Swiss Prospective Autologous Bone Flap Resorption Study

The complications after reimplantation of cryoconserved autologous bone flaps are reported inhomogeniously in the literature. Especially the incidence of bone flap resorption varies from 0% to about 30%. More recent retrospective studies seem to find higher resorption rates and thus suggest to implant artificial bone replacements from the start. The Swiss Prospective Autologous bone Resorption Study is the first propspective observational study designed to determine the true incidence of autologous bone resorption.

Patients undergoing decompressive craniectomy and delayed reimplantation of the cryoconserved autologous bone flap are included in a clinical and image-based follow-up to identify cases and severity of bone flap resorption. The explanted autologous bone flaps are cryoconserved and reimplanted at a time-point defined by the surgeon according to standards of the participating hospital. The fixation of the bone flap is also performed according to the surgeon's decision. A cranial CT is performed within one week after reimplantation to define a baseline. A second, only clinical, follow-up will take place within 2 months after reimplantation. Two more follow-ups including photodocumentation of the cranial and facial symmetry (portrait and profile) and cranial CT will take place 12 and 24 months after reimplantation. The indication for surgical revision in case of bone flap resorption is independent from the study and falls under the responsibility of the treating surgeon.