Histological evolution of chronic wounds under negative pressure therapy

• Published in: Journal of plastic, reconstructive & aesthetic surgery Vol. 65; no. 1; pp. 91 - 99
• Main Authors: Bassetto, Franco, Lancerotto, Luca, Salmaso, Roberto, Pandis, Laura, Pajardi, Giorgio, Schiavon, Mauro, Tiengo, Cesare, Vindigni, Vincenzo
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2012; Elsevier
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Biopsy, Needle; Chronic Disease; Female; Follow-Up Studies; Granulation Tissue - pathology; Humans; Immunohistochemistry; Leg Ulcer - pathology; Leg Ulcer - physiopathology; Leg Ulcer - therapy; Male; Medical sciences; Middle Aged; Negative pressure therapy; Negative-Pressure Wound Therapy - methods; Plastic Surgery; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Time Factors; Treatment Outcome; Ulcer; VAC Therapy; Vacuum; Wound; Wound Healing - physiology; VAC Therapy; Ulcer; Vacuum; Wound; Negative pressure therapy; Chronic; Treatment; Surgery; therapy; Open cell foam; Evolution; Negative pressure
• ISSN: 1748-6815; 1878-0539
• DOI: 10.1016/j.bjps.2011.08.016

Summary Background 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. Materials and Methods 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. Results 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. Discussion 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.