Inflammatory Abdominal Aortic Aneurysms

Extravertebral low back pain: a scoping review

BACKGROUND

Low back pain (LBP) is one of the most common reasons for consultation in general practice. Currently, LBP is categorised into specific and non-specific causes. However, extravertebral causes, such as abdominal aortic aneurysm or pancreatitis, are not being considered.

METHODS

A systematic literature search was performed across MEDLINE, Embase, and the Cochrane library, complemented by a handsearch. Studies conducted between 1 January 2001 and 31 December 2020, where LBP was the main symptom, were included.

RESULTS

The literature search identified 6040 studies, from which duplicates were removed, leaving 4105 studies for title and abstract screening. Subsequently, 265 publications were selected for inclusion, with an additional 197 publications identified through the handsearch. The majority of the studies were case reports and case series, predominantly originating from specialised care settings. A clear distinction between vertebral or rare causes of LBP was not always possible. A range of diseases were identified as potential extravertebral causes of LBP, encompassing gynaecological, urological, vascular, systemic, and gastrointestinal diseases. Notably, guidelines exhibited inconsistencies in addressing extravertebral causes.

DISCUSSION

Prior to this review, there has been no systematic investigation into extravertebral causes of LBP. Although these causes are rare, the absence of robust and reliable epidemiological data hinders a comprehensive understanding, as well as the lack of standardised protocols, which contributes to a lack of accurate description of indicative symptoms. While there are certain disease-specific characteristics, such as non-mechanical or cyclical LBP, and atypical accompanying symptoms like fever, abdominal pain, or leg swelling, that may suggest extravertebral causes, it is important to recognise that these features are not universally present in every patient.

CONCLUSION

The differential diagnosis of extravertebral LBP is extensive with relatively low prevalence rates dependent on the clinical setting. Clinicians should maintain a high index of suspicion for extravertebral aetiologies, especially in patients presenting with atypical accompanying symptoms.

Rare case of inflammatory abdominal aortic aneurysm with an aortocaval fistula

Inflammatory abdominal aortic aneurysms (IAAA) are a distinct subcategory of abdominal aortic aneurysms that make up roughly 5%-10% of all abdominal aortic aneurysm (AAA) cases. Inflammatory AAA (IAAA) is distinguished from traditional atherosclerotic AAA by the triad of thickened aneurysm wall, extensive perianeurysmal/retroperitoneal fibrosis, and dense adhesions of adjacent abdominal organs. The purpose of this report is to examine the clinical course of a rare case of inflammatory abdominal aortic aneurysm with aortocaval fistula.

Coexistence of FDG-Avid and FDG-Negative Aneurysms in a Patient With Fever of Unknown Origin

ABSTRACT

A 68-year-old man with intermittent fever of unknown origin for 5 months underwent 18F-FDG PET/CT to detect causative lesion. An 18F-FDG-avid lesion was revealed in the left pelvic iliac vessel region and was highly suggestive of malignancy. One and a half months later, a giant left internal iliac artery aneurysm was identified by CT angiography, corresponding to the 18F-FDG-avid lesion. Combined with elevated inflammatory markers, he was finally diagnosed as having inflammatory internal iliac artery aneurysm. An abdominal aortic aneurysm with low 18F-FDG uptake was also identified.

Ultrasound for the Detection of Inflammatory Abdominal Aortic Aneurysms: A Case and Validation Series

Inflammatory abdominal aortic aneurysms (iAAA) are a form of noninfectious aortitis in patients with abdominal aortic aneurysms (AAA). Ultrasound could help to detect iAAA early. This retrospective observational study assessed the potential of using ultrasound to detect iAAA in a case series of iAAA patients, and the diagnostic value of ultrasound to detect iAAA in consecutive patients in a follow-up for AAA, referred to as a feasibility study. In both studies, diagnosis of iAAA was based on a cuff surrounding the aneurysm using CT (golden standard). The case series included 13 patients (age 64 (61; 72) years; 100% male). The feasibility study included 157 patients (age 75 (67; 80) years; 84% male). In the case series, all iAAA patients showed a cuff surrounding the aortic wall on ultrasound. In the feasibility study with AAA patients, ultrasound yielded no cuff in 147 (93.6%; CT negative in all cases), a typic cuff in 8 (5.1%; CT positive in all cases), and an inconclusive cuff in 2 (1.3%; CT negative in both cases) patients. Sensitivity and specificity were 100% and 98.7%, respectively. This study indicates that iAAA can be identified with ultrasound, and safely ruled out. In positive ultrasound cases, additional CT imaging might still be warranted.

Expert perspectives on pathological findings in vasculitis

Pathological findings are important in the diagnosis of vasculitis. However, due to the rarity of the disease, standard textbooks usually devote only a few pages to this topic, and this makes it difficult for clinicians not specializing in vasculitis to fully understand the pathological findings in vasculitis. To address the paucity of information, we present representative pathological findings in vasculitis classified in the 2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides (CHCC2012). The CHCC2012 classifies 26 vasculitides into seven categories: (1) large-vessel vasculitis, (2) medium-vessel vasculitis, (3) small-vessel vasculitis, including antineutrophil cytoplasmic antibody-associated vasculitis and immune complex small-vessel vasculitis, (4) variable-vessel vasculitis, (5) single-organ vasculitis, (6) vasculitis associated with systemic disease, and (7) vasculitis associated with probable aetiology. Moreover, representative pathological findings of vasculitis-related diseases and non-inflammatory vasculopathy not mentioned in the CHCC2012 are also presented. This will be useful for clinicians to refer to typical pathological findings of vasculitis in daily practice.

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.

CtBP proteins transactivate matrix metalloproteinases and proinflammatory cytokines to mediate the pathogenesis of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a life-threatening disorder that occurs in the aorta. The inflammatory thickness of the aneurysm wall and perianeurysmal fibrosis are two main causes of AAA pathogenesis; however, the molecular mechanisms involved in these two processes are still unclear. We discovered that C-terminal binding protein 1 (CtBP1) and CtBP2 were overexpressed in the aortas of AAA-model mice created by treatment with CaCl₂ and elastase. Molecular analyses revealed that the CtBP heterodimer couples with histone acetyltransferase p300 and transcription factor AP1 (activator protein 1) to transactivate a set of matrix metalloproteinases (MMPs, including MMP1a, 3, 7, 9, and 12) and proinflammatory cytokines, including interleukin-1 β (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α). Knockdown of CtBPs or AP1 subunits or blockage of CtBPs with specific small molecule inhibitors significantly suppressed the in vitro expression of MMPs and proinflammatory cytokines. The administration of CtBP inhibitors in AAA-model mice also inhibited MMPs and proinflammatory cytokines, thereby improving the AAA outcome. Taken together, our results revealed a new regulatory mechanism involving MMPs and proinflammatory cytokines in the pathogenesis of AAA. This discovery suggests that targeting CtBPs may be a therapeutic strategy for AAA by attenuating the inflammatory response and matrix destruction.

Urgent Repair of a 17.3 cm Inflammatory Abdominal Aortic Aneurysm

We describe a case of delayed presentation of a very large infra-renal inflammatory abdominal aortic aneurysm. This case highlights the importance of early detection and surveillance of aneurysms in rural communities. Definitive management of symptomatic aneurysms is time critical, and any delay such as for the transfer of patients from a rural site can impact patient survival. We present an example of a rare variant of abdominal aortic aneurysm.

Clinical Outcomes of Atypical Inflammatory Variants of Abdominal Aortic Aneurysm

Background

Most abdominal aortic aneurysms are degenerative atherosclerotic aneurysms. Inflammatory or infected abdominal aortic aneurysms, which show a slightly different clinical course, are rarely encountered in clinical settings. Therefore, we aimed to investigate the clinical course of these variants of abdominal aortic aneurysms.

Methods

This retrospective study included 32 patients with atypical inflammatory or infected abdominal aortic aneurysms who underwent emergent graft replacement between November 1997 and December 2017. Patients were followed up at the outpatient clinic for a mean period of 4.9±6.9 years. We analyzed the patients' clinical course and compared it with that of patients with atherosclerotic abdominal aortic aneurysms.

Results

There was 1 surgical mortality (3.0%) in a case complicated by aneurysmal free rupture. In 2 cases of infected abdominal aortic aneurysms, anastomotic complications developed immediately postoperatively. During the follow-up period, 10 patients (30%) developed graft complications, and 9 of them underwent reoperations; of these, 2 patients (22.2%) died of postoperative complications after the second operation, whereas 2 patients survived despite graft occlusion.

Conclusion

Patients with inflammatory abdominal aneurysms frequently develop postoperative graft complications requiring secondary surgical treatment, so they require close mandatory postoperative follow-up.

Predictors of Operative Mortality of 928 Intact Aortoiliac Aneurysms

BACKGROUND

The aim of this study is to identify preoperative and intraoperative factors associated with in-hospital mortality of intact abdominal aortoiliac aneurysm repair.

METHODS

In this observational study, prospectively collected information included demographics, risk factors, comorbidities, aneurysm characteristics (including special aneurysm presentation, i.e., inflammatory, mycotic/infected, aortocaval fistula), investigations, and operative variables. Receiver operating characteristic) curve analysis of the Glasgow aneurysm score (GAS) and the Vascular Study Group of New England (VSGNE) score was performed in the subgroup of bland aneurysms undergoing isolated elective repair.

RESULTS

A total of 928 cases with intact aortoiliac aneurysms had an elective (n = 882) or urgent (n = 46) repair, associated with an in-hospital mortality of 1.7% and 8.7%, respectively (P = 0.01). Open repair (n = 514) was a predictor of higher mortality (3.3% vs. 0.5% for endovascular aneurysm repair [EVAR], n = 414, odds ratio [OR] 7.1, P = 0.003), and so was the pre-EVAR era (4.8% vs. 1.3% in the EVAR era, OR 4.0, P = 0.004). Other significant predictors included the presence of abdominal/back pain (7.5% vs. 1.3%, OR = 6.0, P = 0.001), preoperative angiography (7% vs. 1.6%, OR = 4.5, P = 0.01), special aneurysm presentation (10.9% vs. 1.5%, OR = 8.1, P < 0.001), concomitant major procedures (19% vs. 1.7%, OR = 14.0, P < 0.001), serious intraoperative complications (9.1% vs. 1.5%, OR = 6.6, P = 0.001), median number of transfused units of blood intraoperatively (2 and 0 for cases with and without mortality, respectively, P < 0.001), and procedure duration (270 and 150 min for cases with and without mortality, respectively, P < 0.001). Open repair (OR = 4.5, P = 0.05), special aneurysm presentation (OR = 6.58, P = 0.001), and concomitant major procedures (OR = 14.3, P < 0.001) were independent predictors of higher mortality. ROC curve analysis for the GAS (P = 0.87) and VSGNE score (P = 0.10) failed to demonstrate statistical significance in the subgroup of bland aneurysms undergoing isolated elective repair.

CONCLUSIONS

Our study has demonstrated independent risk factors for mortality, which should be considered when contemplating aortoiliac aneurysm repair. We failed to externally validate the GAS and VSGNE score.

Etiology, Diagnosis and Management of Aortitis

Aortitis includes conditions with infectious or non-infectious etiology, characterized by inflammatory changes in one or more layers in aortic wall. Age at onset, geographic predilections, distribution and pattern of involvement in aorta, its branches and pulmonary arteries, and systemic associations provide a clue to etiology. Clinical presentations are often non-specific. An integrated approach including clinical, laboratory and imaging assessment is essential to confirm diagnosis and plan treatment. Assessment of disease activity is the key as it influences timing and outcome of treatment. Markers of activity include clinical, laboratory and imaging. Medical management remains the first-line therapy. Revascularization is indicated in the presence of hemodynamically significant stenosis and inactive disease. In the presence of flash pulmonary edema, left ventricular dysfunction or hypertensive encephalopathy, revascularization is performed irrespective of disease activity. Endovascular management is favored over surgery due to its high success and low restenosis rates. Symptomatic aneurysmal disease is usually managed by surgery.

CCR2 Positron Emission Tomography for the Assessment of Abdominal Aortic Aneurysm Inflammation and Rupture Prediction

BACKGROUND

The monocyte chemoattractant protein-1/CCR2 (chemokine receptor 2) axis plays an important role in abdominal aortic aneurysm (AAA) pathogenesis, with effects on disease progression and anatomic stability. We assessed the expression of CCR2 in a rodent model and human tissues, using a targeted positron emission tomography radiotracer (⁶⁴Cu-DOTA-ECL1i).

METHODS

AAAs were generated in Sprague-Dawley rats by exposing the infrarenal, intraluminal aorta to PPE (porcine pancreatic elastase) under pressure to induce aneurysmal degeneration. Heat-inactivated PPE was used to generate a sham operative control. Rat AAA rupture was stimulated by the administration of β-aminopropionitrile, a lysyl oxidase inhibitor. Biodistribution was performed in wild-type rats at 1 hour post tail vein injection of ⁶⁴Cu-DOTA-ECL1i. Dynamic positron emission tomography/computed tomography imaging was performed in rats to determine the in vivo distribution of radiotracer.

RESULTS

Biodistribution showed fast renal clearance. The localization of radiotracer uptake in AAA was verified with high-resolution computed tomography. At day 7 post-AAA induction, the radiotracer uptake (standardized uptake value [SUV]=0.91±0.25) was approximately twice that of sham-controls (SUV=0.47±0.10; P<0.01). At 14 days post-AAA induction, radiotracer uptake by either group did not significantly change (AAA SUV=0.86±0.17 and sham-control SUV=0.46±0.10), independent of variations in aortic diameter. Competitive CCR2 receptor blocking significantly decreased AAA uptake (SUV=0.42±0.09). Tracer uptake in AAAs that subsequently ruptured (SUV=1.31±0.14; P<0.005) demonstrated uptake nearly twice that of nonruptured AAAs (SUV=0.73±0.11). Histopathologic characterization of rat and human AAA tissues obtained from surgery revealed increased expression of CCR2 that was co-localized with CD68⁺ macrophages. Ex vivo autoradiography demonstrated specific binding of ⁶⁴Cu-DOTA-ECL1i to CCR2 in both rat and human aortic tissues.

CONCLUSIONS

CCR2 positron emission tomography is a promising new biomarker for the noninvasive assessment of AAA inflammation that may aid in associated rupture prediction.

Aortoenteric fistula secondary to an Inflammatory Abdominal Aortic Aneurysm

Primary aortoenteric fistulas are rare, with the annual incidence of such fistulas estimated to be 0.007 per million. The most common predisposing conditions for primary aortoenteric fistulas are atherosclerotic abdominal aortic aneurysms or penetrating atherosclerotic ulcers. We illustrate a rare case of an inflammatory aortic aneurysm causing a primary aortic fistula, with a direct fistulous jet from the aorta to the bowel with resultant catastrophic bleeding. In contrast to atherosclerotic aneurysms, most inflammatory aneurysms are symptomatic and show dense perianeurysmal fibrosis and periaortic wall thickening. A direct jet of contrast extravasation from the aorta into a bowel loop, while rarely seen, remains the most specific sign of a primary aorta-enteric fistula. A comprehensive literature review of the clinical presentation, imaging features, and differential diagnosis of a primary aortoenteric fistula are also discussed.

Outcomes of open and endovascular repair of inflammatory abdominal aortic aneurysms

Objective Reports on inflammatory aortic abdominal aneurysm treatment are scarce. Traditionally, open surgery has been validated as the gold standard of treatment; however, high technical skills are required. Endovascular aortic repair has been suggested as a less invasive treatment by some authors offering good results. The purpose of our study was to report our experience and outcomes in the treatment of inflammatory aortic abdominal aneurysm using both approaches. Material and methods A retrospective review and data collection of all patients treated for inflammatory aortic abdominal aneurysm between 2000 and 2015 was done in one academic center. Diagnosis of inflammatory aortic abdominal aneurysm was based on preoperative CT-scan imaging. Type of treatment, postoperative and long-term morbidity and mortality are described. Abdominal compressive symptoms (hydronephrosis) severity and relief after treatment are described. Results Thirty-four patients with intact inflammatory aortic abdominal aneurysm were included. Twenty-nine (85.3%) patients were treated by open means and the remaining five (14.7%) with endovascular aortic repair. Nearly 90% were considered high-risk patients. Median follow-up was 46 months (range 24-112). The two groups were comparable, except for the age and preoperative hydronephrosis. There was no statistical significance in blood transfusion requirements, intensive care hospitalization, 30-day and long-term mortality between the two groups. Preoperative hydronephrosis was diagnosed in four (13.8%) patients in the open surgery group and three (60%) patients in the endovascular aortic repair group. Improvement of hydronephrosis was recognized in three out of the four patients in the open repair group and two out of the three in the endovascular aortic repair group. Renal function remained stable in both groups during follow-up. Conclusions Open surgery remains a safe and valid option for the treatment of inflammatory aortic abdominal aneurysm. Although our study included a small number of patients with endovascular aortic repair treatment, results are promising. Further randomized controlled studies may be necessary to assess long-term effectiveness of endovascular aortic repair treatment in this disease.

A Benign but Unusual Radiological Sign During EVAS Follow-up

PURPOSE

To report a heretofore undescribed complication seen on imaging after endovascular aortic sealing (EVAS).

CASE REPORT

A 77-year-old woman was treated with the Nellix EVAS device for an infrarenal aortic aneurysm. After a normal computed tomography (CT) scan at 15 days, the 6-month CT showed the onset of perianeurysmal inflammatory tissue. The patient was asymptomatic, and blood tests were normal. Imaging suggested a nonaggressive inflammatory process, so a conservative approach was adopted with close follow-up. The periaortic tissue remitted without any treatment after a further 9 months (16 months after EVAS).

CONCLUSION

The cause of this nonacute complication is unclear. Some clues suggest that interaction between the endobags and aneurysm wall could be involved. Imaging and clinical data led to a successful conservative strategy.

Abdominal Aortic Aneurysm-Associated MicroRNA-516a-5p Regulates Expressions of Methylenetetrahydrofolate Reductase, Matrix Metalloproteinase-2, and Tissue Inhibitor of Matrix Metalloproteinase-1 in Human Abdominal Aortic Vascular Smooth Muscle Cells

BACKGROUND

MicroRNAs (miRNAs or miRs) have been highlighted to be involved in abdominal aortic aneurysm (AAA) with the emergence of recent miRNA microarray profiling studies. miR-516a-5p has been shown to be significantly overexpressed in vascular smooth muscle cells (VSMCs) from human AAA tissues from our previous microarray study, suggesting its crucial association with AAA. In addition, further bioinformatics analysis predicted methylenetetrahydrofolate reductase (MTHFR), which regulates homocysteine (Hcy) metabolism and is proposed to be a risk gene for AAA formation and to be the downregulation target of miR-516a-5p. However, the pathogenic role of miR-516a-5p in VSMCs for AAA formation remains unresolved. This study aims to investigate the role of miR-516a-5p in human VSMCs for AAA pathogenesis.

METHODS

miR-516a-5p was stably overexpressed and knocked down in VSMCs explant cultured from human abdominal aortic tissues by means of lentiviral system. The MTHFR protein expression was first examined by Western blotting. In addition, the protein expressions of several key components involved in AAA pathogenic features are as follows: matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP)-1 and TIMP-2 for elastin degradation; collagen type 1 alpha 1 for compensatory collagen synthesis; monocyte chemoattractant protein-1 for inflammation, were also evaluated. Apoptotic level of VSMCs was examined by terminal deoxynucleotidyl transferase dUTP nick end labeling assay.

RESULTS

Results showed that protein expression of MTHFR was significantly downregulated on miR-516a-5p overexpression (P < 0.05) in VSMCs, whereas it was significantly upregulated on miR-516a-5p knockdown (P < 0.05). Of all the AAA key components investigated, only MMP-2 and TIMP-1 protein expressions were found altered. A significant increase in MMP-2 (P < 0.05) and decrease in TIMP-1 (P < 0.05) expressions were observed on miR-516a-5p overexpression in VSMCs. Apoptosis was not promoted on miR-516a-5p overexpression or knockdown in VSMCs.

CONCLUSIONS

Our findings suggested that miR-516a-5p may regulate MTHFR, MMP-2, and TIMP-1 expressions in human VSMCs, possibly promoting the disruption of Hcy metabolism and proteolytic degradation of elastin for AAA formation.

Inflammatory aortic aneurysm in a young patient with ankylosing spondylitis

Inflammatory conditions are a rare cause of aortic aneurysms, accounting for 3% to 10% of cases. Patients with ankylosing spondylitis uncommonly present with ascending aortic aneurysms related to long-standing, aggressive disease. We review the case of a young man with ankylosing spondylitis exhibiting complex inflammatory aortic aneurysms atypically involving the abdominal and descending thoracic aorta, as well as ectasia of medium-sized visceral vessels. Inflammatory aneurysms require a multidisciplinary approach incorporating diagnostic modalities to confirm etiology, targeted immunosuppressive therapy to control disease activity, and aneurysm repair. Evidence suggests that endovascular approaches should be considered first-line therapy for patients requiring reconstruction when anatomy is appropriate.

Isolated idiopathic aortitis with an unusually thickened aortic wall: case report

Aortitis includes a broad range of disorders involving inflammation of the aorta. While most forms of aortitis can be linked to a specific cause, patients with idiopathic aortitis (IDA), are asymptomatic and usually diagnosed after surgical removal. The specific pathophysiology is not well understood, but can be strongly associated with tobacco smoking, young age at presentation, and family history of aortic aneurysm. Wall thickening is the most common physical characteristic of aortitis, and the inflammation can affect any layer of the aorta. The normal wall thickness of the aorta is less than 4 mm and can be as thick as 9 mm. Few studies document a correlation between wall thickness and the severity of aortitis. This paper presents a unique case of severe aortic aneurysm associated with an abnormal thickening of the ascending aorta.

Long-term Outcome Of Operated Inflammatory Aortic Aneurysms

Inflammatory aortic aneurysms (IAAs) represent a rare form of aortic aneurysms. Compared with atherosclerotic aneurysms, patients with IAA have an increased risk of perioperative and long-term morbidity. This retrospective clinical study analyzed the outcome after conventional and endovascular repair of IAAs.

Patients treated for an abdominal IAA between January 1995 and November 2004 were included. Imaging (computed tomographic angiography or magnetic resonance angiography) was performed preoperatively and at the time of follow-up (mean 2.7 years). Transperitoneal open repair and endovascular aortic repair were the operative procedures used.

Over 10 years, 40 patients were treated with conventional and 5 patients with endovascular repair. The in-hospital morbidity rate was 11.1% (five patients; four conventional, one endovascular). On 10 patients (47.6%), the retroperitoneal fibrosis was no longer detectable.

After operative repair, the majority of cases presented with a distinct regression of inflammation. Endovascular treatment of IAA represents a feasible alternative procedure to open aortic repair.

Inflammatory diseases of the aorta: Part 1: Non-infectious aortitis

Aortitis is a term which encompasses inflammatory changes to the aortic wall from various pathogenic etiologies. Large vessel vasculitis, such as Takayasu arteritis and giant cell arteritis represent the most common entities; however, there is also an association with other rheumatological diseases. Chronic idiopathic periaortitis represents a distinct disease entity and infectious aortitis is a rare but life-threatening disease. Due to the diverse clinical pictures vascular surgeons often face a significant challenge in terms of making an accurate initial diagnosis. Treatment requires an interdisciplinary approach. This article describes the pathogenesis of the various forms of aortitis as well as the diagnostic methods and treatment approaches.

The Acute Abdominal Aorta

Acute disorders of the abdominal aorta are potentially lethal conditions that require prompt evaluation and treatment. Computed tomography (CT) is the primary imaging method for evaluating these conditions because of its availability and speed. Volumetric CT acquisition with multiplanar reconstruction and three-dimensional analysis is now the standard technique for evaluating the aorta. MR imaging may be useful for select applications in stable patients in whom rupture has been excluded. Imaging is indispensable for diagnosis and treatment planning, because management has shifted toward endoluminal repair. Acute abdominal aortic conditions most commonly are complications of aneurysms and atherosclerosis.

Unstable abdominal aortic aneurysms: a review of MDCT imaging features

Abdominal aortic aneurysms are commonly encountered during abdominal CT imaging, and size-based parameters for surgical or endovascular repair are well established. Aneurysms greater than 5 cm in diameter are recognized as representing an increased rupture risk and meriting intervention. Increasingly, additional interest has been generated in recognizing imaging features which may herald instability and portend a higher chance for potentially catastrophic rupture. This article will review and illustrate such signs, including hyperattenuation of mural thrombus, rapid expansion, low thrombus to lumen ratio, intimal calcification disruption, posterior mural draping, and saccular outpouching. Other features of complicated abdominal aneurysms including perianeurysmal inflammation, aortocaval and aortoenteric fistula formation will also be addressed. Heightened awareness of these features and their prognostic implications, as well as timely communication with the clinical service, is critical for the interpreting radiologist.

Open Versus Endovascular Repair of Inflammatory Abdominal Aortic Aneurysms

Objectives:

Open surgical repair (OSR) of inflammatory abdominal aortic aneurysms (IAAAs) can have significant morbidity. The aim of the present investigation was to compare IAAA outcome after OSR and endovascular aneurysm repair (EVAR) and perform a meta-analysis of the literature.

Methods:

Twenty-seven patients with an intact IAAA operated on during a 21-year period were included.

Results:

Nine patients were managed with EVAR and 18 with OSR. In the EVAR group, the number of transfused red blood cell units ( P = .001), procedure duration ( P < .001), and postoperative hospitalization ( P = .004) were significantly reduced compared to OSR. A trend for decreased morbidity with EVAR (11% vs 33% for OSR, P = .36) was observed. On literature review and meta-analysis, morbidity after EVAR was 8.3%, significantly lower compared to OSR (27.4%, P = .047). Mortality for nonruptured IAAAs was 0% after EVAR and 3.6% after OSR ( P = 1.00).

Conclusions:

Endovascular aneurysm repair of IAAAs is associated with decreased procedure duration, transfusion needs, hospitalization, and morbidity compared to OSR.

Endovascular repair versus open repair for inflammatory abdominal aortic aneurysms

BACKGROUND

Inflammatory abdominal aortic aneurysm (IAAA) is a rare but potentially life-threatening condition characterised by marked thickening of the aortic wall, peri-aneurysmal and retroperitoneal fibrosis, and dense adhesions of adjacent abdominal organs. The pathogenesis of IAAA remains an enigma. The main aim of invasive or surgical therapy of AAAs is prevention or correction of aortic rupture. Prevention or treatment of AAA rupture by open or endovascular repair is proven by numerous studies published in the literature. Treatment of IAAA poses a different challenge to surgeons compared with traditional atherosclerotic AAA because of the potential for iatrogenic injury in open repair or, alternatively, potential increased inflammatory response to endoprosthesis implantation.

OBJECTIVES

To assess the effects of elective endovascular versus open repair for inflammatory abdominal aortic aneurysms.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (April 2015) and the Cochrane Register of Studies (CRS) (2015, Issue 3). The TSC searched trial databases for details of ongoing and unpublished studies.

SELECTION CRITERIA

We sought all published and unpublished randomised controlled trials (RCTs), quasi-RCTs and controlled clinical trials comparing results of elective endovascular or open repair of IAAAs without language restriction.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed studies identified for potential inclusion in the review. We planned to conduct data collection and analysis in accordance with the Cochrane Handbook for Systematic Review of Interventions.

MAIN RESULTS

We identified no studies that met the inclusion criteria.

AUTHORS' CONCLUSIONS

We found no published RCTs, quasi RCTs or controlled clinical trials comparing open repair and elective endovascular repair for IAAA, assessing immediate (30-day), intermediate (up to one-year follow-up) and long-term (more than one-year follow-up) mortality or complications rates. High-quality studies evaluating the best treatment for inflammatory abdominal aneurysm repair are required.

Idiopathic and secondary forms of retroperitoneal fibrosis: a diagnostic approach

Retroperitoneal fibrosis (RPF) is an uncommon disease characterized by a fibrous reaction that takes place in the peri-aortic retroperitoneum and often entraps the ureters causing obstructive uropathy. RPF is idiopathic in the majority of cases, but can also be secondary to malignancies, infections, drugs, radiotherapy, and rare histiocytic disorders such as Erdheim-Chester disease. Idiopathic RPF is an immune-mediated disease, which can either be isolated, associated with other autoimmune diseases, or arise in the context of a multifocal fibro-inflammatory disorder recently renamed as IgG4-related disease. The differential diagnosis between idiopathic, IgG4-related and secondary RPF is crucial, essentially because the therapeutic approaches - especially of idiopathic vs. secondary RPF - can be dramatically different. This review focuses on the clinical, laboratory and imaging features of the different RPF forms, and also provides an overview of the available treatment options.

[Rare aortic diseases: infections, tumors, congenital anomalies]

Congenital malformations, tumors and aortic infections are rare and mostly asymptomatic. Unspecific clinical symptoms may cause delayed verification of the underlying disease. Contrast enhanced computer tomography- and magnetic resonance angiography are important sectional imaging methods for diagnostic completion. Consistent guidelines concerning diagnosis and therapy of rare aortic diseases are non-existent. Aortic tumors must be resected by open surgery, aortic infections in general require medical treatment and anomalies, if indicated, are treated more and more by endovascular or hybrid procedures. Therefore, it is recommended to treat these entities in an interdisciplinary approach in specialized aortic centers.

Abdominal aortic aneurysm in a patient with low back pain

STUDY DESIGN

Resident's case problem.

BACKGROUND

The purpose of this report was to describe (1) the clinical reasoning that led a clinician to identify an abdominal aortic aneurysm (AAA) in a patient with low back pain requiring immediate medical referral, and (2) an evidence-based approach to clinical evaluation of patients with suspected AAA.

DIAGNOSIS

The patient was unable to identify a specific mechanism of injury for his low back pain, lacked aggravating/easing factors for his symptoms, and complained of night pain and an inability to ease his symptoms with position changes. While the patient's symptoms remained unchanged during physical examination of the lumbar spine and hip, abdominal palpation revealed a strong, nontender pulsation over the midline of the upper and lower abdominal quadrants. Due to concern for an AAA, the patient was immediately referred to his physician. Subsequent computed tomography imaging revealed a prominent AAA, which measured up to 5.5 cm in greatest dimension and extended from below the renal arteries to the bifurcation of the iliac arteries. The patient initially deferred surgical intervention but eventually consented 6 months later, after repeat computed tomography imaging revealed that the AAA had progressed to 6.7 cm in greatest dimension.

DISCUSSION

It is essential for physical therapists to be familiar with a diagnostic pathway to help identify AAA in patients presenting with apparent musculoskeletal complaints. Knowledge of the risk factors for AAA, understanding how to screen for nonmusculoskeletal symptoms, and a basic competence in abdominal palpation and how to interpret findings will help with the clinician's clinical decision making.

LEVEL OF EVIDENCE

Differential diagnosis, level 4. J Orthop Sports Phys Ther 2014;44(7):500-507. Epub 25 April 2014. doi:10.2519/jospt.2014.4935.

Inflammatory Abdominal Aortic Aneurysm

We report a case of an abdominal aortic aneurysm (AAA) that underwent inflammatory transformation which we treated medically with corticosteroids. Medical therapy resulted in resolution of presenting symptoms and observed inflammatory changes. We review the clinical features, associated pathology, diagnostic, and therapeutic options in the management of inflammatory AAA.

[Acute rupture of an abdominal aortic aneurysm revealing Takayasu arteritis]

Arterial aneurysms are most commonly (60% of cases) located in the infrarenal abdominal aorta. An inflammatory mechanism is involved in only 10% of cases. Infrarenal abdominal aortic aneurysms revealing Takayasu's disease is unusual. Takayasu's disease is a rare vasculitis affecting large arteries in young people. It is 10 times more common in women. We report the case of an acute rupture of an abdominal aortic aneurysm revealing Takayasu arteritis in a 39-year-old man with an uneventful medical history.

Analysis of the effects of HIV-1 Tat on the survival and differentiation of vessel wall-derived mesenchymal stem cells

HIV infection is an independent risk factor for atherosclerosis development and cardiovascular damage. As vessel wall mesenchymal stem cells (MSCs) are involved in the regulation of vessel structure homeostasis, we investigated the role of Tat, a key factor in HIV replication and pathogenesis, in MSC survival and differentiation. The survival of subconfluent MSCs was impaired when Tat was added at high concentrations (200-1,000 ng/ml), whereas lower Tat concentrations (1-100 ng/ml) did not promote apoptosis. Tat enhanced the differentiation of MSC toward adipogenesis by the transcription and activity upregulation of PPARγ. This Tat-related modulation of adipogenesis was tackled by treatment with antagonists of Tat-specific receptors such as SU5416 and RGD Fc. In contrast, Tat inhibited the differentiation of MSCs to endothelial cells by downregulating the expression of VEGF-induced endothelial markers such as Flt-1, KDR, and vWF. The treatment of MSCs with Tat-derived peptides corresponding to the cysteine-rich, basic, and RGD domains indicated that these Tat regions are involved in the inhibition of endothelial marker expression. The Tat-related impairment of MSC survival and differentiation might play an important role in vessel damage and formation of the atherosclerotic lesions observed in HIV-infected patients.

Investigation and Treatment of a Complicated Inflammatory Aortoiliac Aneurysm

Inflammatory abdominal aortic aneurysms (IAAAs) account for 5% to 10% of all abdominal aortic aneurysms, occurring primarily in males. Their true etiology is unknown. Symptoms and signs of IAAA are so variable that they present to a wide range of specialties. There is debate in the literature whether IAAA is a manifestation of systemic autoimmune disease. We describe the case of a young female patient with complicated inflammatory aortoiliac aneurysmal disease, illustrating diagnostic and treatment challenges that remain. Our patient had a positive autoantibody screen, raised erythrocyte sedimentation rate, positive enzyme-linked immunosorbent spot test, and saccular aneurysms, including infective and inflammatory etiologies in her differential diagnosis. Early diagnosis is crucial to limit disease progression, morbidity, and mortality. Medical management is important to address the underlying disease process, but a combination of endovascular and open surgical intervention is often necessary for definitive treatment. Available evidence offers plausibility for benefit of endovascular intervention over open repair.

Myofibroblast-mediated adventitial remodeling: an underestimated player in arterial pathology

The arterial adventitia has been long considered an essentially supportive tissue; however, more and more data suggest that it plays a major role in the modulation of the vascular tone by complex interactions with structures located within intima and media. The purpose of this review is to summarize these data and to describe the mechanisms involved in adventitia/media and adventitia/intima cross-talk. In response to a plethora of stimuli, the adventitia undergoes remodeling processes, resulting in positive (adaptive) remodeling, negative (constrictive) remodeling, or both. The differentiation of the adventitial fibroblast into myofibroblast (MF), a key player of wound healing and fibrosis development, is a hallmark of negative remodeling; this can lead to vessel stenosis and thus contribute to major cardiovascular diseases. The mechanisms of fibroblast-to-MF differentiation and the role of the MF in adventitial remodeling are highlighted herein.

Infected aortic aneurysm and inflammatory aortic aneurysm--in search of an optimal differential diagnosis

Infected aortic aneurysm and inflammatory aortic aneurysm each account for a minor fraction of the total incidence of aortic aneurysm and are associated with periaortic inflammation. Despite the similarity, infected aortic aneurysm generally shows a more rapid change in clinical condition, leading to a fatal outcome; in addition, delayed diagnosis and misuse of corticosteroid or immunosuppressing drugs may lead to uncontrolled growth of microorganisms. Therefore, it is mandatory that detection of aortic aneurysm is followed by accurate differential diagnosis. In general, infected aortic aneurysm appears usually as a saccular form aneurysm with nodularity, irregular configuration; however, the differential diagnosis may not be easy sometimes for the following reasons: (1) symptoms, such as abdominal and/or back pain and fever, and blood test abnormalities, such as elevated C-reactive protein and enhanced erythrocyte sedimentation rate, are common in infected aortic aneurysm, but they are not found infrequently in inflammatory aortic aneurysm; (2) some inflammatory aortic aneurysms are immunoglobulin (Ig) G4-related, but not all of them; (3) the prevalence of IgG4 positivity in infected aortic aneurysm has not been well investigated; (4) enhanced uptake of 18F-fluorodeoxyglucose (FDG) by 18F-FDG-positron emission tomography may not distinguish between inflammation mediated by autoimmunity and that mediated by microorganism infection. Here we discuss the characteristics of these two forms of aortic aneurysm and the points of which we have to be aware before reaching a final diagnosis.

HIV-1 and recombinant gp120 affect the survival and differentiation of human vessel wall-derived mesenchymal stem cells

BACKGROUND

HIV infection elicits the onset of a progressive immunodeficiency and also damages several other organs and tissues such as the CNS, kidney, heart, blood vessels, adipose tissue and bone. In particular, HIV infection has been related to an increased incidence of cardiovascular diseases and derangement in the structure of blood vessels in the absence of classical risk factors. The recent characterization of multipotent mesenchymal cells in the vascular wall, involved in regulating cellular homeostasis, suggests that these cells may be considered a target of HIV pathogenesis. This paper investigated the interaction between HIV-1 and vascular wall resident human mesenchymal stem cells (MSCs).

RESULTS

MSCs were challenged with classical R5 and X4 HIV-1 laboratory strains demonstrating that these strains are able to enter and integrate their retro-transcribed proviral DNA in the host cell genome. Subsequent experiments indicated that HIV-1 strains and recombinant gp120 elicited a reliable increase in apoptosis in sub-confluent MSCs. Since vascular wall MSCs are multipotent cells that may be differentiated towards several cell lineages, we challenged HIV-1 strains and gp120 on MSCs differentiated to adipogenesis and endotheliogenesis. Our experiments showed that the adipogenesis is increased especially by upregulated PPARγ activity whereas the endothelial differentiation induced by VEGF treatment was impaired with a downregulation of endothelial markers such as vWF, Flt-1 and KDR expression. These viral effects in MSC survival and adipogenic or endothelial differentiation were tackled by CD4 blockade suggesting an important role of CD4/gp120 interaction in this context.

CONCLUSIONS

The HIV-related derangement of MSC survival and differentiation may suggest a direct role of HIV infection and gp120 in impaired vessel homeostasis and in genesis of vessel damage observed in HIV-infected patients.

Analysis of positional candidate genes in the AAA1 susceptibility locus for abdominal aortic aneurysms on chromosome 19

BACKGROUND

Abdominal aortic aneurysm (AAA) is a complex disorder with multiple genetic risk factors. Using affected relative pair linkage analysis, we previously identified an AAA susceptibility locus on chromosome 19q13. This locus has been designated as the AAA1 susceptibility locus in the Online Mendelian Inheritance in Man (OMIM) database.

METHODS

Nine candidate genes were selected from the AAA1 locus based on their function, as well as mRNA expression levels in the aorta. A sample of 394 cases and 419 controls was genotyped for 41 SNPs located in or around the selected nine candidate genes using the Illumina GoldenGate platform. Single marker and haplotype analyses were performed. Three genes (CEBPG, PEPD and CD22) were selected for DNA sequencing based on the association study results, and exonic regions were analyzed. Immunohistochemical staining of aortic tissue sections from AAA and control individuals was carried out for the CD22 and PEPD proteins with specific antibodies.

RESULTS

Several SNPs were nominally associated with AAA (p < 0.05). The SNPs with most significant p-values were located near the CCAAT enhancer binding protein (CEBPG), peptidase D (PEPD), and CD22. Haplotype analysis found a nominally associated 5-SNP haplotype in the CEBPG/PEPD locus, as well as a nominally associated 2-SNP haplotype in the CD22 locus. DNA sequencing of the coding regions revealed no variation in CEBPG. Seven sequence variants were identified in PEPD, including three not present in the NCBI SNP (dbSNP) database. Sequencing of all 14 exons of CD22 identified 20 sequence variants, five of which were in the coding region and six were in the 3'-untranslated region. Five variants were not present in dbSNP. Immunohistochemical staining for CD22 revealed protein expression in lymphocytes present in the aneurysmal aortic wall only and no detectable expression in control aorta. PEPD protein was expressed in fibroblasts and myofibroblasts in the media-adventitia border in both aneurysmal and non-aneurysmal tissue samples.

CONCLUSIONS

Association testing of the functional positional candidate genes on the AAA1 locus on chromosome 19q13 demonstrated nominal association in three genes. PEPD and CD22 were considered the most promising candidate genes for altering AAA risk, based on gene function, association evidence, gene expression, and protein expression.

Anesthesia for Open Abdominal Aortic Aneurysm Repair

Abdominal aortic aneurysms (AAAs) are the 13th leading cause of death in the United States 1 and approximately 40,000 patients undergo elective AAA repair each year.2 With the population aging, this number is expected to increase. Although the use of endovascular AAA repair is becoming more common, open repair, first reported by Dubost et al. in 1951 remains the gold standard.2 This chapter will review the etiology, risk factors, diagnosis, pathophysiology, operative technique, perioperative management, and postoperative complications of patients undergoing open AAA repair.

A case of inflammatory solitary internal iliac artery aneurysm successfully treated by an endovascular procedure

An inflammatory aneurysm localized in the iliac artery is very rare. Aneurysms of the common iliac artery have been reported sporadically, but there has been no report of internal iliac artery aneurysm. The patient was a 64-year-old male presenting with left lower abdominal pain and fever. Abdominal computed tomography (CT) revealed an aneurysm of 42 × 52 mm in the left internal iliac artery. The aneurysmal wall had thickened and mantle sign was positive. Since the aneurysm was expected to adhere tightly to surrounding tissues, the risk of open surgery was judged to be high, and coil embolization of the aneurysm and the peripheral branches of the internal iliac artery was performed. Postoperatively, the left lower abdominal pain disappeared, and signs of inflammation were mitigated. The endovascular procedure was extremely effective for the treatment of this inflammatory iliac artery aneurysm.