Phlebology: The Journal of Venous Disease

Diagnosis of deep vein thrombosis remains a challenging problem. Various clinical prediction rules have been developed in order to improve diagnosis and decision making in relation to deep vein thrombosis. The purpose of this review is to summarise the available clinical scores and describe their applicability and limitations.

A systematic search of PubMed, MEDLINE and EMBASE databases was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance using the keywords: clinical score, clinical prediction rule, risk assessment, clinical probability, pretest probability, diagnostic score and medical Subject Heading terms: ‘Venous Thromboembolism/diagnosis’ OR ‘Venous Thrombosis/diagnosis’. Both development and validation studies were eligible for inclusion.

The search strategy returned a total of 2036 articles, of which 102 articles met a priori criteria for inclusion. Eight different diagnostic scores were identified. The development of these scores differs in respect of the population included (hospital inpatients, hospital outpatients or primary care patients), the exclusion criteria, the inclusion of distal deep vein thrombosis and the use of D-dimer. The reliability and applicability of the scores in the context of specific subgroups (inpatients, cancer patients, elderly patients and those with recurrent deep vein thrombosis) remains controversial.

Detailed knowledge of the development of the various clinical prediction scores for deep vein thrombosis is essential in understanding the power, generalisability and limitations of these clinical tools.

The aim of this study was to investigate the predictive value of haemodynamic parameters on success of stenting or bypass surgery in patients with non-thrombotic or post-thrombotic deep venous obstruction.

EMBASE, MEDLINE and trial registries were searched up to 5 February 2016. Studies needed to investigate stenting or bypass surgery in patients with post-thrombotic obstruction or stenting for non-thrombotic iliac vein compression. Haemodynamic data needed to be available with prognostic analysis for success of treatment. Two authors, independently, selected studies and extracted data with risk bias assessment using the Quality in Prognosis Studies tool.

Two studies using stenting and two using bypass surgery were included. Three investigated plethysmography, though results varied and confounding was not properly taken into account. Dorsal foot vein pressure and venous refill times appeared to be of influence in one study, though confounding by deep vein incompetence was likely. Another investigated femoral-central pressure gradients without finding statistical significance, though sample size was small without details on statistical methodology. Reduced femoral inflow was found to be a predictor for stent stenosis or occlusion in one study, though patients also received additional surgery to improve stent inflow. Data on prediction of haemodynamic parameters for stenting of non-thrombotic iliac vein compression were not available.

Data on the predictive value of haemodynamic parameters for success of treatment in deep venous obstructive disease are scant and of poor quality. Plethysmography does not seem to be of value in predicting outcome of stenting or bypass surgery in post-thrombotic disease. The relevance of pressure-related parameters is unclear. Reduced flow into the common femoral vein seems to be predictive for in-stent stenosis or occlusion. Further research into the predictive effect of haemodynamic parameters is warranted and the possibility of developing new techniques that evaluate various haemodynamic aspects should be explored.

No work has been reported on the use of video websites to learn about deep vein thrombosis and the value of education using them. We examined the characteristics and scientific accuracy of videos related to deep vein thrombosis on YouTube.

YouTube was surveyed using no filter and the key words ‘deep vein thrombosis’ and ‘leg vein clot’ in June 2016. The videos evaluated were divided into three groups in terms of their scientific content, accuracy, and currency: useful, partly useful, and useless.

Of the 1200 videos watched, 715 (59.58%) were excluded with the exclusion criteria. Although most of the videos uploaded (22.9%, n = 111) were created by physicians, the number of views for website-based videos was significantly higher (p = 0.002). When the uploaded videos were assessed in terms of their usefulness, videos from physicians and hospitals were statistically more useful than other videos (p < 0.001).

For videos created by medical professionals to be of higher quality, we believe they should be more up-to-date and comprehensive, and contain animations about treatment modalities and early diagnosis in particular.

UK National Institute for Health and Care Excellence (NICE) clinical guidelines (CG) 168, published in July 2013, aimed to improve the management of lower limb venous disease by newly recommending interventional treatment for all people affected by symptomatic varicose veins (VV) and specialist vascular referral for all people suffering from a leg ulcer (LU) that had been present for ≥2 weeks. This study aims to determine if CG168 has increased access to vascular services, particularly for the socially deprived, who might be expected to have greater need for such services.

The study was performed in a highly multi-cultural, socio-economically diverse, mixed urban/suburban population of approximately 1.2 million people living in and around East Birmingham, UK. Index of multiple deprivation quintile (IMD-Q) was used as a measure of social deprivation to compare levels of social deprivation of people undergoing interventions for symptomatic VV or referred with an LU during 18-month periods before and after the publication of CG168. The referring general practitioner practices (GPPs) were also recorded.

There was no change in overall IMD-Q distribution before and after CG168 in terms of VV interventions. However, there was a non-significant increase in proportions of people classified as IMD-Q5 (the most deprived quintile). After CG168, fewer IMD-Q5 people with LU were referred, with a shift in referrals towards those from less socially deprived areas. More GPP referred people with both VV and LU after CG168, and those that referred patients before and after CG168 tended to refer more after CG168.

CG168 has increased VV interventions as well as the number referred with LU. However, this improvement in access to treatment and referral may have disproportionately favoured the more socio-economic privileged. Professional and public education is required to ensure that the beneficial impact of the CG168 recommendations are maximised and that those with the greatest health needs have equal access to evidence-based management of their venous disease.