Innovative Outlook to Negative Pressure Wound Therapy: A Cost-Effective Solution for Broader Availability

Wound management has been one of the most challenging aspects of clinical care for centuries. From open surgical wounds to diabetic ulcers, healthcare professionals face the constant challenge of finding effective treatments. Despite numerous advancements, wound care remains a critical global concern, impacting healthcare systems across developed and developing nations. The burden on resources—including time, workforce, materials, and finances—continues to be immense, emphasizing the need for more efficient, accessible, and affordable solutions.

Among various wound care methods, Negative Pressure Wound Therapy (NPWT) has emerged as a game-changer. While it has proven effective across multiple specialties, including orthopedics, plastic surgery, and cardiovascular surgeries, the high cost of conventional NPWT technologies has limited its widespread adoption, especially in general hospitals and resource-constrained settings.

The Basics of NPWT: A Simple Yet Effective Solution

NPWT is a technique that uses controlled negative pressure to promote wound healing. The treatment involves placing a section of polyurethane foam with an open-cell structure directly into the wound. A tube drain, typically with a flat cup, is placed over the foam. The entire area is sealed with a transparent adhesive membrane securely fixed to the skin around the wound margin, creating an airtight seal. The tube is then connected to a vacuum source, creating controlled negative pressure.

This system facilitates fluid drainage from the wound, removes interstitial fluid, reduces localized edema, and promotes blood flow. Notably, the foam ensures that the entire wound surface is uniformly exposed to negative pressure, preventing occlusion or localized high-pressure areas that could cause tissue necrosis. The result is faster healing, reduced bacterial growth, and better tissue perfusion.

The intermittent negative pressure leads to mechanical tissue deformation, stimulating the synthesis of proteins and matrix molecules while promoting angiogenesis. This process is crucial for tissue regeneration and wound healing.

A Breakthrough in Tendon Coverage

Another critical feature of NPWT is its ability to sustain consistent blood flow by avoiding capillary autoregulation mechanisms that can otherwise hinder healing. Intermittent pressure allows cells to rest, undergo mitosis, and continue their cycle of growth and division, which is vital for tissue repair. For this reason, cyclical negative pressure is considered the most effective mode of wound healing.

One of the most remarkable outcomes of using NPWT is its ability to support the formation of granulation tissue over exposed tendons. Historically, such tendon exposure was a significant challenge, often leading to the sacrifice of tendons before skin grafting.

The High-Cost Barrier

Despite its effectiveness, NPWT technology has remained largely out of reach for many healthcare institutions due to its high cost. Traditional NPWT systems require complex machinery, and each device is designed for a single patient. This limits its scalability, especially in busy general hospitals. Furthermore, the cost of the machines, consumables, and ongoing maintenance makes it difficult for many healthcare settings to provide NPWT as a standard treatment option. 

A Cost-Effective Solution: Replicating NPWT with Hospital Resources

Motivated by the need to reduce costs while still offering the benefits of NPWT, a team of clinicians, along with researchers from the Chemical Engineering Department at BVDU, embarked on a mission to develop a more affordable solution. Leveraging the hospital's existing resources, the team replaced expensive components with commonly available materials.

To replace the expensive core components of a traditional NPWT, our team used:

1. Commonly available PU foam: The team conducted rigorous chemical and biological compatibility studies, including cytotoxicity studies, to ensure safety. After testing several samples, a specific PU foam was selected based on favourable results.

2. Ioban Antimicrobial Drape: A self-adhesive, transparent film commonly used in surgeries to isolate the operating field.

3. Ryel's tube: A non-collapsible tube with lateral perforations at the distal end used for draining fluids.

4. Collection jars at vacuum outlets: A central suction system utilized to maintain continuous negative pressure across multiple patients instead of individual vacuum machines.

   
   

Simplifying the Setup

Central suction outlets are a standard requirement at most indoor clinical facilities. Each outlet is equipped with sterilized canisters, a pressure gauge, a control valve, and an inlet cock. The pressure gauge and valve helped set sub-atmospheric pressure in the range of 0 to 200 mm of Hg, with slight fluctuations, replacing the need for expensive negative pressure-generating devices. Also, the patient can disconnect or reconnect the tube from the canister whenever desired, improving mobility and overall experience.

Testing and Results

In practice, this modified NPWT system was successfully used to treat a variety of wounds, including fresh lacerations, diabetic foot ulcers, abscess cavities, postoperative wounds, and laparotomy sites. The treatment was administered using a continuous negative pressure mode. Though a cyclical mode is commonly used, the continuous negative pressure mode presented improved offerings.

A study record was kept regarding the volume of the fluid drained, its colour, the culture and sensitivity of the drained fluid, tissue biopsies/colony counts, wound volume calculations, and photographs to assess the change in size and development of granulation tissue.

The modified NPWT cost per patient for a four-day dressing cycle was only Rs. 350, compared to the traditional system, which costs Rs. 7,000 for the same period. Furthermore, the central suction in any hospital is operational 24/7, so there is no additional capital expenditure. This dramatic reduction in cost makes the treatment accessible to a broader population and is a significant breakthrough for healthcare systems with limited budgets.

The second most important benefit of this exercise is that a clinician can simultaneously administer treatment to multiple patients at a given time, introducing the mass application of the technique.

Future Directions

The new NPWT system is developing, and plans are underway to design a timer device for cyclical pressure applications. This timer would replicate the features of commercial systems, which offer both modes of negative pressure applications. By improving the precision of the pressure cycles, the system could further optimize healing while maintaining its low cost.

Additionally, efforts are being made to standardize the sterilization process for the materials used in the NPWT system. Steam sterilization would be an established mode for sterilizing polyurethane foam. This method is both practical and time-efficient. It ensures the foam maintains its integrity while avoiding the long processing times associated with traditional methods like ethylene oxide (ETO) sterilization.

Conclusion

Negative Pressure Wound Therapy, combined with innovative, cost-effective solutions, represents a paradigm shift in wound care. This approach provides a viable alternative to high-cost commercial systems, significantly reducing the financial burden on patients and healthcare systems by utilizing existing resources and clinician ingenuity. The ability to treat multiple patients simultaneously using hospital infrastructure further enhances the cost-effectiveness of this system.

As this model is scaled and refined, it has the potential to revolutionize wound management, making advanced care more accessible for everyone. With continued research and innovation, this ingenious approach to NPWT can be deployed as a global solution to the widespread issue of high-cost wound care, improving patient outcomes and reducing healthcare costs worldwide.