Varicose veins: loss of release of vascular endothelial growth factor and reduced plasma nitric oxide

Compression stockings attenuate the expression of proteins associated with vascular damage in human varicose veins

OBJECTIVE

The objective of this study was to analyze whether compression stocking therapy in the human varicose vein wall may change the levels of biomarkers associated with vein insufficiency.

METHODS

Dilated collateral varicose vein samples were obtained from patients showing chronic venous disease (class 2 of the Clinical, Etiology, Anatomy, and Pathophysiology classification). Before elective surgery, 12 patients underwent compression stocking therapy (for 1 month) and 9 patients did not (control group). Expression levels of biomarkers associated with endothelial functionality (nitric oxide synthase 3), inflammation (interleukin-6, interleukin-10), oxidative stress (Gp91^phox subunit of NADPH oxidase), and coagulation (factor Xa) were determined. P-selectin, an inflammatory and thrombosis-related biomarker, was also measured.

RESULTS

Compression stockings increased the content of nitric oxide synthase 3 (control, 16.48 [16.04-17.40] AU; compression, 83.71 [67.70-91.85] AU; P < .001) in the varicose vein wall that was accompanied by reduction of both interleukin-6 levels (control, 38.72 [33.48-48.52] pg/μg protein; compression, 14.49 [11.05-17.41] pg/μg protein; P = .001) and the expression of Gp91^phox subunit of NADPH oxidase (control, 63.24 [53.79-77.03] AU; compression, 36.85 [35.66-52.27] AU; P < .010). P-selectin (control, 77.37 [61.86-85.00] AU; compression, 54.31 [49.60-67.50] AU; P = .017) and factor Xa (control, 90.78 [75.02-100.00] AU; compression, 14.50 [13.77-36.20] AU; P < .001) were also reduced in the varicose vein wall of compression stocking-treated patients. However, P-selectin lost its statistical significance after adjustment by dyslipidemia.

CONCLUSIONS

In the varicose vein wall, compression stocking therapy improved the content levels of biomarkers associated with endothelial functionality, inflammation, oxidative stress, and coagulation.

Implication of the PI3K/Akt/mTOR Pathway in the Process of Incompetent Valves in Patients with Chronic Venous Insufficiency and the Relationship with Aging

Chronic venous insufficiency (CVI) is a multifactorial disease, commonly caused by valvular incompetence (clinically diagnosed by venous reflux) and venous hypertension. The incidence of these factors clearly increases with patient age, and aging is one of the risk factors involved. The activity of the PI3K/Akt/mTOR pathway is considered fundamental in vascular pathologies, and understanding its involvement would help in the development of possible therapeutic targets. This is an observational, analytical, and prospective cohort study that reviewed 110 patients with CVI scheduled to undergo stratified saphenectomy. They were distributed according to the presence (R = 81) or absence (NR = 29) of valvular incompetence (venous reflux) diagnosed clinically. Each of the groups was further divided according to age, with a cutoff point of 50 years (NR < 50 = 13, NR ≥ 50 = 16, R < 50 = 32, and R ≥ 50 = 49). The involvement of the PI3K/Akt/mTOR pathway, as well as that of HIF-1α and HIF-2α and of CD4+, CD8+, and CD19+ cells and mastocytes, was assessed. Saphenous vein tissue samples obtained during surgery were processed for RT-qPCR and immunohistochemistry. Patients with venous reflux showed a significant increase in mRNA and protein expression levels for PI3K/mTOR and HIF-1α/HIF-2α. The number of mast cells was significantly elevated in the R group. In distribution by age, PI3K/Akt/mTOR and HIF-1α were significantly higher in R < 50 patients. Furthermore, these patients had a significant increase in the number of CD4+, CD8+, and CD19+ cells and mastocytes in the saphenous vein wall. These findings provide a basis for the possible existence of changes in PI3K/Akt/mTOR pathway expression in young patients, with potential accelerated asynchronous aging that is enhanced by CVI.

Allele rs2010963 C of the VEGFA gene is associated with the decreased risk of primary varicose veins in ethnic Russians

Objective To study the association of polymorphisms rs699947, rs2010963, rs3025039 in the VEGFA gene region and rs1870377, rs2305949, rs2071559 in the VEGFR2 gene region with the risk of primary varicose veins in ethnic Russians. Methods Genotypes were determined by real-time PCR allelic discrimination. The case group consisted of 448 patients with primary varicose veins and the control group comprised 609 individuals without a history of chronic venous disease. Association was studied by logistic regression analysis. Results Allele rs2010963 C was associated with the decreased risk of varicose veins (additive model of inheritance: odds ratio = 0.73, 95% confidence interval = 0.59-0.91, P = 0.004). Conclusions Our results provide evidence that polymorphism rs2010963 located in the 5' untranslated region of the VEGFA gene can influence genetic susceptibility to primary varicose veins in Russians. Otherwise, it can be in linkage disequilibrium with another functional single nucleotide polymorphism that can alter the level of vascular endothelial growth factor A protein.

Endothelial function impairment in chronic venous insufficiency: effect of some cardiovascular protectant agents

In segments of human varicose veins, endothelial function was assessed by measuring relaxation induced by acetylcholine in noradrenaline-precontracted preparations. In addition, concentration-response curves to acetylcholine were obtained before and after incubation with the arterial endothelium protectant agents captopril, losartan, troglitazone, pravastatin, or simvastatin. The antivaricose agent escin was also tested. Mean acetylcholine-induced relaxation of varicose venous rings was about 13%, approximately one third of that reported for control saphenous veins. Concentration-response curves to acetylcholine were ''u'' shaped, the result of endothelium-mediated relaxation at low concentrations, superseded by subsequent smooth muscle contractile responses. Relaxation was enhanced by the endothelium-protecting agents and by escin, troglitazone being the least, and simvastatin the most effective. It was concluded that endothelial dysfunction is present in varicose veins, that this anomaly can be reverted by cardiovascular protecting agents, and that it can play a role in the pathogenesis and treatment of chronic venous insufficiency.

Serum concentration of procoagulant, endothelial and oxidative stress markers in early primary varicose veins

OBJECTIVE

Endothelial disorders of the veins are considered to play a role in the pathogenesis of primary varicose veins and oxidative stress is implicated in these disorders. With this aim, we investigated vascular endothelial marker levels and the effect of endothelial damage on coagulation parameters and vasodilator substances to determine metabolic markers of oxidative stress in patients with varicose veins and vascular endothelial damage caused by oxidative stress.

METHODS

We investigated the levels of malondialdehyde (MDA), protein C, protein S, fibrinogen, von Willebrand factor (vWf), tissue plasminogen activator (tPA), vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), interleukin-12 (IL-12) and nitric oxide (NO) in the blood taken from the brachial vein of 25 patients with primary varicose veins (study group) and compared the results with 25 healthy volunteers (control group). We also investigated the urinary levels of prostaglandin I2 (PGI2) in the study group and compared the results with the control group.

RESULTS

There was no statistically significant difference between the study group and the control group with respect to the plasma levels of MDA, protein C, fibrinogen, tPA, IL-6, NO and urinary levels of PGI2. But plasma levels of protein S, vWf, VEGF and IL-12 were found to be statistically significantly higher in the study group than in the control group.

CONCLUSIONS

Although the systemically measured levels of protein S, vWf, VEGF and IL-12 were found to be higher in patients of primary varicose veins, levels of protein C, fibrinogen, homocysteine and PGI2 were not found to be statistically significant. No systemic increased oxidative stress seems to be related to the early stages of chronic venous insufficiency. Further studies are warranted for understanding the role of molecules such as NO, oxidative stress parameters and cytokines.

Increased vascular endothelial growth factor in patients with cyanotic congenital heart diseases may not be normalized after a Fontan type operation

BACKGROUND

To determine the change of serum concentration of vascular endothelial growth factor (VEGF) in patients with cyanotic congenital heart disease (C-CHD).

METHODS

Patients comprised four groups: group A, 19 patients without cyanosis; group B, 24 patients with C-CHD; group C, 17 patients who had C-CHD and underwent biventricular repair; and group D, 15 patients who had single ventricle and underwent a Fontan type operation. Blood samples were obtained from upper arm veins and serum VEGF was determined. We determined correlation between serum VEGF and arterial oxygen saturation and compared levels of serum VEGF among groups. In addition, age and hemodynamic variables derived from cardiac catheterization were analyzed in terms of correlation with serum VEGF.

RESULTS

Serum VEGF significantly negatively correlated with arterial oxygen saturation (r = -0.62, p < 0.0001). Serum VEGF in B and D were significantly higher than those in A and C (median = 443 pg/mL in B and 302 pg/mL in D vs 180 pg/mL in A and 216 pg/mL in C, respectively). Serum VEGF was significantly negatively correlated with patient's age (p = 0.54, p < 0.04) in D, but significantly positively correlated with systemic venous pressure (p = 0.45, p < 0.01) in pooled data.

CONCLUSIONS

Patients with C-CHD have increased serum VEGF in parallel with the degree of cyanosis. With biventricular repair, cyanosis and serum VEGF are normalized. However, with a Fontan type operation, cyanosis disappears but serum VEGF may not be normalized because of elevated venous pressure in association with younger age.

A nondraining saphenous system is a factor of poor prognosis for long-term results in surgery of great saphenous vein recurrences

OBJECTIVE

The objective was to examine the evolution of superficial venous disease after the suppression of every principal or accessory saphenous trunk.

METHODS

To achieve this aim, the long-term results of complete ablation of saphenous trunks and varicose veins during redo surgery for recurrent great saphenous veins have been assessed. Of 170 extremities (137 patients), 4.9 years of follow-up data based on physical and ultrasound examinations were obtained for 119 extremities (100 patients).

RESULTS

No varicose veins could be observed for 27.7% of extremities. For 45.3% diffuse varicose veins without reflux between the deep and superficial system could be observed. For 26.8% varicose veins and a new reflux had developed between the deep and superficial venous system. After 5 years, recurrent varicose veins were significantly associated, before operation, with the absence of insufficient residual saphenous trunk and with the presence of diffuse varicose veins (p=0.015) and, during redo surgery, with a higher number of phlebectomy incisions (p=0.02).

CONCLUSIONS

The absence of superficial venous drainage (complete removal of varicose veins and saphenous trunk) leads to appearance of rerecurrences in the surgery of great saphenous vein recurrences, 72.3% of the cases show still new varices at the 5-year follow-up. This poor prognosis probably suggests the presence of a nondraining superficial venous system.

Primary Varicose Veins: Altered Transcription of VEGF and its Receptors (KDR, flt-1, Soluble flt-1) with Sapheno-femoral Junction Incompetence

OBJECTIVE

Loss of regulation of vascular endothelial growth factor (VEGF) production and action disturbs vascular homeostasis leading to pathology. Primary varicose veins (VVs) demonstrate aberrant production/release of VEGF. Our aim was to examine transcription of genes for VEGF (VEGF(121)/VEGF(165)) and its receptors (KDR, flt-1, s.flt-1) in VVs, in relation to underlying venous incompetence.

MATERIALS AND METHODS

Samples of varicose (n=83, 18 patients) or normal (n=14, five subjects) great saphenous vein were divided into segments, determined by anatomical position from the sapheno-femoral junction (SFJ). SFJ and segmental incompetence were determined from duplex scans. Gene transcripts were amplified by RT-PCR, analysed by scanning densitometry, and the levels of transcription determined by ratio to control gene GADPH-3 (GAP-3).

RESULTS

VEGF(121)/(165), KDR and flt-1 transcription was elevated in VVs overall (p<0.001), and in VVs with an incompetent SFJ (p<0.001), but not when the SFJ was functional; s.flt-1 was unaltered. Notably, gene transcription was unaffected by segmental position, or incompetence. Position below the SFJ correlated with increased transcription of s.flt-1 when the SFJ was incompetent (p<0.04), and s.flt-1 and VEGF(121) when the segment was incompetent (p<0.03).

CONCLUSIONS

SFJ incompetence is associated with altered transcription of VEGF and its receptors reflecting an aetiological mechanism or later stage of disease development. Altered VEGF(121) and s.flt-1 transcription may be an early event in varicogenesis.

Pathogenesis of varicose veins

BACKGROUND

varicose veins are present in up to 40% of the population. They may be associated with considerable morbidity. Around 70% of patients with chronic venous insufficiency have evidence of superficial venous incompetence on duplex imaging.

METHODS

in this publication we review the evidence available regarding the pathogenesis of varicose veins.

RESULTS

a number of theories have been suggested. The present data suggests that abnormalities in the venous endothelium and smooth muscle cells result in vein wall dilatation with secondary valvular incompetence. However, there is also evidence to support acquired venous valve failure. Congenital venous valve abnormalities have not been well studied.

CONCLUSION

further work is required on this relatively neglected topic. The use of improved imaging such as high-resolution ultrasound is likely to significantly improve our understanding of venous valve function and pathology.