Efficacy of Posterior Fossa Decompression with Duraplasty for Patients with Chiari Malformation Type I: A Systematic Review and Meta-Analysis

doi:10.1016/j.wneu.2018.02.092

World Neurosurgery

Volume 113, May 2018, Pages 357-365.e1

https://doi.org/10.1016/j.wneu.2018.02.092 Get rights and content

Highlights

•
The decrease in syringomyelia was better for patients in the PFDD group than for patients in the PFD group.
•
No significant difference was found in clinical improvement and reoperation rate between the 2 groups.
•
Further studies with a larger data set are required to validate these findings.

Objective

To quantitatively assess and compare the effectiveness and safety of posterior fossa decompression with duraplasty (PFDD) and posterior fossa decompression (PFD) in treating patients with Chiari malformation type I.

Methods

PubMed, Embase, and Cochrane Library were searched through May 2017. Fourteen cohort studies comprising 3666 patients with Chiari malformation type I were included. Studies were pooled, and the relative risk (RR) and corresponding 95% confidence interval (CI) were calculated.

Results

The decrease in syringomyelia was better in patients in the PFDD group than in patients in the PFD group (RR = 1.57, 95% CI = 1.07–2.32, P_{heterogeneity} = 0.042, I² = 56.6%). The incidence of cerebrospinal fluid leak (RR = 5.23, 95% CI = 2.61–10.51, P_{heterogeneity} = 0.830, I² = 0%) and aseptic meningitis (RR = 4.02, 95% CI = 1.46–11.03, P_{heterogeneity} = 0.960, I² = 0%) significantly increased among patients in the PFDD group compared with patients in the PFD group. When stratifying by age, a significantly reduced risk in the reoperation rate was observed in the adult group. However, the clinical improvement and the incidence of wound infection were not significantly different between the 2 groups.

Conclusions

This study confirmed that the decrease in syringomyelia was better for patients treated with PFDD than for patients treated with PFD alone. However, no significant difference was found in the clinical improvement and the reoperation rate between the 2 groups.

Introduction

Chiari malformation type I (CMI) is a congenital neurologic disorder with sporadic or familial occurrence, in which the cerebellum (or, more specifically, the cerebellar tonsils) descends out of the skull into the spinal area. This results in compression of parts of the brain and spinal cord and disrupts the normal flow of cerebrospinal fluid (CSF). Patients with CMI typically present with either brainstem compression or syringomyelia.1, 2 Although many theories have increased our knowledge of Chiari malformation, the exact pathogenesis is unknown.³

The clinical presentation of CMI is thought to be associated with CSF disturbances at the craniovertebral junction or with compression of neural structures. Accordingly, surgical treatment of CMI aims to expand the posterior cranial fossa.⁴ Although many surgical procedures for Chiari malformation have been used in clinical practice, controversy remains. Two main types of surgical modalities are available for treating CMI. One is posterior fossa decompression (PFD) or posterior fossa decompression with duraplasty (PFDD), and the other is reduction of the syrinx cavity using different types of shunt procedures.3, 5 PFD is the primary surgical method for treating CMI because of the low risk of iatrogenic spinal cord injury in shunt procedures.5, 6, 7, 8

Many studies have been published concerning PFDD and PFD as treatment for CMI.1, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 However, whether duraplasty should be performed during PFD remains controversial. Therefore, we conducted a systematic review and meta-analysis to assess the clinical advantages of the 2 methods for treating CMI.

Section snippets

Materials and Methods

The present meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.²²

Characteristics of the Studies

As demonstrated in Figure 1, 491 articles were identified, 452 of which were determined to be irrelevant based on the review of titles and abstracts. Thus, 30 full-text articles was assessed for eligibility. Of these 30 articles, 16 were excluded because they did not meet the inclusion criteria (7 without appropriate comparison and 9 without usable data). Fourteen articles fulfilled the inclusion criteria and were enrolled. The 14 retrieved articles comprised 3666 participants, 1631 patients in

Discussion

Meta-analysis is a potentially powerful tool to resolve the discrepancies across individual studies by integrating the results of previous reports.²⁶ In this study, a meta-analysis was performed comparing PFDD and PFD alone in patients with CMI. The meta-analysis showed that the decrease in syringomyelia was better for patients in the PFDD group than for patients in the PFD group (RR = 1.57, 95% CI = 1.07–2.32, P_{heterogeneity} = 0.042, I² = 56.6%). The incidence of CSF leak (RR = 5.23, 95%

Conclusions

Despite the limitations of this meta-analysis, it confirmed that the decrease in syringomyelia was better for patients treated with PFDD than for patients treated with PFD alone. However, no significant difference was found in the clinical improvement and the reoperation rate between the 2 groups. Further studies with a larger data set and well-designed models are required to validate the findings.

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Cited by (57)

Foramen Magnum Decompression for Chiari Malformation Type 1: Is There a Superior Surgical Technique?
2023, World Neurosurgery
Foramen magnum decompression is a common operation used to treat Chiari malformation. There are different surgical techniques; however, some are anecdotally more effective than others. Our aim was to determine whether there is a superior technique in relation to revision rates, presence of persistent postoperative headache and nausea, and syrinx reduction.
This was a retrospective analysis of foramen magnum decompressions performed between 2012 and 2017 for Chiari 1 in a single institution. Three types of operations were performed: 1) bony decompression alone; 2) bony decompression with durotomy and dura left open; 3) bony decompression with opening of dura and duraplasty. We compared postoperative symptoms and revision rates between these 3 operations.
In 168 patients, 185 foramen magnum decompressions were performed. Among the 168 primary operations, in 66 the dura was not opened, in 86 the dura was opened without a duraplasty, and in 16 a duraplasty was performed. Of 185 operations, 17 were revision surgery. For primary procedures, the revision rates were 12 (18%) where the dura was not opened, 4 (5%) where the dura was left open, and 1 (6%) when duraplasty was performed. Severe postoperative headache and nausea occurred in 2 (3%) patients where the dura was not opened, 4 (25%) patients after primary duraplasty, and 64 (74%) patients after primary durotomy.
In this study, rate of revision surgery was highest in patients who had bony decompression without dural opening. Rate of postoperative headache and nausea was highest in the durotomy group. Overall duraplasty had the best results.
Comparative Assessment of Three Posterior Fossa Decompression Techniques and Evaluation of the Evidence Supporting the Efficacy of Syrinx Shunting and Filum Terminale Sectioning in Chiari Malformation Type I. A Systematic Review and Network Meta-Analysis
2021, World Neurosurgery
Citation Excerpt :
The reoperation risk did not differ among all 3 techniques. Most meta-analyses are in step with that statement.3,9,29 Lin et al.30 postulate the superiority of PFDD over PFD regarding recurrence after initial surgery in patients with syringomyelia-Chiari complex because duraplasty leads to enlargement of the intradural space.
This study aimed to compare the effectiveness of posterior fossa decompression (PFD), posterior fossa decompression with duraplasty (PFDD), and posterior fossa decompression with resection of tonsils (PFDRT) in Chiari malformation type I (CMI). Furthermore, we aimed to evaluate the evidence supporting the efficacy of filum terminale sectioning (FTS), syringosubarachnoid shunting (SSS), and syringoperitoneal shunting (SPS) in CMI.
PubMed, Cochrane, and Embase databases were screened for English-language studies published from inception until August 11, 2020. A total of 3593 studies were identified through the searching process. Fifteen cohort studies were included in the systematic review and network meta-analysis.
No studies concerning FTS, SSS, and SPS were found eligible. Therefore, only PFD, PFDD, and PFDRT were compared. PFDD showed significantly higher incidence of complications (relative risk [RR], 3.79; 95% confidence interval [CI], 2.54–5.64) cerebrospinal fluid leak (RR, 9.74; 95% CI, 2.33–40.78) and neurologic deficit (RR, 8.76; 95% CI, 2.08–36.90) than did PFD. Both PFDD and PFDRT achieved higher syringomyelia improvement (RR, 1.23, 95% CI, 1.09–1.39 and RR, 1.32, 95% CI, 1.15–1.51, respectively) and greater clinical improvement (RR, 1.24, 95% CI, 1.10–1.39 and RR, 1.24, 95% CI, 1.08–1.44, respectively) than did PFD. No differences were found between PFDD and PFDRT.
PFDD and PFDRT are superior to PFD, especially in patients with syringomyelia-Chiari complex, because of greater syringomyelia reduction and better clinical improvement. However, PFDD and PFDRT can be considered equally efficient. There is no evidence pleading in favor of SFT, SSS, and SPS over any PFD technique.
Inpatient outcomes of posterior fossa decompression with or without duraplasty for Chiari malformation type I
2021, Clinical Neurology and Neurosurgery
Chiari malformation type 1 (CM-1) is a congenital neurologic condition in which the cerebellar tonsils herniate below the foramen magnum, resulting in symptoms such as headache and neck pain. Two common surgical treatment approaches are posterior fossa decompression with (PFDD) and without duraplasty (PFD). Previous single-center studies have demonstrated increased neurologic complications after PFDD compared to PFD. The goal of this study is to determine differences in inpatient complications and hospitalization data among patients treated with these surgical techniques using a nationwide sample.
The National Inpatient Sample (NIS) was queried for years 2012–2015 for all patients with a primary diagnosis of CM-1 who underwent PFD or PFDD. Differences in baseline demographics and comorbidities were accounted for in subsequent analysis using propensity score matching. Hospitalization measures and inpatient complications of the two cohorts were compared using Chi-squared tests and t-tests when appropriate.
A total of 2395 patients with CM-1 were included in this study, with 750 (31.3%) undergoing PFD and 1645 (68.7%) undergoing PFDD. PFDD was associated with higher total hospital costs than PFD. There were no significant differences in other hospitalization or discharge data, non-neurologic complications, or CNS complications (CSF leak, pseudomeningocele, abscess, meningitis, stroke) between the two surgical groups.
This study represents the largest national analysis to date of adult CM-1 patients undergoing PFD or PFDD. Our findings suggest that whether the decision is made to perform the less invasive PFD or more invasive PFDD, inpatient complications and hospitalization data will not significantly differ.
Long-term outcome of operated Chiari I patients between 2005 and 2020 in Eastern Finland
2024, Acta Neurochirurgica
Duraplasty using a combination of a pedicled dural flap and collagen matrix in posterior fossa decompression for pediatric Chiari malformation type 1 with syrinx
2024, Acta Neurochirurgica
Predictors of reoperation for spinal disorders in Chiari malformation patients with prior surgical decompression
2023, Journal of Craniovertebral Junction and Spine

View all citing articles on Scopus

: Conflict of interest statement: This work was supported by the National Natural Science Foundation of China (Grant No. 81102552, 81703978), International Science and Technology cooperation project, Shanxi Province of China (Grant No. 2014081049-4, 201703D421016), Research Project Supported by Shanxi Scholarship Council of China (Grant No. 2017-129), Returned Chinese Scholars Technology Activities Preferred Project, Shanxi Province of China (Grant No. 2017-19), and Great Science and Technology Innovation Team Project, Shanxi University of Traditional Chinese Medicine (Grant No. 20150401).

: Zhi Chai and Xiaoming Xue are co–first authors.

: Supplementary digital content available online.

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Literature ReviewEfficacy of Posterior Fossa Decompression with Duraplasty for Patients with Chiari Malformation Type I: A Systematic Review and Meta-Analysis

Highlights

Objective

Methods

Results

Conclusions

Introduction

Section snippets

Materials and Methods

Characteristics of the Studies

Discussion

Conclusions

World Neurosurg

Clin Neurol Neurosurg

Clin Neurol Neurosurg

World Neurosurg

The evaluation of surgical treatment options in the Chiari malformation type I

Turk Neurosurg

Chiari 1 malformations: an Indian hospital experience

Singapore Med J

Cerebellar tonsillectomy with suboccipital decompression and duraplasty by small incision for Chiari I malformation (with syringomyelia): long term follow-up of 76 surgically treated cases

Turk Neurosurg

Relevance of surgical strategies for the management of pediatric Chiari type I malformation

Childs Nerv Syst

Comparison of the surgical results for foramen magnum decompression with and without duraplasty in Chiari malformation type 1

Turk Neurosurg

Surgical indication and results of foramen magnum decompression versus syringosubarachnoid shunting for syringomyelia associated with Chiari I malformation

Neurosurgery

Posterior fossa decompression with tonsillectomy in 104 cases of basilar impression, Chiari malformation and/or syringomyelia

Arq Neuropsiquiatr

“Conservative” cranio-cervical decompression in the treatment of syringomyelia-Chiari I complex. A prospective study of 20 adult cases

Spine (Phila Pa 1976)

Effects of posterior fossa decompression with and without duraplasty on Chiari malformation-associated hydromyelia

Neurosurgery

Dura-splitting decompression of the craniocervical junction: reduced operative time, hospital stay, and cost with equivalent early outcome

J Neurosurg

Surgical results of posterior fossa decompression for patients with Chiari I malformation

Childs Nerv Syst

Intraoperative ultrasonography used to determine the extent of surgery necessary during posterior fossa decompression in children with Chiari malformation type I

J Neurosurg

Intraoperative ultrasonography as a guide to patient selection for duraplasty after suboccipital decompression in children with Chiari malformation type I

J Neurosurg Pediatr

Literature Review
Efficacy of Posterior Fossa Decompression with Duraplasty for Patients with Chiari Malformation Type I: A Systematic Review and Meta-Analysis