Histological evaluation of local verapamil hydrochloride injection in the prevention of keloid recurrence after excision

ABSTRACT

Keloids occur as the result of an exaggerated wound healing of skin following various types of injury. In addition to presenting a cosmetic concern, they are extremely difficult to treat. The aim of the present work was to assess histologically the efficacy of verapamil hydrochloride [a calcium channel blocker] local injection on prevention of recurrence of surgically excised keloid. 40 keloid subjects divided into two equal groups Group I; subjected to only surgical excision of their keloids. Group II; subjected to intradermal verapamil injection for 2 months after surgical excision of keloid. Skin biopsies from the healed wound of both experimental groups were taken after 3 months [subgroups Ib, IIb] and 6 months [subgroups Ib, IIb] postoperatively. Tissue specimens were also collected from the excised keloids. Informed consents were taken from subjects of both groups including all steps of the study. The obtained specimens were further processed for light microscopic study by haematoxylin and eosin [H and E] and trichrome stains. Semithin sections and electron microscopic examination were also done. Examination of the healed skin after keloid surgical excision [group Ia. Ib], showed prominent neutrophils and mast cells. Large spindle- shaped fibroblasts with dilated cisternae of endoplasmic reticulum were frequently encountered among coarse collagen bundles denoting accelerated rate of collagen production. This appearance may point to local histological recurrence of keloid. On the other hand, verapamil- injected skin after keloid excision [verapamil- injected group IIa, IIb] revealed little collagen in the dermal interstitium forming thin dispersed fibrils. Ultrastructuraly, the dermal fibroblasts of this group exhibited oval to rounded outlines and showed few narrow cisternae of endoplasmic reticulum. The verapamil- induced cell rounding is related to the calcium- dependent change in the cytoskeleton of fibroblasts. This appearance is associated with decreased synthesis and secretion of the extracellular matrix. Verapamil injection provided a satisfactory tool for prevention of recurrence of surgically excised keloid