Clots in surface veins referred to as superficial thrombophlebitis (STP) is a common clinical presentation. The great saphenous vein (GSV) is involved in about two-thirds and the small saphenous vein (SSV) in about 10-20%, while STP is bilateral in 5-10% of patients. It is up to six times more common in patients with varicose veins, particularly if they are older or obese. Other risk factors are the same as those for deep vein thrombosis (DVT) including previous thromboembolic events, long-haul flights, pregnancy, oral contraceptives, hormone replacement therapy, immobilization or recent surgery.
Up to 20% of patients with STP will extend the clot to become a DVT. Clots passing to the lungs may occur in up to 20% of patients with STP in the above knee GSV.
STP presents with local pain and inflammation and the affected vein becomes solid. Evaluation is best made by ultrasound to confirm the diagnosis, estimate its extent, determine if there is DVT and for follow-up. Initially, both legs should be examined.
Current international recommendations for treatment are as follows.
- In general, surgical ligation of the proximal saphenous vein has no advantage over anticoagulation alone.
- Low molecular weight heparin (LMWH) in intermediate doses is the most effective anticoagulant and ideally should be continued for one month.
- However, conventional anticoagulation with initial LMWH and warfarin which is continued for six weeks is almost as effective and more simple to manage.
- For isolated STP at the below knee segment confined to varicosities, anti-inflammatory drugs and local application of hirudoid cream is an acceptable treatment option.
- Compression bandages or stockings are worn until pain has gone.
- Antibiotics have no role in the management of STP.
