d Principles of Intraoperative Management of Early-Onset Scoliosis
Ashok N. Johan, Rashid Anjum, and Vrushali Ponde
Introduction: Can Early-Onset Scoliosis (EOS) Be Managed in Resource-Limited Settings?
The management of early-onset scoliosis (EOS) has seen tremendous advancement in the past decade. EOS is frequently associated with obstructive pulmonary disease and dyspnoea, among others, and these are considered more troublesome than the deformity itself [1, 2]. Thoracic cage abnormalities pose the greatest risk for developing restrictive pulmonary disease [3]. The lung parenchyma and bronchial tree are fully developed by 8 years of age, and by 10-years, thoracic volume is half that of an adult [4, 5]. To allow continued growth of the spine and thorax while controlling progression of deformity, growth-friendly surgical options emerged, such as traditional growing rods, VEPTR (vertical expandable prosthetic titanium rib), and, recently, the magnetically controlled growing rods (MCGR). The goal of treatment in EOS is not only deformity correction, but also allowing continued growth [5, 6]. The recent shift from fusion to fusionless surgery has promised the same, but it is not without complications. Hence, the most important consideration is to have an absolute indication for the surgery prior to evaluation of other parameters. The management of EOS is quite possible in resource-limited conditions, provided the proper preoperative evaluation, intraoperative and post operative management is meticulously undertaken. There should be a proper operative setup (Figure 8d.l) with all the required equipment and personnel for the safe and effective treatment of EOS patients.
Preoperative Considerations That Will Have a Bearing on Intraoperative Management
The preoperative evaluation for patients with EOS comprises of a series of assessments. This is to ensure that the patient is an appropriate candidate for the selected treatment method. A preoperative visit to assess the risk, such as a difficult airway and identification of preexisting pulmonary disease; optimise through physiotherapy and bronchodilator; provide a detailed explanation of the intraoperative wake-up test (very unlikely that neuromuscular monitoring will be implemented in limited-resources setting); and connect with the family is indispensable. History of effort tolerance in terms of the child’s playing ability or stamina and the breathholding time (BHT) should give an apt clinical judgment of the cardiopulmonary reserve. Collection of the complete blood count, cross matching, coagulation profile, and urea electrolytes is mandatory.
FIGURE 8D.1 A well-equipped operation theatre allows peaceful spine deformity surgery.
Respiratory System
The pulmonary system may be the main indication for intervention; therefore, its preoperative status is likely to be impaired in many patients, requiring a chest physician and an anaesthe-siologist consultation preoperatively [7]. The most important measure of respiratory system function is a pulmonary function test (PFT) and should be obtained whenever possible; however, it is not possible to perform PFTs in children younger than 5 years of age. A PFT helps to provide objective criteria for active treatment and is well documented as the best prognostic test for postoperative respiratory morbidity. In circumstances in which a PFT cannot be performed, magnetic resonance imaging (MRI) or fluoroscopy to evaluate diaphragm or chest wall movement are important predictors of possible postoperative respiratory status [8]. Adequate measures should be taken to prevent reflux aspiration. A tracheostomy should be considered for patients with anomalies of the cervical spine that limit neck motion, which may make intubation difficult, or have an increased risk of spinal cord compression if occult instability is present.
Curve Type and Cord Status
Preoperative evaluation of the curve type, length, flexibility, and instrument construct is pivotal. Anteroposterior (AP) and lateral x-ray scanogram of the whole spine are needed to describe the curve pattern and sagittal and coronal balance. Bending films are also taken to elicit the flexibility of curve and finalisation of anchor points. The status of the spinal cord is ascertained with an MRI to rule out occult spinal dysraphism (OSD) with intraspinal anomalies such as diastematomyelia and tethering of the cord. If a neurosurgical intervention is required, it is undertaken prior to any planned deformity correction or along with it.
