Estudo experimental comparativo da resistência tensional da safena magna no tornozelo e na região inguinal / Experimental comparative assay of tensile resistance of greater saphenous vein from ankle and groin

Resumo Contexto A veia safena magna é usada como material de remendo em vários tipos de reconstrução arterial, incluindo no trauma e endarterectomias de carótida e femoral. Houve relatos de ruptura do remendo de safena, particularmente de veias colhidas na região do tornozelo. Há uma necessidade de medição objetiva da resistência tecidual da safena magna. Objetivos Mensurar a força tensional suportada pela veia safena magna e analisar a correlação entre resistência e diâmetro da veia. Métodos As veias foram coletadas durante operações de safenectomia por varizes dos membros inferiores. Foram analisados apenas segmentos sem refluxo. Foram analisados 10 membros de oito pacientes, com um total de 20 espécimes. Os espécimes foram submetidos a ensaio de tração em equipamento eletrônico, obtendo-se os valores de tensão máxima do material em quilogramas-força por centímetro quadrado (kgf/cm2; força máxima dividida pela área de secção transversa do segmento submetido à tração). Resultados A tensão máxima suportada pela veia safena do tornozelo variou de 74,02 a 190,10 kgf/cm2, e a tensão máxima da veia safena da crossa variou de 13,53 a 69,45 kgf/cm2 (p < 0,0001). O coeficiente de correlação de Pearson entre o diâmetro da veia distendida e a tensão máxima suportada foram iguais a -0,852 (correlação inversa moderada a forte). Conclusões A resistência tecidual da veia safena magna do tornozelo é maior do que a da crossa em mulheres submetidas a operação de varizes; há correlação negativa entre o diâmetro da veia e sua resistência tecidual nessa mesma população.

Abstract Background The great saphenous vein is used as patch material in several types of arterial reconstruction, including trauma and carotid and femoral endarterectomy. There have been reports of saphenous patch blowout, particularly of patches constructed with veins harvested from the ankle. There is a need for objective measurement of the resistance of saphenous vein tissues. Objectives To measure the tensile strength of the great saphenous vein harvested at the ankle and groin and analyze the correlation between diameter and tissue strength. Methods Venous samples were harvested during elective saphenous stripping in patients with symptomatic varicose veins. Only segments without reflux were included. Ten limbs from eight patients were studied, providing 20 samples in total. Venous segments were opened along their longitudinal axis and fitted to electronic traction assay equipment to obtain values for material maximum tension in kilograms-force per square centimeter (kgf/cm2; the maximum force resisted by the segment, divided by its cross-sectional area). Results The average maximum tension in the ankle saphenous vein group ranged from 74.02 to 190.10 kgf/cm2 and from 13.53 to 69.45 kgf/cm2 in the groin saphenous vein group (p < 0.0001). The Pearson coefficient for the correlation between vein diameter and maximum tension was -0.852 (moderate to strong inverse correlation). Conclusions Ankle saphenous vein tissue from female patients operated for varicose veins has significantly higher resistance than saphenous vein tissue from the groin and there is an inverse relation between vein diameter and resistance of tissue from the same population.

Mouse laser injury models: variations on a theme.

A confluence of technological advances in genetic manipulation and molecular-based fluorescence imaging has led to the widespread adoption of laser injury models to study hemostasis and thrombosis in mice. In all animal models of hemostasis and thrombosis, detailing the nature of experimentally induced vascular injury is paramount in enabling appropriate interpretation of experimental results. A careful appraisal of the literature shows that direct laser-induced injury can result in variable degrees of vascular damage. This review will compare and contrast models of laser injury utilized in the field, with an emphasis on the mechanism and extent of injury, the use of laser injury in different vascular beds and the molecular mechanisms regulating the response to injury. All of these topics will be discussed in the context of how distinct applications of laser injury models may be viewed as representing thrombosis and/or hemostasis.

Mouse models of hemostasis.

Hemostasis is the normal process that produces a blood clot at a site of vascular injury. Mice are widely used to study hemostasis and abnormalities of blood coagulation because their hemostatic system is similar in most respects to that of humans, and their genomes can be easily manipulated to create models of inherited human coagulation disorders. Two of the most widely used techniques for assessing hemostasis in mice are the tail bleeding time (TBT) and saphenous vein bleeding (SVB) models. Here we discuss the use of these methods in the evaluation of hemostasis, and the advantages and limits of using mice as surrogates for studying hemostasis in humans.

Gracilis tendon harvest may lead to both incisional and non-incisional saphenous nerve injuries.

PURPOSE: The purpose of this study was to map saphenous nerve injuries after gracilis tendon harvest, with the aim of contributing knowledge that makes it possible to prevent these injuries. METHODS: Twenty-two cadaver limbs were used. Three were dissected to examine fascial structures between the saphenous nerve and the gracilis tendon. In 19 limbs, the gracilis tendon was harvested according to standard operative routine. The saphenous nerve was subsequently exposed by dissection and injuries were recorded. RESULTS: A well-defined sub-sartorial fascial layer separated the saphenous nerve from the gracilis tendon. Incisional injuries involving either a medial cutaneous crural branch or the infrapatellar branch were found in 14 of the 19 cases. Non-incisional injuries affecting the sartorial branch of the saphenous nerve (to conform to most surgical literature, we use the term 'sartorial branch' to denote the continuation of the saphenous nerve after departure of the infrapatellar branch) were found in six cases located 5-8 cm proximal and posterior to the gracilis tendon insertion on tibia. The fascia separating the saphenous nerve from the gracilis tendon had been perforated in relation to all non-incisional injuries. CONCLUSIONS: Small subcutaneous branches of the saphenous nerve are at risk of injury from the incision, while the sartorial branch is at risk outside the incision area. Descriptions of the location of non-incisional injuries have not been published before and are of clinical relevance, as they can contribute to the prevention of saphenous nerve injuries during gracilis tendon harvest.

Syndesmotic Fixation With Suture Button: Neurovascular Structures at Risk: A Cadaver Study.

OBJECTIVES: The objective of this study was to describe the anatomic variations in the saphenous nerve and risk of direct injury to the saphenous nerve and greater saphenous vein during syndesmotic suture button fixation. METHODS: Under fluoroscopic guidance, syndesmotic suture buttons were placed from lateral to medial at 1, 2, and 3 cm above the tibial plafond on 10 below-knee cadaver leg specimens. The distance and position of each button from the greater saphenous vein and saphenous nerve were evaluated. RESULTS: The mean distance of the saphenous nerve to the suture buttons at 1, 2, and 3 cm were 7.1 ± 5.6, 6.5 ± 4.6, and 6.1 ± 4.2, respectively. Respective rate of nerve compression was as follows, 20% at 1 cm, 20% at 2 cm, and 10% at 3 cm. Mean distance of the greater saphenous vein from the suture buttons at 1, 2, and 3 cm was 8.6 ± 7.1, 9.1 ± 5.3, and 7.9 ± 4.9 mm, respectively. Respective rate of vein compression was 20%, 10%, and 10%. A single nerve branch was identified in 7 specimens, and 2 branches were identified in 3 specimens. CONCLUSION: There was at least one case of injury to the saphenous vein and nerve at every level of button insertion at a rate of 10% to 20%. Neurovascular injury may occur despite vigilant use of fluoroscopy and adequate surgical technique. Further investigation into the use of direct medial visualization of these high-risk structures should be done to minimize the risk. Levels of Evidence: Therapeutic, Level II: Prospective, comparative study.

Surgical Preparation Reduces Hydrogen Sulfide Released from Human Saphenous Veins in Coronary Artery Bypass Grafting.

The long-term patency rate of saphenous vein (SV) grafts is poor compared to arterial grafts. To investigate the effects of surgical preparation (distention) of SV on hydrogen sulfide (H2S) released from the endothelium, human SV segments were harvested from 43 patients during coronary artery bypass surgery (CABG). Acetylcholine (ACh) induced relaxation that was inhibited by NG-nitro-L-arginine + indomethacin and cysteine aminotransferase inhibitor aminooxyacetic acid in the normal SV. In contrast, ACh did not evoke relaxation in the distended SV (DSV). The concentration of H2S quantified by methylene blue assay in DSV was significantly lower than that in control. Transmission electron microscope and immunohistochemistry studies showed that the preparation destroyed the endothelium, smooth muscle, organelle, and vasa vasorum. We conclude that surgical preparation injures the endothelium and smooth muscle of the SV grafts and reduces H2S release from SV. These effects may contribute to the poor long-term patency of the SV graft.

Use of the autologous spiral vein graft: a two-stage iliac bypass in a potentially fatal case of pelvic trauma and contaminated tissues.

Serious problems may be encountered in arterial or venous reconstruction in cases of severe trauma and contaminated tissues. We report the use of a spiral venous graft (SVG) in a case of two-stage bypass aimed at saving first life, and then the extremity. Severe open and contaminated injury was present in the lower abdomen and pelvic region of 29-year-old woman brought to the emergency department following a traffic accident. The patient was in shock, and was taken for emergency surgery jointly with the relevant departments. Interposition bypasses with synthetic graft were performed in the first stage. The synthetic grafts were subsequently removed due to problems developing secondary to infection at subsequent follow-up, and revascularization was established with autologous grafts together with SVG. SVGs are alternative grafts in cases with contaminated tissues and requiring major vessel reconstruction. This technique can add to the therapeutic options available.

A New Perspective in Comparing Injuries Caused by Short-Duration External and Internal Forces in Saphenous Vein.

BACKGROUND: Great saphenous vein (GSV) graft failure is one of the major reasons for repeat bypass grafting. A comparison of the effects of simultaneous, short-duration, externally squeezing and internally distending forces on the same segment of ex-vivo human GSV has not yet been published, although similar studies have compared the experimental injury of different ex-vivo human veins. METHODS: Approximately 8-cm-long segments of GSV were harvested from each of the 15 patients. For each specimen, one end of the vein piece was occluded at a distance of 1 cm with an external cross-clamp for 5 min and the other end was similarly occluded at a distance of 1 cm by an endoluminal balloon. The middle sections of the veins, which were not occluded by any means, were taken as the control group. Two histologists, who were blinded to the groups, graded the hematoxylin and eosin (H&E) and Weigert-Van Gieson (WVG) stained sections semi-quantitatively and performed the histomorphometric measurements. RESULTS: The result of the histopathological evaluation of the intima layer showed that the microscopic scoring of lesions in the balloon group was significantly higher than that in the clamp and control groups (5.16 ± 1.32, 3.83 ± 0.75, and 1.00 ± 1.09, respectively; P < .001). In the adventitia layer, this level of scoring increased more in the clamp group than in the balloon and control groups (5.16 ± 1.16, 3.00 ± 0.89, and 0.16 ± 0.40, respectively, P < .001). CONCLUSION: Both the endoluminal balloon and external clamp techniques have harmful effects on the vein wall. Studying different kind of forces on different veins cannot provide us with reliable comparisons.

Application of a peripheral vein illumination device to reduce saphenous structure injury caused by screw insertion during arthroscopic ankle arthrodesis.

BACKGROUND: Arthroscopic ankle arthrodesis (AAA) is minimally invasive surgery, whereby percutaneous screw fixation is used through the medial aspect of the distal tibia to fusion the ankle, but it carries the risk of the saphenous vein and nerve injuries. The near-infrared (NIR) vascular imaging system, the VeinViewer® Flex, projects an image of the vein onto the skin, and the visualization of the vein may reduce the vein and nerve injuries. The purpose of this study is to investigate the risk of the saphenous vein injury by the percutaneous screw insertion during AAA, and to evaluate the effectiveness of the NIR vascular imaging system in the reduction of the saphenous vein injury. METHODS: Ten patients with the ankle osteoarthritis underwent AAA. Three screw insertion sites (proximal as number 1, anterior distal as number 2, and posterior distal as number 3) were marked and then the vein was depicted on the medial malleolus using the VeinViewer® Flex. The distance between the screw insertion sites and the closest vein was measured. Additionally, the pattern of the vein course on the medial aspect of the distal tibia was investigated in 32 ankles using the VeinViewer® Flex. RESULTS: The distance of number 1, 2, and 3 from the vein was 2.4 ± 1.4 mm (range from 0 to 5 mm), 6.3 ± 6.6 mm (range from 0 to 20 mm) and 3.5 ± 3.1 mm (range from 0 to 11 mm) respectively. In anterior screw insertion site, 3 of 10 cases showed just on the vein. The veins were observed at the anterior region from the center axis of the tibia more than 75% of ankles which was suspected as the greater saphenous vein with closely running of the saphenous nerve, but also other regions had the crossing vein. CONCLUSIONS: Percutaneous screw fixation during AAA runs the risk of causing the saphenous structure injury. The NIR light imaging system is beneficial in reducing the complications of saphenous structure damage in AAA.

Perforation of a Saphenous Vein Graft Anastomosed at a Y-Configuration to the Left Internal Mammary Artery.

Perforation of a saphenous vein graft (SVG) is a rare, yet dreadful complication during percutaneous coronary intervention (PCI). Perforation of a SVG arising at a Y-construction from the left internal mammary artery (LIMA) can be catastrophic since manipulations and material delivery through the single LIMA inflow can aggravate ischemia and accelerate hemodynamic collapse. Prior CABG and pericardial obliteration should not offer reassurance against tamponade, since coronary perforation in these patients may cause the development of loculated pericardial effusions, a complication associated with high mortality. Treating physicians must be alert for potential periprocedural pitfalls during PCI in post-CABG patients and these should be taken into consideration during interventional planning, procedure and follow-up.

The importance of scene photography in routine coronial practice: Results of an audit with an illustrative case of suspected suicidal fatal air embolism.

Pathologists providing a coronial autopsy service are very reliant on the information, including that concerning the body at the scene, provided prior to the post-mortem examination. This ensures the case is appropriate for a non-forensic autopsy and allows proper interpretation of the pathological and laboratory findings. We present the results of an audit of the extent and accuracy of the information provided (in terms of a set of descriptors), in relation to the body at the scene; whether just the information on the coronial autopsy request form 97a is used, or if it is supplemented with details from the police form 97 and statements from attending officers and scene witnesses. The scene photographs were then reviewed to assess the accuracy of the other information sources and their value to the reporting pathologist. The audit showed that scene photographs are undertaken surprisingly frequently (29.6%) but this was only clear from the coronial request in 22% of referrals. More information was consistently available in the police information for most of the scene descriptors. This was usually accurate, but only partially so, with an average of 19% of relevant features. Viewing the scene photographs was deemed beneficial or essential in 51% and 41.1% of cases. The value of scene photography is then illustrated in a case of suspected suicidal venous air embolism, where subsequent review of the images pointed strongly to the rapidity of death, with minimal blood loss but obvious targeting of a very large varicose saphenous vein in the upper thigh.

Blunt traumatic great saphenous vein pseudoaneurysm.

Traumatic venous pseudoaneurysm is extremely rare. Only two cases of great saphenous venous (GSV) pseudoaneurysm have been reported. We present a case in which a gradually enlarged mass occurred at the calf after local injury. It was nonpulsatile and varied in size with posture. It was initially misdiagnosed by contrast MRI. Duplex ultrasound and surgical intervention eventually identified it as a GSV pseudoaneurysm. This case demonstrates the need for physicians to consider venous pseudoaneurysm as a possible diagnosis for nonpulsatile masses in patient with traumatic history, and to use Duplex ultrasound for adequate evaluation.

Medial Structure Injury During Suture Button Insertion Using the Center-Center Technique for Syndesmotic Stabilization.

BACKGROUND: The center-center technique for syndesmosis fixation has been described as an improved and reliable technique for proper reduction of the syndesmosis during ankle fracture repair. Concurrently, the use of flexible fixation with a suture button is becoming an established means of syndesmosis stabilization. The purpose of this cadaveric study was to assess for medial structure injury during the placement of a suture button using the center-center technique for ankle syndesmosis repair at 3 insertion intervals. METHODS: Simulated open syndesmosis repair was performed on 10 cadaveric specimens. Three intervals were measured at 10 mm, 20 mm, and 30 mm proximal to the level of the distal tibial articular surface along the fibula. Proper longitudinal alignment of the center-center technique was completed under fluoroscopic guidance and was marked on the medial aspect of the tibia. The 3 intervals were drilled in the appropriate technique trajectory. The suture button was subsequently passed through each drill-hole interval. A single observer used a digital caliper to measure the distance from each suture button aperture with respect to the tibialis anterior tendon, tibialis posterior tendon, and greater saphenous vein and nerve. RESULTS: A total of 30 interval measurements (10 cadavers with 3 suture button segments each) were used for data analysis. Direct impingement on the greater saphenous vein was seen in 11 of 30 (36.6%) interval measurements. Six of the 11 (54.5%) observed saphenous structure impingement events occurred at the 10-mm drill hole. CONCLUSION: The results of the present study suggest that the use of the center-center technique for syndesmosis repair with suture button fixation risks preventable injury to the greater saphenous neurovasculature. CLINICAL RELEVANCE: To understand the medial ankle anatomy, as it pertains to insertion of flexible syndesmotic fixation in a cadaveric model, to aid in prevention of clinical iatrogenic injury.

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.

Factor XI-deficient mice exhibit increased bleeding after injury to the saphenous vein.

Essentials Factor XI (FXI) deficient mice have normal hemostasis in a tail transection model. The hemostatic capacity of FXI-/- mice was assessed in three different bleeding models. FXI-/- mice have increased saphenous vein bleeding. FXI-/- mice may be a useful experimental model to study bleeding associated with FXI deficiency. SUMMARY: Background Factor XI (FXI) is a key component of the intrinsic pathway of coagulation. It can be activated by either FXIIa or thrombin and amplifies thrombin generation during clot formation. Congenital FXI deficiency in humans (known as hemophilia C) is associated with bleeding after hemostatic challenge. However, to date there are no reports of excess bleeding in FXI-deficient mice. Objectives To determine if the absence of FXI in mice prolongs bleeding in different models. Methods We assessed the hemostatic capacity of FXI-/- mice in three different bleeding models: tail bleeding, surgical bleeding and saphenous vein bleeding. Results We found that tail bleeding and surgical bleeding of FXI-/- mice were similar to wild-type mice. However, FXI-/- mice had an impaired hemostatic capacity in the saphenous vein bleeding model compared with wild-type controls. Conclusions Our results indicate that FXI-/- mice have a mild hemostatic defect after injury to the saphenous vein but not after transection of the tail or vessels in the abdominal wall.

[A new method of endoscopic harvesting of the great saphenous vein in an open system]. / Novyi metod éndoskopicheskogo vydeleniia bol'shoi podkozhnoi veny v otkrytoi sisteme.

We examined a total of 246 patients subjected to coronary artery bypass grafting with the use of the great saphenous vein (GSV). The patients were subdivided into two groups. Group One (n=121) patients endured procurement of the great saphenous vein by a new endoscopic technique in an open system with the help of the equipment Karl Storz and electric dissector Ligasure. In Group Two (n=125) patients the vein was harvested by means of the traditional open method. In all patients we evaluated complications in the early postoperative period 13±2.5 days after the operation. The rate of relapsing angina pectoris in both Groups turned out to be low and did not differ (1.65% in Group One and 1.6% in Group Two). Patients of the both groups differed significantly by the incidence of postoperative complications on the lower limbs in the zone of procurement of the GSV (9.09% in Group One and 26.4% in Group Two, p=0.131). Group Two patients (open method of procurement of the GSV) were considerably more often found to have developed cases of lymphorrhoea, haematomas, disjunction of the sutures (21.6%) compared with Group One (endoscopic method) patients (3.3%) (p=0.167), which in 10.4% of cases required secondary surgical debridement of wounds in patients after the open harvest of the GSV. Eventually, the length of hospital stay for Group Two patients increased significantly (15 ± 4.5 days) compared with Group One patients (8±1.1 days) (p=0.361). Hence, the endoscopic method of harvesting the GSV in the open CO2 system makes it possible to obtain a good cosmetic effect on the lower limbs after the operation, to considerably decrease the complications rate, thus reducing the length of hospital stay.

Secondary venous aneurysm following intravenous drug abuse: A case report.

INTRODUCTION: Venous aneurysm (VA) is a rare condition that can be presented in both superficial and deep venous system. Secondary VAs as well as pseudoaneurysms are usually caused by external spontaneous or iatrogenic trauma. They are often misdiagnosed and inadequately treated. Complications include thrombosis, phlebitis, eventual pulmonary embolism and rupture. CASE REPORT: We presented a case of secondary VA of the great saphenous vein developed in a young addict following chronic intravenous drug application in the groin region. Aneurysm required urgent surgical treatment due to bleeding complication as it was previously misdiagnosed for hematoma (or abscess) and punctuated by a general surgeon. Complete resection of VA with successful preservation of continuity of the great saphenous vein was performed. Postoperative course was uneventful. Regular venous flow through the great saphenous vein was confirmed on control ultrasound examination. CONCLUSION: VAs are uncommon, among them secondary VA being extremely rare. In cases with a significant diameter or threatening complications surgical treatment is recommended.

Thermal Changes during Rheolytic Mechanical Thrombectomy.

PURPOSE: To characterize thermal changes induced by rheolytic thrombectomy (RT) within an ex vivo venous model and evaluate resultant changes of endothelial and vessel wall injury. MATERIALS AND METHODS: Patent human saphenous vein segments without thrombus were mounted in an ex vivo perfusion system with a temperature probe apposed to the adventitial surface. RT was performed over a guide wire to facilitate device centering. Continuous RT was performed for 4 minutes with temperature recorded every 10 seconds. Pulsed RT was performed for eight cycles of 30 seconds followed by 10 seconds of deactivation. Mean temperature increase, maximum temperature (Tmax), intimal/medial thickness, endothelial cell staining (CD31), and heat shock protein 90 (HSP90) expression were compared between untreated and RT-treated venous segments. RESULTS: Continuous RT produced a mean 7.6°C increase in temperature above baseline with mean Tmax of 44.1°C. Pulsed RT produced a mean 7.3°C increase in temperature and mean Tmax of 43.8°C. Differences in mean temperature increase (P = .66) and Tmax (P = .71) between the two groups were not statistically significant. RT-treated segments showed intima/media thinning (0.32 mm before RT and 0.18 mm after RT; P = .004) and reduction in intact endothelium (38.8% before RT and 13.8% after RT; P = .002). Staining for HSP90 showed a 3.1% increase in expression after RT (P = .31). CONCLUSIONS: RT in this venous model showed reproducible increases in vessel temperature and evidence of endothelial and vessel wall injury. Avoiding prolonged RT application to a focal vascular segment during clinical use may be beneficial.