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BackgroundPost-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis (DVT) that is characterised by chronic pain, swelling, and skin changes in the affected limb. One of every three people with DVT will develop post-thrombotic complications within five years. Several non-pharmaceutical measures are used for prevention of post-thrombotic syndrome during the acute phase of DVT. These include elevation of the legs and compression therapy. Clinicians and guidelines differ in their assessment of the utility of compression therapy for treatment of DVT. This is an update of a review first published in 2003.ObjectivesTo determine relative effectiveness and rate of complications when compression therapy is used in people with deep vein thrombosis (DVT) for prevention of post-thrombotic syndrome (PTS).Search methodsFor this update, the Cochrane Vascular Information Specialist (CIS) searched the Cochrane Vascular Specialised Register (20 March 2017) and CENTRAL (2017, Issue 2). The CIS also searched trial registries for details of ongoing or unpublished studies. SelectioncriteriaWe included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) of compression therapy, such as bandaging and elastic stockings, in people with clinically confirmed DVT. The primary outcome was the occurrence of PTS.Data collection and analysis Two review authors (DK and EvL) identified and assessed titles and abstracts for relevance, and a third review author (DA) verified this assessment independently. Review authors imposed no restrictions on date or language of publications. Three review authors (DA, DK, EvL) used data extraction sheets to independently extract study data. We resolved disagreements by discussion.Main resultsWe identified 10 RCTs with a total of 2361 participants that evaluated compression therapy. The overall methodological quality of these trials was low. We used only five studies in meta-analysis owing to differences in intervention types and lack of data. Three studies compared elastic compression stockings (pressure of 30 to 40 mmHg at the ankle) versus no intervention. Two studies compared elastic compression stockings (pressure 20 to 40 mmHg) versus placebo stockings. Overall, use of elastic compression stockings led to a clinically significant reduction in the incidence of PTS (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.38 to 1.01; P = 0.05; 1393 participants; 5 studies; low-quality evidence); no reduction in the incidence of severe PTS (RR 0.78, 95% CI 0.53 to 1.15; P = 0.21; 1224 participants; 4 studies; low-quality evidence); and no clear difference in DVT recurrence (RR 0.94, 95% CI 0.69 to 1.28; 1212 participants; 4 studies; P = 0.69; low-quality evidence). We did not pool data on the incidence of pulmonary embolism because this information was poorly reported, but we observed no differences between groups included in individual studies (low-quality evidence).Two studies evaluated effects of compression in the acute phase versus no compression treatment and found no differences in the incidence of PTS (RR 0.76, 95% CI 0.49 to 1.16; P = 0.2; 101 participants). One study reported that thigh-length stockings did not provide better protection against development of PTS than knee-length stockings (RR 0.92, 95% CI 0.66 to 1.28; P = 0.6; 267 participants). Another trial reported that wearing compression stockings for two years seemed to be superior to wearing them for one year in terms of PTS incidence.Two of the 10 included studies described patient satisfaction and quality of life (moderate-quality evidence), using different measurement systems. The first study showed significant improvement in well-being and DVT-related quality of life with compression treatment (P Authors'conclusionsLow-quality evidence suggests that elastic compression stockings may reduce the occurrence of PTS after DVT. We downgraded the quality of evidence owing to considerable heterogeneity between studies and lack of or unclear risk of blinding due to clinical assessment scores. No serious adverse effects occurred in these studies. Large randomised controlled trials are needed to confirm these findings because of current lack of high-quality evidence and considerable heterogeneity.

To investigate the effects induced by wearing an orthosis during the rehabilitation process, 23 ankle sprain patients (degrees I and II) were evaluated in three conditions (reference, with an elastic compression stocking and with an orthosis), 14 h, 10 and 30 days on average after their injury and compared with those of 30 age-matched healthy individuals. The patients were tested with separate measurements of the reaction forces under each limb to highlight the possible compensatory mechanisms between the sound and the injured legs. Their postural stability was enhanced during unilateral orthosis wear, explained by a bilateral effect involving both feet. Wearing a compression stocking induced comparably mild intermediate effects compared with the effects observed with the orthosis. These effects were constant throughout the next month. Following lateral ankle sprain, wearing an orthosis allows patients to improve postural function a few hours after the injury to 1 month later. Only cutaneous pressure intervening without mechanical maintenance induced mild effects, indicating that orthosis effects on postural control could partly result from its sensorial stimulation. It, therefore, seems relevant to prescribe orthosis wear for at least 1 month.

Combined micro- and mesoporous ZSM-5 zeolites with different mesopore sizes have been comparatively investigated using mercury-intrusion porosimetry (MIP) and N2 gas adsorption. N2 adsorption and MIP complement each other and a fairly good correlation has been obtained for the mesopore sizes and volumes derived from both techniques, confirming an adequate accessibility of the newly created mesoporosity. Elastic compression of the mesoporous zeolites during the mercury-intrusion experiments can account for the somewhat smaller average mesopore size and mesopore volume as derived from this technique. An excellent reproducibility of multiple mercury-intrusion cycles proves the mechanical stability of the hierarchical porous zeolites. Besides, MIP provides supplementary information on the presence of macropores.

Background/aims: Oedema is one of the most frequent signs of chronic venous insufficiency and may be present at all stages of this disorder. The aim of this study was to compare the effects of four different types of elastic compression stockings on oedema prevention in patients with varicose veins. Methods: An increase in foot volume after elevation of the leg was evaluated by strain gauge plethysmography in 20 limbs with varicose veins and 14 normal limbs, and the effects of four different compression stockings – 8, 14, 22 and 30–40 mmHg – were compared. Results: All stockings significantly reduced the foot volume increase compared with the no stockings patient group and the normal group. There was no significant difference in the volume increase in the normal group for all four stockings, while there was a significantly smaller volume increase in the 22 mmHg stocking compared to the 14 mmHg stocking in the patient group. Between the 22 mmHg and 30–40 mmHg stockings or between the 14 mmHg and 8 mmHg stockings, there was no significant difference in the volume increase. Conclusion: Elastic stockings, even with a pressure as low as 8 mmHg, can prevent oedema in patients with varicose veins, as well as in normal controls. However, the 22 mmHg and 30–40 mmHg stockings were better at preventing foot oedema in patients with varicose veins than those exerting less compression.

The aim of this work was to dynamically study pressure variations exerted by elastic compression stockings during walking. While study participants walked, the pressure variations at the interface between elastic stockings and the skin were measured dynamically. Three healthy individuals wearing 10/20 and 20/30 elastic compression stockings manufactured by Sigvaris((R)) (Jundiai, Sao Paulo-Brazil) were requested to walk along a course for ten times at a constant speed. For every event, an apparatus specifically developed for the study and programmed to take readings at half-second intervals was used to measure the pressure exerted by the elastic stockings. The pressure exerted by the 10/20 stockings varied between 5 and 32 mmHg and for the 20/30 stockings it varied from 10 to 52 mmHg. Elastic stockings with larger pressures generate larger pressure variations during muscle activity (P-value < 0.001). In conclusion, muscle movements during walking cause the pressure exerted by elastic stockings on the leg to vary; thus, the pressure is not constant but has peaks and troughs according to the type of muscle movement and the gradient of the stockings.

Post-thrombotic syndrome (PTS) is a potential complication following deep vein thrombosis (DVT) in children. Guidelines for management of PTS in children are non-existent. The absence of guidelines may limit the use of elastic compression stockings (ECS), offered for prevention and treatment of PTS in adults. We report the case of a 6-year-old, who developed PTS following a presumed line-related lower limb DVT, with dramatic improvement in functional status with ECS use. The presented case highlights the subtle nature of symptoms, potential benefits and limitations of ECS use for PTS, and current lack of evidence in children.

A comprehensive study of the molecular orientation and crystalline texture (the latter by low-angle x-ray diffraction supplemented by swelling measurements) in doubly oriented polyethylene on consecutive stages of heat annealing has allowed a picture of the structure and reorientation processes to be outlined. Thus even a drawn and rolled branched polyethylene is found to contain lamellae having {h0l}s basal planes with obliquities of 35–45°, in close analogy to those found in crystals grown from dilute solution and extracted from unoriented bulk linear polyethylenes. The initial ranges of the relaxation can be described by consecutive interlamellar and intralamellar slips activated by a rubber elastic compression. The cohesion between the lamellae opposing this is also found to be partially rubber elastic, and it is demonstrated that the resultant of the two elastic forces can be shifted by physical and chemical means. The individuality of the lamellae—requiring an appreciable amount of chain folding—is borne out. The possibility of producing macroscopic single-crystal analogs is also demonstrated.