Kerecis Omega-3 fish skin: wound therapy for chronic wounds in Zürich

A wound that has not healed for weeks or months. Dressing changes you have every reason to trust. Ointments that have been tried on many patients before. And still: the wound edge stays red, the wound bed looks tired, and the skin margin does not move inwards. If you or a relative know this situation, you belong to the estimated 1 to 2 per cent of the adult population who develop a chronic wound at some point in their lives. At Dein Team fürs Leben, this is exactly when we use a biological matrix that has changed wound therapy considerably in recent years: Kerecis Omega-3 fish skin.

In brief: what Kerecis Omega-3 fish skin is

:::answer-block{eyebrow="In brief"} Kerecis Omega-3 is an acellular wound matrix made from the skin of North Atlantic cod (Gadus morhua), approved by the US FDA since 2013. In a gentle process, all cellular components are removed so that only the three-dimensional scaffold of collagen, proteins and omega-3 fatty acids (EPA and DHA) remains. Placed on the prepared wound, this matrix serves as a biological scaffold into which the body's own fibroblasts and keratinocytes migrate and form new tissue. Clinical studies of chronic, treatment-resistant diabetic foot ulcers show a significantly higher proportion of completely closed wounds after twelve weeks compared with standard wound dressings [Lullove et al., Wounds 2021]. Because the source is a cold-water fish, there are no known mammal-specific pathogens that could be transmitted [Magnússon et al., Mil Med 2017]. :::

Why standard wound care sometimes reaches its limits

Most wounds heal with well-managed standard therapy. Diabetic foot ulcers, venous and arterial leg ulcers, pressure sores and poorly healing surgical wounds are a different story. They often remain stuck in the inflammatory phase for months. The wound bed is covered by a biofilm, the local supply of oxygen and nutrients is reduced, and the body's own repair cells do not receive the right signal to work towards wound closure.

In this situation, a passive dressing is no longer enough. What the wound needs is a biologically active scaffold that invites the repair cells in and breaks through the chronic inflammatory environment. Precisely this point sets Kerecis apart from a conventional wound dressing.

What Kerecis actually does

The effect rests on three interrelated properties described in preclinical and clinical studies:

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• Structural scaffold. The pore structure of fish skin resembles that of the human dermis. It provides a three-dimensional scaffold into which fibroblasts and keratinocytes can migrate [Rakers et al., Exp Dermatol 2010].
• Omega-3 modulates inflammation. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduce the activity of pro-inflammatory mediators and support an environment that favours healing [Schiefer et al., Adv Wound Care 2022].
• Promotion of vascularisation. The matrix is colonised by the body and gradually remodelled into living tissue. Animal and in vitro data show increased angiogenesis in the wound bed [Magnússon et al., Mil Med 2017].
• Excellent biocompatibility. Because no cellular components are present and the donor is a fish, there is no known risk of transmitting mammalian viruses [Baldursson et al., Int J Low Extrem Wounds 2015]. :::

When we use Kerecis: indications and the evidence

We typically turn to this matrix for wounds that show no relevant tendency to heal after four to six weeks of consistent standard therapy. In the published studies, the most common indications are:

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• Diabetic foot ulcer. In a multicentre, blinded randomised trial, 67 per cent of the wounds treated with Kerecis were completely closed after twelve weeks, compared with 32 per cent under a standard wound dressing (P = 0.0152) [Lullove et al., Wounds 2021].
• Venous and arterial leg ulcers. Retrospective case series show accelerated wound closure in previously treatment-resistant cases [Michael et al., Wounds 2019].
• Pressure sores. Particularly deep pressure ulcers with exposed fascia or tendon tissue.
• Poorly healing surgical wounds and wound dehiscence after vascular or orthopaedic surgery.
• Traumatic wounds and partial-thickness burns.:::

Important: Kerecis is no substitute for diagnostics. Anyone with a poorly healing wound on the leg first needs the blood supply assessed. Without adequate arterial perfusion, even the best matrix cannot heal. We keep to this order without exception.

How it works at Dein Team fürs Leben

As a rule, the path involves three stages:

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• Initial consultation and diagnostics. We take the wound history, assess the wound bed, wound edge and surrounding skin, and arrange the necessary investigations (ankle-brachial index, Doppler, imaging where required, metabolic laboratory tests).
• Wound bed preparation. Before the first Kerecis application, the wound is cleaned, devitalised tissue is removed and any infection is brought under control. This phase often decides more about the outcome than the product itself.
• Application and follow-up. The matrix is applied under sterile conditions and secured with a suitable secondary dressing. Depending on the wound, dressings are changed every seven to fourteen days. In most cases, two to six applications are needed before the wound becomes measurably smaller and new tissue appears. :::

These figures come from the published literature and match our practical experience. They are not a promise. Wound healing is always individual and depends on blood vessels, metabolism, nutrition and mobility. We look after precisely these factors in parallel, because they help decide whether healing succeeds.

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Is Kerecis treatment covered by health insurance?

Cover is decided case by case. Given a clearly justified medical indication, documented resistance to treatment and a corresponding prescription, the application is in many cases covered by compulsory basic insurance (Grundversicherung). We clarify the cost situation with you and your health insurer before the first application.

Is the application painful?

Placing the matrix itself is not painful. Wound bed preparation, meaning the cleaning and removal of devitalised tissue, can be done under local anaesthetic depending on the depth of the wound. Many patients report a noticeable reduction in wound pain after the first application, presumably because the matrix covers the exposed nerve endings.

How does Kerecis differ from a skin graft?

In a conventional skin graft, your own skin tissue is taken from another site and transferred to the wound. Kerecis, by contrast, is not the body's own tissue. It is a biological matrix that serves as a scaffold. The body colonises it and remodels it into its own tissue. This avoids the need for a donor site.

Are there patients for whom Kerecis should not be used?

Yes. With a proven allergy to fish products, the application should be weighed carefully, even though no relevant immunological reaction to the acellular matrix has been described. In untreated critical ischaemia, restoring the blood supply comes before any matrix application. With an active deep wound infection, the infection is controlled first.

How quickly will we see whether the therapy is working?

We typically expect the first objective signs (a reduction in wound area of at least fifty per cent against the baseline findings) within four to six weeks. If this reduction does not occur, we reassess the strategy rather than sticking with the procedure. :::

Prof. Dr. Craig K. Fritz M.Sc., Physician Associate for General Internal Medicine, Pain Medicine, Practice Lead Dein Team fürs Leben.