Histological demonstration of healing in experimental aneurysms.
BACKGROUND
Recanalisation of aneurysms after interventional therapy is still an unsolved problem. The aim of this study is to demonstrate the angiographic and histological evidence of healing after endovascular embolisation of experimental aneurysms.


METHODS
We evaluated the healing reaction in experimental aneurysms treated with HydroCoils and platinum coils. After microsurgical construction of aneurysms in 24 rabbits, embolisation was performed. Four animals were sacrificed immediately after embolisation and 5 after 1 month, 3 months and 6 months, respectively, the remaining served as control group. Serial plastic-embedded ground sections of the parent arteries-aneurysm complexes were evaluated by light microscopy.


RESULTS
Thrombus organisation in the aneurysms resulted in fibrovascular tissue formation between bare platinum and HydroCoils from the walls of the aneurysms towards the centre of the sac over time. In the clefts between HydroCoils only thin strands of granulation tissue were observed. From one month on, there was a neointimal layer covering the coil mass at the aneurysm orifice.


CONCLUSIONS
Progressive occlusion by the expanding hydrogel polymers on the coils seemed to result in a durable healing reaction in the aneurismal sac in a short-term follow-up period.
Department of Neurology/Neuroscience Institute, Christian Doppler Clinic, Paracelsus Medical University, Salzburg, Austria. m.killer@salk.at
M
M
Killer
H
H
Plenk
B
B
Minnich
R
R
Al-Schameri
A
A
Lametschwantner
B
B
Richling
D000818:Animals; D004195:Disease Models, Animal; D004621:Embolization, Therapeutic / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D005355:Fibrosis / Q000503:physiopathology; D006097:Granulation Tissue / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000494:pharmacology / Q000627:therapeutic use; D002532:Intracranial Aneurysm / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D010984:Platinum / Q000494:pharmacology / Q000627:therapeutic use; D011183:Postoperative Complications / Q000517:prevention & control; D019736:Prostheses and Implants; D011817:Rabbits; D055502:Secondary Prevention; D017539:Tunica Intima / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology*
D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D010984:Platinum