Guideline Development Group

Summary of Evidence

In the 9^th edition (2012) CPG by the ACCP, recommendations pertaining to mechanical compression based on moderate quality data for patients with diagnosed LE DVT were given.⁹⁰ For patients with acute symptomatic LE DVT and in those having PTS, graduated compression stockings (GCS) were suggested based on studies using at least 30 mmHg pressure at the ankle; in patients with severe PTS of the leg not adequately relieved with GCS, a trial with IPC was suggested.

Systematic reviews pertaining to the adjuvant use of mechanical compression

garments for anti-coagulated patients having acute VTE (e.g. LE DVT) while on bed rest or with early ambulation compared to controls provide supportive evidence for their use.⁹¹ The seven RCTs in these reviews concluded that mechanical compression lowered the relative risk for progression of a thrombus or the development of a new thrombus.

Two earlier RCTs conducted on patients over 2 years who had symptomatic, first

occurrence proximal LE DVTs, concluded that knee-length elastic GCS with interface pressures of 30-40 mmHg at the ankle reduced the incidence of mild, moderate, and severe PTS compared to controls who did not wear GCS.^{92, 93} In stark contrast, a more recent randomized placebo-controlled multi-center trial with 410 patients having a first proximal LE DVT followed for 2 years (i.e. SOX trial) did not support the routine wearing of GCS (i.e. knee length at 30-40 mmHg compared to < 5 mmHg placebo knee- length stockings) after LE DVT.⁹⁴

Two additional RCTs^{95, 96} on anti-coagulated patients having acute LE DVT combined early ambulation with the wearing of either inelastic-rigid stockings above the knee (i.e. zinc plaster UNNA boots providing 50 mmHg interface pressure at the ankle) or thigh-length elastic stockings (i.e. providing an interface pressure of 30 mmHg at the ankle) compared to control patients on bed rest. The combination of GCS with ambulation resulted in a faster resolution of pain and swelling, an increased quality of life outcome measure (by questionnaire).

In summary, the evidence to support mechanical compression methods as effective treatment interventions for secondary VTE prevention varies according to patient VTE risk profile, acute (e.g. hemodynamic stability) versus chronic (e.g. post-thrombotic syndrome concern) status, degree of signs (e.g. swelling) and symptoms (e.g. pain), as well as consideration for potentially harmful outcomes (e.g. skin lesions). Whether used adjunctively along with anticoagulants, alone as in patients when anticoagulant use is contraindicated, or in combination (e.g. ambulation plus GCS) with or without anticoagulation, mechanical compression use has mostly been favorable. Controversy persists, however, whether to support the routine use of mechanical compression (e.g. GCS) for LE DVT management and secondary prevention. Studies do tend to suggest that having GCS compression forces at the ankle, whether elastic or rigid, is beneficial when greater than or equal to 30 mmHg, especially when combined with early ambulation. Whether the mode of mechanical compression is by GCS and/or another (e.g. IPC), the optimal mechanical compression treatment strategy has yet to be identified.⁹⁷