The Sensitivity of Limited-Sequence MRI in Identifying Pediatric Cervical Spine Injury: A Western Pediatric Surgery Research Consortium Multicenter Retrospective Cohort Study

INTRODUCTION

Clinical clearance of a child's cervical spine after trauma is often challenging due to impaired mental status or an unreliable neurologic examination. Magnetic resonance imaging (MRI) is the gold standard for excluding ligamentous injury in children but is constrained by long image acquisition times and frequent need for anesthesia. Limited-sequence MRI (LSMRI) is used in evaluating the evolution of traumatic brain injury and may also be useful for cervical spine clearance while potentially avoiding the need for anesthesia. The purpose of this study was to assess the sensitivity and negative predictive value of LSMRI as compared to gold standard full-sequence MRI as a screening tool to rule out clinically significant ligamentous cervical spine injury.

METHODS

We conducted a ten-center, five-year retrospective cohort study (2017-2021) of all children (0-18y) with a cervical spine MRI after blunt trauma. MRI images were re-reviewed by a study pediatric radiologist at each site to determine if the presence of an injury could be identified on limited sequences alone. Unstable cervical spine injury was determined by study neurosurgeon review at each site.

RESULTS

We identified 2,663 children less than 18 years of age who underwent an MRI of the cervical spine with 1,008 injuries detected on full-sequence studies. The sensitivity and negative predictive value of LSMRI were both >99% for detecting any injury and 100% for detecting any unstable injury. Young children (age < 5 years) were more likely to be electively intubated or sedated for cervical spine MRI.

CONCLUSION

LSMRI is reliably detects clinically significant ligamentous injury in children after blunt trauma. To decrease anesthesia use and minimize MRI time, trauma centers should develop LSMRI screening protocols for children without a reliable neurologic exam.

LEVEL OF EVIDENCE

2 (Diagnostic Tests or Criteria).

Management of cerebrospinal fluid pseudocysts in the laparoscopic age

OBJECTIVE

Abdominal CSF pseudocysts are an uncommon but challenging complication of ventriculoperitoneal shunts. Pseudocysts consist of a loculated intraperitoneal compartment that inadequately absorbs CSF and may be infected or sterile at diagnosis. The treatment goal is to clear infection if present, reduce inflammation, and reestablish long-term function in an absorptive (intraperitoneal) space. This aim of this paper was to study the efficacy of primary laparoscopic repositioning of the distal shunt catheter for treatment of sterile abdominal CSF pseudocysts.

METHODS

All patients treated for abdominal CSF pseudocysts at Dallas Children's Health from 1991 to 2021 were retrospectively reviewed. Patient history and pseudocyst characteristics were analyzed, with a primary outcome of pseudocyst recurrence at 1 year.

RESULTS

Of 92 primary pseudocysts, 5 initial treatment strategies (groups) were used depending on culture status, clinical history, and surgeon preference: 1) shunt explant/external ventricular drain (EVD) placement (23/92), 2) distal tubing externalization (13/92), 3) laparoscopic repositioning (35/92), 4) open repositioning (4/92), and 5) other methods such as pseudocyst drainage or direct revision to another terminus (17/92). Seventy pseudocysts underwent shunt reimplantation in the peritoneal space. The 1-year peritoneal shunt survival for groups 1 and 2 combined was 90%, and 62% for group 3. In group 3, 1-year survival was better for those with normal systemic inflammatory markers (100%) than for those with high markers (47%) (p = 0.042). In a univariate Cox proportional hazards model, the risk of pseudocyst recurrence was increased if the most recent abdominal procedure was a nonshunt abdominal surgery (p = 0.012), and it approached statistical significance with male sex (p = 0.054) and elevated inflammatory markers (p = 0.056. Multivariate Cox analysis suggested increased recurrence risk with male sex (p = 0.05) and elevated inflammatory markers (p = 0.06), although the statistical significance threshold was not reached. The length of hospital stay was shorter for laparoscopic repositioning (6 days) than for explantation/EVD placement (21 days) (p < 0.0001). Ultimately, 62% of patients had a peritoneal terminus at the last follow-up, 33% (n = 30) had an extraperitoneal terminus (19 pleura, 8 right heart, and 3 gallbladder), and 5 patients were shunt free.

CONCLUSIONS

Some sterile pseudocysts with normal systemic inflammatory markers can be effectively treated with laparoscopic repositioning, resulting in a significantly shorter hospitalization and modestly higher recurrence rate than shunt explantation.

Clinical utility and interrater reliability of video urodynamics in children with isolated fibrolipoma of filum terminale

INTRODUCTION

Children with an isolated fibrolipoma of filum terminale (IFFT) but otherwise normal spinal cord are often evaluated with video urodynamics (VUDS). VUDS interpretation is subjective and can be difficult in young children. These patients may undergo detethering surgery if there is concern for current or future symptomatic tethered cord.

OBJECTIVE

We hypothesized that VUDS in children with IFFT would have limited clinical utility regarding decision for or against detethering surgery and VUDS interpretation would have poor interrater reliability.

METHODS

Patients with IFFT who underwent VUDS for from 2009 to 2021 were retrospectively reviewed to evaluate clinical utility of VUDS. 6 pediatric urologists who were blinded to patient clinical characteristics reviewed the VUDS. Gwet's first order agreement coefficient (AC1) with 95% CI was used to assess interrater reliability.

RESULTS

47 patients (24F:23M) were identified. Median age at initial evaluation was 2.8yrs (IQR:1.5-6.8). 24 (51%) patients underwent detethering surgery (Table). VUDS at initial evaluation were interpreted by treating urologist as normal in 4 (8%), reassuring for normal in 39 (81%), or concerning for abnormal in 4 (9%). Based on neurosurgery clinic and operative notes for the 47 patients, VUDS made no change in management in 37 patients (79%), prompted detethering in 3 (6%), was given as reason for observation in 7 (15%), and was normal or reassuring for normal but not documented as a reason for observation in 16 (34%) (Table). Interrater reliability for VUDS interpretation had fair agreement (AC1 = 0.27) for overall categorization of VUDS and EMG interpretation (AC1 = 0.34). Moderate agreement was seen for detrusor overactivity interpretation (AC1 = 0.54) and bladder neck appearance (AC1 = 0.46).

DISCUSSION

In our cohort, 90% of patients had a normal or reassuring for normal interpretation of VUDS. VUDS interpretation affected clinical course in a minority of patients. There was fair interrater reliability for overall VUDS interpretation and therefore clinical course regarding detethering surgery could vary depending upon interpreting urologist. This fair interrater variability appeared to be related to variability in EMG, bladder neck appearance, and detrusor overactivity interpretation.

CONCLUSION

VUDS affected clinical management in about 20% of our cohort and supported the choice for observation in around 50% of patients. This suggests VUDS does have clinical utility in pediatric patients with IFFT. The overall VUDS interpretation had fair interrater reliability. This suggest VUDS interpretation has limitations in determining normal versus abnormal bladder function in children with IFFT. Neurosurgeons and urologists should be aware of VUDS limitations in this patient population.

Cerebellar tonsil reduction for surgical treatment of Chiari malformation type I in children

OBJECTIVE

The goal of this study was to review the efficacy and safety of different surgical techniques used for treatment of Chiari malformation type I (CM-I) in children.

METHODS

The authors retrospectively reviewed 437 consecutive children surgically treated for CM-I. Procedures were classified into four groups: bone decompression (posterior fossa decompression [PFD]) and duraplasty (PFD with duraplasty [PFDD]), PFDD with arachnoid dissection (PFDD+AD), PFDD with tonsil coagulation of at least one cerebellar tonsil (PFDD+TC), and PFDD with subpial tonsil resection of at least one tonsil (PFDD+TR). Efficacy was measured as a greater than 50% reduction in the syrinx by length or anteroposterior width, patient-reported improvement in symptoms, and rate of reoperation. Safety was measured as the rate of postoperative complications.

RESULTS

The mean patient age was 8.4 years (range 3 months to 18 years). In total, 221 (50.6%) patients had syringomyelia. The mean follow-up was 31.1 months (range 3-199 months), and there was no statistically significant difference between groups (p = 0.474). Preoperatively, univariate analysis showed that non-Chiari headache, hydrocephalus, tonsil length, and distance from the opisthion to brainstem were associated with the surgical technique used. Multivariate analysis demonstrated that hydrocephalus was independently associated with PFD+AD (p = 0.028), tonsil length was independently associated with PFD+TC (p = 0.001) and PFD+TR (p = 0.044), and non-Chiari headache was inversely associated with PFD+TR (p = 0.001). In the treatment groups postoperatively, symptoms improved in 57/69 (82.6%) PFDD patients, 20/21 (95.2%) PFDD+AD patients, 79/90 (87.8%) PFDD+TC patients, and 231/257 (89.9%) PFDD+TR patients, and differences between groups were not statistically significant. Similarly, there was no statistically significant difference in postoperative Chicago Chiari Outcome Scale scores between groups (p = 0.174). Syringomyelia improved in 79.8% of PFDD+TC/TR patients versus only 58.7% of PFDD+AD patients (p = 0.003). PFDD+TC/TR remained independently associated with improved syrinx outcomes (p = 0.005) after controlling for which surgeon performed the operation. For those patients whose syrinx did not resolve, no statistically significant differences between surgery groups were observed in the length of follow-up or time to reoperation. Overall, there was no statistically significant difference between groups in postoperative complication rates, including aseptic meningitis and CSF- and wound-related issues, or reoperation rates.

CONCLUSIONS

In this single-center retrospective series, cerebellar tonsil reduction, by either coagulation or subpial resection, resulted in superior reduction of syringomyelia in pediatric CM-I patients, without increased complications.

Risk factors for clinical and radiological worsening following Chiari malformation type I surgery in the pediatric population

OBJECTIVE

Foramen magnum (FM) decompression with or without duraplasty is considered a common treatment strategy for Chiari malformation type I (CM-I). The authors' objective was to determine a predictive model of risk factors for clinical and radiological worsening after CM-I surgery.

METHODS

A retrospective review of electronic health records was conducted at an academic tertiary care hospital from 2001 to 2019. A multivariable Cox proportional hazards regression model was used to determine the risk factors. The Kaplan-Meier estimate was plotted to delineate outcomes based on FM size. FM was measured as the preoperative distance between the basion and opisthion and dichotomized into < 34 mm and ≥ 34 mm. Syrinx was measured preoperatively and postoperatively in the craniocaudal and anteroposterior directions using a T2-weighted MRI sequence.

RESULTS

A total of 454 patients (231 females [50.9%]) with a median (range) age of 8.0 (0-18) years were included in the study. The median duration of follow-up was 21.0 months (range 3.0-144.0 years). The model suggested that patients with symptoms consisting of occipital/tussive headache (HR 4.05, 95% CI 1.34-12.17, p = 0.01), cranial nerve symptoms (HR 3.46, 95% CI 1.16-10.2, p = 0.02), and brainstem/spinal cord symptoms (HR 3.25, 95% CI 1.01-11.49, p = 0.05) had higher risk, whereas those who underwent arachnoid dissection/adhesion lysis had 75% lower likelihood (HR 0.25, 95% CI 0.10-0.64, p = 0.004) of clinical worsening postoperatively. Similarly, patients with evidence of brainstem/spinal cord symptoms (HR 7.9, 95% CI 2.84-9.50, p = 0.03), scoliosis (HR 1.04, 95% CI 1.01-2.80, p = 0.04), and preoperative syrinx (HR 16.1, 95% CI 1.95-132.7, p = 0.03) had significantly higher likelihood of postoperative worsening of syrinx. Patients with symptoms consisting of occipital/tussive headache (HR 5.44, 95% CI 1.86-15.9, p = 0.002), cranial nerve symptoms (HR 2.80, 95% CI 1.02-7.68, p = 0.04), and nonspecific symptoms (HR 6.70, 95% CI 1.99-22.6, p = 0.002) had significantly higher likelihood, whereas patients with FM ≥ 34 mm and those who underwent arachnoid dissection/adhesion lysis had 73% (HR 0.27, 95% CI 0.08-0.89, p = 0.03) and 70% (HR 0.30, 95% CI 0.12-0.73, p = 0.008) lower likelihood of reoperation, respectively. The Kaplan-Meier curve showed that patients with FM size ≥ 34 mm had significantly better clinical (p = 0.02) and syrinx (p = 0.03) improvement postoperatively when the tonsils were resected.

CONCLUSIONS

These results showed that preoperative and intraoperative factors may help to provide better clinical decision-making for CM-I surgery. Patients with FM size ≥ 34 mm may have better outcomes when the tonsils are resected.

Development of best practices in the utilization and implementation of pediatric cervical spine traction: a modified Delphi study

OBJECTIVE

Cervical traction in pediatric patients is an uncommon but invaluable technique in the management of cervical trauma and deformity. Despite its utility, little empirical evidence exists to guide its implementation, with most practitioners employing custom or modified adult protocols. Expert-based best practices may improve the care of children undergoing cervical traction. In this study, the authors aimed to build consensus and establish best practices for the use of pediatric cervical traction in order to enhance its utilization, safety, and efficacy.

METHODS

A modified Delphi method was employed to try to identify areas of consensus regarding the utilization and implementation of pediatric cervical spine traction. A literature review of pediatric cervical traction was distributed electronically along with a survey of current practices to a group of 20 board-certified pediatric neurosurgeons and orthopedic surgeons with expertise in the pediatric cervical spine. Sixty statements were then formulated and distributed to the group. The results of the second survey were discussed during an in-person meeting leading to further consensus. Consensus was defined as ≥ 80% agreement on a 4-point Likert scale (strongly agree, agree, disagree, strongly disagree).

RESULTS

After the initial round, consensus was achieved with 40 statements regarding the following topics: goals, indications, and contraindications of traction (12), pretraction imaging (6), practical application and initiation of various traction techniques (8), protocols in trauma and deformity patients (8), and management of traction-related complications (6). Following the second round, an additional 9 statements reached consensus related to goals/indications/contraindications of traction (4), related to initiation of traction (4), and related to complication management (1). All participants were willing to incorporate the consensus statements into their practice.

CONCLUSIONS

In an attempt to improve and standardize the use of cervical traction in pediatric patients, the authors have identified 49 best-practice recommendations, which were generated by reaching consensus among a multidisciplinary group of pediatric spine experts using a modified Delphi technique. Further study is required to determine if implementation of these practices can lead to reduced complications and improved outcomes for children.

Dynamic compression in vertebral artery dissection in children: apropos of a new protocol

PURPOSE

Our goals are (1) to report a consecutive prospective series of children who had posterior circulation stroke caused by vertebral artery dissection at the V3 segment; (2) to describe a configuration of the vertebral artery that may predispose to rotational compression; and (3) to recommend a new protocol for evaluation and treatment of vertebral artery dissection at V3.

METHODS

All children diagnosed with vertebral artery dissection at the V3 segment from September 2014 to July 2020 at our institution were included in the study. Demographic, clinical, surgical, and radiological data were collected.

RESULTS

Sixteen children were found to have dissection at a specific segment of the vertebral artery. Fourteen patients were male. Eleven were found to have compression on rotation during a provocative angiogram. All eleven underwent C1C2 posterior fusion as part of their treatment. Their mean age was 6.44 years (range 18 months-15 years). Mean blood loss was 57.7 mL. One minor complication occurred: a superficial wound infection treated with oral antibiotics only. There were no vascular or neurologic injuries. There have been no recurrent ischemic events after diagnosis and/or treatment. Mean follow-up was 33.3 months (range 2-59 months). We designed a new protocol to manage V3 dissections in children.

CONCLUSION

Posterior C1C2 fusion is a safe and effective option for treatment of dynamic compression in vertebral artery dissection in children. Institution of and compliance with a strict diagnostic and treatment protocol for V3 segment dissections seem to prevent recurrent stroke.

Growth and alignment of the pediatric subaxial cervical spine following rigid instrumentation and fusion: a multicenter study of the Pediatric Craniocervical Society

OBJECTIVE The long-term effects of surgical fusion on the growing subaxial cervical spine are largely unknown. Recent cross-sectional studies have demonstrated that there is continued growth of the cervical spine through the teenage years. The purpose of this multicenter study was to determine the effects of rigid instrumentation and fusion on the growing subaxial cervical spine by investigating vertical growth, cervical alignment, cervical curvature, and adjacent-segment instability over time. METHODS A total of 15 centers participated in this multi-institutional retrospective study. Cases involving children less than 16 years of age who underwent rigid instrumentation and fusion of the subaxial cervical spine (C-2 and T-1 inclusive) with at least 1 year of clinical and radiographic follow-up were investigated. Charts were reviewed for clinical data. Postoperative and most recent radiographs, CT, and MR images were used to measure vertical growth and assess alignment and stability. RESULTS Eighty-one patients were included in the study, with a mean follow-up of 33 months. Ninety-five percent of patients had complete clinical resolution or significant improvement in symptoms. Postoperative cervical kyphosis was seen in only 4 patients (5%), and none developed a swan-neck deformity, unintended adjacent-level fusion, or instability. Of patients with at least 2 years of follow-up, 62% demonstrated growth across the fusion construct. On average, vertical growth was 79% (4-level constructs), 83% (3-level constructs), or 100% (2-level constructs) of expected growth. When comparing the group with continued vertical growth to the one without growth, there were no statistically significant differences in terms of age, sex, underlying etiology, surgical approach, or number of levels fused. CONCLUSIONS Continued vertical growth of the subaxial spine occurs in nearly two-thirds of children after rigid instrumentation and fusion of the subaxial spine. Failure of continued vertical growth is not associated with the patient's age, sex, underlying etiology, number of levels fused, or surgical approach. Further studies are needed to understand this dichotomy and determine the long-term biomechanical effects of surgery on the growing pediatric cervical spine.

Fluoroscopy only for the placement of long iliac screws: A study on 14 patients

Background

Iliac screw placement is challenging due to the particular anatomy of the ilium. Most series have reported the use of relatively short (≤90 mm in length) screws despite a long iliac buttress, which has an average length of 129 mm in females and 141 mm in males. This study describes a series of 14 patients who underwent placement of long iliac screws (≥100 mm in length) as part of a spinopelvic fusion utilizing fluoroscopy alone.

Methods

All patients who received at least one long iliac screw were included in this study. Placement accuracy, the average distance from the screw tip to the anterior inferior iliac spine (AIIS), neurovascular injuries, acetabulum and/or sciatic notch violations, and screw prominence were all measured.

Results

Fourteen patients received 38 iliac screws, with 31 screws being ≥100 mm in length. The accuracy rate was 87.1% (27/31) for the long iliac screws. The average shortest distance from the iliac screw tip to the AIIS was 15.5 mm for the right-sided and 17.1 mm for the left-sided ilia. There were no neurovascular injuries, acetabulum, or sciatic notch violations, and no screws loosened or fractured. Of interest, only one patient required off-set connectors to link the rods to the iliac screws.

Conclusions

Placement of long iliac screws under intraoperative fluoroscopy only was shown to be feasible, with a high accuracy rate and few complications, in this series of patients.

Long iliac screw fixation in a case of isthmic spondyloptosis

BACKGROUND

We report the case of a patient with a spondyloptosis who presented with progressive deformity and worsening neurological deficits. The patient had two previous lumbosacral instrumented fusions.

CASE DESCRIPTION

A salvage revision surgery was performed, in which long iliac screws along with anterior column support at L5-S1 were used to immobilize the lumbosacral junction. Two years after the procedure a solid fusion is seen along with marked neurological improvement.

CONCLUSIONS

Pelvic fixation using long iliac screws is a very useful technique that can be employed when revision surgery for high-grade spondylolisthesis is needed.

Management of infectious intracranial aneurysms in the pediatric population

INTRODUCTION

Infectious intracranial aneurysms (IIAs) account for approximately 15 % of all pediatric intracranial aneurysms. Histologically, they are pseudoaneurysms that develop in response to an inflammatory reaction within the adventitia and muscularis layers, ultimately resulting in disruption of both the internal elastic membrane and the intima. The majority of pediatric IIAs are located within the anterior circulation, and they can be multiple in 15-25 % of cases.

BACKGROUND

The most common presentation for an IIA is intracerebral and/or subarachnoid hemorrhage. In children with a known diagnosis of infective endocarditis who develop new neurological manifestations, it is imperative to exclude the existence of an IIA. The natural history of untreated infectious aneurysms is ominous; they demonstrate a high incidence of spontaneous rupture. High clinical suspicion, prompt diagnosis, and adequate treatment are of paramount importance to prevent devastating neurological consequences.

DISCUSSION

The prompt initiation of intravenous broad-spectrum antibiotics represents the mainstay of treatment. Three questions should guide the management of pediatric patients with IIAs: (a) aneurysm rupture status, (b) the presence of intraparenchymal hemorrhage or elevated intracranial pressure, and (c) relationship of the parent vessel to eloquent brain tissue. Those three questions should orient the treating physician into either antibiotic therapy alone or in combination with microsurgical or endovascular interventions. This review discusses important aspects of the epidemiology, the diagnosis, and the management of IIAs in the pediatric population.

Lumbopelvic fixation and sacral decompression for a U-shaped sacral fracture: case report

BACKGROUND: U-shaped sacral fractures are highly unstable, can cause significant neurological deficits, lead to progressive deformity and chronic pain if not treated appropriately. OBJECTIVE: To report a case of a U-shaped sacral fracture treated with lumbopelvic fixation and decompression of sacral roots in a 23-years-old man. METHOD: Decompression of the sacral roots combined with internal reduction and lumbopelvic fixation using iliac screws. RESULTS: Restitution of lumbosacropelvic stability and recovery of sphincter function. CONCLUSION: Lumbopelvic fixation is effective in restoring lumbosacralpelvic stability and allows full mobilization in the postoperative period. Good neurological recovery can be expected in the absence of discontinuity of the sacral roots.

C1 lateral mass screws for posterior segmental stabilization of the upper cervical spine and a new method of three-point rigid fixation of the C1-C2 complex

OBJECTIVE: To describe our experience with C1 lateral mass screws as part of a construct for C1-2 stabilization and report an alternate method of C1-C2 complex three-point fixation. METHOD: All patients that had at least one screw placed in the lateral mass of C1 as part of a construct for stabilization of the C1-C2 complex entered this study. In selected patients who had a higher chance of nonunion an alternate construct was used: transarticular C1-C2 screws combined with C1 lateral mass screws. RESULTS: Twenty-one C1 lateral mass screws were placed in 11 patients. In three patients the alternate construct was used. All patients had a demonstrable solid and stable fusion on follow-up. CONCLUSION: C1 lateral mass screws are safe and provide immediate stability. The use of C1-C2 transarticular screws combined with C1 lateral mass screws is a feasible and also an excellent alternative for a three-point fixation of the C1-C2 complex.

Cavernous malformations of the brainstem in infants. Report of two cases and review of the literature

Cavernous malformations of the brainstem (CMB) occur less commonly in children than in adults. Their appearance is even rarer in infants, with only five cases reported in the literature. The authors report two additional cases in which giant CMBs were diagnosed in two infants, one when the patient was 1 month old and the other when the patient was 15 months old. A median suboccipital approach in one patient and a pterional-orbitozygomatic approach in the other were used to obtain complete resection of the malformations. Excellent outcomes were achieved in both children. A review of the literature is also presented. It seems that CMBs in infants usually follow a progressive course of growth and associated neurological deterioration. Patients with symptomatic lesions abutting the pial surface should undergo surgical treatment with the goal of cure. An increase may be expected in the number of CMBs diagnosed in children as a result of regular screening of relatives with the familial form of the disease. Nevertheless, due to the small confines of the brainstem, incidental or asymptomatic CMB should still be extraordinary. In the case of such a rare occurrence, conservative treatment should be advocated.