Histological studies on granulation tissue from bipedicle tube flaps

Histological studies were performed on granulation tissue from cylinders implanted 2 to 8 weeks and 4 months in bipedicle tube flaps on rabbits. Tissue from cylinders implanted in skin folds were used as controls. Flap and control tissue showed similar changes over the weeks. At weeks 2 and 3 the tissue was rich in cells, blood vessels and collagenous fibres. At week 4 the tissue showed transitional changes to week 5, when there were zones of loosely textured tissue with fine, fragmented collagen fibres. At week 5 some of the loose tissue was replaced by fat. Macrophages and inflammatory cells had appeared. By week 7 the fatty and collagenous tissue was mature and macrophages and inflammatory cells had disappeared.