Introduction

Retinoblastoma is the most common eye neoplasm in children. It accounts for 2.5% to 4% of all Pediatric tumours, with an incidence in the USA and Europe of 2 to 5 cases per million [1]. It carries a significant hereditary component [2], with an autosomal dominant inheritance pattern associated with the RB1 gene mutation, which could lead to visual impairment in more than one family member. Until '90, the treatment of RB was based on enucleation and radiotherapy, which eventually evolved into systemic chemotherapy. To generate a more localized treatment to prevent systemic adverse reactions while preserving the eye, novel treatments have emerged, such as the Super-Selective Intra-Arterial Chemotherapy of the Ophthalmic Artery (SOAC) [3]. Unlike systemic chemotherapy, this super selective treatment requires the patients to be under general anaesthesia. Here we present two cases of patients with RB treated with SOAC and presented severe cardiovascular adverse events.

Case Reports

Case 1 A 5-year-old male patient with left congenital retinoblastoma is admitted for a second chemotherapy session of SOAC. Previous without any complications. The anaesthesia induction was done with sevoflurane 4% and O2 , and anaesthesia maintenance with sevoflurane and remifentanil, in addition to atropine 0.1 mg IV. After canalization of the ophthalmic artery, the patient presented a sudden decrease of pulmonary distention, hypoxemia (SaO2 30%), and bradycardia that soon converted into pulseless electrical activity. Code blue was activated, and CPR maneuvers were executed, including 10 µcg/kg of adrenaline and cardiac massage during 3 min. The patient returns to spontaneous circulation, and the chemoembolization was changed from super selective to non-selective chemotherapy in the internal carotid artery. The patient was transferred to the paediatric ICU. With favourable evolution, it was extubated at 24 hours post-surgery and discharged without any neurological deficit three days after. Case 2 A 17-month-old female patient with a diagnosis of bilateral retinoblastoma was admitted for the second session of SOAC. Family history included RB in her father and aunt from her father's side of the family. The patient had received systemic chemotherapy with Melphalan and the first session of SOAC that did not present with any complication. For the second session of SOAC, the patient received anaesthetic induction with inhaled propofol, and rocuronium, and general anaesthesia balancing remifentanil and sevoflurane. The patient presented a decreased saturation (82%) and hypotension (MAP<45 mmHg) with bradycardia (60 bpm), during the canulation of the ophthalmic artery. Epinephrine 100 µcg were administered and improved the hemodynamic and respiratory parameters. The procedure was finalized without any additional complications and patients were extubated after the procedure.

Discussion

Japanese investigators were the first to administered intravitreal and intra-arterial chemotherapy for advanced or recurrent retinoblastoma [4]. From their experience, SOAC has been considered a safe procedure, with few complications mainly associated with vitreous hemorrhage, atrophia of the pigmented tissue of the retina, retinal detachment, and microemboli in the eye. Some publications have reported respiratory alterations associated with the canulation of the ophthalmic artery. Phillis et al. described a case series that reported an incidence of respiratory alterations in 24% of cases [5], and Kato et al. in a retrospective study,reported in 64% of patients a severe decrease of pulmonary distension [6]. These changes are clinically similar to that of bronchospasm, which are associated with sudden changes in tidal volume and hypoxemia, leading to hypotension and bradycardia. The cardiorespiratory events that occur due to the SOAC have been described previously [5-7], and they occur in 20-30% of patients [6]. The symptoms are similar to bronchospasm or anaphylaxis. The onset of these symptoms correlates with the catheterization of the ophthalmic artery and primarily affects pulmonary distensibility [7]