Dura Management Strategies in the Surgical Treatment of Adult Chiari Type I Malformation: A Retrospective, Multicenter, Population-Based Parallel Cohort Case Series

Difference in clinical presentation and surgical outcomes in pediatric and adult patients with Chiari malformation type 1: a single center retrospective study

INTRODUCTION

Chiari malformation type 1 (CM1) is a common congenital disorder affecting both children and adults. Although pediatric and adult CM1 patients share many characteristics, the differences between the groups are not fully described.

METHOD

A comparative analysis was made of two previously defined cohorts of adult and pediatric non-syndromic CM1, surgically treated at the study center. Clinical outcomes were assessed using the Chicago Chiari outcome scale (CCOS) and radiological outcomes were measured as change in cerebellar tonsil and syringomyelia status.

RESULTS

A total of 209 patients (73 pediatric, 136 adults) were included, with median ages of 11 and 33 years, respectively. The proportion of female patients (62% vs 78%) was higher in the adult population (p = 0.012). Headache (p = 0.007), neck pain (p = 0.000), vertigo (p = 0.007), and sensory symptoms (p = 0.000) were more common in adults, while scoliosis (p = 0.000) and sleep apnea (p = 0.015) were more common in the pediatric population. Preoperative imaging findings did not differ significantly. After posterior fossa decompression, both groups scored a median CCOS of 15 at early follow-up (3 vs 4 months), though the pediatric population had a more favorable distribution of CCOS scores (p = 0.003). Postoperatively, syringomyelia status did not differ significantly between groups, but cerebellar tonsil status improved more frequently in adults (64% vs 88%, p = 0.000).

CONCLUSION

This study demonstrates that while headache is the most common presenting symptom in both pediatric and adult CM1 patients, pediatric patients are more likely to present with scoliosis and sleep apnea. In contrast adult patients more frequently experience headache, neck pain, vertigo, and sensory symptoms. There were no differences in other preoperative imaging variables and outcomes were favorable for most patients in both groups.

Clinical efficacy of surgery for patients with Chiari malformation type I with syringomyelia: posterior fossa decompression versus posterior fossa decompression with resection of tonsils

Background

The optimal surgical approach for treating Chiari malformation type I (CM-I) with syringomyelia remains a topic of debate. Key areas of controversy include the extent of decompressive craniectomy, the necessity of subarachnoid exploration, and whether to excise the herniated tonsils. In this study, we present our perspectives on these contentious issues through a retrospective analysis of the clinical efficacy of posterior fossa decompression with resection of tonsils (PFDRT) compared to posterior fossa decompression (PFD).

Methods

We conducted a retrospective analysis of clinical data from 162 patients diagnosed with CM-I and syringomyelia who underwent surgical intervention at the Affiliated Hospital of Xuzhou Medical University between January 2017 and December 2022. Among these, 58 patients underwent PFD, while 104 received PFDRT. The efficacy of the treatments was evaluated using the Chicago Chiari Deformity Prognosis Scale (CCOS) at 6 months post-surgery, with scores ranging from 13 to 16 indicating a favorable prognosis. Furthermore, the improvement of syringomyelia was assessed through magnetic resonance imaging (MRI) at the six-month follow-up.

Results

Six months post-surgery, according to the Chiari Clinical Outcome Scale (CCOS) score, the improved rates for the PFD and PFDRT groups were 56.9 and 78.8%, respectively. Additionally, the recovery rates for syringomyelia in these groups were 55.2 and 76%, respectively. Statistically significant differences were observed in both the rates of favorable prognosis and syringomyelic improvement between the two groups (p < 0.05). The incidence of complications, including fever, cerebrospinal fluid leakage, intracranial infection, and incision infection, did not differ significantly between the groups (p > 0.05).

Conclusion

Our findings indicate that PFDRT yields superior outcomes in syringomyelia improvement and favorable prognoses compared to PFD, while maintaining comparable postoperative complication rates.

Long-term outcomes following posterior fossa decompression in pediatric patients with Chiari malformation type 1, a population-based cohort study

OBJECTIVE

Posterior fossa decompression for Chiari malformation type I (Chiari 1) is effective and associated with a low risk of complication. However, up to 20% of patients may experience continued deficits or recurring symptoms after surgical intervention. For pediatric patients, there are no established tools to predict outcomes, and the risk factors for unfavorable postoperative outcomes are poorly understood. Hence, our aim was to investigate baseline data and early postoperative predictors of poor outcomes as determined by the Chicago Chiari outcome scale (CCOS).

METHODS

All pediatric patients (< 18 years) receiving a posterior fossa decompression for Chiari 1 between the years of 2005 and 2020 at the study center were eligible for inclusion. Patients with congenital anomalies were excluded.

RESULTS

Seventy-one pediatric patients with a median age of 9 years were included. Most patients (58%) were females. Chiari 1 was associated with syringomyelia (51%), scoliosis (37%), and hydrocephalus (7%). Perioperative complications occurred in 13 patients (18%) of which two required additional procedures under general anesthesia. On multivariable proportional odds logistic regression, motor deficits (OR: 0.09; CI95%: [0.01-0.62]; p = 0.015), and surgical complications (OR: 0.16; CI95%: [0.41-0.66]; p = 0.011) were significant predictors of worse outcomes. The presence of syringomyelia was identified as a predictor of better outcomes (OR: 4.42 CI95% [1.02-19.35]; p = 0.048). A persistent hydrocephalus during the early postoperative period after posterior fossa decompression was a strong predictor of worse long-term CCOS (OR: 0.026; CI95%: [0.002-0.328]; p = 0.005).

CONCLUSION

Results from this study indicate that the existence of motor deficits and syringomyelia prior to surgery, and surgical complications and persistent hydrocephalus despite posterior fossa decompression, were useful predictors of long-term outcome.

How I do it - The "drum skin" duraplasty technique after foramen magnum decompression for Chiari malformations

BACKGROUND

Chiari malformations are a spectrum of posterior cranial fossa anomalies characterized by herniation of the cerebellar tonsils through the foramen magnum. Surgery is the treatment of choice for selected patients with good postoperative outcomes.

METHODS

We describe foramen magnum decompression (FMD) with dural opening and a "drum skin" duraplasty technique.

CONCLUSIONS

In our experience, FMD with "drum skin" duraplasty is a safe and effective procedure, reducing the risk of CSF leakage and arachnoidal adhesions and yielding better long-term clinical and radiological outcomes than other traditional techniques.

Predictors of reoperation for spinal disorders in Chiari malformation patients with prior surgical decompression

Background

Chiari malformation (CM) is a cluster of related developmental anomalies of the posterior fossa ranging from asymptomatic to fatal. Cranial and spinal decompression can help alleviate symptoms of increased cerebrospinal fluid pressure and correct spinal deformity. As surgical intervention for CM increases in frequency, understanding predictors of reoperation may help optimize neurosurgical planning.

Materials and Methods

This was a retrospective analysis of the prospectively collected Healthcare Cost and Utilization Project's California State Inpatient Database years 2004-2011. Chiari malformation Types 1-4 (queried with ICD-9 CM codes) with associated spinal pathologies undergoing stand-alone spinal decompression (queried with ICD-9 CM procedure codes) were included. Cranial decompressions were excluded.

Results

One thousand four hundred and forty-six patients (29.28 years, 55.6% of females) were included. Fifty-eight patients (4.01%) required reoperation (67 reoperations). Patients aged 40-50 years had the most reoperations (11); however, patients aged 15-20 years had a significantly higher reoperation rate than all other groups (15.5% vs. 8.2%, P = 0.048). Female gender was significantly associated with reoperation (67.2% vs. 55.6%, P = 0.006). Medical comorbidities associated with reoperation included chronic lung disease (19% vs. 6.9%, P < 0.001), iron deficiency anemia (10.3% vs. 4.1%, P = 0.024), and renal failure (3.4% vs. 0.9%, P = 0.05). Associated significant cluster anomalies included spina bifida (48.3% vs. 34.8%, P = 0.035), tethered cord syndrome (6.9% vs. 2.1%, P = 0.015), syringomyelia (12.1% vs. 5.9%, P = 0.054), hydrocephalus (37.9% vs. 17.7%, P < 0.001), scoliosis (13.8% vs. 6.4%, P = 0.028), and ventricular septal defect (6.9% vs. 2.3%, P = 0.026).

Conclusions

Multiple medical and CM-specific comorbidities were associated with reoperation. Addressing them, where possible, may aid in improving CM surgery outcomes.

Post-Operative Complications after Foramen Magnum Decompression with Duraplasty Using Different Graft Materials in Adults Patients with Chiari I Malformation: A Systematic Review and Meta-Analysis

Despite extensive investigations, the choice of graft material for reconstructive duraplasty after foramen magnum decompression for Chiari type I malformation (CMI) is still a topic of discussion. The authors performed a systematic review and meta-analysis of the literature examining the post-operative complications in adult patients with CMI after foramen magnum decompression and duraplasty (FMDD) using different graft materials. Our systematic review included 23 studies with a total of 1563 patients with CMI who underwent FMDD with different dural substitutes. The most common complications were pseudomeningocele (2.7%, 95% CI 1.5-3.9%, p < 0.01, I² = 69%) and CSF leak (2%, 95% CI 1-2.9%, p < 0,01, I² = 43%). The revision surgery rate was 3% (95% CI 1.8-4.2%, p < 0.01, I² = 54%). A lower rate of pseudomeningocele was observed with autologous duraplasty when compared with synthetic duraplasty (0.7% [95% CI 0-1.3%] vs. 5.3% [95% CI 2.1-8.4%] p < 0.01). The rate of CSF leak and revision surgery was lower after autologous duraplasty than after non-autologous dural graft (1.8% [95% CI 0.5-3.1%] vs. 5.3% [95% CI 1.6-9%], p < 0.01 and 0.8% [95% CI 0.1-1.6%] vs. 4.9% [95% CI 2.6-7.2%] p < 0.01, respectively). Autologous duraplasty is associated with a lower rate of post-operative pseudomeningocele and reoperation. This information should be considered when planning duraplasty after foramen magnum decompression in patients with CMI.