Smoking is a recognized risk factor for healing complications after surgery, but the pathophysiological mechanisms remain largely unknown.
Dr Lars Tue Sørensen clarified how smoking and nicotine affects wound healing processes and to establish if smoking cessation and nicotine replacement therapy reverse the mechanisms involved.
Pathophysiological studies addressing smoking and wound healing were identified through electronic databases (PubMed, EMBASE) and by hand-search of articles' bibliography.
Of the 1460 citations identified, 325 articles were retained following title and abstract reviews.
|Nicotine appears to stimulate proliferation|
|Annals of Surgery|
In total, the researcher included and systematically reviewed in 177 articles.
Smoking decreases tissue oxygenation and aerobe metabolism temporarily.
The inflammatory healing response is attenuated by a reduced inflammatory cell chemotactic responsiveness, migratory function, and oxidative bactericidal mechanisms.
In addition, the researcher found that the release of proteolytic enzymes and inhibitors is imbalanced.
The researcher noted that the proliferative response is impaired by a reduced fibroblast migration and proliferation in addition to a downregulated collagen synthesis and deposition.
Smoking cessation restores tissue oxygenation and metabolism rapidly.
Inflammatory cell response is reversed in part within 4 weeks, whereas the proliferative response remains impaired.
The researcher observed that nicotine does not affect tissue microenvironment, but appears to impair inflammation and stimulate proliferation.
Dr Sørensen commented, "Smoking has a transient effect on the tissue microenvironment and a prolonged effect on inflammatory and reparative cell functions leading to delayed healing and complications."
"Smoking cessation restores the tissue microenvironment rapidly and the inflammatory cellular functions within 4 weeks, but the proliferative response remain impaired."
"Nicotine and nicotine replacement drugs seem to attenuate inflammation and enhance proliferation but the effect appears to be marginal."