The porcine retinal vasculature accessed using an endovascular approach: a new experimental model for retinal ischemia.
OBJECTIVE
The aim of this study was to examine whether the retinal circulation in the pig can be accessed using interventional neuroradiology and to explore the possibility of creating occlusions that result in experimental retinal ischemia.


METHODS
Six experiments were performed using 100-kg pigs. The external carotid system was catheterized using a fluoroscopy-monitored, transfemoral, endovascular approach. Transient and permanent vascular occlusions were performed using an angioplasty balloon catheter or a liquid embolic agent that was administered via an injection-catheter.


RESULTS
A technique for transfemoral catheterization of arteries supplying the retina was established. The ophthalmic artery was demonstrated to give rise to the main ciliary artery from which the retinal artery branched as a single artery or as several arteries. A balloon-catheter could be introduced into the ophthalmic artery but not into the main ciliary artery. An injection-catheter could, in all experiments, be introduced into the main ciliary artery and, in some experiments, into the retinal artery. Occlusion of the ophthalmic artery, over the branching of the main ciliary artery, caused incomplete ischemia, presumably because of collaterals feeding the distal parts of the vasculature. Multifocal ERG (mfERG) recordings showed decreased amplitudes and increased implicit times, indicating retinal ischemia. Occlusion of the ciliary and retinal arteries caused complete ischemia, as shown by complete flattening of the mfERG recordings and, by indirect ophthalmoscopy, blanching of the retinal arteries and a pale retina,


CONCLUSIONS
The authors show for the first time that the ophthalmic and retinal artery can be catheterized using a transfemoral endovascular approach. This technique may be useful to produce clear-cut experimental retinal ischemia.
Morén
Håkan
H
Department of Ophthalmology, Lund University, Lund, Sweden.
Undrén
Per
P
Gesslein
Bodil
B
Olivecrona
Göran K
GK
Andreasson
Sten
S
Malmsjö
Malin
M
D000818:Animals; D021721:Balloon Occlusion; D001775:Blood Circulation; D002342:Carotid Artery, External / Q000000981:diagnostic imaging; D002533:Cerebral Angiography; D004121:Dimethyl Sulfoxide / Q000627:therapeutic use; D004195:Disease Models, Animal; D004621:Embolization, Therapeutic; D005260:Female; D007511:Ischemia / Q000209:etiology*; D008297:Male; D009880:Ophthalmic Artery / Q000473:pathology*; D011145:Polyvinyls / Q000627:therapeutic use; D012039:Regional Blood Flow; D015356:Retinal Artery Occlusion / Q000150:complications*; D012164:Retinal Diseases / Q000209:etiology*; D013552:Swine
C505752:Onyx HD 500; D011145:Polyvinyls; D004121:Dimethyl Sulfoxide