Editor's Choice - European Society for Vascular Surgery (ESVS) 2020 Clinical Practice Guidelines on the Management of Vascular Graft and Endograft Infections

Conservative Management First Strategy in Aortic Vascular Graft and Endograft Infections

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Vascular Complications in Coxiella burnetii Infection: A Report of Two Cases

Introduction

First described in 1937, Q fever remains a relatively new disease, with much to be learned about its presentation and diagnosis. Due to its role in the development of aortic aneurysms and vascular graft infections, its implications in the vascular domain have become increasingly reported. This is a report of two cases of vascular complications associated with Coxiella burnetii infection, and the challenges in managing their unique presentations.

Reports

Case 1: A 70 year old man with a prosthetic aortobiiliac graft and past Q fever infection presented with acute sepsis. Abdominal computed tomography (CT) showed soft tissue thickening and stranding around the graft, and locules of gas within the vessel. Pelvic magnetic resonance imaging (MRI) revealed a chain of abscesses within the right gluteal region, of which aspirate grew Prevotella oris and Escherichia coli. Open explanation of the aortic graft and replacement by superficial femoral vein was performed. Tissue culture confirmed a polymicrobial infection, and PCR of the aortic wall and pre-aortic lymph node was positive for Q fever. He was treated for recrudescent Q fever infection with a good outcome and recovery. Case 2: A 73 year old man had an incidental abdominal aortic aneurysm (AAA) identified at the time of Q fever diagnosis. Following an incomplete course of doxycycline and hydroxychloroquine, the aneurysm rapidly progressed, leading to presentation with right flank pain. Fluorodeoxyglucose (FDG) positron emission tomography (PET) showed multiple foci of uptake within the aneurysm wall. Open AAA repair with a polyester graft was performed, with AAA tissue positive for Q fever on PCR. The operation was successful, with the patient continuing clearance therapy at time of writing.

Discussion

Q fever infection poses serious implications for patients with vascular grafts and AAAs, and thus, should be considered in the differential diagnosis of mycotic aortic aneurysms and in aortic graft infections.

A Narrative Review of Experimental Assessment to Study Vascular Biomaterials Infections and Infectability

Objective

Many experimental studies have been conducted to evaluate vascular and endovascular graft infections (VGEIs) and infectability in order to elaborate strategies to prevent or to treat their occurrence. A systematic literature search was conducted to collect and summarise key features of infection and infectability assessment techniques in VGEI experimental models.

Methods

The literature search was conducted using the Medline and Cochrane databases, with no limit on the date of publication, until 10 August 2021. Ex vivo, in vitro, and in vivo animal studies on VGEIs, published in English or French, were selected. Cross references retrieved from selected articles on PubMed database were also included in the search. Data were collected on the techniques and the protocols performed for vascular graft infection and infectability assessment.

Results

A total of 243 studies were included in the review: 55 in vitro studies, 169 animal studies, 17 combining the two models, and two ex vivo studies. Many experimental techniques were performed, with a lot of protocol discrepancies. The main experiments conducted were bacterial culture, with (n = 82 studies) or without sonication (n = 120), histopathology (n = 69), scanning electron microscopy (n = 36), and graft diffusion tests (n = 28). These techniques were used to answer different research questions corresponding to different graft infection steps, such as microbial adhesion and/or viability, biofilm biomass or organisation, human cell reaction, or antimicrobial activity.

Conclusion

Many experimental tools are available to study VGEIs, but to improve their reproducibility and scientific reliability research protocols must be standardised and include sonication of grafts before microbiological culture. Moreover, the key role of the biofilm in VGEI physiopathology must be taken into account in future studies.

American Society of Anesthesiologists-Physical Status Classification As An Independent Risk Factor of Surgical Site Infection After Infra-Inguinal Arterial Bypass

OBJECTIVES

The present study aimed to assess whether high-risk American Society of Anesthesiologists (ASA)-Physical Status was an independent risk factor for the development of surgical site infection (SSI) after infra-inguinal lower extremity bypass (LEB).

SUMMARY OF BACKGROUND DATA

The ASA-Physical Status Classification System assesses the overall physical status preoperatively. ASA-Physical Status is associated with postoperative morbidity and mortality. However, limited data are available on how ASA-Physical Status Class affects the development of SSI after infra-inguinal LEB.

METHODS

Patients who had undergone infra-inguinal LEB from January 1, 2015 to December 31, 2018, for obliterative arteriopathy or popliteal aneurysm at our university hospital were included. SSI risk factors were identified using multivariable logistic regression. The length of hospital stay, major limb events (MALE), major adverse cardiovascular events (MACE), and all-cause mortality were compared for patients with SSI versus those without SSI 3 months and 1- year of follow-up after the index surgery.

RESULTS

Among the 267 patients included, 30 (11.2%) developed SSI during the 3-month period and 32 (12%) at 1 year. ASA-Physical Status ≥3 [odds ratio (OR): 3.7, 95% confidence interval CI) 1.5-11.1], emergency surgery (OR: 2.7, 95% CI 1.2-6.0), general anesthesia (OR: 2.8, 95% CI 1.3-6.1), and procedure performed by a junior surgeon (OR: 2.7, 95% CI 1.3-6.0) were independently associated with SSI. At 3 months and 1 year, SSI was significantly associated with MALE (including surgical wound debridement, subsequent thrombectomy, major amputation), length of hospital stay, and all-cause mortality.

CONCLUSION

The ASA-Physical Status should be considered in medical management when an infra-inguinal LEB is considered in frail patients, to prevent surgical complications.

Reconstruction of primary and secondary aortic infections with an antimicrobial graft

INTRODUCTION

In situ reconstruction (ISR) with autologous veins is the preferred method in infectious native aortic aneurysms (INAAs) or vascular (endo)graft infection (VGEI). However, access to biological substitutes can prove difficult and lacks versatility. This study evaluates survival and freedom from reinfection after ISR of INAA/VGEI using the antimicrobial Intergard Synergy graft combining silver and triclosan.

METHODS

From February 2014 to April 2020, 86 antimicrobial grafts were implanted for aortic infection. The diagnosis of INAA/VGEI and reinfection was established based on the Management of Aortic Graft Infection Collaboration criteria. Survival was analyzed using the Kaplan-Meier method and log-rank P values.

RESULTS

The antimicrobial graft was implanted in 32 cases of INAA, 28 of VGI, and 26 of VEI. The median age was 69.0 (interquartile range: 62.0; 74.0), with a history of coronary artery disease (n = 21; 24.4%), chronic kidney disease (n = 11; 12.8%), cancer (n = 21; 24.4%), and immunosuppression (n = 27; 31.4%). Imaging showed infiltration (n = 14; 16.3%), air (n = 10; 11.6%), and rupture (n = 16; 18.6% including 22 aortoenteric fistulae [AEnF]). Symptoms included fever (n = 37; 43.0%), shock (n = 11; 12.8%), and pain (n = 47; 54.7%). Repair was undertaken through a midline laparotomy in 75 cases (87.2%) and coeliac cross-clamping in 19 (22.1%), suprarenal in 26 (30.2%), plus celiac trunk (n = 3), mesenteric (n = 5), renal (n = 13), or hypogastric (n = 4) artery reconstruction, and omental flap coverage (n = 41; 48.8%). For AEnF, the gastrointestinal tract was repaired using direct suture (n = 14; 16.3%) or resection anastomosis (n = 8; 9.3%). Causative organisms were identified in 74 patients (86.0%), with polymicrobial infection in 32 (37.2%) and fungal coinfection in 7 (8.1%). Thirty-day and in-hospital mortality were 14.0% and 22.1% (n = 12 and 19, respectively, 3 INAA [9.4%], 7 VGI [25.0%], and 9 VEI [34.6%]). Seventy patients (81.4%) had a postoperative complication, 44 (51.2%) of whom returned to the operative room. The 1- and 2-year survival rates were 74.0% (95% confidence interval [CI]: 63.3-82.1) and 69.8% (95% CI: 58.5-78.5), respectively. Survival was significantly better for INAA vs VGEI (P = .01) and worse for AEnF (P = .001). Freedom from reinfection was 97.2% (95% CI: 89.2-99.3) and 95.0% (95% CI: 84.8-98.4) with six reinfections (7.0%) requiring two radiological/six surgical drainage and two graft removals. Primary patency was 88.0% (95% CI: 78.1-93.6) and 79.9% (95% CI: 67.3-88.1) with no significant difference between INAA and VGEI (P = .16).

CONCLUSIONS

ISR of INAA or VGEI with the antimicrobial graft showed encouraging early mortality, comparable to the rates found in femoral vein (9%-16%) and arterial allograft (8%-28%) studies, as well as mid-term reinfection. The highest in-hospital mortality was noted for VEI including nearly 50% of AEnF.

Systematic review of groin wound surgical site infection incidence after arterial intervention

The objectives were to determine the surgical site infection incidence (including superficial/deep) fter arterial intervention through non-infected groin incisions and identify variables associated with incidence. MEDLINE, EMBASE and CENTRAL databases were searched for randomised controlled trials and observational studies of adults undergoing arterial intervention through a groin incision and reported surgical site infection. Infection incidence was examined in subgroups, variables were subjected to meta-regression. One hundred seventeen studies reporting 65 138 groin incisions in 42 347 patients were included. Overall surgical site infection incidence per incision was 8.1% (1730/21 431): 6.3% (804/12 786) were superficial and 1.9% (241/12 863) were deep. Superficial infection incidence was higher in randomised controlled trials (15.8% [278/1762]) compared with observational studies (4.8% [526/11 024]); deep infection incidence was similar (1.7% (30/1762) and 1.9% (211/11 101) respectively). Aneurysmal pathology (β = -10.229, P < .001) and retrospective observational design (β = -1.118, P = .002) were associated with lower infection incidence. Surgical site infection being a primary outcome was associated with a higher incidence of surgical site infections (β = 3.429, P = .017). The three-fold higher incidence of superficial surgical site infection reported in randomised controlled trials may be because of a more robust clinical review of patients. These results should be considered when benchmarking practice and could inform future trial design.

Editor's Choice - Infective Native Aortic Aneurysms: A Delphi Consensus Document on Terminology, Definition, Classification, Diagnosis, and Reporting Standards

OBJECTIVE

There is no consensus regarding the terminology, definition, classification, diagnostic criteria, and algorithm, or reporting standards for the disease of infective native aortic aneurysm (INAA), previously known as mycotic aneurysm. The aim of this study was to establish this by performing a consensus study.

METHODS

The Delphi methodology was used. Thirty-seven international experts were invited via mail to participate. Four two week Delphi rounds were performed, using an online questionnaire, initially with 22 statements and nine reporting items. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements revised, and results presented in iterative rounds. Consensus was defined as ≥ 75% of the panel selecting "strongly agree" or "agree" on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha coefficient > .80.

RESULTS

All 38 panellists completed all four rounds, resulting in 100% participation and agreement that this study was necessary, and the term INAA was agreed to be optimal. Three more statements were added based on the results and comments of the panel, resulting in a final 25 statements and nine reporting items. All 25 statements reached an agreement of ≥ 87%, and all nine reporting items reached an agreement of 100%. The Cronbach's alpha increased for each consecutive round (round 1 = .84, round 2 = .87, round 3 = .90, and round 4 = .92). Thus, consensus was reached for all statements and reporting items.

CONCLUSION

This Delphi study established the first consensus document on INAA regarding terminology, definition, classification, diagnostic criteria, and algorithm, as well as reporting standards. The results of this study create essential conditions for scientific research on this disease. The presented consensus will need future amendments in accordance with newly acquired knowledge.

A systematic review and meta-analysis of the use of the Omniflow II biosynthetic graft for aortic reconstruction

OBJECTIVE

Despite the improvements in xenogeneic grafts and surgical techniques, management of aortic graft infection has remained challenging. The optimal graft material has remained controversial, with high rates of reinfection using prosthetic grafts and a limited time for venous harvest in an emergent setting. Recent studies have highlighted an increase in the use of Omniflow II biosynthetic vascular grafts (LeMaitre Vascular, Burlington, MA) for aortic reconstruction. The primary aim of the present study was to review the key outcomes for the Omniflow II graft in terms of reinfection and complications.

METHODS

The National Healthcare Service healthcare databases advanced search function was used to search nine databases for the search term "Omniflow." The present study complied with the PRISMA (preferred reporting items for systematic review and meta-analysis) statement. Eligible studies related to aortic graft infection or in situ aortic reconstruction were selected in accordance with prespecified eligibility criteria and included for review. Data on the surgical technique, comorbidities, graft reinfection, mortality, and complications were combined. The data were analyzed using Stata/MP, version 17 (StataCorp, College Station, TX), and the probabilities were pooled using a DerSimonian and Laird random effects model with Freeman-Tukey arcsine transformation.

RESULTS

Six studies with 60 patients (44 men; age range, 29-89 years) were included. Of the 60 patients, 25 had undergone surgical reconstruction because of early graft infection (<4 months after the index procedure), 24 for late graft infection, and 3 because of mycotic aneurysms. Eight high-risk patients had undergone surgical reconstruction for prevention of an initial graft infection. Staphylococcus aureus, Escherichia coli, and S. epidermis were the most common organisms. Early mortality was 8.83% (95% confidence interval [CI], 1.12%-20.53%), and late mortality was 18.49% (95% CI, 5.51%-35.34%). Follow-up varied from 9 months to 2 years. No graft rupture or graft degeneration had occurred during follow-up. However, 6.2% (95% CI, 0.39%-15.81%) had experienced early graft occlusion, and 3.83% (95% CI, 0.00%-16.34%) had developed early graft stenosis. Two cases of postoperative reinfection were reported. The freedom from reinfection was 97.71% (95% CI, 87.94%-100.00%).

CONCLUSIONS

Use of the Omniflow II graft for aortic reconstruction is a feasible alternative with acceptable mortality and low reinfection rates. However, there is a risk of limb occlusion. Although these studies were of low quality, the Omniflow II graft shows promise in this difficult patient cohort, especially when bifurcated reconstruction is required.

Abdominal aortic endograft infection. A decade of experience and literature review

INTRODUCTION

Aortic endograft infection is an infrequent but life-threatening complication after endovascular abdominal aortic repair (EVAR). There is no consensus on management of endograft infection and little evidence has been published in our country. Endograft explantation is considered the "gold standar" treatment whereas percutaneous or surgical perigraft and sac drainage associated to antibiotics should be considered and alternative therapy.

METHODS

We carried out a retrospective and descriptive review of abdominal aortic endograft infections at our tertiary center (Hospital Universitario Cruces) during last ten years (2010-2019).

RESULTS

We describe the clinical and microbiological characteristics of 10 EVAR infections, their management and outcomes. The incidence of graft infection after EVAR was 3%. The mean time to the clinical presentation of infection was 16.9 months (median 4.5 months). The microbiological diagnosis was reached in 100% of cases (predominance of gram-positive species). The overall mortality rate was 50% (although the survival rate was 100% after surgical drainage of the sac).

CONCLUSION

Perigraft or aneurysm sac aspiration culture show their diagnostic utility as microbiological diagnosis was reached in all cases despite of blood cultures being only positive in 50% of the samples. Surgical drainage and endograft preservation combined with antibiotherapy show remarkable results. The high heterogeneity in our case series makes difficult to offer general recommendations, thus far, a tailored approach to treatment is suggested.

Multicenter Retrospective Study of Vascular Infections and Endocarditis Caused by Campylobacter spp., France

The incidence of campylobacteriosis has substantially increased over the past decade, notably in France. Secondary localizations complicating invasive infections are poorly described. We aimed to describe vascular infection or endocarditis caused by Campylobacter spp. We included 57 patients from a nationwide 5-year retrospective study on Campylobacter spp. bacteremia conducted in France; 44 patients had vascular infections, 12 had endocarditis, and 1 had both conditions. Campylobacter fetus was the most frequently involved species (83%). Antibiotic treatment involved a β-lactam monotherapy (54%) or was combined with a fluoroquinolone or an aminoglycoside (44%). The mortality rate was 25%. Relapse occurred in 8% of cases and was associated with delayed initiation of an efficient antimicrobial therapy after the first symptoms, diabetes, and coexistence of an osteoarticular location. Cardiovascular Campylobacter spp. infections are associated with a high mortality rate. Systematically searching for those localizations in cases of C. fetus bacteremia may be warranted.

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.

Three-Year Patency Results following Endovascular Transvenous Femoropopliteal Bypass

Background and Objectives: Peripheral artery disease is one of the most common vascular pathologies. There is an ongoing debate among specialists on whether open or endovascular revascularization is preferred in cases of complex superficial femoral artery (SFA) lesions. The purpose of this study was to assess patency results of a relatively new transvenous endovascular bypass device. This could add to existing evidence and aid in comparison between open and endovascular bypass. Materials and Methods: Patients with complex TASC-C and D SFA lesions who had indications for revascularization were identified. Prospective analysis of stent graft patency from 54 transvenous femoropopliteal bypass procedures was performed. Patency was assessed by Duplex ultrasound every six months. Kaplan–Meier analysis was performed to assess primary, primary-assisted, and secondary patency of transvenous bypass. Results: Following endovascular transvenous femoropopliteal bypass, 3-year graft primary, primary-assisted, and secondary patency was 43.8%, 66.3%, and 73.9%, respectively. Conclusions: Transvenous endovascular femoropopliteal bypass is a viable option for selected patients who lack adequate saphenous vein or have comorbidities that increase the risk of open femoropopliteal bypass. Strict post-operative follow-up is necessary to improve patency rates.

Methicillin-Susceptible Staphylococcus aureus Biofilm Formation on Vascular Grafts: an In Vitro Study

The aim of this study was to quantify in vitro biofilm formation by methicillin-susceptible Staphylococcus aureus (MSSA) on the surfaces of different types of commonly used vascular grafts. We performed an in vitro study with two clinical strains of MSSA (MSSA2 and MSSA6) and nine vascular grafts: Dacron (Hemagard), Dacron-heparin (Intergard heparin), Dacron-silver (Intergard Silver), Dacron-silver-triclosan (Intergard Synergy), Dacron-gelatin (Gelsoft Plus), Dacron plus polytetrafluoroethylene (Fusion), polytetrafluoroethylene (Propaten; Gore), Omniflow II, and bovine pericardium (XenoSure). Biofilm formation was induced in two phases: an initial 90-minute adherence phase and a 24-hour growth phase. Quantitative cultures were performed, and the results were expressed as log10 CFU per milliliter. The Dacron-silver-triclosan graft and Omniflow II were associated with the least biofilm formation by both MSSA2 and MSSA6. MSSA2 did not form a biofilm on the Dacron-silver-triclosan graft (0 CFU/mL), and the mean count on the Omniflow II graft was 3.89 CFU/mL (standard deviation [SD] 2.10). The mean count for the other grafts was 7.01 CFU/mL (SD 0.82). MSSA6 formed a biofilm on both grafts, with 2.42 CFU/mL (SD 2.44) on the Dacron-silver-triclosan graft and 3.62 CFU/mL (SD 2.21) on the Omniflow II. The mean biofilm growth on the remaining grafts was 7.33 CFU/mL (SD 0.28). The differences in biofilm formation on the Dacron-silver-triclosan and Omniflow II grafts compared to the other tested grafts were statistically significant. Our findings suggest that of the vascular grafts we studied, the Dacron-silver-triclosan and Omniflow II grafts might prevent biofilm formation by MSSA. Although further studies are needed, these grafts seem to be good candidates for clinical use in vascular surgeries at high risk of infections due to this microorganism. IMPORTANCE The Dacron silver-triclosan and Omniflow II vascular grafts showed the greatest resistance to in vitro methicillin-susceptible Staphylococcus aureus biofilm formation compared to other vascular grafts. These findings could allow us to choose the most resistant to infection prosthetic graft.

Added Value of Abnormal Lymph Nodes Detected with FDG-PET/CT in Suspected Vascular Graft Infection

Vascular graft and endograft infections (VGEI) cause a serious morbidity and mortality burden. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) imaging is frequently used in the diagnostic workup, but the additional value of abnormal (¹⁸F-FDG active and/or enlarged) locoregional lymph nodes is unknown. In this retrospective study, the additional diagnostic value of abnormal locoregional lymph nodes on ¹⁸F-FDG PET/CT imaging for VGEI was evaluated, including 54 patients with a culture-proven VGEI (defined according to the Management of Aortic Graft Infection [MAGIC] group classification) and 25 patients without VGEI. ¹⁸F-FDG PET/CT was qualitatively and quantitatively assessed for tracer uptake and pattern at the location of the vascular graft, and locoregional lymph node uptake and enlargement (>10 mm). ¹⁸F-FDG uptake intensity and pattern independently predicted the presence of VGEI by logistic regression (Χ²: 46.19, p < 0.001), with an OR of 7.38 (95% CI [1.65, 32.92], p = 0.009) and 18.32 (95% CI [3.95, 84.88], p < 0.001), respectively. Single visual assessment of abnormal locoregional lymph nodes predicted the presence of VGEI with a sensitivity of 35%, specificity of 96%, PPV of 95%, and NPV of 41%. The visual assessment of abnormal lymph nodes after qualitative assessment of ¹⁸F-FDG uptake intensity and pattern at the vascular graft location did not independently predict the presence of VGEI by logistic regression (Χ²: 3.60, p = 0.058; OR: 8.25, 95% CI [0.74, 63.37], p = 0.096). In conclusion, detection of abnormal locoregional lymph nodes on ¹⁸F-FDG PET/CT has a high specificity (96%) and PPV (95%) for VGEI. However, it did not add to currently used ¹⁸F-FDG PET/CT interpretation criteria.

Infection of Vascular Prostheses: A Comprehensive Review

Vascular graft or endograft infection (VGEI) is a complex disease that complicates vascular-surgery and endovascular-surgery procedures and determines high morbidity and mortality. This review article provides the most updated general evidence on the pathogenesis, prevention, diagnosis, and treatment of VGEI. Several microorganisms are involved in VGEI development, but the most frequent one, responsible for over 75% of infections, is Staphylococcus aureus. Specific clinical, surgical, radiologic, and laboratory criteria are pivotal for the diagnosis of VGEI. Surgery and antimicrobial therapy are cornerstones in treatment for most patients with VGEI. For patients unfit for surgery, alternative treatment is available to improve the clinical course of VGEI.

Association Between the Lockdown for SARS-CoV-2 (COVID-19) and Reduced Surgical Site Infections after Vascular Exposure in the Groin at Two Italian Academic Hospitals

BACKGROUND

The aim of this study was to evaluate whether the scrupulous hygiene rules and the restriction of contacts during the lockdown owing to the COVID-19 pandemic affected the rate and severity of surgical site infections (SSI) after vascular exposure in the groin at two Italian University Hospitals.

METHODS

Starting from March 2020, strict hygiene measures for protection of health care workers (HCW) and patients from COVID-19 infection were implemented, and partly lifted in July 2020. The main exposure for analysis purposes was the period in which patients were operated. Accordingly, study subjects were divided into two groups for subsequent comparisons (preCOVID-19 era: March-June 2018-2019 versus COVID-19 era: March-June 2020). The primary endpoint was the occurrence of superficial and/or deep SSI within 30 days after surgery. The Centers for Disease Control and Prevention definitions were used to classify superficial and deep SSI.

RESULTS

A total of 194 consecutive patients who underwent vascular exposure in the groin were retrospectively analyzed. Of those, 60 underwent surgery from April 1, 2018 to June 30 of the same year; 83 from April 1, 2019 to June 30 of the same year; and 51 from April 1, 2020 to June 30 of the same year. The mean age of the study cohort was 75 years and 140 (72%) were males. Patients who were operated in the COVID-19 era were less likely to develop SSI (10% vs. 28%; P = 0.008), including both deep SSI (4% vs. 13%; P = 0.04) and superficial SSI (6% vs. 15%; P = 0.05). After multivariate adjustments, being operated in the COVID-19 era was found to be a negative predictor for development of an SSI (odds ratio [OR] = 0.31; 95% confidence interval [CI] = 0.09-0.76; P < 0.001) or deep SSI (OR = 0.21; 95% CI = 0.03-0.98; P < 0.001). Operative time was also found as independent predictor for the development of deep SSI (OR = 1.21; 95%CI = 1.21-1.52; P = 0.02). Using binary logistic regression, there were no independent predictors of superficial SSI that could be identified.

CONCLUSIONS

Vascular exposure in the groin carries a non-negligible risk of SSI. In this study, we provided important insights that are simple and easily viable precautions (such as the universal use of surgical masks both for patients and health care professionals during wound care, the widespread diffusion of hand sanitizers, and the reduction of the number of visitors in the surgical wards) could be promising and safe tools for SSI risk reduction.

Ruptured infective native thoracic aortic aneurysm treated by endovascular repair as a bridge therapy to open repair

We report the case of a 70-year-old woman who presented with a ruptured infective native thoracic aortic aneurysm (INTAA), associated with spondylodiscitis and posterior mediastinitis. She underwent a staged hybrid repair: urgent thoracic endovascular aortic repair was first performed as a bridge therapy in the context of septic shock. Allograft repair using cardiopulmonary bypass was performed five days later. Given the complexity of INTAA, multidisciplinary teamwork was paramount to determine the most appropriate treatment strategy, including procedure planning with multiple operators as well as perioperative care. Therapeutic alternatives are discussed.

Outcomes of Candida and Non-Candida Aortic Graft Infection

OBJECTIVE

To evaluate and compare the outcomes of Candida- and non-Candida-associated aortic graft infections.

METHODS

We retrospectively analyzed the data from patients treated for aortic graft infection from 2015 to 2021 in our hospital.

RESULTS

A total of 66 patients (56 men; median age, 69 years; range, 50-87 years) were admitted with aortic graft infection, including 21 (32%) patients in the Candida group and 45 (68%) in the non-Candida group. The average time between initial operation and presentation of aortic graft infection was 50 months (range, 1-332 months). Graft-enteric fistulas (GEFs) were more often in the Candida group (57% vs 27%, P = .017). The most proven causative fungal specimen was C. albicans in 16 (76%) patients. Non-albicans Candida was found in 9% of all patients and 29% of the Candida patients. The median ICU length of stay was longer in the Candida group than non-Candida (10 vs 9 days, P = .012). Additionally, the median hospital length of stay was longer in the Candida group (33 vs 22 days, P = .048). There were no statistically significant differences between Candida and non-Candida groups according to the in-hospital mortality (24% vs 24%, P = .955), and 1-year mortality (38% vs 38%, P = .980).

CONCLUSIONS

Patients with bacterial and fungal aortic graft infections have high rates of morbidity and mortality. We found no significant differences in postoperative morbidity and mortality between Candida and non-Candida patients. However, the ICU and hospital length of stay were longer in the Candida group.

Infection-specific PET imaging with 18F-fluorodeoxysorbitol and 2-[18F]F-ρ-aminobenzoic acid: An extended diagnostic tool for bacterial and fungal diseases

Introduction

Suspected infectious diseases located in difficult-to-access sites can be challenging due to the need for invasive procedures to isolate the etiological agent. Positron emission tomography (PET) is a non-invasive imaging technology that can help locate the infection site. The most widely used radiotracer for PET imaging (2-deoxy-2[¹⁸F] fluoro-D-glucose: [¹⁸F]FDG) shows uptake in both infected and sterile inflammation. Therefore, there is a need to develop new radiotracers able to specifically detect microorganisms.

Methods

We tested two specific radiotracers: 2-deoxy-2-[¹⁸F]-fluoro-D-sorbitol ([¹⁸F]FDS) and 2-[¹⁸F]F-ρ-aminobenzoic acid ([¹⁸F]FPABA), and also developed a simplified alternative of the latter for automated synthesis. Clinical and reference isolates of bacterial and yeast species (19 different strains in all) were tested in vitro and in an experimental mouse model of myositis infection.

Results and discussion

Non-lactose fermenters (Pseudomonas aeruginosa and Stenotrophomonas maltophilia) were unable to take up [¹⁸F]FDG in vitro. [¹⁸F]FDS PET was able to visualize Enterobacterales myositis infection (i.e., Escherichia coli) and to differentiate between yeasts with differential assimilation of sorbitol (i.e., Candida albicans vs. Candida glabrata). All bacteria and yeasts tested were detected in vitro by [¹⁸F]FPABA. Furthermore, [¹⁸F]FPABA was able to distinguish between inflammation and infection in the myositis mouse model (E. coli and Staphylococcus aureus) and could be used as a probe for a wide variety of bacterial and fungal species.

Radiometal chelators for infection diagnostics

Infection of native tissues or implanted devices is common, but clinical diagnosis is frequently difficult and currently available noninvasive tests perform poorly. Immunocompromised individuals (for example transplant recipients, or those with cancer) are at increased risk. No imaging test in clinical use can specifically identify infection, or accurately differentiate bacterial from fungal infections. Commonly used [18F]fluorodeoxyglucose (18FDG) positron emission computed tomography (PET/CT) is sensitive for infection, but limited by poor specificity because increased glucose uptake may also indicate inflammation or malignancy. Furthermore, this tracer provides no indication of the type of infective agent (bacterial, fungal, or parasitic). Imaging tools that directly and specifically target microbial pathogens are highly desirable to improve noninvasive infection diagnosis and localization. A growing field of research is exploring the utility of radiometals and their chelators (siderophores), which are small molecules that bind radiometals and form a stable complex allowing sequestration by microbes. This radiometal-chelator complex can be directed to a specific microbial target in vivo, facilitating anatomical localization by PET or single photon emission computed tomography. Additionally, bifunctional chelators can further conjugate therapeutic molecules (e.g., peptides, antibiotics, antibodies) while still bound to desired radiometals, combining specific imaging with highly targeted antimicrobial therapy. These novel therapeutics may prove a useful complement to the armamentarium in the global fight against antimicrobial resistance. This review will highlight current state of infection imaging diagnostics and their limitations, strategies to develop infection-specific diagnostics, recent advances in radiometal-based chelators for microbial infection imaging, challenges, and future directions to improve targeted diagnostics and/or therapeutics.

Vascular Graft Infection Imaging

Vascular graft infection is a rare, life threatening complication of vascular repair with synthetic or native material. The pathogenesis, causative microorganisms and clinical manifestations vary according to graft's location and time duration since surgery. The diagnosis of graft infection is challenging since there is no single "gold standard" test and diagnosis is based on clinical and radiological criteria. Early and accurate diagnosis are essential for patient management and prevention of further complications. The first-choice imaging modality is computed tomography angiography (CTA) that can demonstrate typical signs of graft infection but has limited sensitivity and specificity, especially in early and low-grade infections. Nuclear medicine imaging methods, including labeled white blood cell scintigraphy and FDG PET/CT demonstrate improved diagnostic accuracy and play a pivotal role in the diagnosis of vascular graft infection. The different radiologic and the nuclear medicine imaging techniques, their advantages and limitations, and the recent guidelines detailing their use are reviewed.

Diagnosis and treatment of vascular graft and endograft infections: a structured clinical approach

A vascular graft or endograft infection (VGEI) is a severe complication that can occur after vascular graft or endograft surgery and is associated with high morbidity and mortality rates. A multidisciplinary approach, consisting of a team of vascular surgeons, infectious diseases specialists, medical microbiologists, radiologists, nuclear medicine specialists, and hospital pharmacists, is needed to adequately diagnose and treat VGEI. A structured diagnostic, antibiotic, and surgical treatment algorithm helps clinical decision making and ultimately aims to improve the clinical outcome of patients with a VGEI.

Referral Centre Experience with Infected Abdominal Aortic Endograft Explantation

OBJECTIVE

The increasing use of endovascular aneurysm repair (EVAR) appears to be associated with the burden of vascular endograft infections. Complete stent graft explantation is recommended but leads to significant mortality. This study aimed to assess the technical challenges, complications, and mortality rate following infected endograft explantation.

METHODS

Patients who underwent abdominal aortic endograft explantation for infection at the Bordeaux University Hospital from July 2008 to December 2020 were included retrospectively in this single centre observational study. The diagnosis was established based on the MAGIC criteria. The primary endpoint was 30 day mortality. Secondary endpoints were 90 day and in hospital mortality, survival, and re-infection.

RESULTS

Thirty-four patients were included, median age 69 years (interquartile range [IQR] 65, 76), with four (12%) treated as an emergency. The median time from EVAR to explantation was 17.5 months (4.5 - 36.3). In situ reconstruction was carried out with prosthetic grafts in 24 patients (71%, including 23 antimicrobial grafts combining silver and triclosan), and biological grafts in 10 (five femoral veins, four arterial allografts, three bovine patches, one biosynthetic graft). Seventeen aorto-enteric fistulae (AEnF) were addressed with direct repair of the intestinal tract (n = 10/17; 59%) or resection and anastomosis (n = 7/17; 41%). The culture was polymicrobial in 12 patients (35%) and remained sterile in four (12%). The 30 day and in hospital mortality rates were 21% (n = 7) and 27% (n = 9). Twenty-five patients (73%) presented with early post-operative complications, requiring 16 revision procedures (47%). Over a median follow up of 16.2 months (IQR 8.3, 33.6), the mortality rate was 35% (n = 12; 11 aortic related; 32%), with two re-infections (6%), both after biological reconstruction (one for an AEnF).

CONCLUSION

Early morbidity and mortality remain high after complete infected endograft explantation, even in a high volume centre. Comparison with other treatment modalities in large multicentre cohorts might be of interest.

Expert opinions in nuclear medicine: Finding the "holy grail" in infection imaging

Nuclear medicine imaging techniques are now widely accepted and increasingly used for diagnosing and treatment monitoring of infectious and inflammatory diseases. The latter has been exemplified by numerous recent clinical guidelines in which PET imaging is now part of the diagnostic flowcharts. In this perspective paper we discuss the current available guidelines, the current limitations, and we provide the future aims of research to achieve the holy grail in nuclear medicine: the differentiation between infection, inflammation and malignancy.

A role of FDG PET/CT for Response Assessment in Large Vessel Disease?

Currently, a large amount of evidence-based data clearly demonstrates the usefulness of [¹⁸F]FDG PET/CT in the diagnosis of several infectious and inflammatory diseases, including those related to the large vessels. The aim of this article is to clarify whether, beyond initial diagnosis, [¹⁸F]FDG PET/CT may have a role in treatment response assessment in inflammatory or infectious diseases of the large vessels, including large vessel vasculitis, vascular graft infection, retroperitoneal fibrosis/chronic periaortitis and infective native aortic aneurysms. Rapidly accumulating data suggest that [¹⁸F]FDG PET/CT could be a valuable imaging method for therapy monitoring in some infectious and inflammatory diseases of large vessels. The available data, albeit preliminary, indicate that [¹⁸F]FDG PET/CT could even play a pivotal role in the management of these diseases, leading to better drug dosage, confirmation of the usefulness of the treatment, and early modification of the therapeutic strategy. However, to date, the role of [¹⁸F]FDG PET/CT for treatment assessment in large vessel diseases, in particular large vessel vasculitis, is not clearly defined and well-designed prospective studies are needed to confirm its possible role in treatment monitoring and treatment guidance.

Multidisciplinary diagnosis and management of inflammatory aortic aneurysms

BACKGROUND

Inflammatory abdominal aortic aneurysms (IAAAs) are a variant involving a distinct immunoinflammatory process, with nearly one half believed to be associated with IgG4-related disease (IgG4-RD).

METHODS

MEDLINE and Google Scholar searches were conducted for English-language publications relevant to inflammatory aortic aneurysms from January 1970 onward. The search terms included inflammatory aortic aneurysms, aortitis, periaortitis, IgG4-related disease, and retroperitoneal fibrosis. Relevant studies were selected for review based on their relevance.

RESULTS

Morphologically, IAAAs are characterized by a thickened aneurysm wall often displaying contrast enhancement and elevated metabolic activity on fluorine-18 fluorodeoxyglucose-positron emission tomography imaging. A strong association exists with perianeurysmal and retroperitoneal fibrosis. Although the rupture risk appears lower with IAAAs than with noninflammatory abdominal aortic aneurysms (AAAs), the currently recommended diameter threshold for operative management is the same. Open repair has been associated with increased morbidity compared with noninflammatory AAAs, and a retroperitoneal approach or minimal dissection transperitoneal approach has been recommended to avoid duodenal and retroperitoneal structural injuries. Endovascular aneurysm repair has been increasingly used, especially for patients unfit for open surgery. It is important to exclude an infectious etiology before the initiation of immunosuppressive therapy or operative repair. Multimodality imaging follow-up is critical to monitor disease activity and secondary involvement of retroperitoneal structures by the associated fibrotic process. Maintenance of immunosuppressive therapy will be needed postoperatively for most patients with active systemic disease, especially those with IgG4-RD and those with persistent symptoms. Additional interventions aimed at ureteral decompression could also be required, and lifelong follow-up is mandatory.

CONCLUSIONS

Preoperative multimodality imaging is a diagnostic cornerstone for assessment of the disease extent and activity. IgG4-RD is an increasingly recognized category of IAAAs, with implications for tailoring adjunctive medical therapy. Open surgical repair remains the procedure of choice, although endovascular aneurysm repair is increasingly being offered. Maintenance immunosuppressive therapy can be offered according to the disease activity as assessed by follow-up imaging studies.

Femur Osteomyelitis and Associated Fracture as an Initial Presentation of Aortoenteric Fistula

Aortoenteric fistula is a rare condition. Atypical presentations may cause significant management delays. We present the case of a 64-year-old male who experienced a pathological femoral fracture as an initial presentation of an underlying aortoenteric fistula. The aortoenteric fistula, possibly related to a poor graft tunneling technique, induced femur osteomyelitis and the associated pathological fracture.

Thoracic aortic vascular graft infection: outcome after conservative treatment without graft removal

OBJECTIVES

Surgical debridement with aortic graft removal is considered the preferred treatment for thoracic aortic vascular graft infection (VGI). Conservative treatment with antibiotics only is usually reserved for inoperable patients. Due to Outpatient Parenteral Antimicrobial Therapy (OPAT) and better understanding of the antibiotic impact on biofilms, long-term targeted antibiotic therapy without graft removal may be an alternative treatment option for selected thoracic aortic VGI patients. The aim of this case series was to evaluate the outcome in patients with thoracic aortic VGI who were treated without graft removal.

METHODS

This single-centre retrospective cohort study evaluated patients with a thoracic aortic VGI diagnosed between 2008 and 2021 and who were treated without graft removal. The primary outcome parameter was the 6-month mortality rate after VGI diagnosis. Secondary outcome parameters were cure rates and relapse of infection.

RESULTS

Twenty-four patients with thoracic aortic VGI who were managed without graft removal were identified. The mortality rate 6 months after VGI diagnosis was 8% (2/24); one of these deaths was infection related. The median antibiotic treatment duration was 13 months (interquartile range 15). A total of 16 patients (67%) were cured. No relapses occurred after a median of 24-month (interquartile range 32) follow-up.

CONCLUSIONS

Intensive antibiotic treatment, without graft removal, may be a non-inferior option in patients with a thoracic aortic VGI who are not considered for surgery.

Ovine Biosynthetic Grafts for Aortoiliac Reconstructions in Nonsterile Operative Fields

BACKGROUND

Prosthetic vascular grafts placed surgically or via endovascular techniques can be subject to the risk of life-threatening graft infections. The Omniflow II vascular prosthesis is a biosynthetic graft that was reported to have favorable properties in resisting infections.

MATERIALS AND METHODS

We retrospectively reviewed our 3 years' experience of using the Omniflow II prostheses for aortoiliac reconstructions in patients considered to carry a substantial risk of subsequent prosthetic graft infections (prevention group) as well as in patients with actively infected prosthetic vascular grafts (treatment group).

RESULTS

Aorto-bi-iliac (n = 4) and aortobifemoral (n = 12) vascular reconstructions were performed using bifurcated Omniflow II prostheses in nine patients in the prevention group and seven patients in the treatment group. During mean follow-up of 28.6 ± 17.2 months, there was one case of graft infection (6.3%) and graft thrombosis (6.3%) with subsequent successful thrombectomy. Early and late surgical revisions were required in eight (50%) and two (12.6%) patients, respectively. All graft prostheses were patent at last follow-up.

CONCLUSION

Using bifurcated Omniflow II vascular prostheses in patients with or at a high risk of vascular graft infection is advisable, and is associated with acceptable reinfection and patency rates.

In situ repair or reconstruction of the abdominal aorta-iliac artery by autologous fascia-peritoneum with posterior rectus sheath for the treatment of the infected abdominal aortic and iliac artery aneurysms: A case series and literature review

Background

Infected abdominal aortic and iliac artery aneurysms are considered acute and severe diseases with insidious onset, rapid development, and high mortality in vascular surgery. Currently, there is no better treatment, either anatomic or extra-anatomical repair.

Case presentation

From February 2018 to April 2022, 7 patients with infected abdominal aortic and iliac artery aneurysms did not have sufficient autologous venous material for repair. With the consent of the Ethics Committee of the hospital, it uses the autologous peritoneal fascial tissue with rectus sheath to repair or reconstruct the infected vessels in situ. There were 5 cases of infected abdominal aortic aneurysm, 1 case of an infected common iliac aneurysm, and 1 case of the infected internal iliac aneurysm. Aortoduodenal fistula was found in 3 cases, all of them were given duodenal fistula repair and gastrojejunostomy and cholecystostomy. Three cases of infected abdominal aortic aneurysms were repaired with the autologous peritoneal fascial tissue patch, and 2 cases of infected abdominal aortic aneurysms were reconstructed by the autologous peritoneal fascial tissue suture to bifurcate graft in situ, the autologous peritoneal fascial tissue suture reconstructed the rest 2 cases of infected iliac aneurysm to tubular graft in situ. It was essential that Careful debridement of all infected tissue and adequate postoperative irrigation and drainage. Antibiotics were administered perioperatively, and all patients were subsequently treated with long-term antibiotics based on bacterial culture and susceptibility results of infected tissues and blood. All 7 patients had underwent surgery successfully. But there were 2 cases died of anastomotic infection or massive hemorrhage after the operation, the other 5 cases survived. The follow-up time was 2–19 months. The enhanced CT of postoperation showed that the reconstructed arteries were smooth without obvious stenosis or expansion, and no abdominal wall hernia occurred.

Conclusion

In situ repair or reconstruction with autologous peritoneal fascial tissue with rectus sheath is a feasible treatment for the infected aneurysm patients without adequate autologous venous substitute, but it still needs long-term follow-up and a large sample to be further confirmed.

Management and Clinical Outcome of Aortic Graft Infections: A Single-Center Retrospective Study

BACKGROUND

This study aimed to evaluate the outcome of various treatment options for aortic graft infection (AGI) patients and identify factors affecting their prognosis.

METHODS

The data of AGI patients from January 2008 to December 2019 were retrospectively collected and analyzed. The primary endpoints were 30-day mortality and perioperative complication-related morbidity; the secondary endpoints were re-infection (RI) rates, primary and secondary graft patency, overall mortality, duration of antibiotic therapy, and the number of antibiotic types used in treatment.

RESULTS

There was no significant difference in the 30-day mortality and perioperative-related complications between the conservative treatment, in-situ reconstruction (ISR), and extra-anatomic reconstruction (EAR) groups. The ISR group had lower re-infection rates and better overall survival rates than the EAR and conservative treatment groups. Different bypass graft conduits had no significant influence on the RI rate or primary and secondary graft patency. AGI patients infected with high-virulence pathogens had higher RI and overall mortality rates than those infected with low virulence pathogens, but this was not statistically significant. Initial procedures prior to the AGI also had no influence on the prognosis of AGI patients. Patients undergoing ISR or EAR surgery received antibiotic therapy for a longer duration than patients undergoing conservative treatment. Patients without RI received more types of antibiotics than patients with RI.

CONCLUSIONS

ISR had lower RI rates and better overall survival rates than EAR and conservative treatment and may be a better choice for patients with AGI. Several factors were found to have no influence on patients' prognosis however, further studies are required.

Treatment Options for Pseudoaneurysm After Carotid Endarterectomy: A Systematic Review and Illustrative Case

BACKGROUND

The goal of this study was to systematically review the management and outcomes of patients who developed pseudoaneurysm (PA) after carotid endarterectomy (postendarterectomy PA [PEPA]).

METHODS

Following the PRISMA guidelines, a systematic literature review was performed using PubMed, Scopus, and Web of Science databases from date of inception to June 2022. Studies were selected based on predetermined inclusion and exclusion criteria. Simultaneously, a retrospective review was conducted of patients who underwent neurosurgical evaluation of suspected PEPA at our institution.

RESULTS

Of the 321 articles in the original literature search, 62 were selected. A total of 143 patients (93 men, 27 women; mean age, 70.7 years) diagnosed with PEPA were included. Mean time from carotid endarterectomy to PA diagnosis was 41.8 months. Primary repair data were available for 135 patients, including 19 with primary closures, 112 with patch or graft repairs, and 4 with eversion procedures. Fifty-five patients with PA (39%) presented with infection. Staphylococcal species were the most common causative organism. Of infected PAs, 89.1% were treated with open procedures. Overall complication rates of PAs treated via open, endovascular, and hybrid methods were 31%, 15.4%, and 0%, respectively. Open ligation (42.9%) and aneurysmectomy with grafting (36.4%) resulted in the highest rates of complications.

CONCLUSIONS

Despite higher complication rates after open repair strategies, use of these techniques remains a viable option in situations requiring removal of infected patches or evacuation of large extravascular collections. Endovascular treatment options are associated with low numbers of complications and can be considered for primary PEPA treatment when infection is not present.

Early and Late Outcomes of Endovascular Aneurysm Repair for Infected Abdominal Aortic and/or Iliac Aneurysms

BACKGROUND

Infected abdominal aortic and/or iliac aneurysm (AAIA) is a rare condition with a high mortality rate when treated with open surgery. In the past decade, the condition has increasingly been treated with endovascular aneurysm repair (EVAR). However, early and late outcomes, including the continued need for antibiotic treatments and predictors of persistent infection, are poorly understood.

METHODS

We evaluated the outcomes of patients who underwent EVAR for infected AAIA from January 2010 to October 2017. We collected data including patient age, gender, clinical presentation, aneurysm location, culture results, intraoperative details, postoperative complications, 30-day mortality, in-hospital mortality, persistent infection, reintervention, and survival.

RESULTS

Among 792 patients diagnosed with AAIA, 64 were diagnosed with primary infected aneurysm, underwent EVAR, and were included in this study (81.3% male; median age, 72 years; range, 18-94 years). The most commonly isolated organisms were Salmonella species (34%), followed by Streptococcus (21%), and Staphylococcus species (21%). Aneurysms were intact in 48 patients (75%) and were ruptured in 16 (25%). The perioperative mortality was 4.7% (3 patients) of whom one was diagnosed with ruptured infected AAIA. Six (9.4%) patients died during hospitalization, 5 of severe sepsis with multiorgan failure and one of myocardial infarction. Among the 58 surviving patients, 34 (58.6%) had persistent infection, of whom 13 (22.4%) required early and late reintervention, including 2 with endograft infection, 8 with primary and secondary aortoenteric fistula, 2 with recurrent new aortic infection, and one with graft limb occlusion. The remaining 24 patients were able to discontinue antibiotics and had no recurrence or need for reintervention. Overall survival rates at 1, 3, and 5 years in the antibiotic-discontinuation group were 91.7%, 87.5%, and 68.0%, respectively, and 82.4%, 52.6%, and 32.9%, respectively, in the persistent-infection group (P = 0.009). In multivariable analysis, primary aortoenteric fistula (Adjusted OR [aOR], 20.469; 95% confidence interval (CI), 1.265-331.320; P = 0.034) and preoperative serum albumin level <3 g/dL (aOR, 7.399; 95% CI, 1.176-46.558; P = 0.033) were preoperative parameter that predicted persistent infection. A C-reactive protein level more than 5 mg/L (aOR, 34.378; 95% CI, 4.888-241.788; P < 0.001) was observed in patients with persistent infection.

CONCLUSIONS

EVAR is a feasible treatment with acceptable perioperative mortality for infected AAIA. Patients able to discontinue antibiotics have better survival and lower reintervention rates than those with persistent infection. A preoperative albumin level below 3 g/dL and primary aortoenteric fistula predicted persistent infection in this population.

Comparison of arterial and venous allograft bypass in chronic limb-threatening ischemia

INTRODUCTION

Femoro-popliteal bypass with autologous vascular graft is a key revascularization method in chronic limb-threatening ischemia (CLTI). However, the lack of suitable autologous conduit may occur in 15-45% of the patients, necessitating the implantation of prosthetic or allogen grafts. Only little data is available on the outcome of allograft use in CLTI.

AIMS

Our objective were to evaluate the long term results of infrainguinal allograft bypass surgery in patients with chronic limb-threatening ischemia (CLTI) and compare the results of arterial and venous allografts.

METHODS

Single center, retrospective study analysing the outcomes of infrainguinal allograft bypass surgery in patients with CLTI between January 2007 and December 2017.

RESULTS

During a 11-year period, 134 infrainguinal allograft bypasses were performed for CLTI [91 males (67.9%)]. Great saphenous vein (GSV) was implanted in 100 cases, superficial femoral artery (SFA) was implanted in 34 cases. Early postoperative complications appeared in 16.4% of cases and perioperative mortality (<30 days) was 1.4%. Primary patency at one, three and five years was 59%, 44% and 41%, respectively, while secondary patency was 60%, 45% and 41%, respectively. Primary patency of the SFA allografts was significantly higher than GSV allografts (1 year: SFA: 84% vs. GSV: 51% p = 0,001; 3 years: SFA: 76% vs. GSV: 32% p = 0,001; 5 years: SFA: 71% vs. GSV: 30% p = 0.001). Both primary and secondary patency of SFA allograft implanted in below-knee position were significantly higher than GSV bypasses (p = 0.0006; p = 0.0005, respectively). Limb salvage at one, three and five years following surgery was 74%, 64% and 62%, respectively. Long-term survival was 53% at 5 years.

CONCLUSION

Allograft implantation is a suitable method for limb salvage in CLTI. The patency of arterial allograft is better than venous allograft patency, especially in below-knee position during infrainguinal allograft bypass surgery.

A New Mini-Invasive Approach for a Catastrophic Disease: Staged Endovascular and Endoscopic Treatment of Aorto-Esophageal Fistulas

Aorto-esophageal fistula (AEF) is an uncommon but usually fatal disorder. Surgery with resection of an aneurysm and esophagus, in situ reconstruction of the descending aorta and omental flap installation offers the gold standard for the reduction of infections, but it is burdened by high intraoperative and perioperative mortality rates. We report our experience with a combined minimally invasive approach for the multi-stage treatment of three cases of aorto-esophageal fistula caused by thoracic aneurysm rupture. In all of the patients, the aneurysm was treated with thoracic endovascular aortic repair and the esophageal lesion was treated with esophageal endoprosthesis placement. According to our experience, the combined strategy of thoracic endovascular aortic repair (TEVAR) and esophageal less invasive endoscopic treatments represents an alternative solution in frail patients with high surgical risk.

The application of modular multifunctional left heart bypass circuit system integrated with ultrafiltration in thoracoabdominal aortic aneurysm repair

Open thoracoabdominal aortic aneurysm (TAAA) repair is a complex and challenging operation with a high incidence of serious complications, and high perioperative mortality and morbidity. Left heart bypass (LHB) is a circulatory support system used to perfuse the distal aorta during TAAA operation, and the advantages of LHB include guaranteeing distal perfusion, reducing the use of heparin, and diminishing the risk of bleeding and postoperative neurological deficits. In China, the circuit for TAAA repair is deficient, and far from the perfusion requirements. We designed a modular multifunctional LHB circuit for TAAA repair. The modular circuit consisted of cannulation pipelines, functional consumables connection pipelines, and accessory pipelines. The accessory pipelines make up lines for selective visceral perfusion and kidney perfusion, suckers and rapid infusion. The circuit can be assembled according to surgical requirements. The ultrafilter and heat exchanger are integrated into the circuit to fulfill the basic demands of LHB. The LHB circuit also has pipelines for selective visceral perfusion to the celiac artery and superior mesenteric artery and renal perfusion pipelines. Meanwhile, the reserved pipelines facilitate the quick switch from LHB to conventional cardiopulmonary bypass (CPB). The reserved pipelines reduce the time of reassembling the CPB circuit. Moreover, the rapid infusion was integrated into the LHB circuit, which can rapid infusion when massive hemorrhage during the open procedures such as exposure and reconstruction of the aorta. The ultrafiltration can diminish the consequent hemodilution of hemorrhage and rapid infusion. A hemoperfusion cartridge also can be added to reduce the systemic inflammatory during operation. The circuit can meet the needs of LHB and quickly switch to conventional CPB. No oxygenator was required during LHB, which reduce the use of heparin and reduce the risk of bleeding. The heat exchanger contributes to temperature regulation; ultrafiltration, arterial filter, and rapid-infusion facilitated the blood volume management and are useful to maintain hemodynamic stability. This circuit made the assembly of the LHB circuit more easily, and more efficient, which may contribute to the TAAA repair operation performed in lower volume centers easily. 26 patients who received TAAA repair under the modular multifunctional LHB from January 2018-March 2022 were analyzed, and we achieved acceptable clinical outcomes. The in-hospital mortality and 30-day postoperative mortality were 15.4%, and the postoperative incidences of paraparesis (4%), stroke (4%), and AKI need hemodialysis (12%) were not particularly high, based on the limited patients sample size in short research period duration.

Establishment of rat allogenic vein replacement model and pathological characteristics of the replaced vessels

Background

With the advancement of vascular anastomosis techniques in recent years, radical surgery for tumors combined with venous vascular resection and reconstruction has been widely used. This study intends to establish two different rat vein replacement models, and further analyze the pathological changes of blood vessels after replacement.

Methods

Brown-Norway (BN) rats were selected as donors and recipients, randomly divided into control group, cuff group (1-week group, 2-week group, and 4-week group), and suture group (1-week group, 2-week group, and 4-week group), with 6 rats in each group. The perioperative conditions, inner diameter, flow velocity and histopathological changes of the replaced vessels at different time points were analyzed.

Results

Both cuff group and suture group can safely establish the rat vein replacement model. From the surgical operation, the operation time and venous cross-clamp time in the cuff group were shorter than those in the suture group (P &lt; 0.05). At 2 and 4 weeks after operation, the diameter of suture group was wider than that of cuff group, and the flow rate was faster (P &lt; 0.05). With prolonged postoperative survival, the wall of the replaced vessels underwent infiltration of CD4+ and CD8+ lymphocytes and high TGF-β1 gene expression. This leads to the proliferation of blood vessels and intimal layer. The results of vascular pathological staining showed that the infiltration degree of CD4+ lymphocytes at 2 weeks after operation and CD8+ lymphocytes at 4 weeks after operation in the suture group was lighter than that in the cuff group (P &lt; 0.05). Meanwhile, TGF-β1 gene content at 4 weeks after operation in suture group was significantly lower than that in cuff group (P &lt; 0.05).

Conclusion

Compared with cuff method, suture method is more suitable for the study of long-term pathological changes after vein replacement in rats. The main pathological changes in the long term after venous replacement in syngeneic background may be vascular fibrosis caused by inflammatory cell infiltration.

A role for artificial intelligence in molecular imaging of infection and inflammation

The detection of occult infections and low-grade inflammation in clinical practice remains challenging and much depending on readers’ expertise. Although molecular imaging, like [¹⁸F]FDG PET or radiolabeled leukocyte scintigraphy, offers quantitative and reproducible whole body data on inflammatory responses its interpretation is limited to visual analysis. This often leads to delayed diagnosis and treatment, as well as untapped areas of potential application. Artificial intelligence (AI) offers innovative approaches to mine the wealth of imaging data and has led to disruptive breakthroughs in other medical domains already. Here, we discuss how AI-based tools can improve the detection sensitivity of molecular imaging in infection and inflammation but also how AI might push the data analysis beyond current application toward predicting outcome and long-term risk assessment.

Clinical utility of technetium-99m-labelled leukocyte scan in diagnosis of vascular infections

INTRODUCTION

The diagnosis of vascular graft infections and infected aneurysms via conventional methods such as computed tomography (CT) and ultrasound (US) can often be challenging. Nuclear medicine imaging techniques can detect infection in these difficult cases. We aim to evaluate the diagnostic value of technetium-99m-labelled leukocyte scans in diagnosing vascular graft infections in our centre.

METHODS

There were 164 patient-scans identified over a 16-year period. The electronic clinical records, laboratory findings and radiology of these patients were reviewed. An adapted case definition of infection was defined using the criteria proposed by the Management of Aortic Graft Infection Collaboration. There were 43 patients identified to have vascular indications and had sufficient information to be divided into infected and non-infected groups. Imaging and reports of the leucocyte scans in these patients were analysed to calculate specificity and sensitivity.

RESULTS

Overall sensitivity of leucocyte scans to detect vascular infection was 78.1% and specificity of 81.8% with a positive likelihood ratio of 4.30 and negative likelihood ratio of 0.27. Two false positives in patients with aortic grafts; one patient possibly had concurrent gastrointestinal infection and continued antibiotic treatment. The other patient had persistent uptake around an endoleak and was treated with lifelong antibiotics for aortic vascular graft infection on the basis of the leucocyte scan; no other clinical or laboratory evidence was found to fulfil the case definition of the vascular graft infection.

CONCLUSION

Technetium-99m-labelled leukocyte scan can be a useful adjuvant test in diagnosing suspected vascular infections in this uncommon presentation.

Small Diameter Cell-Free Tissue-Engineered Vascular Grafts: Biomaterials and Manufacture Techniques to Reach Suitable Mechanical Properties

Vascular grafts (VGs) are medical devices intended to replace the function of a blood vessel. Available VGs in the market present low patency rates for small diameter applications setting the VG failure. This event arises from the inadequate response of the cells interacting with the biomaterial in the context of operative conditions generating chronic inflammation and a lack of regenerative signals where stenosis or aneurysms can occur. Tissue Engineered Vascular grafts (TEVGs) aim to induce the regeneration of the native vessel to overcome these limitations. Besides the biochemical stimuli, the biomaterial and the particular micro and macrostructure of the graft will determine the specific behavior under pulsatile pressure. The TEVG must support blood flow withstanding the exerted pressure, allowing the proper compliance required for the biomechanical stimulation needed for regeneration. Although the international standards outline the specific requirements to evaluate vascular grafts, the challenge remains in choosing the proper biomaterial and manufacturing TEVGs with good quality features to perform satisfactorily. In this review, we aim to recognize the best strategies to reach suitable mechanical properties in cell-free TEVGs according to the reported success of different approaches in clinical trials and pre-clinical trials.

Obturator bypass remains a useful option

OBJECTIVES

The femoral tripod remains technically crucial in vascular surgery, as well for an elective revascularization as for an extensive approach to the arterial tree. The management of septic complications and healing disorders in this area is really challenging. Obturator bypass (OB) represents an alternative sometimes employed in this context, but few recent series were recently published. The objectives of this work were thus to evaluate the results of OB in terms of patency, morbi-mortality, healing evolution and absence of reinfection.

MATERIAL AND METHODS

This was a monocentric retrospective study including all the patients treated by OB, whatever the cause, between January 2010 and December 2020. Primary outcomes were the primary and the secondary patencies. The secondary outcomes were the morbi-mortality, freedom from infection and healing.

RESULTS

During this period, 23 OBs were carried out in 22 patients, with a majority of men (77%) whose median age was 70 years [34 - 87]. The indications were infection in 19 patients (86%), and iterative thrombosis in three patients (14%). The substitute was an arterial allograft in 82% of the cases, and the outflow was the deep femoral artery only in 14% of the cases. The median operative time was 224 min [111-391] and median blood losses were 900 mL [300-3900]. We observed seven systemic (32%), and eight local complications (36%). Healing was obtained in 90% of the cases, and freedom from infection was obtained in 100% of the cases. The median duration of follow-up was 594 days [5 - 2517]. One-year, two-year and three-year primary patency rates were 84%, 78%, and 63%, respectively. One-year, two-year and three-year secondary patencies were 94%, 94%, and 80%, respectively. One-month, one-year, two-year and three-year survival rates were 86%, 73%, 67%, and 53%, respectively.

CONCLUSION

Our study showed that the OB represents a relevant alternative in the event of complex lesions of the femoral tripod, with good patency and healing rates and good infection control. On the other hand, its consequences in terms of morbi-mortality confirm that OB is a major surgery that should be used when a traditional approach is not possible.

Open Thoracoabdominal Aortic Procedures following Endovascular Intervention

Open conversion of thoracoabdominal aortic (TAA) disease after failed attempts of endovascular treatment is increasingly required. The main causes are endoleak, endograft failure, infection, disease progression, or persistent false lumen perfusion in dissected aortas. Mortality and morbidity rates are high, higher than after standard TAA open repair. Therefore, this surgery should be performed only in dedicated centers by experienced teams. Specific perioperative organ protection protocols, as well as surgical techniques, are crucial to guarantee acceptable results.

Aortoduodenal Fistula from Duodenal Stenting for Malignant Gastric Obstruction

Introduction

Aortoduodenal fistula (ADF) is a rare cause of upper gastrointestinal (GI) bleeding and is usually fatal without intervention. A high index of suspicion is required to identify and successfully manage this condition.

Report

Three cases of ADF following duodenal stent insertion for gastric outflow obstruction secondary to metastatic adenocarcinoma are presented. All presented with upper GI bleeding and underwent emergency percutaneous endovascular aortic stent graft repair (EVAR), with temporary aortic balloon occlusion in one case. All were successful in achieving haemostasis. The first case, although initially complicated by acute stent thrombosis of the right iliac limb, was discharged to a rehabilitation facility and survived for two years. The second patient died two days after the procedure from sepsis related complications. The third was discharged home six days post-procedure with a three month follow up.

Conclusion

A high suspicion for ADF in patients with previous duodenal stents is required for prompt diagnosis and management. EVAR may increase short to midterm life expectancy.

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Aortoduodenal fistula following duodenal stent for malignant gastric obstruction

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Cases underwent percutaneous endovascular stent graft repair and achieved haemostasis

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In cases of ADF secondary to duodenal stenting, tube endografting may prolong life.