Prevention and treatment of venous thromboembolism--International Consensus Statement

The aim of this document is to provide a clear and concise account of the evidence regarding efficacy or harm for various methods available to prevent and manage venous thromboembolism (VTE).

Responsiveness of individual questions from the venous clinical severity score and the Aberdeen varicose vein questionnaire

Objectives

The venous clinical severity score (VCSS) and the Aberdeen varicose vein questionnaire (AVVQ) improve after treating chronic venous insufficiency (CVI). The aim was to examine how and why they improve by evaluating the change in each individual question.

Methods

This was an analysis on prospectively collected data from a clinical study on 100 patients (58% female) with CVI (C2 = 34, C3 = 14, C4a = 29, C4b = 9, C5 = 7, C6 = 7) who were randomized to endovenous laser ablation ( n = 50) or foam sclerotherapy ( n = 50). The change scores (performance) of each question of the VCSS (questions 1–10) and the AVVQ (questions 1–13) were calculated by subtracting the score at three weeks, and three months, from the pre-treatment score.

Results

Both the median, interquartile range (IQR), VCSS and the AVVQ scores improved from 6 (4) and 21.4 (15.1) at baseline to 3 (4) and 18.6 (12.1) at three weeks ( P < 0.0005, P = 0.031) to 2 (3) and 8.8 (13.6) at three months, ( P < 0.0005, P < 0.0005), respectively. The performance of the first three questions of the VCSS (pain, extent of varicosities, oedema) were the most contributory to the overall score. Questions 5, 7, 8, 9 on ulceration improved the most individually but did not contribute significantly to the overall score. Questions 5, 9 of the AVVQ on stocking use and ulceration failed to contribute statistically to the overall improvement at three months.

Conclusion

The majority of the individual questions of the VCSS and AVVQ responded to change. However, the cause of a poor response was multifactorial with statistical dilution playing a significant role. Stratification of patients according to ulceration may allow better comparisons.

Cost and effectiveness of laser with phlebectomies compared with foam sclerotherapy in superficial venous insufficiency. Early results of a randomised controlled trial

OBJECTIVES

Quantify endovenous laser ablation (EVLA) with concurrent phlebectomies and ultrasound-guided foam sclerotherapy (UGFS) in cost and effectiveness at 3 weeks and 3 months.

DESIGN

Single-centre, prospective, randomised controlled trial.

PATIENTS

One hundred patients (100 legs), C(2-6), age 21-78, M:F 42:58, with primary varicose veins received either EVLA under local anaesthetic or UGFS.

METHODS

Assessments included duplex, Aberdeen varicose vein questionnaire (AVVQ), venous clinical severity score (VCSS), venous filling index (VFI), visual analogue 7-day pain score and analgesia requirements. Additional treatments with UGFS were performed, if required. Micro-costing, using individually timed treatments, was based on consumables, staff pay and overheads.

RESULTS

Changes in AVVQ, VCSS and VFI values (3 months) did not demonstrate any significant difference between groups. At 3 months, the above-knee GSV occlusion rate (without co-existing reflux) was not significantly different between the groups (74% vs 69%; EVLA vs UGFS; P = .596). Of the 9 haemodynamic failures in each group, 7 EVLA patients and 4 UGFS patients had co-existing cross-sectional above-knee GSV occlusion at some point. However, UGFS significantly outperformed EVLA in cost, treatment duration, pain, analgesia requirements and recovery.

CONCLUSIONS

UGFS is 3.15 times less expensive than EVLA (£230.24 vs £724.72) with comparable effectiveness but 56% (versus 6%) required additional foam (ISRCTN:03080206).

Magnetic resonance venous velocity mapping during intermittent pneumatic compression of the calf and foot

Objective

Assessment and optimization of intermittent pneumatic compression (IPC) devices for prophylaxis of deep vein thrombosis has previously used duplex ultrasound. The aim was to investigate novel magnetic resonance (MR) venous velocity mapping (VM) for IPC research and development.

Methods

Twelve normal subjects were scanned in the supine position using realtime MR VM with sequential foot and calf IPC (120 mmHg) at 1.5 T. Measurements were taken in the popliteal vein at baseline using both cuffs and each cuff individually recording 60 seconds continuously. Temporal resolution was 310 ms per independent image, at 1 ×1 mm spatial resolution.

Results

Peak velocity ( Vp) measurements: baseline, Vp = 2.1 cm/second (range = 1.1–3.5); using both compression cuffs, Vp = 41.5 cm/second (18.0–58.1); calf cuff alone, Vp = 40.6 cm/second (18.1–62.2); foot cuff alone, Vp = 7.9 cm/second (4.2–15.3). Flow volume measurements per compression cycle ( F): baseline, F = 2.3 cm3 (0.5–11.4); both compression cuffs, F = 7.1 cm3 (2.5–24.6); calf cuff only, F = 7.1 cm3 (2.4–24.5); foot cuff only, F = 2.6 cm3 (0.9–10.7). The foot cuff contribution was insignificant when combined with the calf cuff ( P < 0.01). The MR venous VM results were similar to those reported elsewhere using ultrasound.

Conclusion

This novel technique for MR venous VM can measure the realtime variations in venous blood flow during IPC.

The efficacy of a new stimulation technology to increase venous flow and prevent venous stasis

OBJECTIVES

Electrical stimulation of calf muscles has been shown to be effective in prevention of DVT. The aim was to determine: (a) dependence of venous blood velocity and ejected volume on the rates of stimulated calf contractions: (b) clinical factors affecting efficacy in healthy individuals.

METHODS

The maximum intensity stimulus tolerated was applied to calves of 24 volunteers. In popliteal veins, peak systolic velocities (PSV), ejected volume per individual stimulus (stroke volume SV) and ejected total volume flow per minute (TVF) of expelled blood were determined using ultrasound. Stimulation rates from 2 to 120 beats per minute (bpm) were applied.

RESULTS

Mean baseline popliteal PSV was 10 cm/s. For stimulation rates between 2 and 8 bpm, the PSV was 10 times higher and reached 96-105 cm/s. Stroke volume (SV) per individual stimulus decreased in a similar fashion. With increasing rates of stimulation the TVF increased by a factor of 12 times (from 20 ml/min to 240 ml/min).

CONCLUSION

Electrical stimulation is an effective method of activating the calf muscle pump. Enhancements of popliteal blood velocity and volume flow are key factors in the prevention of venous stasis and DVT. Further studies are justified to determine the stimulation rates in those with a compromised venous system.

Immediate Hemodynamic Effect of the Additional Use of the SCD EXPRESS™ Compression System in Patients with Venous Ulcers Treated with the Four-layer Compression Bandaging System

OBJECTIVES

To test the hypothesis that the SCD EXPRESS intermittent pneumatic compression applied in combination with a four-layer bandage in patients with venous ulcers increases popliteal vein volume flow and velocity.

DESIGN

Twenty limbs of 18 patients with venous leg ulcers were studied, median age 76 years. The Total Volume Flow (TVF) and the Peak Systolic Velocity (PSV) were recorded in the popliteal vein using duplex ultrasonography. Measurements were made (i) without bandage, (ii) with four layer bandage and (iii) following the application of the SCD Compression System on top of a four-layer bandage for at least 15 minutes.

RESULTS

The median VCSS was 17 (range, 12-22) while the median VSDS for reflux was 4.5 (range, 1-7.5). The median TVF was 71 mL/min (inter-quartile range 57-101) without bandage, 112 (IQR 89-148) with four-layer bandage and 291 (IQR 241-392) with the addition of the SCD System (P<.001, Wilcoxon signed ranks test). The median PSV was 8.4 cm/sec (IQR 6.8-14) without bandage, 13 (9.0-19) with four-layer bandage and 27 (21-31) with the addition of the SCD System (P<.001, Wilcoxon signed ranks test). Both TVF and PSV increased slightly with the addition of the four-layer bandage. However, with the addition of the SCD System these parameters increased three fold.

CONCLUSIONS

The SCD EXPRESS Compression System accelerates venous flow in the legs of patients with venous ulcers already treated with a four-layer bandage. The combination of four-layer compression with the SCD System on healing venous ulcers needs to be tested by a clinical effectiveness study.