The authors previously described induction of spontaneous tissue generation by implanting a collagen matrix and a ligated pedicle (arteriovenous bundle) into a hollow porous chamber in vivo in the rabbit. They hypothesized that increased tissue volume could be obtained by the application of basic fibroblast growth factor (bFGF) and/or by increasing the chamber size and porosity.
In rabbits, a saphenous arteriovenous pedicle and a collagen sponge were inserted into a porous chamber in the groin. Small-volume pore chambers (experiment 1, n = 7) and larger-volume, wider pore chambers (experiment 2, n = 13) were compared, and each was compared with and without bFGF. An additional three flaps of experiment 2 with bFGF were skin grafted, microsurgically transplanted to the ear, and evaluated at 6 months for stability.
All patent chambers grew tissue; chambers with bFGF were almost filled, and those without were only half-filled. Histomorphometric analysis confirmed a significant difference. The larger-volume, larger-pore chambers produced more than twice the volume of tissue as the smaller chambers did, and this was significant. Tissue volume in both the control and bFGF groups of experiment 2 was significantly greater than that in the respective groups of experiment 1. Histology, angiography, and scanning electron microscopy confirmed greater vascularity in the bFGF groups and demonstrated vascular connections penetrating the chamber pores linking with angiogenic sprouts, probably from the vasa vasorum of the pedicle, to contribute to new growth. Transplanted flaps survived and appeared normal 6 months later.
Patent pedicles, bFGF, large pore size, and larger-volume chambers all seemed to contribute to increased tissue growth in this model. The tissue is stable long term.
Kobe, Osaka, and Tokyo, Japan; and Melbourne, Australia
From the Division of Plastic and Reconstructive Surgery, Shinko Hospital; Department of Plastic and Reconstructive Surgery and Department of Laboratory Medicine, Division of Surgical Pathology, Osaka Medical College; Fine Structure Analysis Section, Mitsubishi Kagaku Institute of Life Science; and Bernard O’Brien Institute of Microsurgery and Department of Surgery, St. Vincent’s Hospital, Melbourne University.
Received for publication August 26, 2004; revised June 20, 2005.
Presented in part and awarded first prize in poster session at the Inaugural Congress of the World Society for Reconstructive Microsurgery, in Taipei, Taiwan, October 29 to November 3, 2001.
Yoshio Tanaka, M.D., Division of Plastic and Reconstructive Surgery, Shinko Hospital, 1-4-47 Wakihamacho, Chuoku, Kobe, Japan 651-0072, firstname.lastname@example.org