BACKGROUND AND OBJECTIVE: Serious adverse cardiorespiratory events complicate super selective ophthalmic artery chemotherapy for retinoblastoma in anesthetized children. Their mechanism remains unclear but may be attributed to an autonomic nervous reflex induced by the catheter close to the ophthalmic artery. Inadequate depth of anesthesia during catheter stimulation might be an aggravating factor. Thus, we tested whether deep general anesthesia reduced the incidence of serious cardiorespiratory events. METHODS: Children were prospectively included in this observational study. Standardized deep general anesthesia with sevoflurane, rocuronium, and sufentanil was administered. Sevoflurane MAC was kept between 1.5 and 1.7 and additional sufentanil administered. Serious cardiorespiratory event criteria were predefined and included arterial hypotension, bradycardia, and severe decrease in lung compliance. They were recorded and the factors influencing their occurrence were investigated. RESULTS: One hundred fifteen procedures were performed on 32 children. The median MAC of sevoflurane was 1.5 and median BIS value was 44. Serious cardiorespiratory events occurred in 20% of procedures and were mainly severe decrease in lung compliance (83% of events). All of them required active treatment. One procedure was aborted due to cardiorespiratory compromise and required an epinephrine infusion. All severe decreases in lung compliance occurred within 2 minutes after catheter insertion in the ophthalmic artery. No recorded demographic and endovascular characteristics were associated with serious cardiorespiratory events. CONCLUSION: Serious cardiorespiratory events occur commonly during super selective ophthalmic artery chemotherapy. Standardized deep anesthesia with analgesia did not appear to be protective. No predictive factors were identified, but these events systematically arose within 2 minutes after ophthalmic artery catheter insertion. Anesthetists and neuroradiologists should be prepared to manage these serious complications and parents should be informed of the risks.