Popliteal artery aneurysms differ from abdominal aortic aneurysms in cellular topography and inflammatory markers.

OBJECTIVE: Popliteal artery aneurysms (PAAs) and abdominal aortic aneurysms (AAAs) frequently coincide; however, symptoms differ. We systematically assessed aneurysm cellular wall composition and inflammatory markers to compare both anatomic locations. METHODS: Aneurysmal walls of 38 PAAs and 198 AAAs were harvested from patients undergoing elective open surgical repair. Elastin, collagen, smooth muscle cells, iron, and inflammatory cells were quantified by immunohistochemistry. In addition, protease and cytokine levels were measured. RESULTS: Aneurysmal degradation resulted in similarly degraded media. The location of inflammation differed: the focus for T and B lymphocytes and plasma cells was the intima in PAAs (all P < .001) and the adventitia for AAAs (all P < .001). Iron was more often observed in PAAs than in AAAs (68% vs 1%; P < .001), indicating more previous intramural hemorrhages. Matrix metalloproteinase 2 activity was higher in PAAs than in AAAs (median [interquartile range], 0.363 [0.174-0.556] vs 0.187 [0.100-0.391]; P = .008), whereas matrix metalloproteinase 9 showed no difference. Walls of AAAs were richer in tested cytokine levels than were walls of PAAs. CONCLUSIONS: PAAs showed more signs of previous intramural hemorrhages compared with AAAs. In addition, inflammation in PAAs is mainly located in the intima, whereas its focus in AAAs is the adventitia. These results suggest important differences in the pathophysiologic mechanism of aneurysm formation between these locations and might explain the differences in presentation on diagnosis.

A clinicopathologic study of immunoglobulin G4-related disease of the femoral and popliteal arteries in the spectrum of immunoglobulin G4-related periarteritis.

BACKGROUND: Immunoglobulin (Ig) G4-related disease has recently been recognized to occur in the cardiovascular system in the aorta and main branching arteries, often manifesting as aneurysms and arteritis/periarteritis. Peripheral arteries (the femoral and popliteal arteries) are frequent sites of arteriosclerosis obliterans (ASO) and occasionally show aneurysms or arteritis. This study re-examined peripheral arterial lesions from the standpoint of IgG4-related disease. METHODS: The study comprised 104 patients who underwent surgical treatment of peripheral arterial lesions, including 30 patients with peripheral arterial aneurysms (PAAs) and 74 with ASO. IgG4-related disease was identified on the basis of diffuse infiltration of numerous IgG4-positive plasmacytes as revealed by immunohistochemical examination. Clinicopathologic features were compared between IgG4-related and IgG4-unrelated lesions. RESULTS: IgG4-related disease was found in four of the 30 patients with PAAs (13.3%; two in the deep femoral artery, two in the popliteal artery) but not in any patients with ASO. IgG4-related PAA displayed clinicopathologic features resembling those of other IgG4-related diseases and a characteristic saccular appearance (P = .002). CONCLUSIONS: IgG4-related disease was detected in PAA patients but not in ASO patients. IgG4-related disease thus represents one potential etiology of aneurysm in the peripheral arteries.

Antioxidized LDL antibodies are associated with different metabolic pathways in patients with atherosclerotic plaque and type 2 diabetes.

OBJECTIVE: Oxidized lipoproteins and antioxidized LDL antibodies (antioxLDL abs) have been detected in human plasma and atherosclerotic lesions. The principle aim of this study was to analyze the possible relationship between IgG and IgM antioxLDL abs and factors involved in different metabolic pathways (inflammation, lipid metabolism, apoptosis, and cell cycle arrest profile) in the occluded popliteal artery (OPA) compared with the femoral vein (FV). RESEARCH DESIGN AND METHODS: Fifteen patients with advanced atherosclerosis and type 2 diabetes undergoing lower limb amputation participated in this study. Each patient had OPA and FV biopsy specimens and peripheral arterial occlusive disease. By real-time PCR, gene expression was analyzed from the OPA and FV specimens, and antioxLDL ab levels were measured by specific enzyme-linked immunosorbent assay. RESULTS: The OPA and FV showed a positive correlation between only IgM antioxLDL ab levels and the expression of genes involved in different metabolic pathways, including inflammation (TFPI), apoptosis (BAX, caspase 3, AKT1), plaque disruption (MMP2 and MMP10), lipid metabolism (SCARB1, PPARg), and cell turnover (CDKN1A), and genes for transcription and growth factors (NFkB and VEGFA, respectively). CONCLUSIONS: The results show that gene expression in the metabolic pathways (apoptosis, lipid metabolism, and inflammation) in the OPA and FV are directly related to the levels of IgM antioxLDL abs.

Skin own bacteria may aggravate inflammatory and occlusive changes in atherosclerotic arteries of lower limbs.

AIM: Seroepidemiological studies have given rise to the hypothesis that microorganisms like Chlamydia pneumoniae (CP), Helicobacter pylori (HP), cytomegalovirus (CMV), HCV types 1 and 2, and bacteria involved in dental or other unspecified infection sites may initiate or maintain the atherosclerotic process in lower limb arteries. However, not much attention has been attached to the patient's own limb skin and deep tissues bacterial flora, activated in ischemic tissues. This flora may enhance the inflammatory and thrombotic process in the atherosclerotic arteries. Lower limb tissues are exposed to microorganisms from the environment (foot) and microbes on floating epidermal cells from the perineal and anal regions. The aim of this paper was to identify microbial cells and their DNA in perivascular tissues and arterial walls of lower limbs. METHODS: Bacterial cultures and PCR method for detection of 16sRNA and immunohistopathological staining for identification of immune cells infiltrating vascular bundles. RESULTS: 1) specimens of atherosclerotic calf and femoral arteries contained bacterial isolates and/or their DNA, whereas, in control normal cadaveric organ donors' limb arteries or patients' carotid arteries and aorta bacteria they were detected only sporadically; 2) lower limb lymphatics contained bacterial cells in 76% of specimens, whereas controls only in 10%; 3) isolates from limb arteries and lymphatics belonged in majority to the coagulase-negative staphylococci and S.aureus, however, other highly pathogenic strains were also detected; 4) immunohistopathological evaluation arterial walls showed dense focal infiltrates of granulocytes and macrophages. CONCLUSION: Own bacterial isolates can be responsible for dense neutrophil and macrophage inflitrates of atherosclerotic walls and periarterial tissue in lower limbs and aggravate the ischemic changes.

Inflammatory popliteal aneurysm.

A 67-year-old man was referred to our department because of fever, right lower thigh swelling, and redness with pain. Laboratory tests showed slightly elevated leukocytes and markedly elevated C-reactive protein levels. Computed tomography confirmed a popliteal aneurysm with wall thickening, so-called mantle sign. Aneurysmorrhaphy with a reversed autologous saphenous vein reconstruction was performed. Aneurysm sac and perianeurysm tissue cultures were negative for aerobic and anaerobic bacteria. The microscopic appearance of the aneurysm showed thickening of the adventitia and infiltration of inflammatory cells. This report presents, for the first time, findings suggestive of an inflammatory aneurysm of the popliteal artery.

Infected pseudoaneurysm of the femoral artery secondary to melioidosis infection of a previous femoropopliteal bypass graft.

Infected arterial aneurysm or pseudoaneurysm caused by Burkholderia pseudomallei is very rare; a review of the literature reveals only five previously reported cases. We report the first case of melioidosis infection of a previous femoropopliteal bypass graft complicated by para-anastomotic pseudoaneurysm of the femoral artery successfully treated by surgical removal of the old graft and creation of a new, extraanatomic, external iliac-to-popliteal bypass graft.

Systemic inflammatory parameters in patients with atherosclerosis of the coronary and peripheral arteries.

Plasma concentration of markers of inflammation are increased in patients with atherosclerosis. However, it is unclear whether the pattern and magnitude of this increase vary with the site and extent of disease. In 147 patients undergoing semiquantitative coronary angiography, we measured the acute-phase reactants C-reactive protein (CRP) or serum amyloid A (SAA); the proinflammatory cytokine interleukin 6 (IL-6); the active and total fractions of the anti-inflammatory cytokine transforming growth factor-beta (TGF-beta); the macrophage activation marker neopterin; and the infection marker procalcitonin. Compared with 62 patients without either coronary artery disease (CAD) or peripheral artery disease (PAD), 57 patients with CAD but no PAD showed greater median CRP (0. 4 versus 0.2 mg/dL, P=0.004) and IL-6 (3.8 versus 1.6 pg/mL, P=0. 007) levels and a lower level of active-TGF-beta (57 versus 100 ng/mL, P=0.038). Moreover, CRP, IL-6, and neopterin levels showed a positive and the active TGF-beta level a negative correlation with the extent of coronary atherosclerosis. Compared with these 57 patients with CAD alone, 15 patients with PAD and CAD had higher median levels of SAA (17 versus 7 mg/mL, P=0.008), IL-6 (12 versus 4 pg/mL, P=0.002), neopterin (14 versus 11 mg/dL, P=0.006), and total TGF-beta (11834 versus 6417 ng/L, P=0.001). However, these strong univariate associations of markers of inflammation and atherosclerosis were lost in multivariate analysis once age, sex, and high density lipoprotein cholesterol or fibrinogen were taken into account. Increased plasma levels of CRP, SAA, IL-6, TGF-beta, neopterin, and procalcitonin constitute an inflammatory signature of advanced atherosclerosis and are correlated with the extent of disease but do not provide discriminatory diagnostic power over and above established risk factors.

Leucocyte count: a predictor of early femoropopliteal graft failure.

The patency of 90 elective femoropopliteal reconstructions was assessed 6 months after surgery. The preoperative white cell count was found to be a highly significant predictor of early graft failure (P < 0.0001) independent of other previously recognized predictors of occlusion such as smoking and run-off.

Vasculo-Behçet's disease: immunological study of the formation of aneurysm.

We report two patients with vasculo-Behçet's disease who had femoral and popliteal aneurysms. The resected aneurysms and occluded distal arteries were studied clinicopathologically. The most interesting features were prominent fibrosis of the adventitia including the surrounding tissue, venous occlusion, perivasculitis and deposits of C3, C4 and immunoglobulins (IgA, IgG and IgM) in the arterial wall and surrounding tissue. These findings indicate that the formation of aneurysm in vasculo-Behçet's disease is caused by destruction of the intimal and outer side of the arterial wall.