New concepts on recurrence of varicose veins according to the different treatment techniques.

Recurrent varicose veins remain a common problem after varicose vein treatment. Several etiologies have been recognized: tactical and technical failure, neovascularisation, and recanalisation of a previously obliterated trunk and progression of the disease. With the widespread use of duplex ultrasound and increasing experience in the field of ultrasound-guided procedures, the impact of both tactical and technical failure is likely to diminish. However this issue still needs our attention, as it may induce early recurrence after all types of intervention. Another etiologic factor is neovascularisation, occurring in particular after surgery at the level of the saphenofemoral junction (SFJ) or saphenopopliteal junction (SPJ). To explain recurrence after endovenous ablation (EVA) the focus has rather been on recanalisation of a previously obliterated trunk. It is well known that such recanalisation occurs more frequently after chemical ablation with sclerosant foam than after thermal ablation. The incidence of neovascularisation at the SFJ or SPJ is much lower after EVA than after surgical procedures. However this does not mean that the junctions are never involved in recurrence after EVA. It is therefore also important to follow the evolution at the level of the SFJ or SPJ by means of duplex ultrasound, as new (or persistent) reflux may be detected sonographically. Progression of the disease cannot be avoided and is an important contributory factor in the pathophysiology of recurrence at long term. Apart from genetic factors, other patient-related factors (BMI >= 30, pregnancy after the intervention ... ) have been claimed to be responsible for progression of the disease and hence recurrence. Due to disease progression after several years, tortuous neovascular veins or (newly) refluxing veins at the junction may connect with superficial varicose veins of the thigh or leg, acting as a 'joint venture' and in this way lead to the clinical situation of a full-blown recurrence of varicose veins. To increase our understanding of varicose vein recurrence, future studies are needed, including adequate preoperative duplex ultrasound investigation and long-term follow-up with serial duplex scans, after different forms of varicose vein treatment.