Management of Urgent Cesarean Delievery for Parturient with Type 1 Chiari Malformation
Abstract Number: S3D-7
Abstract Type: Case Report/Case Series
Chiari Malformation (CM) is a congenital neurological anomaly associated with downward displacement of the cerebellum and brain stem through the foramen magnum. Type 1 is the most common type but it is still rare and estimated to be present in 0.5% of the population. Concurrent syringomyelia have been reported in up to 75% of these patients. (1) Given CM’s rarity, there lacks a consensus regarding management causing a challenge for the obstetric anesthesiologists.
A 26-year-old female, G4P3 , with history of asthma and CM-I diagnosed 3 years prior while evaluating a complaint of visual disturbances . Physical exam showed a patient with BMI 41, in mild distress from uterine contractions, hemodynamically stable with Mallampati III . Patient denied headaches, paresthesia, abnormal gait, or any recent visual disturbances. Patient had a previous MRI that demonstrated a low-lying cerebellar tonsils extending approximately 6 mm below the foramen magnum with crowding at the foramen magnum. Shortly after presentation, the obstetrician decided an emergent cesarean delivery was needed due to fetal distress. Following a complete physical assessment with a history focused on her CM diagnosis and review of her brain MRI, spinal anesthesia was selected. A single-shot spinal was performed at L3-4 using a 24G pencil-tip needle. Hemodynamics were tightly controlled with an infusion of ringer lactate and boluses of phenylephrine and ephedrine. The patient had an uneventful postpartum course without any neurological sequelae.
Controversy surrounds the most appropriate anesthetic for the parturient with CM type 1. With dural puncture, spinal anesthesia risks the possibility of brain herniation due to further downward displacement of the cerebellar tonsils through the foramen magnum. However, there are significant risks that also exist with general anesthesia. There is a well-known four time increase in airway complications in the OB population. This patient had an unfavorable airway exam coupled with morbid obesity elevating these concerns. Additionally, the intubation that is required for general anesthesia risks a significant increase in the ICP which can be more profound in the pregnant population. This increased ICP could also worsen the brain herniation and associated symptoms. (2,3)
In our case, the patient had been asymptomatic with no recent visual disturbances. Her cerebellar tonsillar descent was not extensive (6.4 mm). Due to the emergent timing of the case, there wasn’t any time to obtain neurological consultation. A spinal was performed with a pencil point needle in order to diminish the risk of continued CSF leak. Our decision was based on the patient’s clinical presentation and documented reports that supported neuraxial’s use in a similar context.
1. Anesthesiology. 2013; 119: 703-718
2. Case Rep Anesthesiol. 2013; 2013: 512915
3. Surg Neurol Int. 2017; 8: 10.