Fluid dynamics of cerebrospinal venous flow in multiple sclerosis.

Stenotic immobile valves and other malformations obstruct normal cerebrospinal venous outflow, resulting in reflux flow which combines with the normal outflow to produce standing pressure waves in the internal jugular and other cerebrospinal veins. It is hypothesized that, if the cerebrospinal venous structure between the obstruction and the deep cerebral veins is sufficiently non-compliant, the standing wave will result in bidirectional flow in the fine cerebral veins. Bidirectional flow in the fine veins, over extended periods of time, will cause disorder in the veins' endothelial morphology, and ultimately, result in the disruption of the blood-brain barrier as observed in multiple sclerosis. This physics-based analysis demonstrates a positive correlation between clinically observed MS attributes with the predicted flow patterns and venous malformations that are based on fluid dynamics principles that include venous compliance influences. The physics-based approach used in this analysis provides new insights into MS pathologies based on predicted pressure and flow patterns.

Fluid dynamics of thoracic cavity venous flow in multiple sclerosis.

This paper hypothesizes, based on fluid dynamics principles, that in multiple sclerosis (MS) non-laminar, vortex blood flow occurs in the superior vena cava (SVC) and brachiocephalic veins (BVs), particularly at junctions with their tributary veins. The physics-based analysis demonstrates that the morphology and physical attributes of the major thoracic veins, and their tributary confluent veins, together with the attributes of the flowing blood, predict transition from laminar to non-laminar flow, primarily vortex flow, at select vein curvatures and junctions. Non-laminar, vortex flow results in the development of immobile stenotic valves and intraluminal flow obstructions, particularly in the internal jugular veins (IJVs) and in the azygos vein (AV) at their confluences with the SVC or BVs. Clinical trials' observations of vascular flow show that regions of low and reversing flow are associated with endothelial malformation. The physics-based analysis predicts the growth of intraluminal flaps and septa at segments of vein curvature and flow confluences. The analysis demonstrates positive correlations between predicted and clinically observed elongation of valve leaflets and between the predicted and observed prevalence of immobile valves at various venous flow confluences. The analysis predicts the formation of sclerotic plaques at venous junctions and curvatures, in locations that are analogous to plaques in atherosclerosis. The analysis predicts that increasing venous compliance increases the laminarity of venous flow and reduces the prevalence and severity of vein malformations and plaques, a potentially significant clinical result. An over-arching observation is that the correlations between predicted phenomena and clinically observed phenomena are sufficiently positive that the physics-based approach represents a new means for understanding the relationships between venous flow in MS and clinically observed venous malformations.

Effect of valve lesion on venous valve cycle: A modified immersed finite element modeling.

The present study aimed to understand the effect of venous valve lesion on the valve cycle. A modified immersed finite element method was used to model the blood-tissue interactions in the pathological vein. The contact process between leaflets or between leaflet and sinus was evaluated using an adhesive contact method. The venous valve modeling was validated by comparing the results of the healthy valve with those of experiments and other simulations. Four valve lesions induced by the abnormal elasticity variation were considered for the unhealthy valve: fibrosis, atrophy, incomplete fibrosis, and incomplete atrophy. The opening orifice area was inversely proportional to the structural stiffness of the valve, while the transvalvular flow velocity was proportional to the structural stiffness of the valve. The stiffening of the fibrotic leaflet led to a decrease in the orifice area and a stronger jet. The leaflet and blood wall shear stress (WSS) in fibrosis was the highest. The softening of the atrophic leaflet resulted in overly soft behavior. The venous incompetence and reflux were observed in atrophy. Also, the atrophic leaflet in incomplete atrophy exhibited weak resistance to the hemodynamic action, and the valve was reluctant to be closed owing to the large rotation of the healthy leaflet. Low blood WSS and maximum leaflet WSS existed in all the cases. A less biologically favorable condition was found especially in the fibrotic leaflet, involving a higher mechanical cost. This study provided an insight into the venous valve lesion, which might help understand the valve mechanism of the diseased vein. These findings will be more useful when the biology is also understood. Thus, more biological studies are needed.

Platelets Drive Thrombus Propagation in a Hematocrit and Glycoprotein VI-Dependent Manner in an In Vitro Venous Thrombosis Model.

OBJECTIVE: The objective of this study was to measure the role of platelets and red blood cells on thrombus propagation in an in vitro model of venous valvular stasis. APPROACH AND RESULTS: A microfluidic model with dimensional similarity to human venous valves consists of a sinus distal to a sudden expansion, where for sufficiently high Reynolds numbers, 2 countercurrent vortices arise because of flow separation. The primary vortex is defined by the points of flow separation and reattachment. A secondary vortex forms in the deepest recess of the valve pocket characterized by low shear rates. An initial fibrin gel formed within the secondary vortex of a tissue factor-coated valve sinus. Platelets accumulated at the interface of the fibrin gel and the primary vortex. Red blood cells at physiological hematocrits were necessary to provide an adequate flux of platelets to support thrombus growth out of the valve sinus. A subpopulation of platelets that adhered to fibrin expose phosphatidylserine. Platelet-dependent thrombus growth was attenuated by inhibition of glycoprotein VI with a blocking Fab fragment or D-dimer. CONCLUSIONS: A 3-step process regulated by hemodynamics was necessary for robust thrombus propagation: First, immobilized tissue factor initiates coagulation and fibrin deposition within a low flow niche defined by a secondary vortex in the pocket of a model venous valve. Second, a primary vortex delivers platelets to the fibrin interface in a red blood cell-dependent manner. Third, platelets adhere to fibrin, activate through glycoprotein VI, express phosphatidylserine, and subsequently promote thrombus growth beyond the valve sinus and into the bulk flow.

A case report of cough headache with transient elevation of intracranial pressure and bilateral internal jugular vein valve incompetence: A primary or secondary headache?

Background Primary cough headache (PCH) is precipitated by coughing or the Valsalva manoeuver (VM), and its underlying pathophysiology remains unclear. Case report We report a case of recurrent cough headaches precipitated by VM with transient increase of intracranial pressure (ICP) diagnosed by measuring left sigmoid sinus pressure. Bilateral internal jugular vein valve incompetence (IJVVI) was also diagnosed by Doppler ultrasonography during a VM. Indomethacin was administered for over four months, and the headache had completely disappeared at the four-month follow-up. Conclusions Cough headache might be associated with a transient increase of ICP induced by IJVVI, which might partially explain the pathophysiology of VM-induced headache. Detecting the internal jugular vein during a VM might be used as diagnostic procedure for patients who have PCH during resting and VM. If it is necessary, monitoring the ICP could be considered.

Smooth muscle cells of human veins show an increased response to injury at valve sites.

OBJECTIVE: Venous valves are essential but are prone to injury, thrombosis, and fibrosis. We compared the behavior and gene expression of smooth muscle cells (SMCs) in the valve sinus vs nonvalve sites to elucidate biologic differences associated with vein valves. METHODS: Tissue explants of fresh human saphenous veins were prepared, and the migration of SMCs from explants of valve sinus vs nonvalve sinus areas was measured. Proliferation and death of SMCs were determined by staining for Ki67 and terminal deoxynucleotidyl transferase dUTP nick end labeling. Proliferation and migration of passaged valve vs nonvalve SMCs were determined by cell counts and using microchemotaxis chambers. Global gene expression in valve vs nonvalve intima-media was determined by RNA sequencing. RESULTS: Valve SMCs demonstrated greater proliferation in tissue explants compared with nonvalve SMCs (19.3% ± 5.4% vs 6.8% ± 2.0% Ki67-positive nuclei at 4 days, respectively; mean ± standard error of the mean, five veins; P < .05). This was also true for migration (18.2 ± 2.7 vs 7.5 ± 3.0 migrated SMCs/explant at 6 days, respectively; 24 veins, 15 explants/vein; P < .0001). Cell death was not different (39.6% ± 16.1% vs 41.5% ± 16.0% terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells, respectively, at 4 days, five veins). Cultured valve SMCs also proliferated faster than nonvalve SMCs in response to platelet-derived growth factor subunit BB (2.9 ± 0.2-fold vs 2.1 ± 0.2-fold of control, respectively; P < .001; n = 5 pairs of cells). This was also true for migration (6.5 ± 1.2-fold vs 4.4 ± 0.8-fold of control, respectively; P < .001; n = 7 pairs of cells). Blockade of fibroblast growth factor 2 (FGF2) inhibited the increased responses of valve SMCs but had no effect on nonvalve SMCs. Exogenous FGF2 increased migration of valve but not of nonvalve SMCs. Unlike in the isolated, cultured cells, blockade of FGF2 in the tissue explants did not block migration of valve or nonvalve SMCs from the explants. Thirty-seven genes were differentially expressed by valve compared with nonvalve intimal-medial tissue (11 veins). Peptide-mediated inhibition of SEMA3A, one of the differentially expressed genes, increased the number of migrated SMCs of valve but not of nonvalve explants. CONCLUSIONS: Valve compared with nonvalve SMCs have greater rates of migration and proliferation, which may in part explain the propensity for pathologic lesion formation in valves. Whereas FGF2 mediates these effects in cultured SMCs, the mediators of these stimulatory effects in the valve wall tissue remain unclear but may be among the differentially expressed genes discovered in this study. One of these genes, SEMA3A, mediates a valve-specific inhibitory effect on the injury response of valve SMCs.

Role of vessel-to-prosthesis size mismatch in venous valve performance.

BACKGROUND: Efforts to treat chronic venous insufficiency have focused on the development of prosthetic venous valves. The role of prosthetic valve-to-vessel size matching has not been determined. The purpose of this investigation was to assess the effect of size mismatching on venous valve function and to establish a mismatch limit that affects valve hemodynamic performance and venous wall stress to improve future valve designs and implants. METHODS: Flow dynamics of prosthetic venous valves were studied in vitro using a pulse duplicator flow loop. Valve performance based on flow rate and pressure measurements was determined at oversizing ratios ranging from 4.2% to 25%. Valve open area ratios at different size mismatching ratios were investigated by image analysis. Finally, a wall stress analysis was used to determine the magnitude of circumferential (hoop) stress in the venous wall at various degrees of oversizing. RESULTS: Our findings indicate that valve regurgitate volume, closing time, and pressure difference across the valve are significantly elevated at mismatch ratios greater than ∼15%. This is supported by increases in regurgitate velocity and open area relative to valves tested at near-nominal diameters. At this degree of size mismatch, the wall stress is increased by a factor of two to three times relative to physiologic pressures. CONCLUSIONS: These findings establish a relationship between valve size matching and valve hemodynamic performance, including vessel wall stress, which should be considered in future valve implants. The size of the prosthetic valve should be within 15% of maximum vein size to optimize venous valve hemodynamic performance and to minimize the hoop wall stress.

[Minimally invasive method of correction of valvular insufficiency of the femoral vein in various causes of its origin genesis].

Presented herein are the results of treatment of patients with chronic venous insufficiency and trophic ulcers of lower limbs on the background of varicose disease and postthrombophlebitic syndrome. The treatment consisted in removal of pathological deep vertical venous reflux by means of a modified method of dosed narrowing of the femoral vein according to P.G. Shvalb's technique [1]. The obtained outcomes confirmed the necessity of influencing the pathological vertical deep venous reflux in patients with severe forms of chronic venous insufficiency and pronounced retrograde shunt along deep veins.

Deep venous thrombosis and postthrombotic syndrome: invasive management.

Invasive management of postthrombotic syndrome encompasses the two ends of the deep vein thrombosis spectrum, patients with acute iliofemoral deep vein thrombosis and those with chronic postthrombotic iliofemoral venous obstruction. Of all patients with acute deep vein thrombosis, those with involvement of the iliofemoral segments have the most severe chronic postthrombotic morbidity. Catheter-based techniques now permit percutaneous treatment to eliminate thrombus, restore patency, potentially maintain valvular function, and improve quality of life. Randomized trial data support an initial treatment strategy of thrombus removal. Failure to eliminate acute thrombus from the iliofemoral system leads to chronic postthrombotic obstruction of venous outflow. Debilitating chronic postthrombotic symptoms of the long-standing obstruction of venous outflow can be reduced by restoring unobstructed venous drainage from the profunda femoris vein to the vena cava.

P-selectin inhibition therapeutically promotes thrombus resolution and prevents vein wall fibrosis better than enoxaparin and an inhibitor to von Willebrand factor.

OBJECTIVE: Aptamers are oligonucleotides targeting protein-protein interactions with pharmacokinetic profiles and activity reversal options. Although P-selectin and von Willebrand factor (vWF) have been implicated in the development of venous thrombosis (VT), no studies have directly compared aptamer efficacy with standard of care in VT. In this study, ARC5692, an anti-P-selectin aptamer, and ARC15105, an anti-vWF aptamer, were compared with low-molecular-weight heparin, enoxaparin, to test the efficacy of P-selectin or vWF inhibition in promoting thrombus resolution and preventing vein wall fibrosis, in a baboon model of VT. APPROACH AND RESULTS: Groups were as follows: treatment arm: animals received P-selectin or vWF aptamer inhibitors or enoxaparin (n=3 per group). Controls received no treatment (n=3). Prophylactic arm: animals received P-selectin inhibitor (n=4) or vWF inhibitor (n=3). Treatment arm: P-selectin-inhibitor demonstrated a significant improvement in vein recanalization by magnetic resonance venography (73% at day 21), and significantly decreased vein wall collagen, compared with all groups. Anti-P-selectin equaled enoxaparin in maintaining valve competency by ultrasound. All control animals had compromised valve competency post thrombosis. Prophylactic arm: animals receiving P-selectin and vWF inhibitors demonstrated improved vein recanalization by magnetic resonance venography versus controls (80% and 85%, respectively, at day 21). Anti-P-selectin protected iliac valve function better than anti-vWF, and both improved valve function versus controls. No adverse bleeding events were observed. CONCLUSIONS: The P-selectin inhibitor aptamer promoted iliac vein recanalization, preserved valve competency, and decreased vein wall fibrosis. The results of this work suggest that P-selectin inhibition maybe an ideal target in the treatment and prophylaxis of deep VT, warranting clinical trials.

More great saphenous vein valves - less varicose veins?

BACKGROUND: In patients with chronic venous disease (CVD) the number of venous valves and the degree of valve deterioration have not been extensively investigated and are poorly understood. The aim of this prospective study was to quantitatively and qualitatively investigate the venous valves in CVD patients in view of their clinical classification. PATIENTS AND METHODS: Within two years a consecutive series of 152 patients (223 limbs) undergoing primary surgery for great saphenous vein varicose veins was investigated. In all patients the 'C' class according to the basic CEAP-classification was registered preoperatively (C2 to C6) for each limb. Both the quantity and quality of venous valves were assessed in the GSV's after removal. Qualitative evaluation of the valves was based on macroscopic appearance using a classification from 0 to 5 and described as 'valve disease class'. RESULTS: A negative correlation between age and the number of valves was detected (p = 0.0035). There was an increase of C-class with increasing age. No significant correlation between the average number of valves per meter and the C-class was detected. For all C-classes an average of between four and five valves per meter was counted. Valve disease class was positively correlated with the C-class although the valve disease class was never higher than the C-class (p < 0.05). CONCLUSIONS: The valve disease class of the great saphenous vein correlates with the C-class of the CEAP-classification. The number of valves did not correlate with the 'C'-class. With each increase in the CEAP class the age increased as well.

[Restoration of valvular function of deep veins in lower-limb varicose disease].

The present work was based on analysing the results of a complex examination and surgical treatment of 16-to-78-year-old patients presenting with varicose disease during the period from 2006 to 2010. A total of 1,095 limbs were examined and operated on in 1,070 patients. Of these, 298 (29.6 %) were men, and 709 (70.4 %) women. The distribution of the patients according to the CEAP clinical classification was as follows: C1 - 3 patients, C2 - 215, C3 - 566, C4 - 203, C5 - 29, and C6 - 79 subjects. All patients underwent ultrasonic duplex scanning, with retrograde phlebography performed in 21 cases. 51.2% of patients were diagnosed as having pathological deep venous reflux. In the group of patients with valvular insufficiency of deep veins, a total of 93 operations aimed at correcting deep reflux were performed, including 12 interventions for congenital avalvulation of veins. The indications for restorative operations on the valvular apparatus of deep veins were determined in severe forms of chronic venous insufficiency combined with axial reflux along deep veins in cases of inefficiency of conventional methods of surgical and conservative treatment. The long-term outcomes of surgery were assessed after 18-48 months. The results were evaluated by means of clinical and instrumental methods of examination: the disease severity scale, patients quality of life questionnaire, ultrasonographic and roentgen contrast methods of examination, and legometry. The operations aimed at restoring the valvular function of the femoral veins turned out to be effective methods of correcting venous reflux and made it possible to restore the valvular function in 84% of cases. In the remote postoperative period valvular competence was observed in 74.6% of patients. Carrying out such operations significantly improve the course of the disease due to decreasing the malleolar volume (p<0.001), manifestations of symptoms of chronic venous insufficiency (p<0.001), and improving quality of life (p<0.001).

[Ten years of endovenous ablation - achievements, failures and future]. / Deset let endovenózní ablace varixu, úspechy, neúspechy a budoucnost.

Endovenous ablation of varicose veins is a very frequent treatment method which has more or less replaced the classic stripping method. It has its limitations, advantages as well as disadvantages. The authors present a summarizing article and their own experience with these methods. Histology examinations performed prove differences in the reaction of the endothelium to the individual types of endovenous therapy. Causes of varicose veins treatment failures are discussed.

Caracterización de la insuficiencia venosa crónica profunda por reflujo valvular / Characterization of chronic deep venous insufficiency produced by valve reflux

Las enfermedades venosas de los miembros inferiores se describen desde épocas muy antiguas, todavía en la actualidad repercute en los pacientes de forma frecuente causando un importante impacto socioeconómico.Objetivo: caracterización de la insuficiencia venosa crónica profunda por reflujo valvular.Método: se realizó un estudio descriptivo y longitudinal con todos los pacientes atendidos en consulta de angiología con el diagnóstico de insuficiencia venosa crónica profunda, en el Hospital Provincial Universitario Docente Manuel Ascunce Domenech de Camagüey, desde marzo de 2012 a junio de 2013. El universo estuvo constituido por 60 pacientes, se aplicó un muestreo no probabilístico, que reunió los criterios de inclusión y exclusión establecidos. La información obtenida se procesó mediante programa estadístico SPSS-11,5 para Windows y estadística descriptiva para obtener distribuciones de frecuencias y por cientos. Los resultados del estudio se expusieron en tablas.Resultado: se encontró que el mayor número correspondió al sexo femenino y predominó el intervalo de 46 a 55 años. Se pudo detectar que predominaron los antecedentes patológicos familiares de insuficiencia venosa crónica, seguido del estreñimiento crónico, la obesidad- sedentarismo, antecedentes patológicos personales de trombosis venosa profunda y la multipariedad. El mayor número de casos según clasificación clínica se encontraron en los estadios cuatro y tres.Conclusiones: la insuficiencia venosa crónica es una enfermedad progresiva con una alta morbilidad y gran repercusión socio-económica. Conocer sus factores predisponentes así como sus formas de presentación, ayuda a prevenir y evitar sus estadios avanzados y mejorar la calidad de vida de estos pacientes...

Venous diseases of the lower extremities have been described since ancient times; at present, they still frequently have an effect in patients and cause an important socioeconomic impact.Objective: to characterize the chronic deep venous insufficiency produced by valve reflux.Method: a descriptive, longitudinal study was carried out to all the patients that assisted to the consultation of angiology with the diagnosis of chronic deep venous insufficiency at Manuel Ascunce Domenech University Provincial Hospital of Camagüey, from March, 2012 to June, 2013. The universe was composed of 60 patients. A non-probabilistic sampling, including the established inclusion and exclusion criteria, was applied. The information obtained was processed through the statistical program SPSS-11.5 for Windows and through descriptive statistics to obtain distributions of frequencies and percents. The results of the study were presented in charts.Result: most of patients were female with 30 cases (61.2 percent)The ages between 46 and 55 years old predominated with 22 patients. Pathological family history of chronic venous insufficiency predominated with 44 cases (89.8 percent), followed by chronic constipation, obesity and sedentary lifestyle, pathological medical history of deep vein thrombosis, and multiparity. According to the clinical classification, most of cases were in stages three and four.Conclusions: chronic venous insufficiency is a progressive disease with a high morbidity and a great socioeconomic repercussion. Knowing the predisposing factors, as well as the ways of presentation of the disease, helps to prevent the advanced stages and improve the quality of life of patients...

Caracterización de la insuficiencia venosa crónica profunda por reflujo valvular / Characterization of chronic deep venous insufficiency produced by valve reflux

Fundamento: las enfermedades venosas de los miembros inferiores se describen desde épocas muy antiguas, todavía en la actualidad repercute en los pacientes de forma frecuente causando un importante impacto socioeconómico.Objetivo: caracterización de la insuficiencia venosa crónica profunda por reflujo valvular.Método: se realizó un estudio descriptivo y longitudinal con todos los pacientes atendidos en consulta de angiología con el diagnóstico de insuficiencia venosa crónica profunda, en el Hospital Provincial Universitario Docente Manuel Ascunce Domenech de Camagüey, desde marzo de 2012 a junio de 2013. El universo estuvo constituido por 60 pacientes, se aplicó un muestreo no probabilístico, que reunió los criterios de inclusión y exclusión establecidos. La información obtenida se procesó mediante programa estadístico SPSS-11,5 para Windows y estadística descriptiva para obtener distribuciones de frecuencias y por cientos. Los resultados del estudio se expusieron en tablas.Resultado: se encontró que el mayor número correspondió al sexo femenino y predominó el intervalo de 46 a 55 años. Se pudo detectar que predominaron los antecedentes patológicos familiares de insuficiencia venosa crónica, seguido del estreñimiento crónico, la obesidad- sedentarismo, antecedentes patológicos personales de trombosis venosa profunda y la multipariedad. El mayor número de casos según clasificación clínica se encontraron en los estadios cuatro y tres.Conclusiones: la insuficiencia venosa crónica es una enfermedad progresiva con una alta morbilidad y gran repercusión socio-económica. Conocer sus factores predisponentes así como sus formas de presentación, ayuda a prevenir y evitar sus estadios avanzados y mejorar la calidad de vida de estos pacientes(AU)

Background: venous diseases of the lower extremities have been described since ancient times; at present, they still frequently have an effect in patients and cause an important socioeconomic impact.Objective: to characterize the chronic deep venous insufficiency produced by valve reflux.Method: a descriptive, longitudinal study was carried out to all the patients that assisted to the consultation of angiology with the diagnosis of chronic deep venous insufficiency at Manuel Ascunce Domenech University Provincial Hospital of Camagüey, from March, 2012 to June, 2013. The universe was composed of 60 patients. A non-probabilistic sampling, including the established inclusion and exclusion criteria, was applied. The information obtained was processed through the statistical program SPSS-11.5 for Windows and through descriptive statistics to obtain distributions of frequencies and percents. The results of the study were presented in charts.Result: most of patients were female with 30 cases (61.2 percent)The ages between 46 and 55 years old predominated with 22 patients. Pathological family history of chronic venous insufficiency predominated with 44 cases (89.8 percent), followed by chronic constipation, obesity and sedentary lifestyle, pathological medical history of deep vein thrombosis, and multiparity. According to the clinical classification, most of cases were in stages three and four.Conclusions: chronic venous insufficiency is a progressive disease with a high morbidity and a great socioeconomic repercussion. Knowing the predisposing factors, as well as the ways of presentation of the disease, helps to prevent the advanced stages and improve the quality of life of patients (AU)

Update of endovenous treatment modalities for insufficient saphenous veins--a review of literature.

Lower-limb venous insufficiency resulting from saphenous vein incompetence is a common disorder, increasing with age. For decades, surgical stripping of the great saphenous vein has been the gold standard in varicose vein treatment. The desire to optimize outcomes of treatment and reduce surgical trauma has led to the development of endovenous techniques. Today, several endovenous techniques are available to ablate the saphenous vein segments with abnormal vein valve function. In this review, we discuss the techniques, mechanisms of action, outcomes, and complications of all endovenous treatment modalities for the treatment of symptomatic lower-limb varicose veins.

External valvuloplasty for subcutaneous small veins to prevent venous reflux in lymphaticovenular anastomosis for lower extremity lymphedema.

BACKGROUND: Subcutaneous ecchymosis caused by venous reflux is a preventable complication following lymphaticovenular anastomosis. The authors developed a series of operative procedures to prevent venous reflux. This is probably the first report on valvuloplasty for small subcutaneous veins (diameter, <1 mm). METHODS: A total of 165 anastomoses in 39 limbs were operated on using this novel procedure (study group). Extended vein dissection was performed to ensure inclusion of some venous valves. Venous regurgitation was assessed using a retrograde milking test. When regurgitation was observed at all peripheral branches, external valvuloplasty was performed at the small subcutaneous vein to prevent backflow. The rate of venous reflux was compared with 151 anastomoses in 34 limbs operated on using conventional procedures (control group). Moreover, the amount of volume reduction was compared between the patients with and without venous reflux. RESULTS: In the study group, the rate of regurgitation was reduced (3.0 percent) by extended vein dissection compared with that in the control group (9.9 percent), whereas the regurgitation ceased completely following external valvuloplasty (0 percent). In addition, postoperative ecchymosis was prevented completely in the study group (8.8 percent in the control group). Perioperative improvement in the lower extremity lymphedema index was significantly different between the patients with and without venous reflux (with venous reflux, 0.0706 ± 0.0742; without venous reflux, 0.0904 ± 0.0614). CONCLUSIONS: The authors' results suggest that these operative procedures could be highly effective in preventing venous reflux. Moreover, venous reflux, if not corrected, leads to worsening of the results. Excellent results were consistently achieved by preventing venous reflux. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.