It is estimated that between 100,000 to 150,000 people currently inject drugs in England [1, 2]. Investigations of samples from this population suggest that between a third and one half use the femoral vein (FV) in the groin as their main injecting site [3–5]. Groin injecting (GI) is associated with significant risks of injury to the FV and femoral artery (FA) and bacterial and blood borne viral infections . More serious medical complications such as deep vein thrombosis (DVT), pulmonary embolism, chronic venous disease (CVD) and compromise to the adjacent FA with consequent risk of gangrene have also been reported [7–10]. Groin injectors (GIs) are often unaware of these risks and consequently, tend to present late for treatment of injecting complications . Hospitalisation of drug users for infections and vascular damage caused by injecting drug use (IDU) has recently increased in England . Cessation of GI is related to greater treatment retention, but is also a function of more severe venous disease . This suggests that innovative approaches are needed, which can better engage people who inject in the FV, so that problems can be recognised and responded to more quickly and earlier cessation of GI can be promoted.
Ultrasonography is a non-invasive procedure for investigating venous and arterial diseases . Ultrasound scanners use high frequency sound waves to produce two-dimensional anatomical images and spectral tracings that can demonstrate vein damage (scarring, narrowing or blockage by blood clot), arterial damage (e.g. aneurysm) as well as changes in venous and arterial blood flow. Ultrasonography is safe and the latest scanners are low cost, portable and capable of producing clear images [14, 15]. Ultrasound scanners are increasingly being used by non-radiologists to enhance the speed and accuracy of clinical examinations  but the benefits of the technology are yet to be evaluated in drug treatment settings.
Some drug treatment services offer harm reduction advice and information including leaflets to GIs [17, 18], but little is known about their effectiveness [19, 20]. In isolation, simple advice and information that cautions against GI may have limited efficacy. We hypothesized that ultrasound scanning might better engage injecting drug users in discussion about GI risks and help to improve our understanding of the patho-physiology of FV damage and CVD among GIs.
The new point-of-care ultrasound service was established to provide current and former GIs with easy access to ultrasound assessment of anatomical and functional status of FV segment at their groin injecting site(s). Referral pathways to relevant medical and surgical interventions were identified for patients experiencing complications of GI. This paper describes:
1. How the service was established, the operation of the service, the scanning procedure and the characteristics of clinic attendees.
2. The clinical presentation, ultrasound findings and a grading system for the types of FV damage identified among GIs.