A new model for chronic in vivo analysis of the periosteal microcirculation

Microvascular perfusion is indispensable for the growth and remodulation of membrane bone. Trauma, inflammation and surgical interventions may alter periosteal perfusion. However, there is not much known about periosteal perfusion in membrane bones. Therefore, the aim of this study was to establish a new chronic model that permits the repeated in vivo analysis of the microcirculation of periosteum.

A circular skin island with a diameter of 6 mm was excised at the forehead of six Lewis rats. Then a newly developed chamber was implanted, containing a coverglass to protect the periosteum. Intravital microscopy (IVM) enables a quantitative analysis of periosteal microcirculation immediately as well as 3, 5 and 10 days after chamber implantation. At the end of the experiment the calvaria and periosteum were removed for histological examination. Six unoperated Lewis rats served as histological controls.

The periosteal microcirculation remained stable over 10 days. The implantation of the chamber did not result in any substantial inflammatory response. The functional microvascular density was 131.2+/-19.3 cm/cm(2). The histological examinations revealed a regular anatomical structure of periosteum and bone including an intact interface.

The presented model allows for the first time to conduct a repetitive, quantitative in vivo analysis of the periosteal microcirculation in membrane bone. Future studies may thus evaluate novel strategies to influence the periosteal perfusion.