James M. Drake
Roukoz B. Chamoun, Michel E. Mawad, William E. Whitehead, Thomas G. Luerssen and Andrew Jea
Currently, no diagnostic or treatment standards exist for extracranial carotid artery dissection (CAD) in children after trauma. The purpose of this study was to review and describe the characteristics, diagnosis, and treatment of this rather uncommon sequelae of pediatric trauma.
A systematic review of the literature was performed to examine the pertinent studies of traumatic extracranial carotid artery (CA) injuries in children.
No randomized trials were identified; however, 19 case reports or small case series consisting of 34 pediatric patients were found in the literature. The diagnosis of CAD was made in 33 of 34 patients only after the onset of ischemic symptomatology. Twenty-four of 34 patients underwent cerebral angiography to confirm diagnosis; MR angiography affirmed the diagnosis in 6 of 34 patients. There was little published experience with CA ultrasonography or CT angiography for diagnosis. Thirty of 34 patients were treated with medical therapy or observation; 2 of 4 patients treated with observation alone died. There was little experience with open surgical treatment of CAD in the pediatric population, and there were no studies on the endovascular treatment of traumatic CAD in children. The literature does not support anticoagulation therapy over antiplatelet therapy.
As a result of this review of the literature, the authors propose the algorithms for the evaluation and treatment of traumatic extracranial CADs in children. These recommendations include utilizing MR angiography as a screening tool in cases in which the clinical suspicion of CAD is high, using conventional cerebral angiography to confirm the diagnosis, implementing antiplatelet therapy as initial medical management, and reserving endovascular stenting in cases of failed medical treatment.
Ashwin Viswanathan, Katherine Relyea, William E. Whitehead, Daniel J. Curry, Thomas G. Luerssen and Andrew Jea
The authors describe a rare case of pneumothorax as a complication of thoracic pedicle screw placement in an 11-year-old girl undergoing posterior segmental instrumentation for a kyphotic deformity. Spontaneous pneumothorax after posterior fusion for adolescent idiopathic scoliosis has been reported in the orthopedic literature; however, to the best of the authors' knowledge, pneumothorax directly related to pedicle screw placement for spinal deformity has not been previously described. The authors discuss the anatomical and technical aspects leading to this complication and the lessons learned from it.
Sandi Lam, Thomas G. Luerssen, William E. Whitehead, Andrew Jea and I-Wen Pan
Roukoz B. Chamoun, William E. Whitehead, Daniel J. Curry, Thomas G. Luerssen and Andrew Jea
The use of C-1 lateral mass screws provides an alternative to C1–2 transarticular screws in the pediatric population. However, the confined space of the local anatomy and unfamiliarity with the technique may make the placement of a C-1 lateral mass screw more challenging, especially in the juvenile or growing spine.
A CT morphometric analysis was performed in 76 pediatric atlases imaged at Texas Children's Hospital from October 1, 2007 until April 30, 2008. Critical measurements were determined for potential screw entry points, trajectories, and lengths, with the goal of replicating the operative technique described by Harms and Melcher for adult patients.
The mean height and width for screw entry on the posterior surface of the lateral mass were 2.6 and 8.5 mm, respectively. The mean medially angled screw trajectory from an idealized entry point on the lateral mass was 16° (range 4 to 27°). The mean maximal screw depth from this same ideal entry point was 20.3 mm. The overhang of the posterior arch averaged 6.3 mm (range 2.1–12.4 mm). The measurement between the left- and right-side lateral masses was significantly different for the maximum medially angled screw trajectory (p = 0.003) and the maximum inferiorly directed angle (p = 0.045). Those measurements in children < 8 years of age were statistically significant for the entry point height (p = 0.038) and maximum laterally angled screw trajectory (p = 0.025) compared with older children. The differences between boys and girls were statistically significant for the minimum screw length (p = 0.04) and the anterior lateral mass height (p < 0.001).
A significant variation in the morphological features of C-1 exists, especially between the left and right sides and in younger children. The differences between boys and girls are clinically insignificant. The critical measurement of whether the C-1 lateral mass in a child could accommodate a 3.5-mm-diameter screw is the width of the lateral mass and its proximity to the vertebral artery. Only 1 of 152 lateral masses studied would not have been able to accommodate a lateral mass screw. This study reemphasizes the importance of a preoperative CT scan of the upper cervical spine to assure safe and effective placement of the instrumentation at this level.
Andrew Jea, Keyne K. Johnson, William E. Whitehead and Thomas G. Luerssen
The use of spinal instrumentation to stabilize the occipitocervical junction in pediatric patients has increased and evolved in recent years. Wiring techniques have now given way to screw-rod or screw-plate techniques with or without postoperative external immobilization. Although C-2 translaminar screws have been used in these constructs, subaxial translaminar screws have not, to date, been described in either the pediatric or adult patient populations.
The authors describe the feasibility of translaminar screw placement in the C-3 lamina. Rigid fixation with translaminar screws offers an alternative to subaxial fixation with lateral mass screws, allowing for formation of biomechanically sound spinal constructs and minimizing potential neurovascular morbidity. Their use requires careful analysis of preoperative imaging studies, intact posterior elements, and avoidance of violation of the inner laminar wall.
Robert H. Rosenwasser
William E. Whitehead, Andrew Jea, Shobhan Vachhrajani, Abhaya V. Kulkarni and James M. Drake
✓ The authors present a technique in which real-time ultrasound monitoring is used to aid the insertion of cerebrospinal fluid (CSF) shunt ventricular catheters in children without patent fontanelles. Experience with the technique is reviewed.
Intraoperative ultrasound is used to identify the compartments of the lateral ventricles and the choroid plexus prior to catheter insertion. Distance and trajectory to the best location for the hole-bearing segment of the catheter are determined and the catheter is inserted while real-time ultrasound monitoring is performed. Ten pediatric patients without open fontanelles underwent CSF shunt placement with the aid of transcranial ultrasound guidance between July and December 2006. After enlarging an occipital or frontal bur hole to a diameter of 2 cm to accommodate a small-footprint ultrasound probe, a ventricular catheter was carefully advanced into the frontal or occipital horn of the lateral ventricle while continuous ultrasound monitoring was performed. All catheters were inserted with a single pass through the brain. The final position of the ventricular catheter was visualized using intraoperative ultrasound. Postoperative computed tomography scans revealed all ventricular catheters placed accurately into the intended compartment of the ventricular system (for example, frontal horn or trigone). No procedure-related complications were noted.
Real-time transcranial ultrasound monitoring through an enlarged bur hole is a feasible, safe, and effective technique for the placement of ventricular catheters in pediatric patients without a patent fontanelle.
Rob Dickerman and Ashley Reynolds
Ryan S. Kitagawa, Michel E. Mawad, William E. Whitehead, Daniel J. Curry, Thomas G. Luersen and Andrew Jea
Arteriovenous malformations (AVMs) within the spinal canal and in the paraspinal region are unusual. Spinal cord and dural AVMs or arteriovenous fistulas have been the subject of numerous reports, but paraspinal malformations causing venous congestion or hemorrhage in the spinal canal are rare and present special diagnosis and management challenges. The authors review previously published reports on 16 children with paraspinal AVMs. They also describe the 17th case of a child with a paraspinal AVM who presented with a spontaneous spinal epidural hematoma. To the best of the authors' knowledge, there has been no other case of a spinal epidural hematoma associated with a paraspinal AVM. In each of the 17 cases, the vascular lesion was successfully obliterated using endovascular therapy. Embolization with permanent occlusive agents is an effective treatment for these rare but potentially debilitating lesions.