Modified intermittent low negative pressure wound therapy for complex injuries: A case series

Abstract

Introduction and importance

Combat wounds can be difficult to manage and can lead to disfigurement and infection. The closure of these wounds is crucial, as delayed closure also increases the risk of further complications. Military medicine has introduced negative pressure wound therapy, which modulates wounds perfectly through the microscopic and macroscopic configurations of the wound environment. It is expensive and not available worldwide, and several modifications using low cast materials were mentioned in literature.

Methods

We present a case series of four patients using the previously mentioned modified technique in combat wound management, and discuss the results, outcome, and justification for choosing this modality of treatment. All patients underwent a thorough debridement, followed by a modified negative pressure wound treatment for three weeks, employing readily available medical devices.

Results

All wounds healed successfully without complication and a simple closure was used to cover the resultant wound.

Conclusion

Modified NPWT with limited resources is capable of promoting healing in conflict-related wounds through multifactorial properties and transforming reconstructive methods from complex to simple procedures in areas with a shortage of medical supplies and surgeons in addition to busy operating rooms.

Highlights

• •Combat injuries are destructive and wound at high risk of infection and delayed reconstruction is advisable but open wound pose significant morbidities.
• •Negative pressure wound therapy was used since decades and proved it's effectiveness, but high cost and shortage of materials are drawbacks so modification was created to obtained advantages of NPWT with low case limited resources.
• •Modified NPWT can be uesd in military medicine and it provided optimal condition for wound healing.

1. Introduction

A wound is simply defined as a disruption of tissue continuation with different aetiology, and it can have a significant impact on the individual if it is not well treated. Healthcare systems invest in human and financial resources to provide the optimal environment for wound healing. Despite the numerous physiological processes of healing described in the literature for centuries, recent research and trials have introduced an optimal environment to enhance the healing process. Besides several factors, necrotic tissue, foreign bodies, and environmental acquired infection must be eliminated to ensure boosted wound closure [1]. War-related injuries are widely regarded as the most contentious injuries due to their inherited morbidity and challenging management. Wound complicity, fragment invasion, environmental microbial load, the delay for reaching healthcare facilities, and a shortage of equipment and personnel expertise make these wounds challenging [2].

Although negative pressure wound therapy is not a new technology, it is used to modify factors for healing promotion. The advantages of this technique have successfully been utilized as a potent complement to wound therapy, and it has also been introduced to military medicine. NPWT is considered to be expensive worldwide, which suggests that medical providers have limited resources for modification of this technique. The literature provided an explanation for several conversions, and all of them were deemed successful accomplishments [[2], [3], [4]].

The application of NPWT facilitates the creation of balanced conditions in wounds by utilizing suction of exudate and subsequent drainage of infection, while simultaneously creating a shield to prevent excessive evaporation. Furthermore, negative energy promotes vascularity in wounds and lymphatic drainage. The treatment improves the limbs shape and reduces edema, in order to simulate pre-injury status. These factors hold significant importance in the healing and viability of wounds, as evidenced by the regeneration of tissue and the inhibition of infection. The observation of infrequent dressing changes is appreciated by patients, hence compliance with management and promotes satisfaction [4].

As this report originates from a conflict zone in a low-income nation, the efficacy of standard NPWT is deemed unfeasible due to numerous factors, including a dearth of dressing material, negative pressure generator machines, and power supplies. Therefore, we modified the technique to meet our requirements, transforming a complex wound into a simple one.

2. Materials and methods

We report the case of four patients with combat injuries as a retrospective, multi-center, and consecutive study. All patients who presented to the plastic surgery unit with combat limb injuries during the period from April 2023 to September 2023 and consented to be managed by Modified intermittent Negative Pressure Wound Therapy were included.

A 39-year-old man was injured by a gunshot to his right arm, which caused a humeral fracture and a large degloving injury to the posterior aspect of the shoulder. During the examination, it was determined that the wound was situated at the posterior aspect of the right shoulder, and it was measured to be approximately 10 ∗ 6.5 cm in size, extending from the prominent shoulder to the scapular spine, with an irregular margin. The wound bed was occupied by necrotic muscles, which were encased in a thick layer of exudate. He underwent skeletal fixation with an external fixator and underwent debridement of the shoulder wound. The wound was then debrided again, followed by the installation of modification NPWT. For a month, the wound dressing was changed every 5 days. The wound healed uneventfully, apart from a patch of raw skin.

After receiving a gunshot, a 55-year-old man was presented to the hospital with a wound to the medial aspect of the left thigh. After a week of trauma, he presented. After stabilization, he underwent an examination under anaesthesia. His thigh's medial compartment was examined and revealed necrotic tissue (skin, subcutaneous tissue, gracilis and adductor muscles) with no vascular involvement. He underwent debridement, and the wound that resulted was approximately 24 ∗ 5 ∗ 8 cm. Subsequently, a modified NPWT was administered. For the next three weeks, the wound dressing was changed weekly. After the discontinued NPWT, a delayed primary closure was used to close the wound.

A 26 years old man sustained a gunshot wound to his upper medial aspect of bilateral limbs. Besides devitalized tissue (upper gracilis muscle), there are also metallic particles invading the tissue. The wound was located about 6 cm below and later to the groin crease and was found to be dirty. He underwent debridement, and the wound was estimated to be approximately 12 ∗ 10 ∗ 5 cm. The modification NPWT was also implemented, and the interval between dressing changes was extended to 10 days. After three weeks, granulation tissue had formed in the cavity and the wound had closed.

A 30-year-old man suffered trauma to his left foot from a combat injury that caused metatarsal fractures and loss of dorsum skin. He underwent fixation of the fracture using K.wire and debridement in one session. A week later, he underwent another session of debridement, which resulted in metatarsal exposure and a wound that measured 9 ∗ 7 cm. Consequently, the modification NPWT was used. The duration of application of NPWT was extended to 14 days without any change to the wound dressing after the first 7 days. After three weeks, the dorsum of the left foot was covered with a split-thickness skin graft.

As previously mentioned, all patients underwent debridement of the wound and meticulous hemostasis, in addition to receiving antibiotic therapy for a duration of one week. Debridement and instillation of our modified NPWT took place at the same session with different teams. For this technique, adhesive dressing/nylon foils, surgical gauze (15 ∗ 15 cm), sponge, nasogastric tube size 18, Vaseline gauze, and adhesive tape were used (Fig. 1).

Fig. 1.

Materials used for modified NPWT: nasogastric tube, surgical sponge, surgical gauze and suction drain.

After debridement, the wound was resurfaced with gauze as the first layer, followed by the application of a sponge, which was transversely longitudinal with the nasogastric tube as the second layer. Vaseline gauze was disturbed at the edges of the wound, and ultimately surgical gauze was employed to cover the wound. The utilization of the interval sponge was employed to enhance the absorption of exudates within cavities. The intact skin was encased with surgical gauze after nylon foil was employed. Subsequently, the tube was connected to the negative pressure generator at −100 for a duration of 30 min, and finally, the tube was connected to a suction surgical drain that continues to maintain negative pressure. After disconnecting the tube from the machine, the pressure slightly changed, but the negative pressure was maintained. Both the wound dressing and suction drain were depressed for periods of therapy.

This work has been reported in line with PROCESS checklist guidelines [12].

3. Result

All of the wounds were successfully transformed from complex to simple, and they were ultimately covered by straightforward reconstruction techniques. Furthermore, the size of the wound was significantly diminished, and the wound beds were found to be well vascularized and moist, without any fluid accumulation even within cavities. In the first patient, the wound size was reduced significantly and rapidly until completely healed, except for a small area left to heal by secondary intention (Fig. 2). Second patient had a medial compartment of the thigh that was completely filled with granulation tissue. This allowed for simple closure (Fig. 2). In the third patient, there were problems with weapon particles that invaded tissues, although the wound was not as large as in the second patient (Fig. 3). In this particular patient, negative pressure gradually acts as a magnet to extract most of these particles, while the wound still shrinks (Fig. 4). This technique was applied to a raw fractured bone in the last patient, but healing occurred uneventfully and the desired outcome was achieved (Fig. 5). All patients were observed for 24 h after surgery and after the application of the modified technique, before being discharged from hospital.

Fig. 2.

Case (1): Wound at right shoulder extended to arm.

a. Second debridement after arrival from orthopaedic department.

b. Application of modified NPWT.

c. Wound after a month of NPWT, healed apart from linear raw area.

Fig. 3.

Case (2): Rt thigh wound.

a. Initial presentation and wound bed was occupied by devitalised tissue.

b. Wound after initial debridement.

c. Wound 3 weeks later after modified NPWT.

d. Delayed primary closure of wound after 3 weeks.

Fig. 4.

Case (3): Bilateral upper thigh wounds.

a. Initial presentation, showing destructed tissue.

b. X-ray of right thigh showing weapon fragments invading thigh.

c. Wound after 3 weeks of modified NPWT.

d. Wounds successfully were closed primary.

Fig. 5.

Case (4): Left foot open fracture (metatarsals fracture).

a. Initial presentation showing tissue disruption of dorsum of foot.

b. Showing wound after debridement and fixation by k. wire.

c. Application of modified NPWT.

d. Wound after 3 weeks was covered by meshed split thickness skin graft.

4. Discussion

NPWT is a healing promoter technique, and since it was introduced into medical practice, many wounds have been managed easily. As medical technology advances, this technique has undergone modifications, and supplementary materials such as dermal matrix have been employed to expedite healing and restore patients to their pre-injury condition. This has resulted in a heightened quality of life and a reduction in the burden on the healthcare system. The benefits of applying negative pressure to a wound are evident in the wide utility of this technique on a variety of wounds, as modalities of management or prophylactic to avoid complications [5].

Combat injuries are presented in different forms and are present on multiple sites, and are characterized by complicity and are difficult to repair. With the introduction of negative pressure wound therapy to military medicine, limb salvage and wound healing became possible. Although NPWT still has limitations regarding installation and availability. All of our patients were injured by military weapons at different sites, and initial debridement was forced towards flap reconstruction. This technique was used as a temporary method for wound cover preparation, but it simplified the management.

In the first patient, the shoulder defect healed completely, while the first option was to cover the exposed scapula with a flap. The second patient's medial compartment of the thigh becomes a cavity after debridement, and a bulk of tissue will be needed to fill it. However, this technique will eventually lead to a delayed primary closure. In the third patient, the wounds were located in areas with a moist environment in the groin and proximity to genitalia. The decision was changed from flap cover and successful closure was attempted primary. The procedure of resurfacing the dorsum of the foot is typically accomplished by utilizing a flap technique to safeguard tendons and prevent bone necrosis. Previously, NPWT was not utilized over bone. However, in our case, granulation was observed through the application of the technique over both bone and tendons. Usage of NPWT over exposed bone as we did in the first and last patient was supported by Uwakwe C Mba et al. who illustrated management of 17 wounds with exposed bone using modified NPWT [3,6].

Furthermore, wound infection is an obstacle to achieving wound healing, and war-injuries are considered contaminated. Therefore, the infection rate is double, and environmental acquired infections are an addictive risk. This technique not only reduced bacterial burdens but also served as a shield to isolate the wound from environmental infection, resulting in antibiotic usage being restricted to a duration of one week. Despite the increase in the interval between dressing changes, the wounds remain without infection. Recent studies have elucidated the utilization of antibiotics as a solution and sponge for wounds situated adjacent to the application of NPWT [2,4]. In the third patient, we consider weapon particles as a potential source of infection, resulting in a delay in closure and a superior utilization of NPWT over flap cover. This is a unique use of negative pressure to extract foreign material if it is not surrounded by neurovascular structures.

The materials used for modification are available at all healthcare facilities, and several studies have mentioned their effectiveness. They consider negative pressure (75 _ 125 mmHg) sufficient to promote wound healing. In our case, the same described materials were used, but the pressure was modified due to a shortage of pressure generator and electric maintenance. For 30 min, a suction machine created negative pressure (-100 mmHg) and after ensuring that the system was sailing, suction diverged and continued by suction drain [[7], [8], [9]]. Suction drain was used to maintain negative pressure, and it allowed early discharge from hospital, therefore hospital stay was reduced significantly to 4 days if four-cycles were needed.

Despite the advantages of NPWT, complications can develop and lead to discontinuation of management. Even so, they are infrequent. The complications manifested as pain, infection, bleeding, and skin blisters, and a few reports even mentioned limb ischemia. Out of all the aforementioned side effects, pain is the sole issue we encounter. Pain associated with the initiation of management is well tolerated by patients within the first few days, and simple analgesia solves this problem. The management of NPWT may be complicated by infection due to a variety of factors, including prolonged use, low suction pressure, and high exudate formation. Additionally, military wounds are associated with multi-drug resistant and invasive fungal infections [10,11]. Despite the infrequent changes in wound dressing, our patients have not developed any wound infections or skin blisters.

5. Conclusion

The modified intermittent NPWT, which was developed with limited resources and low pressure, exhibits the ability to promote healing in war wounds through multifactorial properties. It can also transform reconstructive procedures from complex to simple, even in areas with a scarcity of medical supplies and surgeons in addition to busy operating rooms.

Consent

Written informed consent was obtained from the patient for publication and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

Patient confidentiality maintained and data collected after full explanation of research project and aim of it, then written informed consent was obtained and this adherent to national ethical committee (NEC11/2002) and Elnou hospital ethical committee, Khartoum, Sudan. 2/6/2023.

Funding

No fund received.

Author contribution

I confirm that all the authors have made a significant contribution to this manuscript, have seen and approved the final manuscript and have agreed to its summation. Also I accept full responsibility for the work and the conduct of study, have access to data, and controlling the decision of publishing.

Guarantor

Dr. Momen Mahmoud Ibrahim Mohamed.

Research registration number

No trial or experiment involved human subjects.

Conflict of interest statement

No conflict of interest.