David T. Loveday, Nicholas J.O. Hutt, Veronica Roberts, Rajesh Kakwani.
Response/Recommendation: In the absence of concrete evidence, we recommend that venous thromboembolism (VTE) prophylaxis (mechanical and/or chemical) be administered to patients at high risk of VTE (as determined by the risk stratification scores) unless contraindicated. Routine administration of chemoprophylaxis for patients undergoing achilles repair is not supported by the current literature.
Strength of Recommendation: Weak.
Rationale: A systematic review was conducted to answer this clinical question. The search revealed five randomized control trials and a few retrospective studies including one on a very large cohort in a national registry. Overall, there was considerable heterogeneity between the studies. There was variability in the type of VTE prophylaxis, duration of prophylaxis, and the mode of diagnosis of VTE. The postoperative protocols also varied in immobilization type, duration, and weight-bearing status. Results from the studies could therefore not be pooled together. A previous meta-analysis on foot and ankle surgery including achilles tendon ruptures reported a symptomatic VTE incidence of 7% (95% confidence interval [CI] 5.5-8.5%) and radiologically diagnosed VTE incidence of 35.5% (95% CI 26.4-44.3%)1. The meta-analysis recommended that VTE chemoprophylaxis should be administered to patients undergoing achilles tendon surgery.
The RCT that we evaluated included a small cohort size ranging from 26 to 150. Three clinical trials were conducted by the same investigators on the role of mechanical prophylaxis. These studies included ultrasound screening of patients at 2 and 6 weeks after achilles tendon repair. They compared early functional mobilisation2, calf intermittent pneumatic compression (IPC)3 or foot IPC4 to not having these in the rehabilitation after an achilles tendon repair. The calf IPC reduced the incidence of ultrasound screened VTE at two weeks (odds ratio [OR] = 2.60; 95% CI 1.15 – 5.91; p =0.022) but not at six weeks (OR 0.94, 95% CI 0.49 – 1.83). There was no difference between the early functional mobilization or foot IPC.
The other RTC with moderate study quality compared chemical VTE prophylaxis using low-molecular-weight heparin (LMWH) to placebo. One study with 88 patients reported a reduction in VTE with LMWH compared to placebo for patients undergoing achilles tendon rupture who were immobilized in a plaster cast (OR, 0.24; 95% CI, 0.06 – 0.98)5. The study was on a larger cohort of 440 patients who were immobilized in a cast because of lower leg injuries. The achilles tendon injury patients were a sub-cohort. The study did not provide details of how the achilles tendon injuries were treated. Another RCT study included a cohort of 105 patients undergoing surgical repair of achilles tendon and immobilized in a plaster cast. There was no difference in the incidence of VTE among patients receiving LMWH (34%) vs. placebo (36%)6.
A retrospective study reviewed the incidence of VTE among 28,546 patients with achilles tendon rupture who were treated surgically or non-operatively7. None of these patients, because of national guidelines, received VTE prophylaxis. The incidence of VTE within 180 days, that required hospitalization, in this large cohort was 1.36%.
One study on 341 patients with achilles tendon rupture, undergoing surgical repair and cast immobilization, had a deep venous thrombosis (DVT) incidence of 46% detected by ultrasound screening8. None of the patients in the latter study received VTE prophylaxis. Variation in the incidence of symptomatic VTE has also been observed. One study including a cohort of 1,172 patients who received surgical treatment of achilles tendon rupture and were not given VTE prophylaxis had a symptomatic VTE incidence of 0.76%8. Another study reported symptomatic VTE in 23.5% of 115 patients who received non-operative treatment of achilles tendon rupture9. Yet the incidence of symptomatic VTE was 4.5% in a cohort of 288 patients with achilles tendon rupture who were treated non-operatively in a weight-bearing boot and who did not receive any VTE prophylaxis10. The role of aspirin (ASA) as a VTE prophylaxis remains unclear. One retrospective audit study did not detect any reduction in the rate of VTE in patients with achilles tendon rupture who received ASA11.
We also reviewed a few other studies that were either low-quality and/or included a very small cohort size. Based on our understanding of the current literature, the incidence of symptomatic VTE in patients with achilles tendon rupture who are treated surgically or non-operatively continues to be relatively low. The available literature does not provide justification for routine administration of VTE prophylaxis for patients with achilles tendon rupture. In the absence of such evidence, we recommend that VTE prophylaxis should be reserved for patients at high-risk of VTE, as determined by risk stratification scores.
References:
1. Calder JDF, Freeman R, Domeij-Arverud E, van Dijk CN, Ackermann PW. Meta-analysis and suggested guidelines for prevention of venous thromboembolism (VTE) in foot and ankle surgery. Knee Surg Sports Traumatol Arthrosc. 2016;24(4):1409-1420. doi:10.1007/s00167-015-3976-y
2. Aufwerber S, Heijne A, Edman G, Grävare Silbernagel K, Ackermann PW. Early mobilization does not reduce the risk of deep venous thrombosis after Achilles tendon rupture: a randomized controlled trial. Knee Surg Sports Traumatol Arthrosc. 2020;28(1):312-319. doi:10.1007/s00167-019-05767-x
3. Domeij-Arverud E, Labruto F, Latifi A, Nilsson G, Edman G, Ackermann PW. Intermittent pneumatic compression reduces the risk of deep vein thrombosis during post-operative lower limb immobilisation: a prospective randomised trial of acute ruptures of the Achilles tendon. Bone Joint J. 2015;97-B(5):675-680. doi:10.1302/0301-620X.97B5.34581
4. Domeij-Arverud E, Latifi A, Labruto F, Nilsson G, Ackermann PW. Can foot compression under a plaster cast prevent deep-vein thrombosis during lower limb immobilisation? Bone Joint J. 2013;95-B(9):1227-1231. doi:10.1302/0301-620X.95B9.31162
5. Lassen MR, Borris LC, Nakov RL. Use of the low-molecular-weight heparin reviparin to prevent deep-vein thrombosis after leg injury requiring immobilization. N Engl J Med. 2002;347(10):726-730. doi:10.1056/NEJMoa011327
6. Lapidus LJ, Rosfors S, Ponzer S, et al. Prolonged thromboprophylaxis with dalteparin after surgical treatment of achilles tendon rupture: a randomized, placebo-controlled study. J Orthop Trauma. 2007;21(1):52-57. doi:10.1097/01.bot.0000250741.65003.14
7. Pedersen MH, Wahlsten LR, Grønborg H, Gislason GH, Petersen MM, Bonde AN. Symptomatic Venous Thromboembolism After Achilles Tendon Rupture: A Nationwide Danish Cohort Study of 28,546 Patients With Achilles Tendon Rupture. Am J Sports Med. 2019;47(13):3229-3237. doi:10.1177/0363546519876054
8. Saarensilta IA, Edman G, Ackermann PW. Achilles tendon ruptures during summer show the lowest incidence, but exhibit an increased risk of re-rupture. Knee Surg Sports Traumatol Arthrosc. 2020;28(12):3978-3986. doi:10.1007/s00167-020-05982-x
9. Robinson R, Wirt TC, Barbosa C, et al. Routine Use of Low-Molecular-Weight Heparin For Deep Venous Thrombosis Prophylaxis After Foot and Ankle Surgery: A Cost-Effectiveness Analysis. J Foot Ankle Surg. 2018;57(3):543-551. doi:10.1053/j.jfas.2017.12.001
10. Blanco JA, Slater G, Mangwani J. A Prospective Cohort Study of Symptomatic Venous Thromboembolic Events in Foot and Ankle Trauma: The Need for Stratification in Thromboprophylaxis? J Foot Ankle Surg. 2018;57(3):484-488. doi:10.1053/j.jfas.2017.10.036
11. Healy B, Beasley R, Weatherall M. Venous thromboembolism following prolonged cast immobilisation for injury to the tendo Achillis. J Bone Joint Surg Br. 2010;92(5):646-650. doi:10.1302/0301-620X.92B5.23241