The Use of Kerecis Omega3 Wound Fish Skin Graft for the Treatment of Deep Burn Wounds

Abstract

Background:

Addressing deep partial-thickness burns (DPTBs) and full-thickness burns (FTBs) remains a significantly challenging task in modern burn surgery. Among a broad lineup of wound products, biological adjuncts like fish skin–derived scaffolds offer unique regenerative properties, presenting new possibilities in complex wound management. We herein report our institutional clinical experience with the fish skin–based scaffold Kerecis Omega3 Wound.

Methods:

This retrospective, single-center case series evaluated all patients with DPTBs and FTBs treated with Kerecis Omega3 Wound between 2020 and 2024 at the burn center of the University Hospital Zurich. The specific indications for intervention, depth of burn injury, anatomical regions of application, subsequent need for further surgery, and short- and long-term complications were systematically assessed.

Results:

Twenty-seven patients were reviewed, exhibiting a mean affected total body surface area of 35.73% and an average abbreviated burn severity index score of 7.74. Fish skin was used in an acute setting in 21 cases; for the remaining cases, it was used for chronic wound-healing disturbances following burn injury. The most frequently treated anatomical region was the upper extremity. Almost 50% of the DPTB wounds healed spontaneously following treatment with Kerecis Omega3 Wound. Conversely, all FTBs required further skin grafting or other reconstructive measures. Postsurgical infections occurred in 4 patients, necessitating the removal of the product. Contractures were observed in 3 patients with FTBs during clinical follow-up.

Conclusions:

Kerecis Omega3 Wound represents a valuable adjunct for wound conditioning in patients with DPTBs, either as a preparation before skin grafting or to stimulate spontaneous wound regeneration. Regarding FTBs, its efficacy in restoring the dermal layer requires further research and clinical validation.

Takeaways

Question: Can the fish skin scaffold Kerecis Omega3 Wound support wound conditioning and healing in patients with deep-partial and full-thickness burns?

Findings: In this retrospective single-center case series of 27 patients with severe burns, Kerecis Omega3 Wound facilitated spontaneous healing in nearly 50% of deep-partial thickness burns, often avoiding further surgery, but all full-thickness burns still required grafting or reconstruction.

Meaning: Kerecis Omega3 Wound shows promise as an adjunct for burn wound management, especially in deep-partial burns, but further research is needed for full-thickness injuries.

INTRODUCTION

Despite continuous advances in the field of burn patient care, the surgical management of deep partial-thickness burns (DPTBs) and full-thickness burns (FTBs) remains challenging due to a lack of donor sites, as well as frequent complications such as infections and sepsis, especially in the context of a rising incidence of multidrug-resistant organisms.^1,2 In addition, long-term outcomes and quality of life play an increasingly important role for affected patients due to increasing survival rates of severely burned patients. To mitigate these challenges and improve overall outcomes, the search for wound care adjuncts continues. Biological scaffolds were developed to provide a readily available off-the-shelf dermal regeneration method for surgeons. Integra Dermal Regeneration Template (Integra LifeSciences, Princeton, NJ), for instance, is composed of a sheet of a porous, cross-linked type I collagen and glycosaminoglycans, covered by a semipermeable silicone layer, and is meant to guide wound healing and tissue regeneration. It was initially developed for the postexcisional treatment of patients with DPTBs with limited autograft donor sites.³ Over the years, its use has expanded and is nowadays used for a variety of reconstructive indications. Contrary to this development, the Kerecis Omega3 Wound fish skin graft (Kerecis, Ísafjörður, Iceland) was initially used in the treatment of chronic foot ulcers and has gained popularity in recent years for its promising results in accelerating wound healing.⁴ Due to these favorable experiences, the use of Kerecis Omega3 Wound has also spilled over into the field of burn care.^5–7 As it does not have to undergo viral inactivation like comparable mammalian-derived products, its structure and soluble components, such as omega-3 fatty acids, including docosahexaenoic acid and eicosapentaenoic acid, are preserved to benefit the wound-healing process and boost tissue regeneration.⁸ Other reported favorable effects of Kerecis Omega3 Wound include pain relief and the need for fewer dressing changes.^5,7,9 Compared with other scaffolds, Kerecis Omega3 Wound seems to have an inherent structural similarity to human skin, showing a low immunogenicity and high biocompatibility.¹⁰ Due to minimal processing, a high content of omega-3 fatty acids is preserved, allowing for anti-inflammatory,⁸ antimicrobial, and hypoallergenic effects.^11,12 By now, the indications for Kerecis Omega3 Wound vary widely and include acute and chronic wounds of various etiologies. It has also been suggested for battlefield wounds from thermal injuries due to its better applicability in combat zones compared with amniotic membrane.^13,14 In this particular context, the relatively high price of the product may be outweighed by the low weight and long shelf life. These aspects may, however, be less relevant in a hospital setting. With the present study, we aim to further explore the use of Kerecis Omega3 Wound in the context of burn injuries, as the precise indications are not yet fully defined due to sparse clinical experience and data. We herein report our experiences with Kerecis Omega3 Wound and its possible role in the wound management of severely burned patients with DPTBs and FTBs.

METHODS

Patient Characteristics and Clinical Application of Kerecis Omega3 Wound

In this retrospective case series, we report on all patients with DPTBs and FTBs treated with Kerecis Omega3 Wound from 2020 to 2024 at the burn center of the University Hospital of Zurich, Switzerland, with an approximate annual admission rate of 150–200 patients per year. All patients treated with Kerecis Omega3 Wound application at our unit were included in the present study. Inclusion criteria were patients aged 18 years or older who sustained DPTBs, mixed pattern burns, or FTBs and received treatment with Kerecis Omega3 Wound; exclusion criteria were superficial partial-thickness burns without indication for surgical intervention. Data on demographic characteristics, total body surface area (TBSA), depth and type of burn wound areas, abbreviated burn severity index (ABSI) score, body surface area (BSA) treated with Kerecis Omega3 Wound, and the ratio of BSA treated with Kerecis Omega3 Wound to the affected TBSA were collected and subsequently evaluated by an experienced board-certified plastic surgeon. Each area treated with the product, as differentiated by the depth of the defect, was evaluated as such. The decision to apply the product was made on a case-by-case basis by a senior surgeon, taking individual wound characteristics and clinical judgment into account. Therefore, the number of burn injuries does not correspond with the number of included patients. Moreover, the method of initial debridement (surgical or enzymatic), time until application, the need for further surgery, and time until secondary interventions were assessed. Furthermore, short-term and long-term complications were determined, specifically local wound infections, objectified by positive bacterial swabs. Scar quality was assessed by clinical examination with regard to pigmentation, itching, and development of contractures. In acute burn injuries and in burn wounds with chronic wound-healing disturbances, Kerecis Omega3 Wound served as a wound-conditioning tool to boost granulation for secondary healing or to optimize the wound bed for further skin grafting as a means of replacing lost dermis. Therefore, Kerecis Omega3 Wound was applied in 2 different settings: acute burn injury and chronic wound-healing disturbances after burn trauma.

In the first scenario, patients received their initial hydrotherapy and debridement upon admission to our Burns Center. Wound depth was clinically determined by senior burn surgeons at admission and 24 hours after trauma. Kerecis Omega3 Wound was manually meshed in a 1:3 ratio and applied early after debridement. Methods of debridement varied depending on the pattern of burn injury. Bromelain-based enzymatic debridement (NexoBrid, MediWound, Israel), traditional surgical excision, hydrosurgical excision (Versajet, Smith & Nephew, Hamburg, Germany), or combinations thereof were performed. Standard wound dressing consisted of paraffin gauzes with 0.5% chlorhexidine acetate (Bactigras, Smith & Nephew, Hamburg, Germany) and dry gauzes. The first dressing change was performed on the fifth postoperative day, and subsequent treatments were determined based on individual healing progress. The product was applied once and is intended to incorporate into the wound bed; no routine removal, replacement, or reapplication was performed. Chronic wound-healing disturbances after burn trauma, on the other hand, were defined as defects with inadequate healing tendencies more than 30 days after initial trauma. The product was applied directly after surgical wound debridement. Any further surgical interventions were decided depending on the individual case, taking the patient’s clinical condition and severity of the burns into account. Depending on the extent and anatomical localization of the defect, secondary interventions such as split-thickness skin grafts or flap coverage were performed. Spontaneous wound healing was defined as the primary endpoint, whereas healing time, rate of infection, need for additional surgery, and scar quality were defined as secondary endpoints.

Ethical Approval

The local ethics committee accepted this study (KEK-ZH-BASEC no.: 2024-01978).

RESULTS

Demographics, Trauma Characteristics, and Application of Kerecis Omega3 Wound

Twenty-seven patients were included, 8 of whom were women and 19 men, with a mean (median) age of 51 years (range 17–90 y). The most common causes of burns were flame and scald injuries (Fig. 1). The mean affected TBSA was 35.73%, and the average ABSI score was 7.74. Patients had on average 2.1 preexisting comorbidities at admission, predominantly arterial hypertension and diabetes. The distribution of the burn depth is shown in Figure 2: mainly, wound areas with DPTBs and FTBs were treated with Kerecis Omega3 Wound. Enzymatic debridement was performed in 48% of all cases; otherwise, surgical excision was carried out. The mean BSA covered with Kerecis Omega3 Wound was 5.3%, and the relative proportion of BSA covered with the product to the affected area was 18%. Regarding the anatomical region, Kerecis Omega3 Wound was applied 13 times to the trunk area, with most other applications involving the upper extremities, more precisely the hands (Fig. 3). The primary indication for use of the product was wound coverage in the acute setting, whereas in 6 cases, chronic wound-healing disturbances were the reason for Kerecis Omega3 Wound treatment. In the acute setting, the product was administered once, on average 6 days after trauma. In summary, detailed descriptive information on patient variables and their injury characteristics is shown in Table 1.

Fig. 1.

Types of burns, showing flame and scald burn injuries as the most common.

Fig. 2.

Depth of burn injuries treated with Kerecis Omega3 Wound, with DPTBs being the most common. SPTB, superficial partial-thickness burn.

Fig. 3.

Visualization of Kerecis Omega3 Wound applications with respect to the anatomical area: the darker the color gradient, the higher the number of applications. The highest count was observed on the hands, with 8 applications in total; the lowest count was 1 application, observed on the chin, decollete, and abdomen.

Table 1.

Patient Demographics and Injury Characteristics

Patient	Sex	Age, y	Type of Burn	ABSI	TBSA, %	Depth of Burn	BSA Covered With FSG, %	Depth of Burn Covered With FSG	BSA Covered With FSG/TBSA Rate, %	Wound	Enzymatic Debridement	Further Interventions	Complications Regarding FSG
1	M	48	CD	11	80	SPTB/DPTB/FTB	7	DPTB	9	Chronic	No	Yes
2	F	49	EB	10	60	DPTB/FTB	13	DPTB	22	Chronic	Yes	No
3	F	42	SB	9	56	DPTB	18	DPTB	32	Acute	Yes	No	Infection
4	M	41	FB	11	57	SPTB/DPTB	8.5	SPTB/DPTB	15	Acute	Yes	Yes	Hypopigmentation
5	M	53	FB	4	9	SPTB/DPTB	6	DPTB	67	Acute	Yes	No	Hypopigmentation
6	M	17	FB	9	55	SPTB/DPTB/FTB	8	FTB	15	Acute	No	Yes
7	M	58	SB	6	20	SPTB/DPTB/FTB	1	DPTB	5	Acute	Yes	Yes	Infection
8	F	40	SB	5	11	SPTB/DPTB	5	DPTB	45	Acute	Yes	No
9	M	65	SB	8	21	SPTB/DPTB/FTB	7	DPTB/FTB	33	Acute	No	Yes
10	M	78	FB	6	12.5	SPTB/DPTB	1	DPTB	8	Acute	Yes	No
11	M	59	CB	9	45	DPTB/FTB	1	FTB	2	Chronic	No	Yes
12	M	40	FB	9	60	SPTB/DPTB/FTB	6	FTB	10	Chronic	No	Yes	Contracture
13	M	17	EB	8	36.5	SPTB/DPTB/FTB	5	DPTB/FTB	14	Acute	No	Yes	Infection, contracture
14	M	30	U	7	25	DPTB/FTB	2	DPTB/FTB	8	Acute	No	No	Contracture
15	M	21	U	6	42	SPTB/DPTB/FTB	2	DPTB/FTB	5	Acute	Yes	Yes
16	M	77	SB	10	41.5	SPTB/DPTB	2	DPTB	5	Acute	Yes	No
17	M	72	FB	7	21	SPTB/DPTB/FTB	1	DPTB/FTB	5	Acute	Yes	Yes
18	M	78	CoB	6	20	SPTB/DPTB	2	DPTB	10	Chronic	No	No
19	F	53	FB	4	15	SPTB/DPTB/FTB	3	DPTB/FTB	20	Acute	No	Yes
20	M	90	SB	8	27.5	SPTB/DPTB/FTB	8	DPTB	29	Acute	Yes	Yes
21	F	34	FB	6	40	SPTB/DPTB	2.5	SPTB	6	Acute	No	No
22	F	38	u	6	32.5	SPTB/DPTB/FTB	4	FTB	12	Acute	No	Yes	Infection
23	M	42	CoB	7	30.5	SPTB/DPTB/FTB	5	SPTB/DPTB	17	Acute	Yes	No
24	F	50	U	9	44	SPTB/DPTB/FTB	10	FTB	23	Acute	Yes	Yes
25	M	38	EB	7	34	SPTB/DPTB/FTB	5	DPTB/FTB	15	Acute	No	Yes
26	F	81	FB	9	18	SPTB/DPTB/FTB	7	FTB	39	Acute	No	Yes
27	M	64	FB	12	51	SPTB/DPTB/FTB	2.5	DPTB/FTB	5	Chronic	No	No
	19:8 (M:F)	51 (SD 20.0)		8 (SD 18.2)	36 (SD 18.2)		5.3 (SD 4)		18 (SD 15)		Yes 13/no 14	Yes 16/no 11

BSA–FSG, body surface area covered with fish skin graft; CB, chemical burn; CoB, contact burn; EB, electrical burn; FB, flame burn; FSG, fish skin graft (Kerecis Omega3 Wound); SB, scald burn; SG, skin graft; SPTB, superficial partial-thickness burn; U, unknown.

Clinical Course and Outcomes

In 13 cases with DPTBs alone and DPTBs accompanied by superficial partial-thickness burns and/or small areas of FTBs, the application of Kerecis Omega3 Wound led to spontaneous wound healing, whereas additional surgical coverage by means of skin grafting or flap reconstruction was required for 12 patients. After enzymatic debridement and Kerecis Omega3 Wound application (14 cases), 6 patients needed further surgery. In cases where Kerecis Omega3 Wound was applied after surgical debridement (13 cases), 9 patients required further surgery (Fig. 4). Four out of 10 patients with DPTBs received additional skin grafting after Kerecis Omega3 Wound application. However, in all cases of FTBs, additional skin grafting, or in 1 case, flap coverage with an interosseous posterior flap on the dorsal hand, was necessary, as shown in Figure 5. Secondary surgery followed on average 16.8 days after Kerecis Omega3 Wound application. In cases of chronic wound management, 3 out of 6 patients needed further surgical treatment after Kerecis Omega3 Wound application. With respect to short-term complications, 14.8% of the patients developed local wound infections in the area treated with Kerecis Omega3 Wound. This resulted in local wound management, with topical application of iodine, rarely the use of systemic antibiotics, and in 2 cases the need for further surgical debridement. In the long-term follow-up (up to 2 y posttrauma), 2 patients who were treated with Kerecis Omega3 Wound presented with contractures in the axillary region or the first commissure of the hand, respectively. As reconstructive measures, 1 patient received surgical scar release by an anterolateral thigh (ALT) flap in the axillary region, and the other patient underwent Z-plasty procedures on the hand. Both patients with posttraumatic contractures had sustained FTBs. Two patients showed hypopigmentation of the skin in their 1-year follow-up, with otherwise good scar quality. An exemplary clinical course of a patient with spontaneous healing of a DPTB of the forearm and dorsal hand is shown in Figure 6.

Fig. 4.

Technique of debridement: 13 patients received surgical debridement, of whom 9 patients needed further skin grafting or other reconstructive measures. Fourteen patients received enzymatic debridement, of whom 6 patients needed further skin grafting.

Fig. 5.

Demonstration of the depth of burn injuries in relation to the need for further surgical interventions. SPTB, superficial partial-thickness burn.

Fig. 6.

Clinical example. A 53-year-old male patient after a flame burn with a DPTB wound on the right forearm and dorsal hand at days 0 and 6 (A and B), after 6 weeks (C), and 1 year postoperative (D).

DISCUSSION

To date, skin grafting still represents the gold standard for coverage of DPTB and FTB wounds after debridement, whereas delayed healing and formation of scar tissue are known to be associated with the development of contractures.¹⁵ Over the last few decades, various commercially available alternatives to skin grafts have been introduced for temporary or permanent burn wound coverage, including human-based (donor skin), animal-derived (eg, Integra, Kerecis Omega3 Wound), or synthetic (eg, NovoSorb BTM) products. Among these, dermal substitutes have slowly gained an important role in burn surgery. These products not only expand the treatment options for severely burned patients, but are also meant to improve long-term outcomes and quality of life. In DPTBs and FTBs, dermal substitutes can be used for early wound coverage, resulting in a decreased risk of wound infection while contributing to pain relief, accelerated wound healing, and improved scar quality. For this use of dermal substitutes in major burn injury, the term early active wound temporization has been established.¹⁶ Other, less frequent indications for dermal substitutes include injuries in specific anatomical regions (such as the back or gluteal region), religious beliefs that preclude the use of certain animal- or human-based products, or particular clinical settings such as combat zones in military medicine.^13,14

Kerecis Omega3 Wound can be used in a variety of clinical situations, as shown in Figure 7. Initial data stem from the treatment of chronic foot ulcers.^4,5,19 In this context, it seems to be effective and safe: various studies describe faster healing in refractory chronic wounds compared with conventional wound dressings.^4,17 These beneficial effects are now also used for the treatment of burn wounds. In most clinical scenarios concerning burn injuries, clinicians use the product as follows: first, in superficial defects, such as superficial partial-thickness burns or donor sites, to accelerate wound healing and reduce pain^6,7; second, for conditioning the wound bed before later grafting or to support secondary healing in DPTBs.⁶ Finally, in full-thickness defects, it may temporarily substitute the missing dermis, with subsequent definitive skin grafting, thus acting as a functional dermal substitute.

Fig. 7.

Kerecis Omega3 Wound is indicated for various types of wounds, including chronic wounds, such as diabetic foot ulcers, and acute wounds, such as burns of all degrees. EB, electrical burn; CB, chemical burn; CoB, contact burn; FB, flame burn; SB, scald burn; SPTB, superficial partial-thickness burn.^{3–7,9,17,18}

In the present study, we were able to show that 40% of patients with DPTBs and even 25% of patients with mixed burn patterns (including FTBs) healed without the need for surgery, sparing these patients donor-site morbidity and further interventions. Moreover, Kerecis Omega3 Wound may also positively influence long-term scar characteristics, supporting the findings of Wallner et al⁶ and Heitzmann et al,¹⁸ with the latter group reporting that enzymatically debrided deep dermal burns treated with Kerecis Omega3 Wound demonstrated accelerated healing and superior scar quality compared with Suprathel in a small prospective series. However, all patients with FTBs eventually required additional grafting. In contrast to DPTBs, FTBs extend through the entire dermis and thereby lack intrinsic regenerative capacity through progenitor cells, so that further surgical interventions are usually unavoidable. DPTBs, on the other hand, still contain those factors that may support re-epithelization when provided with a scaffold. Given a multifactorial background for burn wound healing, several other factors may account for the observation that not all DPTBs healed completely after treatment with Kerecis Omega3 Wound, including comorbidities, wound colonialization and infection, and the overall extent of burn trauma with a relatively high ABSI (median 7.74) in this particular patient cohort. In severe burn injury, wounds are frequently conditioned with different adjuncts, such as donor skin during the acute inflammatory phase after initial trauma, and Kerecis Omega3 Wound was used in a similar fashion in the present study. Stone et al²⁰ showed, in a preclinical setting on pig skin, no inferiority of Kerecis Omega3 Wound compared with cadaver skin as temporary coverage of affected areas, with no difference regarding skin contraction, perfusion, and hydration.

Based on our observations, Kerecis Omega3 Wound shares features of various burn wound care products rather than fitting precisely into one of the categories (biological dressing, epidermal replacement, or dermal substitute). As for its function as a dermal substitute, Kerecis Omega3 Wound seems to dissolve over time, indicating a wound-healing–boosting effect rather than integration into the wound bed, as one would expect from a genuine dermal substitute. In this context, it may act as a “functional” dermal substitute, referring to a temporary scaffold that provides structural support for tissue ingrowth but is progressively resorbed over time. Thus, histological postapplication analysis would be helpful to assess if application of Kerecis Omega3 Wound results in a neodermal layer that resembles the morphology of human dermis.

Kerecis Omega3 Wound supposedly provides an antibacterial effect^8,12,21 and may therefore show a lower infection rate in the clinical setting. In our case series, we observed an infection/colonialization rate—objectified by positive swabs—of 14.8%, which seems to be slightly below the average infection rate in severely burned patients at our burn center. However, it should be mentioned that the treatment with Kerecis Omega3 Wound represented only a small part of the overall treatment of these patients, leaving a strong possibility of the presence of confounding variables. Sepsis, nosocomial infections, and organ failure were commonly observed conditions that arose independently of local wound management. Considering the high TBSA of our burn patients and the small ratio of wound area covered by Kerecis Omega3 Wound, it is difficult to retrospectively discern wound infections originating from Kerecis Omega3 Wound–treated areas and those arising in adjacent areas treated by other techniques.

With respect to long-term outcomes, Stone et al²² showed, in preclinical trials on pig skin, improved scarring with better elasticity and reduced contractures. In our case study, 3 patients with FTBs developed contractures over the course of time, 2 in the axillary region and 1 in the hand, despite application of the product. It has to be mentioned at this point that scar contractures are a frequent occurrence in severely burned patients, with occurrences cited as high as 54%.²³

Besides its potential to induce spontaneous burn wound healing, Kerecis Omega3 Wound also has the ecological advantage of using a waste product of the fishing industry. However, despite its sustainability, material costs per surface area still remain high and present one of the limiting factors in cases of high TBSA. Taking into account that prices vary between countries, it is difficult to directly compare the costs of different products, given the wide variation in patient groups, environmental conditions, depth of defects, application methods, and treatment algorithms. In the case of Kerecis Omega3 Wound, some authors combine it with negative pressure wound treatment,²⁴ whereas others apply the product multiple times.^4,24,25 In our case series, clinical application was not directly combined with other treatments such as negative pressure wound treatment, nor was it administered repeatedly.

This study has several limitations. First, due to its retrospective design, it was not possible to establish a causal relationship between the application of Kerecis Omega3 Wound and the observed clinical outcomes. Although trends toward partial spontaneous healing and potentially reduced infection rates were noted, confounding factors such as variability in burn-depth assessment, concomitant treatments, and patient comorbidities may have influenced the results. Furthermore, the study design of a case series with a small sample size and the limited proportion of burn area covered with Kerecis Omega3 Wound, as well as the lack of an objective wound assessment, restrict the generalizability of our findings. Moreover, no validated scar assessment was performed at the time of data collection. Due to the severity of injury in the present patient cohort and the necessity of intubation during the acute phase of wound healing, assessment of pain perception using a structured and objective tool (such as patient and observer scar assessment scale) was not possible.²⁶ With respect to the incidence of scar contractures, the lack of a control group precludes definitive conclusions regarding the influence of Kerecis Omega3 Wound on long-term scar quality drawn from the current evaluation.

Based on the anecdotal experience of the authors and the current literature, Kerecis Omega3 Wound shows promise for the treatment of burn injuries and expands the armamentarium of burn wound care as a viable treatment option. In DPTBs, it can facilitate healing without further surgical intervention, thus reducing donor-site morbidity. In FTBs, Kerecis Omega3 Wound might be used for early active wound temporarization in severe burn injury, whereas the clinical efficacy for its use as a functional dermis replacement demands further evaluation. Future research directions should aim to define the precise role of Kerecis Omega3 Wound in burn care to optimize its use in selected patients and improve long-term outcomes and quality of life.

DISCLOSURES

Drs. Kim and Rittirsch serve as consultants for Kerecis. For the present work, neither has received royalties or any other type of compensation. Kerecis was not involved in the conceptualization, data acquisition, analysis, interpretation, or writing of this article at any stage. The other authors have no financial interest to declare in relation to the content of this article.

PATIENT CONSENT

Written informed consent was obtained from all participants included in the study.

ETHICAL APPROVAL

This study was approved by the local ethics committee.