Black holes in compression therapy: A quest for data

Abstract

Objective

Although compression therapy (CT) is considered a crucial conservative treatment in chronic venous disease, strong evidence is missing for many clinical indications. This literature review aims to point out what strong evidence we have for CT and all the clinical scenarios where strong evidence still needs to be included.

Methods

The research was conducted on MEDLINE with PubMed, Scopus and Web of Science. The time range was set between January 1980 and October 2022. Only articles in English were included.

Results

The main problem with CT is the low scientific quality of many studies on compression. Consequently, we have robust data on the effectiveness of CT only for advanced venous insufficiency (C3-C6), deep vein thrombosis and lymphedema. We have data on the efficacy of compression for venous symptoms control and in sports recovery, but the low quality of studies cannot result in a strong recommendation. For compression in postvenous procedures, superficial venous thrombosis, thromboprophylaxis, post-thrombotic syndrome prevention and treatment, and sports performance, we have either no data or very debated data not allowing any recommendation.

Conclusions

We need high-level scientific studies to assess if CT can be effective or definitely ineffective in the clinical indications where we still have a paucity of or contrasting data.

Compression therapy (CT) is one of the most effective conservative treatments for lymphatic and chronic venous disease (CVD). Many publications report its effectiveness, unfortunately often burdened with many methodological flaws leading to a low scientific level and resulting in scarce or no evidence. Critical issues concerning CT include not only a lack of reliable scientific data in many clinical indications, but also poor education in applying compression devices, especially relating to inelastic bandages (IBs), and a lack of compression devices easy to use by the health care professionals and by the patients themselves so to allow self-management and to increase compliance. This literature review aims to find the areas where data on the effectiveness of CT exist and areas where they are missing, scarce, or still debated.

Methods

Our literature research was conducted on MEDLINE with PubMed, Scopus and Web of Science. Keywords were selected using PubMed's medical subject headings (MeSH) and MeSH/EMTREE for Scopus. The keywords ‘chronic venous disease,’ ‘chronic venous; insufficiency,’ ‘spyder veins,’ ‘varicose vein,’ ‘leg edema,’ ‘lipodermatosclerosis,’ ‘healed ulcers,’ ‘venous leg ulcer,’ ‘superficial venous thrombosis,’ ‘deep venous thrombosis,’ ‘post thrombotic syndrome,’ ‘compression post venous procedures,’ ‘lymphedema,’ ‘medical compression stockings,’ ‘inelastic bandages,’ and ‘adjustable compression wraps’ were combined to obtain the pool of articles of interest. Inclusion criteria were papers published in peer-reviewed journals between January 1980 and October 2022; only papers in English were included.

Exclusion criteria included abstract conference and in vitro and ex vivo studies, and providing clinical and subjective outcomes. The reference list of selected studies was screened for further relevant publications. Studies on intermittent pneumatic compression were excluded (Fig).

Fig.

PRISMA flow diagram of relevant literature identified.

Results

CT in C0s to C2_S We have studies proving the effectiveness of CT by medical compression stockings (MCSs) exerting 15 to 20 mm Hg in relieving symptoms such as aching, pain, leg cramps, heaviness, tenderness, and restlessness and in improving quality of life (QoL) in healthy people, in patients in C0s and in the early stages of CVD (C1s-C2s).1, 2, 3, 4, 5, 6, 7 Nevertheless, a Cochrane review⁸ raises doubts about the scientific appropriateness of many studies in patients with symptomatic varicose veins. The review includes 13 studies where MCSs were applied in 1021 patients with varicose veins. The authors report (1) inconsistent selection of patients, (2) extreme variability in MCSs prescription, (3) different study protocols, and (4) risk of bias. In addition, comorbidities are often neglected, leading to uneven case series. In conclusion, despite the beneficial effect of MCS on symptoms due to varicose veins reported by all studies, many methodological flaws led the review authors to the following frustrating conclusions: “The certainty of the evidence was therefore low to very low” and “There is insufficient high-certainty evidence to determine whether or not compression stockings are effective as the sole and initial treatment of varicose veins …, or whether any type of stocking is superior to any other type.” Finally, the authors recommend new high-quality studies.⁸ This means that no substantial evidence supports the prescription of MCS in symptomatic patients in the initial stages of CVD and that new studies avoiding methodological flaws are necessary. Clinical guidelines provide us with a snapshot of these contrasting data. The American Guidelines⁹ “suggest” MCS in symptomatic varicose veins with a low grade of recommendation and evidence (Level of Evidence II, Grade C). The European guidelines¹⁰ recommend MCSs with strong grade and evidence (Level of Evidence, I, Grade B).

CT in C3 disease

Leg edema can occur in patients with venous insufficiency and in normal subjects standing or sitting all day for work reasons (the so-called occupational edema that disappears during landing and activity recovery). MSCs in the range of 10 to 20 mm Hg are effective in prevent long-haul flight11, 12, 13 and occupational edema.14, 15, 16, 17, 18, 19 Compression by IBs, MCSs, and adjustable compression wraps with a compression pressure of 20 to 40 mm Hg are necessary to treat venous edema,20, 21, 22 heart failure-related edema (with the exclusion of patients in class IV of New York Heart Association),^23,24 and in edema in diabetic patients.^25,26

CT in C4 disease

We have some studies supporting the use of MCS in patients with lipodermatosclerosis.27, 28, 29, 30, 31, 32 A compression pressure of approximately 40 mm Hg is necessary to decrease sclerotic areas,^27,28 whereas a lower pressure of 18 to 36 mm Hg is enough to remove tissue fluid.³¹ CT in C5 MSCs are effective in preventing ulcer recurrence. The higher the compression pressure, the better the prevention effect. Indeed, MCS exerting a compression pressure of 25 to 35 mm Hg had a more significant impact than MCS exerting 15 to 24 mm Hg.^33,34 Compliance must be considered and seems to exert an even more substantial role than compression pressure. In conclusion, the authors recommend prescribing MCS with the highest pressure tolerated by the patient.³⁵

CT in C6 disease

CT is one of the cornerstones of venous leg ulcer (VLU) treatment, strongly recommended in the most recent guidelines and consensus papers.^9,10,36, 37, 38 It is quite surprising that a recent review is more cautious regarding the remarkable effectiveness of CT in VLU management.³⁹ The authors conclude that leg ulcers probably heal more quickly when treated by CT and that CT probably reduces pain and may improve QoL. In the authors' opinion, the main weak points of considered studies are risk of bias, small patient numbers, variability of ulcer sizes and durations, significant number of used compression devices, and very low-certainty evidence on the cost-effectiveness of compression. Aside from the very subjective "uncertainties" of these authors on CT effectiveness, CT remains a fundamental therapeutic procedure in VLU management.^9,10,36, 37, 38 We do not yet know the optimal treatment for VLU in terms of compression devices and exerted pressure. We have data that IBs are more effective than elastic bandages in improving impaired venous hemodynamics.40, 41, 42, 43 They should be more effective in increasing the healing rate of VLU owing to a hemodynamic impairment. In addition, it is well-known that the higher the pressure, the higher the healing rate,⁴⁴ which should favor inelastic material, exerting a much higher standing pressure than elastic material. Studies are reporting greater effectiveness with IBs over elastic material.45, 46, 47 Nevertheless, some studies claim better effectiveness on the healing rate of MCSs^48,49 or elastic bandages⁵⁰ than inelastic materials. Two studies report similar effectiveness of elastic and inelastic compression on ulcer healing.^51,52 Finally, multicomponent bandages are reported as the best treatment modality in VLU by a previous Cochrane review “provided one layer is elastic.”⁵³ The papers comparing elastic and inelastic materials have many methodological flaws, the two major being the lack of compression pressure and stiffness assessment and the lack of education in applying IBs.⁵⁴ Compression pressure is the dosage of compression. When not measured, it is impossible to know if the compression material was applied correctly and if it exerts the pressure required to promote ulcer healing. By using MCS, we approximately know their pressure as guaranteed by the manufacturers, even if the exerted pressure does not always correspond with the pressure declared by the manufacturer.⁵⁵ Quite the opposite, it is well-known that IBs are usually poorly applied.56, 57, 58, 59, 60 In one study,⁵⁶ the authors showed that, even when given expert nurses routinely applied IBs in patients with ulcers, the same IB, exerting a pressure of 50 to 60 mm Hg when correctly wrapped, was applied with a pressure ranging from a few mm Hg to >140 mm Hg. These studies raise doubts about the conclusions of comparative papers not reporting compression pressure. In one of the very few studies where the authors measured the compression pressure, the IB was so poorly applied that its pressure was lower than that of an elastic kit used as a comparator.⁶¹ The authors concluded that the elastic kit was more effective than the IB. It would be better to state that “an effective elastic kit was superior to a very poorly applied IB.” Furthermore, without measuring compression pressure it is impossible to assess the stiffness of the applied compression, which led many authors to the dogmatic conclusion that the so-called four-layer bandage is elastic only because it is made up of four elastic bandages. When the four-layer bandage is applied, it becomes inelastic, possibly owing to the friction between different layers.⁶² Comparing an IB with the four-layer, two IBs were compared, making the conclusion of these studies hard to accept. The conclusion of the Cochrane review,⁵³ based on these studies, is hard to get, too. However, hard to believe, we currently miss high-quality studies comparing elastic and inelastic material for ulcer healing and showing which is the best treatment option. The decision on what material to use is left to the individual preference of doctors or nurses.

CT to prevent venous disease progression

We lack data to recommend CT to prevent venous disease progression. There is only a tiny study⁶³ reporting the effectiveness of MCS in progression prevention, but this is not confirmed by other studies.⁶⁴

CT after venous procedures

CT after venous procedures is one of the most debated issues in CT. The rationale for applying CT after venous procedures is minimizing or preventing side effects, such as pain, inflammation, bleeding, hematoma, bruising, and superficial or deep vein thrombosis (DVT) by compressing the treated vein (after endovenous procedures) or the removed vein track (after vein stripping or phlebectomies). Also, prevention of varicose veins recurrence after vein stripping was reported.⁶⁵ In this field we have many papers in favor of the beneficial effect of CT, by strong66, 67, 68, 69, 70 or light71, 72, 73, 74, 75 pressure and many other reporting that CT after venous procedures is useless.76, 77, 78, 79, 80 In one systematic review, it was reported that the routine use of CT after thermal ablation of varicose veins was effective in decreasing postoperative pain and the time to return to normal activities.⁷⁴ Once again, the conclusion of this paper is opposite to the conclusion of another systematic review,⁸⁰ increasing the uncertainty as to whether CT is effective or not after thermal ablation of varicose veins. The only general agreement regarding vein stripping or phlebectomies where CT is generally recommended.81, 82, 83 These conflicting data are reflected in one recent consensus paper⁸⁴ and in one guideline,¹⁰ suggesting CT after vein procedures with very low evidence, although CT is strongly recommended in another consensus paper.⁸⁵ All these discrepancies could be caused by some methodological flaws in many of these papers. The sample size is often inadequate to get a statistically significant difference between different compression modalities or between compression and no compression. Compression pressure was rarely measured and, when measured, firm compression showed to reduce postoperative side effects more effectively than light compression in decreasing postoperative side effects.66, 67, 68, 69, 70 Furthermore, compression pressure exerted by MCS at thigh level is hardly >10 mm Hg, much lower than the 40 mm Hg necessary to occlude the veins at the thigh level.⁸⁶ Many studies comparing MCS and no compression actually compared no compression and no compression, making the conclusions difficult to accept. Vein diameter is never mentioned, but it has been reported that the recanalization rate and side effects are much higher when treating large veins than small veins.87, 88, 89 Finally, noncompliant patients are included in the final analysis,⁷⁶ when they should be excluded. The same contrasting data regard the optimal duration of compression, with some papers reporting a short time of 3 days as enough to control side effects^81,90 and another reporting that a period of 1 to 2 weeks is more effective than a shorter time.⁹¹ A >7 days does not increase the effectiveness in reducing the unwanted effects.⁹² In conclusion, we can sadly state that we do not know if CT is helpful after venous procedures or what its optimal duration is.

CT in superficial vein thrombosis

Studies on CT as the sole treatment of superficial vein thrombosis (SVT) do not exist because CT is always associated with antithrombotic and anticoagulant therapy. One consensus document recommends CT as an effective treatment in addition to antithrombotic therapy.⁹³ Another study⁹⁴ reports that compression does not add any advantage to the antithrombotic treatment concerning the reduction of pain, consumption of analgesics, thrombus length, skin erythema, d-dimer, or QoL. However, MCS stimulated significantly faster thrombus regression after 7 days of wear. In the most recent guidelines on the management of venous thrombosis, CT is not even mentioned in the treatment of SVT.⁹⁵ In conclusion, we need to learn more about the effectiveness of CT in SVT treatment. When CT is prescribed, we do not have data on how long it must be used, although also this is a piece of vital information to get.

CT in thromboprophylaxis

The rationale of CT in bedridden patients to prevent DVT is compressing the veins,96, 97, 98 increasing the venous blood velocity,⁹⁹ and so minimizing venous stasis. Whatever the involved mechanism, MCSs were very effective in DVT prevention in surgical patients as a unique treatment and combined with other therapeutical interventions.¹⁰⁰ Several papers confirmed the MCS effectiveness in this field,101, 102, 103 and these positive reports were reflected in a Cochrane review.¹⁰⁴ MSCs were reported to be effective also in decreasing the incidence of asymptomatic DVT in addition to reducing leg edema and SVT in airline passengers.¹⁰⁵ Recent studies comparing MCS alone with pharmacological thromboprophylaxis plus MCS in surgical patients and in patients undergoing knee arthroscopy did not report any advantage of the additional MCS compared with pharmacological thromboprophylaxis alone.106, 107, 108 As one of these studies¹⁰⁶ highlights, “further studies are required to evaluate whether or not adjuvant graduated compression stockings have a role in patients receiving extended thromboprophylaxis, beyond the period of hospital admission, following elective surgery or in patients undergoing emergency surgical procedures.”

Furthermore, thigh-length MCSs are ineffective in preventing DVT in stroke patients,¹⁰⁹ even if this result is unclear. The same authors in the following paper conclude that thigh-length MCSs are more effective than knee-length MCS in DVT¹¹⁰ prevention, making their first conclusion difficult to understand.¹¹¹ In no study concerning surgical and medical patients was the duration of immobility reported; however, this information should be known as well.

CT in DVT treatment

In the acute phase of DVT, CT counteracts the increased venous pressure in the leg and improves venous flow. In this way, CT can decrease edema and pain owing to the deep vein obstruction and its associated inflammatory response.^112,113 Compression immediately after DVT diagnosis was reported to prevent irreversible skin sign¹¹⁴ and venous occlusion.¹¹⁵ Flow restoration is essential to promote impaired thrombus resolution under low-flow conditions.¹¹⁶ In clinical practice, initial compression is applied by multilayer IB or by MCS. When IBs represent the initial treatment, MCSs are prescribed when the edema has resolved. The importance of immediate compression for a favorable outcome of DVT, including improved QoL and a positive influence on recanalization, has been well-established.112, 113, 114, 115, 116, 117, 118, 119, 120 Consequently, immediate CT after the diagnosis of DVT is broadly used worldwide¹²¹ and strongly recommended in the recent guideline on venous thrombosis.⁹⁵ New studies are necessary to clarify the optimal compression device immediately after DVT diagnosis, the optimal compression pressure, and optimal length.

CT in the prevention of post-thrombotic syndrome

Another very debated topic regarding CT. Many data from past studies report the beneficial effects of compression in preventing post-thrombotic syndrome (PTS).122, 123, 124, 125, 126 The guideline reflected the widespread belief in compression's effectiveness in preventing PTS with a strong recommendation.¹²⁷ Afterward, a new study comparing class III MCS and placebo stockings in patients with acute DVT proved that MCSs are ineffective in PTS prevention, because it occurred in about the same percentage of patients wearing MCS or placebo stockings.¹²⁸ Despite many methodological flaws,^15,129 this study raised many doubts about the actual effectiveness of MCS in preventing PTS and was followed by another study arriving at the same conclusion.¹³⁰ In addition, different meta-analyses reflects these contrasting data, with one favoring CT to prevent PTS¹³¹ and one against it.¹³² In new guidelines and meta-analyses, MCS are not longer recommended, but only suggested with low-quality evidence.^95,133 New studies on CT applied immediately after DVT diagnosis¹¹⁵ and continued for ≥6 months¹³⁴ confirm the compression effectiveness in PTS prevention. In another study, MCSs effectively prevented PTS, even in patients with proximal DVT without thrombus removal.¹³⁵

In a recent study in patients with proximal DVT, MCSs were reported as significantly effective in PTS prevention in patients with residual venous obstruction. In patients without venous obstruction, the MCSs were slightly but not significantly more effective.¹³⁶ In conclusion, in this field, we miss reliable and consistent data owing to study cohort variability, which has created a wide range of study results.

CT in PTS treatment

PTS is characterized by symptoms and signs typical of CVD. Feelings of leg heaviness, tiredness, and pain increasing throughout the day, aggravated by standing or walking and improved by rest and leg elevation, are common. The typical signs are edema, redness, and eventually lipodermatosclerosis and ulcers in severe cases. Amazingly, CT improves all these symptoms and signs,3, 4, 5, 6, 7 but it seems to be ineffective when the same symptoms and signs are caused by PTS. We have only three small studies on MCS in PTS treatment.^123,137,138 Two studies reported no benefit of compression over no compression.^123,137 The third study,¹³⁸ focused on the effects of MCSs on venous hemodynamics as assessed by air plethysmography, did not consider the symptoms and signs of PTS.

Lymphedema

CT is part of a more complex therapeutical strategy for lymphedema: complex decongestive therapy, including skin care, physical activity, manual lymphatic drainage, and CT.139, 140, 141, 142, 143, 144 It is not easy to find a publication on lymphedema therapy where CT is the sole treatment. Also, clear recommendations from guidelines are missing.¹⁴⁵ In this field, routine clinical treatment was established and reported in the consensus documents. In the initial phase, the so-called treatment stage, CT, by multilayer, multicomponent IBs, is applied together with the mentioned treatments.139, 140, 141, 142, 143, 144

Adjustable compression wraps—special inelastic compression devices with Velcro closure—are an effective treatment alternative to IB.¹⁴⁶ As soon as edema has been removed, a particular type of MCS—flat-knitted compression stockings—is applied. These stockings are particularly indicated for the maintenance phase of lymphedema when it is necessary to maintain the result and prevent edema recurrence. In some studies, CT started with compression hosiery, skipping the initial phase with multicomponent IBs. When two treatment modalities, one beginning with MCS and the other with IBs followed by MCS, were compared, this second option proved more effective in reducing arm lymphedema.^147,148 Even if clear evidence as isolated treatment is missing, CT included in the complex decongestive therapy proved to be a very effective therapeutical modality in lymphedema. Its effectiveness does not need to be demonstrated further.

CT and sport

Compression during or after sport does not represent a clinical indication but, it is a very debated topic and deserves to be mentioned in this review. Compression by specifically designed elastic stockings has spread over the years in several sports activities.

Compression during or after sport is applied to increase the sport's performance and benefit recovery. Even in this field, the effectiveness of compression is very debated. Studies usually include a small sample size; there is a lack of homogeneity owing to the use of different stockings in different sports, the level of sports participants (if professionals or only passionate), when and how long the stockings were worn, and the variety of sports socks regarding exerted pressure and pressure profile (graduated or progressive). In addition, sports and industry lobbies may have influenced some publications with a high biases risk and conflicts of interest.¹⁴⁹ Regarding performance increase by compression, some studies report beneficial effects,^150,151 whereas others, without biases, raise many doubts.¹⁵² Many studies report positive effects in recovery time^153,154 without influencing the next sports performance.¹⁵⁵ There are also sparse data on reduced exercise-associated hemostatic activation decreasing the DVT risk during prolonged exercise¹⁵⁶ and on reduced perceived fatigue.¹⁵⁷ In this field, future studies are mandatory to confirm whether compression effectively improves recovery after sport or enhances sports performance. The beneficial effects of compression in athletes with varicose veins should be addressed as well. No study considered athletes with varicose veins, but many athletes with varicose veins ask about their disease and sport!

Lack of education resulting in poor patient compliance

IBs are challenging to apply and require education. Some papers52, 53, 54, 55, 56 report that many health care professionals cannot apply IB with proper pressure. The pressure can be too low and ineffective or too strong, resulting in painful and potentially dangerous compression. Even with MCS, prescription mistakes regarding size and compression pressure can be made.158, 159, 160, 161, 162 The lack of education in CT application or prescription can be a reason for noncompliance because the patients can find no benefit from compression or find it painful and harmful. Compression wraps represent a new compression modality. A short education time for the patient can be enough to apply the device properly.¹⁴⁶ Even with these devices, special care for a proper prescription is necessary.¹⁶³

Discussion

This literature revision shows that arguments favoring CT are weak, vague, nonexistent, or contrasting in disease progression prevention,^63,64 C0s, early-stage CVD (C1s-C2s),^8,9 venous postprocedures,65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80 superficial venous thrombosis,93, 94, 95 thromboprophylaxis in surgical patients,106, 107, 108, 109, 110, 111 PTS prevention,^15,128, 129, 130^,132 PTS treatment,^123,137,138 and during or after sports149, 150, 151, 152, 153, 154, 155, 156, 157 (Table). Only a few medical indications for CT are endorsed by evidence-based medicine: in the more advanced stages of CVD (C3-C5),11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 in VLUs,38, 39, 40, 41, 42, 43, 44, 45, 46, 47 after venous stripping,81, 82, 83 in DVT treatment,112, 113, 114, 115, 116, 117, 118, 119, 120, 121 and in lymphedema treatment and prevention.139, 140, 141, 142, 143, 144, 145 In VLU and DVT treatment, it is necessary to clarify whether inelastic compression is the most effective treatment modality or if MCSs can be enough. The lack of data leads to an uncommon situation. On one side are health care providers familiar with CT, who know its effectiveness and apply CT in several clinical scenarios of CVD, even when strong indications are missing.164, 165, 166, 167, 168, 169, 170, 171, 172, 173 On the other side is a vast group of people (nurses and doctors, national health systems, and insurance company personnel) not specifically interested and lacking knowledge about the merits of an effective CT, who are reluctant to apply CT, even in areas where it could benefit patients. The main problem with CT is the low scientific level of many reported studies.

Table.

Available data in favor of compression therapy (CT) use in different clinical indications

	Strong indications for usea	Weak indications for useb	No or contrasting indications for usec
C0s-C2s		√
C3-C5	√
C6	√
C6 (elastic/inelastic material)			√
Prevention of CVD progression			√
CT after venous procedures			√
SVT			√
Thromboprophylaxis			√
DVT	√
DVT (elastic/inelastic material)			√
PTS prevention			√
PTS treatment			√
Lymphedema	√
Sport performance			√
Sport recovery			√

^aCT is effective. Data coming from a full agreement of published studies.

^bCT is effective. Data coming from low quality scientific studies according to Cochrane review.¹⁰

^cCT is effective? No or contrasting data regarding CT effectiveness.

The list of methodological flaws is impressively long: small, underpowered studies unable to demonstrate a significant difference between treatments, inconsistent selection of patients, lack of a control group, incorrect randomization, lack of double blindness, extreme variability in CT prescription, totally different study protocols, a lack of pressure measurement and stiffness assessment, making impossible to recognize the different effects of various compression modalities, extremely variable time of application, often not specified, and risk of bias. Finally, compliance is rarely considered and reported. When reported, compliance is frequently very low.^76,128 Amazingly, noncompliant patients are included in the statistical analyses and final results, making the conclusions completely unrealistic; these patients should be excluded, as in all other fields of medicine.

All these methodological flaws make it possible to arrive at different and sometimes opposite conclusions. A good example is represented by CT after venous procedures where, owing to opposing data coming from different studies, we still do not know if compression is effective in preventing unwanted effects or totally useless. As a consequence of these confusing data, it also happened that even different guidelines suggest with low level of evidence or strongly recommend CT for the same indication. For instance, CT in symptomatic varicose veins is suggested with a low level of evidence (2C) by American Venous Forum-Society for Vascular Surgery guidelines⁹ and strongly recommended (1B) by European Society for Vascular Surgery guidelines.¹⁰ The same is true for other indications, raising the question of what kind of decision it is possible to take, looking at guidelines, if they give us different indications and what guideline we must refer to in our clinical practice. This is why we are strongly convinced that new high-quality studies on CT are necessary. As general recommendations, these new studies should be appropriately powered to demonstrate a significant difference between treatments, the selection of patients and randomization must be correctly performed, a control group is mandatory, double blindness should be considered, and CT prescription and study protocols should be consistent. Noncompliant patients should be excluded from the results analyses. Specific recommendations should be added for specific studies. Finally, compression pressure, the most important parameter, the dosage of CT, must be measured and stiffness assessed by stiffness indices to ensure a correct and consistent compression device application.

An effective system to increase the reliability of studies on CT, certainly able to significantly improve their scientific quality, would be the use of specific sensors. Sensors measuring pressure, position and mobility under compression devices could be helpful. They could provide us with information not only on pressure and stiffness but also on compliance of patients (if the sensor does not record data, the patient is not wearing the prescribed compression) and on their daily activity (sitting, standing, walking, and lying time) that can make a tremendous difference in terms of outcomes. In this way, using sensors could eliminate the major methodological flaws in the studies on CT. Last but not least, clinical and QoL scores must be reported.

Conclusions

Our review highlights that we lack consistent data on CT effects in many clinical conditions and that work is necessary to fill the gaps in this critical treatment modality. As long as we cannot offer physicians and nurses, health care providers, national health systems, and insurance companies reliable scientific data regarding CT efficacy in the different indications, CT will remain an obscure treatment modality, underestimated or overestimated without strong clinical indications, and neither correctly used nor reimbursed.

Author Contributions

Conception and design: GM

Analysis and interpretation: GM, CW, AC

Data collection: GM

Writing the article: GM

Critical revision of the article: GM, CW, AC

Final approval of the article: GM, CW, AC

Statistical analysis: Not applicable

Obtained funding: Not applicable

Overall responsibility: GM

Disclosures

None.