Estimation of a minimum laser power with wavelengths of 1.47, 1.56, and 1.68 μm for efficient obliteration of varicose veins

Experiments modelling endovenous laser obliteration (EVLO) are performed. As a result, laser radiation powers Pc at which collagen denaturation, tissue necrosis, and vasa vasorum destruction occur throughout the entire venous-wall thickness and, at the same time, the surrounding tissues are not subjected to unnecessary heating, are found. The main criterion for determining Pc is the achievement of 100% denaturation of venous-wall proteins, confirmed by morphological and calorimetric analysis. The Pc values for laser wavelengths of 1.47, 1.56, and 1.68 mm are found to be 6.0 ± 0.2, 5.0 ± 0.2, and 6.0 ± 0.2 W, respectively. It is established for all wavelengths in use that the temperature of the external venous-wall surface reaches 91 plusmn; 2 deg;C at the corresponding power Pc. We relate the dependence of Pc on the radiation wavelength to the formation of a coagulum on the optical fibre tip moving through a blood-filled vessel. The achievement of temperature necessary for coagulum formation is determined by the simultaneously occurring processes of energy absorption and its dissipation in the form of heat. These processes become more intense with an increase in the absorption coefficient of the medium. A mechanism is proposed to explain the relationship between the Pc value and laser wavelength, based on the influence of the absorption coefficient of medium (blood) on the temperature near the fibre tip.

WRAPPING OF THE MODERATELY DILATED ASCENDING AORTA BY FRESH AUTOLOGOUS PERICARDIUM

Background and aim of the study. Wrapping of the ascending aorta (AA), isolated or associated with aortoplasty, has never been completely accepted. Some complications, as folding of the aortic wall, compression of the vasa vasorum and changes in the flow pattern, with consequent dilatation of the proximal arch, have been described. We used fresh autologous pericardium (FAP), so far never reported, to wrap the AA, with the aim to stabilize its size when moderately dilated, maintaining the preoperative dimension or limiting the reduction to a few mm. Material and Methods. From 2015 to 2019, 10 patients, who were operated on for valve or coronary surgery or both, underwent wrapping of the AA with FAP. Mean age was 69±7 years and ESII 3.5±1.7. Four patients had moderately impaired ejection fraction (35-49%). Results. There was no early or late mortality. One patient was reoperated on after 48 months for severe mitral regurgitation. At a follow up of 53±14 months, a transthoracic echocardiogram showed that the AA size reduced slightly but significantly, from 45.2±2.0 to 42.5±4.1 mm, p=0.03. The diameter of the proximal arch remained unchanged, from 37.1±1.6 to 36.3±2.9 mm, p=0.20. Conclusions. In presence of moderately dilated AA wrapping can be a reasonable option. The use of FAP stabilizes the size of the aorta after a follow up of 53 months. Maintaining a size similar to the preoperative one avoids the complications related to the procedure.

Randomized Clinical Trial to Evaluate the Morphological Changes in the Adventitial Vasa Vasorum Density and Biological Markers of Endothelial Dysfunction in Subjects with Moderate Obesity Undergoing a Very Low-Calorie Ketogenic Diet

Weight loss after bariatric surgery decreases the earlier expansion of the adventitial vasa vasorum (VV), a biomarker of early atheromatous disease. However, no data are available regarding weight loss achieved by very low calorie ketogenic diets (VLCKD) on VV and lipid-based atherogenic indices. A randomized clinical trial was performed to examine changes in adventitial VV density in 20 patients with moderate obesity who underwent a 6-month very low calorie ketogenic diet (VLCKD, 600–800 kcal/day), and 10 participants with hypocaloric diet based on the Mediterranean Diet (MedDiet, estimated reduction of 500 kcal on the usual intake). Contrast-enhanced carotid ultrasound was used to assess the VV. Body composition analysis was also used. The atherogenic index of plasma (log (triglycerides to high-density lipoprotein cholesterol ratio)) and the triglyceride-glucose index were calculated. Serum concentrations of soluble intercellular adhesion molecule 1 (sICAM-1), and soluble vascular cell adhesion molecule 1 (sVCAM-1) were measured. The impact of weight on quality of life-lite (IWQOL-Lite) questionnaire was administered. Participants of intervention groups displayed a similar VV values. Significant improvements of BMI (−5.3 [−6.9 to −3.6] kg/m2, p < 0.001), total body fat (−7.0 [−10.7 to −3.3] %, p = 0.003), and IWQOL-Lite score (−41.4 [−75.2 to −7.6], p = 0.027) were observed in VLCKD group in comparison with MedDiet group. Although after a 6-months follow-up period VV density (mean, right and left sides) did not change significantly in any group, participants in the VLCKD exhibited a significantly decrease both in their atherogenic index of plasma and serum concentration of sICAM-1. A 6-month intervention with VLCKD do not impact in the density of the adventitial VV in subjects with moderate obesity, but induces significant changes in markers of endothelial dysfunction and CV risk.

The Active Isoforms of MGP Are Expressed in Healthy and Varicose Veins without Calcification

Matrix Gla protein (MGP), a local inhibitor of tissue mineralization, is associated with vascular calcification. Depending on the carboxylation and phosphorylation status, MGP has active conformations, e.g., carboxylated MGP (cMGP) and phosphorylated MGP (pMGP), but also inactive conformations, e.g., uncarboxylated MGP (ucMGP) and dephosphorylated MGP (dpMGP). Our purpose was to assess the presence of all MGP conformations in healthy veins (HV) and varicose veins (VV), concurrently with the analysis of circulating total MGP (tMGP) before and after the surgical stripping of VV. We collected samples from the great saphenous vein, considered as control group, and tissue from VV, designated as VV group. Plasma levels of tMGP were significantly decreased after the surgical removal of the VV (before 59.5 ± 17.2 vs. after 38.1 ± 11.3, p < 0.001). By using immunohistochemistry staining, we identified local cMGP and pMGP in the control and VV groups, both without calcification, while ucMGP and dpMGP were absent. cMGP was observed in the nucleus and cytoplasm and pMGP in the nucleus of cells belonging to the tunica media, tunica intima and vasa vasorum. Therefore, the active conformations of MGP (cMGP and pMGP) are prevalent in HV and VV without calcification, affirming their anti-calcifying role in veins.

Bare Metal Stents on Resveratrol-Coated Balloons in Porcine Coronary and Peripheral Arteries

Balloon angioplasty and stent implantation are standard techniques to reopen stenotic vessels. Often, balloons or stents coated with cytostatic drugs are used to prevent re-occlusion of the arteries. Resveratrol, which is known for its numerous beneficial effects on cardiovascular health, is used as an antioxidant additive on paclitaxel-coated balloon catheters. What is still unclear is whether resveratrol-only balloon coating in combination with a bare metal stent (BMS) also has positive effects on vascular healing. Here, we analyzed neointimal thickening, fibrin deposition, inflammation, vasa vasorum density, and reendothelialization after implantation of BMS via a resveratrol coated balloon approach in a porcine model. In general, resveratrol treatment did not result in significantly altered responses compared to the control group in peripheral arteries. In coronary arteries, an increase in vasa vasorum density became evident three days after resveratrol treatment compared to the control group and abolished up to day 7. Significant effects of the resveratrol treatment on the fibrin score or intima-media area were transient and restricted to either peripheral or coronary arteries. In conclusion, local single-dose resveratrol treatment via a resveratrol-only coated balloon and BMS approach did not lead to adverse systemic or local effects, but also no significant beneficial effects on vascular healing were detected in the current study.

Atherosclerosis pathogenesis from the perspective of microvascular dysfunction

The article discusses different points of view on atherosclerosis development. The facts confirming the lipid hypothesis are presented. Attention is drawn to the possible participation of vasa vasorum in the development of atherosclerosis.

358. Early Cardiac Marker of Mortality in COVID-19

Background Epicardial adipose tissue (EAT) is a highly inflammatory depot of fat, with high concentrations of IL-6 and macrophages, which can directly reach the myo-pericardium via the vasa vasorum or paracrine pathways. TNF-α and IL-6 diminish cardiac inotropic function, making EAT inflammation a potential cause of cardiac dysfunction. Methods A retrospective cohort study assessing EAT Thickness and Density from CT scans, without contrast, from adult patients during index admission for COVID-19 infection at Mount Sinai Medical Center from March 2020 to January 2021. A total of 1,644 patients were screened, of which 148 patients were included. Follow-up completed until death or discharge. The descriptive analysis was applied to the general population, parametric test of normality for comparisons between groups. Kaplan survival analysis was conducted after survival distribution was confirmed significant. It was followed by the assumption of normality by Q-Q Plot, prior to performing a multiple regression analysis in the vulnerable group using a K-Matrix input for cofounders. A log-rank test was conducted to determine differences in the survival distributions for the different ranges of EAT thickness. Results A total of 148 Participants were assigned to two groups based on epicardial adipose tissue in order to classify them as increased or decreased risk of cardiovascular risk: &gt;5mm (n = 99), &lt; 5mm (n = 49). The survival percentage was higher in the group with no EAT inflammation compared to the group with EAT inflammation (95.0% and 65%, respectively). Participants with EAT &gt;5mm had a median day of hospital stay of 18 (95% CI, 16.86 to 29.92). The survival distributions for the two categories were statistically significantly different, χ2(2) = 6.9, p &lt; 0.01. A Bonferroni correction was made with statistical significance accepted at the p &lt; 0.025 level. There was a statistically significant difference in survival distributions for the EAT &gt;5 mm vs EAT &lt; 5 mm, χ2(1) =6.953, p = 0.008. EAT Thickness Survival Analysis 2020-2021 COVID-19 MSMC Scatter Plot Length of Stay by EAT Thickness Conclusion There was an association with increased EAT thickness and increased mortality. These findings suggest that EAT thickness can be used as a prognostic factor and as a risk factor for increased mortality in patients with COVID-19 Disclosures All Authors: No reported disclosures

Rho Kinase Expression in Giant Cell Arteritis Validating pERM Intensity Score as a Method of Increasing Sensitivity of Temporal Artery Biopsy

Background: Aberrant rho-kinase (ROCK) activity is implicated in pathogenesis of several vascular and immunologic disorders. We previously demonstrated evidence of increased ROCK activity in histopathologically negative temporal artery biopsies (TAB) of subjects with clinical Giant Cell Arteritis (GCA) compared to those without GCA. This study aimed to examine ROCK activity in a larger cohort of biopsy-negative GCA subjects and to validate the prior findings. Methods: Subjects were categorized into 2 groups based on clinical data 6-months after TAB: biopsy-negative GCA and controls without GCA. Paraffin-embedded TAB were stained for phosphorylated ezrin/radixin/moesin (pERM), a surrogate of ROCK activity, and scored by two pathologists blinded to clinical diagnosis using a previously derived scoring system. Three areas of the vessel (intima, adventitial and vasa vasorum) were scored for staining intensity on a scale of 0–2, with a maximum possible score of 6 for each TAB. As determined a priori, scores ³4 were considered a high pERM intensity score correlating with ROCK activity. TAB sections were also stained for unphosphorylated ERM, the inactive protein. Results: Thirty six subjects with biopsy-negative GCA and 43 controls were analyzed. There were no differences between groups in age, sex and corticosteroid dose. The mean pERM intensity score in non-GCA subjects was 3.9 ± 1.4 (compared to 5.0 ± 1.4 in those with GCA, p = 0.002). Using the predetermined cut-off of 4 to define high pERM intensity, subjects with GCA were significantly more likely to have a high pERM intensity score compared to non-GCA, OR 3.67, 95%CI :1.19,11.36; p= 0.019. The sensitivity of high pERM intensity score for diagnosis of GCA in histologically negative TAB was 86%, 95%CI: 70,95. Conclusions:. In this well characterized cohort, those with GCA and negative biopsies had significantly higher pERM intensity scores in TAB specimens compared to subjects without GCA. pERM staining has diagnostic significance in enhancing the sensitivity of TAB, and helps to define the clinically important group of biopsy-negative GCA. The ROCK pathway warrants further investigation in GCA and may be a potential therapeutic target

Vasa vasorum of proximal cerebral arteries after dural crossing — potential imaging confounder in diagnosing intracranial vasculitis in elderly subjects on black-blood MRI

Objectives Vessel wall enhancement (VWE) may be commonly seen on MRI images of asymptomatic subjects. This study aimed to characterize the VWE of the proximal internal carotid (ICA) and vertebral arteries (VA) in a non-vasculitic elderly patient cohort. Methods Cranial MRI scans at 3 Tesla were performed in 43 patients (aged ≥ 50 years) with known malignancy for exclusion of cerebral metastases. For vessel wall imaging (VWI), a high-resolution compressed-sensing black-blood 3D T1-weighted fast (turbo) spin echo sequence (T1 CS-SPACE prototype) was applied post gadolinium with an isotropic resolution of 0.55 mm. Bilateral proximal intradural ICA and VA segments were evaluated for presence, morphology, and longitudinal extension of VWE. Results Concentric VWE of the proximal intradural ICA was found in 13 (30%) patients, and of the proximal intradural VA in 39 (91%) patients. Mean longitudinal extension of VWE after dural entry was 13 mm in the VA and 2 mm in the ICA. In 14 of 39 patients (36%) with proximal intradural VWE, morphology of VWE was suggestive of the mere presence of vasa vasorum. In 25 patients (64 %), morphology indicated atherosclerotic lesions in addition to vasa vasorum. Conclusions Vasa vasorum may account for concentric VWE within the proximal 2 mm of the ICA and 13 mm of the VA after dural entry in elderly subjects. Concentric VWE in these locations should not be confused with large artery vasculitis. Distal to these segments, VWE may be more likely related to pathologic conditions such as vasculitis. Key Points • Vasa vasorum may account for concentric VWE within the proximal 2 mm of the ICA and 13 mm of the VA after dural entry in non-vasculitic elderly people. • Concentric enhancement within the proximal 2 mm of the intradural ICA and within the proximal 13 mm of the intradural VA portions should not be misinterpreted as vasculitis. • Distal of this, VWE is likely related to pathologic conditions, in case of concentric VWE suggestive of vasculitis.