Blood Flow Restriction Resistance Exercise as a Rehabilitation Modality Following Orthopaedic Surgery: A Review of Venous Thromboembolism Risk

Abstract

Synopsis Restoration of skeletal muscle mass and strength are critical to successful outcomes following orthopedic surgery. Blood flow restricted resistance exercise (BFR) has emerged as an attractive candidate to augment traditional low intensity physical rehabilitation exercise, and has yielded successful outcomes over a wide variety of applications. BFR is well tolerated and safe for the majority of individuals, though the post-surgical orthopedic patient has additional considerations due to their heightened risk for venous thromboembolism (VTE). While the pathogenesis of VTE is multifactorial and individual specific, it is commonly described as a combination of blood stasis, endothelial injury, and alterations in the constituents of the blood leading to hypercoagulability. The collective literature suggests that, given the pathogenic mechanisms of VTE, the finite use of a wide, partially occluding cuff during resistance exercise should be low risk and that the likelihood of BFR directly causing a VTE event is remote. Alternatively, it is plausible that BFR may enhance blood flow and promote fibrinolysis. Of greater concern would be the individual with preexisting asymptomatic VTE, which could be dislodged during BFR. Though, it is unknown if the direct risk associated with BFR is greater than the risk associated with traditional exercise alone. Presently, there are no universally agreed upon standards indicating which post-surgical orthopedic patients may perform BFR safely. While excluding all post-surgical orthopedic patients from performing BFR may be overly precautious, clinicians need to thoroughly screen for VTE signs and symptoms, be cognizant of each patient's risk factors, and use proper equipment and prescriptions methods prior to initiating BFR. J Orthop Sports Phys Ther, Epub 12 Sep 2018. doi:10.2519/jospt.2019.8375.

Perioperative Blood Flow Restriction Rehabilitation in Patients Undergoing ACL Reconstruction: A Systematic Review

“…59 However, multiple trials and several systematic reviews have supported the safety of BFR rehabilitation with regard to ischemic and hemostatic risks. § With the heterogeneity in quality of evidence, firm recommendations have been difficult to produce, 7,48 but a consensus among clinicians has pointed toward individualizing occlusion pressures, which has important implications for safety and effectiveness. 3,17,27,37,46,48,79 Currently, it is recommended that individual occlusion pressures be calculated as a percentage of the total arterial occlusion pressure (AOP), with individual protocols ranging from 60% to 80%.…”

The Safety of Blood Flow Restriction Training as a Therapeutic Intervention for Patients With Musculoskeletal Disorders: A Systematic Review

“…While adverse events may not be completely eliminated when the guidelines are followed, the risk of these adverse events may be greatly reduced when BFRT is prescribed according to established guidelines. 4…”

“…However, there are individuals utilizing BFRT without formalized training or by replacing pressure-adjustable cuffs with surgical tubing or elastic straps. 4 These more rudimentary methods may not completely occlude blood flow, and there is no way of knowing the occlusion pressure in the vessels. Given that there is not sufficient evidence to assess the safety of performing BFRT without formal training or using more rudimentary techniques to achieve occlusion, caution must be used in extending the results of this review to those scenarios.…”

“…Given that there is not sufficient evidence to assess the safety of performing BFRT without formal training or using more rudimentary techniques to achieve occlusion, caution must be used in extending the results of this review to those scenarios. Furthermore, as described by Bond et al, 4 cuff pressure prescription individualized to each patient seems to be the safest method allowing for proper progression of BFRT, as well as using cuffs that help disperse the occlusion pressure around the circumference of the given extremity. 4,57 By using devices and procedures designed for BFRT, it may be possible to enhance its safety and standardized use in clinical populations.…”

Intradialytic exercise with blood flow restriction is more effective than conventional exercise in improving walking endurance in hemodialysis patients: Response to comments on a randomized control trial

“…5 Even in this high-risk population, the reported incidence of adverse events associated with blood flow restriction is small and there is no formal contraindication for its practice. 6…”