%)1 (3%) Medical0 (0%)5 (8%)3 (10%) Palliative0 (0%)2 (3%)1 (3%) Other (debridement)1 (2%)5 (8%)2 (8%)Recurrent infections3 (33.3%)6 (27.3%)1 (14.3%).6830-Day survival44 (89.8%)52 (89%)21 (66.7%).041-Year survival35 (73.3%)41 (69.1%)10 (36.7%)<.0015-Year survival20 (58.8%)22 (42.8%)10 (36.7%).0230-Day reintervention-free survival41 (83.7%)45 (61.4%)19 (62.7%).121-Year reintervention-free survival31 (65.1%)31 (52.3%)5 (20.7%)<.0015-Year reintervention-free survival16 (48.3%)15 (27.1%)2 (16.5%)<.001 Open table in a new tab

Conservative Management First Strategy in Aortic Vascular Graft and Endograft Infections

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. 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. 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. 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.

Sonication of Vascular Grafts and Endografts to Diagnose Vascular Graft Infection: a Head-To-Head Comparison with Conventional Culture and Its Clinical Impact.

Vascular graft and endograft infection (VGEI) is a severe complication associated with high mortality and is often challenging to diagnose. For the definitive microbiological diagnosis, sonication of vascular grafts may increase the microbiological yield of these biofilm-associated infections. The objective of this study was to determine whether sonication of explanted vascular grafts and endografts results in a higher diagnostic accuracy than conventional culture methods and aids in clinical decision-making. A prospective diagnostic study was performed comparing conventional culture with sonication culture of explanted vascular grafts in patients treated for VGEI. Explanted (endo)grafts were cut in halves and were either subjected to sonication or conventional culture. Criteria based on the Management of Aortic Graft Infection Collaboration (MAGIC) case definition of VGEI were used for definitive diagnosis. The relevance of sonication cultures was assessed by expert opinion to determine the clinical impact on decision-making. Fifty-seven vascular (endo)graft samples from 36 patients (four reoperations; 40 episodes) treated for VGEI were included; 32 episodes were diagnosed with VGEI. Both methods showed a positive culture in 81% of the cases. However, sonication culture detected clinically relevant microorganisms that went unnoticed by conventional culturing in 9 out of 57 samples (16%, 8 episodes) and provided additional relevant information regarding growth densities in another 11 samples (19%, 10 episodes). Sonication of explanted vascular grafts and endografts improves the microbiological yield and aids in the clinical decision-making for patients with a suspected VGEI compared to conventional culture alone. IMPORTANCE Sonication culture of explanted vascular grafts was shown to be a noninferior method compared to conventional culturing in diagnosing vascular graft and endograft infection (VGEI). Moreover, sonication culture has probable additional value in microbiological characterization of VGEI by giving more detailed information on growth densities, especially when the conventional culture shows intermediate growth. In this prospective design, for the first time, a direct comparison is made between sonication culturing and conventional culturing in VGEI, while taking clinical interpretation into account. Therefore, this study is another step toward a more accurate microbiological diagnosis of VGEI, influencing clinical decision-making.