Hemodynamic and Anatomic Variations Require an Adaptable Approach during Intra-Arterial Chemotherapy for Intraocular Retinoblastoma: Alternative Routes, Strategies, and Follow-Up

Abstract

Background and purpose: Intra-arterial chemotherapy for retinoblastoma is not always a straightforward procedure, and it may require an adaptable approach. This study illustrates strategies used when the ophthalmic artery is difficult to catheterize or not visible, and it ascertains the effectiveness and safety of these strategies.

Materials and methods: A retrospective study was performed on a series of 108 eyes affected by intraocular retinoblastoma and selected for intra-arterial chemotherapy (follow-up range, 6-82 months). We recognized 3 different patterns of drug delivery: a fixed pattern through the ophthalmic artery, a fixed pattern through branches of the external carotid artery, and a variable pattern through either the ophthalmic or the external carotid artery.

Results: We performed 448 sessions of intra-arterial chemotherapy, 83.70% of them through the ophthalmic artery and 16.29% via the external carotid artery. In 24.52% of eyes, the procedure was performed at least once through branches of the external carotid artery. In 73 eyes, the pattern of drug delivery was fixed through the ophthalmic artery; for 9 eyes, it was fixed through branches of the external carotid artery; and for 17 eyes, the pattern was variable. Statistical analysis did not show any significant difference in the clinical outcome of the eyes (remission versus enucleation) treated with different patterns of drug delivery. Adverse events could not be correlated with any particular pattern.

Conclusions: Alternative routes of intra-arterial chemotherapy for intraocular retinoblastoma appear in the short term as effective and safe as the traditional drug infusion through the ophthalmic artery.

Fig 1.

An exemplary case of adaptable approaches to the IAC. The patient has bilateral retinoblastoma previously enucleated on 1 side (the prosthesis is visible). The remaining eye is a case of VP of drug delivery. A, The OA is successfully catheterized and used in 2 sessions of IAC because the choroidal blush (arrows) is regularly achieved. B–E, Third session of IAC. Selective angiography of the ICA does not show any visible OA (B). Nevertheless catheterization of the OA is successful (C), though the contrast medium flows back into the ICA (On-line Video). Superselective angiography of the MMA shows a good anastomotic pathway to the OA (D), which allows achieving the choroidal blush (arrows in E). F and G, Fourth session of IAC. This time the anastomosis between the MMA and the OA does not guarantee the choroidal blush. An alternative route for drug delivery through the ECA is sought and found between the frontal branch of the superficial temporal artery (arrows point to the microcatheter within the artery) and the supratrochlear artery (F). A later angiographic phase shows that this pathway guarantees the choroidal blush (arrows) (G). H–J, Fifth session of IAC. The anastomosis between the MMA and the OA is working again. However, the contrast medium flows back even into a large branch of the MMA (arrows in H). To reduce the volume of distribution, we glued the meningeal branch (arrows point to the cast in I), and the following injection of contrast medium achieves the choroidal blush (arrows in J).

Fig 2.

Particular angiographic procedures. A, Customization of the microcatheter. The tip of the microcatheter (black arrow), manually bent to fit the angioanatomy of the patient, has been firmly placed at the entrance of the OA to release the contrast medium (white arrows). B–D, Flow anterograde redirection within the OA. Anteroposterior projections. Contrast medium injection into the superficial temporal artery shows a rich network of small vessels connecting the superficial temporal artery with the OA (B). Embolization of the arterial network. The cast of glue outlines the embolized frontal vessels (arrows in C). The flow in the OA, redirected anterogradely (D), allows achieving the choroidal blush (arrows in D).