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forum J AN - FEB 2 0 1 2

Randomised clinical trial comparing endovenous laser ablation, radiofrequency

ablation, foam sclerotherapy and surgical stripping for great saphenous varicose veins. page 6

Effectiveness of foam sclerotherapy for the

treatment of varicose veins

page 9


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Dr. Nick Morrison

Contributing Editor/Reviewer: Manj Gohel, MD, FRCS

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Associate Editor: Ted King, MD, FAAFP, FACPh

Effectiveness of foam sclerotherapy for the treatment of varicose veins

An Economic Evaluation of Venous Thromboembolic Prophylaxis Strategies in Critically Ill Patients at Risk of Bleeding: Review and Commentary

Contributing Editor/Reviewer: Amanda Shepherd, MD

Contributing Editor/Reviewer: Timothy K. Liem, MD FACS

Associate Editor: Sukir Sinnathamby, MD

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Associate Editor: Mark Meissner, MD

Development and validation of risk prediction algorithm (QThrombosis) to estimate future risk of venous thromboembolism: prospective cohort study

Incidence of and risk factors for iliocaval venous obstruction in patients with active or healed venous leg ulcers

Contributing Editor/Reviewer: Philip Coleridge Smnith, MD FRCS

Contributing Editor/Reviewer: Robert L. Kistner, MD

Associate Editor: Mark Forrestal, MD FACPh

jan-feb ‘12

From the Editor-in-Chief

contents

Randomised clinical trial comparing endovenous laser ablation, radiofrequency ablation, foam sclerotherapy and surgical stripping for great saphenous varicose veins

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Associate Editor: Eric Mowatt-Larssen, MD

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disclosure of interests

Name

Role

Disclosure

Stephanie Dentoni, MD

Recruitment & Retention Cmte (C), Leadership Development

Nothing to Disclose

Mark Forrestal, MD, FACPh

ACP

CoolTouch: Stockholder

Mitchel P. Goldman, MD, FACPh

Merz: Grant/Research Support, Consultant, Speakers’ Bureau; Bioniche: Consultant; STD Pharmaceudicals: Consultant; BTG: Grant/ Research Support, Consultant; New Star Lasers: Stock and/or Shareholder; Lumens: Consultant, Stock and/or Shareholder

Jean-Jerome Guex, MD, FACPh

ACP BOD, Communications Standing Committee (C), International Affairs (C), Leadership Development Standing Committee, UIP 2013 Task Force, AMA HOD Task Force

Innotech International- Investigator; Pierre Fabre: Consultant; Sigvaris: Investigator; Vascular Insights, LLC: Scientific Advisory Board; ServierEutherapie: Speaker

Lowell Kabnick, MD, FACS, FACPh

ACP BOD, Education Standing Committee (C), UIP 2013 Task Force, Exhibitor Advisory (C), Phlebology Forum, Program Development, Leadership Development

Angiodynamics: Consultant, Scientific Advisory, Stockholder; Merz: Speaker; Vascular Insights LLC: Consultant, Scientific Advisory

Neil Khilnani, MD, FACPh

ACP

Sapheon: Consultant

Ted King, MD, FAAFP, FACPh

ACPF BOD

Angiodynamics: Investigator; BTG: Investigator; Merz: Speaker, Consultant

Mark Meissner, MD

ACP

Nothing to Disclose

Eric Mowatt-Larssen, MD

CME Committee

BTG: Consultant

Nick Morrison, MD, FACS, FACPh

ACP

BTG: Principal Site Investigator; VenX: Scientific Advisory Board; Medi: Speakers Bureau

Diana Neuhardt, RVT, RPhS

ACP BOD, Member Services Standing Committee, Education Standing Committee, Public Education (C), Recruitment & Retention, UIP 2013 Task Force, CME Committee, Distance Learning, Leadership Development

Nothing to Disclose

Pauline Raymond-Martimbeau, MD, FACPh

UIP 2013 Task Force

Nothing to Disclose

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From the

Editor-in-Chief Dear Readers, In this issue of Phlebology Forum are presented a number of important contributions to the phlebologic literature. I hope the reader will find, as I do, that reading the critical analyses of reports from peer-reviewed literature presented in Phlebology Forum helps one’s own evaluation of articles. The lead article is an evaluation of what may be one of the most important randomized controlled trials thus far comparing the commonly used treatment methods for patients with superficial venous incompetence, with planned follow up out five years to be eagerly anticipated. Other subjects include more information regarding the safety and efficacy of foam sclerotherapy; an attempt to develop an algorithm useful for the evaluation of patients with venous ulcers and determining risk of proximal venous obstruction; a very cogent and practical analysis of the risk of VTE in trauma patients; and an assessment of the difficulties in identifying the risk of DVT in the general patient population. A term seen with increasing frequency in the medical literature, which may be unfamiliar to some is the acronym QALY, or quality-adjusted life years. This is a parameter used to determine the impact or “burden� of a pathophysiologic process on society in general and affected patients in particular. QALY evaluation is becoming extremely important for the determination of how resources will be allocated for various disease processes all over the world, and you can expect to see it used more and more in the medical literature. My thanks to the Associate Editorial Board for their work in selecting important articles from a variety of medical journals and their excellent choices of reviewers. And finally I am happy to report that Phlebology Forum will be available, free of charge, to anyone in the phlebologic community via the American College of Phlebology website. Nick Morrison, Editor-in-Chief

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Randomised clinical trial comparing endovenous laser ablation, radiofrequency ablation, foam sclerotherapy and surgical stripping for great saphenous varicose veins Reviewer: Manj Gohel, MD, FRCS LH Rasmussen, et al: Brit J Surg 2011; 98: 1079-87

ABSTRACT: This large randomized clinical trial was set in two private surgical centers in Denmark and 500 patients (580 legs) with great saphenous vein (GSV) reflux were randomised to surgical stripping, ultrasound guided foam sclerotherapy (UGFS), endovenous laser ablation (EVLA) or radiofrequency ablation (RFA). All treatments were performed in a treatment room using tumescent anesthesia and sedation (including surgical stripping). The primary outcome measure was GSV closure and secondary outcome measures included quality of life, cost and complications. At 1 year, GSV reflux was significantly greater in patients randomised to UGFS (16.3%), compared to the other treatment groups (5.8%, 4.8% and 4.8% in EVLA, RFA and surgical groups respectively, p<0.001). Post-intervention pain scores were lowest after UGFS and RFA, whereas time to return to normal function was greatest after surgical stripping and EVLA. Quality of life scores improved in all groups. One patient had a pulmonary embolism (after UGFS) and a second patient developed a deep vein thrombosis (after surgical stripping). The authors concluded that all treatments were efficacious, but the technical failure rate was greatest after UGFS.

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COMMENTARY: The development and rapid dissemination of endovenous treatment modalities has revolutionised the management of patients with superficial venous reflux. However, this increase in choice of treatments in addition to the paradigm shift towards â&#x20AC;&#x2DC;office-basedâ&#x20AC;&#x2122; therapy has resulted in increased confusion and uncertainty for clinicians and patients. Not only are there numerous options for treating truncal saphenous reflux, but also many choices over when and how to deal with visible varicosities and which type of anesthetic to use. A number of randomized studies have compared endovenous interventions with surgical stripping and demonstrated that endovenous therapies may be associated with quicker recovery and good technical success. However, in the absence of trials with multiple treatment arms, differentiation between endovenous modalities is difficult.

Rasmussen and colleagues1 deserve praise for being the first to complete a large randomised study including the 4 main treatment modalities currently in use for GSV reflux. In keeping with other clinical studies, UGFS was associated with the worst GSV occlusion rates.2 Interestingly however, technical failure and complication rates after surgical stripping, widely considered the most invasive treatment, were comparable to EVLA and RFA. This is an important finding, particularly as the perception of poor outcomes after surgical stripping was a major

...there is a growing trend towards patientreported outcome measures such as diseasespecific quality of life.

driving force for the development of novel minimally invasive venous interventions. In this study, surgical stripping was performed in a treatment room using tumescent anesthesia and sedation. It is likely that the evolution of endovenous therapy has resulted in technical improvements in traditional surgery, such as the use of tumescent anesthesia and intra-operative duplex ultrasound.

In this study, the primary outcome measure was technical success (GSV reflux obliteration). Although this is important, there is a growing trend towards patient-reported outcome measures such as diseasespecific quality of life. Quality of life was assessed in this study using disease specific (Aberdeen Varicose Vein Questionnaire) and generic (Short form 36) tools. Improvements were seen in all treatment arms, but no differences were identified between groups. The CLASS trial is a similar randomised trial currently recruiting

1 Rasmussen LH, Lawaetz M, Bjoern L, Vennits B, Blemings A, Eklof B. Randomized clinical trial comparing endovenous laser ablation, radiofrequency ablation, foam sclerotherapy and surgical stripping for great saphenous varicose veins. Brit J Surg 2011; 98(8): 1079-87. 2 van den Bos R, Arends L, Kockaert M, Neumann M, Nijsten T. Endovenous therapies of lower extremity varicosities: a meta-analysis. J Vasc Surg 2009; 49(1): 230-9.

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patients in the United Kingdom, comparing surgical stripping, UGFS and EVLA.3 The primary patientreported outcome measure is the disease specific Aberdeen Varicose Vein Questionnaire and generic quality of life EQ-5D and SF-36 at 6 months with power calculations resulting in a target of 1015 patients. With this in mind, it is likely that the Rasmussen study lacks the power to identify differences in quality of life between groups.

In the current era of austerity, costeffectiveness has become an outcome of great relevance. Randomized trials and health economic modelling studies have suggested that traditional surgery and endovenous treatments are cost-effective using accepted thresholds.45 In this study, a cost comparison is presented, using reimbursement data. This simplistic analysis may be a missed opportunity, as this study represented an excellent chance to conduct a robust in-trial cost utility analysis using patient level data to estimate cost per QALY and incremental cost effectiveness ratios. In a clinical field where most randomized studies report follow-up to 1-2 years, it is commendable that the authors of this study plan to report outcomes to 5 years.

Venous specialists and patients are fortunate that such a range of efficacious and versatile interventions is now available for the treatment of superficial venous reflux. New technologies and commercial interests will inevitably lead to more endovenous options in the future. This important study adds to the growing body of evidence demonstrating the efficacy of endovenous interventions. With a growing range of treatments available, each with unique advantages, researchers and clinicians should focus efforts on how to optimize patient selection and choosing the best modality, or combination of modalities for individual patients.

3 http://www.thelancet.com/protocol-reviews/09PRT-2275 4 Gohel MS, Epstein DM, Davies AH. Cost-effectiveness of traditional and endovenous treatments for varicose veins. Brit J Surg 2010; 97(12): 1815-23. 5 Michaels JA, Campbell WB, Brazier JE, Macintyre JB, Palfreyman SJ, Ratcliffe J, et al. Randomised clinical trial, observational study and assessment of cost-effectiveness of the treatment of varicose veins (REACTIV trial). Health Technol Assess 2006; 10(13): 1-196, iii-iv.

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Effectiveness of foam sclerotherapy for the treatment of varicose veins Reviewer: Amanda Shepherd, MD

COMMENTARY: This article describes a consecutive cohort of 166 patients (217 legs) who underwent endovenous foam sclerotherapy (EFS) between 2004 and 2007 for varicose veins (VVs) or venous malformations, either as a primary procedure (77%) or an adjunct to surgery (18%) or thermal ablation procedures (5%). Outcomes were recorded for

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up to 1 year post procedure. The severity of venous insufficiency was recorded using the CEAP classification. The primary outcome was the obliteration of varicose veins at 1 week post procedure, classified as either complete, partial (greater than 80% sclerosis of the original visualised varicose veins) or minimal (less than 80% sclerosis with persistence of the majority of the varicosities) using duplex ultrasonography. Secondary outcome measures were frequency of improvement in patient reported venous symptoms, ulcer healing, ulcer recurrence, recurrence of VVs and adverse events up to one year. Foam was created with 1 part Sodium Tetradecyl sulphate 3% with room air (three to four parts) using the Tessari technique and received compression post procedure. Prior to intervention patients were classified as CEAP 2-3 (59%), 4-6 (40%) and venous malformations (2%). The majority of varicosities involved the great saphenous vein (GSV) and its tributaries (94%) and 6% involving the small saphenous vein and its tributaries. Median (range)of follow up was 24 (1-156) weeks. Complete obliteration at 1 week was achieved in 65% of legs, partial obliteration was achieved by 34% and 0.9% (n=2) had minimal obliteration. A further 39 legs achieved complete obliteration after further injections of EFS. At 12 weeks 109/164 legs (66%) continued to have complete obliteration, 53/164 (32%) had partial obliteration. At 24 weeks 78/122 (64%) had complete obliteration, 42/122 had partial obliteration. In addition 94% of limbs achieved symptomatic improvement at 1 week. At 24 weeks, 11/122 (91%) of patients reported symptomatic improvement. 17/19 (89%) of ulcers had healed and 10/122 (8%) had developed recurrent varicose veins. There were 5 cases of DVT (2%). Two patients developed neurological side effects including visual disturbances and headache (n=1) and transient confusion and dysarthria (n=1) that completely resolved within hours, both were subsequently found to have a patent foramen ovale. The authors conclude that EFS is a safe and effective treatment for symptomatic and complicated VVs.

This study provides useful data from a moderately sized and consecutive cohort with regard to early technical success rates and symptomatic improvements following EFS for patients classified as CEAP C2C6. Early occlusion rates of complete or greater than 80% occlusion were achieved in 99% of cases at 1 week, with a further 18 % achieving complete occlusion following further injections. These early success rates are similar to those published previously1 although the significant number of patients lost to follow up at 6 months makes it difficult to interpret the technical findings in comparison to other studies of foam sclerotherapy or alternative endovenous therapies. Never the less, the publication of consecutive cohorts of patients provides 1 Darvall KA, Bate GR, Adam DJ, Silverman SH, Bradbury AW. Duplex ultrasound outcomes following ultrasound-guided foam sclerotherapy of symptomatic primary great saphenous varicose veins. Eur J Vasc Endovasc Surg 2010;40(4):534-9.

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valuable information, particularly with regard to complications and serious adverse events, including the incidence of deep venous thrombosis and neurological side effects which are likely to be under reported. The reported incidence of DVT is similar to rates reported in the published literature2, however, at many centres early post operative duplex is not performed and the true incidence of asymptomatic DVT and its consequences are difficult to ascertain. The occurrence of neurological complications following foam sclerotherapy has been a recent cause for concern. This study confirms that transient neurological side effects are uncommon and occur approximately 1% of the time, with the majority rapidly resolving.

The authors of the study acknowledge a number of limitations, in particular the lack of a validated system specific questionnaire or clinical severity score in order to evaluate clinical and functional improvements post intervention. Although symptomatic improvements are recorded, a validated questionnaire would have been valuable in allowing a comparison of outcomes with other similar cohorts and is now recommended as an outcome measure following endovenous ablation proceudres3. The authors also make a comparison with other endovenous techniques including EVLT and RFA although these are not performed in this study. However, the recently published randomised trial conducted by Rasmussen et al4 comparing thermal ablation (EVLT + RFA), foam sclerotherapy and conventional surgery showed no significant difference in early failure rates up to 1 month between the four treatment modalities. However foam sclerotherapy had significantly higher technical failure rates at 1 year, although both foam sclerotherapy and radiofrequency ablation were associated with significantly less post procedural pain and faster recovery times. Interestingly a recent Cochran review5 has highlighted the lack of randomised clinical trials comparing foam sclerotherapy to surgery or other treatment modalities and highlights the need for further research and robust outcome measures. Of great importance are clinical and functional outcomes in addition to occlusion rates. In summary, the study provides further evidence to support foam sclerotherapy as a safe and effective technique. Despite poorer occlusion rates in comparison to thermal ablation techniques, the majority of patients report symptomatic and clinical improvements associated with high levels of patient satisfaction following foam sclerotherapy.

2 Guex JJ. Complications and side-effects of foam sclerotherapy. Phlebology 2009;24(6):270-4. 3 Kundu S, Lurie F, Millward SF, Padberg F, Jr., Vedantham S, Elias S, et al. Recommended reporting standards for endovenous ablation for the treatment of venous insufficiency: joint statement of The American Venous Forum and The Society of Interventional Radiology. J Vasc Surg 2007;46(3):582-9. 4 Rasmussen LH, Lawaetz M, Bjoern L, Vennits B, Blemings A, Eklof B. Randomized clinical trial comparing endovenous laser ablation, radiofrequency ablation, foam sclerotherapy and surgical stripping for great saphenous varicose veins. Br J Surg 2011;98(8):1079-87. 5 Nesbitt C, Eifell RK, Coyne P, Badri H, Bhattacharya V, Stansby G. Endovenous ablation (radiofrequency and laser) and foam sclerotherapy versus conventional surgery for great saphenous vein varices. Cochrane Database Syst Rev 2011(10):CD005624.

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An Economic Evaluation of Venous Thromboembolic Prophylaxis Strategies in Critically Ill Patients at Risk of Bleeding: Review and Commentary

Chaisson TC, Manns BJ, and Stelfox HT. PLoS Med 6(6): e1000098. doi:10.371/journal.pmed.1000098 Reviewer: Timothy K. Liem, MD FACS

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REVIEW: Chaisson et al. performed a decision analysis, to determine the cost effectiveness of three strategies for the prevention of venous thromboembolism (VTE) in trauma patients.1 Pneumatic compression devices (PCD) with expectant management alone, serial duplex ultrasound (SDU) screening for deep vein thrombosis (DVT), and prophylactic vena cava filter (VCF) insertion were compared using Markov modeling. Costs (Canadian $) were estimated at post injury week 12 and over the

When sensitivity analysis was performed, serial duplex ultrasound remained the most costeffective strategy.

lifetime of the patient.

This type of modeling required a base case scenario: a cohort of trauma patients (average age of 40 years) with severe injury in whom there was a contraindication to pharmacologic VTE prophylaxis for 2 weeks. Data regarding the incidence of DVT and pulmonary embolism (PE), the natural history of treated and untreated VTE in trauma patients, and the sensitivity and specificity of venous duplex scanning were obtained from published clinical trials. The cost of care and the clinical outcomes, as measured by quality-adjusted life years (QALY), were obtained from a cohort of â&#x20AC;&#x153;realâ&#x20AC;? trauma patients with similar injury severity scores (>12) who were cared for at a regional trauma center in Alberta, Canada. Once the cost analysis was performed for the base case scenario, the model was tested with a range of hospital costs and probabilities to determine their effect on overall cost effectiveness (sensitivity analysis).

At 12 weeks post injury, the estimated incidence of DVT was higher in patients treated with VCF insertion (25.7%), when compared with patients receiving PCD (14.9%) or SDU (15.0%). Although the estimated incidence of PE was lower with VCF insertion (0.3%), there was no difference in mortality among the three groups. Overall costs at 12 weeks were $55,831 for PCD, $55,334 for SDU, and $57,377 for VCF insertion. Overall costs for the lifetime of the patient were $66,900 for PCD, $65,800 for SDU, and $68,700 for VCF. When sensitivity analysis was performed, SDU remained the most cost-effective strategy.

COMMENTARY: Decision analysis uses mathematical models to represent clinical scenarios for which a statistical analysis may help determine the best course of action. Chaisson et al. performed a well thought out decision analysis comparing three VTE prevention strategies. Their modeling of cost-effectiveness was rigorous enough to include the lifetime costs associated with the risk of mild, moderate, or severe post-thrombotic syndrome. The authors applied Markov analysis, a decision model which takes into account the risk of an event occurring over time, and the possibility

1 Chaisson TC, Manns BJ, and Stelfox HT. An economic evaluation of venous thromboembolism prophylaxis strategies in critically ill trauma patients at risk of bleeding. PLoS Med 6(6): e1000098.doi:10.371/journal.pmed.1000098

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that an event (DVT, PE) may occur once or more than once.2 This is in contrast to other models that analyze an outcome occurring at a defined time point (eg, 5-year survival or 2-year graft patency). However, Markov analysis still requires the application of numerous assumptions, some of which may be valid, and some of which may not. Examples of the latter include the following:

1. The authors assumed that contraindications to pharmacologic VTE prophylaxis resolved after 2 weeks of hospitalization. In reality, the risk of bleeding probably decreases gradually over time, and pharmacologic VTE prophylaxis often may be administered before this 2-week â&#x20AC;&#x153;high-riskâ&#x20AC;? window expires.

2. All patients with a DVT diagnosed within the first 2 weeks were assumed to be treated with an IVC filter. The authors did not clarify if this referred to proximal DVT only or if isolated calf DVTs were included. In patients with contraindications to anticoagulation, serial duplex ultrasound is a reasonable alternative when a DVT is limited to the calf veins.

3. Patients with an IVC filter were assumed to receive therapeutic anticoagulation, only if they were diagnosed with a PE, but not with a DVT. This is in contrast to our practice of frequently reassessing DVT patients who have initial contraindications to anticoagulation. Often times, anticoagulation may be initiated once the contraindication wanes.

4. Patients who needed therapeutic anticoagulation for an established VTE were assumed to receive ongoing anticoagulation for a 1-year period. This is in contrast to the recommendations from The American College of Chest Physicians Evidence-Based Clinical Practice Guidelines, which recommend 3 months of anticoagulation for patients with VTE secondary to a transient risk factor.3

Despite these limitations, our trauma and vascular surgeons would agree with the practice of continued SDU for critically ill trauma patients. In fact, our recent publication identified a similar incidence of lower extremity DVT (15.2%) when using a SDU protocol.4 Although 60% of the DVTs in our trauma patients were isolated to the calf veins, they remain clinically relevant since we favor anticoagulation for isolated calf DVTs.

Several other factors and unknowns limit the wide applicability of this study. The costs of a screening ultrasound in Canada differ from those in other countries, and depend on the frequency with which these tests are performed. Our trauma surgeons usually screen ICU patients twice a week, scanning both upper and lower extremities, but the optimal frequency of screening remains to be determined. However, there is a more significant missing piece to the puzzle: Is the natural history of a DVT found on a duplex screening different from that of a symptomatic DVT?

2 Hunink M, Glasziou P, Siegel J, et al. Decision making in health and medicine: integrating evidence and values. 9th ed. Cambridge, England: Cambridge University Press; 2010: 305-338. 3 Kearon C, Kahn SR, Agnelli G, et al. Antithrombotic therapy for venous thromboembolic disease: American college of chest physicians evidencebased clinical practice guidelines (8th edition). Chest 2008; 133: 454-545. 4 Azarbal A, Rowell S, Lewis J, et al. Duplex ultrasound screening detects high rates of deep vein thrombosis in critically ill trauma patients. J Vasc Surg 2011; 54: 743-748.

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Development and validation of risk prediction algorithm (QThrombosis) to estimate future risk of venous thromboembolism: prospective cohort study Hippisley-Cox, et al: BMJ. 2011 Aug 16;343:d4656. doi: 10.1136/bmj.d4656. Reviewer: Philip Coleridge Smith MD FRCS

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COMMENTARY: This paper addresses the subject of risk factors associated with deep vein thrombosis (DVT) and pulmonary embolism (PE) amongst patients treated in General Practice in the United Kingdom. The authors have taken the data from the QResearch database. These data were culled from the electronic medical records of patients registered with practises using Egton Medical Information Systems software in England and Wales. The dataset recorded for these patients is included as part of their standard registration information. The outcome data was obtained both from the GP databases and from the Office of National Statistics cause of death records. The patient cohort included was 2.3 million patients. Two thirds of the data were used to derive the risk factors and one third which was used as a validation cohort to test the conclusions of the analysis. Cox proportional hazards models were used to calculate the coefficients for various risk factors separately for men and women. The overall incidence of venous thromboembolism (VTE) was 1.5 cases per 1000 patients per year 14,756 cases in all, which is consistent with several other publications. 39% of patients presented with pulmonary embolism and 61% with deep vein thrombosis. 4.9% of patients were identified from death records which gives a rough estimate of the frequency of death in this study which is otherwise not stated.

The risk factors identified by the author as associated with VTE include cancer, chronic renal disease, congestive heart failure, chronic obstructive airways disease, inflammatory bowel disease, hospital admission within 6 months and varicose veins. Drug treatment associated with VTE included antipsychotic drugs, tamoxifen, oral contraceptives and hormone replacement therapy. The author has published a simple calculator based on the parameters developed during this study. This is available on the web at www.QThrombosis.org which allows us all to calculate our risk of venous thrombosis.

The value of this study is that it includes a large population (2.3 million patients) in whom the data is likely to be reasonably reliable and it comes from direct observation. However, the database was general and the collection and identification of cases was not specifically aimed at detecting venous thrombosis. There was no independent confirmation of the diagnoses. There is some scope for the diagnosis being incorrectly allocated.

The QThrombosis calculator was designed by the author to allow calculation of risk of VTE in individual patients. In General Practice this would not have a direct application since thromboprophylaxis would not normally be undertaken in such a setting. Anticoagulation for venous thromboembolism would not normally be commenced except in response to an episode of DVT or PE. The risk calculator does not aim to show the likelihood of DVT in a patient presenting with a suspicion of symptoms of venous thromboembolism so would not be effective in this context either. Perhaps one of the more useful aspects of this calculator would be its assistance for General Practitioners in advising patients on lifestyle modifications. Some of the most frequent factors which may result in ill health are morbid obesity and smoking. Both of these are revealed by the QThrombosis calculator as increasing the risk of venous thrombosis and might assist a GP in advising patients on how to take measures to improve their health.

The calculator is not useful for pre-operative assessment of risk of DVT following surgery or hospital treatment. The data was not collected for this purpose and it does not take into account the type or duration of proposed surgery. Neither does it consider the risk of haemorrhage following anticoagulant prophylaxis. The Department

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of Health in the UK has published a risk calculator for pre-operative use to assist in selecting the correct method of prophylaxis.1 However, the data clearly show which patients may be those at increased risk although much of what has been found here has been established in other studies. The calculator shows that risk increases with age, in patients receiving hormone therapy and in those with cancer and inflammatory bowel disease. However, it was interesting to see that hospital admission within 6 months, smoking, tamoxifen and antipsychotic treatment were also risk factors.

GPs may be consulted by patients concerned about the risk of developing DVT following long haul air travel. The QThrombosis calculator was not intended for use in this context either, although it does show which patients would be at greatest risk. The American College of Chest Physicians has published guidelines which include an analysis of the risk of DVT after long haul travel and suggested methods by which DVT may be prevented.2 These recommend that for long haul travel (flights >8 hours in duration) only general measures (regular leg movements, loose fitting clothing and avoiding dehydration) are required. For those with additional risk factors graduated compression stockings or a single injection of low molecular weight heparin could be used. The information from the QThrombosis paper certainly indicates which patients a GP might consider to be at increased risk although the value of anticoagulant treatment suggested in the ACCP guidelines has not been proven.

In summary the article by Hippisley-Cox et al confirms many of my prejudices as to who is at risk of DVT (increasing age, obesity, cancer, oestrogen treatment, some chronic diseases) and it is very reassuring that the data obtained from epidemiological studies has been confirmed in the real world of general practice. The influence of thrombophilias could not be assessed in this study since few patients had thrombophilia screening undertaken and these data were not readily available to the investigators. The QThrombosis calculator is interesting to use to assess oneâ&#x20AC;&#x2122;s own risk of DVT according to the authorsâ&#x20AC;&#x2122; data but probably has limited clinical applications. However, it is valuable for all of us in medical practice to understand the factors which expose our patients to an increased risk of VTE.

...it is very reassuring that the data obtained from epidemiological studies has been confirmed in the real world of general practice.

1 Department of Health. National Venous Thromboembolism Risk Assessment tool. Department of Health, London UK, 2010. http://www.dh.gov.uk/ en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/DH_088215 (last accessed 14th January 2012). 2 Geerts WH, Bergqvist D, Pineo GF, Heit JA, Samama CM, Lassen MR, Colwell CW. American College of Chest Physicians. Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. 2008; 133( 6 Suppl):381S-453S.

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Incidence of and risk factors for iliocaval venous obstruction

in patients with active or healed venous leg ulcers William Marston, MD, Daniel Fish, BS, Johua Unger, MD, and Blair Keagy, MD Journal of Vascular Surgery 2011;53:1303-1308. Reviewer: Robert L. Kistner, MD This is a well designed diagnostic study of patients with active and healed venous ulcers to identify the frequency and severity of obstructive disease in their iliac veins (iliocaval obstruction = ICVO), and to identify specific risk factors associated with ulcer occurrence in these cases. A secondary goal was to examine the utility of duplex ultrasound scans of the common femoral vein (CFV) in predicting the presence of ICVO as identified by CT or MR venography. This was found to be useful when the CFV waveform was positive as determined by a lack of respiratory variation or response to augmentation maneuvers but the CFV study does not reliably rule out significant iliocaval obstruction when it is negative (normal study).

This was a consecutive series of healed or active venous ulcer cases encountered during an 18 month period excepting patients with morbid obesity (defined as >400 lbs) or individuals who were physically unable to stand for the testing procedure. All patients had a thorough venous ultrasound study of the leg vein from the common femoral through the popliteal vein in addition to either a CT or MR study of the iliocaval veins. There

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were 64 patients and 78 limbs in the study. CT was done in 62 patients and MR in 2 patients. In each limb the pattern of reflux in the extremity and the extent of obstruction in the pelvic iliocaval veins was documented. In this series 37% of iliac imaging studies demonstrated iliocaval obstructions of 50% or greater, and 23% had obstruction of >80%. Important statistical associations included the finding that no limb with superficial venous reflux alone was found to have ICVO of >80%, and independently associated factors of statistical importance were female gender, medical history of DVT, and reflux in the deep system.

Using this information the authors presented an algorithm for practical workup of the CVI patient in which the presence or absence of respiratory variation in the common femoral vein during the ultrasound examination of the extremity is noted as a key finding. In limbs where the CFV shows normal respiratory variation attention is directed at the history of DVT and presence or absence of deep venous reflux as the next key finding. When these are negative no further workup is needed and the patient is considered not to have clinically significant iliac obstructive disease; alternatively, when either is positive a CT venogram of the iliac vein is indicated to determine whether definitive studies and treatment for iliac obstruction is indicated. Conversely, when the initial CFV evaluation is positive by demonstrating a lack of respiratory variation, invasive venography and possible intervention is indicated without further studies being necessary.

The authorsâ&#x20AC;&#x2122; conclusions are that there is a high incidence of ICVO in patients with venous ulceration, and those with a significantly higher risk of iliac obstruction are females, patients with a history of DVT, and patients with deep vein reflux Limbs whose reflux is limited to the superficial veins do not require further study since their incidence of iliac obstruction is extremely low. In this way the initial duplex ultrasound is useful as a screening tool for invasive study of the iliac veins as well as a more definitive study for the extremity reflux patterns. The authors suggest the clinically important degree of iliac obstruction that warrants invasive diagnosis and treatment is 80% since stenoses up to 70% are found in asymptomatic patients.

The principal limitation in this study is the small sample size. The findings are based upon only 18 limbs with ICVO of 80% or greater, and 29 limbs of 50% or greater. The extremity findings included 4 patients with isolated deep axial (CFV, FV, and popliteal) reflux and 1/3 of the series had mixed superficial and deep reflux patterns. An additional 18 limbs had isolated CFV and 11 limbs had isolated popliteal reflux, each associated with superficial reflux; in both of these instances it is known that elimination of the associated superficial reflux is likely to cause the segmental deep reflux to disappear. Another limitation is the lack of identification of primary vs. secondary post-thrombotic disease as an integral part of the CEAP classification.

If future studies with larger numbers of limbs confirm the findings of this study the algorithm described in this article can become an important method to identify which limbs stand to benefit from intervention in the iliac veins. At the moment we have evidence that iliac obstructions are important elements in the venous ulcer problem based upon studies showing important decrease in the recurrence rates of venous ulcers after iliac vein stenting procedures,1 but the practicality and expense of routine definitive study leading to selective treatment of the iliac vein is prohibitive. Associations found in this article can become of real value.

1 Stenting of the venous outflow in chronic venous disease: long-term stent-related outcome, clinical, and hemodynamic result. Neglen P, Hollis J, Olivier J, Raju S. J Vasc Surg 2007;46:979-990

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Advanced Ultrasound Skills Course March 23, 2012 // San Francisco, CA Learn to effectively review patient history and appraise sonographic findings that merit additional scanning or interventional techniques; differentiate between normal, abnormal and physiologic perforating veins; determine the hemodynamic source of reflux location as it relates to the supra or infrainguinal crease; and identify both truncular and extra-truncular venous malformations.

Ultrasound Registry Review Course March 24, 2012 // San Francisco, CA Join the experts in the field to review venous and arterial anatomy and pathophysiology. The course will help you distinguish treatment choices based on patient presentation, maintain and achieve a quality testing facility, leverage non-invasive testing options and prepare you for the CCI Registered Phlebology Sonographer (RPhS) credentialing examination.

Nursing Sclerotherapy Course March 24, 2012 // San Francisco, CA Further your knowledge of sclerotherapy and how it is used to treat venous insufficiency. The course will discuss the need for pre- and post-procedure education to achieve optimal treatment results, helping you to identify possible complications and manage complex clinical issues involving sclerotherapy as the treatment modality.

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Phlebology Forum Jan-Feb 2012 Issue  

Publishing digitally, Phlebology Forum is a peer-reviewed journal dedicated to important topics in phlebology. Each bi-monthly issue will in...

Phlebology Forum Jan-Feb 2012 Issue  

Publishing digitally, Phlebology Forum is a peer-reviewed journal dedicated to important topics in phlebology. Each bi-monthly issue will in...

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