Anaesthetic challenges in a patient with Axenfeld Rieger Syndrome.

Axenfeld Rieger Syndrome (ARS) is a rare autosomal dominant disorder (1 in 200,000) with variable morphology characterized by malformations of the anterior segment of the eye along with other abnormalities.

Iris hypoplasia, iridocorneal adhesions, corectopia, polycornea, glaucoma are the usual ocular manifestations.[1] Craniofacial, dental, umbilical anomalies and congenital heart defects are also seen with ARS.[23] We report a case of a 3 year-old female child, a known case of ARS, who presented to us for examination under anesthesia (EUA) of both the eyes.

The patient was a 3 year-old girl with no family history of ARS. She was first taken to ophthalmology clinic at 6 months of age when her parents noticed squinting of her eyes. Further workup confined the presence of glaucoma in both of her eyes. Slit lamp examination revealed a prominent Schwalbe's line in all quadrants of both the eyes. There was no anomaly of the lens or fundus. A diagnosis of ARS was made.

It was decided to take her up for EUA along with tonometry, refraction testing and fundus examination. Her preoperative investigations were all within normal limits. Examination revealed maxillary hypoplasia, thin upper lip, protruding lower lip and flattening of the mid face [Figures 1 and 2]. She also had hypodontia [upper two incisors and two canines were missing] for which fixed dentures had been put [Figure 3]. Rest of the systemic examination was normal though her electrocardiography showed clinically insignificant t wave inversion in leads V 1 – V3. She was taken up in OT and sedated with inj fentanyl 2 μg/kg and midazolam 0.02 mg/kg aided with a mixture of O2, N2O and sevoflurane via facemas. But as soon as plane of anesthesia was deepened, patient went into respiratory depression and mask ventilation became difficult. Her saturation dipped to 89% from 98%. Mandibular maneuvers did not improve mask ventilation, so a laryngeal mask airway #2 was inserted immediately and her SPO2 gradually improved. Her EUA was started and lasted for around 15-20 min. Her LMA was removed only when she was completely awake and she was shifted to recovery room where her stay for next 2 hours was uneventful.

Figure 1

Maxillary hypoplasia and flattening of the mid face

Figure 2

Maxillary hypoplasia

Figure 3

Artificial dentures for missing teeth

Axenfeld in 1920 first described a gray white circular line on the posterior surface of the cornea near the limbus, with iris strands extending from the peripheral iris to this prominent line. He termed this condition as Axenfelds anomaly.[4] Rieger reported similar cases associated with other nonocular anomalies, with additional changes in iris and called it Rieger's anomaly.

ARS has been associated with mutations of the known genes PITX2[the pituitary homeobox 2 gene] at 4q25[5] and FOXC 1 [the forkhad box C1 gene FKHLT] at 6p25.[6]

Extraocular manifestations include maxillary hypoplasia, hypertelorism, telecanthus, hypodontia, oligodontia, microdontia. Other anomalies include those of pituitary gland, middle ear deafness, heart defects, hypospadias, short stature and mental retardation.[1]

Anesthetic considerations include a detailed history to confirm the diagnosis, rule out any anesthetic complication (such as difficult mask ventilation or intubation) in any previous surgery. These patients might have a difficult airway due to facial anomalies, brachycephaly and maxillary hypoplasia. Therefore a detailed airway examination is mandatory along with preparation of the difficulty airway cart in the operation theatre. A complete cardiovascular workup to rule out congenital cardiac anomalies such as interatrial septal defects, semilunar valve stenosis or insufficiencies is advocated.[7] These patients might also have communicating hydrocephalus, psychomotor retardation or hypotonia. So preoperative councelling and maintenance of ICP (intra cranial pressure) in the perioperative period is required.

To conclude ARS is a rare disorder with great genetic and morphologic variability. The concomitant occurrence of dental, craniofacial and cardiovascular anomalies can be quiet challenging even to an experienced anesthesiologist. Though EUA is a short procedure and does not require endotracheal intubation in most of the cases, an exhaustive and meticulous physical examination can avoid any catastrophe occurring during the perioperative period, especially due to difficult airway.