2017-18 HSC Section 4 Green Book

HY P E R TROP H I C S CAR S AND K E LO I D S

Corticosteroid injection is often considered to be the fi rst choice for intralesional treatment of pathological scars. It suppresses the in fl ammatory process in the wound and reduces collagen and glycosaminoglycan synthesis. Furthermore, it has an inhibiting effect on fi broblast growth and it enhances collagen and fi broblast degen- eration. Corticosteroid injection is believed to be a good combination between effective treatment, cost effec- tiveness, and minimal burden for the patient. 20 – 23 Intralesional verapamil, a calcium channel blocker, was fi rst introduced in 1994 by Lee and colleagues 24 to treat burn scars. Calcium antagonists seem to work by reducing collagen production and inducing collage- nase synthesis. They may be a reasonable and safe alternative to corticosteroid injection for the treatment of hypertrophic scars and keloids. 15,25 The literature on this subject is relatively sparse andmany studies are limited by small patient cohorts. Given these limitations within the literature, it has been dif fi cult to make evidence-baseddecisionsweighing the potential side effects against the bene fi ts of treatment with a calcium channel blocker. The aim of this systematic reviewwas to provide a comprehensive overview of mechanism of action, ef fi cacy, and possible adverse events of calcium antagonists in pathological scars. This review was designed according to the principles outlined in the Preferred Items for Systematic Reviews andMeta-Analysis. 26 A literature searchwas performed of the Cochrane Library and using PubMed to query the MEDLINE database through November 1, 2014. Search terms included ( “ keloids ” OR “ keloid scars ” OR “ hypertrophic scars ” ) AND ( “ verapamil ” OR “ calcium antagonist ” OR “ calcium channel blocker ” ). Refer- ences were also screened for additional relevant articles. Abstract reviews were performed for all articles to identify appropriate articles for full-text review. For articles showing insuf fi cient data in the title and abstract, a full article review was performed to make a good decision regarding inclusion. Inclusion criteria required articles to assess mechanism of action of a cal- Methods Literature Search

cium antagonist in scars. Randomized controlled trials, clinical trials, and case reports that assessed the ef fi cacy of a calcium antagonist in scars were also included. Articles in languages other than English were excluded. No limits were applied for year of publication or pub- lication status. After abstract reviews and full-text evaluation, 14 articles were yielded appropriate for analysis. An overview of the literature search and selection is outlined in Figure 1. Articles were classi fi ed into two categories, either focusing on mode of action or focusing on ef fi cacy and adverse events of calcium antagonists. Study charac- teristics and outcomes were determined. The study characteristics extracted for the fi rst category included lead author, publication year, and type of study. Outcome was de fi ned as a description of results on mechanism of action. The study characteristics extracted for the second category included lead author, publication year, type of study, study size, patient characteristics, intervention, comparison arm, out- come, and follow-up period. Outcomes in the second category were de fi ned as ef fi cacy and adverse events. Available evidence in this category was assessed and synthesized, with emphasis on the highest level of study available. Levels of evidence were assessed according to criteria published by the Oxford Centre of Evidence- Based Medicine Levels of Evidence. 27 A search of the Cochrane Library and MEDLINE databases identi fi ed 23 unique articles that were eli- gible for screening, of these 12 were rejected after their titles and abstracts were reviewed. Three more articles were identi fi ed from references and citations of review articles. The 14 articles that were included were clas- si fi ed into two categories: category one comprised six articles (mechanism of action) and category two comprised eight articles (ef fi cacy and adverse events). All articles that were included in the fi rst category were in vitro studies, performed with cells studied outside their normal biological context. 28 – 33 The articles that Results Study Characteristics Data Extraction

DE RMATOLOG I C S URG E RY

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