The porcine retinal vasculature can be accessed using an endovascular approach, a new experimental model for retinal ischemia.

Purpose. The aim was to examine if the retinal circulation in the pig can be accessed using interventional neuroradiology and to explore the possibility to create occlusions that result in experimental retinal ischemia. Methods. Six experiments were performed using 100 kg pigs. The external carotid system was catheterizised using 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 or 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 due to collaterals feeding the distal parts of the vasculature. 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. We prove for the first time that the ophthalmic and retinal artery can be catheterizised using a transfemoral endovascular approach. This technique may be useful to produce clear-cut experimental retinal ischemia.