C. N. Thompson2,3, R. Smith4, B. Carney4,5,7, K. Monger4, L. Moffatt2,4,5,8, J. W. Shupp2,4,5,6, L. S. Johnson2,4,6 4Firefighters’ Burn and Surgical Research Laboratory,MedStar Health Research Institute,Washington, DC, USA 5Georgetown University School of Medicine,Department Of Biochemisty,Washington, DC, USA 6Georgetown University School of Medicine,Department Of Surgery,Washington, DC, USA 7Georgetown University School of Medicine,Biochemistry, Graduate Student,Washington, DC, USA 8Georgetown University School of Medicine,Biochemistry, Faculty Appointment,Washington, DC, USA 2MedStar Washington Hospital Center,The Burn Center,Washington, DC, USA 3Georgetown University Medical Center,General Surgery,Washington, DC, USA
Introduction: Negative pressure wound therapy (NPWT) is used to accelerate healing of various wounds. Studies have demonstrated that NPWT optimizes blood flow, decreases local tissue edema, and removes excess fluid from the wound bed. Use of circumferential NPWT on distal extremities is controversial; while isolated case reports suggest positive outcomes, macrodeformation of the tissue in the wound bed has been shown to increase extracellular pressure. This data has been extrapolated to suggest a risk for decreased blood flow in the setting of circumferential placement. In the present experiment, the impact of circumferential NPWT on perfusion was examined in hands.
Methods: Part 1: Healthy volunteers (n=16) had NPWT sponge placed circumferentially around a hand and secured into position in the standard fashion. Windows for imaging the tissue during the therapy application were created over the thenar eminence (palmar area) and over the central dorsal hand (dorsal area) and 125mmHg suction was applied for 15min. Laser doppler imaging (LDI) was utilized to measure the perfusion of the hands before (baseline), during, and after NPWT. Regions of interest were selected for analysis in each area and averaged to obtain mean perfusion units. Data were analyzed using a one-way ANOVA to determine the significance of the differences in perfusion between pre-and post-application of NPWT and between regions of the hand imaged. Part 2: A retrospective case review was performed on patients who underwent split thickness skin grafting and NPWT to identify graft loss, need for repeat operation, and pain associated with therapy.
Results:
Part 1:There was no difference in perfusion during and after NPWT placement compared to baseline in the palmar position (Figure 1, p=.86). A statistically significant increase in perfusion at the end of NPWT compared to baseline was identified in the dorsal position (p=0.01).
Part 2:Over a twelve-month time period, 63 patients underwent burn eschar excision, split thickness skin grafting and the placement of circumferential NPWT. Only 1 patient required a repeat operation for graft loss; two additional patients had documented graft loss requiring local wound therapy. No patients deviated from protocolized unit pain algorithms for reasons related to their NPWT.
Conclusion: The use of circumferential NPWT on the hand does not decrease cutaneous blood flow during the therapy period. Split thickness skin grafts stabilized with NPWD rarely need second operations for graft failure and are tolerated by patients for the 72-hour period of treatment. Maintenance of blood flow coupled with other therapeutic properties of NPWT may explain upper extremity skin grafting results after use of NPWT for stabilization.
