Differences in local immune cell landscape between Q fever and atherosclerotic abdominal aortic aneurysms identified by multiplex immunohistochemistry.

Background: Chronic Q fever is a zoonosis caused by the bacterium Coxiella burnetii which can manifest as infection of an abdominal aortic aneurysm (AAA). Antibiotic therapy often fails, resulting in severe morbidity and high mortality. Whereas previous studies have focused on inflammatory processes in blood, the aim of this study was to investigate local inflammation in aortic tissue. Methods: Multiplex immunohistochemistry was used to investigate local inflammation in Q fever AAAs compared to atherosclerotic AAAs in aorta tissue specimen. Two six-plex panels were used to study both the innate and adaptive immune systems. Results: Q fever AAAs and atherosclerotic AAAs contained similar numbers of CD68+ macrophages and CD3+ T cells. However, in Q fever AAAs, the number of CD68+CD206+ M2 macrophages was increased, while expression of GM-CSF was decreased compared to atherosclerotic AAAs. Furthermore, Q fever AAAs showed an increase in both the number of CD8+ cytotoxic T cells and CD3+CD8-FoxP3+ regulatory T cells. Finally, Q fever AAAs did not contain any well-defined granulomas. Conclusions: These findings demonstrate that despite the presence of pro-inflammatory effector cells, persistent local infection with C. burnetii is associated with an immune-suppressed microenvironment. Funding: This work was supported by SCAN consortium: European Research Area - CardioVascualar Diseases (ERA-CVD) grant [JTC2017-044] and TTW-NWO open technology grant [STW-14716].

Meta-analysis finds recurrent infection is more common after endovascular than after open repair of infected abdominal aortic aneurysm.

OBJECTIVE: Controversy has continued regarding the use of endovascular aneurysm repair (EVAR) vs open aneurysm repair (OAR) for infected abdominal aortic aneurysms (AAAs). In the present study, we investigated the comparative outcomes of EVAR and OAR for the treatment of infected AAAs. METHODS: We conducted a systematic review and meta-analysis using the MEDLINE and EMBASE databases through May 2021. We included studies that had described both EVAR and OAR for the treatment of infected AAAs. The primary endpoints were the rates of recurrent infection and related rupture and/or death. Perioperative and 1-year mortality and readmissions and reinterventions were also analyzed. RESULTS: Fourteen observational studies describing a total of 1203 patients (EVAR, 359 [29.8%]; OAR, 844 [70.2%]) were eligible for qualitative analysis. The baseline characteristics included diabetes mellitus (33.2%), fever at presentation (71.6%), rupture at diagnosis (26.1%), and positive blood cultures (52.5%). The mean follow-up period ranged from 12 to 40 months. The use of EVAR became more prevalent in recent years (2016-2020, 32.4%) compared with the former period (2010-2015, 13.8%; P < .0001). Fenestrated, branched, or concomitant visceral debranching EVAR was performed in 6.1% of cases. In OAR, surgical debridement was consistently performed, and in situ reconstruction was applied in 82.2% and an omental flap in 51.5%. In nine studies considered for quantitative analysis, the patients' background (EVAR, n = 264; OAR, n = 274) were statistically balanced. The crude rates of recurrent infection and related rupture or death were 13.6% (95% confidence interval [CI], 8.8%-18.5%) and 4.9% (95% CI 1.8%-8.0%), respectively. The pooled analyses depicted significantly higher rates of recurrent infection after EVAR than after OAR (relative risk [RR], 2.42; 95% CI, 1.80-3.27; P < .0001; I2 = 0%). Recurrent infection-related rupture or death (RR, 1.51; 95% CI, 0.70-3.23; P = .29; I2 = 0%), perioperative death (RR, 0.80; 95% CI, 0.39-1.65; P = .55; I2 = 35%), 1-year mortality (hazard ratio, 1.12; 95% CI, 0.97-1.28; P =.13; I2 = 0%), and readmission or reintervention (RR, 1.16; 95% CI, 0.74-1.82; P =.52; I2 = 0%) were not significantly different statistically between the two groups. Funnel plots showed no evidence of publication bias. Sensitivity analyses of leave-one-out meta-analysis confirmed higher rates of recurrent infection after EVAR. CONCLUSIONS: EVAR has become more prevalent as the initial treatment of infected AAAs. Although operative and 1-year survival were similar between OAR and EVAR groups, recurrent infection was more frequent after EVAR. This limitation should be weighed in selecting patients for EVAR in infected AAAs. Postoperative graft and infection surveillance are critical, especially after EVAR.

Custom-made fenestrated stent for mycotic aortic aneurysms: a report of two cases.

BACKGROUND: Mycotic aortic aneurysm is a rare and potentially life-threatening lesion, and endovascular repair has become increasingly accepted for intervention. Fenestrated endografts are available options to treat aneurysms involving visceral arteries. Here, we first report two patients with mycotic aortic aneurysm involving paraviscereal aorta who were successfully treated with custom-made fenestrated endograft. CASE PRESENTATION: Two patients were presented with mycotic aortic aneurysm. Due to their comorbidities and the involvement of the renal arteries, company-manufactured fenestrated stents were designed. Meanwhile, antibiotic therapy was administrated for 2 months before endovascular repair. Patients improved well without complications. CONCLUSIONS: Custom-made fenestrated endovascular stent is an effective and feasible alternative solution to mycotic paravisceral aorta aneurysm.

The Association of Spondylitis and Aortic Aneurysm Disease.

OBJECTIVES: The aim of this study is to assess any relation between spondylitis and aortic aneurysmal disease by reviewing the current literature. METHODS: A systematic search was undertaken using MEDLINE, EMBASE and CENTRAL databases till May 2019, for articles reporting on patients suffering from spondylitis and aortic aneurysm. RESULTS: The most involved aortic segment was infrarenal aorta (56.9%). The lumbar vertebrae were more frequently affected (79.7%). Commonest symptoms were back pain (79.1%), fever (33.7%) and lower limb pain (29.1%). 55.8% of cases were diagnosed using computed tomography. The pathology was attributed to infectious causes in 25.1% of cases. 53.4% of patients were treated only for the aneurysm, 27.9% for both pathologies, while two patients solely for the vertebral disease. Endovascular aneurysm repair was chosen in 12.8% of cases. The 30-day mortality was 8.1% (7/86); mostly from vascular complications. CONCLUSIONS: A synchronous spondylitis and aortic aneurysm may share common etiopathology, when an infectious or inflammatory cause is presented. The lumbar vertebrae are more frequently affected. Low quality data do not allow safe conclusion to suggest the best treatment option.

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

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

Primary Aortoduodenal Fistula: A Case Report and Current Literature Review.

Primary aortoduodenal fistula is a rare, life-threatening pathology that is difficult to diagnose and manage. We present the case of a 64-year-old male with a primary aortoduodenal fistula. Our patient initially underwent an endovascular aneurysm repair at an outside institution before being transferred to our tertiary care center, where he ultimately had definitive management with an extra-anatomic bypass, aortic ligation, duodenal resection with primary anastomosis, and gastrojejunostomy tube placement. His surgical cultures grew Candida albicans, and he was discharged with a 6-week course of intravenous antibiotics with subsequent antibiotic suppression for 1 year. He died 14 months postoperatively from tongue squamous cell carcinoma. We also review the current literature regarding epidemiology, pathology, diagnostics, management, and case reports from 2015 to present. Overall, timely diagnosis and treatment is imperative for reducing mortality from primary aortoduodenal fistula, and although formal consensus is lacking regarding most clinical aspects, an increasing number of case reports has helped describe options for management.

Hybrid operation for infectious thoracic and abdominal aortic aneurysms complicated with Bacillus Calmette-Guérin therapy for bladder cancer: A case report.

RATIONAL: Bacillus Calmette-Guérin (BCG) intravesical instillation therapy is a widely used treatment for bladder cancer; however, an infectious aneurysm has been reported as a rare complication. PATIENT CONCERNS: A 76-year-old man who underwent BCG intravesical instillation therapy for bladder cancer presented with prolonged dull back pain for 3 months. DIAGNOSIS: Computed tomography (CT) revealed both thoracic and abdominal aortic aneurysms (AAAs). Follow-up CT at 4 weeks after the initial examination showed rapid enlargement of both aneurysms and typical findings of inflammation. Therefore, he was diagnosed with an impending rupture of infectious aneurysms. INTERVENTIONS: Although open surgical resection of both aneurysms and vascular reconstruction were ideal, these operations were considered highly invasive for the patient. Therefore, a hybrid operation consisting of simultaneous endovascular repair of the thoracic aneurysm and open surgery of the abdominal lesion was performed. OUTCOMES: BCG "Tokyo-172" strain was identified in the resected sample from the aneurysmal wall, and he continued to receive oral antituberculosis drugs for 6 months. No sign of recurrent infection was observed 1 year after the operation. LESSONS: A hybrid operation might be justified as an alternative to the conventional open surgical procedure, especially for patients with infectious aneurysms caused by weak pathogenic bacteria such as, the BCG mycobacteria.

Mycotic Abdominal Aortic Aneurysms - A Tertiary Centre Experience and Formulation of a Management Protocol.

BACKGROUND: Mycotic abdominal aorta aneurysm (MAAA) is a rare and life-threatening condition. Because of its rarity, there is a lack of adequately powered studies and consensus on its treatment and follow up. This study aimed to review the outcomes following surgical intervention for MAAA in a single tertiary centre and to formulate a management protocol based on available evidence and expert opinion. MATERIALS AND METHODS: Data were collected by retrospective review of case records of all patients who underwent repair of MAAA in a single tertiary referral centre from 2001 to 2018. Demographic, clinical and outcome data were analysed and compared with previously published series in the literature. A management protocol was formulated based on available literature which was then reviewed and modified as per expert opinion from multidisciplinary discussions. RESULTS: Seventeen patients underwent repair of MAAA during the study period including 4 Open repairs, 4 surgeon modified fenestrated endovascular aortic aneurysm repairs (SM FEVAR) and 9 endovascular aortic aneurysm repairs (EVAR). One-year overall survival was 94.1%, 3-year survival was 81.8% and 5-year survival was 75.0%. The infection-free survival at 1, 3, and 5 years was 87.5%, 81.8% and 62.5%, respectively. The overall survival and infection-free survival curves for Open repair, EVAR and SM FEVAR when compared using Log Rank (Mantel-Cox) test and did not show any statistically significant difference. CONCLUSIONS: Management of MAAA with selective use of open or endovascular repair, in combination with appropriate long-term antibiotic therapy, can achieve acceptable outcomes. The proposed protocol can aid as a guiding document for the management of MAAA but needs taking into consideration individual patient variability and local expertise.

Endovascular repair combined with staged drainage for the treatment of infectious aortic aneurysm: a case report.

BACKGROUND: Infectious aortic aneurysm, defined as a focal dilation of an infectious arterial wall, is an uncommon life-threatening disease. Compared with open surgery, endovascular repair yields acceptable clinical outcomes. However, residual tissue infection may increase the risk of secondary intervention. Here, we present a successful case of endovascular repair combined with staged drainage for the treatment of infectious aortic aneurysm. CASE PRESENTATION: A 58-year-old man presented to hospital with a 3-day history of lower back pain radiating to the back associated with fever. The dynamic imaging characteristics revealed rapid progress of infectious abdominal aortic aneurysm with negative blood culture. The patient underwent endovascular repair and salmonella enteritidis was identified through drain culture. CONCLUSIONS: Endovascular procedure and staged drainage can be feasible and effective option in selected cases.

Burkholderia pseudomallei was Identified in a Melioidosis Aneurysm using Polymerase Chain Reaction Targeting 23S rRNA.

Melioidosis abdominal aortic aneurysm and splenic abscesses lead to poor prognosis and high mortality rate as high as 50% due to delayed/missed diagnosis. We describe an attempt to identify Burkholderia pseudomallei immediately, which was confirmed by polymerase chain reaction (PCR) and gene sequence analysis of 23S rRNA gene. PCR is not only an unambiguous identification of B. pseudomallei but also a rapid detection because B. pseudomallei may not be readily isolated. For patients of melioidosis abdominal aortic aneurysm with spleen abscess, prolonged antibiotic therapy, splenectomy and artificial vessel replacement provided an excellent result in our study. The progression, roentgenographic findings and histopathology character of melioidosis are similar to those of tuberculosis disease. PCR is useful to differentiate B. pseudomallei from Mycobacterium tuberculosis.

Mycotic abdominal aortic aneurysm complicated by infective spondylitis due to P seudomonas aeruginosa.

A 67-year-old man with diabetes and hypertension presented with complaints of abdominal pain and lower back ache for 7 months, with intermittent episodes of fever. On examination, there was an expansile mass in the upper abdomen with bruit on auscultation. He also had tenderness in the L1-L2 vertebral space with paraspinal fullness, causing painful restriction of lower limb motor functions but without affecting sensation. On evaluation, he was found to have an abdominal aortic aneurysm with infective lumbar spondylodiscitis. The aspirate from the paravertebral infected tissue and cultures from blood grew Pseudomonas aeruginosa, a rare causative agent of mycotic aortic aneurysm. Whether the infective spondylitis spread to the abdominal aorta causing the mycotic aneurysm or vice versa is a dilemma in such a case. However, the mainstay of treatment remains adequate source control and repair of the aneurysm with appropriate antibiotic therapy. Our patient received intravenous antibiotics for P . aeruginosa based on sensitivity, following which he underwent debridement of the infective spondylodiscitis with aneurysmorrhaphy. He had an uneventful recovery and was well at 3-month follow-up.

Nationwide study of the treatment of mycotic abdominal aortic aneurysms comparing open and endovascular repair in The Netherlands.

OBJECTIVE: Mycotic aneurysms of the abdominal aorta (MAAA) can be treated by open repair (OR) or endovascular aneurysm repair (EVAR). This nationwide study provides an overview of the situation of MAAA treatment in The Netherlands in 2016. METHODS: A retrospective cohort study was conducted with all centers that registered aortic abdominal aneurysms in the Dutch Surgical Aneurysm Audit in 2016. Questionnaires on 1-year outcomes were sent to all centers that treated patients with MAAA. The primary aim was to determine 30-day and 1-year mortality and morbidity of OR- and EVAR-treated patients. Morbidity was determined by the need for reoperations and the number of readmissions to the hospital. RESULTS: Twenty-six MAAA were detected in the Dutch Surgical Aneurysm Audit database of 2016, resulting in an incidence of 0.7% of all registered abdominal aortic aneurysms. The 30-day mortality for OR and EVAR treated patients was 1 in 13 and 0 in 13, respectively. Major and minor reinterventions within 30 days were needed for two (one OR and one EVAR) and two (one OR and one EVAR) patients, respectively. Two patients (15.4%) in the OR group and one patient (7.7%) in the EVAR group were readmitted to hospital within 30 days. In total, 1-year outcomes of 23 patients were available. In the OR group, one patient (9.1%) died in the first postoperative year. There was one major reintervention (removal of endoprosthesis and spiralvein reconstruction) in the EVAR group. Two patients (18.2%) treated with OR and two (16.7%) treated with EVAR required a minor reintervention. In both groups, four patients (OR, 36.4%; EVAR, 33.3%) were readmitted to hospital within 1 year postoperatively. CONCLUSIONS: Both OR- and EVAR-treated patients show acceptable clinical outcomes after 30 days and at the 1-year follow-up. Depending on the clinical course of the patient, EVAR may be considered in the management of this disease.

Alterations in gut microbiota of abdominal aortic aneurysm mice.

BACKGROUND: The gut microbiome plays an important role in various cardiovascular diseases, such as atherosclerosis and hypertension, which are associated with abdominal aortic aneurysms (AAAs). METHODS: Here, we used 16S rRNA sequencing to explore gut microbiota in C57BL ApoE-/- mice with AAAs. A mouse model of abdominal aortic aneurysms was induced with angiotensin II (Ang II) (1000 ng/min per kg). On day 28 after the operation, fecal samples were collected and stored at - 80 °C until DNA extraction. We determined the relative abundances of bacterial taxonomic groups using 16S rRNA amplicon metabarcoding, and sequences were analyzed using a combination of mother software and UPARSE. RESULTS: We found that the gut microbiome was different between control and AAA mice. The results of correlation analysis between AAA diameter and the gut microbiome as well as LEfSe of the genera Akkermansia, Odoribacter, Helicobacter and Ruminococcus might be important in the progression of AAAs. CONCLUSIONS: AAA mice is subjected to gut microbial dysbiosis, and gut microbiota might be a potential target for further investigation.

Tubular Reconstruction with Bovine Pericardium Xenografts to Treat Native Aortic Infections.

BACKGROUND: The treatment of aortic infections is complex, and the material of reconstruction remains discussed. Several alternatives were suggested in the literature. The current consensus is the use of biological material. The aim of this study was to evaluate the short-term results of bovine pericardium xenografts. METHODS: Between November 2016 and June 2019, we included consecutively all the patients presenting with native aortic infections in which arterial reconstruction was carried out with tubular bovine pericardium grafts sutured longitudinally. We collected the preoperative, peroperative, and postoperative clinical, radiological, biological, and bacteriological characteristics. The recurrence of infection, the graft failures, and the morbimortality were analyzed. RESULTS: Twelve patients including three women were treated. Their mean age was 68.4 ± 9 years. They presented 2 thoracic, 4 thoracoabdominal, 4 abdominal, and 2 aortoiliac aneurysms. The diagnosis was made using angio-CT in all the cases and was confirmed by positron emission tomography (PET) scan in 7 cases and blood cultures in 9 cases. Peroperative cultures were positive in 11 cases. Antibiotics were given in 9 patients before operation for a median duration of 9 (3-19) days and in all the patients postoperatively for a median duration of 42 (1-540) days. The median follow-up was 355 (98-839) days. Six medical complications occurred, including 2 (16.6%) leading to death in the immediate postoperative period. No reoperation was needed. The PET scan returned positive in 1/10 cases (10%) during the follow-up. The diameter of the grafts was preserved, without any defect observed on the angio-CT. CONCLUSIONS: Short-term results showed a mechanical resistance to infection of the bovine pericardium. This biological material offers a promising alternative with multiple advantages including availability, simplicity of preparation, and adaptability to the various locations of the aortic infection.

Abdominal Aortic Graft Infection Caused by stG485.0, ST29 Streptococcus dysgalactiae subsp. equisimilis.

In recent years, the prevalence of invasive Streptococcus dysgalactiae subsp. equisimilis (SDSE) infections has increased gradually throughout the world, including Japan. Here, we report the case of an abdominal aortic graft infection caused by stG485.0, ST29 SDSE in an elderly patient with diabetes. The patient was an 86-year-old man who had undergone surgery 10 years ago for treating a non-infected abdominal aortic aneurysm using a bifurcated graft. He was referred to our hospital after being suspected of having an abdominal aortic graft infection based on computed tomography (CT) scans. He underwent surgery to drain the pus that had accumulated between the aneurysm and graft. Although blood cultures were negative, the surgical specimen culture was positive for a ß-hemolytic group G streptococci, which was subsequently identified as SDSE using 16S ribosomal RNA sequencing. Genetic relationships deduced from emm and multilocus sequence typing revealed the isolate to be types stG485.0 and ST29, respectively. Although aortic aneurysm graft infection has a poor prognosis, we successfully rescued the patient through prompt surgery and identification of the responsible pathogen. This case indicates that attention must be paid toward possible SDSE infections in the field of vascular surgery.

Endovascular Aortic Repair Is a Viable Strategy for Treatment of Primary Infected Abdominal Aortic Aneurysm.

BACKGROUND: Infected abdominal aortic aneurysm (IAAA) is rare, and information is limited whether endovascular aortic repair (EVAR) can be considered a permanent treatment or is a temporary fix preceding open surgery. This retrospective study reviewed the short- and long-term outcomes of open surgery, emergent EVAR, and elective EVAR in the treatment of primary IAAA. METHODS: Between January 2008 and January 2017, 16 men and 3 women (aged 60.7 y; range 30-76 y) with IAAA were treated with emergent open repair, emergent EVAR, or elective EVAR, after adjunctive antibiotic therapy. Demographics, aneurysm anatomy, clinical presentations, laboratory tests, details of aneurysm repair, morbidity, mortality, and postoperative outcomes of these patients were reviewed. RESULTS: Positive microbial cultures were obtained in 12 patients. Six and 3 patients underwent emergent EVAR and open repair, respectively. Ten patients who completed the full antibiotic regimen received elective EVAR. The mean follow-up duration was 28.8 mo (range, 1.5-96 mo). The 30-day mortality rates of the emergent EVAR, open repair, and elective EVAR groups were 16.7% (1/6), 0%, and 0%, respectively; the 1-year survival rates were 16.7% (1/6), 100% (1/1), and 88.9% (8/9). Reduction in the blood erythrocyte sedimentation rate (ESR) during the first week of antibiotic treatment was inversely related to aneurysm rupture and correlated with patients' post-EVAR survival time. CONCLUSIONS: Elective EVAR for IAAA had acceptable short- and long-term outcomes. Patients' response to initial antibiotic treatment may help facilitate management. Less than 0.130 reduction in ESR during the first week of antibiotic treatment may indicate risk of aneurysm rupture.

Rare case of a proximal descending thoracic aorta mycotic aneurysm following intravesical BCG injections for the treatment of bladder cancer.

A 79-year-old man presented with an enlarging thoracic aneurysm on the background of superficial bladder cancer treated with intravesical bacillus Calmette-Guérin (BCG) injections. Following the injections, he developed deranged liver function tests and hepatomegaly. Liver biopsy revealed granulomatous hepatitis compatible with disseminated mycobacterial infection (BCG-osis) and was treated with anti-tuberculosis agents for 12 months. A surveillance CT scan performed as a follow-up for his bladder cancer in 2018 revealed a saccular thoracic aneurysm at the ligamentum arteriosum, which was metabolically active on positron emission tomography (PET) scan. Given the timeframe from intravesical instillation of BCG and the metabolic activity on PET scan, the lesion was consistent with a mycotic aneurysm secondary to disseminated mycobacterial infection. Following multidisciplinary team discussion, a thoracic endovascular aneurysm repair was performed. The stent grafts were placed distal to the left subclavian artery with good angiographic results and no immediate postoperative complications. He was initiated on long-term antibiotics to cover potential bacterial pathogens including mycobacterium.

Recommendations for management of infected aortic pathology based on current evidence.

The management of infection involving the abdominal aorta requires clinical decisions based on patient factors and the nature of the infectious process. Any infection occurring after endovascular aortic aneurysm repair or open aortic replacement grafting should be treated promptly with appropriate systemic antibiotic therapy. Once a vascular prosthesis becomes infected, surgical treatment is necessary. There should be a low threshold for graft excision and extra-anatomic bypass in the presence of fistula or abscess cavity, when feasible entire graft should be excised. In selected patients, graft excision with in situ aorta reconstruction is an appropriate option using an autogenous femoral vein, cryopreserved allograft, or a prosthetic graft impregnated with antibiotic. The replaced in situ aortic graft should be covered with an omental pedicle. For primary aortic graft infections, endovascular treatment may act as a bridge to more definitive treatment; or, in the absence of gross retroperitoneal infections, endovascular grafting alone with prolonged systemic antibiotic therapy is a viable option, particularly in patients not fit for open surgical procedures.