445 - Surgical Treatment of Seizures in Children

omy with resection of the portion of the brain contributing to the seizure activity. Currently, more frequently occurring surgical advancements include, but are not limited to, the use of: 1. Stereotactic magnetic resonance imaging (MRI) guided laser ablation of the epileptogenic foci 2. Deep brain stimulation (DBS) 3. Vagus nerve stimulation (VNS) techniques. While using small incisions and burr holes, stereotactic magnetic resonance imaging or MRI-guided laser ablation involves using small applicators that work in conjunction with optical fibers, laser energy, and magnetic resonance (MR) thermal imaging to ablate targeted brain tissue (Wil- lie, et al., 2014). Similarly, DBS is a therapy applied to drug- resistant forms of epilepsy for which resective surgery can- not be applied (Kahane & Depaulis, 2010). DBS is a surgical procedure that involves implanting electrodes into certain areas of the brain. The electrodes then produce electrical impulses that help aid in regulating abnormal brain impuls- es. These electrical impulses delivered are controlled by a generator that is placed in a “pocket” underneath the skin, usually in the superior chest. Last, VNS prevents seizures by sending mild pulses of electrical energy to the brain by way of electrodes (a wire like device) that is wrapped around the vagus nerve, located laterally to the midline of the neck. Like DBS, there is a kidney shaped battery/gen- erator that is tunneled and secured in a “pocket” on the patient’s chest. Like other common surgical advancements, these techniques are considered minimally invasive epilep- sy surgeries (MIES), in comparison to the traditional open craniotomy approach. PROCEDURAL STEPS FOR AN OPEN CRANIOTOMY RESEC TION Anatomical Considerations The anatomical structures in this article will be descriptive of the anatomy for a traditional open craniotomy for a focal cortical resection. There are various anatomical possibili- ties depending upon the specific approach for each patient, the diseased or epileptic portion of the brain must be con- sidered. The anatomical description below is generalized to describe basic anatomy related to an open craniotomy. Prior to epilepsy surgery, patients undergo a series of neurodiagnostic tests to pinpoint the area of the brain that is contributing to the seizure activity. This portion of the brain is often referred to as the sick or diseased portion of the brain. Along with an MRI, a detailed neurodiagnostic report called an electroencephalography (EEG) will help guide the surgeon to the area where the incision must be made, anatomically. Patient Positioning, Prepping and Draping Once the patient has been moved to the operating room table, the patient remains in the supine position for the placement of their endotracheal tube, intravenous and arterial access, Foley catheter, and other patient monitor- ing devices. Once the patient is ready to be positioned, the surgeon will carefully place the Mayfield skull clamp system onto the patient. Careful consideration is taken in decid- ing whether pediatric or adult skull clamp pins are used – depending upon patient age and size. Once the Mayfield skull clamp system is secured, the patient is then moved toward the head of the OR table so that the head is fully suspended in the Mayfield headrest system, with consid- eration of the operative side being positioned and exposed appropriately. During this time, the surgeon is using cau- tion in stabilizing the head and neck, while anesthesia care- fully monitors the patient’s airway. Appropriate position- ing devices and padding are placed to reduce the risk of intraoperative pressure sores. Once the patient is positioned steps are taken to set up MRI and navigation techniques being used. Typically, this process involves integrating navi- gation software with the patient’s MRI, to improve accuracy. Prior to prepping, the surgical time out is performed. Before the site can be surgically prepped, a non-sterile prep- aration may take place. Depending on where the incision is going to be made, the patient’s hair may need to be shaved and secured. A skin marker is used to mark the incision. The surgeon, resident, or circulating nurse prep the surgi- cal site with chlorhexidine-gluconate and alcohol or povi- done-iodine scrub/paint and alcohol. Once the prep is dry, the patient is draped by the surgeon and CST using sterile towels or surgical utility drapes, a skin stapler, antimicro- bial incise drape, split drape, and ¾ drape. The CST secures suction tubing x2, bipolar and monopolar cautery, naviga- tion stylet, drill cord, and possibly the cavitronic ultrasonic surgical aspirator (CUSA) to the drape. Surgical Procedure Steps Exposure. Prior to incision, the surgeon injects local anes- thetic to the site. An incision is made using a #10 or #15 blade over the area of interest. Electrocautery is used to cauterize bleeding scalp vessels. To establish hemostasis, Raney clips may be applied. Bipolar cautery is used to cau- terize delicate tissues and vessels. Raney clips are applied | The Surgical Technologist | JANUARY 2021 20