Comparing Calcium Alginate Dressings to Vacuum-assisted Closure: A Clinical Trial

Introduction. Several treatment modalities and protocols for arterial wound ulcers are available; however, little consensus exists on which treatment modality provides the best results. The present study sought to compare and evaluate the clinical efficacy of vacuum-assisted closure wound therapy to calcium alginate dressings in the treatment of neuroischemic diabetic foot ulceration. Material and Methods. A single-center quasi-experimental matched subject clinical trial was conducted on 30 subjects living with type 2 diabetes and presenting with a newly diagnosed neuroischemic foot ulceration. Subjects were divided into 2 groups. Group A (n = 15) underwent negative pressure wound therapy and Group B (n =15) underwent treatment using calcium alginate dressings. Ulcer area and depth were measured during the trial. Results. Both negative pressure therapy and calcium alginate dressings were effective in reducing the surface area and depth of ulcers (P = 0.0001). However, negative pressure was 3.2 times more effective in reducing surface area and 3.78 times more effective in reducing depth of ulcers when compared to calcium alginate (P = 0.0001). Conclusion. Vacuum-assisted closure should be considered as the treatment of choice for neuroischemic ulceration owing to its advantages in reducing surface area and depth when compared to calcium alginate dressings. Improved care could result in improved health outcomes, improved quality of life, and fewer diabetes-related foot complications.

The incidence of diabetes is increasing worldwide and an estimated 4%-10% of people with type 2 diabetes develop foot ulcerations.¹ This is of concern for both people with diabetes and health care providers, with episodes of ulceration strongly associated with lower-extremity amputations, reduced quality of life, long periods of hospitalization, and substantial health care costs.²

Diabetic foot ulcerations can take weeks or months to heal, and sometimes do not heal at all.³ Owing to poor healing results, many patients will need to be admitted to the hospital for inpatient treatment.⁴ Nonhealing ulcerations can result in local infection, gangrene, and amputation of the limb.⁵ This emphasizes the importance of ensuring continuous research to identify the best methods of management to ensure high quality and effective treatment.⁶

A vast range of treatment modalities and protocols are available for the treatment of diabetic arterial foot ulcerations ranging from conventional wound dressings to more sophisticated procedures such as hyperbaric oxygen, maggot therapy, and vacuum-assisted closure therapy.⁶ However, apart from the fact that ulcers should be debrided of necrotic and fibrous tissue to allow formation of granulation tissue, adequate epithelialization, and decreased chance of infection,⁷ little consensus exists on which dressing, antiseptic agent, or therapy would be ideal to treat these ulcers. This lack of evidence is due to the lack of research-based evidence to sustain the use of one particular treatment over another.⁸ Bearing in mind that wound repair and management is a highly complex combination of matrix destruction and reorganization,⁶ it is of utmost importance that research about the different wound products and treatment modalities currently available on the market is ongoing. No single wound product can be described as optimal or ideal for all types of ulcerations since the choice of dressing is dependent on a plethora of wound factors including the amount and type of drainage, size, depth, and type of ulceration, as well as the appearance of the surrounding skin.⁹ A Cochrane review¹⁰ suggested that not enough evidence is available when comparing negative pressure wound therapy to other treatment modalities and more studies need to be conducted. This paucity of information prompted the authors to conduct this study.

The main purpose of this research was to compare and evaluate the effectiveness of 2 treatment modalities for neuroischemic diabetic foot ulceration: vacuum-assisted closure wound therapy vs calcium alginate dressings. This study is novel in nature since, following a vast literature search, no studies were found which sought to compare the 2 treatment modalities described below.

Calcium alginate dressings are used in moderately to heavily exudating and bleeding wounds. They consist of a water-insoluble, gelatinous, cream-colored substance¹¹ created by the addition of aqueous calcium chloride to aqueous sodium alginate. Alginate is a substance present in cell walls of brown algae, as the calcium, magnesium, and sodium salts of algaeing acid.¹² This dressing is nonocclusive, nonadhesive, and moisture-retentive and can be applied to partial-thickness or full-thickness wounds once or twice daily.

This dressing is available in 3 different forms: ropes, ribbons, and sheets.¹³ The soft, white sterile dressings of calcium alginate absorb moderate to large amounts of wound drainage and help in controlling minor bleeding. The dressing forms a sac-like pocket that is moist over the wound while the surrounding skin remains dry. The rope structure of the dressing can be used to fill and pack the dead space in a wound to absorb exudate even if heavy drainage is present. The alginate turns into a viscous hydrogel when exudate is absorbed. Calcium alginate dressings have the ability to form gel with fluid absorption through capillary actions where the fibers swell when debris and bacteria are collected. Also, the dressing is permeable to gas and has a hemostatic effect but does not have any bactericidal effect even though it eliminates germs by physical action.¹⁴

A study carried out by Jones et al¹⁵ suggests that calcium alginate dressings can absorb up to 15%-20% of their weight in exudate fluid. Another important advantage of the dressing is that it does not have to be changed daily and thus makes it easier for the patient to continue therapy even when at home. Kumar¹⁶ suggests that a major drawback in the use of such dressings is that they are ineffective in reducing the bacterial load in an infected wound.

Through the application of negative pressure mechanical forces, negative pressure wound therapy (NPWT) is used to manage wounds and to create an environment that promotes healing. These forces are known as macrostrain and microstrain into cellular response.¹⁷ Macrostrain is defined as the visible stretch that occurs when negative pressure contracts the foam which reduces the wound size by drawing the wound edges together, provides direct and complete wound bed contact, evenly distributes negative pressure, and removes exudate and infectious material. The generation of macrostrain is dependent upon the mechanical properties of the dressing. Microstrain is the microdeformation at the cellular level, which leads the cell to stretch by reducing edema, promoting perfusion, and promoting granulation tissue formation by facilitating cell migration and proliferation.¹⁸ The generation of microstrain at the wound is dependent upon the ability of the tissue interface to transfer pressure to the tissue. Studies have shown that mechanical forces in the wound bed mediate the appearance of functional vasculature¹⁹ and have also been associated with angiogenesis.²⁰ Since pressure transferred to the wound results in cellular responses, it is highly recommended that the pressure delivered be consistent and controlled throughout the entire wound bed.²¹

Negative pressure wound therapy works by a mechanism that includes fluid removal, drawing the wound together, microdeformation, and moist wound healing.²² Its application provides a quick wound bed preparation. It is understood that the acceleration in wound healing comes about from the alteration of the microvascular blood flow in the wound edge. 

The therapy involves a controlled application of subatmospheric pressure at the wound using a sealed wound dressing connected to a vacuum pump.²³ Fluid is drawn out from the wound by the continuous vacuum and blood flow is increased at the area promoting faster wound healing.²⁴ The vacuum is applied continuously or intermittently depending on the type of wound treated and the clinical objectives of the practitioner, and the dressing is changed 2-3 times a week. Standard negative pressure used is -125 mm HG; however, other studies²⁵ have suggested different values, since at -125 mm Hg some patients experience pain and ischemia. Therefore, the pressure should be reduced according to the wound type and tissue composition. Birke-Sorensen and coauthors²⁶ suggest that the dressing used for the technique includes an open-cell foam dressing and gauze sealed with an occlusive dressing to keep the vacuum at the wound site.

The technique used in applying negative wound pressure includes a dressing or filler material which is fitted to the contours of the wound and then covered with a nonadherent dressing film. Three types of fillers are normally used: foams which are cut to fill open cavity wounds; open-weave cotton gauze; or layers of nonwoven polyester joined by a silicone elastomeric.²⁷ The filler is then sealed with a transparent film. A drainage tube is fixed to the dressing through an opening in the transparent film which runs to a canister on the side of the vacuum pump. This results in a closed wound in which circulation is increased and all excess fluids are removed,²⁴ creating a moist healing environment and reducing edema.

Once the dressing is completely sealed at both ends, the vacuum pump is set to either produce a continuous or intermittent pressure that varies between -125 mm Hg and -75 mm Hg, depending on material used and the patient’s tolerance.²⁷

Studies advocate for further research of the use of NPWT in different type of wounds and related complications to better understand the use of this technology.²⁸ Notwithstanding the positive results that have confirmed the therapy as safe,²⁸ serious complications including bleeding and infection have recently been reported in small groups of patients.²²

A single-center, quasi-experimental matched subject clinical trial was conducted on 30 subjects living with type 2 diabetes and presenting at the Tissue Viability Unit in the outpatient clinic at Mater Dei Hospital, Msida, Malta, with a newly diagnosed neuroischemic foot ulceration. Quasi-experimental designs are identical to experimental designs but lack random assignment to treatment and control and can thus allow the researcher to control assignment to treatment conditions using criteria other than random assignment. This study was approved by the University Research Ethics Committee and all participants were provided with trial information sheets. Written informed consent was obtained before any data collection. All investigations were carried out in accordance with the principles of the Declaration of Helsinki as revised in 2000.

Subjects were eligible for entry in the study if they were living with type 2 diabetes, over 18 years of age, and newly diagnosed with a noninfected neuroischemic foot ulcer. Subjects were excluded if the patient’s foot wounds were purely arterial or neuropathic in nature; if the ulcer was infected; if, upon vascular examination, the wound was found to require immediate endovascular interventions or open surgical procedures; if the patient had to have their medications changed during the study period; or if the patient had a history of chronic alcohol abuse, systemic disease, or pernicious anemia.

The testing modalities and examination methods were carried out by the same investigator to ensure uniformity. Subjects were divided into 2 groups. Group A (n = 15) underwent NPWT with vacuum-assisted closure therapy and Group B (n = 15) underwent treatment using calcium alginate dressings. Both males (n = 20) and females (n = 10) were included. Participants were matched for age, gender, duration of diabetes, current medications, HbA1c levels, size of wound, and the site of wound (according to the angiosomes supplying the wound area with arterial blood) using frequency distribution matching to ensure both groups were comparable at baseline. Initial surface area and initial depth of ulcers varied marginally between both groups at the start of the study as illustrated in Tables 1 and 2. In this study, 15 patients were excluded during the study due to infection (n = 6), need for amputation (n = 3), or need for changing dressing type to another type (n = 6), leaving a total of 30 participants to be included in the clinical trial.

The examination process involved review of the patient’s medical history and a lower-extremity physical examination. Each individual’s personal lifestyle characteristics and clinical history including duration of diabetes, last HbA1c reading, blood pressure, dyslipidemia, diabetic retinopathy, nephropathy, neuropathy, weight, height, current medications, smoking and drinking history, and history of any past ulceration were recorded. Using previously published methods,^29,30 the researcher carried out a neurological and vascular assessment to determine the neurological and vascular status of the lower limb.

Ulcer characeristics. The testing modalities and examination methods were carried out by the same investigator to ensure uniformity. Testing was performed at the outpatient clinic. Room temperature was kept at 21°C to 23°C (68°F to 75°F) during the assessments to avoid vasoconstriction of digital arteries from the cold. The screening process involved review of the patient’s medical history and a lower-extremity physical examination. Individual assessments took approximately 45 minutes.

Peripheral sensory neuropathy. Semmes-Weinstein 5.07 monofilaments, exerting 10 g of force, were used to identify peripheral sensory neuropathy.²⁹ The 5-point test was used. The plantar aspect of the hallux and third digit together with the first, third, and fifth metatarsal heads were used for testing. With the eyes closed, the patient related to the investigator when he or she could feel the monofilament.

Peripheral arterial disease. The vascular status was assessed using the 6 P’s guideline where the foot was tested for pulselessness, pallor, pain, paresthesia, paralysis, and perishing cold.³¹ The skin was assessed for any changes in color and temperature gradient was noted. Subpapillary plexus filling time was also noted. Peripheral arterial disease (PAD) was assessed using the documentation of history of intermittent claudication, rest pain, and palpation of peripheral pulses. An experienced clinician conducted the palpation of pulses using fingertips. Dorsalis pedis and posterior tibial pulses were recorded. Cyanosis, cold feet, skin thinning, and hair anomalies were also recorded. Claudication was evaluated from information supplied by the patient with regard to exercise-induced calf, thigh, and/or buttock pain. Measurement of ankle brachial pressure index (ABPI) was performed using a portable handheld Doppler and blood pressure cuffs. In addition to the ABPI assessment, quantitative pedal waveform analysis was obtained from all recruited subjects utilizing the continuous wave Doppler. The Doppler waveforms and the measurement of the ABPI were obtained using the Dopplex Assist Vascular Package (Huntleigh, Cardiff, UK) as the principal study tool.

A handheld continuous wave Doppler with an 8MHz probe was used to measure the waveforms of the dorsalis pedis and the posterior tibial. The probe was held steadily on the anatomical artery location at an angle between 45-60 degrees against the flow of arterial blood. Interpretation of arterial pressure waveform results was based on standards from the literature.³² Waveforms were classified as triphasic, biphasic, monophasic discontinuous, and monophasic continuous. The triphasic waveforms were considered as normal, whereas the biphasic, monophasic discontinuous, and monophasic continuous waveforms were interpreted as abnormal.

Measurements were carried out after patients rested for 5 minutes in the supine position with the upper body as flat as possible, since measurements in the sitting or semi-sitting position can result in a substantial blood increase in the tibial arteries. Patients were also asked to undo all tight clothing around the waist and arms.  Handheld portable assessment systems (Dopplex Assist Series, Huntleigh, Cardiff, UK) were used to measure resting ABPI. According to the company specifications, ABPI measurement is one of the instrument’s principal applications apart from waveform analysis. The series used for this study included an electric pump that deflates the pressure cuffs, requiring the investigator to simply press a button. An optimum Doppler signal is achieved at an angle of 45-60 degrees. When measured, the systolic blood pressures are automatically saved onto the system’s software with the saved results then used to calculate the ABPI ratios by the system.

A blood pressure cuff was applied to the arm to measure the brachial systolic pressure and to the ankle to measure the dorsalis pedis and posterior tibial pressures to determine the ankle pressure. The cuff was inflated to occlude the arterial pressure. A researcher obtained the systolic pressure by listening and noting the pressure on the manometer.The systolic pressure was noted and the higher values of the brachial and the ankle pressures were used to calculate the ABPI. Values were interpreted according to the criteria proposed by the American Heart Association and the American Diabetes Association.³³ In this research, ABPI calculations were interpreted as normal when within 0.9-1.29; lower-extremity vascular disease was defined an ABPI < 0.90 in either foot; and an ABPI > 1.3 was considered significantly elevated and indicative of vascular calcification.

Ulcers were categorized according to their type. Neuroischemic ulcers were included in this study. Patients with an ABPI < 0.9 mm Hg and whose peripheral sensation was poor were diagnosed as having a neuroischemic ulcer. The typical characteristics of a neuroischemic ulcer were a base of sparse pale granulation tissue, and a yellowish, closely adherent slough usually found on the margins of the foot, especially on the medial surface of the first metatarsophalangeal joint and over the lateral aspect of the fifth metatarsophalangeal joint.

Procedure for wound measurement. For the purpose of this study, acetate tracing paper with a printed grid was used to calculate the area of the wound and sterile probes were used to calculate the depth of the wound. A fine-tipped permanent marker was used to trace the wound outline. Minimal pressure was applied whilst tracing to prevent distorting the shape and border of the ulceration. A 0.2 cm² grid was used to calculate the area of the ulcer to increase precision. Acetates offer a good indicator of wound size as confirmed by various studies which have compared this method to various other devices such as planimetry.³⁴ When recording the depth of the ulcer, the deepest part was identified and the probe used had a millimeter scale to ensure precision. The PEDIS (perfusion, extent/size, depth/tissue loss, infection, sensation) grading system was used to grade the ulcerations.³⁵ In this study, ulcerations included were recorded as a grade 2 or 3 on the PEDIS grading system.

Treatment procedure. Using convenience sampling, the first patient recruited was assigned to Group A (NPWT) and when a suitable match was found, the matching patient was assigned to Group B (calcium alginate dressing). This was repeated until a total of 15 subjects were recruited in each group. Participants had to visit the hospital’s outpatient clinic every 3 days for a change of dressing by a tissue viability nurse. Participants were reviewed clinically by the same independent researcher. During each visit, the wound was cleansed with sterile saline solution and any superficial dead tissue or callus was debrided using a sterile scalpel. The wound was cleansed again with saline solution and measured as described above. Following the measurements the treatment was reapplied.

Negative pressure wound therapy was ended when uniform granulation tissue was obtained as suggested in the literature.²⁶ Participants who, during the course of the study, presented with infection to the wound requiring antibiotics or who needed a change in the type of dressing were excluded since they no longer fulfilled the study protocol. Appropriate treatment and psychological support was provided when deemed necessary.

Negative pressure wound therapy. Vacuum-assisted wound therapy (V.A.C., KCI, Houten, Netherlands) is a noninvasive system that creates a localized controlled subatmospheric negative pressure environment. Vacuum-assisted therapy promotes wound healing by delayed primary or secondary intention by creating a moist wound environment, preparing the wound bed for closure, reducing edema, and promoting formation and perfusion of granulation tissue. This type of therapy is indicated for use in all care settings and for a variety of wound types including diabetic foot ulcers. The vacuum-assisted therapy used for this study consisted of polyurethane foam dressing with a pore size of 400-600 um and a continuous negative pressure of 125 mm Hg. The foam was appropriately trimmed to fit each wound. A noncollapsible drainage tube embedded in the foam was connected to the vacuum-assisted pump; an airtight adhesive drape was applied on top of the foam. Foam dressings were changed every 72 hours. Participants using this therapy did not change their dressings at home. All wounds were inspected after 72 hours. This treatment was applied to the ulcer as specified by manufacturer’s guidelines,³⁶ and treatment was continued until ulcer closure.

Calcium alginate dressing. The calcium alginate dressings (Algisite M, Smith and Nephew, St. Petersburg, FL) consisted of a water-insoluble, gelatinous, cream-colored substance created by the addition of aqueous calcium chloride to aqueous sodium alginate. This dressing is nonocclusive, nonadhesive, and moisture-retentive. For the purposes of this study, it was applied to the wounds once daily. A secondary dressing was used to secure the alginate dressing in place. Dressings were changed daily by a state-registered community tissue viability nurse assigned to the patient.

During both therapies, all participants were encouraged to remain as active as possible. The primary efficacy endpoint was incidence of complete ulcer closure. Secondary end points included a reduction in ulcer surface area over time.

A total of 30 participants living with type 2 diabetes and presenting with a neuroischemic foot ulcer were included in this study. A total of 20 males and 10 females were included. Mean age for Group A (NPWT) was 59.9 years and mean age for Group B (calcium alginate) was 63.3 years. The mean duration of diabetes for Group A was 3.9 years and the mean duration for diabetes for Group B was 4.4 years. Twenty-two participants were on oral glycemic medication and 8 participants were on insulin therapy. The mean HbA1c for Group A was 9.7 while the mean HbA1c for Group B was 8.5. Table 3 provides ulcer surface area and depth of each participant at the start of the study and end of clinical trial.

Initial surface area and initial depth between were compared between groups using the independent sample  t test to ensure that ulcerations were precisely matched at the start of the study. There was no difference in initial surface area (P = 0.461) and initial depth (P = 0.569) between groups at the start of the study.

However, when the mean surface area and mean depth were analyzed and compared at the end of this study, negative pressure was found to be 3.2 times more effective in reducing surface area and 3.78 times more effective in reducing depth of ulcers when compared to calcium alginate (mean change surface area: negative pressure, 3.57cm²; calcium alginate, 1.09cm²; P = 0.0001) (mean change depth: negative pressure, 0.68 cm; calcium alginate, 0.18cm; P = 0.0001).

Further statistical analysis was conducted to compare the mean surface area and mean depth before and after each individual treatment. The paired sample t test was used to analyze this data. Results conclude that both NPWT (initial mean surface area, 11.49 cm²; final mean surface area, 7.92 cm²; P = 0.0001; initial mean depth, 1.59 cm, final mean depth, 0.90 cm; P = 0.0001) and calcium alginate dressings (initial mean surface area, 10.50 cm²; final mean surface area, 9.41cm²; P = 0.0001; initial depth, 1.52 cm; final depth, 1.34 cm; P = 0.0001) were effective in reducing the surface area of arterial ulcerations in the study group.

Dressings form a key part of ulcer treatment, with clinicians and patients having many different types to choose from.³⁷ Clear evidence is required to facilitate decision-making regarding the use of an appropriate dressing. Despite the developments in the various treatments and protocols for ulceration, many wounds do not heal satisfactorily in an outpatient clinic within the timeframe the care provider would expect that specific wound to heal (depending on the nature of the presenting wound). Diabetic foot complications and ulcerations remain a global concern since they can be a precursor to lower extremity amputations, lower the quality of life of individuals living with diabetes, and account for a large proportion of hospitalizations and a substantial amount of incurred hospital costs.³⁸ In this study the authors sought to compare and evaluate the effectiveness of vacuum-assisted closure treatment in neuroischemic ulcerations with a current standard calcium alginate wound dressing. This study shows vacuum-assisted closure therapy results in a significant reduction in wound surface area and depth when compared with calcium alginate dressings, providing patients adhere strictly to the treatment protocol and trained health care professionals administer this treatment appropriately. Although the HbA1C was higher for the NPWT group when compared to the calcium alginate group, this group still demonstrated improved healing. It has been hypothesized that HbA1c is a biomarker in predicting wound healing rate in patients with diabetes and that elevated HbA1c levels are mostly associated with poor wound healing. Given the large burden of arterial diabetic ulcerations, it is important to identify prognostic factors that could aid healing and help optimize wound care.³⁹

Negative pressure wound therapy using vacuum-assisted closure has been used in the management of wounds and its use has increased dramatically over the 1990s and 2000s⁴⁰; however, to date, it is not yet widely used in an outpatient setting.⁴¹ The original impetus for developing vacuum-assisted closure was for the treatment of chronic and difficult-to-treat ulcerations in inpatient hospital settings.⁴² However, results from this study have shown that participants presenting with neuroischemic ulcerations and treated with vacuum-assisted closure in an outpatient hospital setting reported improved healing rates when compared to participants treated with calcium alginate dressings.

Although one of the limitations of this study could be the sample size (n = 30) since, ideally, larger cohorts increase statistical power, the results of this study are congruent with a similar study which sought to compare conventional dressing methods to vacuum-assisted closure wound therapy.⁴³ The authors concluded that negative pressure had a faster rate of wound healing and granulation tissue formation (P = 0.002). However other studies have failed to conclude whether negative pressure is better than any other treatment modalities.^10,44 It could be argued that another limitation of this study was the fact that arterial disease was diagnosed using ABPI measurements and spectral waveforms. Ankle brachial pressure index measurements are notoriously unreliable with patients who have diabetes when there is concomitant high risk of arterial calcification, where the reliability of ABPIs seems to be limited since a falsely elevated reading can be produced. Still, ABPIs were used since they are a standard assessment tool in the clinic where the study was conducted. Equipment is not readily available at the location for measuring toe brachial pressure and transcutaneous oxygen, and so is noted as a limitation of the study. Absolute toe pressure measurements are usually recommended in these cases were ankle arteries are incompressible because toe systolic blood pressures are not usually affected by calcification and false positive results are reported to be rare. Transcutaneous oxygen pressure or skin perfusion pressure could also have been included to identify microvascular disease in the recruited subjects.

The conflicting results regarding outcomes on various treatments in neuroischemic wound management stimulate discussion concerning what is crucial to improving diabetic wound management. The ethical and financial aspects when choosing an appropriate dressing for patients need to be taken into consideration. The advantages and disadvantages of different treatment modalities need also be considered by health care professionals and discussed with the patients prior to choosing a specific treatment modality for patients. Vacuum therapy provides advantages over conventional dressings. One of the important advantages of vacuum-assisted closure therapy is that chemical debriders and antimicrobial solvents, which are suspected cytotoxic agents, are not indicated in this treatment modality.⁴⁵ Furthermore, another major advantage in vacuum therapy is the reduction in the number of dressing changes required when compared to conventional therapy,⁴² resulting in better patient compliance and less inconvenience. Vacuum-assisted therapy has also been reported to be more cost-effective for health care providers, since it requires fewer dressing changes and reduced nursing care; and more cost-effective for patients, especially when patients need to absorb the cost of conventional therapy (eg, wound care dressing other than vacuum-assisted closure therapy) themselves, which can be quite costly.⁴⁶ With these reasons in mind, vacuum-assisted closure therapy should be considered as an alternative treatment in the management of acute diabetic arterial ulcerations. Healing using vacuum-assisted closure occurs by a number of mechanisms including stimulation of blood flow, removal of bacteria, and regeneration of the wound environment. Healing ulcers more quickly with negative pressure translates into less treatment time with the potential for early discharge, a reduction in the number of district nurse visits, and a reduction in the use of other expensive dressings, thus reducing the financial burden from both patients and the health care system.

Further prospective studies with the inclusion of a larger population sample should be conducted for generalizability of study results.

Negative pressure wound therapy using vacuum-assisted closure appears to be safe and more effective than calcium alginate dressings for the treatment of neuroischemic ulcerations. This prospective clinical trial has demonstrated that vacuum-assisted closure therapy was 3.2 times more effective in reducing the surface area of diabetic arterial ulceration, and 3.78 times more effective in reducing ulcer depth when compared to calcium alginate dressings in an outpatient clinical setting. These findings have important implications for clinical practice, especially in an outpatient setting. Improved care could result in improved health outcomes, improved quality of life, and lesser diabetes-related foot complications.

The authors would like to thank all participants who consented to participate in this study.

Affiliations: Department of Health, Valletta, Malta; and Faculty of Health Sciences, University of Malta, Msida, Malta

Correspondence:
Cynthia Formosa, PhD, SR Pod, MPodA
Faculty of Health Sciences
University of Malta
Tal-Qroqq
Msida, Malta
Cynthia.formosa@um.edu.mt

Disclosure: The authors disclose no financial or other conflicts of interest.