Hybrid Clampless Anastomosis in Antegrade Aorto-Superior Mesenteric Artery Bypass.

BACKGROUND: Bypass surgery in severe aorto-iliac calcifications is a complex procedure. Aortic clamping can be highly risky and endovascular approach can be unsuccessful. We report our experience describing three cases of chronic mesenteric ischemia. In all three cases the preoperative computed tomography angiography revealed an ostial occlusion of the celiac trunk and of the superior mesenteric artery (SMA), a coral reef abdominal aorta, and severe calcification of the iliac arteries. An antegrade aorto-mesenteric bypass using a hybrid clampless anastomosis on the supraceliac aorta was performed. RESULTS: The procedures were performed via laparotomy. We carried out the exposure of the anterior supraceliac aorta limited to the zone without major calcifications; then we performed a side-to-end media-adventitial anastomosis between the supraceliac aorta and a Dacron graft 7 mm without any arteriotomy or clamping. The proximal graft and the aortic anastomosis site were punctured using a 18 G needle. An introducer was then positioned over a wire through the prosthetic graft and pushed into the aorta. Balloon expandable covered stenting to open and stabilize the anastomosis site was performed. Finally, the graft was tunneled to the SMA, and an end-to-side anastomosis was performed. The postoperative courses were uneventful, and the patients were promptly discharged. The follow-up, which in the first case is 4 years, showed the complete patency of the graft in each of the cases treated. CONCLUSIONS: The hybrid clampless anastomosis appears to be safe and useful in cases of severe aortic calcification.

Human serum albumin Cys34 oxidative modifications following infiltration in the carotid atherosclerotic plaque.

OBJECTIVES: To evaluate if the prooxidant environment present in atherosclerotic plaque may oxidatively modify filtered albumin. METHODS: Fluorescein-5-maleimide labelled plasma samples and plaque extracts from 27 patients who had undergone carotid endarterectomy were analysed through nonreducing SDS-PAGE for albumin-Cys(34) oxidation. Furthermore, degree and pattern of S-thiolation in both circulating and plaque-filtered albumin were assayed. RESULTS: Albumin filtered in the atherosclerotic plaque showed higher levels of Cys(34) oxidative modifications than the corresponding circulating form as well as different patterns of S-thiolation. CONCLUSIONS: Data indicate that the circulating albumin, once filtered in plaque, undergoes Cys(34) oxidative modifications and demonstrate for the first time that albumin is a homocysteine and cysteinylglycine vehicle inside the plaque environment.

Proteomic analysis of plasma-purified VLDL, LDL, and HDL fractions from atherosclerotic patients undergoing carotid endarterectomy: identification of serum amyloid A as a potential marker.

Apolipoproteins are very heterogeneous protein family, implicated in plasma lipoprotein structural stabilization, lipid metabolism, inflammation, or immunity. Obtaining detailed information on apolipoprotein composition and structure may contribute to elucidating lipoprotein roles in atherogenesis and to developing new therapeutic strategies for the treatment of lipoprotein-associated disorders. This study aimed at developing a comprehensive method for characterizing the apolipoprotein component of plasma VLDL, LDL, and HDL fractions from patients undergoing carotid endarterectomy, by means of two-dimensional electrophoresis (2-DE) coupled with Mass Spectrometry analysis, useful for identifying potential markers of plaque presence and vulnerability. The adopted method allowed obtaining reproducible 2-DE maps of exchangeable apolipoproteins from VLDL, LDL, and HDL. Twenty-three protein isoforms were identified by peptide mass fingerprinting analysis. Differential proteomic analysis allowed for identifying increased levels of acute-phase serum amyloid A protein (AP SAA) in all lipoprotein fractions, especially in LDL from atherosclerotic patients. Results have been confirmed by western blotting analysis on each lipoprotein fraction using apo AI levels for data normalization. The higher levels of AP SAA found in patients suggest a role of LDL as AP SAA carrier into the subendothelial space of artery wall, where AP SAA accumulates and may exert noxious effects.

Association between Human Plasma Chondroitin Sulfate Isomers and Carotid Atherosclerotic Plaques.

Several studies have evidenced variations in plasma glycosaminoglycans content in physiological and pathological conditions. In normal human plasma GAGs are present mainly as undersulfated chondroitin sulfate (CS). The aim of the present study was to evaluate possible correlations between plasma CS level/structure and the presence/typology of carotid atherosclerotic lesion. Plasma CS was purified from 46 control subjects and 47 patients undergoing carotid endarterectomy showing either a soft or a hard plaque. The concentration and structural characteristics of plasma CS were assessed by capillary electrophoresis of constituent unsaturated fluorophore-labeled disaccharides. Results showed that the concentration of total CS isomers was increased by 21.4% (P < 0.01) in plasma of patients, due to a significant increase of undersulfated CS. Consequently, in patients the plasma CS charge density was significantly reduced with respect to that of controls. After sorting for plaque typology, we found that patients with soft plaques and those with hard ones differently contribute to the observed changes. In plasma from patients with soft plaques, the increase in CS content was not associated with modifications of its sulfation pattern. On the contrary, the presence of hard plaques was associated with CS sulfation pattern modifications in presence of quite normal total CS isomers levels. These results suggest that the plasma CS content and structure could be related to the presence and the typology of atherosclerotic plaque and could provide a useful diagnostic tool, as well as information on the molecular mechanisms responsible for plaque instability.

Carotid narrowing degree and plasma thiol levels in carotid endarterectomy patients.

The aim of this work was to study the association between plasma thiol levels and percentage carotid narrowing in a group of 68 patients who underwent a carotid endarterectomy, pertained as a risk factor for vascular and cardiovascular disease. Total plasma thiols were measured by capillary electrophoresis laser-induced fluorescence. The mean values of the hematological parameters studied were within normal limits and 25% of the patients were hyperhomocysteinemic (homocysteine >15 micromol/L). Pearson's correlation between carotid narrowing degree and the most common risk factors for atherosclerosis showed a positive relationship only between carotid narrowing degree and cysteine levels (r=0.252; p<0.05). Stepwise multiple linear regression with carotid narrowing degree as the dependent variable, and cysteine, homocysteine, age, triglyceride and low-density lipoprotein-cholesterol as independent variables confirmed that cysteine was significantly associated with these variables. By regrouping the population according to cysteine and homocysteine concentration percentiles, we found positive correlation between these parameters and median values of carotid narrowing degree. Our study provides experimental evidence to confirm that plasma homocysteine and cysteine are involved in carotid narrowing after carotid endarterectomy intervention, suggesting that cysteine may be involved in the deleterious molecular mechanisms active in carotid stenosis.

Circulating tissue kallikrein levels correlate with severity of carotid atherosclerosis.

BACKGROUND: Vascular growth factors are upregulated in stroke patients, but it remains unknown if they correlate with carotid atherosclerosis. METHODS AND RESULTS: A case-control study was conducted to determine: (1) possible association between biomarkers of angiogenesis or inflammation and carotid stenosis; and (2) the impact of revascularization on the same biomarkers. Circulating vascular endothelial growth factor (VEGF), basic fibroblast GF (bFGF), tissue kallikrein (tK), and high-sensitivity C-reactive protein (hs-CRP) were measured in 89 patients with carotid obstruction and 45 age-matched controls. Patients were stratified as <50% carotid stenosis (CAS; n=16); 50% to 69% CAS (n=12); 70% to 99% CAS (n=43); and carotid occlusion (CAO; n=18). No association was found between VEGF, bFGF, or hs-CRP and obstruction grading. TK augmented from 360+/-30 in <50% CAS (P=NS versus controls) to 509+/-72 in moderate CAS (P<0.05), 1159+/-178 in high-grade CAS (P<0.02), and 1616+/-403 pg/mL in CAO (P<0.01). A threshold of 508 pg/mL provided the maximized predictive value of high-grade obstruction. After revascularization, tK decreased from 1410+/-352 to 782+/-86 pg/mL (P<0.01), whereas no change was detected in nonoperated cases. Hs-CRP was unaffected by revascularization. CONCLUSIONS: Angiogenic factors are heterogeneously expressed in patients with carotid atherosclerosis. The tK measurement may be useful for the diagnosis and monitoring of atherosclerotic disease.