Institute of Plastic Surgery, University of Padova, Padova, Italy.
J Plast Reconstr Aesthet Surg. 2012 Jan;65(1):91-9. doi: 10.1016/j.bjps.2011.08.016. Epub 2011 Aug 31.
Negative pressure wound therapy (NPT) has achieved widespread success in the treatment of difficult wounds. However, its effects are but partially explored, and investigations mostly concentrated at the wound-dressing interface; a detailed histological description of the evolution of wounds under NPT is still lacking.
Subsequent punch biopsies of NPT-treated chronic wounds of human patients were analysed. Phenomena occurring in wounds were quantified by analysis of proliferating cells nuclear antigen (PCNA) (proliferating nuclei), CD31 (blood vessels), CD68p (macrophages) and CD45 (lymphocytes) stained slides.
Three layers were identified in day-0 wounds. Over time, under NPT, the layers behaved differently: the most superficial (1.5 mm) developed granulation tissue, constant in thickness, with high proliferation index, increased in blood vessels density and developed acute inflammation. Instead, the two deeper layers decreased in proliferation rate, maintained vessels density unchanged, were cleared of chronic inflammation and oedema and underwent progression towards stable tissue.
Indeed, while most research has focused on induction of superficial granulation tissue by NPT, deeper layers appear to be also affected, with relieving of chronic inflammation and tissue stabilisation. This may be an important and under-appreciated effect, playing a role in the known positive outcomes of NPT, such as better graft-taking rates.
负压伤口治疗（NPT）在治疗困难伤口方面取得了广泛的成功。然而，其效果尚未得到充分探索，研究大多集中在伤口敷料界面；缺乏对 NPT 下伤口演变的详细组织学描述。
对接受 NPT 治疗的慢性人类患者的伤口进行后续冲孔活检。通过分析增殖细胞核抗原（PCNA）（增殖核）、CD31（血管）、CD68p（巨噬细胞）和 CD45（淋巴细胞）染色切片来量化伤口中发生的现象。
在第 0 天的伤口中识别出了 3 个层。随着时间的推移，在 NPT 下，这些层的表现不同：最浅层（1.5 毫米）形成肉芽组织，厚度恒定，增殖指数高，血管密度增加，并发生急性炎症。相比之下，两个更深的层增殖速度降低，保持血管密度不变，清除慢性炎症和水肿，并向稳定组织进展。
事实上，尽管大多数研究都集中在 NPT 诱导浅层肉芽组织上，但深层组织似乎也受到影响，慢性炎症得到缓解，组织稳定。这可能是一个重要且被低估的影响，在 NPT 的已知积极结果中发挥作用，例如提高移植物成活率。
