P-028 Ophthalmic artery flow direction changes in intra-arterial treatment of retinoblastoma

Introduction/Purpose The introduction of catheter-administered intra-arterial chemotherapy (IAC) has changed the treatment paradigm for retinoblastoma (RB), the most common ophthalmologic malignancy in children. The variable nature of ophthalmic artery flow has led to the development of multiple endovascular techniques for drug delivery. These methods are based on the direction of ophthalmic artery filling, either retrograde from anastomoses with branches of the external carotid artery (ECA) or anterograde from the internal carotid artery (ICA). These include direct catheterization of the ophthalmic artery, ECA branch selection, use of an ICA balloon occlusion with proximal IAC administration, and balloon occlusion of the ECA to halt anastamotic flow to the OA.We sought to evaluate both direction of ophthalmic artery flow at the onset of IAC, as well as identify reversal of ophthalmic artery flow during the course of treatment. Materials and Methods We performed a retrospective analysis of the most recent 15 consecutive patients with RB who completed treatment with IAC at our tertiary care center. Results Of the 15 patients, 18 eyes were treated with IAC. 46% had left-sided disease (n=7), 33% had right-sided disease (n=5), and 20% had bilateral disease (n=3). The majority were male (n=10). Average age at the start of treatment was 1 year 5.5 months. A total of 66 treatments were performed, with a median of 4 per patient or 3.5 per involved eye. Of the 18 eyes treated, 12 (66%) initially had anterograde ophthalmic artery flow. Drug delivery was accomplished using direct ophthalmic catheterization (n=35), ICA balloon technique (n=18), ECA balloon technique (n=7), and via ECA branch catheterization (n=6). A flow reversal event was observed a total of 5 times (28% of eyes), each necessitating a change in drug delivery technique. All 5 events were in patients receiving multi-agent chemotherapy. These events occurred in 4 patients and involved 5 separate eyes, never more than once per eye. Flow reversal events were seen in both eyes (left=3, right=2). On average, events occurred between the third and fourth treatment (range 2 to 6). No correlation was found between reversal event and treatment technique. Conclusions Ophthalmic artery flow is variable in RB patients treated with IAC. Further, mid-treatment shifts between anterograde and retrograde ophthalmic artery filling are common and necessitate variation in delivery methods throughout a single treatment course. In our analysis all flow reversal events were associated with multi-agent chemotherapy (as opposed to Melphalan alone). Although the correlation was not statistically significant,our analysis is limited by power. Future investigation is necessary to elucidate the nature of these variations, such as if they are a direct response to the number of chemotherapy agents utilized. Regardless, interventionalists should be comfortable and prepared to use various techniques independent of a given patient’s treatment history. Disclosures M. Feldman: None. H. Grimaudo: None. S. Roth: None. H. Vance: None. A. Daniels: None. M. Froehler: 1; C; Genentech, Medtronic, Stryker, Microvention, and Penumbra. 2; C; Genentech, Medtronic, Stryker, Balt USA, Viz.ai, and Corindus.