Limited added value of negative pressure wound therapy compared with calcium alginate dressings for second intention healing in a noncontaminated and contaminated equine distal limb wound model

The Best Protocol to Treat Equine Skin Wounds by Second Intention Healing: A Scoping Review of the Literature

Equine skin wound treatment continues to be a challenge for veterinarians. Despite being a frequent practice, it remains difficult to choose an evidence-based treatment protocol. This study aimed to comprehensively explore the literature and provide a scoping review of therapeutic strategies for equine skin wounds and identify knowledge gaps and opportunities for future research. This review was conducted using specific criteria to select literature that described methods to manage second intention wound healing. After removing duplicates and screening papers for suitability, 81 manuscripts were included for data extraction. Of these, 59 articles were experimental studies, 10 were case reports, 9 were case series, and 3 were clinical studies. The most frequent wound location was the distal limbs. Macroscopic assessment was the main tool used to evaluate treatment effectiveness. All of the case reports, case series, and clinical studies reported positive outcomes with regard to the treatment used, while only 36% of the experimental studies found significant healing improvement in treated wounds compared to control groups. It was found that there are many treatments that have exhibited controversial results, and there exists a lack of evidence for the adoption of specific treatment protocols.

Negative-Pressure Wound Therapy (NPWT) in Horses: A Scoping Review

Obtaining a healthy wound environment that is conductive to healing in horses can be challenging. Negative-pressure wound therapy (NPWT) has been employed in humans to enhance wound healing for decades. The existing evidence for the effectiveness of NPWT remains uncertain in equine medicine. The aim of this review is to investigate NPWT applications and benefits in horses. A scoping review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines for scoping reviews on three databases (PubMed, Web of Science-Thompson Reuters, and Wiley Online Library). Twenty-four manuscripts were considered. After removing duplicates, 17 papers underwent abstract screening. Of these, 16 + 1 (cited by others) were evaluated for eligibility according to PICOs, including no case reports/retrospective studies, four original articles, and three reviews. Fifteen manuscripts met the inclusion criteria. The focus of the articles was wound management; they included three reports of wounds communicating with synovial structures. Traumatic wounds and surgical-site infections are indications for NPWT. NPWT presents several advantages and few complications making it an attractive alternative to conventional wound management. However, randomized controlled trials should be performed to quantify the benefits and establish precise protocols in horses.

High Numbers of CD163-Positive Macrophages in the Fibrotic Region of Exuberant Granulation Tissue in Horses

Exuberant granulation tissue (EGT) is a frequently encountered complication during second intention healing in equine distal limb wounds. Although it is still unknown what exactly triggers the formation of this tissue, previous research has revealed a persistent inflammatory response in these wounds. In this preliminary study we examined this inflammatory response in EGT-developing wounds as well as in experimental induced wounds. Immunohistological stainings were performed to detect primary inflammatory immune cells (MAC387 staining) as well as pro-resolution immune cells (CD163 staining). Our results show a significantly higher amount of MAC387+ and CD163+ cells in the fibrotic regions of EGT compared with the 19-day-old experimental wounds. This persistent high amount of fibrosis-promoting CD163+ cells in EGT suggests that the wound healing processes in EGT-developing wounds are arrested at the level of the proliferation phase.