Varicose Vein Wall Research Articles

Glycosaminoglycans of Normal Veins and Their Alterations in Varicose Veins and Varicose Veins Complicated by Thrombophlebitis

The aim of the study was to examine the content and molecular differentiation of glycosaminoglycans (GAGs) in the wall of varicose veins. The studied material consisted of normal, varicose veins and varicose veins complicated by thrombophlebitis collected during operations on 26 patients. In the wall of varicose veins the mean GAGs’ content as well as the content of sulphated GAGs, except heparan sulphate was increased, whereas the amount of hyaluronic acid was decreased. Furthermore, the increased quantitative ratio between sulphated and nonsulphated GAGs was demonstrated. The results indicate an evident extracellular matrix remodelling in the wall of varicose veins particularly those complicated by thrombophlebitis, that is characterised by alterations in the content and molecular differentiation of GAGs.

Smooth muscle cell modulation and cytokine overproduction in varicose veins. An in situ study.

The exact aetiology and physiopathology of varicose disorders remain unclear. The aim of the present work was to study, in situ, the morphology and composition of cellular and matrix components in varicose veins compared with control veins and to identify factors that could contribute to varicose remodelling. A combined histological, immunohistochemical, and biochemical approach was used. Longitudinal sections of varicose (n=12) and control veins (n=9) were studied to assess the organization, structure, and phenotype of smooth muscle cells; the localization of microvascular endothelial cells; the distribution of connective tissue proteins; and the localization of cytokines. These cytokines were further quantified by ELISA. Considerable heterogeneity of the varicose vein wall was observed, with a succession of hypertrophic and atrophic segments, presenting severe disorganization of the medial layer and numerous areas of intimal thickening. In hypertrophic portions, medial smooth muscle cells showed marked alterations suggesting modulation from a contractile to a proliferative and synthetic phenotype; furthermore, the number of vasa vasorum was increased. In contrast, in atrophic portions, both cellular and matrix components were decreased. TGFbeta1 (p< or =0.005) and bFGF (p< or =0.001) were increased and VEGF was not significantly modified in varicose veins when the results were expressed per mg of DNA. These results show that phenotypic modulation of smooth muscle cells, altered extracellular matrix metabolism, and angiogenesis are the main mechanisms contributing to the morphological and functional modifications of varicose remodelling. The increased expression of bFGF and TGFbeta1 by varicose vein cells may play a pivotal role in the hypertrophy of the venous wall, but the exact mechanism leading to aneurysmal dilatations remains to be elucidated.

Changes in Metalloproteinase (MMP-1, MMP-2) Expression in the Proximal Region of the Varicose Saphenous Vein Wall in Young Subjects

Objective: An evaluation of the proteoglycan perlecan, collagen I and III, and metalloproteinases MMP−1, −2, −3 and −9 was performed to explore the possible relationships between ageing, affected vein region and reactive state of the varicose vein wall. Methods: Segments of saphenous vein were obtained from healthy subjects and from those with varicose veins. The vein specimens were subdivided according to subject age (&lt;50/^50) and vein source (distal/proximal). Results: The walls of control vein specimens acquired a more collagenous appearance with age. These changes were not accompanied by significant modifications in the immunohistochemical markers used. In specimens from young patients, proximal varicose vein segments showed an increase in MMP-1, MMP-2 and MMP-9 expression. Subjects of more advanced age showed an increase in perlecan expression. Conclusion: This increase in MMPs could lead to the acceleration of the final fibrosclerotic process characteristic of the varicose vein wall.

Estrogen and progesterone receptors in normal and varicose saphenous veins

The presence of estrogen and progesterone receptors was investigated in the walls of normal and varicose veins. Cryostat sections from the saphenous veins of 29 normal individuals, and varicose and normal vein segments of 32 patients with varicose veins, were stained with anti-estrogen or anti-progesterone receptor antibodies. Nuclear stain intensity was scored by three independent observers. Receptors to both hormones were detected in the nuclear regions of the intima and media in females and males. In the adventitia, estrogen and the progesterone receptors were found only in nuclei of the vasa vasorum. Estrogen receptor levels were lower in non-varicose segments of varicose veins compared with normal veins. In varicose segments, estrogen receptors were more abundant than in the non-varicose parts of the same vein, especially in females. Similarly, progesterone receptor levels in the non-varicose portions were higher in females. These gender differences may be related to hormonal action. However, these differences may also be age related. These findings may be related to the involvement of sex-hormones in varicosis, by mechanisms as yet unknown.

Estrogen and Progesterone Receptors in Normal and Varicose Saphenous Veins

The presence of estrogen and progesterone receptors was investigated in the walls of normal and varicose veins. Cryostat sections from the saphenous veins of 29 normal individuals, and varicose and normal vein segments of 32 patients with varicose veins, were stained with anti-estrogen or anti-progesterone receptor antibodies. Nuclear stain intensity was scored by three independent observers. Receptors to both hormones were detected in the nuclear regions of the intima and media in females and males. In the adventitia, estrogen and the progesterone receptors were found only in nuclei of the vasa vasorum. Estrogen receptor levels were lower in non-varicose segments of varicose veins compared with normal veins. In varicose segments, estrogen receptors were more abundant than in the non-varicose parts of the same vein, especially in females. Similarly, progesterone receptor levels in the non-varicose portions were higher in females. These gender differences may be related to hormonal action. However, these differences may also be age related. These findings may be related to the involvement of sex-hormones in varicosis, by mechanisms as yet unknown.

Vascular remodeling in varicose veins.

The present study describes the histopathologic aspects of varicose (n=29; mean age, 52 +/- 12 years) and normal saphenous veins (n=17; mean age, 51 +/- 12 years) of patients from a similar age group. We focused on the changes that occur in the circular layer of the venous wall. We examined the venous walls by light microscopy and transmission electronmicroscopy. A semiquantitative grading system was used to assess the smooth muscle cell (SMC) hypertrophy and the change that occurs in the elastin pattern. The volume densities (Vv) of SMC and collagen were measured as well as the diameter of the SMC, and the nuclei of SMC per fixed area were counted. The varicose vein wall differed from the normal saphenous vein by the presence of hypertrophic SMC as well as disorganized elastin patterns. A correlation between the hypertrophic SMC and an abnormal elastin pattern was observed (r=0.658, p<0.001). Ultrastructurally, the SMC show prominent microherniations and vesicles that bud from the cell. These vesicles contain microfilaments and microtubuli, although no other organelles could be detected. The elastin fibers are disrupted from the hypertrophic SMC. No significant difference could be detected in both the Vv of SMC and the Vv of collagen. The diameter of the SMC in the varicose vein (d=9.45 +/- 1.22 microm) differs significantly from that in the normal saphenous vein (d=6.22 +/- 1.47 microm) (p<0.001). Also, the nuclei of SMC per fixed area differs significantly between the varicose (87 +/- 18) and nonvaricose (117 +/- 24) veins (p<0.001). We conclude that the cellular hypertrophy of the SMC and the microherniations could be the basis for disruption of the elastin fibers connected to the SMC in varicose veins. Disrupted connections between SMC and elastin fibers could in turn induce the weakness of the venous wall observed in varicose vein disease.

Plasma endothelin-1 release in normal and varicose saphenous veins.

The aim of the study was to investigate the release of endothelin-1 (ET-1) in normal and varicose saphenous veins at baseline and after venous stasis test. Ten patients (eight women and two men, mean age 43 +/- 4) with primarily varicose great saphenous veins and ten controls (eight women and two men, mean age 42 +/- 6) were recruited. After 30 minutes of resting in supine position, venous occlusion in a leg was performed with a sphygmomanometer provided to keep the pressure in the cuff intermediate between systolic and diastolic blood pressure for 10 minutes. Blood samples were taken from the great saphenous vein just above the medial malleolus at baseline and 10 minutes after venous stasis was begun. Plasma ET-1 was determined by a radioimmunoassay system. Results are expressed as mean +/- SD. Plasma ET-1 concentration was higher in varicose than in normal saphenous veins (4 +/- 0.1 pmol/L vs 2.6 +/- 0.1 pmol/L, P < 0.001), and it significantly increased (P < 0.001) in both groups after venous stasis when compared with baseline (6.8 +/- 0.9 pmol/L and 3.6 +/- 0.1 pmol/L in varicose and normal saphenous veins, respectively). Absolute increase in plasma ET-1 was significantly greater in varicose than in normal saphenous veins (2.8 +/- 0.9 pmol/L vs 1.0 +/- 0.2 pmol/L, P < 0.01). In conclusion, increased local ET-1 release in varicose saphenous veins could be a marker for venous endothelial activation/damage and/or contribute to promote the morphologic alterations of the varicose vein wall by stimulating smooth muscle cell proliferation. On the other hand, increased ET-1 release could contribute to counterbalancing the varicose venous relaxation and to increasing preload in varicose patients via ET-1-induced venoconstriction.

Laser Doppler Flux in Normal and Varicose Long Saphenous Vein Wall

Objective: To assess the wall perfusion in normal and varicose veins. Design: Observational study. Setting: Departments of vascular surgery of private and public hospitals. Patients: Twenty-seven patients undergoing vein surgery (43 long saphenous veins) and eight controls operated on for femoral-popliteal bypass. Methods: Laser Doppler flowmetry assessing long saphenous vein wall perfusion 3 cm below the saphenofemoral junction. Results: Significantly reduced wall perfusion was shown in varicose long saphenous veins compared with normal veins: 16.3 (SD 10.3) versus 45.4 (SD 14.9); p&lt;0.001. Conclusion: Our data suggest a primary or secondary role for lower perfusion within the vein wall in varicose veins.

Increased mast cell infiltration in varicose veins of the lower limbs: A possible role in the development of varices

This study shows increased infiltration of mast cells in the walls of varicose veins in the lower limbs as an explanation of the pathogenesis of varix formation. Great saphenous veins exhibiting varicosity were histologically examined after vein stripping surgery, and the numbers of mast cells in the varicose lesions were estimated in 20 high-power fields (x400). Normal-looking regions of the veins were referred to as controls, and normal saphenous veins were prepared during coronary artery bypass grafting and designated baseline controls. The varicose lesions showed a greater extent of mast cell infiltration (15.0 +/- 8.4 cells; mean +/- standard deviation), whereas control veins (5.9 +/- 4.0) and baseline control veins (4.4 +/-2.9) had a smaller number of mast cells. The study suggests that increased mast cell infiltration contributes to the development of varicose veins.

Biochemical Assay of Collagen and Elastin in the Normal and Varicose Vein Wall

Alterations of the connective tissue in the varicose vein wall have been noted by several investigators; however, the cause of the vein dilatation has still not been established. The aim of this study was to find a biochemical explanation to the development of varices by evaluating sensitive biochemical markers of collagen and elastin in the varicose vein wall. 4-L-Hydroxyproline (HYP), as a marker of collagen content, and desmosine (DES) and isodesmosine (IDES), as markers of elastin, were measured in 47 macroscopically dilated and 32 nondilated segments of 20 varicose saphenous veins collected from 20 patients with varices. The same measurements were made in 24 fragments of normal saphenous veins collected from 14 patients in whom the vein was removed to be used for graft procedures. HYP (collagen) and DES and IDES (elastin) were determined with a colorimetric method and HPLC, respectively. ANOVA test was used to compare mean values (±SD). HYP and collagen content were similar in varicose and normal veins. There was a significant reduction of both DES and IDES in dilated segments of varicose veins (P< 0.05 vs normal veins and nondilated segments); the ratio of elastin to collagen was lower in varicose than normal veins (P< 0.05), and this reduction was most significant in the dilated segments (P< 0.01 vs normal veins). These results suggest that dilatation of the varicose vein wall may be related to some defect of elastin metabolism. Further studies on the metabolic activity of vein muscle cells are required.

Oxygen-Derived Free Radicals as Mediators of Varicose Vein Wall Damage

Varicose saphenous vein segments, segments of those veins with thrombophlebitis, and segments of normal veins obtained during operation on 23 patients were studied to define the pattern of pro-oxidative and antioxidative systems in these tissues. In segments of varicose veins (VV) the activity of superoxide dismutase (SOD) was significantly decreased as compared with normal veins: 7.8 ±2.9 vs 13.5 ±4.3 U/mg of protein (P &lt; 0.05), but it was almost unchanged in the segments of W with thrombophlebitis. The activity of glutathione reductase (GSH-R) in all studied segments was similar and amounted to about 12.0 IU. The content of free sulfhydryl (SH) groups, the concentration of ascorbic acid, and thiobarbituric acid-reactive substances (TBA-RS) in segments of VV were significantly decreased by 40%, 48%, and 47%, respectively (P &lt; 0.05) as compared with segments of normal veins. The values of ascorbic acid and TBA-RS in the segments of W with thrombophlebitis were increased by 13% and 16%, respectively, as compared with segments of normal veins. Decreased activities of SOD and reduced levels of free SH-groups and of ascorbic acid concentration in W may indicate impaired antioxidant mechanisms in this tissue.

A Comparison of the Histochemical Enzyme Pattern in Normal and Varicose Veins

In order to study enzyme activity in the walls of healthy and diseased veins, sections were taken from the stripped varicose long saphenous veins of eight patients. These were subjected to histochemical enzyme investigations. These methods were used to determine levels and localization of lactate dehydrogenase, alkaline phosphatase, adenosine triphosphatase and the lysosomal enzymes, β-glucuronidase, non-specific esterases and acid phosphatase. The method and our findings are described. The results of these histochemical investigations demonstrate an increase in lysosomal enzyme activity in the walls of varicose veins as compared to that of normal veins. This increase is greater in the media than in the intima. Enzymes responsible for energy metabolism demonstrated contradictory behaviour, with decline in the activity of such enzymes in the walls of varicose veins. This decline in enzyme activity was more marked in the intima than in the media and was especially noticeable in the histochemical demonstration of Ca++-adenosine triphosphatase.

Ultrastructural evidence for collagen degradation in the walls of varicose veins

In the myointimal thickening of human varicose veins morphologically distinct collagen fibrils within the cytoplasm of intimal smooth muscle cells (SMC) were observed, which could be interpreted as a possible image of collagen phagocytosis. Human varicose veins were obtained surgically from five patients and studied both histologically and electronmicroscopically. A myointimal thickening of a different degree was established in all cases examined. In three cases a large number of intimal SMC displayed intracellular membrane-bound collagen-like fibrils. The fibrils were single or packed together in small groups, showed the typical periodicity of collagen, and were surrounded by an ill-defined homogeneous “matrix” material. Within other SMC cytoplasmic vacuoles were found, including collagen fibrils in a more advanced stage of lysosomal decomposition. Characteristically the collagen-containing intimal SMC were localized predominantly in close proximity to newly formed capillaries of the thickened intima, where a relatively great quantity of bloodborne monocytes was also observed. It is suggested that vascular SMC are capable of phagocytosis and decomposition of collagen. Thus they may be part of the cellular basis for collagen breakdown in the remodeling of the blood vessel wall.

Cathepsin D activity and protein degradation products content in the walls of varicose veins of the lower limbs.

Cathepsin D activity and the content of proteins and acid-soluble tyrosine in the walls of varicose veins, thrombophlebitic varicose veins and normal saphenous veins were determined. It was found that the cathepsin D activity in the wall of varicose veins is almost 1.5 times as high as that activity in a thrombophlebitic varicose vein wall and more than 3 times higher than in the wall of a normal vein. The acid-soluble tyrosine content of the varicose vein was slightly higher than that of the normal vein, whereas the content of the thrombophlebitic varicose vein was more than 1.5 times as high as that of the normal vein. Cathepsin D has a destructive effect on the varicose vein wall and accelerates the removal of thrombi in varicophlebitis.

Enzymes in the wall of normal and varicose veins. Histochemical study.

An examination was made of 10 samples of the great saphenous vein, removed from persons without varices and serving as the control group. A further 20 samples of typical varices, as well as 20 samples of normal veins obtained from persons with varices, were examined. The venous walls were tested for activities of certain hydrolytic enzymes and dehydrogenase systems. In both the varicose veins and the normal veins obtained from persons with varices it was found that structural changes occur and histochemical tests show a marked increase in the activity of acid phosphatase and decreased activities of malate dehydrogenase, non-specific esterase, ATPase, and 5-nucleotidase. An increased activity of the lactate dehydrogenase was found only in 55 % of the cases. In normal veins obtained from persons with varices, these changes were less pronounced. The layer of the circular muscle cells of the media is the zone of a varicose vein which sustains the heaviest damage.