Venous duplex and pathologic differences in thrombus characteristics between de novo deep vein thrombi and endovenous heat-induced thrombi.

OBJECTIVE: Superficial venous reflux disease has been treated with endovenous ablation techniques for more than 15 years. Thrombi discovered in the postoperative period are referred to as endovenous heat-induced thrombi (EHIT). In spite of the few studies of the ultrasound differentiation between EHIT and deep vein thrombi (DVT), there remains a paucity of literature regarding the evaluation of ultrasound examination and pathologic differentiation. METHODS: Six Yorkshire cross swine underwent femoral vein thrombosis by suture ligation or endovenous radiofrequency ablation. At 1 week after the procedure, each femoral vein was imaged by color Duplex ultrasound and sent for histologic interpretation for differentiation between EHIT and DVT. Five blinded vascular surgery faculty, two vascular surgery fellows, and three vascular surgery residents reviewed the ultrasound images. RESULTS: Thrombi associated with radiofrequency ablation demonstrated a greater degree of hypercellular response, fibroblastic reaction, and edema (3.42 vs 2.92; 3.75 vs 2.42; 2.83 vs 1.33). Specimens harvested from the iatrogenic-induced DVT swine demonstrated a more prolific response to trichrome staining (3.42 vs 2.67). Evidence of revascularization was found in all of the EHIT specimens but in 33% of DVT specimens. On the basis of histologic findings, the pathologist predicted correct modality 92% of the time. Subgroup analysis comparing paired specimens from each swine failed to demonstrate any marked pathologic differences. Recorded ultrasound images from EHIT and DVT samples were reviewed by fellows, residents, and vascular surgery staff to determine whether clot was stationary or free-floating (n = 111; 93%), evidence of retracted or adherent vein (n = 105; 88%), and absence of color flow (n = 102; 85%). The degree of occlusion (partial vs total) and degree of distention of a visualized vein were least likely to be agreed on by reviewers (n = 95; 79% each, respectively). In subgroup (DVT vs EHIT) analyses, the percentage agreement was greatest among vascular surgery fellows (89% and 92%) compared with residents (82% and 79%) and faculty (78% and 77%). CONCLUSIONS: It is possible to differentiate the thrombus origin on pathologic examination but not clinically on ultrasound. Wide variability exists for ultrasound diagnosis of EHIT and de novo DVT. Care must be taken in evaluating post-treatment duplex scans to not assign diagnosis of EHIT when DVT may well be present and extending into the deep venous system. The modulation of collagen production in the treatment of DVT may be helpful in preventing vascular dysfunction and reducing the post-thrombotic changes. Further studies on injury after radiofrequency ablation and laser ablation are needed.

Multicenter assessment of the repeatability and reproducibility of the revised Venous Clinical Severity Score (rVCSS).

BACKGROUND: The Venous Clinical Severity Score (VCSS) was designed and validated as an objective measure of disease severity in patients with chronic venous disease (CVD). Recently, a revision of the VCSS (rVCSS) was performed to resolve ambiguity in the clinical descriptors and improve clarity and ease of use. This new revised VCSS requires validation to determine its repeatability and reproducibility in clinical evaluation of patients with varying levels of CVD. METHODS: A prospective multicenter protocol was designed to enroll patients undergoing evaluation for CVD at venous practices with experience using the original VCSS. At the time of initial evaluation, two clinicians independently assessed both lower extremities to determine the rVCSS and the CEAP clinical score. Between 1 and 6 weeks, patients returned and received repeat assessment of the rVCSS by the same two clinicians independently. Patients were excluded if any venous intervention occurred between the two separate evaluation visits. Scores were compared to determine inter- and intra-observer variability overall and within each CEAP clinical class. RESULTS: Seven centers enrolled a total of 136 limbs yielding 248 paired evaluations for interobserver variability and 258 paired evaluations for intraobserver variability. The mean interobserver rVCSS difference was 1.4 ± 1.7 and the mean intraobserver variability was 1.3 ± 1.6. Statistical assessment with weighted kappa yielded good repeatability (κ = 0.68; P < .0001) and good reproducibility (κ = 0.72; P < .000001) for the rVCSS. The rVCSS correlated well with the CEAP clinical class with significant differences between rVCSS in increasing classes. (P < .0001). CONCLUSIONS: In this multicenter evaluation, the rVCSS was demonstrated to be a reliable and reproducible instrument for documentation of the severity of symptoms in patients with lower extremity venous insufficiency.

Increasing awareness about venous disease: The American Venous Forum expands the National Venous Screening Program.

OBJECTIVE: To evaluate the results of the expanded National Venous Screening Program (NVSP) as administered by the American Venous Forum. METHODS: Eighty-three physicians across 40 states participated in screening Americans for venous disease. The NVSP instrument included demographics, venous thromboembolism (VTE) risk assessment, quality-of-life (QOL) assessment, duplex ultrasound scan for reflux and obstruction, and clinical inspection. Participants received educational materials and a report card to give their physician. RESULTS: A total of 2234 individuals underwent screening (mean, 26 people/site; range, 4-42). Demographic data observed included mean age of 60 years (range, 17-93 years); 77% female; 80% Caucasian; mean BMI of 29 (range, 11-68); 40% current or previous smoker; and 24% taking antiplatelet therapy and 4% taking warfarin. If placed in a situation conducive for VTE, 40% of participants were low risk, 22% were moderate risk, 21% were high risk, and 17% were very high risk. On a venous QOL assessment, 17% had a combined total score for all 11 questions of "very limited" or "impossible to do." Reflux or obstruction was noted in 37% and 5% of participants, respectively. CEAP class 0 to 6 was 29%, 29%, 23%, 10%, 9%, 1.5%, 0.5%, respectively. DISCUSSION: Despite a dramatic expansion in the second annual NSVP (from 17 to 83 centers), the presence of venous disease observed in a larger screened population continues to be high. The NVSP represents one pathway to increasing public awareness about venous disease.

Results of the national pilot screening program for venous disease by the American Venous Forum.

OBJECTIVE: This report describes the pilot of a free comprehensive national screening program for venous disease. METHODS: The screening process consisted of a venous thromboembolism (VTE) risk assessment, abbreviated duplex examination for venous obstruction and reflux, inspection for signs of chronic venous insufficiency (CVI), and an exit interview. Physicians coordinating the screenings were members of the American Venous Forum. RESULTS: Seventeen institutions screened 476 people (mean, 28 per site; range, 6 to 71). Mean age was 60 years (range, 40 to 91 years), with 78% women and 68% with a body mass index of > or =25. If placed in a situation conducive for VTE, 22 participants (5%) were low risk, 87 (18%) were moderate risk, 186 (39%) were high risk, and 179 (38%) were at very high risk. In 26 people (6%), one or more segments had venous obstruction, and 190 (40%) had one or more segments of venous reflux in the lower extremities. Varicose veins were present in 32%, edema without skin changes in 11%, skin changes attributable to venous disease in 8%, and healed or active venous stasis ulcer in 1.3% (CEAP classification 2, 3, 4, 5, and 6, respectively). Increasing age and increasing deep venous thrombosis risk score significantly correlated with increasing clinical classification, r = 0.09, P = .04, and r = 0.16, P = .0004, respectively. Those participants with reflux in one or more segments were significantly more likely to have a higher clinical classification compared with those with no reflux (P = .0001). CONCLUSION: The first comprehensive national screening for venous disease was performed. Participants were informed of their risk for VTE if placed in a situation conducive to VTE, screened for evidence of obstruction, reflux, and CVI, and empowered to share their results with their primary care provider.