Anticoagulation Management Post Pulmonary Embolism

Pulmonary embolus (PE) carries a significant impending morbidity and mortality, especially in intermediate and high-risk patients, and the choice of initial anticoagulation that allows for therapeutic adjustment or manipulation is important. The preferred choice of anticoagulation management includes direct oral anticoagulants. Vitamin K antagonists and low-molecular-weight heparin are preferred in special populations or selected patients such as breastfeeding mothers, those with end-stage renal disease, or obese patients, among others. This article reviews the primary and longer-term considerations for anticoagulation management in patients with PE and highlights special patient populations and risk factor considerations.

Interleukin-13: association with inflammation and cysteine proteolysis in varicose transformation of the vascular wall

The present review considers current data on the structure, functions and role of interleukin-13 in the pathogenesis of vascular wall varicose transformation in terms of proteolysis and inflammatory response. It is known that interleukin-13 is able to interact with transforming growth factor-1 in diseases associated with fibrosis. The latter activates fibroblasts and excessive formation of the extracellular matrix, thereby inducing fibrosis of the vascular wall, which is one of the links in the pathogenesis of varicose veins. Also, to date, there is evidence of the interleukin-13 participation in the induction of certain proteolytic enzymes synthesis, such as matrix metalloproteinases. For the latter, participation in the transformation of the venous wall has been proven to date. The remodeling of the venous wall itself can lead to an increase in the expression of proteinases, providing a proteolytic mechanism for changing the structural organization of the venous wall in varicose veins of the lower extremities. At the same time, the involvement of lysosomal cysteine proteinases remains poorly understood. The expression and production of individual cathepsins are regulated by biologically active molecules: interleukin-1, interleukin-6, tumor necrosis factor , which are directly involved in inflammatory reactions in the wall of varicose veins. In particular, venous pathology develops in a vicious circle of inflammation with the formation of abnormal venous blood flow, chronic venous hypertension and dilation, and the recruitment of leukocytes. This leads to a further, deeper, remodeling of the walls and valves of the veins, an increase in blood pressure and the release of pro-inflammatory mediators chemokines and cytokines. In connection with the above, in order to understand the mechanisms of proteolysis in the vascular wall in varicose veins of the lower extremities, it is important to have an idea about the possible interactions of interleukin-13 with transforming growth factor-1, inflammatory cytokines, and cathepsins.

OUP accepted manuscript

Venous ulcers are common and account for the majority of lower limb chronic wounds. Complications may be serious in nature and although haemorrhage is rare, it may be rapidly fatal. The case of a female patient who presented with a spontaneous varicose ulcer haemorrhage causing hypovolaemic ischaemic colitis is described. This case exemplifies the need to identify and manage the development of venous insufficiency before progression to chronic wounds or other disease burdens which may be fatal or life-altering.

Transforming growth factor-β1 and inducible nitric oxide synthase signaling were involved in effects of prostaglandin E2 on progression of lower limb varicose veins

OBJECTIVE

The vital pathogenesis of varicose veins includes remodeling of the extracellular matrix and decreased vascular tone. Prostaglandin E₂ (PGE₂), a small molecule substance and inflammatory medium that belongs to the arachidonic acid derivatives, has the capacity to influence the expression of metalloproteinase and the vascular tone of the venous wall. The purpose of the present study was to investigate the role of PGE₂ in the development of varicose veins in lower limbs.

METHODS

The collected venous specimens were analyzed using hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining. Transforming growth factor (TGF)-β1, PGE₂, CD31, and α-smooth muscle actin antibody were used to detect the expression and distribution of these proteins. The effect of PGE₂ on the proliferation, migration, and tube formation capacity of human umbilical vein endothelial cells (HUVECs) was detected in vitro. The effect of TGF-β1 on the expression of PGE₂ and matrix metalloproteinases (MMPs) was assessed using Western blotting. Quantitative reverse transcription polymerase chain reaction was used to evaluate the effect of PGE₂ on the expression of nitric oxide synthase (NOS) and other genes.

RESULTS

The expression of PGE₂ and TGF-β1 in varicose veins was upregulated in the media tunica and intima tunica, and a strong positive correlation was found between PGE₂ and TGF-β1 expression in both varicose veins (95% confidence interval, 0.5207-0.9582; R = 0.848; P = .0005) and normal veins (95% confidence interval, 0.2530-0.8532; R = 0.643; P = .003). PGE₂ promoted the migration and tube formation ability of HUVECs. Moreover, PGE₂ also upregulated the expression of MMP-1 and TGF-β1 in HUVECs and increased the mRNA level of inducible NOS.

CONCLUSIONS

PGE₂ can affect the remodeling of the extracellular matrix and reduce the elasticity of the vascular walls by promoting the synthesis of TGF-β1 and MMP-1. PGE₂ can also reduce the tension of the great saphenous vein by promoting the expression of inducible NOS, thus aggravating the blood stasis.

Therapeutic potential of flavonoids in the treatment of chronic venous insufficiency

Chronic venous insufficiency (CVI) is a common disorder associated with a variety of symptoms in later disease stages; despite the high prevalence of this pathology, suitable pharmaceutical therapies have not been explored to date. In this context, it was recently reported that a chronic increase in venous wall stress or biomechanical stretch is sufficient to cause development of varicose veins. Recent evidence demonstrate that flavonoids are natural substances that convey the circulatory system functionality, playing a key role in blood flow. Particularly, troxerutin, diosmin and horse chestnut extract, appear protective for the management of vascular diseases. The aim of the present study was to evaluate the effect of a flavonoid compound, containing troxerutin, diosmin and horse chestnut extract on in vitro model on HUVECs cells, due to its production of vasculoregulatory and vasculotropic molecules, on an ex-vivo model on mesenteric vessel contraction, to regularize mesenteric microcirculation and on in vivo model of CVI-induced by saphene vein ligation. Furthermore, the flavonoid compound capacity of extensibility and compatibility with peripheral veins was investigated through a tissue block culture study. The degree of absorption, the contractile venous activity, the histological analysis, the immunoistochemical and immunofluorescence evaluation for VEGF and CD34 were performed, together with inflammatory mediators dosage. For the first time, this research revealed the therapeutic potential of a compound, enriched with flavonoids, to be a supportive treatment, suitable to reduce varicose vein pathophysiology and to regularize venous tone.

Thermal characteristics of non-biological vessel phantoms for treatment of varicose veins using high-intensity focused ultrasound

The ultrasonic treatment of varicose veins uses high-intensity focused ultrasound, in which a blood vessel is contracted by converting acoustic energy into thermal energy. In this study, we propose a phantom of varicose veins that can be applied for the efficient evaluation of ultrasonic treatment in varicose veins. The proposed phantom consisted of glycerol base tissue equivalent material, vessel mimic tube, and blood mimic substances. The vessel mimic tube was placed inner glycerol phantom and it was filled with blood mimic substances. Blood-mimicked substances are prepared by adjusting the concentration of the glycerol solution to be similar to the acoustic properties of the blood, and vessel-mimicking materials are selected by measuring acoustic properties and thermal shrinkage of various materials in a heat-shrinkable tube. The blood vessels surrounding the tissue are replaced with the phantom similar to glycerol-based organization, and venous blood flow is implemented using a DC motor. The heating characteristics according to the ultrasonic wave using the manufactured varicose veins phantom were evaluated. As the sound wave irradiation time and power increased, the contractility of the vessel mimicking materials and the temperature of the surrounding tissues were increased. When the blood-mimicking material was circulated, the highest temperature in the focused region and the contractility of vessel mimicking materials were reduced under the same conditions as used for sonication. The manufactured phantom may contribute to the treatment of varicose veins and can be used to predict the ultrasonic therapeutic efficiency of varicose veins.

News in Pathogenesis of Chronic Venous Insufficiency

This review article is concentrating on the news in the pathophysiology of chronic venous insufficiency (CVD). Despite ongoing progress in understanding the molecular aspects of CVD the exact mechanism of its development remains unclear. Many different factors may play role in the pathogenesis of CVD, including changes in hydrostatic pressure, valvular incompetence, increased capillary permeability, endothelial dysfunction, activation of leukocytes, deep venous obstruction, capillary microthrombosis, ineffective function of calf muscle pump, biochemical and structural changes in the vessel wall, extracellular matrix alteration, and several other mechanisms. A better understanding of the pathophysiology is an important step in the finding of new potential treatment.

Morphology and Progression in Primary Varicose Vein Disorder Due to 677C>T and 1298A>C Variants of MTHFR

Background

Clinical assessment and prognostic stratification of primary varicose veins have remained controversial and the molecular pathogenesis is unknown. Previous data have suggested a contribution of the MTHFR (methylenetetrahydrofolate reductase) polymorphism c.677C>T.

Methods

We collected blood and vein specimens from 159 consecutive patients undergoing varicose vein surgery, or autologous vein reconstruction for arterial occlusive disease as controls. We compared the frequencies of c.677C>T and another polymorphism of MTHFR, c.1298A>C, with morphology and types of complicated disease. Morphology was recorded as a trunk or perforator type and peripheral congestive complication was defined as chronic venous insufficiency (CEAP C3–6) associated with edema and skin manifestations.

Findings

Multivariate analysis of genotypes for c.677C>T and c.1298A>C indicated that c.677C>T was associated significantly with the trunk phenotype (43/53 patients, 81%, p < 0.01), while c.1298A>C was associated significantly with the perforator phenotype (18/24 patients, 75%, p < 0.01) of primary varicose veins. Accordingly, when both c.677C>T and c.1298A>C displayed a heterozygous genotype, the patients were more likely to present with both phenotypes. Additionally, c.1298A>C was found to be strongly linked to the congestive complication (34/51 patients, 67%, p < 0.01).

Interpretation

Both polymorphisms of MTHFR may be involved in the morphological specification of primary varicose veins and contribute to the development of complicated disease.

Funding

None.

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MTHFR polymorphism c.677C>T characterizes axial trunk and c.1298A>C perforator type morphology in primary varicose veins.

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Mutant genotypes are associated with complicated phenotypes of the disease.

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Genetic hint for distinct perforator type morphology associating further with congestive (CEAP C3–6) disease is provided.

Genetic polymorphisms of vein wall remodeling in chronic venous disease: a narrative and systematic review

Chronic venous disease encompasses a spectrum of disorders caused by an abnormal venous system. They include chronic venous insufficiency, varicose veins, lipodermatosclerosis, postthrombotic syndrome, and venous ulceration. Some evidence suggests a genetic predisposition to chronic venous disease from gene polymorphisms associated mainly with vein wall remodeling. The literature exploring these polymorphisms has not been reviewed and compiled thus far. In this narrative and systematic review, we present the current evidence available on the role of polymorphisms in genes involved in vein wall remodeling and other pathways as contributors to chronic venous disease. We searched the EMBASE, Medline, and PubMed databases from inception to 2013 for basic science or clinical studies relating to genetic associations in chronic venous disease and obtained 38 relevant studies for this review. Important candidate genes/proteins include the matrix metalloproteinases (extracellular matrix degradation), vascular endothelial growth factors (angiogenesis and vessel wall integrity), FOXC2 (vascular development), hemochromatosis (involved in venous ulceration and iron absorption), and various types of collagen (contributors to vein wall strength). The data on associations between these genes/proteins and the postthrombotic syndrome are limited and additional studies are required. These associations might have future prognostic and therapeutic implications.

Effects of surgery on microvascular function in venous insufficiency

BACKGROUND

The aim of our study was to assess the effects of venous stripping on microvascular functions in isolated great saphenous vein insufficiency.

METHODS

Two groups of participants were prospectively evaluated. The first group included 15 healthy participants without any evidence of venous insufficiency. The second group included 20 patients with varicose veins because of great saphenous vein insufficiency. The demographics, venous clinical severity scores, and CEAP classifications of the patients were recorded. Next, all individuals underwent evaluations for microvascular vasoreactivity using an iontophoretic laser Doppler imager, and the outcomes were recorded. Patients with varicose veins underwent stripping surgeries, and microvascular vasoreactivity evaluations were repeated 6 weeks postoperatively.

RESULTS

There was a statistically significant decrease in the patients with varicose veins compared with the control group in response to nitroprusside (SNP) applied at 4 mC in the supine position. Furthermore, there was also a significant difference in the response to acetylcholine (ACh) in patient group in the sitting position (P < 0.05). We also observed a statistically significant decrease in the responses to SNP applied for 1, 2, and 4 mC (P < 0.05) in the patients in the sitting position. The relief of pain and edema after surgery was found to be significant (P < 0,001). In the subgroup in which ACh was applied for 1 and 4 mC in the supine position, postoperative microvascular flow was significantly increased (P < 0.005). Moreover, based on the measurements taken in the supine position, the patients in the subgroup in which SNP was applied for 1, 2, or 4 mC exhibited significantly increased postoperative microvascular dilatation (P < 0.005).

CONCLUSIONS

Saphenous vein insufficiency impairs the endothelium-dependent vasodilatation response in the perimalleolar region, and partial recoveries in microvascular function were observed after surgical treatment.

A different way to look at varicose veins

OBJECTIVE

The development of varicose veins is commonly attributed to vessel wall degeneration. The idea that varicose veins occur because of pathological processes, however, is challenged by certain observations. For example, their high prevalence (50% or greater) in many populations makes it statistically "normal" to have varicose veins; their well-established genetic predisposition raises the possibility that this high prevalence reflects a survival benefit. One way to explain this apparent contradiction is to theorize that varicose veins are produced by the same mechanism(s) that lead to the growth and remodeling of other types of blood vessels. If so, being "good" at forming varicose veins may also predispose to being "good" at forming various types of collateral blood vessels when necessary.

METHODS

A selected literature review was conducted. Works chosen for review included those suggesting that: the process of varicose vein formation may share the same basic mechanisms as the formation of collateral veins, arteries, and lymphatic vessels; and clinical outcomes may be different between subjects with and without varicose veins.

RESULTS

Evidence suggests that subjects who are "good" at forming varicose veins may also be "good" at forming various types of collateral vessels, and they may have better overall survival (with less cardiovascular morbidity) than those without varicose veins.

CONCLUSIONS

Varicose veins may be "the price we pay" for an enhanced ability to form collateral vessels when necessary.

Minimally invasive vein therapy and treatment options for endovenous heat-induced thrombus

Radiofrequency ablation and endovenous laser therapy are types of minimally invasive techniques that have been used in the treatment of chronic venous insufficiency. In both procedures, high-intensity heat via thermal energy is produced and delivered via an endovenous catheter placed in the saphenous vein. This results in changes that therapeutically induce closure of the vein by denaturing the vessel wall with subsequent thrombus formation. Patients undergo ultrasound 48 to 72 hours postprocedure to confirm vessel occlusion and assess for possible extension of thrombus into the deep venous system. Thrombus is frequently visualized with the procedure in the tributaries, the venous dilations, and at times the saphenofemoral junction. In any other setting, thrombus at the saphenofemoral junction would warrant anticoagulation. However, the characteristics, composition, and behavior of endovenous heat-induced thrombus are different than de novo thrombosis. This postprocedure endovenous heat-induced thrombus is considered a normal consequence of the procedure and does not require traditional anticoagulation in most cases, depending on the location.