BlueCross and BlueShield of Montana Medical Policy/Codes
Noncontact Wound Therapy
Chapter: Radiology
Current Effective Date: September 24, 2013
Original Effective Date: March 16, 2011
Publish Date: September 24, 2013
Revised Dates: December 5, 2012; August 28, 2013
Description

Normothermic Wound Therapy

An optimal environment for wound healing is thought to include a moist normothermic (normal body temperature) environment, enhancing the subcutaneous oxygen tension and increasing the blood flow to the wound.  A device called Warm-Up Active Wound Therapy®, approved by the United States Food and Drug Administration (FDA), attempts to create this environment.  The device includes a noncontact bandage and warming unit designed to maintain 100% relative humidity and to produce normothermia in the wound and surrounding tissues.  The bandage is composed of a sterile foam collar that adheres to the periwound (peripheral) skin, and a sterile transparent film that covers the top of the wound but does not touch it.  An infrared warming card is inserted into a pocket of the film covering.  Treatments are administered three times a day in one hour sessions.

Ultrasound (US) Wound Therapy

Low-frequency ultrasound (US) in the kiloherz range may improve wound healing.  Several devices are available; one example is the MIST Therapy® system, which delivers ultrasonic energy to wounds via a saline mist without direct skin contact.

US is defined as a mechanical vibration above the upper threshold of human hearing (>20 KHz).  US in the MHz range (1–3 MHz) has been used for the treatment of musculoskeletal disorders, primarily by physical therapists.  Although the exact mechanism underlying its clinical effects is not known, therapeutic US has been shown to have a variety of effects at a cellular level including angiogenesis; leukocyte adhesion; growth factor and collagen production; and increases in macrophage responsiveness, fibrinolysis, and nitric oxide levels.  More recently, the therapeutic effects of US energy in the kilohertz range have been examined.  It has been proposed that low frequency US in this range may improve wound healing via the production, vibration, and movement of micron-sized bubbles in the coupling medium and tissue.

The mechanical energy from US is typically transmitted to tissue through a coupling gel.  Several high-intensity US devices with contact probes are currently available for wound debridement.  A noncontact low-intensity US device has been developed that does not require use of a coupling gel or other direct contact.  The MIST Therapy™ System (Celleration) delivers a saline mist to the wound with low-frequency US (40 KHz); it includes a generator, a transducer, and a disposable applicator for discharge of prepackaged saline.

In 2004, the FDA reclassified these devices from class III to class II at the request of Celleration (K032378).  As part of the reclassification, the FDA named this type of device as a "low energy ultrasound wound cleaner" which they defined as “a device that uses ultrasound energy to vaporize a solution and generate a mist that is used for the cleaning and maintenance debridement of wounds.  Low levels of ultrasound energy may be carried to the wound by the saline mist.”  In 2005, the Celleration MIST therapy device received marketing clearance (K050129) through the FDA's 510(k) process, “to promote wound healing through wound cleansing and maintenance debridement by the removal of yellow slough, fibrin, tissue exudates and bacteria.”  Several wound drainage and wound vacuum systems were listed as predicate devices.

The FDA’s 510(k) process does not require data regarding clinical efficacy; this device was considered essentially equivalent to predicate powered suction pump devices based on the “use of mechanical energy to promote wound healing through means such as the removal of infectious material and other wound exudates.”

In 2007, the AR1000 Ultrasonic Wound Therapy System (Arobella Medical) received marketing clearance, listing the Celleration MIST system and several other ultrasonic wound debridement and hydrosurgery systems as predicate devices.  The AR1000 system uses a combination of irrigation and US with a contact probe to debride and cleanse wounds.  The indications are similar to that of the MIST system, listed as: “selective dissection and fragmentation of tissue, wound debridement (acute and chronic wounds, burns, diseased or necrotic tissue), and cleansing irrigation of the site for the removal of debris, exudates, fragments, and other matter.”

Policy

Investigational

Blue Cross and Blue Shield of Montana (BCBSMT) considers the use of noncontact normothermic wound therapy, either as a primary intervention or as an adjunct to other wound therapies, experimental, investigational and unproven. 

Ultrasound wound (US) therapy is considered experimental, investigational and unproven.

Rationale 

Normothermic Wound Therapy

Standard components of wound care include sharp debridement of devitalized tissue, infection control, non-weight bearing, and treatment of underlying co-morbidities, such as adequate nutrition or glycemic control in diabetics.  Therefore, validation of any adjunct to standard wound management requires a randomized controlled trial (RCT) to isolate the contribution of the intervention compared to underlying wound management.  A literature review identified one small, randomized crossover trial of warm-up active wound therapy involving 13 patients who were followed up for two weeks.  Compared to the control group, more patients in the treatment group improved (62.5% vs. 37.5%).  However, the term “improvement” was not fully defined, and no statistical analysis was provided.  Santilli and colleagues reported a two-week trial of warm-up active wound therapy in which 17 patients with 31 wounds served as their own control. Almost half of these patients, all refractory to prior therapy, reported complete healing within 12 weeks after treatment.  While studies of wound-healing therapies frequently use patients as their own control, this trial design cannot isolate the contribution of the intervention.  It is possible that the wound-healing effect may be in part due to increased attentiveness to underlying wound care rather than to the warm-up active wound therapy itself.  Finally, Cherry and Wilson reported on a case series of five patients who received a two-week trial of warm-up active wound therapy. Although four of the five patients reported complete healing at 6-14 weeks after treatment, a case series does not permit isolation of the contribution of the warm-up therapy.  In addition, both in this trial and in the previous trial reviewed, it should be noted that wound healing occurred several weeks after discontinuation of the warm-up therapy, further confounding any evaluation of the therapy.

In January 2002, the Centers for Medicare and Medicaid Services (CMS) published a review of the available literature of noncontact normothermic wound therapy, specifically literature focusing on the warm-up active wound therapy device.  CMS identified eight articles that met their selection criteria, including five randomized studies (two of which were not yet published) and three case series.  Data were separately analyzed for different types of wounds, i.e., pressure ulcers, venous stasis ulcers, diabetic/neuropathic ulcers, non-healing surgical incisions, and other types of chronic wounds.  The CMS review identified methodologic flaws in all the trials in ensuring standard wound care in all patients, reporting outcomes, or reporting statistical or clinical significance of outcomes.  The CMS assessment offered the following conclusion:

"In summary, the medical literature does not support a finding that noncontact normothermic wound therapy (NNWT) heals any wound type better than conventional treatment.  While the submitted studies purport better healing, due to serious methodologic weaknesses, inadequate controls, and a variety of biases, the improved outcomes could also easily disappear in a properly controlled randomized trial.  Furthermore, there is no reason why such a trial could not be readily performed.  A trial that would best answer our coverage concerns would be one in which there was randomization to three arms: 1) experimental arm which would receive NNWT; 2) experimental arm which would receive NNWT, but with the heating element turned off; and 3) control arm, which would only receive conventional therapy.  Conventional therapy should be standardized across all three arms as applicable."

Since the CMS decision, results from four small studies (ranging in size from 16–36 patients) were published that found increased wound healing time with use of noncontact normothermic wound therapy.  However, none of these studies was a controlled randomized, three-arm trial to isolate the effect of the intervention and address the trial design issues noted.  In addition, stratification of wound size, duration, and location are also necessary in trial design.

Alvarez et al. conducted a small (49 patients) open-label randomized trial with standard therapy controls.  The study found an improvement in wound healing with NNWT; at 12 weeks, 18% of NNWT wounds had complete healing compared to 9% in the control group.  However, as the authors noted, the three hours per day of off-loading (application for one hour three times per day), may have improved patient compliance to off-loading instructions.  A study in a larger patient population with the appropriate control groups, as described, is needed.

In summary, improved health outcomes have not been demonstrated with use of a noncontact radiant heat bandage.

2012 Update

A search of peer reviewed literature through February 2012 identified no new clinical trial publications or any additional information that would change the coverage position on the use of noncontact normothermic wound therapy.

Ultrasound (US) Wound Therapy 

One objective of this review is to evaluate whether the addition of noncontact US with saline mist improves wound healing in comparison with standard treatment alone.  Two industry-sponsored (RCT) s have assessed the incremental benefit of MIST therapy on wound healing.

One double-blind multicenter (RCT) used MIST therapy for recalcitrant diabetic foot ulcers.  Most of the 133 patients (85%) were enrolled and treated at 17 different wound clinics/private practice centers.  An additional 15% of patients were enrolled at six university medical clinics.  Patients with recalcitrant foot ulcers were treated with active or sham saline mist therapy three times per week, with debridement as needed and a weekly evaluation by an independent investigator.  Twenty-four patients were lost to follow-up, and data from 54 patients were excluded from analysis due to protocol violations (five centers were found to have inverted the treatment distances for the active and sham devices), leaving 55 patients (41%) for the per-protocol analysis.  The investigators reported significant improvement (11 of 27 patients [41%] versus 4 of 28 patients [14%]) in the proportion of wounds healed (defined as complete epithelialization without drainage).  However, intent-to-treat analysis showed no difference in wound healing (26% vs. 22%) between the active (n=70) and control (n= 63) groups.  In addition to the 59% loss to follow-up, there was a difference in the ulcer area at baseline (1.7 vs. 4.4 cm2) and chronicity of wounds (35 vs. 67 weeks) that favored MIST therapy in the per-protocol groups.  Due to the serious limitations of this study, these results are considered inconclusive.

Kavros et al. randomized 70 patients with nonhealing (two months) foot, ankle, or leg wounds to standard of care alone or standard of care plus MIST therapy for 12 weeks.  To participate, patients with documented ischemia (transcutaneous oximetry [TcPO2] of 40 mmHg or less) had to agree to three times per week visits for therapy.  This open-label (non-blinded) study found that a greater proportion of patients in the MIST therapy group (22 of 35, or 63%) achieved wound healing (defined as a reduction of wound area greater than 50%) in comparison with standard of care alone (10 of 35 or 29% of patients).  Control was not provided for non-specific effects of the additional treatment sessions.  In addition, although the study reported on the importance of baseline TcPO2 on wound healing, patients with low (1–20 mmHg) and high (21–40 mmHg) TcPO2 levels do not appear to be equally distributed between the groups.  In a retrospective analysis by Kavros and colleagues, wound healing in 163 patients treated with MIST therapy (three times per week for 90 days) was found to be 53%, compared with 32% from 47 matched controls treated during the same period who were unable to undergo three weekly visits.  Use of noncontact ultrasound for burns has been reported in small (14 patients or less) uncontrolled case series.

A new systematic review of all prospective studies comparing ultrasonic mist therapy only identified the two randomized trials already cited in the policy.  There was also a new retrospective chart review involving 76 patients.  Due to the lack of a comparison intervention, this article does not add to our understanding of the effectiveness of ultrasound therapy for wound healing; well-designed trials are still lacking.

2010 Update

A search of peer reviewed literature through January 2010 identified no new clinical trial publications or any additional information that would change the coverage position of this medical policy.

2012 Update

An industry-sponsored meta-analysis, published in 2011, identified 10 studies evaluating non-contact low-frequency US therapy for treating chronic wounds (Driver et al.).  To be eligible for inclusion in the meta-analysis, studies had to have at least four weeks of follow-up.  Two studies were excluded, one because data were not in a form suitable for pooling and the other because follow-up time was too short.  Of the remaining eight studies, one was an RCT, and the remainder were observational studies (five retrospective analyses and two prospective studies).  A pooled analysis of findings from seven studies (total n=429) found that a mean of 32.7% (95% confidence interval [CI]: 23.3% to 42.1%) of patients had healed wounds by a mean of six weeks.  A pooled analysis of four studies (total n=188) found a mean of 85.2% (95% CI: 64.7% to 97.6%) reduction in wound area by final follow-up.  The major limitation of this meta-analysis was that there were no pooled comparisons of non-contact US therapy to optimal wound care alone, or to an alternative intervention.  Thus conclusions cannot be drawn about the incremental benefit of non-contact ultrasound treatment over optimal wound care alone.

Other studies include a systematic review, published in 2008, that identified the two randomized trials described above and no additional studies.  Non-contact US for treating wounds has also been evaluated in case series, such as a retrospective chart review involving 76 patients. (Bell et al.)  In addition, use of non-contact ultrasound for burns has been reported in a small uncontrolled case series (Samies et al.).

In 2010, the Association for the Advancement of Wound Care (AAWC) published a guideline on care of pressure ulcers.  Non-contact ultrasound therapy was included as a potential second-line intervention if first-line treatments did not result in wound healing with a Level of Evidence C.

Summary

Currently available scientific evidence does not permit conclusions concerning the effect of this technology on health outcomes.  There are two RCTs that report benefits on some outcomes, but both trials have substantial methodologic flaws that limit the validity of the findings.  Well-designed, blinded studies that have adequate numbers of patients and that include all relevant outcomes are needed to further evaluate the efficacy of this treatment.  Therefore, non-contact ultrasound treatment for wounds is considered experimental, investigational and unproven.

Coding

Disclaimer for coding information on Medical Policies          

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy.  They may not be all-inclusive.           

The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers.  Only the written coverage position in a medical policy should be used for such determinations.           

Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps.

ICD-9 Codes

Experimental, investigational and unproven for all diagnoses.

ICD-10 Codes

Experimental, investigational and unproven for all diagnoses.

Procedural Codes: 0183T, A6000, E0231, E0232
References

Normothermic Wound Therapy

  1. Robinson, C., and S.M. Santilli.  Warm-Up Active Wound Therapy®: a novel approach to the management of chronic venous stasis ulcers.  Journal of Vascular Nursing (1998) 16(2):38-42.
  2. Santilli, S., and Valusek, P., et al.  Use of a noncontact radiant heat bandage for the treatment of chronic venous stases ulcers.  Advance Wound Care (1999 March) 12(2):89-93.
  3. Cherry, G.W., and J. Wilson.  The treatment of ambulatory venous ulcer patients with warming therapy.  Ostomy Wound Management (1999) 45(9):65-70.
  4. CMS – Medicare Coverage Database.  Normothermic Wound Therapy (NNWT). Centers for Medicare and Medicaid Services (2002 July 1) Durable Medical Equipment 270.2 (100-3):1. http://www cms.hhs.gov .
  5. McCulloch, J., and C. A. Knight.  Noncontact normothermic wound therapy and offloading in the treatment of neuropathic foot ulcers in patients with diabetes.  Ostomy Wound Management (2002) 48(3):38-44.
  6. Kloth, L., Berman, J., et al.  A randomized controlled clinical trial to evaluate the effects of noncontact normothermic wound therapy on chronic full-thickness pressure ulcers.  Advance Skin and Wound Care (2002 November-December) 15(6):270-6.
  7. Alvarez, O.M., Rogers, R.S., et al.  Effect of noncontact normothermic wound therapy on the healing of neuropathic (diabetic) food ulcers:  an interim analysis of 20 patients.  Journal of Foot and Ankle Surgery (2003) 42(1):30-5.
  8. Karr, J.C.  External thermoregulation of wounds associated with lower extremity osteomyelitis.  A pilot study.  Journal of American Podiatric Medical Association (2003) 63(1):18-22.
  9. Noncontact Radiant Heat Bandage for the Treatment of Wounds.  Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2009 July—Archived) Medicine: 2.01.41.

Noncontact Ultrasound Treatment for Wounds

  1. Ennis, W.J., Foremann,.P., et al.  Ultrasound therapy for recalcitrant diabetic foot ulcers: results of a randomized, double-blind, controlled, multicenter study.  Ostomy Wound Management (2005 August) 51(8):24-39.
  2. Alvarez O, Patel M, Rogers R et al. Effect of non-contact normothermic wound therapy on the healing of diabetic neuropathic foot ulcers. J Tissue Viability 2006; 16(1):8-11.
  3. MIST Therapy System.  Celelration, Incorporated.  Available at http://www.celleration.com (accessed 2012 February 29).
  4. Kavros, S.J., Miller, J.L., et al.  Treatment of ischemic wounds with noncontact, low-frequency ultrasound: the Mayo Clinic experience, 2004-2006.  Advanced Skin and Wound Care (2007 April) 20(4):221-6.
  5. Kavros SJ, Liedl DA, Boon AJ et al. Expedited wound healing with noncontact, low-frequency ultrasound therapy in chronic wounds: a retrospective analysis. Adv Skin Wound Care 2008; 21(9):416-23.
  6. Samies J, Gehling M. Acoustic pressure wound therapy for management of mixed partial- and full-thickness burns in a rural wound center. Ostomy Wound Manage 2008; 54(3):56-9.
  7. Ramundo J, Gray M. Is ultrasonic mist therapy effective for debriding chronic wounds? J Wound Ostomy Continence Nurs 2008; 35(6):579-83.
  8. Bell AL, Cavorsi J. Noncontact ultrasound therapy for adjunctive treatment of nonhealing wounds: retrospective analysis. Phys Ther 2008; 88(12):1517-24.
  9. Association for the Advancement of Wound Care (AAWC). Association for the Advancement of Wound Care guideline of pressure ulcer guidelines. Malvern, PA. Available online at: www.guideline.gov (accessed September 2011).
  10. Driver VR, Yao M, Miller CJ. Noncontact low-frequency ultrasound therapy in the treatment of chronic wounds: A meta-analysis. Wound Rep Reg 2011; 19(4):475-80.
  11. Non-Contact Ultrasound Treatment for Wounds.  Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2012 February) Medicine: 2.01.79.
History
December 2012  Policy updated with literature review through August 2012; references 5, 6 and 8 added; other references renumbered or removed; policy statement unchanged. 
September 2013 Policy formatting and language revised.  Policy statement unchanged.  Title changed from "Non-Contact Ultrasound Treatment for Wounds" to "Noncontact Wound Therapy".  Added codes A6000, E0231, and E0232.
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Noncontact Wound Therapy