Patch Neointima Technique in Acute Type A Aortic Dissection: Midterm Results of 147 Cases.

BACKGROUND: The patch neointima technique is a modified valve-sparing aortic root repair surgery for acute type A aortic dissection and the short-term outcomes are satisfactory. The midterm outcomes have not been reported. METHODS: From January 2009 to December 2012, 147 patients underwent valve-sparing aortic root repair with the patch neointima technique for type A aortic dissection in our center. The midterm outcomes of the patients were evaluated by echocardiography and aortic computed tomography angiography. RESULTS: Of 147 patients, 32 patients (21.8%) underwent proximal arch repair, and 115 patients (78.2%) underwent proximal arch repair combined with triple-branched stent graft implantation. The perioperative mortality was 5.4%. Preoperative aortic insufficiency (AI) was observed in 94 patients (63.9%); 131 patients (89.1%) left the operating room with 0 AI; the remaining 16 patients (10.9%) had trace or less than 1+ AI. A total of 128 patients (87.1%) completed 7-year follow-up. The mean follow-up time was 5.7 ± 1.2 years. As many as 82% of patients (105) were 0 AI and 15.6% of patients (20) were 0.5+ trace or less than 1+ AI. No reoperation was performed for the aortic root. The diameters of sinotubular junction and sinus were reduced to the normal range (28.3 ± 4.2 mm and 30.5 ± 3.6 mm, respectively) and remained stable (28.9 ± 5.6 mm, P = .300, and 30.8 ± 4.2 mm, P = .540, respectively) during 7 years of follow-up. CONCLUSIONS: Valve-sparing aortic root repair with patch neointima technique was associated with stable function of the aortic valves and no expansion of the aortic root in the midterm.

Photochemical Tissue Passivation of Arteriovenous Grafts Prevents Long-Term Development of Intimal Hyperplasia in a Swine Model.

BACKGROUND: The autologous vein remains the standard conduit for lower extremity and coronary artery bypass grafting despite a 30%-50% 5-y failure rate, primarily attributable to intimal hyperplasia (IH) that develops in the midterm period (3-24 mo) of graft maturation. Our group discovered that externally strengthening vein grafts by cross-linking the adventitial collagen with photochemical tissue passivation (PTP) mitigates IH in an arteriovenous model at 4 wk. We now investigate whether this effect is retained in the midterm period follow-up. METHODS: Six Hanford miniature pigs received bilateral carotid artery interposition vein grafts. In each animal, the external surface of one graft was treated with PTP before grafting, whereas the opposite side served as the untreated control. The grafts were harvested after 3 mo. Ultrasound evaluation of all vein grafts was performed at the time of grafting and harvest. The grafts were also evaluated histomorphometrically and immunohistologically for markers of IH. RESULTS: All vein grafts were patent at 3 mo except one graft in the PTP-treated group because of early technical failure. The control vein grafts had significantly greater IH than PTP-treated grafts at 3 mo, as evidenced by the intimal area (2.6 ± 1.0 mm2versus 1.4 ± 1.5 mm2, respectively, P = 0.045) and medial area (5.1 ± 1.9 mm2versus 2.7 ± 2.4 mm2, respectively, P = 0.048). The control grafts had an increased presence and proliferation of mural myofibroblasts with greater smooth muscle actin and proliferating cell nuclear antigen staining. CONCLUSIONS: PTP treatment to the external surface of the vein grafts decreases IH at 3 mo after arteriovenous grafting and may prevent future graft failure.

Biochemical markers in blood serum of patients undergoing various methods of carotid endarterectomy. / Biokhimicheskie markery syvorotki krovi pri razlichnykh metodakh karotidnoi éndarteréktomii.

The authors studied the concentration of CRP, sE-selectin, sP-selectin, sICAM-1, sICAM-3, sVCAM-1, sPECAM and endothelin-1 in blood serum of patients presenting with stenotic lesions of carotid arteries and undergoing various methods of carotid endarterectomy (CEAE): eversion CEAE (Group I) and CEAE using a xenopericardium patch (Group II). Within the time frame of the study, patients in both groups were found to have an elevated CRP level in the early postoperative period, having returned to the baseline values at 6 postoperative months, as well as an increase in the concentration of endothelin-1 at six months after surgery and a decrease of the sE-selectin concentration in the early postoperative period. The level of sP-selectin in Group II patients was noted to increase considerably six months after correction of stenosis. The content of sICAM-1 and sVCAM-1 did not differ in the early postoperative and baseline periods, and was noted to decrease 6 months after the operation. Group II patients demonstrated a decrease in the sPECAM concentration during postoperative day one, followed by returning to the initial values six months after CEAE. The above-mentioned biochemical markers may be used during the postoperative follow-up period for early detection and appropriate correction of endothelial dysfunction and hyperplasia of the intima of the zone of reconstruction.

[Study of patency of vascular grafts manufactured by means of electrospinning].

UNLABELLED: In vivo experiments were carried out to study functioning of vascular grafts manufactured by means of electrospinning from solutions of polycaprolactone (PCL) and hexafluoroisopropanol (HFIP), PCL with 10% gelatine and a low-permeability inner layer (LPIL) 10 µm thick and PCL with 10% gelatine and LPIL (10 µm) wherein as polymeric base instead of PCL copolymer of lactic and hydroxyacetic acids (polylactide-co-glycolide, PLGA) was used. The grafts were implanted into the infrarenal portion of the aorta to 45 rats, 15 rats for each type of the graft. Patency of artificial vessels was assessed by means of magnetic resonance tomography and diagnostic ultrasound Dopplerography at 2, 4 and 20 weeks (5 animals for each time point). The state of the graft and surrounding tissues was analysed by means of intraoperative assessment, survey microscopy and survey fluorescent microscopy. CONCLUSION: The obtained findings demonstrated that vascular grafts made by electrospinning technique with a low-permeability inner layer are less prone to formation of the neointima and stenosing as compared with grafts having no such layer.

Early Phase Arterial Reaction Following Drug-Eluting and Bare-Metal Stent Implantation in Patients With ST-Segment Elevation Myocardial Infarction.

The early phase arterial reaction after implantation of second-generation drug-eluting stents (2nd DES) and baremetal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI) remains unclear.The MECHANISM pilot study is a multi-center prospective registry that enrolled 24 STEMI patients (from 11 centers) who had undergone implantation of everolimus-eluting (n = 6), biolimus A9-eluting (n = 6) or zotarolimus-eluting stents (n = 6), or BMS (n = 6). Scheduled optical coherence tomography (OCT) was performed 2 weeks after implantation, and images were independently analyzed at a core laboratory in a blinded fashion. Intra-stent thrombus was quantitatively analyzed in terms of the maximal area and the percentage of cross-sections with thrombus (the numbers of cross-section with thrombus × 100 divided by total number of cross-sections within the stented segment). More than 90% of struts were already covered 2 weeks after the index procedure, regardless of the stent type. There were no differences in stent diameter, minimal lumen diameter, minimal lumen area, neointimal thickness, or the frequencies of malapposed and uncovered struts among the 4 groups. The quantity of intra-stent thrombus also did not differ among the 4 groups.The results of this pilot study suggest that the 2-week vascular responses seem to be similar among 2nd DES and BMS in STEMI patients. Considering the possible advantage of 2nd DES in the prevention of restenosis, 2nd DES are a feasible option for the treatment of patients with STEMI.

Circumferential distribution of the neointima at six-month and two-year follow-up after a bioresorbable vascular scaffold implantation: a substudy of the ABSORB Cohort B Clinical Trial.

AIMS: To investigate the extent and the circumferential distribution of the neointima tissue developed following an Absorb bioresorbable vascular scaffold (BVS) implantation. METHODS AND RESULTS: Twenty-three patients who were treated with the Absorb BVS and had optical coherence tomographic examination after scaffold implantation, at six-month and at two-year follow-up, were included in the current analysis. The lumen and the scaffold borders were detected and the circumferential thickness of the neointima was measured at one degree intervals. The symmetry of the neointima was defined as: minimum/maximum thickness. The lumen area was decreased at six months compared to baseline but it did not change between six-month and two-year follow-up (baseline: 7.49 [6.13-8.00] mm², six months: 6.31 (4.75-7.06) mm², two years: 6.01 [4.67-7.11] mm², p=0.373). However, the mean neointima thickness (six months: 189 [173-229] m, two years: 258 [222-283] m, p<0.0001) and the symmetry index of the neointima (six months: 0.06 [0.02-0.09], two years: 0.27 [0.24-0.36], p<0.0001) were increased at two years. Full circumferential coverage of the vessel wall by neointima tissue was seen in 91% of the studied frames at two years. CONCLUSIONS: This study demonstrates that after an Absorb BVS implantation neointima tissue develops that covers almost the whole circumference of the vessel wall. In contrast to the metallic stents, the neointima tissue does not compromise the luminal dimensions. Further research is required to evaluate the neointimal characteristics and assess the potential value of the device in passivating high-risk plaques.

Experimental evaluation of efficacy and healing response of everolimus-eluting stents in the familial hypercholesterolemic swine model: a comparative study of bioabsorbable versus durable polymer stent platforms.

BACKGROUND: The utility of animal models for the prediction of drug-eluting stent (DES) efficacy in human clinical trials is still unclear. The familial hypercholesterolemic swine (FHS) model has been shown to induce a human-like neointimal response to bare metal stent (BMS) implantation. However, its utility to discriminate efficacy signals following DES implantation is unknown. In this study, we aimed to test the efficacy and healing response of several everolimus-eluting stent (EES) platforms in the coronary territory of the FHS. METHODS: A total of 19 EES platforms (SYNERGY=6, SYNERGY½-dose=7, and PROMUS Element=6) and an identical BMS control (Element=6) were implanted into the coronary arteries of nine FHS. All implants were performed under intravascular ultrasound guidance using a 1.2 : 1 overstretch ratio. At 30 days, the vascular response to the implant was evaluated by quantitative coronary angiography, optical coherence tomography, and histology. RESULTS: At 28 days, all EES platforms showed a significant decrease in angiographic late lumen loss (between 27 and 37%) compared with the BMS control group. This finding was confirmed both by optical coherence tomography (mean neointimal thickness=28-42% reduction) and by histology (mean neointimal thickness=44-55% reduction). All EES platforms showed similar degrees of neointimal inhibition. The presence of moderate to severe para-strut inflammation was observed in 83% of the stent sections in the BMS group compared with 28.6% in the SYNERGY½-dose group and 0% in the SYNERGY and PROMUS groups (P=0.0002). There was a 68-95% reduction in MMP9 expression in the media in all EES platforms compared with the BMS controls. The presence of mild to moderate para-strut fibrin deposits ranged from 66.7 to 83.4% in all EES platforms compared with 16.7% in the EBMS group. CONCLUSION: The FHS coronary injury model showed the efficacy of several EES platforms compared with an identical BMS control. Everolimus eluted from different polymeric platforms showed lower levels of inflammation and slightly higher fibrin deposits compared with BMS controls.

Cardiac markers following cardiac surgery and percutaneous coronary intervention.

Differentiation between procedure-related necrosis and postprocedural myocardial infarction (MI) is challenging because of the inherent association of these procedures to varying levels of myocardial injury. To improve risk stratification of patients at risk of an acute MI, the universal definition of MI implemented cardiac biomarker thresholds. The cutoff points for these thresholds, however, are largely arbitrary and lack therapeutic implications. Measurement of cardiac marker concentrations after percutaneous coronary intervention and cardiac surgery should, therefore, be used as a marker of baseline risk, atherosclerosis burden, and procedural complexity rather than a conclusive marker to diagnose acute MI.

The possibility of delayed arterial healing 5 years after implantation of sirolimus-eluting stents: serial observations by coronary angioscopy.

BACKGROUND: Although very late stent thrombosis occurs several years after implantation of sirolimus-eluting stent (SES), the morphologic changes of the stent beyond 2 years have not yet been systematically studied in living patients. The late vascular response to SES was therefore evaluated by serial angioscopic studies at 2 and 5 years after stent implantation. METHODS: A total of 17 patients with 17 SES underwent a repeated angioscopy procedure at 2 and 5 years. Neointimal stent coverage (NSC) was classified as follows: grade 0, presence of uncovered struts; grade 1, visible struts through a thin neointima; or grade 2, complete neointimal coverage without visible struts. For each patient, the minimum and maximum NSC grade and the existence of in-stent thrombus were recorded. RESULTS: The minimum and maximum NSC grade did not increase between the 2 and 5 years (0.59 ± 0.51 vs 0.88 ± 0.70, P = .17, and 1.82 ± 0.39 vs 1.94 ± 0.24, P = .30, respectively). The prevalence of patients with uncovered struts did not significantly decrease from 2 to 5 years (41% vs 29%, P = .49). During the follow-up period, 3 of 6 thrombi disappeared, whereas new thrombus formation was found in 3 patients without any clinical symptoms. In-stent thrombus did not decrease (35% vs 35%, P > .99). CONCLUSIONS: The current serial angioscopic study suggests that incomplete NSC and the prevalence of latent thrombus within the SES segments did not decrease from 2 to 5 years. The risk of stent thrombosis related to incomplete healing of SES may continue for an extended period.