Risk factors for acute choroidal ischemia after intra-arterial melphalan for retinoblastoma: the role of the catheterization approach.

PURPOSE To identify risk factors for acute choroidal ischemia (ACI) after intra-arterial chemotherapy (IAC) for retinoblastoma. DESIGN Retrospective cohort study PARTICIPANTS: 220 patients (248 eyes) treated with IAC in Lausanne between November 2008 and September 2019 (665 procedures). All cases were evaluated on a monthly basis with fundus photography and fluorescein angiography before and after each IAC. METHODS ACI, defined as any new choroidal ischemia clinically diagnosed within 35 days after an IAC, were noted. Eyes with choroidal complications diagnosed later than 35 days after the last IAC (n=7) or those where the status of the choroid was not assessable (n=35) were excluded. Specific procedure parameters and treatment regimen were compared between the group of eyes with and those without ACI. MAIN OUTCOME MEASURES Procedure-related risk factors for ACI after IAC and visual acuity assessment in the group of eyes with ACI. RESULTS ACI developed in 35 out of 206 included eyes after a mean of 2 injections. There were no differences between the two study groups regarding age at first IAC, disease grouping at diagnosis, previous given treatments, number of IAC, drug dose, mean injection time, injection mode (pulsatile versus continuous) or concomitant intravitreal melphalan. Treatment regimen (melphalan versus combined melphalan plus topotecan)(P<0.05), catheterization route (internal carotid artery versus external carotid/posterior communicating artery)(P<0.001) and catheterization type (occlusive into the OA versus non-occlusive)(P<0.001) were included in multivariate analysis and occlusive catheterization was identified as an independent risk factor for ACI (P<0.001). In the subgroup undergoing an occlusive procedure, placement of the catheter tip into the OA distal third versus medial and proximal thirds (P=0.04), and a mean catheter diameter to OA lumen ratio of ≥ 0.6 (P<0.001) were significantly correlated with ACI. Complete vision loss was noted in 27% of the eyes with ACI that were old enough for visual assessment (n=9/33), while 33% maintained a useful vision ranging between 0.1 and 0.8 (n=11/33). CONCLUSIONS Catheterization of the OA should be attempted from an ostial position or an external carotid approach to minimize the risk of potentially vision-threatening choroidal complications.