Choosing the Best Approach to Wound Management and Closure

Preliminary in vivo investigation of the mesenchymal stromal cell secretome as a novel treatment for methicillin-resistant Staphylococcus aureus in equine skin wounds

OBJECTIVE

We aimed to study the antimicrobial and pro-healing potential of equine mesenchymal stromal cell secreted products (i.e. secretome), collected as conditioned media (mesenchymal stromal cell-conditioned media, MSC CM), in a novel in vivo model of methicillin-resistant Staphylococcus aureus (MRSA)-inoculated equine thorax wounds.

STUDY DESIGN

Prospective in vivo study.

ANIMALS

Two Thoroughbred geldings.

METHODS

Six full-thickness cutaneous wounds were created bilaterally on the dorsal thorax of two horses (n = 12 wounds/horse). Wounds on the left thoraces were inoculated with MRSA on day 0. All wounds were then treated with either mupirocin ointment, MSC CM, or vehicle control (n = 4 wounds per group) once daily for 3 days. Photographs were taken to quantify wound scores and sizes, as well as samples to determine bacterial colony forming units (CFUs), at days 0, 1, 2, 3, 7, 14, 21, and 28. The wound edge was biopsied on days 0, 7, and 28, and scored histologically.

RESULTS

Inoculated wounds had more bacterial CFUs at day 1 (p < .0001) and were larger in size at day 28 (p = .0009) than noninoculated wounds. Mupirocin-treated wounds were smaller than MSC CM and vehicle control-treated wounds at day 28 (p = .003). Mesenchymal stromal cell-conditioned media did not affect CFU numbers in inoculated and noninoculated wounds. Moreover, MSC CM did not affect the parameters of wound size or gross or microscopic wound scores over time.

CONCLUSION

Mesenchymal stromal cell-conditioned media did not exhibit antimicrobial or pro-healing properties in the current study; however, the in vivo model of inoculated equine thorax wounds requires further optimization.

CLINICAL SIGNIFICANCE

This pilot study contributes to a growing understanding of the equine MSC secretome as an antimicrobial and pro-healing therapeutic for equine wounds.

A novel tension relief technique to aid the primary closure of traumatic equine wounds under excessive tension

BACKGROUND

To achieve an excellent functional and cosmetic result, primary closure is preferred over leaving wounds to heal by secondary intention. However, traumatic wounds are often under excessive tension during wound closure and incorrect suture technique can compromise microcirculation, leading to skin necrosis and impaired wound healing.

OBJECTIVE

To describe an inexpensive and effective tension relief technique that helps the successful primary closure of a variety of equine wounds at high risk of dehiscence.

STUDY DESIGN

Retrospective case series.

METHODS

All wounds that were managed with the Tension Tile System (TTS) at four Equine Hospitals between March 2017 and May 2021 were evaluated. The wounds were classified according to various criteria including anatomical location, time elapsed prior to surgery, depth of wound and post-surgical use of immobilisation. Outcome criteria were based on the success of primary intention healing. The duration of convalescence (weeks) after surgery was also recorded.

RESULTS

During the study period, the TTS was used in 191/860 (22%) wounds repaired under general anaesthesia or standing sedation. Overall, primary intention healing (Group A) was achieved in 132 of 191 cases (69%, CI 62%-75%), with partial dehiscence (Group B) in a further 30/191 cases (16%, CI 11%-22%). Severe dehiscence (Group C) was recorded in 29/191 cases (15%, CI 11%-21%). The median convalescence time was 4 weeks (Range 3-15, interquartile range 4-6) in Group A.

MAIN LIMITATIONS

Retrospective nature of the study and subjective outcome assessment. The technique was applied to wounds under significant tension; however, this was based on a subjective assessment by the surgeons involved.

CONCLUSIONS

The Tension Tile System is an economical and effective technique for challenging equine wounds under tension, in a variety of anatomical locations.

The granulation (t)issue: A narrative and scoping review of basic and clinical research of the equine distal limb exuberant wound healing disorder

Exuberant granulation tissue (EGT) is often observed during second intention wound healing in horses. Despite its impact on wound care, the basic mechanisms leading to EGT are still unclear and effective strategies to prevent and/or treat EGT are lacking. The development of EGT is a poorly understood, multifactorial process involving hyperproliferating fibroblasts and malfunctional differentiation of keratinocytes, suboptimal wound contraction, dysfunctional vascularisation, and chronic inflammation. To consolidate and describe basic and clinical research literature on EGT and to identify knowledge gaps and opportunities for future research, a search was systematically conducted using predefined search terms. Subsequently, a scoping review was conducted using specific criteria to select the peer-reviewed literature that described methods to treat and/or prevent EGT. Proposed mechanisms of effects as well as results and main conclusions were extracted and tabulated. The systematic search resulted in 1062 publications in PubMed and 767 in Web of Science. Twenty additional studies were later included. Of these, 327 studies were reviewed for the narrative review on basic research and 35 controlled clinical trials were eligible for the scoping review. All 35 studies were conducted in university hospitals, and all but one involved surgically induced non-infected wounds. The study population was predominantly horses (n = 230) with a small number of ponies (n = 18) and donkeys (n = 14). In conclusion, there remains a strong need for evidence-based recommendations on EGT treatment, preferably using multi-centre studies that represent the general population of horses, include higher numbers of animals, and are performed in naturally occurring wounds. This narrative and scoping review also emphasises the importance of incorporating basic research knowledge in the study design of clinical trials.

Histopathological and mechanical effects of Ankaferd Blood Stopper® on wound healing in rats: an experimental model

Background/aim

To evaluate the histopathological and mechanical effects of Ankaferd Blood Stopper (ABS) application on wound healing.

Materials and methods

A total of 24 Wistar albino rats were randomly divided into three equal groups. In each group, a 3 cm-long midline vertical skin incision was performed in the back of the rats. In Group 1, the incision was sutured primarily. In Group 2, incision was left to secondary healing. In Group 3, ABS was applied to the incision. On the 10th day, burst pressure width was measured, and rats were sacrificed. The tissue samples were examined histopathologically. Statistical analysis was conducted with IBM SPSS program. P < 0.05 was considered significant.

Results

The mean burst pressure widths of wound separation were 13.66 ± 0.457, 7.18 ± 2.599, and 13.66 ± 1.11 mm for Groups 1–3, respectively. The difference in burst pressure width between Groups 1 and 3 was not significant (P > 0.05) but was significant between Groups 2 and 3 (P = 0.000). The vascular proliferation median values were 1, 2, and 2, for Groups 1–3, respectively. Although the difference was significant between Groups 1 and 2 in terms of vascular proliferation score (P = 0.047), no significant difference was observed between Group 3 and others. No statistically significant difference was observed among the groups in terms of collagen score, mononuclear cell infiltration, and polymorphonuclear cell proliferation (P > 0.05). The median values of fibroblast proliferation score were 1, 2, and 3, in Groups 1–3, respectively. Fibroblast proliferation score significantly differed between Groups 1 and 3 (P = 0.003).

Conclusion

ABS application results in a clean wound healing that is as strong as primary repair. However, additional studies are required to evaluate the late results of increased fibroblastic activity in the early period of ABS application alone.