Changing paradigms in lower extremity reconstruction in war-related injuries

NIR responsive scaffold with multistep shape memory and photothermal-chemodynamic properties for complex tissue defects repair and antibacterial therapy

Complex tissue damage accompanying with bacterial infection challenges healthcare systems globally. Conventional tissue engineering scaffolds normally generate secondary implantation trauma, mismatched regeneration and infection risks. Herein, we developed an easily implanted scaffold with multistep shape memory and photothermal-chemodynamic properties to exactly match repair requirements of each part from the tissue defect by adjusting its morphology as needed meanwhile inhibiting bacterial infection on demand. Specifically, a thermal-induced shape memory scaffold was prepared using hydroxyethyl methacrylate and polyethylene glycol diacrylate, which was further combined with the photothermal agent iron tannate (FeTA) to produce NIR light-induced shape memory property. By varying ingredients ratios in each segment, this scaffold could perform a stepwise recovery under different NIR periods. This process facilitated implantation after shape fixing to avoid trauma caused by conventional methods and gradually filled irregular defects under NIR to perform suitable tissue regeneration. Moreover, FeTA also catalyzed Fenton reaction at bacterial infections with abundant H2O2, which produced excess ROS for chemodynamic antibacterial therapy. As expected, bacteriostatic rate was further enhanced by additional photothermal therapy under NIR. The in vitro and vivo results showed that our scaffold was able to perform high efficacy in both antibiosis, inflammation reduction and wound healing acceleration, indicating a promising candidate for the regeneration of complex tissue damage with bacterial infection.

Long-term burden of war injuries among civilians in LMICs: case of the July 2006 war in Lebanon

Introduction

Lebanon, a country located on the eastern shore of the Mediterranean Sea, is one of the world's smaller sovereign states. In the past few decades, Lebanon endured a perpetual political turmoil and several armed conflicts. July 12, 2006, marked the start of a one-month war in Lebanon, which resulted in thousands of casualties. Little is known about the long-term consequences of war injuries inflicted on civilians during the July 2006 war.

Methods

The objectives of this paper were to identify and evaluate: 1- civilians' access to healthcare and medicine under conditions of war; 2- the long-term socioeconomic burden on injured civilians; and 3- their quality of life more than a decade post-war. We adopted a mixed-method research design with an emphasis on the qualitative component. We conducted interviews with patients, collected clinical and financial data from hospital medical records, and administered a self-rated health questionnaire, the EQ-5D-5L. Simple descriptive statistics were calculated using Excel. NVivo 12® was used for data management and thematic analysis.

Results

We conducted 25 interviews. Injured civilians were mostly males, average age of 27. The most common mechanism of injury was blast injury. Most patients underwent multiple surgeries as well as revision surgeries. The thematic analysis revealed three themes: 1- recall of the time of the incident, the thousand miles journey, and patients' access to services; 2- post-trauma sequelae and services; and 3- long-term impact. Patients described the long-term burden including chronic pain, poor mobility, anxiety or depression, and limited activities of daily living.

Discussion

Civilians injured during the July 2006 war described the traumatising events they endured during the war and the limited access to medical care during and post-war. Up until this study was conducted, affected civilians were still experiencing physical, psychological, and financial sequelae. Acknowledging the limitations of this study, which include a small sample size and recall bias, the findings underscore the necessity for the expansion of services catering to civilians injured during wartime.

The impact of the gut microbiome on toxigenic bacteria

Millions of symbiotic and pathogenic microorganisms known as microbiota colonize the host body. The microbiome plays an important role in human health and colonizes hundreds of different species of multicellular organisms so that they are introduced as the metaorganisms. Changes in the microbial population of the gut microbiome may cause resistance to pathogenic bacteria-induced infection. Understanding the principles of Host-Microbiota Interactions (HMIs) is important because it clarifies our insight towards the mechanisms of infections established in the host. Interactions between the host and the microbiota help answer the question of how a microorganism can contribute to the health or disease of the host. Microbiota can increase host resistance to colonization of pathogenic species. Studying the HMIs network can in several ways delineate the pathogenic mechanisms of pathogens and thereby help to increase useful and novel therapeutic pathways. For example, the potentially unique microbial effects that target the distinct host or interfere with the endogenous host interactions can be identified. In addition, the way mutations in essential proteins in the host and/or in the microbes can influence the interactions between them may be determined. Furthermore, HMIs help in identifying host cell regulatory modules.

A Scarless Healing Tale: Comparing Homeostasis and Wound Healing of Oral Mucosa With Skin and Oesophagus

Epithelial tissues are the most rapidly dividing tissues in the body, holding a natural ability for renewal and regeneration. This ability is crucial for survival as epithelia are essential to provide the ultimate barrier against the external environment, protecting the underlying tissues. Tissue stem and progenitor cells are responsible for self-renewal and repair during homeostasis and following injury. Upon wounding, epithelial tissues undergo different phases of haemostasis, inflammation, proliferation and remodelling, often resulting in fibrosis and scarring. In this review, we explore the phenotypic differences between the skin, the oesophagus and the oral mucosa. We discuss the plasticity of these epithelial stem cells and contribution of different fibroblast subpopulations for tissue regeneration and wound healing. While these epithelial tissues share global mechanisms of stem cell behaviour for tissue renewal and regeneration, the oral mucosa is known for its outstanding healing potential with minimal scarring. We aim to provide an updated review of recent studies that combined cell therapy with bioengineering exporting the unique scarless properties of the oral mucosa to improve skin and oesophageal wound healing and to reduce fibrotic tissue formation. These advances open new avenues toward the ultimate goal of achieving scarless wound healing.

Extremity soft tissue coverage in the combat zone: use of pedicled flap transfers by the deployed orthopedic surgeon

BACKGROUND

In theaters of operation, military orthopedic surgeons have to deal with complex open extremity injuries and perform soft-tissue reconstruction on local patients who cannot be evacuated. Our objective was to evaluate the outcomes and discuss practical issues regarding the use of pedicled flap transfers performed in the combat zone on local national patients.

METHODS

A retrospective study was conducted on data from patients treated by a single orthopedic surgeon during four tours in Chad, Afghanistan and Mali between 2010 and 2017. All pedicled flap transfers performed on extremity soft-tissue defects were included, and two groups were analyzed: combat-related injuries (CRIs) and non-combat related injuries (NCRIs).

RESULTS

Forty-one patients with a mean age of 25.6 years were included. In total, 46 open injuries required flap coverage: 19 CRIs and 27 NCRIs. Twenty of these injuries were infected. The mean number of prior debridements was significantly higher in the CRIs group. Overall, 63 pedicled flap transfers were carried out: 15 muscle flaps, 35 local fasciocutaneous flaps and 13 distant fasciocutaneous flaps. The flap types used did not differ for CRIs or NCRIs. Complications included one flap failure, one partial flap necrosis and six deep infections. At the mean follow-up time of 71 days, limb salvage had been successful in 38 of the 41 cases. There were no significant differences between CRIs and NCRIs in terms of endpoint assessment.

CONCLUSIONS

Satisfying results can be achieved by simple pedicled flaps performed by orthopedic surgeons deployed in forward surgical units. Most complications were related to failure of bone infection treatment. The teaching of such basic reconstructive procedures should be part of the training for any military orthopedic surgeon.

TRIAL REGISTRATION

Retrospectively registered on January 2019 (n°2019-090 1-001).

Multidisciplinary Application of an External Tissue Expander Device to Improve Patient Outcomes: A Critical Review

Significance: Continuous external tissue expansion (CETE) is a versatile tool in soft tissue injury management, and could be an addition to the traditional reconstructive ladder.

Recent Advances: This critical review discusses the principles and application of CETE, covering a company-sponsored consensus meeting on this emerging technology and highlighting the DermaClose^® (Synovis Micro Companies Alliance, Inc., Birmingham, AL) device's unique approach to soft tissue injury management. There is clinical evidence to support the use of CETE in the management of a number of wound types, including fasciotomy, trauma, amputation, and flap donor sites. The device can be applied to open wounds, potentially avoiding the need for a skin graft or other more complex or invasive reconstruction options. DermaClose applies constant tension without restricting blood flow and does not require repeated tightening.

Critical Issues: CETE is becoming more widely used by surgeons of different specialties, and numerous reports describing its efficacy and safety in wound management have been published. Surgeons using CETE must follow the correct technique and select patients carefully to achieve optimal outcomes. However, there is no single source of information or consensus recommendations regarding CETE application.

Future Directions: Prospective evidence on the efficacy and safety of CETE in clinical practice is required to communicate the best techniques and share important experiences. This will help to solidify its place in the reconstructive ladder as a valuable additional option for surgeons.

Successful Treatment of War Zone Traumatic Lower Extremity Wound With Exposed Tendons Using an Autologous Homologous Skin Construct

Extremity injuries are common in contemporary combat and have become more prevalent as fatality rates have dropped to historic lows. Traumatic extremity wounds, especially those sustained in theater, often present with exposed structures such as tendon, bone, and joint, preventing the use of split-thickness skin grafts (STSG) for coverage. Traditional reconstructive options for these complex wounds include skin substitute with delayed STSG, local flaps, debridement of tendons, pedicled distant flaps (such as cross-leg flap), free tissue transfer, and amputation. STSG, whether on top of skin substitutes or after tendon debridement, can result in contracture and functional limitations in the extremities. Flap reconstructions require prolonged procedures, hospital stays, and periods of immobility. As an alternative to traditional reconstructive options, an autologous homologous skin construct (AHSC) uses a small full-thickness elliptical skin harvest from the patient, which is sent to a biomedical manufacturing facility, processed into AHSC, and can be returned and applied to a wound bed as soon as 48 hours after harvest and used up to 14 days after harvest. We present in this case report the treatment of a 42 cm² complex dorsolateral ankle wound with exposed tendons in an active duty soldier following a rollover motor vehicle accident sustained in theater. After application of AHSC, the soldier’s wound closed in nine weeks with pliable, sensate skin. The patient retained function without contractures limiting ankle motion or adhesions limiting tendon gliding. The successful treatment of this complex war zone injury with AHSC has allowed the soldier to quickly participate in unrestricted physical therapy and is on a trajectory for near-term return to active duty.

Combat vascular injury: Influence of mechanism of injury on outcome

BACKGROUND

Haemorrhage is the leading cause of death on the battlefield. Seventy percent of injuries are due to explosive mechanisms. Anecdotally, these patients have had poorer outcomes when compared to those with penetrating mechanisms of injury (MOI). We wished to test the hypothesis that outcomes following vascular reconstruction were worse in blast-injured than non blast-injured patients.

METHODS

Retrospective cohort study. British and American combat casualties with arterial injuries sustained in Iraq or Afghanistan (2003-2014) were identified from the UK Joint Theatre Trauma Registry (JTTR). Eligibility included explosive or penetrating MOI, with follow-up to UK hospital discharge, or death. Outcomes were mortality, amputation, graft thrombosis, haemorrhage, and infection. Statistical analysis was performed using Pearson Chi-Square test, t-tests, ANOVA or non-parametric equivalent, and survival analyses.

RESULTS

One hundred and fifteen patients were included, 80 injured by explosive and 35 by penetrating mechanisms. Evacuation time, ISS, number of arterial injuries, age and gender were comparable between groups. Seventy percent of arterial injuries resulted from an explosive MOI. The explosive injuries group received more blood products (p = 0.008) and suffered more regions injured (p < 0.0001). Early surgical interventions in both were ligation (n = 36, 31%), vein graft (n = 33, 29%) and shunting (n = 9, 8%). Mortality (n = 12, 10%) was similar between groups. Differences in limb salvage rates following explosive (n = 17, 53%) vs penetrating (n = 13, 76.47%) mechanisms approached statistical significance (p = 0.056). Nine (28%) vein grafted patients developed complications. No evidence of a difference in the incidence of vein graft thrombosis was found when comparing explosive with non-explosive cohorts (p = 0.154).

CONCLUSIONS

The recorded numbers of vein grafts following combat arterial trauma in are small in the JTTR. No statistically-significant differences in complications, including vein graft thrombosis, were found between cohorts injured by explosive and non-explosive mechanisms.

Beneficial effects of a novel shark-skin collagen dressing for the promotion of seawater immersion wound healing

BACKGROUND

Wounded personnel who work at sea often encounter a plethora of difficulties. The most important of these difficulties is seawater immersion. Common medical dressings have little effect when the affected area is immersed in seawater, and only rarely dressings have been reported for the treatment of seawater-immersed wounds. The objective of this study is to develop a new dressing which should be suitable to prevent the wound from seawater immersion and to promote the wound healing.

METHODS

Shark skin collagen (SSC) was purified via ethanol de-sugaring and de-pigmentation and adjusted for pH. A shark skin collagen sponge (SSCS) was prepared by freeze-drying. SSCS was attached to an anti-seawater immersion polyurethane (PU) film (SSCS + PU) to compose a new dressing. The biochemical properties of SSC and physicochemical properties of SSCS were assessed by standard methods. The effects of SSCS and SSCS + PU on the healing of seawater-immersed wounds were studied using a seawater immersion rat model. For the detection of SSCS effects on seawater-immersed wounds, 12 SD rats, with four wounds created in each rat, were divided into four groups: the 3rd day group, 5th day group, 7th day group and 12th day group. In each group, six wounds were treated with SSCS, three wounds treated with chitosan served as the positive control, and three wounds treated with gauze served as the negative control. For the detection of the SSCS + PU effects on seawater-immersed wounds, 36 SD rats were divided into three groups: the gauze (GZ) + PU group, chitosan (CS) + PU group and SSCS + PU group, with 12 rats in each group, and two wounds in each rat. The wound sizes were measured to calculate the healing rate, and histomorphology and the immunohistochemistry of the CD31 and TGF-β expression levels in the wounded tissues were measured by standard methods.

RESULTS

The results of Ultraviolet-visible (UV-vis) spectrum, Fourier-transform infrared (FTIR) spectrum, circular dichroism (CD) spectra, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and amino acid composition analyses of SSC demonstrated that SSC is type I collagen. SSCS had a homogeneous porous structure of approximately 200 μm, porosity rate of 83.57% ± 2.64%, water vapor transmission ratio (WVTR) of 4500 g/m², tensile strength of 1.79 ± 0.41 N/mm, and elongation at break of 4.52% ± 0.01%. SSCS had significant beneficial effects on seawater-immersed wound healing. On the 3rd day, the healing rates in the GZ negative control, CS positive control and SSCS rats were 13.94% ± 5.50%, 29.40% ± 1.10% and 47.24% ± 8.40%, respectively. SSCS also enhanced TGF-β and CD31 expression in the initial stage of the healing period. The SSCS + PU dressing effectively protected wounds from seawater immersion for at least 4 h, and accelerated re-epithelialization, vascularization and granulation formation of seawater-immersed wounds in the earlier stages of wound healing, and as well as significantly promoted wound healing. The SSCS + PU dressing also enhanced expression of TGF-β and CD31. The effects of SSCS and SSCS + PU were superior to those of both the chitosan and gauze dressings.

CONCLUSIONS

SSCS has significant positive effects on the promotion of seawater-immersed wound healing, and a SSCS + PU dressing effectively prevents seawater immersion, and significantly promotes seawater-immersed wound healing.