Comparison of Two Methods of Securing Skin Grafts Using Negative Pressure Wound Therapy: Vacuum Assisted Closure (VAC) and Gauze Suction (GSUC)
This trial is active, not recruiting.
|Sponsor||University of Chicago|
|Start date||May 2009|
|End date||December 2011|
|Trial size||156 participants|
|Trial identifier||NCT00952120, 16863B|
The purpose of this study is to compare how well two methods (VAC and G-SUC) of securing skin grafts using negative pressure wound therapy work. Negative pressure wound therapy is a commonly used method of applying suction on wounds to remove fluid from wound and to promote healing. The VAC system is widely used and consists of a foam dressing and a portable computerized suction pump. The G-SUC method uses commonly available dressing supplies attached to vacuum (suction) pump located on the wall above a hospital bed. The investigators have frequently used both methods over the past 10 years and have not observed any specific negative side effects of either.
|Endpoint classification||bio-equivalence study|
|Intervention model||parallel assignment|
|Masking||double blind (subject, caregiver, investigator, outcomes assessor)|
Data for Primary Outcomes: (intended to establish that G-SUC is not inferior to VAC) 1. Percentage take in meshed grafts and sheet grafts 2. Skin graft size
time frame: 2 years
Data for Secondary Outcomes: (intended to establish G-SUC is cheaper, and can be used in wounds where VAC cannot) 1. Failure to maintain dressing because of fluid or suction leaks 2. Time spent on dressing changes 3. Cost of supplies and rental
time frame: 2 years
Male or female participants at least 18 years old.
Inclusion Criteria: - Adult patients of any sex, hospitalized at the University of Chicago Medical Center, requiring split thickness skin autografts with wounds that are amenable to placement of an occlusive dressing for negative pressure therapy will be eligible to participate in the study Exclusion Criteria: - Pregnant women, children under 18 years of age and other patients who are "vulnerable" as defined by the Institutional Review Board will not be eligible for the study
|Official title||Comparison of Two Methods of Securing Skin Grafts Using Negative Pressure Wound Therapy: VAC and GSUC|
|Principal investigator||Lawrence J Gottlieb, MD|
|Description||STUDY DESIGN: A prospective, randomized study will be conducted in approximately 156 subjects. The investigators expect the duration of data collection to be 2 years. 1. PATIENT SELECTION Adult patients of any sex, hospitalized at the University of Chicago Medical Center, requiring split thickness skin autografts with wounds that are amenable to placement of an occlusive dressing for negative pressure therapy will be eligible to participate in the study. If both the patient and the primary treating surgeon agree to participate, they will receive informed consent. Pregnant women, children under 18 years of age and other patients who are "vulnerable" as defined by the Institutional Review Board will not be eligible for the study. 2. STUDY PROCEDURE Preoperative Procedures: Patients with wounds requiring skin grafting will enter the trial upon consent of the patient and the preoperative decision by the surgeon to secure the skin graft with negative pressure therapy. Upon entry, the primary physical therapist will be immediately informed of a study participant and will place either the G-SUC or VAC dressing at the conclusion of the operation. The randomization scheme will be prepared by the study statistician using computer generated random numbers The surgeon will be blinded to the treatment modality until the primary physical therapist places the randomized therapy. Intraoperative Procedures: Wounds will undergo debridement using standard techniques to a healthy, viable wound bed. Split thickness skin grafts harvested from the patient will be obtained between 0.008-0.010 inches using an electric dermatome. In addition to standard methods of achieving hemostasis, Tisseel (Baxter, Deerfield, IL) will be used as an adjunct for the preparation of the wound bed. All grafts will be secured with N-Terface Interpositional Material (Winfield Laboratories, Richardson, TX) and a single layer of Acticoat (Smith and Nephew, Quebec, Canada). Patients with skin grafts undergoing VAC therapy will be managed with continuous negative pressure delivered by the computerized VAC suction unit at 75-125 mm Hg. The suction will be applied to a standard open cell VAC foam dressing supplied by KCI, Inc and sealed with an occlusive cover. Patients with skin grafts undergoing G-SUC therapy will be managed with negative pressure delivered by low continuous wall suction at 75-80 mm Hg. The suction will be applied to standard gauze dressing and sealed with an occlusive cover. Postoperative Procedures: Patients on either therapy will remain on continuous negative pressure therapy from the conclusion of their surgery until dressing takedown. Patients undergoing VAC therapy will be transported with the computerized VAC suction unit. Maintenance of negative pressure during transport of patients undergoing G-SUC therapy will be accomplished by clamping the connection tubing with hemostats prior to disconnection to wall suction units. All dressings will be discontinued on post operative day #4 or 5 and graft take will be assessed with two methods in the following manner: 1. Areas of non-take will be clearly marked with a pen by a researcher blinded to the treatment modality 2. Images of the graft with a ruler for scale will be taken by a digital camera 3. The entire graft area will be determined in pixels 4. The areas of non-take will be determined in pixels 5. The percentage of non-take will then be calculated 6. The areas will also be measured and recorded Data analysis from the images will be conducted by a researcher blinded to the treatment modality. Wound size will also be calculated as per Xakellis & Frantz method (1997): wound surface area = length x width x 0.783. If a G-SUC or VAC dressing cannot be maintained because of either persistent fluid or suction leaks, the attending physical therapist will attempt to reinforce the dressing. If after 2 attempts per 24-hour period, the dressing still cannot be maintained, that patient will be considered to have failed negative pressure wound therapy. Patients who fall into this category will be able to crossover into the other treatment arm, but additional data regarding their treatment will not considered in the results of the study. The cost of VAC rental, supplies and time performing dressing changes will be recorded for the duration of negative pressure wound therapy for each patient. The attending physical therapist will collect and maintain the database. Wound Specific Procedures: Upper Extremity. All skin grafts on mobile structures, such as those crossing joints or directly on muscle, will be splinted to prevent shear. Otherwise, patients will be allowed to move about ad lib. Lower Extremity. All skin grafts on mobile structures, such as those crossing joints or directly on muscle, will be splinted to prevent shear. Patients will remain on bedrest with leg elevation to prevent lower extremity edema until negative pressure therapy is discontinued. Chest, Abdomen, Back, Head, Neck. Mobility will be allowed ad lib. Perineum. Patients will remain on bedrest until discontinuation of negative pressure therapy to prevent shear. 3. SUMMARY OF DATA TO BE COLLECTED Data for Primary Outcomes: (intended to establish that G-SUC is not inferior to VAC) 1. Percentage take in meshed grafts and sheet grafts 2. Skin graft size Data for Secondary Outcomes: (intended to establish G-SUC is cheaper, and can be used in wounds where VAC cannot) 1. Failure to maintain dressing because of fluid or suction leaks 2. Time spent on dressing changes 3. Cost of supplies and rental Ancillary Data: (intended to establish that there is no bias in the groups and other areas of interest) 1. Age, sex, etiology of wound, location of wound, co-morbid factors including diabetes, renal failure, immunosuppression, prior radiation, peripheral vascular disease, malnutrition 2. Wound photographs 3. Specific bacteriology of tissue cultures 4. Presence of healed wound at the time of discharge 5. Length of inpatient stay 6. Operations for wound debridement, soft tissue reconstruction, or other indications 4. STUDY RECORDS Completed case report forms will be confidential and kept in a secured file by the principal investigator. 5. RISKS & BENEFITS TO PATIENTS The investigators are not aware that there are specific risks associated with negative pressure wound therapy, and the technique has not been associated with specific adverse outcomes at our hospital or in the published literature. Negative pressure wound therapy allows for more rapid and reliable wound healing for many patients. Data from this study may help us to expand the indications for negative pressure wound therapy. 6. STATISTICS Sample size is calculated on the basis of the primary endpoint defined as the non-take percentage on day 4/5. Using a non-inferiority testing strategy with α = 0.05 and a non-inferiority margin of 5%, 156 subjects in total (78 in each group) are required to achieve 80% statistical power. This calculation assumed a common within-group standard deviation of 12.5% (estimated based on the non-take percentage being normally-distributed with a range of 0% to 50%). The randomization scheme will be prepared by the study statistician using computer-generated random numbers. Demographics, baseline variables, and adverse events will be summarized with descriptive statistics, including mean, median, or proportion, as appropriate. The rate of failure to maintain dressing will be compared between the two groups using Fisher's exact test. The non-take percentage on post-op day 4/5, total cost of supplies and rental, and the time spent on dressing changes will be compared between groups using two-sample t tests with the log or square root transformation used if there is evidence of non-normality. 7. TERMINATION OF STUDY The study will be terminated after successfully completing 156 study patients, unless administrative or medical problems necessitate early termination or if one NPWT system demonstrates exceptional performance compared with the other. However, the determination of "exceptional performance" will likely require statistical analyses which will occur halfway through the study. After half of the required number of subjects have been enrolled, comparison of the percentage take of the grafts in the two treatment arms will be performed. Early termination of the study due to evidence of a treatment difference will be considered if the difference between the groups is significant at the 0.003 level. This criterion was chosen based on the methods of Lan and DeMets for maintaining the overall two-sided alpha level at 0.05. If the study is terminated early, a full explanation will be provided to the IRB. 8. PAYMENT TO SUBJECTS There will be no payment to the subjects|
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