Development of a Research Agenda for Endovascular Treatment of Venous Thromboembolism: Proceedings from a Multidisciplinary Consensus Panel

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Development of a Research Agenda for Endovascular Treatment of Venous Thromboembolism: Proceedings from a Multidisciplinary Consensus Panel Suresh Vedantham, MD, John H. Rundback, MD, Anthony J. Comerota, MD, David W. Hunter, MD, Mark H. Meissner, MD, Lawrence V. Hofmann, MD, McDonald Horne III, MD, Peter Gloviczki, MD, R. Torrance Andrews, MD, Chieh-Min Fan, MD, Keith M. Hume, MA, Samuel K. Goldhaber, MD, Victor F. Tapson, MD, Mahmood K. Razavi, MD, and Robert J. Min, MD

J Vasc Interv Radiol 2005; 16:1567–1573 Abbreviations: DVT ⫽ deep vein thrombosis, NIH ⫽ National Institutes of Health, PE ⫽ pulmonary embolism, VTE ⫽ venous thromboembolism

VENOUS thromboembolism (VTE) is a frequent cause of death, cardiopulmonary morbidity, and late limb disability (1,2). In recent years, minimally invasive endovascular methods have been used to treat deep vein thrombosis (DVT) and pulmonary embolism (PE), the two most common manifestations of VTE (3,4). Although early clinical experiences suggest that these techniques have significant potential to improve patient outcomes, there has been no coordinated effort to determine what research studies are

needed to refine these techniques and scientifically validate their long-term efficacy. To address these issues, a multidisciplinary meeting of prominent venous disease experts was convened in October 2004 by the Cooperative Alliance for Interventional Radiology Research (CAIRR), the clinical trials network of the Society of Interventional Radiology (SIR) Foundation. The purpose of the meeting was to establish a prioritized research agenda for endovascular VTE interventions that in-

From the Mallinckrodt Institute of Radiology (S.V.), Washington University School of Medicine, St. Louis, Missouri; Department of Vascular and Interventional Radiology (J.H.R.), Columbia Presbyterian Medical Center; Department of Radiology (R.J.M.), Weill Medical College of Cornell University, New York, New York; University of Michigan Jobst Vascular Center (A.J.C.), Toledo, Ohio; Department of Radiology (D.W.H.), University of Minnesota, Minneapolis; Division of Vascular Surgery (P.G.), Mayo Clinic College of Medicine, Rochester, Minnesota; School of Medicine (M.H.M.) and Department of Vascular and Interventional Radiology (R.T.A.), University of Washington, Seattle, Washington; Division of Interventional Radiology (L.V.H.), Johns Hopkins Hospital, Baltimore; National Institutes of Health (M.H.), Bethesda, Maryland; Department of Vascular Radiology (C.M.F.), Massachusetts General Hospital; Cardiovascular Division (S.Z.G.), Brigham and Women’s Hospital, Boston, Massachusetts; Boston, Massachusetts; Society of In-

terventional Radiology Foundation (K.M.H.), Fairfax, Virginia; Department of Medicine (V.F.T.), Duke University Medical Center, Durham, North Carolina; and St. Joseph Vascular Institute (M.K.R.), Orange, California. Received June 6, 2005; accepted August 18. Address correspondence to S.V., Mallinckrodt Institute of Radiology, Department of Radiology, 510 S. Kingshighway Blvd., St. Louis, MO 63110; E-mail: [email protected] The Society of Interventional Radiology Foundation received program support for the venous thromboembolism research consensus panel from AngioDynamics, Inc.; Arrow International, Inc.; Bacchus Vascular, Inc.; Bard Peripheral Vascular, Inc.; Bayer Healthcare; Cook, Inc.; Diomed, Inc.; Genentech, Inc.; and Tyco Healthcare. © SIR, 2005 DOI: 10.1097/01.RVI.0000183868.45154.57

cludes basic science/technology research, pilot clinical studies, and pivotal clinical trials. MEETING ORGANIZATION A 14-member VTE Research Consensus Panel was created from a list of leading scientists developed by the SIR DVT Research Committee. The Panel included members from interventional radiology (n ⫽ 8), vascular surgery (n ⫽ 3), hematology (n ⫽ 1), cardiology (n ⫽ 1), and pulmonary medicine (n ⫽ 1). Ten members served as primary discussants at the symposium and four members provided their perspective after the meeting’s conclusion. Representatives from the Food and Drug Administration, several National Institutes of Health (NIH) agencies, and industry were also present. Before the meeting, the discussants were given an agenda describing the structure and intent of the workshop. The meeting was structured into four parts per standard SIR Foundation process: (i) introductory presentations; (ii) moderated roundtable panel discussion with comments from industry and governmental representatives; (iii) research topic prioritization; and

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Table 1 Venous Thromboembolism: Clinical Topics (Panelists)

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29.

Topic

Score

No. of Panelists

Rank

Acute DVT trial: best medical therapy vs Best interventional clot removal method Pharmacomechanical thrombolysis study PE trial: best interventional therapy Study long-term patency of existing stents and new coated venous stents with or without adjuvant therapy Venous stents for chronic venous stasis Public awareness and education Appropriate use of retrievable and nonretrievable IVC filters Stratify results of interventional therapy by extent of clot/venous segment Develop better tools to measure venous obstruction Outpatient ambulatory DVT thrombolysis with daily pulse-spray Direct thrombin inhibitors for DVT Small pilot studies of different DVT treatment combinations Study of residual DVT at filter retrieval Hemodynamic evaluation and stenting of May-Thurner Syndrome Evaluate effect of pneumatic compression with or without anticoagulation on upregulation of endogenous fibrinolysis and treatment outcomes Develop DVT standards via consensus group: physicians and industry Stratify DVT treatment outcomes by hypercoagulability risk assessment Define reference standard with which to compare interventional treatment Heparin dosing during DVT thrombolysis Evaluate need for IVC filters during DVT interventions: study PE incidence Study incidence of pelvic venous obstruction in DVT patients with residual symptoms Pre-hospital hypercoagulability screening Non-invasive testing for proximal venous obstruction: focus on exercise-induced venous hypertension Effect of preoperative venous reflux on risk of post-operative DVT Treatment of lymphedema Validate the usefulness of surrogate outcome measures of success Economic/cost analysis of DVT treatments including mechanical thrombectomy and stents Comparison of surgical thrombectomy vs thrombolysis vs anticoagulation Effect of complete vs partial clot lysis upon clinical outcomes

81 29 23 23

9 5 5 5

1 2 3 3

22 22 22 19 18 17 16 13 9 8 7

6 6 4 5 4 5 4 3 3 2 3

5 5 5 8 9 10 11 12 13 14 15

7 7 7 6 4 3 1 1

1 1 1 2 2 1 1 1

16 16 16 19 20 21 22 22

1 0 0 0 0 0

1 0 0 0 0 0

22 25 25 25 25 25

(iv) preliminary clinical research protocol development (5). DATA COLLECTION The panelists’ comments were compiled into two lists of proposed VTE research topics, one for clinical research and the other for basic science/ technology research. A separate list of organizational suggestions was also compiled. Each panel member and audience attendee was asked to select and prioritize 11 topics from each composite list with a scoring system used in a previous SIR Foundation Research Consensus Panel (5). DATA ANALYSIS The scores assigned by the expert panelists were summed to yield a total priority score for each topic. Topics with substantially overlapping content

as judged by the Panel Chairman were merged into broader aggregate designations to avoid underestimation of related responses, and the aggregate rank score for each topic was then recalculated. The feasibility and design of a pivotal trial designed to address the single highest-priority clinical research topic were discussed in detail. The final recommendations were refined after consultation with Panel members who did not attend the meeting and review of the prioritization rankings and informal feedback obtained from the governmental and industry representatives. RESULTS: RANK ORDER PRIORITIZATION OF PARTICIPANT RESPONSES A total of 51 clinical research topics and 24 basic science/technology re-

search topics were initially proposed. After aggregate grouping, 29 clinical research topics and 16 basic science research topics were obtained. The results of the prioritization voting on the aggregate clinical VTE research topics are presented in Table 1 (expert panelists) and Table 2 (governmental and industry representatives). The highest total score was 81 points for “acute DVT trial: best medical therapy versus best interventional clot removal method.” Notably, this topic was the highest rated topic by every individual member of the expert panel and was also scored as the highest rated topic by the governmental and industry representatives. The next three clinical topic selections by the expert panelists, in order, were “pharmacomechanical thrombolysis study” (29 points), “pulmonary embolism trial: best interventional therapy” (23 points), and “study of long-term pa-

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Table 2 Venous Thromboembolism: Clinical Topics (Government/Industry) Government Topic 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29.

Acute DVT trial – best medical therapy vs best interventional clot removal method Pharmacomechanical thrombolysis study PE trial – best interventional therapy Study of long-term patency of existing stents and new coated venous stents with or without adjuvant therapy Venous stents for chronic venous stasis Public awareness and education Appropriate use of retrievable and nonretrievable IVC filters Stratify results of interventional therapy by extent of clot/venous segment Develop better tools to measure venous obstruction Outpatient ambulatory DVT thrombolysis with daily pulse-spray Direct thrombin inhibitors for DVT Small pilot studies of different DVT treatment combinations Study of residual DVT at filter retrieval Hemodynamic evaluation and stent placement in May-Thurner Syndrome Evaluate effect of pneumatic compression with or without anticoagulation on upregulation of endogenous fibrinolysis and treatment outcomes Develop DVT standards via consensus group: physicians and industry Stratify DVT treatment outcomes by hypercoagulability risk assessment Define reference standard with which to compare interventional treatment Heparin dosing during DVT thrombolysis Evaluate need for IVC filters during DVT interventions: study PE incidence Study incidence of pelvic venous obstruction in DVT with residual symptoms Pre-hospital hypercoagulability screening Noninvasive testing for proximal venous obstruction: focus on exercise-induced venous hypertension Effect of preoperative venous reflux on risk of postoperative DVT Treatment of lymphedema Validate usefulness of surrogate outcome measures of success Economic/cost analysis of DVT treatments including mechanical thrombectomy and stents Comparison of surgical thrombectomy vs thrombolysis vs anticoagulation Effect of complete vs partial clot lysis on clinical outcomes

tency of existing stents and new coated venous stents with or without adjuvant therapies” (23 points). The results of the prioritization voting on the aggregate basic science VTE research topics are presented in Table 3 (expert panelists) and Table 4 (governmental and industry representatives). The highest total score was 61 points for “animal models for DVT: anatomic and physiologic changes with DVT therapies.” The next three basic science/technology topic selections by the expert panelists, in order, were “artificial biosynthetic mechanical valves” (47 points), “develop methods to measure venous obstruction” (37 points), and “evaluation of valve function after treatment” (32 points). Six suggestions were made regarding key organizational steps that should be taken to properly advance

the proposed research initiatives. They are listed in Table 5. DISCUSSION: ADVANCING VENOUS THROMBOEMBOLISM RESEARCH The Panel identified several factors that have hindered earlier research efforts in the field of endovascular VTE interventions. First, consensus has been difficult to achieve regarding identification of VTE research priorities, partly because it is treated by physicians of widely varying subspecialty. For example, primary care physicians see many newly presenting cases of DVT and therefore tend to be primarily concerned with PE prevention. Conversely, interventional radiologists and surgeons often see cases of DVT with progressive thrombosis

Industry

Score

Rank

Score

Rank

45 15 9 13

1 2 8 4

47 18 9 5

1 4 11 20

15 6 10 3 0 6 0 9 0 0 0

2 12 6 18 19 12 19 8 19 19 19

6 17 28 10 4 7 0 15 7 1 8

18 5 2 10 21 16 27 7 15 24 13

10 0 7 0 5 0 0 0

6 19 10 19 15 19 19 19

17 3 22 0 15 0 3 1

5 22 3 27 7 27 22 24

0 5 11 6

19 15 5 12

8 9 7 15

13 12 16 7

7 5

10 15

1 6

24 18

or severe late limb sequelae and are therefore more inclined to also favor research directed at prevention of postthrombotic syndrome. Second, accrual of a statistically adequate patient sample has been hindered by two difficulties: (i) the challenges inherent in randomizing patients to undergo treatments of vastly different invasiveness, inconvenience, and resource utilization; and (ii) the perception that follow-up of many years is needed to meaningfully assess the effect of any treatment on the development or progression of chronic venous disease. These impediments to successful accrual have largely deterred industry stake holders from funding these studies. Third, the ability of any investigator to compete for research grants depends on several key factors, in-

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Table 3 Venous Thromboembolism: Basic Science Topics (Panelists) Topic 1. Animal models for DVT: anatomic and physiologic changes during DVT therapy 2. Artificial biosynthetic mechanical valves 3. Develop methods to measure venous obstruction 4. Evaluation of valve function after treatment 5. Effects of thrombus age, size, location on response to DVT therapy 6. Stents: endothelial seeding, drug impregnation 7. How does pathologic clot differ from hemostatic clot biochemically and in response to treatments? 8. Endothelial function and vein wall morphology after surgical and endovenous treatments 9. Intra-thrombus direct thrombin inhibitors 10. Anti-inflammatory effects of heparin on DVT 11. Permeability of clot to thrombolytic agents 12. Histology of stented veins (non-dialysis model) 13. Models of venous angiogenesis 14. Develop clot-avid agents to reduce bleeding 15. Etiology of venous disease 16. Develop objective criteria for relevance of anatomic disease

Score

No. of Panelists

Rank

61

9

1

47 37 32 31 27 23

9 7 6 7 5 5

2 3 4 5 6 7

23

5

7

21 20 18 14 14 11 9 6

5 4 6 4 4 3 3 2

9 10 11 12 12 14 15 16

Table 4 Venous Thromboembolism: Basic Science Topics (Government/Industry) Government

Industry

Topic

Score

Rank

Score

Rank

1. Animal models for DVT: anatomic and physiologic changes during DVT therapy 2. Artificial biosynthetic mechanical valves 3. Develop methods to measure venous obstruction 4. Evaluation of valve function after treatment 5. Effects of thrombus age, size, location on response to DVT therapy 6. Stents: endothelial seeding, drug impregnation 7. How does pathologic clot differ from hemostatic clot biochemically and in response to treatments? 8. Endothelial function and vein wall morphology after surgical and endovenous treatments 9. Intra-thrombus direct thrombin inhibitors 10. Antiinflammatory effects of heparin on DVT 11. Permeability of clot to thrombolytic agents 12. Histology of stent-implanted veins (nondialysis model) 13. Models of venous angiogenesis 14. Develop clot-avid agents to reduce bleeding 15. Etiology of venous disease 16. Develop objective criteria for relevance of anatomic disease

41 7 3 9 15 18 20

1 11 15 9 5 4 2

56 11 37 33 18 9 13

1 8 2 3 4 9 6

20

2

13

6

14 0 7 9 6 10 12 5

6 16 12 9 13 8 7 14

17 0 7 2 5 1 6 8

5 16 11 14 13 15 12 10

cluding proven expertise with the treatment modality, strong scientific background in the relevant disease process, departmental support and resources for grant development, and the direct patient access needed to effectively accrue patients. Interventional radiologists have extensive expertise with image-guided therapies including VTE treatments, but their

ability to compete for grant funding has been compromised by relative lack of focus in a single disease process, insufficient access to patients, and lack of grant development resources and clinical trials infrastructure (6,7). The CAIRR was created by the SIR Foundation with the specific intent of overcoming challenges of this kind. The first step in the CAIRR process for

any important research area is the development of a multidisciplinary Research Consensus Panel to identify and prioritize those research projects that are pivotal, feasible, translational, innovative, and strategic. The work product of each Research Consensus Panel is expected to include a White Paper summarizing the consensus strategic research agenda, an execu-

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Table 5 Venous Thromboembolism Organizational Suggestions 1. Bring together subspecialty societies to lobby for insurance coverage of patients in clinical research trials; extend policy to non-NIH research 2. Communication/collaboration with family practice, emergency medicine, and internal medicine societies regarding research efforts and include them in clinical trials process 3. Participate in government and industry initiatives for defining standards and reporting of venous interventions 4. Study cardiology and oncology models for large-scale randomized trials 5. Obtain multidisciplinary consensus to best harness available research funds 6. Review pertinent pilot data from endovascular research being done at NIH

tive protocol summary for clinical trial development, and a list of basic science and clinical research priorities to guide development of Requests for Application within the SIR Foundation and external organizations. The VTE Research Consensus Panel had broad multidisciplinary representation of venous disease specialists, although primary care physicians and emergency physicians would be valuable additions for future meetings. The possibility that different choices in panelist selection or topic grouping would have altered the priority rankings of some research topics must be considered. However, given the general concordance of the panelist, industry, and governmental rankings, it appears unlikely that these subjective decisions would have fundamentally altered the Panel’s major conclusions. Hence, the Panel is convinced that the final rankings reported in this document articulate a clear research direction. As such, they are expected to stimulate rapid progress in several areas: (i) establishment of a multidisciplinary steering committee for grant development to address the prioritized VTE research question; (ii) acquisition of Food and Drug Administration and NIH feedback early in the

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grant development process; (iii) appropriation of resources within the SIR Foundation and other organizations for VTE grant development and clinical trial execution; and (iv) development of SIR Foundation Requests for Application, NIH program announcements, and other mechanisms with which to stimulate the needed clinical and basic science research. Pivotal Clinical Study: Acute Proximal DVT The Panel overwhelmingly considers a clinical trial comparing interventional clot removal and best medical therapy versus best medical therapy alone in the treatment of acute proximal DVT to represent the most important clinical VTE research priority. Given the nature of the clinical outcomes needing study and the expected costs, the Panel is convinced that a governmental funding mechanism will be needed. Although concern was expressed that a DVT thrombolysis study might not top the research priority list of the NIH, the Panel is cautiously optimistic that such a study would be funded were its clinical importance and scientific design to be endorsed by a broad range of subspecialists. The Panel believes that the research environment for DVT has fundamentally improved in recent years. Systematic assessment of venous disease outcomes is now possible with use of a number of questionnaire instruments and scoring systems, including the American Venous Forum’s Venous Clinical Severity Score, Venous Segmental Disease Score, Venous Disability Score, and several disease-specific quality of life instruments (8,9). Major advances in noninvasive imaging of the lower-extremity veins and pulmonary arteries also enable accurate assessment of the anatomic outcomes of VTE therapies. In addition, endovascular methods of treating DVT have been refined with greater experience during the past decade, and most interventionalists are now familiar with the basic techniques of catheter-directed thrombolysis and venous stent placement. In addition, physician awareness of the impact of postthrombotic syndrome on health-related quality of life in DVT has been strengthened by



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studies that used the aforementioned venous outcome measures and economic indicators. These studies indicate that postthrombotic syndrome develops in an unacceptably high proportion of patients with DVT treated with standard therapy and often leads to disabling symptoms, venous ulcers, quality of life impairment, and major socioeconomic costs (10 –17). As a result, the impact of DVT-related morbidity and the potential value of image-guided therapies are increasingly being recognized by governmental organizations, industry, and the mass media (18,19). Hence, prevention of DVT-related morbidity has dramatically increased in prominence as a national health care priority. The rationale supporting the use of early thrombus removal for DVT is strong. Proponents cite the success of previous early thrombus removal strategies (ie, systemic thrombolysis and contemporary surgical thrombectomy) in providing better late limb outcomes in several small studies and the ability of catheter-directed thrombolysis to remove venous thrombus in a manner that is more effective than systemic thrombolysis, less invasive than surgical thrombectomy, and possibly safer than both (7,20 –23). In a recent case-control study, patients with acute iliofemoral DVT who were treated successfully with catheterdirected thrombolysis plus anticoagulation had superior health-related quality of life and reduced incidence of postthrombotic syndrome at 22 months compared with a matched cohort of patients who received anticoagulation alone (24). Two recent prospective studies, including a singlecenter randomized trial and a nonrandomized comparative cohort study, confirmed the potential of catheter-directed thrombolysis to produce improved late limb outcomes in acute DVT (25,26). Hence, SIR has indicated that catheter-directed thrombolysis is reasonable to consider for ambulatory patients with extensive acute DVT and long life expectancy who are thought to be at low risk for bleeding (27). Other subspecialists, including a consensus panel of the American College of Chest Physicians, cite the absence of any conclusively proven longterm benefit for catheter-directed thrombolysis and the increased bleeding risk for systemic thrombolysis as

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reasons why catheter-directed thrombolysis should be restricted to patients with DVT who have limb-threatening circulatory compromise (28,29). The existence of such strong disagreement among physicians regarding the firstline treatment of acute DVT, a common and potentially disabling disease, provides a compelling scientific and ethical argument in favor of pursuing a randomized clinical trial. Preclinical and Pilot Clinical Research The Panel identified a number of promising future directions for which preclinical studies and acquisition of pilot clinical data should be expedited. First, although some animal models of venous thrombosis are available, systematic evaluation of their relative advantages and disadvantages as investigative tools with which to study endovascular VTE interventions is needed. The utility of endovascular techniques in efficiently creating animal models is also worthy of study. Second, the development of new therapeutic modalities with which to treat venous disease was considered to be an essential primary research area. This included study of devices such as artificial biosynthetic mechanical valves and the testing of new pharmacologic agents to manage thrombus and to stimulate venous angiogenesis (30). Third, methods of refining treatment parameters and combining existing technologies to optimize venous disease treatment were proposed. For DVT, evaluation of several methods to improve thrombus permeability to pharmacologic thrombolytic agents was proposed, including mechanical thrombectomy devices, ultrasound energy, and pulse-spray regimens (31,32). The treatment of PE with use of endovascular methods was also considered to be an important focus of further research. Balloon fragmentation, catheter maceration, and mechanical thrombectomy devices have been used to treat PE in combination with pharmacologic thrombolysis (4). However, one experienced PE researcher indicated that pilot data supporting any single method was lacking and that he did not believe that NIH priorities were sufficiently aligned at present to permit a pivotal

study in this area. This view was supported by the prioritization voting of the governmental representatives, who ranked PE somewhat lower compared with the Panelists.

7.

Organizational Objectives The development of clinical practice standards and reporting guidelines for venous interventions are already being addressed by SIR. Incorporation of primary care physicians into clinical trial development and careful study of cardiology and oncology models for conducting pivotal cooperative clinical studies will undoubtedly be essential for future efforts to study the research questions prioritized by the Panel.

8.

9.

SUMMARY A multidisciplinary VTE Research Consensus Panel was convened to develop a prioritized research agenda for the use of endovascular techniques to treat VTE. The Panel recommended the development of a prospective randomized trial to compare endovascular thrombus removal with anticoagulant therapy for the first-line treatment of acute proximal DVT. Accordingly, this prioritized research project will be the subject of multidisciplinary grant development efforts supported by CAIRR. References 1. Lawrence PF, Gazak CE. Epidemiology of chronic venous insufficiency. In: Ballard, JL, Bergan JJ, eds. Chronic venous insufficiency: diagnosis and treatment. London: Springer-Verlag, 2000; 3–8. 2. Goldhaber SZ, Elliott CG. Acute pulmonary embolism: part I. Epidemiology, pathophysiology, and diagnosis. Circulation 2003; 198:2726–2729. 3. Semba CP, Dake MD. Iliofemoral deep venous thrombosis: aggressive therapy with catheter-directed thrombolysis. Radiology 1994; 191:487–494. 4. Fava M, Loyola S. Applications of percutaneous mechanical thrombectomy in pulmonary embolism. Tech Vasc Interv Radiol 2003; 6:53–58. 5. Rundback JH, Dorfman G, Safriel Y, et al. Development of a research agenda for interventional oncology: proceedings from an interdisciplinary consensus panel. J Vasc Interv Radiol 2004; 15:7–12. 6. Rundback JH, Wright K, McLennan G,

10.

11.

12.

13.

14. 15.

16.

17. 18.

19.

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et al. Current status of interventional radiology research: results of a CIRREF survey and implications for future research strategies. J Vasc Interv Radiol 2003; 14:1103–1110. Mewissen WM, Seabrook GR, Meissner MH, et al. Catheter-directed thrombolysis for lower extremity deep venous thrombosis: report of a national multicenter registry. Radiology 1999; 211:39–49. Rutherford RB, Padberg FT, Comerota AJ, et al. Venous outcomes assessment. In: Gloviczki P, Yao JST, eds. Handbook of venous disorders, 2nd edition: guidelines of the American Venous Forum. London: Arnold, 2001;497–508. Lamping DL, Abenhaim L, Kurz X, et al. Measuring quality of life and symptoms in chronic venous disorders of the leg: development and psychometric evaluation of the VEINESQOL/VEINES-SYM questionnaire. Qual Life Res 1998; 7:621–622. Kahn SR, M’lan CE, Lamping DL, et al, VEINES Study Group. Relationship between clinical classification of chronic venous disease and patient-reported quality of life: results from an international cohort study. J Vasc Surg 2004; 39:823–828. Delis KT, Bountouroglou D, Mansfield AO. Venous claudication in iliofemoral thrombosis: long-term effects on venous hemodynamics, clinical status, and quality of life. Ann Surg 2004; 239: 118–126. Strandness JE Jr, Langlois Y, Cramer M, et al. Long-term sequelae of acute venous thrombosis. JAMA 1983; 250: 1289–1292. Stanley JC, Barnes RW, Ernst CB. Vascular surgery in the United States: workforce issues. J Vasc Surg 1996; 23: 172–181. Gonsalves CF. Venous leg ulcers. Tech Vasc Interv Radiol 2003; 6:132– 136. Bosanquet N. Costs of venous ulcers: from maintenance therapy to investment programmes. Phlebology Suppl 1992; 1:44–46. O’Donnell TF Browse, NL, Burnand KG, Thomas ML. The socioeconomic effects of an iliofemoral venous thrombosis. J Surg Res 1977; 22 (5):483–488. Bartolo M. Socioeconomic impact of venous diseases in Italy. Phlebologie 1992; 45:423–431. Goldhaber SZ. Deep-vein thrombosis: advancing awareness to protect patient lives. White paper – Public Health Leadership Conference on Deep-Vein Thrombosis. Washington, DC: American Public Health Association, 2003. National Quality Forum, Joint Commission on Accreditation of Healthcare

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Organizations. National consensus standards for the prevention and care of deep vein thrombosis: call for steering committee nominations and technical advisory panel nominations. Available at: www.qualityforum.org/ txDVTSCTAPcallfinal12.17.04.pdf. Accessed: . Amy Lindsay in Secrets of a Chambermaid 1 20. Arnesen H, Hoiseth A, Ly B. Streptokinase or heparin in the treatment of deep vein thrombosis. Acta Med Scand 1982; 211:65–68. 21. Elliot MS, Immelman EJ, Jeffery P, et al. A comparative randomized trial of heparin versus streptokinase in the treatment of acute proximal venous thrombosis in an interim report of a prospective trial. Br J Surg 1979; 66:838–843. 22. Goldhaber SZ, Buring JE, Lipnick RJ, et al. Pooled analyses of randomized trials of streptokinase and heparin in phlebographically documented acute deep venous thrombosis. Am J Med 1984; 76:393–397.

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23. Plate G, Eklof B, Norgren L, et al. Venous thrombectomy for iliofemoral venous thrombosis–10-year results of a prospective randomized study. Eur J Vasc Endovasc Surg 1997; 14:333–343. 24. Comerota AJ, Throm RC, Mathias SD, et al. Catheter-directed thrombolysis for iliofemoral deep venous thrombosis improves health-related quality of life. J Vasc Surg 2000; 32:130–137. 25. AbuRahma AF, Perkins SE, Wulu JT, et al. Iliofemoral deep vein thrombosis: conventional therapy versus lysis and percutaneous transluminal angioplasty and stenting. Ann Surg 2001; 233:752– 760. 26. Elsharawy M, Elzayat E. Early results of thrombolysis vs anticoagulation in iliofemoral venous thrombosis: a randomised clinical trial. Eur J Vasc Endovasc Surg 2002; 24:209–214. 27. Vedantham S, Khilnani N, Min R. Deep-vein thrombosis [letter]. N Engl J Med 2004; 351:2133–2134. 28. Buller HR, Hull RD, Hyers TM, et al.

29. 30.

31.

32.



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Antithrombotic therapy for venous thromboembolic disease. The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004; 126(suppl):401S–428S. Bates SM, Ginsberg JS. Treatment of deep-vein thrombosis. N Engl J Med 2004; 351:268–277. Pavcnik D, Machan L, Uchida B, et al. Percutaneous prosthetic venous valves: current state and possible applications. Tech Vasc Interv Radiol 2003; 6:137–142. Vedantham S, Vesely TM, Sicard GA, et al. Pharmacomechanical thrombolysis and early stent placement for iliofemoral deep vein thrombosis. J Vasc Interv Radiol 2004; 15:565–574. Chang R, Cannon RO III, Chen CC, et al. Daily catheter-directed single dosing of t-PA in treatment of acute deep venous thrombosis of the lower extremity. J Vasc Interv Radiol 2001; 12: 247–252.

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