Efficacy of the Application of a Purified Native Collagen With Embedded Antimicrobial Barrier Followed by a Placental Allograft on a Diverse Group of Nonhealing Wounds of Various Etiologies: A Case Series

George J. Koullias, MD, PhD

Disclosures

Wounds. 2021;33(1):20-27. 

In This Article

Discussion

In this case series, acute wounds such as traumatic (n = 4), postoperative (n = 5), and insect bite (n = 2) exhibited chronicity, with wound duration ranging from 1.25 months to 9 months (Table 1, Table 2). As also depicted in Table 1 and Table 2, a duration of 3 months to 5 months was noted for chronic wounds such as VLUs (n = 2), DFUs (n = 2), and pressure ulcer (n = 1). The formation of biofilm contributes to wound chronicity by prolonging the inflammatory phase as a result of elevated pro-inflammatory cytokine and protease levels.[4,19] Regardless of the varied etiology of nonhealing wounds, experts currently believe that nearly all chronic wounds contain biofilm and that preventing its recurrence may be the common denominator in successfully managing these wound types.[19,38,39] A reduction in biofilm levels may help halt unmanageable inflammation and may prompt the wound regenerative phases of proliferation and remodeling, which is clinically manifested by reduced inflammation, reduced drainage, decreased pain, and the appearance of granulation tissue.

Wounds can progress to closure after the transition is made from the inflammatory to the proliferative phase. However, wounds in which the process stalls in the proliferative phase could potentially benefit from pro-healing cytokines and growth factors. The author's clinical experience has shown that correcting for any coexisting arterial or/and venous insufficiency, reducing inflammation by managing biofilm, and then introducing a regenerative response in the wound bed are essential steps in accelerating wound healing. The approach and choice of product combination used in the algorithm reported here were selected based on the treatment hypothesis that after correcting for any coexisting arterial or/and venous insufficiency, PCMP in combination with aggressive debridements and optimal wound care practices, can potentially reduce biofilm re-formation and protease levels, which can in turn help transition the wound from an inflammatory phase to a reparative one. The addition of the application of placental allografts to the wounds would provide regenerative factors necessary for wound healing progression.

The results of this case series support this hypothesis. Most wounds (86.7%) achieved CWC by week 12, and the remaining 2 wounds (13.3%) closed by week 17. Complete wound closure, which in some cases was complicated by multiple comorbidities, was achieved in a varied group of wounds, such as VLUs, DFUs, pressure ulcers, postoperative wounds, and insect bites. The average size of the wounds was 20.16 cm2 (Table 1). The mean time to complete closure (9.33 weeks) was less than half the mean wound duration (22.32 weeks [5.58 months]). A subgroup analysis of the larger wounds (ie, VLUs, DFUs, postoperative) showed favorable (considering wound size and complexity) mean time to CWC of 11.6 weeks. Additionally, 60% of the wounds closed before 12 weeks.

A few important points must be made concerning the treatment strategy presented herein. First, it is important to emphasize the prompt, early, and diligent approach in improving all amenable metrics concerning the arterial, venous, and lymphatic conditions of the wounds. Although improvement of these metrics alone will not result in wound healing, the author strongly believes that such improvement can maximize the wound healing potential of advanced wound care products, thereby making this treatment algorithm more effective.

Second, all of the patients in this series underwent revascularization if occlusive disease was present in the artery responsible for supplying the wound or if the tissue pressure adjacent to an extremity wound was less than 60 mm Hg. Similarly, all patients with wounds associated with correctable forms of venous insufficiency that resulted in venous hypertension in the wound area (regardless of if the wound was a venous ulcer) were treated with open or endovenous intervention and/or microphlebectomy as well as sclerotherapy of the areas associated with the wounds. Coexisting lymphatic dysfunction was addressed with the use of inflatable extremity pumps.

From a clinical perspective, managing biofilm with proper debridements and prevention of biofilm re-formation by PCMP aids in the transition of a wound to the proliferative and remodeling stages of healing.[19] Nevertheless, some wounds at this stage may require regenerative factors (ie, growth factor, angiogenic factor) that may enhance wound healing. After biofilm has been managed using an application of PCMP, the application of dACM and HSAM can provide regenerative factors and benefit the reparative process.

Formulating a treatment strategy requires answers to pertinent questions specific to this strategy. At what point should the transition from the PCMP product to the amniotic products occur? What are the clinical indicators that signal depletion of the benefits PCMP to the wound? Should PCMP always be followed by a placental allograft or any other product to achieve wound closure? Can PCMP be used as a monotherapy for wound closure?

In this case series, PCMP was used up to the point at which infection was controlled; drainage, periwound erythema, pain level, and inflammation were reduced; wound size was decreasing; and granulation was present. Moreover, if wound size ceased improving in the absence of infection, a transition to using amniotic products was made. For several patients (not included in this series), the wound continued to improve with application of PCMP and healed completely without the need to transition to an amniotic product. The author believes that the presence of systemic causes (eg, rheumatic diseases) of microvascular disease or microvascular disease resulting from diabetes probably increases the likelihood of placental allograft product utility to achieve complete wound healing.

From a safety perspective, multimodal applications of PCMP and either dACM or HSAM appear to be well tolerated. No systemic or local adverse events were attributed to these applications.

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