In contrast to proximal lower extremity deep venous thrombosis for which anticoagulation (AC) is standard therapy, whether below-knee deep venous thrombosis (BKDVT) (eg, involving peroneal, soleus, tibial, or gastrocnemius veins) should routinely receive AC is a matter of debate because of lack of solid supportive evidence. 1-3
The American College of Chest Physicians (ACCP) recommends AC for patients with BKDVT who are severely symptomatic or have risk factors for extension of the thrombus but this recommendation is based on low-quality scientific evidence (grade 2C or “weak”).3 For other patients, surveillance ultrasound is recommended in 2 weeks to exclude clot propagation more proximally, and therefore the need for AC. Of course, decision regarding AC should be made in the context of the patient’s risk of serious bleeding.
The following facts about BKDVT may help in therapeutic decision making:1
- Most cases resolve spontaneously without AC
- The incidence of propagation varies from 3%-32%
- Embolization is unlikely in the absence of extension into proximal veins
Also remember that clot propagation usually occurs within 2 weeks of initial diagnosis. That’s why surveillance ultrasound is recommended during this period when watchful waiting is preferred.
- Fleck D, Albadawi H, Wallace A, etal. Below-knee deep vein thrombosis (DVT): diagnostic and treatment patterns. Cariovasc Diagn Ther 2017;7(Suppl3):S134-39. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5778527/
- Olson EJ, Zander AL, Van Gent J-M, et al. Below-knee deep vein thrombosis: An opportunity to prevent pulmonary embolism? J Trauma Acute Care Surg 2014;77:459-63. https://www.ncbi.nlm.nih.gov/pubmed/25159251
- Kearon C, Akl EA, Comerota AJ, et al. Antithrombotic therapy for VTE disease. Antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines. CHEST 2012;141 (Suppl):e419S-e494S. https://www.ncbi.nlm.nih.gov/pubmed/22315268