Noam Shohat, Gregg Klein, William J. Hozack.
Response/Recommendation: Based on current literature and recommendations from official bodies, patients with an isolated distal deep venous thrombosis (DVT) (in whom a proximal component was not detected at the initial scan) can be managed without anticoagulation but need to have a follow-up ultrasound (US) of the proximal veins after 1 week to rule out DVT extension. It is reasonable to treat the patient empirically with anticoagulation, especially in situations where a follow-up ultrasound may not be possible.
Strength of Recommendation: Consensus.
Rationale: Isolated distal DVT encompasses thromboses of the calf veins below the knee, with the popliteal vein not being involved. Most calf vein DVT are located in the posterior tibial and peroneal veins1–5. The rate of extension to the proximal veins and the rate of pulmonary embolism (PE) is highly variable. Studies have shown that 9%–21.4% of isolated distal DVT may propagate proximally2,4,6.
Venous compression ultrasound (US) is the standard imaging test for patients with suspected lower extremity DVT. Protocols recommended by the American College of Chest Physicians (ACCP)7, American Institute of Ultrasound in Medicine/American College of Radiology/Society of Radiologists in Ultrasound8(p30), and Intersocietal Accreditation Commission Vascular Technology9 have been inconsistent with regards to the necessary components of the US. While scanning the proximal veins is agreed by all societies, the necessity of routine scanning of the distal calf veins remains debatable2,10,11.
If the distal veins are imaged and isolated distal DVT is diagnosed, the two treatment strategies involve either treating the patient with anticoagulation or holding anticoagulation and following up with repeated US examination. Surveillance studies from non-orthopedic literature suggest that proximal DVT is diagnosed at the second US in 1.9%–12.8% of patients4,12,13.
The majority of orthopedic literature that examined the rate of propagation of distal DVT was conducted in the context of total joint arthroplasty, and mainly total knee arthroplasty (TKA). Barrellier et al., conducted a randomized prospective study14 comparing short versus extended venous thromboembolism (VTE) prophylaxis. While not the main outcomes, the authors found that distal DVT progressed to the proximal veins in 27 of 141 patients (19.1%) who received short-term prophylaxis. In those who received extended VTE prophylaxis, the rate was significantly lower but still affected 9 of 144 patients (6.3%), suggesting the need for routine surveillance of the proximal veins regardless of prophylaxis modality. Several retrospective studies support these findings, although lower rates of propagation were reported; Oishi et al.,15 examined the clinical course of isolated DVT diagnosed with routine US at day 4 postoperatively. Out of 41 asymptomatic patients that were diagnosed with an isolated DVT and had serial US surveillance, seven (17%) developed a proximal DVT in the ipsilateral limb by the fourteenth postoperative day. Tateiwa et al.,16 retrospectively followed up 42 patients with an isolated DVT using consecutive US and reported a DVT exacerbation in five patients (11.9%), three of whom showed additional thrombus formation. The remaining two patients had thrombus elongation or propagation from the distal to proximal veins. More recently Omari et al.,17 retrospectively reviewed 445 patients who were diagnosed with isolated DVT following TKA. The authors reported propagation to the popliteal vein in 10 of 459 patients (2.2%). In contrast with these studies, Yun et al.,18 found no propagation in a 6-month CT follow-up of 39 TKA patients with an isolated DVT. Notably, the methodology of that study had major flaws as half of the cohort (37 of 78 patients) that were diagnosed with isolated DVT on day 7 were not further evaluated and outcomes were not available.
While not intended specifically for orthopedic use, several official bodies have designed protocols for the follow-up of distal DVT, all of which support the continued surveillance of these patients through a serial US of the proximal veins in cases of distal DVT that are managed expectantly5,6,19. Current recommendations entail repeating the US at 1 week and then at 2 weeks if the distal DVT persists but does not extend2. No further imaging is required if the distal DVT resolves at 1 week or does not extend significantly at 2 weeks. Serial US is not indicated if the patient receives anticoagulation unless there is a change in the clinical condition of the patient that warrants a change in treatment20.
Acknowledging the limited data available on the subject, especially in the field of orthopaedics, our literature review suggests that up to 19% of distal DVT may subsequently extend into the proximal veins. It is therefore recommended that anticoagulation be administered immediately, or serial US be performed as surveillance to detect thrombus extension21–24. The abovementioned protocols for surveillance of patients with an isolated DVT should be followed. It should be noted, however, that compliance with repeat US imaging is inconsistent25, so, if a repeat US cannot be done, it may be best to treat that patient with anticoagulation.
1. Kabashneh S, Singh V, Alkassis S. A Comprehensive Literature Review on the Management of Distal Deep Vein Thrombosis. Cureus. 2020;12(5):e8048. doi:10.7759/cureus.8048
2. Bates SM, Jaeschke R, Stevens SM, et al. Diagnosis of DVT: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e351S-e418S. doi:10.1378/chest.11-2299
3. Schellong SM. Distal DVT: worth diagnosing? Yes. J Thromb Haemost. 2007;5 Suppl 1:51-54. doi:10.1111/j.1538-7836.2007.02490.x
4. Kirkilesis G, Kakkos SK, Bicknell C, Salim S, Kakavia K. Treatment of distal deep vein thrombosis. Cochrane Database Syst Rev. 2020;4:CD013422. doi:10.1002/14651858.CD013422.pub2
5. Palareti G, Agnelli G, Imberti D, et al. A commentary: to screen for calf DVT or not to screen? The highly variable practice among Italian centers highlights this important and still unresolved clinical option. Results from the Italian MASTER registry. Thromb Haemost. 2008;99(1):241-244. doi:10.1160/TH07-06-0393
6. Garry J, Duke A, Labropoulos N. Systematic review of the complications following isolated calf deep vein thrombosis. Br J Surg. 2016;103(7):789-796. doi:10.1002/bjs.10152
7. Kearon C, Akl EA, Ornelas J, et al. Antithrombotic Therapy for VTE Disease: CHEST Guideline and Expert Panel Report. Chest. 2016;149(2):315-352. doi:10.1016/j.chest.2015.11.026
8. The American College of Radiology, with more than 30,000 members, is the principal organization of radiologists, radiation onc. :15.
9. Vascular Testing | Download the 2020 IAC Standards. Accessed August 17, 2021. https://www.intersocietal.org/vascular/seeking/vascular_standards.htm
10. Antithrombotic Therapy for VTE Disease – CHEST. Accessed August 17, 2021. https://journal.chestnet.org/article/S0012-3692(12)60129-9/fulltext
11. Righini M, Bounameaux H. Clinical relevance of distal deep vein thrombosis. Curr Opin Pulm Med. 2008;14(5):408-413. doi:10.1097/MCP.0b013e32830460ea
12. Bernardi E, Camporese G, Büller HR, et al. Serial 2-point ultrasonography plus D-dimer vs whole-leg color-coded Doppler ultrasonography for diagnosing suspected symptomatic deep vein thrombosis: a randomized controlled trial. JAMA. 2008;300(14):1653-1659. doi:10.1001/jama.300.14.1653
13. Righini M. Is it worth diagnosing and treating distal deep vein thrombosis? No. J Thromb Haemost. 2007;5 Suppl 1:55-59. doi:10.1111/j.1538-7836.2007.02468.x
14. Barrellier M-T, Lebel B, Parienti J-J, et al. Short versus extended thromboprophylaxis after total knee arthroplasty: a randomized comparison. Thromb Res. 2010;126(4):e298-304. doi:10.1016/j.thromres.2010.07.018
15. Oishi CS, Grady-Benson JC, Otis SM, Colwell CW, Walker RH. The clinical course of distal deep venous thrombosis after total hip and total knee arthroplasty, as determined with duplex ultrasonography. J Bone Joint Surg Am. 1994;76(11):1658-1663. doi:10.2106/00004623-199411000-00009
16. Tateiwa T, Ishida T, Masaoka T, et al. Clinical course of asymptomatic deep vein thrombosis after total knee arthroplasty in Japanese patients. J Orthop Surg (Hong Kong). 2019;27(2):2309499019848095. doi:10.1177/2309499019848095
17. Omari AM, Parcells BW, Levine HB, Seidenstein A, Parvizi J, Klein GR. 2021 John N. Insall Award: Aspirin is effective in preventing propagation of infrapopliteal deep venous thrombosis following total knee arthroplasty. Bone Joint J. 2021;103-B(6 Supple A):18-22. doi:10.1302/0301-620X.103B6.BJJ-2020-2436.R1
18. Yun W-S, Lee KK, Cho J, Kim H-K, Kyung H-S, Huh S. Early treatment outcome of isolated calf vein thrombosis after total knee arthroplasty. J Korean Surg Soc. 2012;82(6):374-379. doi:10.4174/jkss.2012.82.6.374
19. Needleman L, Cronan JJ, Lilly MP, et al. Ultrasound for Lower Extremity Deep Venous Thrombosis. Circulation. 2018;137(14):1505-1515. doi:10.1161/CIRCULATIONAHA.117.030687
20. Society for Vascular Medicine | Choosing Wisely. Published February 24, 2015. Accessed August 17, 2021. https://www.choosingwisely.org/societies/society-for-vascular-medicine/
21. Masuda EM, Kistner RL, Musikasinthorn C, Liquido F, Geling O, He Q. The controversy of managing calf vein thrombosis. J Vasc Surg. 2012;55(2):550-561. doi:10.1016/j.jvs.2011.05.092
22. Hughes MJ, Stein PD, Matta F. Silent pulmonary embolism in patients with distal deep venous thrombosis: systematic review. Thromb Res. 2014;134(6):1182-1185. doi:10.1016/j.thromres.2014.09.036
23. Spencer FA, Kroll A, Lessard D, et al. Isolated calf deep vein thrombosis in the community setting: the Worcester Venous Thromboembolism study. J Thromb Thrombolysis. 2012;33(3):211-217. doi:10.1007/s11239-011-0670-x
24. De Martino RR, Wallaert JB, Rossi AP, Zbehlik AJ, Suckow B, Walsh DB. A meta-analysis of anticoagulation for calf deep venous thrombosis. J Vasc Surg. 2012;56(1):228-237.e1; discussion 236-237. doi:10.1016/j.jvs.2011.09.087
25. McIlrath ST, Blaivas M, Lyon M. Patient follow-up after negative lower extremity bedside ultrasound for deep venous thrombosis in the ED. Am J Emerg Med. 2006;24(3):325-328. doi:10.1016/j.ajem.2005.11.020