Swiss Prospective Autologous Bone Flap Resorption Study

Terminated

Brief Summary: 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.

Detailed Description: 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.

Recruitment & Eligibility

Inclusion Criteria

all patients after hemicraniectomy or bifrontal craniectomy
age 18-99 y/o
ability to understand and sign informed consent (alternatively, legal representative may sign)

Exclusion Criteria

Arm && Interventions

Group	Intervention	Description
Reimplantation of cryoconserved bone flap	Reimplantation of cryoconserved bone flap	All patients who receive reimplantation of a cryoconserved autologous bone flap

Primary Outcome Measures

Name	Time	Method
Incidence of a relevant bone resorption within 12 months after reimplantation	12 months	The extent of bone flap resorption is analyzed as well objectivela as subjectivels: objective criteria: Volumetric reconstruction of the bone flap from the CT scans and subtration of the actual bone flap volume from the 3D model at the basline-timepoint directly after reimplantation subjective: a bone flap resorption score is validated

Secondary Outcome Measures

Name	Time	Method
Fluid collections and bleedings	2, 12 and 24 months after reimplantation	subgaleal, epidural and subdural fluid collections and hematomas
Incidence of an indication for surgical revision	12 and 24 months after reimplantation	The indication for a surgical revision falls under responsibility of the treating surgeon.
Death	2, 12 and 24 months after reimplantation	death
timepoint between explantation and reimplantation	2, 12 and 24 months after reimplantation	measured in months
fragmentation of the bone flap	2, 12 and 24 months after reimplantation	in number of pieces
pathologies leading to explantation of the bone flap (hemicraniectomy)	2, 12 and 24 months after reimplantation	trauma, tumor, stroke and others
Infections	2, 12 and 24 months after reimplantation	Infections
Hydrocephalus	2, 12 and 24 months after reimplantation	hydrocephalus
patient age	2, 12 and 24 months after reimplantation	in years
Temporal muscle atrophy	2, 12 and 24 months after reimplantation	temporal muscle atrophy
temperature used for cryoconservation	2, 12 and 24 months after reimplantation	in °C

Locations (2): Inselspital Bern
🇨🇭
Bern, Switzerland
Dept. of Neurosurgery, Zurich University Hospital
🇨🇭
Zurich, Switzerland