Case Study 1:
Clinical application of the ITI Wound Treatment System with irrigation in 10 Patients with lower-extremity chronic wounds
Introduction
Ulcerations of the lower extremities that fail to heal affect millions of people in the United States and across the world. These wounds impose medical, psychosocial, and financial hardships. As the U.S. population's rising number of older citizens experience age-related illnesses, healthcare professionals see these types of wounds - accompanied by chronic and debilitating disorders - at an increasing rate. Their treatment is costly, averaging $37,800 per patient, depending on treatment modality and length of care. Current overall U.S. healthcare costs for chronic wound treatment are estimated at $20 billion per year. Medicare expenditures for lower-extremity ulcer patients are currently, on average, 3 times higher than general expenditures for Medicare patients. Of course expense alone does not encompass the distress caused by chronic wounds.
The etiology of chronic wounds includes pressure injury, metabolic disturbance, trauma, venous and arterial insufficiency, as well as diabetic neuropathy. Studies demonstrate that an increase in matrix metalloproteinases (MMPs) inhibits tissue healing - as demonstrated by patients with diabetes. Many diabetic patients present decreased blood flow and suppressed ability to fight infection. Wound healing is also inhibited by smoking or the intake of "smokeless" nicotine substances. Nicotine causes vasoconstriction, a significant factor in the failure of wounds to heal.
Whatever their etiology, chronic wounds, if insufficiently addressed, can become a major source of medical distress - leading to amputation or life-threatening complications. Researchers have long looked for ways to revitalize chronically unhealed tissue.
The growing understanding of cellular biochemical processes has enabled technological advances in the treatment of complex wounds. Negative pressure wound therapy (NPWT) has been found to be a catalyst in secondary wound healing - a bridge between debridement and definitive closure. Multiple clinical studies indicate that applying subatmospheric pressure can optimize blood flow, decrease local tissue edema, remove excessive fluid and pro-inflammatory exudates, facilitate the removal of bacteria from the wound, and promote the moist environment required for proximate cells to heal more rapidly
A pioneer in this field, Dr. Pål Svedman, Professor of Medicine and noted plastic and reconstructive surgeon in Sweden, began developing NPWT technology with irrigation in the 1970s to improve wound care. In his research and clinical work, Dr. Svedman has continued to develop NPWT applications, including the ITI Wound Treatment System used in this study - the product of 30 years of proven clinical efficacy.
The U.S. Food and Drug Administration (FDA) measures improved wound healing outcomes as: the percentage of patients with complete wound closure; and time to complete healing or partial healing towards the facilitation of surgical wound closure.3 Based on our clinical series, NPWT with irrigation facilitated the tissue granulation process - improving wound healing for all enrolled patients and reducing time to closure.
The ITI Wound Treatment System
The ITI Wound Treatment System consists of an NPWT pump, porous open-cell polyurethane foam, a flexible semi-permeable polyurethane adhesive drape, an irrigation tube, and a suction tube - both tubes using adhesive SpeedConnect ports. The pump is designed for ease of use, delivering a controlled vacuum to the wound. A fluid collection canister is connected to the irrigation tube to isolate irrigation fluid passed through the dressing.
Methods
Ten patients were enrolled in a clinical series from April to October 2008, using the ITI Wound Treatment System with irrigation. Criteria for enrollment included a non-healing wound present for at least 4 weeks with post-debridement wound size greater then 1.0 cm2. Of the initial 11 patients screened for the clinical trial, 10 qualified for enrollment.
All enrolled patients exhibited lower extremity wounds that had previously failed traditional wound treatment - including alginate- based dressings, wound gels, and antibiotic creams. Nine patients had a relatively high percentage of necrotic tissue in the target wound area, ranging from 30% to 98%. (For two patients, data on initial percentage of necrotic tissue were not available.)
For each patient, NPWT was continuously applied, along with a new dressing change every other day or every third day. The irrigation feature of the ITI NPWT device was employed with each patient.
Results
The majority of patients (70%) healed within the 6-week period of the protocol timeframe - averaging 28 days time-to-heal. Overall, the average time to heal was 50 days.
Patients 5 and 6 required skin grafts, as well as ongoing NPWT treatment, to achieve healing. Patient 5 healed in 113 days. Patient 6 healed in 124 days. For both patients, their complications were not caused by the study device.
Patient 7 experienced a severe laceration in 3 toes of the study foot. This event was unrelated to the study ulcer site, which was unaffected by the laceration. The patient healed in 65 days under treatment.
Discussion
In this clinical series, the ITI Wound Treatment System promoted complete healing in the majority of patients in a satisfactory period of time. The device helped restore vitalized granulation tissue in multiple biologically bankrupt wounds that had initially presented with minimal to no granulation tissue.
Of particular note, the ITI Wound Treatment System foam dressings' pore size and strong adhesive properties support superior occlusion - enabling direct pressure (-70, -120, or -150 mmHg) to the wound. A two-port system provides, when prescribed, direct lavage of normal saline or lactated Ringer's solution into the wound - to be removed by the negative pressure gradient. By maintaining a moist wound environment, irrigation can decrease bioburden issues and biofilm development. Irrigation can also help diminish tissue ingrowth on foam dressings - reducing discomfort during dressing changes.
The ITI Wound Treatment System pump is lightweight and provides up to 18 hours of battery life. Its portability allows the mobile patient to receive continuous NPWT with irrigation.
Conclusion
The ITI Wound Treatment System is a safe and easily managed primary or secondary method to achieve chronic wound granulation and healing. It has been shown to decrease wound healing time.