Department of Reconstructive and Aesthetic Plastic Surgery, University of Turin, San Giovanni Battista Hospital, Turin, Italy.
Int Wound J. 2011 Aug;8(4):355-64. doi: 10.1111/j.1742-481X.2011.00798.x. Epub 2011 May 12.
Negative pressure wound therapy (NPWT) is becoming routine for the preparation of wounds prior to grafting for wound closure. We have been using both foam- and gauze-based NPWT to prepare wounds for closure prior to skin grafting and have obtained similar proportions of closed wounds; 7/7 for wounds treated with gauze-based NPWT and 11/11 for wounds treated with foam-based NPWT. In our follow-up consultations we observed that skin grafts on the foam-treated patients were less pliable than those on the gauze-treated patients. To assess what the mechanism of this effect might be, we compared the specific details of the treatments of both 11 foam and 7 gauze patients, including depth, location, patients' age and co-morbidity; biopsies of granulation and scar tissue were taken and stained with haematoxylin-eosin and by Masson's trichrome staining and conducted ultrasound analysis of the closed wounds, to see if there were features which explained those effects. All foam patients were treated at -125 mm Hg for an average of 25·9 days before skin grafts were applied. All gauze patients were treated at -80 mm Hg for an average of 24·7 days before skin grafts were applied. Biopsies of granulation tissue prior to skin grafting from five foam and four gauze-based NPWT patients did not reveal any obvious histological differences between the treatments. Ultrasound analysis of the skin-grafted wounds showed an average depth of scar tissue of 18 mm in the wound beds of the foam-treated wounds and 7 mm in the gauze-treated ones. Biopsies taken on the scar tissue after treatment with the gauze showed a minor tissue thickness and disorganisation and less sclerotic components. The findings of this preliminary analysis suggest that foam-based NPWT may induce a thicker layer of scar tissue beneath skin grafts than gauze-based NPWT which might explain a reduced pliability of the reconstructed bed. At present it is unclear which mechanism might be responsible for the difference in pressure (-125 versus -80 mm Hg), either the length of the time taken to reconstruct the wound bed or the intrinsic nature of the foam or gauze on the tissue surface. Prospective studies are necessary to investigate whether these preliminary observations are confirmed and to investigate what the mechanism might be.
负压伤口治疗（NPWT）在准备植皮以闭合伤口方面正变得常规化。我们一直在使用泡沫和纱布基 NPWT 来准备植皮前的伤口，并且获得了相似比例的闭合伤口；用纱布基 NPWT 治疗的 7/7 例伤口和用泡沫基 NPWT 治疗的 11/11 例伤口均闭合。在我们的随访咨询中，我们观察到泡沫处理的患者的皮肤移植物不如纱布处理的患者柔软。为了评估这种效果的机制，我们比较了 11 例泡沫和 7 例纱布患者的治疗细节，包括深度、位置、患者年龄和合并症；对肉芽组织和瘢痕组织进行活检，并进行苏木精-伊红染色和马松三色染色，对闭合伤口进行超声分析，以观察是否存在可以解释这些影响的特征。所有泡沫患者在应用皮肤移植物前均以 -125mmHg 的负压治疗，平均治疗 25.9 天。所有纱布患者在应用皮肤移植物前均以 -80mmHg 的负压治疗，平均治疗 24.7 天。在应用皮肤移植物之前，从五例泡沫和四例纱布基 NPWT 患者的肉芽组织活检中，两种治疗方法之间没有发现任何明显的组织学差异。对皮肤移植物伤口的超声分析显示，泡沫处理伤口的疤痕组织深度平均为 18mm，而纱布处理伤口的疤痕组织深度为 7mm。纱布处理后的疤痕组织活检显示，组织厚度较小、组织紊乱和较少的硬化成分。这项初步分析的结果表明，与纱布基 NPWT 相比，泡沫基 NPWT 可能在皮肤移植物下诱导更厚的疤痕组织层，这可能解释了重建床的柔韧性降低。目前尚不清楚哪种机制可能导致压力（-125 与-80mmHg）的差异，是重建伤口床所需的时间长短，还是组织表面的泡沫或纱布的固有性质。需要进行前瞻性研究来调查这些初步观察结果是否得到证实，并研究可能的机制。
