A multicenter validation of the condylar–C2 sagittal vertical alignment in Chiari malformation type I: a study using the Park-Reeves Syringomyelia Research Consortium

2021 ◽  
pp. 1-7
Author(s):  
Vijay M. Ravindra ◽  
Rajiv R. Iyer ◽  
Alexander T. Yahanda ◽  
Robert J. Bollo ◽  
Huirong Zhu ◽  
...  
Keyword(s):  
Chiari Malformation ◽  
Intraclass Correlation ◽  
Misclassification Rate ◽  
Secondary Outcome ◽  
Posterior Fossa Decompression ◽  
Type I ◽  
Vertical Alignment ◽  
Disc Space ◽  
Chiari Malformation Type I ◽  
Research Consortium

OBJECTIVE The condylar–C2 sagittal vertical alignment (C-C2SVA) describes the relationship between the occipitoatlantal joint and C2 in patients with Chiari malformation type I (CM-I). It has been suggested that a C-C2SVA ≥ 5 mm is predictive of the need for occipitocervical fusion (OCF) or ventral brainstem decompression (VBD). The authors’ objective was to validate the predictive utility of the C-C2SVA by using a large, multicenter cohort of patients. METHODS This validation study used a cohort of patients derived from the Park-Reeves Syringomyelia Research Consortium; patients < 21 years old with CM-I and syringomyelia treated from June 2011 to May 2016 were identified. The primary outcome was the need for OCF and/or VBD. After patients who required OCF and/or VBD were identified, 10 age- and sex-matched controls served as comparisons for each OCF/VBD patient. The C-C2SVA (defined as the position of a plumb line from the midpoint of the O–C1 joint relative to the posterior aspect of the C2–3 disc space), pBC2 (a line perpendicular to a line from the basion to the posteroinferior aspect of the C2 body), and clival-axial angle (CXA) were measured on sagittal MRI. The secondary outcome was the need for ≥ 2 CM-related operations. RESULTS Of the 206 patients identified, 20 underwent OCF/VBD and 14 underwent repeat posterior fossa decompression. A C-C2SVA ≥ 5 mm was 100% sensitive and 86% specific for requiring OCF/VBD, with a 12.6% misclassification rate, whereas CXA < 125° was 55% sensitive and 99% specific, and pBC2 ≥ 9 was 20% sensitive and 88% specific. Kaplan-Meier analysis demonstrated that there was a significantly shorter time to second decompression in children with C-C2SVA ≥ 5 mm (p = 0.0039). The mean C-C2SVA was greater (6.13 ± 1.28 vs 3.13 ± 1.95 mm, p < 0.0001), CXA was lower (126° ± 15.4° vs 145° ± 10.7°, p < 0.05), and pBC2 was similar (7.65 ± 1.79 vs 7.02 ± 1.26 mm, p = 0.31) among those who underwent OCF/VBD versus decompression only. The intraclass correlation coefficient for the continuous measurement of C-C2SVA was 0.52; the kappa value was 0.47 for the binary categorization of C-C2SVA ≥ 5 mm. CONCLUSIONS These results validated the C-C2SVA using a large, multicenter, external cohort with 100% sensitivity, 86% specificity, and a 12.6% misclassification rate. A C-C2SVA ≥ 5 mm is highly predictive of the need for OCF/VBD in patients with CM-I. The authors recommend that this measurement be considered among the tools to identify the “high-risk” CM-I phenotype.

Extradural decompression versus duraplasty in Chiari malformation type I with syrinx: outcomes on scoliosis from the Park-Reeves Syringomyelia Research Consortium

2021 ◽  
pp. 1-9
Author(s):  
Brooke Sadler ◽  
Alex Skidmore ◽  
Jordan Gewirtz ◽  
Richard C. E. Anderson ◽  
Gabe Haller ◽  
...  
Keyword(s):  
Chiari Malformation ◽  
Foramen Magnum ◽  
Curve Progression ◽  
Posterior Fossa Decompression ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Curve Magnitude ◽  
Curve Stabilization ◽  
Research Consortium

OBJECTIVE Scoliosis is common in patients with Chiari malformation type I (CM-I)–associated syringomyelia. While it is known that treatment with posterior fossa decompression (PFD) may reduce the progression of scoliosis, it is unknown if decompression with duraplasty is superior to extradural decompression. METHODS A large multicenter retrospective and prospective registry of 1257 pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for patients with scoliosis who underwent PFD with or without duraplasty. RESULTS In total, 422 patients who underwent PFD had a clinical diagnosis of scoliosis. Of these patients, 346 underwent duraplasty, 51 received extradural decompression alone, and 25 were excluded because no data were available on the type of PFD. The mean clinical follow-up was 2.6 years. Overall, there was no difference in subsequent occurrence of fusion or proportion of patients with curve progression between those with and those without a duraplasty. However, after controlling for age, sex, preoperative curve magnitude, syrinx length, syrinx width, and holocord syrinx, extradural decompression was associated with curve progression > 10°, but not increased occurrence of fusion. Older age at PFD and larger preoperative curve magnitude were independently associated with subsequent occurrence of fusion. Greater syrinx reduction after PFD of either type was associated with decreased occurrence of fusion. CONCLUSIONS In patients with CM-I, syrinx, and scoliosis undergoing PFD, there was no difference in subsequent occurrence of surgical correction of scoliosis between those receiving a duraplasty and those with an extradural decompression. However, after controlling for preoperative factors including age, syrinx characteristics, and curve magnitude, patients treated with duraplasty were less likely to have curve progression than patients treated with extradural decompression. Further study is needed to evaluate the role of duraplasty in curve stabilization after PFD.

scholarly journals Factors associated with syrinx size in pediatric patients treated for Chiari malformation type I and syringomyelia: a study from the Park-Reeves Syringomyelia Research Consortium

2020 ◽  
Vol 25 (6) ◽  
pp. 629-639
Author(s):  
Andrew T. Hale ◽  
P. David Adelson ◽  
Gregory W. Albert ◽  
Philipp R. Aldana ◽  
Tord D. Alden ◽  
...  
Keyword(s):  
Chiari Malformation ◽  
Pediatric Patients ◽  
Posterior Fossa Decompression ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Factors Associated ◽  
Younger Age ◽  
Age At Surgery ◽  
Spinal Segments ◽  
Research Consortium

OBJECTIVEFactors associated with syrinx size in pediatric patients undergoing posterior fossa decompression (PFD) or PFD with duraplasty (PFDD) for Chiari malformation type I (CM-I) with syringomyelia (SM; CM-I+SM) are not well established.METHODSUsing the Park-Reeves Syringomyelia Research Consortium registry, the authors analyzed variables associated with syrinx radiological outcomes in patients (< 20 years old at the time of surgery) with CM-I+SM undergoing PFD or PFDD. Syrinx resolution was defined as an anteroposterior (AP) diameter of ≤ 2 mm or ≤ 3 mm or a reduction in AP diameter of ≥ 50%. Syrinx regression or progression was defined using 1) change in syrinx AP diameter (≥ 1 mm), or 2) change in syrinx length (craniocaudal, ≥ 1 vertebral level). Syrinx stability was defined as a < 1-mm change in syrinx AP diameter and no change in syrinx length.RESULTSThe authors identified 380 patients with CM-I+SM who underwent PFD or PFDD. Cox proportional hazards modeling revealed younger age at surgery and PFDD as being independently associated with syrinx resolution, defined as a ≤ 2-mm or ≤ 3-mm AP diameter or ≥ 50% reduction in AP diameter. Radiological syrinx resolution was associated with improvement in headache (p < 0.005) and neck pain (p < 0.011) after PFD or PFDD. Next, PFDD (p = 0.005), scoliosis (p = 0.007), and syrinx location across multiple spinal segments (p = 0.001) were associated with syrinx diameter regression, whereas increased preoperative frontal-occipital horn ratio (FOHR; p = 0.007) and syrinx location spanning multiple spinal segments (p = 0.04) were associated with syrinx length regression. Scoliosis (HR 0.38 [95% CI 0.16–0.91], p = 0.03) and smaller syrinx diameter (5.82 ± 3.38 vs 7.86 ± 3.05 mm; HR 0.60 [95% CI 0.34–1.03], p = 0.002) were associated with syrinx diameter stability, whereas shorter preoperative syrinx length (5.75 ± 4.01 vs 9.65 ± 4.31 levels; HR 0.21 [95% CI 0.12–0.38], p = 0.0001) and smaller pB-C2 distance (6.86 ± 1.27 vs 7.18 ± 1.38 mm; HR 1.44 [95% CI 1.02–2.05], p = 0.04) were associated with syrinx length stability. Finally, younger age at surgery (8.19 ± 5.02 vs 10.29 ± 4.25 years; HR 1.89 [95% CI 1.31–3.04], p = 0.01) was associated with syrinx diameter progression, whereas increased postoperative syrinx diameter (6.73 ± 3.64 vs 3.97 ± 3.07 mm; HR 3.10 [95% CI 1.67–5.76], p = 0.003), was associated with syrinx length progression. PFD versus PFDD was not associated with syrinx progression or reoperation rate.CONCLUSIONSThese data suggest that PFDD and age are independently associated with radiological syrinx improvement, although forthcoming results from the PFDD versus PFD randomized controlled trial (NCT02669836, clinicaltrials.gov) will best answer this question.

scholarly journals Syrinx resolution after posterior fossa decompression in patients with scoliosis secondary to Chiari malformation type I

2011 ◽  
Vol 21 (6) ◽  
pp. 1143-1150 ◽  
Author(s):  
Tao Wu ◽  
Zezhang Zhu ◽  
Jian Jiang ◽  
Xin Zheng ◽  
Xu Sun ◽  
...  
Keyword(s):  
Posterior Fossa ◽  
Chiari Malformation ◽  
Posterior Fossa Decompression ◽  
Type I ◽  
Chiari Malformation Type I

Comparison of posterior fossa decompression with and without duraplasty for the surgical treatment of Chiari malformation Type I in pediatric patients: a meta-analysis

2008 ◽  
Vol 2 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Susan R. Durham ◽  
Kristina Fjeld-Olenec
Keyword(s):  
Cerebrospinal Fluid ◽  
Surgical Treatment ◽  
Clinical Improvement ◽  
Posterior Fossa ◽  
Chiari Malformation ◽  
Meta Analysis ◽  
Posterior Fossa Decompression ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Patient Age

Object Surgery for Chiari malformation Type I (CM-I) is one of the most common neurosurgical procedures performed in children, although there is clearly no consensus among practitioners about which surgical method is preferred. The objective of this meta-analysis was to compare the outcome of posterior fossa decompression with duraplasty (PFDD) and posterior fossa decompression without duraplasty (PFD) for the treatment of CM-I in children. Methods The authors searched Medline–Ovid, The Cochrane Library, and the conference proceedings of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons (2000–2007) for studies meeting the following inclusion criteria: 1) surgical treatment of CM-I; 2) surgical techniques of PFD and PFDD being reported in a single cohort; and 3) patient age < 18 years. Results Five retrospective and 2 prospective cohort studies involving a total of 582 patients met the criteria for inclusion in the meta-analysis. Of the 582 patients, 316 were treated with PFDD and 266 were treated with PFD alone. Patient age ranged from 6 months to 18 years. Patients undergoing PFDD had a significantly lower reoperation rate (2.1 vs 12.6%, risk ratio [RR] 0.23, 95% confidence interval [CI] 0.08–0.69) and a higher rate of cerebrospinal fluid–related complications (18.5 vs 1.8%, RR 7.64, 95% CI 2.53–23.09) than those undergoing PFD. No significant differences in either clinical improvement (78.6 vs 64.6%, RR 1.23, 95% CI 0.95–1.59) or syringomyelia decrease (87.0 vs 56.3%, RR 1.43, 95% CI 0.91–2.25) were noted between PFDD and PFD. Conclusions Posterior fossa decompression with duraplasty is associated with a lower risk of reoperation than PFD but a greater risk for cerebrospinal fluid–related complications. There was no significant difference between the 2 operative techniques with respect to clinical improvement or decrease in syringomyelia.

Patients with Chiari malformation Type I presenting with acute neurological deficits: case series

2011 ◽  
Vol 7 (3) ◽  
pp. 244-247 ◽  
Author(s):  
Chester K. Yarbrough ◽  
Alexander K. Powers ◽  
Tae Sung Park ◽  
Jeffrey R. Leonard ◽  
David D. Limbrick ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Posterior Fossa ◽  
Neurological Deficit ◽  
Chiari Malformation ◽  
Acute Onset ◽  
Posterior Fossa Decompression ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Sensory Deficits ◽  
Operative Notes

Object A subset of patients with Chiari malformation Type I (CM-I) presented with acute onset of a neurological deficit. In this study the authors summarize their experience with these patients' clinical presentation, imaging results, timing of surgery, and outcome following decompression. Methods The authors reviewed clinical records, imaging studies, and operative notes from all patients undergoing posterior fossa decompression for CM-I at St. Louis Children's Hospital from 1990 to 2008. Of the 189 patients who underwent surgery, 6 were identified with the acute onset of a neurological deficit at presentation. Results All 6 children (age range 3–14 years, 3 boys and 3 girls) had either syringomyelia (5 patients) or T2 signal changes in the spinal cord (1 patient) and CM-I on initial MR imaging. Three patients presented after minor trauma (1 with paraparesis, 2 with sensory deficits). Three patients presented without a clear history of trauma (1 with abrupt onset of spontaneous dysphagia and ataxia, 2 with sensory deficits). Decompression was performed at a mean 7.7 ± 4.9 days after symptom onset (7.0 ± 1.6 days after neurosurgical evaluation). In 1 patient, symptoms had resolved by the time of surgery; in the remainder of the patients, clear improvements were noted within 2 weeks of surgery, with complete resolution of symptoms by 12 months postoperatively. Follow-up MR images were obtained in 4 patients, demonstrating improvement in the extent of the syrinx in each patient. Conclusions Children with CM-I and syringomyelia can develop acute spinal cord or bulbar deficits with relatively minor head or neck injuries. The prognosis for symptomatic improvement in the observed deficit is good, with each patient in our series showing resolution of deficits over time. However, based on this relatively limited experience, the authors suggest that patients who present with an acute neurological deficit and are found to have CM-I be managed with early posterior fossa decompression. Patients with CM-I and syringomyelia may be at higher risk of acute neurological deficit than those without a syrinx.

Complications following decompression of Chiari malformation Type I in children: dural graft or sealant?

2011 ◽  
Vol 8 (2) ◽  
pp. 177-183 ◽  
Author(s):  
Stephen R. Parker ◽  
Peggy Harris ◽  
Thomas J. Cummings ◽  
Timothy George ◽  
Herbert Fuchs ◽  
...  
Keyword(s):  
Aseptic Meningitis ◽  
Complication Rate ◽  
Chiari Malformation ◽  
Csf Leak ◽  
Posterior Fossa Decompression ◽  
Type I ◽  
Complication Rates ◽  
Chiari Malformation Type I ◽  
Dural Graft ◽  
Tissue Sealant

Object Posterior fossa decompression with duraplasty for Chiari malformation Type I (CM-I) is a common pediatric neurosurgery procedure. Published series report a complication rate ranging from 3% to 40% for this procedure. Historically, many dural substitutes have been used, including bovine grafts, human cadaveric pericardium, synthetic dura, and autologous pericranium. The authors hypothesized that a recently observed increase in complications was dependent on the graft used. Methods Between January 2004 and January 2008, 114 consecutive patients ≤ 18 years old underwent primary CM-I decompression using duraplasty. Records were retrospectively reviewed for short- and intermediate-term complications and operative technique, focusing on the choice of duraplasty graft with or without application of a tissue sealant. Results The average age of the patients was 8.6 years. The dural graft used was variable: 15 were treated with cadaveric pericardium, 12 with Durepair, and 87 with EnDura. Tisseel was used in 75 patients, DuraSeal in 12, and no tissue sealant was used in 27 patients. The overall complication rate was 21.1%. The most common complications included aseptic meningitis, symptomatic pseudomeningocele, or a CSF leak requiring reoperation. The overall complication rates were as follows: cadaveric pericardium 26.7%, Durepair 41.7%, and EnDura 17.2%; reoperation rates were 13%, 25%, and 8.1%, respectively. Prior to adopting a different graft product, the overall complication rate was 18.1%; following the change the rate increased to 35%. Complication rates for tissue sealants were 14.8% for no sealant, 18.7% for Tisseel, and 50% for DuraSeal. Nine patients were treated with the combination of Durepair and DuraSeal and this subgroup had a 56% complication rate. Conclusions Complication rates after CM-I decompression may be dependent on the dural graft with or without the addition of tissue sealant. The complication rate at the authors' institution approximately doubled following the adoption of a different graft product. Tissue sealants used in combination with a dural substitute to augment a duraplasty may increase the risk of aseptic meningitis and/or CSF leak. The mechanism of the apparent increased inflammation with this combination remains under investigation.

scholarly journals External validation of the Chicago Chiari Outcome Scale

2014 ◽  
Vol 13 (6) ◽  
pp. 679-684 ◽  
Author(s):  
Chester K. Yarbrough ◽  
Jacob K. Greenberg ◽  
Matthew D. Smyth ◽  
Jeffrey R. Leonard ◽  
Tae Sung Park ◽  
...  
Keyword(s):  
Interrater Reliability ◽  
Subjective Evaluation ◽  
External Validation ◽  
Intraclass Correlation ◽  
Predictive Ability ◽  
Posterior Fossa Decompression ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Improved Outcomes

Object Historically, assessment of clinical outcomes following surgical management of Chiari malformation Type I (CM-I) has been challenging due to the lack of a validated instrument for widespread use. The Chicago Chiari Outcome Scale (CCOS) is a novel system intended to provide a less subjective evaluation of outcomes for patients with CM-I. The goal of this study was to externally validate the performance of the CCOS. Methods Patients undergoing surgery for CM-I between 2001 and 2012 were reviewed (n = 292). Inclusion criteria for this study were as follows: 1) patients receiving primary posterior fossa decompression; 2) at least 5.5 months of postoperative clinical follow-up; and 3) patients ≤ 18 years of age at the time of surgery. Outcomes were evaluated using the CCOS, along with a “gestalt” impression of whether patients experienced significant improvement after surgery. A subgroup of 118 consecutive patients undergoing operations between 2008 and 2010 was selected for analysis of interrater reliability (n = 73 meeting inclusion/exclusion criteria). In this subgroup, gestalt and CCOS scores were independently determined by 2 reviewers, and interrater reliability was assessed using the intraclass correlation coefficient (ICC) and kappa (κ) statistic. Results The median CCOS score was 14, and 67% of patients had improved gestalt scores after surgery. Overall, the CCOS was effective at identifying patients with improved outcome after surgery (area under curve = 0.951). The interrater reliability of the CCOS (ICC = 0.71) was high, although the reliability of the component scores ranged from poor to good (ICC 0.23–0.89). The functionality subscore demonstrated a low ICC and did not add to the predictive ability of the logistic regression model (likelihood ratio = 1.8, p = 0.18). When analyzing gestalt outcome, there was moderate agreement between raters (κ = 0.56). Conclusions In this external validation study, the CCOS was effective at identifying patients with improved outcomes and proved more reliable than the authors' gestalt impression of outcome. However, certain component subscores (functionality and nonpain symptoms) were found to be less reliable, and may benefit from further definition in score assignment. In particular, the functionality subscore does not add to the predictive ability of the CCOS, and may be unnecessary. Overall, the authors found the CCOS to be an improvement over the previously used assessment of outcome at their institution.

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