Biocompatibility and healing process of polyester meshes in the brain: in vivo examination in rats.
OBJECTIVE
To analyze the biocompatibility of multifilament polyester (PET) meshes used for the implantation of auditory brainstem implants in a standardized Wistar rat model (n=29).


METHODS
The physical properties of the meshes were examined during surgery. Using a modified plastic embedding, the local tissue reaction and the stability of mesh position in the region of the fourth ventricle were evaluated in section series from day 3 to 64. The cellular reaction was further differentiated using transmission and scanning electron microscopy.


RESULTS
PET meshes were stable for handling. However, sharp edges inevitably led to brainstem and cerebellar penetration in some cases. The meshes were preserved in situ in all section series. Positioning was stable with one exception. A sufficient fibroblast and collagen fiber encasement was reached after 14 days. In all cases, no further change was observed through day 64. The host-defense reaction was persistent and characterized by numerous macrophages and foreign-body giant cells. Bacterial infection occurred in three cases.


CONCLUSIONS
PET meshes proved to have an acceptable biocompatibility regarding local-tissue reaction in the brain. Modified polymer structures should be developed to reduce risk of injury. Anti-inflammatory surface treatments and monofilament meshes could reduce the infection rate.
Quester
Ralf
R
Center for Neurosurgery, Stereotactic and Functional Neurosurgery Clinic, Faculty of Medicine, University of Cologne, Germany. ralf.quester@uni-koeln.de
Hermanns
Benita
B
Klosterhalfen
Bernd
B
Schröder
Roland
R
Klug
Norfrid
N
D000818:Animals; D001672:Biocompatible Materials; D001921:Brain / Q000601:surgery* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D011091:Polyesters; D019736:Prostheses and Implants; D051381:Rats; D012886:Skull; D014945:Wound Healing / Q000502:physiology*
D001672:Biocompatible Materials; D011091:Polyesters