***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Background Twenty subjects were treated with either polidocanol ( POL ) or sodium tetradecyl sulfate ( STS ) to compare the efficacy and adverse sequelae of each agent . Objective To determine the safety and efficacy of two widely used sclerosing agents . Methods After the exclusion of saphenofemoral junction incompetency , each subject 's leg veins were categorized by size ( < 1 , 1–3 , and 3–6 mm in diameter ) . Each leg was then r and omized to be treated with 0.5 % , 1 % , or 1 % foam of POL or 0.25 % , 0.5 % , or 0.5 % foam of STS according to vein size . An independent panel of four physicians , blinded to treatment , performed r and omized photographic evaluations obtained pretreatment and 12 weeks post-treatment . Subject satisfaction index and overall clinical improvement assessment were also obtained . Results An average 83 % improvement was noted for all vein sizes in all subjects with both POL and STS after a single treatment . Subjects were satisfied with treatment , regardless of the sclerosing agent used or the vein size treated . There was no statistically significant difference in adverse effects between each group . Conclusion Both POL and STS are safe and effective sclerosing agents in the treatment of varicose and telangiectatic leg veins . Both are very tolerable and demonstrate similar post-treatment sequelae OBJECTIVE The aim of this r and omized study was to compare a new method of endovenous saphenous vein obliteration ( Closure System , VNUS Medical Technologies , Inc , Sunnyvale , Calif ) with the conventional stripping operation in terms of short-term recovery and costs . METHODS Twenty-eight selected patients for operative treatment of primary greater saphenous vein tributary varicose veins were r and omly assigned to endovenous obliteration ( n = 15 ) or stripping operation ( n = 13 ) . Postoperative pain was daily assessed during the 1st week and on the 14th postoperative day . The length of sick leave was determined . The R AND -36 health survey was used to assess the patient health-related quality of life . The patient conditions were controlled 7 to 8 weeks after surgery , and patients underwent examination with duplex ultrasonography . The comparison of costs included both direct medical costs and costs result ing from lost of productivity of the patients . Costs that were similar in the study groups were not considered in the analysis . RESULTS All operations were successful , and the complication rates were similar in the two groups . Postoperative average pain was significantly less severe in the endovenous obliteration group as compared with the stripping group ( at rest : 0.7 , st and ard deviation [ SD ] 0.5 , versus 1.7 , SD 1.3 , P = .017 ; on st and ing : 1.3 , SD 0.7 , versus 2.6 , SD 1.9 , P = .026 ; on walking : 1.8 , SD 0.8 , versus 3.0 , SD 1.8 , P = .036 ; with t test ) . The sick leaves were significantly shorter in the endovenous obliteration group ( 6.5 days , SD 3.3 days , versus 15.6 days , SD 6.0 days ; 95 % CI , 5.4 to 12.9 ; P < .001 , with t test ) . Physical function was also restored faster in the endovenous obliteration group . The estimated annual investment costs of the closure operation were US $ 3360 . The other direct medical costs of the Closure operation were about $ 850 , and those of the conventional treatment were $ 360 . With inclusion of the value of the lost working days , the Closure treatment was cost-saving for society , and when 40 % of the patients are retired ( or 60 % of the productivity loss was included ) , the Closure procedure became cost-saving at a level of 43 operations per year . CONCLUSION Endovenous obliteration may offer advantages over the conventional stripping operation in terms of reduced postoperative pain , shorter sick leaves , and faster return to normal activities , and it appears to be cost-saving for society , especially among employed patients . Because the procedure is also associated with shorter convalescence , this new method may potentially replace conventional varicose vein surgery STUDY OBJECTIVE : To determine the prevalence of varicose veins and chronic venous insufficiency ( CVI ) in the general population . DESIGN : Cross sectional survey . SETTING : City of Edinburgh . PARTICIPANTS : Men and women aged 18 - 64 years selected r and omly from age-sex registers of 12 general practice s. MAIN RESULTS : In 1566 subjects examined , the age adjusted prevalence of trunk varices was 40 % in men and 32 % in women ( p < or = 0.01 ) . This sex difference was mostly a result of higher prevalence of mild trunk varices in men . More than 80 % of all subjects had mild hyphenweb and reticular varices . The age adjusted prevalence of CVI was 9 % in men and 7 % in women ( p < or = 0.05 ) . The prevalence of all categories of varices and of CVI increased with age ( p < or = 0.001 ) . No relation was found with social class . CONCLUSIONS : Approximately one third of men and women aged 18 - 64 years had trunk varices . In contrast with the findings in most previous studies , mainly conducted in the 1960s and 1970s , chronic venous insufficiency and mild varicose veins were more common in men than women . No evidence of bias in the study was found to account for this sex difference . Changes in lifestyle or other factors might be contributing to an alteration in the epidemiology of venous disease BACKGROUND Endovascular radiofrequency obliteration has been used as an alternative to conventional vein-stripping surgery for elimination of saphenous vein insufficiency . A clinical registry was established in 1998 , and its mid-term results have been reported previously . This study is to demonstrate the long-term treatment outcomes and to determine the risk factors that affect treatment efficacy . METHODS Data were collected in an ongoing multicenter , prospect i ve registry . Patients were treated before October 2004 .  Clinical and duplex ultrasound follow-up  was performed 1 week , 6 months , 1 year , and yearly thereafter to 5 years . Treatment efficacy and clinical improvement after the procedure were analyzed . Three types of anatomical failure were identified . Logistic regression analysis was performed to determine the existence of any significant risk factors associated with anatomical failure . Risk factors considered were age , gender , body mass index , vein diameter , and pullback speed . The impact of anatomical failure on clinical symptoms and varicose vein recurrence was also analyzed . RESULTS There were 1,006 patients ( 1,222 limbs ) treated , their mean age was 47.4 + /- 12.1 years , and 78.1 % were female . Veins treated included 89.1 % great saphenous vein above-knee segments , 1.2 % great saphenous vein below-knee segments , 4.1 % great saphenous vein groin-to-ankle , 4.3 % small saphenous veins , and 1.3 % accessory saphenous veins . Mean vein diameter was 7.5 mm , with a maximum of 24 mm . Vein occlusion rates were 87.1 % , 88.2 % , 83.5 % , 84.9 % , and 87.2 % , and reflux-free rates were 88.2 % , 88.2 % , 88.0 % , 86.6 % , and 83.8 % at each annual follow-up . Clinical symptom improvement was seen in 70 % to 80 % of limbs with anatomical failures and in 85 % to 94 % of limbs with anatomical success from 6 months to 5 years after the radiofrequency obliteration . Logistic regression analysis showed that catheter pullback speed ( P < .0001 ) and body mass index ( P < .0333 ) were risk factors for anatomical failure . Limbs that had type II and type III anatomical failures were found to be more prone to varicose vein recurrence . CONCLUSIONS Endovascular radiofrequency obliteration of saphenous vein reflux exhibits enduring efficacy . Adequate pullback speed during the procedure should be emphasized to ensure the proper thermal dose delivery . A whole treatment strategy to address hemodynamically significant tributaries and perforators can further improve treatment outcomes . Body mass index is a risk factor for anatomical failure , indicating the impact of hemodynamic factors on disease progression and recurrence AIM The innovations for disease management need to be thoroughly evaluated so that their benefits and potential downsides can be compared with the already existing approaches . Endovascular laser ( EVL ) treatment for varicose veins offers today several advantages over surgical st and ard stripping . The Italian Endovenous-laser Working Group ( IEWG ) is a homogeneous group of surgeons and phlebologists who have been using EVL since 1999 and has undertaken to examine EVL in a multicenter study starting from a well defined rationale , with the benefit of a single protocol to use . METHODS In a cooperative , multicenter , clinical study , 1076 limbs in 1050 patients , mean age of 54.5 years , 241 males and 809 females affected by chronic venous insufficiency ( CVI ) were considered eligible for surgery and stratified by CEAP classification in a four-year period ( January 1999 December 2003 ) . Inclusion criteria were insufficiency of the great and /or small saphenous vein at various levels , beyond those accessory saphenous trunks with incompetence in the saphenofemoral junction . In all cases truncular reflux apparead up on duplex scan examination , with or without associated varicosities . All the patients underwent a surgery on the basis of the clinical assessment . All the centres involved performed treatment in conformity with the Food and Drug Administration ( FDA ) vali date d procedure , using an endo-laser venous system kit with a 810 - 980 nm diode . Duplex scan was performed in all patients after 36 months with very few lost to follow-up cases . RESULTS In the immediate postoperative period the results have been impressive , with a very effective closure of incompetent great saphenous vein and the other treated varicose veins ( the early occlusion rate has been 99 % ) . Major complications have not been detected : in particular , no deep venous thrombosis ( DVT ) evaluated duplex ultrasound . The patients ' acceptability and satisfaction regarding the procedure , have been measured by means of a question naire on the quality of life , and the result was 96.7 % . After 36 months , the total occusion rate of saphenous trunks has been 97 % . CONCLUSIONS The first important Italian experience with EVL based on preoperative , perioperative and postoperative duplex control and which is also based on the patients ' satisfaction at mid/long-term has indicated some advantages over the st and ard treatment with the stripping method . In terms of reduced postoperative pain , shorter sick leave , a faster resumption of the normal activities , and , in particular , the total absence of DVT , we can conclude that EVL is a good solution for all patients with anatomic and hemodinamic patterns for saphenous vein surgery The study was planned to evaluate efficacy and costs of endovascular sclerotherapy ( ES ) in comparison with surgery and surgery associated with sclerotherapy in a prospect i ve ( 10-year follow-up ) , good- clinical - practice study . Patients with varicose veins and pure , superficial venous incompetence were included . Of the patients r and omized into the three groups 39 ( group A ) were treated with ES , 40 ( B ) with surgery + sclerotherapy , and 42 with surgery only ( C ) . Surgery consisted of ligation of the SFJ ( saphenofemoral junction ) and of incompetent veins detected with color duplex . Of the preselected 150 patients , 121 subjects entered the study ; 96 completed the 10-year follow-up ( mean age 52.6 ±6 years ; 51 men , 45 women ) . Dropouts were due to nonmedical problems . At 10 years no incompetence was observed in subjects treated with SPJ ligation ( B and C ) . In the ES group 18.8 % of the SFJs were patent and incompetent and in 43.8 % of limbs the distal ( below-knee ) venous system was still incompetent [ 16.1 % in the surgery + scle rotherapy group ( p < 0.05 ) and 36 % in the group treated with surgery only ( p < 0.05 vs B and 0.05 vs A ) ] . Color duplex of the long saphenous vein indicated atrophy or obstruc tion of a segment ( average 6.7 cm ) after SFJ ligation ( 4.2 cm after ES ) . The cost of ES was 68 % of surgery while the cost of surgery and sclerotherapy was 122 % of surgery only .  Endovascular sclerotherapy is an effective , cheaper treatment option , but surgery after 10 years is superior OBJECTIVE The purpose of this study was to investigate the possible long-term clinical advantages of stripping the long saphenous vein during routine primary varicose vein surgery . METHODS The study was design ed as a 5-year , clinical and duplex scan follow-up examination of a group of patients who were r and omized to stripping of the long saphenous vein during varicose vein surgery versus saphenofemoral ligation alone .  The study was conducted in the vascular unit of a 
    Output:
    
In the absence of large , comparative r and omized clinical trials , the minimally invasive techniques appear to be at least as effective as surgery in the treatment of lower extremity varicose veins