Livingstone John P, Singh Dylan, Murray Patrick C
Orthopedic Surgery, Queen's Medical Center, Honolulu, USA.
John A. Burns School of Medicine, University of Hawaii, Honolulu, USA.
Cureus. 2021 Apr 9;13(4):e14389. doi: 10.7759/cureus.14389.
Background Negative pressure wound therapy (NPWT) and closed incisional negative pressure wound therapy (ciNPWT) have been shown to promote the healing of acute and chronic wounds. Despite the growth in their usage, the mechanism by which they promote healing is not fully understood. Several studies have shown that NPWT results in a combination of microdeformation and macrodeformation, which may promote wound recovery. The macrodeformation forces have raised concerns about circumferential NPWT compressing the extremity and decreasing perfusion distal to the NPWT. The literature on circumferential NPWT is mixed, with some studies showing increased perfusion, while others have shown decreased perfusion. We hypothesized that a near-circumferential ciNPWT dressing applied over intact skin would provide a "lift-off" force rather than a compressive force. We also theorized that as the sponge contracts under negative pressure while in a near-circumferential setting, the dressing will pull on the surrounding skin and tissue, leading to a decrease in the pressure of the extremity. This could potentially translate to improved venous and lymphatic return, increasing perfusion to the tissue beneath the sponge as well as distal to the sponge. Methods This study consisted of three separate experiments. The first experiment measured the width and length of a ciNPWT dressing at various negative pressures. The second experiment utilized an in vitro model consisting of an elastic ball and tubing to examine the effects that circumferential and near-circumferential ciNPWT dressings may have on extremity pressure. Varying lengths of ciNPWT dressings were applied to the ball, ranging from 25% circumferential to 100% circumferential. The pressure within the ball was monitored as varying lengths of circumferential dressings were applied at various negative pressures. The third experiment utilized the same model as the second experiment but with a 66% circumferential dressing and various baseline ball pressures to see how extremity pressure may impact the ability of the ciNPWT dressing to alter extremity pressure. Results The first experiment demonstrated that a ciNPWT dressing decreased in length and width in a linear fashion as negative pressure was applied. The second experiment revealed that both fully circumferential and near-circumferential dressings resulted in a decrease in the pressure of the elastic ball at lower levels of suction. The greatest decrease in ball pressure was noted with the 66% near-circumferential dressing. With greater suction, however, the pressure within the ball was noted to increase above baseline. The third experiment illustrated that as the baseline pressure of a ball was increased, the dressing had less of an ability to change the pressure of the ball. Conclusions These results suggest that near-circumferential and circumferential ciNPWT systems may decrease the pressure of an extremity at certain negative pressures and that compression may be less likely to occur when used on a higher-pressure extremity.
背景 负压伤口治疗（NPWT）和封闭式切口负压伤口治疗（ciNPWT）已被证明可促进急慢性伤口的愈合。尽管其使用量不断增加，但其促进愈合的机制尚未完全明确。多项研究表明，NPWT会导致微观变形和宏观变形，这可能促进伤口恢复。宏观变形力引发了人们对环形NPWT压迫肢体并减少NPWT远端灌注的担忧。关于环形NPWT的文献结论不一，一些研究显示灌注增加，而另一些研究则显示灌注减少。我们推测，在完整皮肤上应用近环形ciNPWT敷料会产生“提起”力而非压缩力。我们还推测，当海绵在负压下处于近环形状态时收缩，敷料会拉动周围的皮肤和组织，导致肢体压力降低。这可能会改善静脉和淋巴回流，增加海绵下方以及海绵远端组织的灌注。方法 本研究包括三个独立实验。第一个实验测量了ciNPWT敷料在不同负压下的宽度和长度。第二个实验使用了一个由弹性球和管道组成的体外模型，以研究环形和近环形ciNPWT敷料对肢体压力的影响。将不同长度的ciNPWT敷料应用于球上，范围从圆周的25%到100%。在不同负压下应用不同长度的环形敷料时，监测球内压力。第三个实验使用了与第二个实验相同的模型，但使用了66%圆周的敷料和各种基线球压力，以观察肢体压力如何影响ciNPWT敷料改变肢体压力的能力。结果 第一个实验表明，随着负压的施加，ciNPWT敷料的长度和宽度呈线性减小。第二个实验表明，在较低吸力水平下，全圆周和近圆周敷料均导致弹性球压力降低。66%近圆周敷料使球压力下降最大。然而，随着吸力增加，球内压力高于基线水平。第三个实验表明，随着球的基线压力增加，敷料改变球压力的能力减弱。结论 这些结果表明，近圆周和圆周ciNPWT系统在特定负压下可能会降低肢体压力，并且在较高压力的肢体上使用时，发生压迫的可能性较小。
