Guideline Development Group

Summary of Evidence

Approximately one in three patients with LE DVT will experience PTS within five years and in 5-10% of these patients, PTS occurs in its most severe form as venous ulceration.^{12, 110, 111} The potential exists that should infection develop, septicemia and/or septic shock could result.¹¹² Patients with PTS experience chronic complaints of leg pain secondary to the DVT which may include the sense of the leg feeling heavy, cramping, itching, and in severe cases, venous ulceration.^{12, 97, 113} The pathogenesis of PTS is thought to be related to venous hypertension. As the thrombus initiates an inflammatory response, venous valves may become damaged during this process of thrombus resolution which is often incomplete over time. The damaged venous valves cause valvular reflux and as remodeling of the vein wall occurs, they may become stiff and contribute to increased outflow resistance which increases blood pressure in the veins. This increase in transluminal pressure causes leakage into the interstitial space leading to edema and skin changes. Microcirculation and blood supply to the leg muscles becomes compromised, which can lead to venous ulcerations in the more severe instances of PTS.⁹⁷ With clinical findings of PTS being similar to that of an acute LE DVT, concern is raised regarding the negative impact that PTS may have on a person’s quality of life experience^{12, 110, 112, 114-116}. For reasons described above, physical therapists should consider screening all patients with a history of LE DVT, past and current, for signs and symptoms of PTS. Once PTS is suspected, a specific and sensitive rating instrument referred to as the Villalta scale can be used to grade the severity of PTS.^{118, 119},^{116, 117}

A meta-analysis conducted on 5 RCTs, determined that venous compression stockings or compression bandages are effective in reducing PTS in patients.¹¹⁸ In patients receiving GCS with LE DVT compared to controls, mild-to-moderate PTS occurred in 64 of 296 (22%) treated with venous compression, compared with 106 of 284 (37%) in controls. Severe PTS occurred in 14 of 296 (5%) treated, compared with 33 of 284 (12%) controls. Development of any degree of PTS occurred in 89 of 338 (26%) treated, compared with 150 of 324 (46%). Thus, GCS reduces the severity of PTS although there was a wide variation in the type of stockings used, time interval from diagnosis to application of stockings, and duration of treatment.

Two Cochrane reviews, separated by one year, were conducted to determine the treatment interventions of IPC or GCS according to PTS severity. Findings from the first review based on two RCTs¹¹¹ included favorable trends using higher pressures of IPC over that of lower pressures and that there was not enough evidence to support the use of elastic GCS (30-40 mmHg pressures at the ankle versus placebo stockings) in patients having mild to moderate PTS severity. The second review based on three RCTs¹¹⁹ provided statistically significant evidence that elastic GCS of 20-40 mmHg interface pressure at the ankle reduce the severity of PTS after LE DVT.

A separate RCT involving 169 patients with a first or recurrent proximal LE DVT after receiving 6 months of standard treatment to wear GCS or not was conducted. ¹²⁰ The incidence of PTS was 11 patients (13.1%) in the treatment group compared with 17 (20.0%) in the control group. No venous ulceration was observed in either group with symptom relief significantly in favor of compression treatment during the first year but not thereafter. The conclusion reached was that prolonged use of GCS after proximal deep vein thrombosis significantly reduces symptoms and signs of post-thrombotic skin changes.

In the evidence-based guideline by the Finnish Medical Society Duodecim, immediate bandaging for compression during the acute phase of DVT (up to the groin if needed) is recommended in circular rather than figure eight turns.³⁰ In addition, the patient should be mobilized as soon as clinically possible, and GCS (Class II compression) should be worn for at least two years.

Pooled results from 4 RCTs in another Systematic review¹²¹ in patients with confirmed proximal LE DVT, used compression bandaging (inelastic or elastic) with or without early ambulation, as an intervention for PTS.¹²¹ Results stressed the importance of activating the calf muscle pump (CMP) in addition to compression bandaging, a message echoed by others more recently.¹²²

The lack of uniformity in reporting standards, such as the timing, duration, degree of compression interface pressure, among other descriptors, makes it difficult for meaningful comparisons between studies. This concern has been raised by more than one investigative group.^{97, 121-124}

In summary, mechanical compression (e.g. with IPC or compression bandaging and/or activation of the CMP), with or without ambulation, is the cornerstone in the treatment of PTS. The intervention strategy is primarily focused on decreasing venous pressure in the involved lower extremity, enhancement of the microcirculation, and reduction of the edema. The efficacy in treating PTS after confirmed acute LE DVT, its development during the sub-acute period, or as a debilitating chronic condition thereafter, does favor the early application and prolonged use of mechanical compression. The lack in uniformity of the methods and prescriptive protocols followed in the use of mechanical compression lends itself to controversy. Nevertheless, the preponderance of quality evidence does warrant a strong recommendation.