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

Long-term outcome of operated Chiari I patients between 2005 and 2020 in Eastern Finland

PURPOSE

The purpose of our study was to examine the long-term outcomes of operated Chiari malformation type 1 (CM1) patients and evaluate whether different duraplasty techniques affected outcome after surgery in Kuopio University Hospital catchment area.

METHODS

In this retrospective study, a total of 93 patients were diagnosed with CM1 and underwent posterior fossa decompression surgery with or without duraplasty between 2005 and 2020. All patients' medical records were examined for baseline characteristics, surgical details, and long-term follow-up data after operation.

RESULTS

The mean age of CM1 patients was 25.9 years (SD 19.2 years), with female preponderance 69/93 (73.4%). The mean clinical follow-up time was 26.5 months (SD 33.5 months). The most common presenting symptoms were headache, symptoms of extremities, and paresthesia. Posterior fossa decompression with duraplasty was performed in 87 (93.5%) patients and bony decompression in 6 (6.5%) patients. After surgery, preoperative symptoms alleviated in 84.9% (79/93) and the postoperative syringomyelia regression rate was 89.2% (33/37) of all patients. The postoperative complication rate was 34.4% (32/93), with aseptic meningitis being the most common, 25.8% (24/93). Revision surgery was required in 14% (13/93) of patients. No significant correlation between postoperative outcome and extent of dural decompression, or type of duraplasty performed was found.

CONCLUSION

This is the largest reported series of surgically treated CM1 patients in Finland. Posterior fossa decompression is an effective procedure for CM1 symptomology. Duraplasty technique had no significant difference in complication rate or long-term 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.

Transient meningism in children after non-autologous duraplasty for Chiari Malformation surgery: A case series

BACKGROUND

Increasing the posterior fossa volume is the mainstay of treatment for Chiari type 1 Malformation (C1M) and type 1.5 (C1.5M). Different options to restore CSF flow have been described but no consensus has been reached yet. Bony decompression of posterior cranial fossa with dural opening provides good results but at the price of complications such as pseudomeningocele and aseptic meningitis. A single center retrospective analysis was conducted to find any relationships between outcome and perioperative factors. As a second goal a specific analysis was conducted on the complications and their hypothetical causes.

METHODS

All the pediatric patients who underwent to posterior fossa bony decompression and dural opening for C1M or C1.5M in the period 2008-2020 were included in the study. A minimum period of three-months follow-up was considered among the inclusion criteria.

RESULTS

A population of fifty-three consecutive patients was collected. Pseudomeningocele and a mild meningeal irritation resulted the most frequent complications. Considering preoperative and intraoperative factors, the type of dural graft showed a relatively strong correlation (P<.01) with pseudomeningocele appearance and the development of meningism. In the latter case, a short course of steroids was the only treatment required to control symptoms.

CONCLUSIONS

Different factors could influence the outcome in Chiari Malformation surgery and eventually the development of complications. An adequate dural graft selection is of paramount importance when a dural opening for posterior fossa augmentation is planned. In case of mild meningeal irritation, a trial with short course steroids could avoid revision surgery.

Above-The-Hairline Suboccipital Transverse Approach for the Treatment of Chiari I Malformation

BACKGROUND

Chiari I malformation is a common pediatric neurosurgical disorder with an established treatment paradigm. Posterior fossa decompression and duraplasty (PFDD) is associated with symptom improvement but it carries postoperative risk, particularly cerebrospinal fluid (CSF) leak and wound complications. In addition, the cosmetic outcomes of PFDD have been overlooked in the literature.

OBJECTIVE

To describe a novel approach for PFDD in which the transverse surgical incision is completely hidden above the hairline and to report early outcomes in a prospective patient cohort.

METHODS

Clinical and cosmetic outcomes were recorded for 15 consecutive pediatric patients who underwent PFDD for Chiari I malformation via the above-the-hairline transverse suboccipital approach.

RESULTS

The median clinical follow-up time was 6 months (range 1-12 months), and the majority of patients experienced significant improvement of their preoperative symptoms. Three patients (20%) experienced complications associated with surgery, which included injury to the greater occipital nerve, CSF hypotension and subfascial pseudomeningocele, and superficial wound dehiscence that resolved spontaneously with oral antibiotics. Zero patients (0%) returned to the operating room for persistent CSF leak, deep wound infection, or revision decompression. An excellent cosmetic outcome was achieved in 12 patients (80%). No patient had a poor cosmetic outcome.

CONCLUSION

The above-the-hairline transverse suboccipital approach for PFDD in patients with Chiari I malformation offers favorable cosmetic outcomes and fascial closure while permitting adequate decompression.

Trends in CSF Leakage Associated with Duraplasty in Infratentorial Procedures over the Last 20 Years: A Systematic Review

Cerebrospinal fluid (CSF) leakage is a common postoperative complication of neurosurgical procedures, with iatrogenic causes accounting for 16% of CSF leakages. This complication increases healthcare costs and patient morbidity. The focus of this review is to analyze the rates of CSF leakage of some of the most commonly used xenogeneic and synthetic dural substitutes following surgeries in the infratentorial region of the brain where surgical repair can be most challenging. A systematic literature search was conducted using studies detailing duraplasty procedures performed with nonautologous grafts in the infratentorial region in PubMed. Studies were identified using the following search terms: "posterior fossa" or "infratentorial" were used in combination with "CSF leak," "CSF leakage," "cerebrospinal fluid leakage," "duraplasty" or "dura graft." The outcome of interest was a measure of the prevalence of CSF leakage rates following posterior fossa neurosurgery. Studies that contributed data to this review were published between 2006 and 2021. The dural graft materials utilized included: bovine collagen, acellular dermis, equine collagen, bovine pericardium, collagen matrix, and expanded polytetrafluoroethylene (ePTFE). The number of subjects in studies on each of these grafts ranged from 6 to 225. CSF leak rates ranged from 0% to 25% with the predominance of studies reporting between 3% and 15%. The studies that utilize bovine collagen, equine collagen, and acellular dermis reported higher CSF leakage rates; whereas studies that utilized ePTFE, bovine pericardium, and collagen matrix reported lower CSF leakage rates. Due to the heterogeneity of methodologies used across these studies, it is difficult to draw a direct correlation between the dural patch products used and CSF leaks. Larger prospective controlled studies that evaluate various products in a head-to-head fashion, using the same methods and animal models, are needed to conclude the relative efficacy of these dural patch products.

Association between synthetic sealants and increased complication rates in posterior fossa decompression with duraplasty for Chiari malformations regardless of graft type

OBJECTIVE

Dural sealants are commonly used in posterior fossa decompression with duraplasty (PFDD) for Chiari malformation type I (CMI). Prior evidence suggests that combining certain sealants with some graft material is associated with an increased rate of complications. In 2018, the authors noted an increased rate of symptomatic pseudomeningocele and aseptic meningitis after PFDD in CMI patients. The authors utilized retrospective and prospective analyses to test the hypothesis that complication rates increase with the use or combination of certain sealants and grafts.

METHODS

The analysis was split into 2 periods. The authors retrospectively reviewed patients who underwent PFDD for CMI at their center between August 12, 2011, and December 31, 2018. The authors then eliminated use of DuraSeal on the basis of the retrospective analysis and prospectively examined complication rates from January 1, 2019, to August 4, 2021. The authors defined a complication as symptomatic pseudomeningocele, bacterial or aseptic meningitis, cerebrospinal fluid leak, subdural hygroma, hydrocephalus, surgical site infection, or wound dehiscence.

RESULTS

From 2011 to 2018, complications occurred in 24.5% of 110 patients. Sealant choice was correlated with complication rates: no sealant (0%), Tisseel (6%), and DuraSeal (15.3%) (p < 0.001). No difference in complication rate was noted on the basis of choice of graft material (p = 0.844). After eliminating DuraSeal, the authors followed 40 patients who underwent PFDD after 2018. The complication rate decreased to 12.5%. All complications after 2018 were associated with Tisseel.

CONCLUSIONS

At the authors' single center, use of sealants in PFDD surgery for CMI, especially DuraSeal, was correlated with a higher complication rate. Eliminating DuraSeal led to a significant decrease in the rate of symptomatic pseudomeningocele and aseptic meningitis.

Patient and operative factors associated with unanticipated intensive care admission and outcomes following posterior fossa decompressions in children: A retrospective study

INTRODUCTION

Posterior fossa decompression for Chiari I Malformation is a common pediatric neurosurgical procedure. We sought to identify the impact of anesthesia-related intraoperative complications on unanticipated admission to the intensive care unit and outcomes following posterior fossa decompression.

METHODS

Medical records of all patients <18 years who underwent surgery for Chiari I malformation between 1/1/09 and 1/31/21 at the Ann & Robert H. Lurie Children's Hospital of Chicago were included. Records were reviewed for patient characteristics, anesthesia-related intraoperative complications, postoperative complications, and surgical outcomes. The primary outcome was the incidence of unanticipated admission to the intensive care unit, and the primary variable of interest was an anesthesia-related intraoperative complication. Patient, surgical characteristics, and year of surgery were also compared between patients with and without an unanticipated admission to the intensive care unit, and a multi-variable adjusted estimate of odds of unanticipated admission to the intensive care unit admission following an anesthesia-related intraoperative complication was performed. Secondary outcomes included anesthesia factors associated with an anesthesia-related intraoperative event, and postoperative complications and surgical outcomes between patients admitted to the intensive care unit and those who were not.

RESULTS

Two hundred ninety-six patients with Chiari I Malformation were identified. Clinical characteristics associated with an unanticipated admission to the intensive care unit were younger age, American Society of Anesthesiologist (ASA) physical status >2 and an anesthesia-related intraoperative complication. 29 anesthesia-related intraoperative complications were observed in 25 patients (8.4%). Two of 25 patients (8%) with an anesthesia-related intraoperative complication compared with 3 of 271 (1%) patients without anesthesia-related intraoperative complication had an unanticipated admission to the intensive care unit, odds ratio 7.8 (95% CI 1.2-48.8, p = .010). When adjusted for age, sex, ASA physical status, presenting symptoms, concomitant syringomyelia, previous decompression surgery and year of surgery, the odds ratio for an unanticipated admission to the intensive care unit following an anesthesia-related intraoperative complication was 5.9 (95% CI 0.51-59.6, p = .149). There were no differences in surgical outcomes between patients with or without an unanticipated admission to the intensive care unit.

CONCLUSION

Our study demonstrates that although anesthesia-related intraoperative complications during posterior fossa decompression are infrequent, they are associated with an increased risk of an unanticipated admission to the intensive care unit.

Comparison of Dural Graft Types and Graft Fixation Methods in Chiari Malformation Type I Decompression Surgery

OBJECTIVE

Suboccipital decompression with duraplasty is being increasingly accepted for treating patients with Chiari malformation type I (CM-1). To date, the optimal duraplasty for CM-I has not been delineated. This study aims to compare the clinical and radiologic effects of duraplasty performed using 2 types of grafts and 2 graft fixation methods in 3 combinations.

METHODS

In this retrospective study, 84 consecutive decompressions with duraplasty were analyzed. Two types of grafts (nonautologous [Non-Auto G], 90.5% and autologous [Auto G], 9.5%) and 2 graft fixations (suturing [S], 31.0%; and suturing plus gluing [S + G], 69.0%) were used in 3 different combinations: Non-Auto G S: 31.0%; Non-Auto G S + G: 59.5%, and Auto G S + G: 9.5%. All patients were followed up for 3 months. Clinical results were evaluated using the Gestalt scale, and syringomyelia results were evaluated using magnetic resonance imaging.

RESULTS

According to the Gestalt scale, 82.1% of the patients showed improvement 3 months post operation, and the improvement was not related to the type of graft (P = 0.90), fixation (P = 0.90), or duraplasty (P = 0.81). Decreased syringomyelia was observed in 76.4% of the patients. It was not associated with the graft (P = 0.53), fixation (P = 0.72), or duraplasty (P = 0.80). Meningitis occurred in the Auto G S + G, Non-Auto G S + G and Non-Auto G S groups (25%, 48%, and 23.1%, respectively; P = 0.30), and their formations were not related to the k graft type (P = 0.57) or fixation (P = 0.19).

CONCLUSIONS

Autologous and nonautologous dural grafts can be performed using either sutures or sutures plus glue, as both result in similar outcomes.

Comparison of Pericranial Autograft and AlloDerm for Duraplasty in Patients With Type I Chiari Malformation: Retrospective Cohort Analysis

BACKGROUND

Pericranial autograft is a popular option for duraplasty during Chiari decompression with several theoretical advantages, but comparisons to other materials have yielded mixed results.

OBJECTIVE

To compare outcomes between pericranial autograft and AlloDerm (BioHorizons).

METHODS

Consecutive suboccipital craniectomies for patients with type I Chiari malformation (CM-I) over an 8-yr period at a single institution were identified. Exclusion criteria included revision surgeries and suboccipital decompressions without duraplasty. Outcomes included incisional cerebrospinal fluid (CSF) leakage, length of stay (LOS), wound complication, aseptic meningitis, syrinx improvement, and symptomatic improvement.

RESULTS

A total of 101 patients (70 females and 31 males) with a median (interquartile range) age of 17 yr (11-32) met the inclusion criteria. There were 51 (50%) patients who underwent duraplasty with pericranial autograft, and the remainder underwent duraplasty with AlloDerm. There were 9 (9%) patients who experienced a postoperative CSF leak. After adjusting for confounding factors, obesity (odds ratio [OR]: 4.69, 95% CI: 1.03-25.6) and use of AlloDerm (OR: 10.54, 95% CI: 1.7-206.12) were associated with CSF leak. Wound complication occurred in 8 (8%) patients but was not associated with graft type (P = .8). Graft type was not associated with LOS, syrinx improvement, or symptom improvement. Reoperations occurred in 10 patients with 4 in the autograft group and 6 in the AlloDerm group (P = .71).

CONCLUSION

In patients with CM-I, expansile duraplasty with AlloDerm was associated with greater odds of CSF leakage than pericranial autograft. Obesity was also associated with increased odds of CSF leakage.

Delayed chemical meningitis after Chiari decompression with duraplasty: illustrative cases

BACKGROUND

Dural reconstruction to achieve expansion duraplasty is important in suboccipital decompression for Chiari malformation type 1 (CM1). Although various dural substitutes are available, including synthetic collagen matrix grafts and dural xenografts, they have the potential to induce an inflammatory response. In this case series, the authors present their experience and discuss the incidence and possible mechanism of aseptic meningitis after the use of bovine collagen matrix graft as a dural substitute in patients with CM1 after suboccipital decompression.

OBSERVATIONS

Three consecutive adult female patients who underwent suboccipital decompression at a single institution by a single neurosurgeon were retrospectively reviewed. They all presented with signs of aseptic meningitis in a delayed fashion, responded well to steroid administration, but had recurrence of their symptoms. Bovine collagen dural substitutes are resorbed in a process that induces an inflammatory response manifesting with signs of aseptic meningitis and is only alleviated with removal of the dural substitute.

LESSONS

DuraMatrix Suturable, a dural xenograft derived from bovine dermis, though a viable choice for dural repair, is a potential cause of chemical meningitis after duraplasty in Chiari decompression surgery. In patients presenting with delayed and persistent aseptic meningitis after intervention, removal of this dural substitute led to improved symptomatology.

Differentiation of Chiari malformation type 1 and spontaneous intracranial hypotension using objective measurements of midbrain sagging

OBJECTIVE

Chiari malformation type 1 (CM-1) and spontaneous intracranial hypotension (SIH) are causes of headache in which cerebellar tonsillar ectopia (TE) may be present. An accurate method for differentiating these conditions on imaging is needed to avoid diagnostic confusion. Here, the authors sought to determine whether objective measurements of midbrain morphology could distinguish CM-1 from SIH on brain MRI.

METHODS

This is a retrospective case-control series comparing neuroimaging in consecutive adult subjects with CM-1 and SIH. Measurements obtained from brain MRI included previously reported measures of brain sagging: TE, slope of the third ventricular floor (3VF), pontomesencephalic angle (PMA), mamillopontine distance, lateral ventricular angle, internal cerebral vein-vein of Galen angle, and displacement of iter (DOI). Clivus length (CL), an indicator of posterior fossa size, was also measured. Measurements for the CM-1 group were compared to those for the entire SIH population (SIHall) as well as a subgroup of SIH patients with > 5 mm of TE (SIHTE subgroup).

RESULTS

Highly significant differences were observed between SIHall and CM-1 groups in the following measures: TE (mean ± standard deviation, 3.1 ± 5.7 vs 9.3 ± 3.5 mm), 3VF (-16.8° ± 11.2° vs -2.1° ± 4.6°), PMA (44.8° ± 13.1° vs 62.7° ± 9.8°), DOI (0.2 ± 4.1 vs 3.8 ± 1.6 mm), and CL (38.3 ± 4.5 vs 44.0 ± 3.3 mm; all p < 0.0001). Eight (16%) of 50 SIH subjects had TE > 5 mm; in this subgroup (SIHTE), a cutoff value of < -15° for 3VF and < 45° for PMA perfectly discriminated SIH from CM-1 (sensitivity and specificity = 1.0). DOI showed perfect specificity (1.0) in detecting SIH among both groups. No subjects with SIH had isolated TE without other concurrent findings of midbrain sagging.

CONCLUSIONS

Measures of midbrain sagging, including cutoff values for 3VF and PMA, discriminate CM-1 from SIH and may help to prevent misdiagnosis and unnecessary surgery.

Foramen magnum decompression in adults with Chiari type 1 malformation: use of intraoperative ultrasound to guide extent of surgery

BACKGROUND

Foramen magnum decompression (FMD) is an established technique for patients with Chiari-1 malformation. However, the extent of decompressive surgery is controversial, in particular whether dural opening is undertaken.

OBJECTIVE

In this study, we report outcomes with our technique utilising intraoperative ultrasound (iOU) findings. Decision to proceed for further decompression was based on CSF flow around foramen magnum and visualisation of tip of tonsils.

METHODS

Review of adults with CM-1 undergoing FMD 2013-2018. Patients underwent a suboccipital craniectomy ± partial C1 superior laminectomy ± duraplasty in a stepwise manner. Favourable iOU findings of CSF flow around the foramen magnum and pulsation of the tonsillar tips were sought at each step. Post-operative outcomes were assessed using the Chicago Chiari Outcome Score (CCOS).

RESULTS

Fifty-seven patients were included. The mean age was 47 years (range 18-77 years). There was a strong female preponderance (48 females to nine males). The mean follow-up was 3.2 years (range 1-5 years). Surgery included: suboccipital craniectomy (52/57, 91%), plus partial C1 superior laminectomy (2/57, 4%), and plus duraplasty (3/57, 6%). Redo surgery was undertaken in 7/57 patients (12%). At final follow-up, 56/57 (98%) patients achieved a good (CCOS 13-16) or satisfactory (CCOS 9-12) outcome based on COSS.

CONCLUSIONS

A patient centred approach to surgery utilising findings from iOU can achieve favourable outcomes. Dural opening is not routinely required.

Outcomes for various dural graft materials after posterior fossa decompression with duraplasty for Chiari malformation type I: a systematic review and meta-analysis

OBJECTIVE

Posterior fossa decompression with duraplasty (PFDD) is often used for Chiari malformation type I (CM-I), but outcomes associated with different dural graft materials are not well characterized. In this meta-analysis, the authors examined complication rates and outcomes after PFDD for CM-I for autografts and four types of nonautologous grafts.

METHODS

A literature search of numerous electronic databases (Ovid Medline, Embase, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects, Health Technology Assessment Database, NHS Economic Evaluation Database, and ClinicalTrials.gov) was performed to identify articles detailing complications for dural graft materials after PFDD. Whenever available, data were also extracted regarding the need for revision surgery, symptom changes after PFDD, and syrinx size changes after PFDD. All searches were compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), Institute of Medicine, Standards for Systematic Reviews, Cochrane Handbook for Systematic Reviews of Interventions, and Peer Review of Electronic Search Strategies guidelines. There were no exclusion criteria based on patient age or presence or absence of syringomyelia.

RESULTS

The current evidence surrounding outcomes for various dural graft materials was found to be of low or very low quality. Twenty-seven studies were included, encompassing 1461 patients. Five types of dural graft materials were included: autograft (n = 404, 27.6%), synthetic (n = 272, 18.6%), bovine pericardium (n = 181, 12.4%), collagen-based (n = 397, 27.2%), and allograft (n = 207, 14.2%). Autograft was associated with a significantly lower rate of pseudomeningocele compared to collagen-based grafts, allografts, and nonautologous grafts in aggregate. Autograft was also associated with the lowest rates of aseptic meningitis, infectious meningitis, and need for revision PFDD, though these associations did not reach statistical significance. No other graft comparisons yielded significant results. Autograft and nonautologous graft materials yielded similar rates of revision surgery and produced similar improvements in postoperative symptoms and syrinx size.

CONCLUSIONS

Autograft was the dural graft material that most frequently had the lowest rate of complications and was associated with significantly lower rates of pseudomeningocele compared to collagen-based graft, allograft, and nonautologous graft materials. Autografts and nonautologous grafts yielded similar outcomes for revision surgery, symptoms, and syrinx size. Large prospective studies comparing different graft materials are needed to accurately and precisely characterize outcomes for individual graft types.

Dural augmentation approaches and complication rates after posterior fossa decompression for Chiari I malformation and syringomyelia: a Park-Reeves Syringomyelia Research Consortium study

OBJECTIVE

Posterior fossa decompression with duraplasty (PFDD) is commonly performed for Chiari I malformation (CM-I) with syringomyelia (SM). However, complication rates associated with various dural graft types are not well established. The objective of this study was to elucidate complication rates within 6 months of surgery among autograft and commonly used nonautologous grafts for pediatric patients who underwent PFDD for CM-I/SM.

METHODS

The Park-Reeves Syringomyelia Research Consortium database was queried for pediatric patients who had undergone PFDD for CM-I with SM. All patients had tonsillar ectopia ≥ 5 mm, syrinx diameter ≥ 3 mm, and ≥ 6 months of postoperative follow-up after PFDD. Complications (e.g., pseudomeningocele, CSF leak, meningitis, and hydrocephalus) and postoperative changes in syrinx size, headaches, and neck pain were compared for autograft versus nonautologous graft.

RESULTS

A total of 781 PFDD cases were analyzed (359 autograft, 422 nonautologous graft). Nonautologous grafts included bovine pericardium (n = 63), bovine collagen (n = 225), synthetic (n = 99), and human cadaveric allograft (n = 35). Autograft (103/359, 28.7%) had a similar overall complication rate compared to nonautologous graft (143/422, 33.9%) (p = 0.12). However, nonautologous graft was associated with significantly higher rates of pseudomeningocele (p = 0.04) and meningitis (p < 0.001). The higher rate of meningitis was influenced particularly by the higher rate of chemical meningitis (p = 0.002) versus infectious meningitis (p = 0.132). Among 4 types of nonautologous grafts, there were differences in complication rates (p = 0.02), including chemical meningitis (p = 0.01) and postoperative nausea/vomiting (p = 0.03). Allograft demonstrated the lowest complication rates overall (14.3%) and yielded significantly fewer complications compared to bovine collagen (p = 0.02) and synthetic (p = 0.003) grafts. Synthetic graft yielded higher complication rates than autograft (p = 0.01). Autograft and nonautologous graft resulted in equal improvements in syrinx size (p < 0.0001). No differences were found for postoperative changes in headaches or neck pain.

CONCLUSIONS

In the largest multicenter cohort to date, complication rates for dural autograft and nonautologous graft are similar after PFDD for CM-I/SM, although nonautologous graft results in higher rates of pseudomeningocele and meningitis. Rates of meningitis differ among nonautologous graft types. Autograft and nonautologous graft are equivalent for reducing syrinx size, headaches, and neck pain.

Cerebrospinal fluid leakage after cranial surgery in the pediatric population-a systematic review and meta-analysis

BACKGROUND

Cerebrospinal fluid (CSF) leakage is a common complication after neurosurgical intervention. It is associated with substantial morbidity and increased healthcare costs. The current systematic review and meta-analysis aim to quantify the incidence of cerebrospinal fluid leakage in the pediatric population and identify its risk factors.

METHODS

The authors followed the PRISMA guidelines. The Embase, PubMed, and Cochrane database were searched for studies reporting CSF leakage after intradural cranial surgery in patients up to 18 years old. Meta-analysis of incidences was performed using a generalized linear mixed model.

RESULTS

Twenty-six articles were included in this systematic review. Data were retrieved of 2929 patients who underwent a total of 3034 intradural cranial surgeries. Surprisingly, only four of the included articles reported their definition of CSF leakage. The overall CSF leakage rate was 4.4% (95% CI 2.6 to 7.3%). The odds of CSF leakage were significantly greater for craniectomy as opposed to craniotomy (OR 4.7, 95% CI 1.7 to 13.4) and infratentorial as opposed to supratentorial surgery (OR 5.9, 95% CI 1.7 to 20.6). The odds of CSF leakage were significantly lower for duraplasty use versus no duraplasty (OR 0.41 95% CI 0.2 to 0.9).

CONCLUSION

The overall CSF leakage rate after intradural cranial surgery in the pediatric population is 4.4%. Risk factors are craniectomy and infratentorial surgery. Duraplasty use is negatively associated with CSF leak. We suggest defining a CSF leak as "leakage of CSF through the skin," as an unambiguous definition is fundamental for future research.

Persistent aseptic meningitis in a child-think patch

BACKGROUND

In patients with neurosurgical interventions requiring dura reconstruction, the use of bovine graft material may be required.

PATIENTS AND METHODS

Case report.

RESULTS

We present a 12-year-old girl with a profound graft reaction with severe neurologic symptoms mimicking post-neurosurgical bacterial meningitis after resection of an infra-tentorial brain tumour.

CONCLUSION

It is important to take into consideration this rare clinical entity in children and adults after dura reconstruction using allogenic graft (bovine) material in order to avoid the unnecessary use of antibiotics and antiviral drugs.

Chiari type I malformation: role of the Chiari Severity Index and Chicago Chiari Outcome Scale

OBJECTIVE

The authors aimed to determine whether the Chiari Severity Index (CSI), and other clinical variables, can be used as a predictor of postoperative outcomes for Chiari type I malformation (CM-I) using the modified Chicago Chiari Outcome Scale (mCCOS) as the postoperative measure.

METHODS

The cohort included patients 18 years of age and younger who were treated for CM-I between 2010 and 2015 who had at least 12 months of clinical and radiographic follow-up. CSI grades were assigned using preoperative clinical and neuroimaging data. Clinical, radiographic, and operative data were obtained from medical records. Kruskal-Wallis tests and Spearman correlations were conducted to assess for differences among CSI grades. Linear and ordinal regressions were conducted to evaluate predictors of the mCCOS and its components. Statistical significance was set a priori at p < 0.05.

RESULTS

A total of 65 patients were included in the final cohort. The average age at the time of surgery and the mean mCCOS score were 9.8 ± 4.9 years and 10.4 ± 1.4, respectively. There were no significant differences in the mean mCCOS scores or CSI grades. Pre- and postoperative syrinx sizes were similar across the total patient cohort with median sizes of 7.4 and 3.7 mm, respectively. After controlling for age at the time of surgery, whether duraplasty and/or arachnoid dissection was performed, CSI preoperative score did not predict postoperative mCCOS score. No clinical variable could predict total mCCOS score. When the mCCOS was broken down into 3 subcomponents (pain, non-pain, and complications), only one relationship was identified. Those patients who presented with no headache had a statistically significant decrease in their pain (neck pain, shoulder pain, or dysesthesia in the upper extremities) as measured by the pain component of the mCCOS (χ2 [2, n = 20] = 6.43, p = 0.04). All other preclinical predictors, including CSI grades, were nonsignificant in demonstrating correlations to the mCCOS subcomponents.

CONCLUSIONS

CSI grade was not found to be a marker of surgical outcome as measured by the mCCOS in this study. There were no correlations between the clinical variables and covariates investigated with the mCCOS. The lack of variation in mCCOS scores across this cohort may suggest that the mCCOS is not adequate for detecting differences in postsurgical outcomes. Further investigation is warranted to make this determination.

Spinal cord infarction with resultant paraplegia after Chiari I decompression: case report

Paraplegia after posterior fossa surgery is a rare and devastating complication. The authors reviewed a case of paraplegia following Chiari decompression and surveyed the literature to identify strategies to reduce the occurrence of such events.An obese 44-year-old woman had progressive left arm pain, weakness, and numbness and tussive headaches. MRI studies revealed a Chiari I malformation and a cervicothoracic syrinx. Immediately postoperatively after Chiari decompression the patient was paraplegic, with a T6 sensory level bilaterally. MRI studies revealed equivocal findings of epidural hematoma at the site of the Chiari decompression and in the upper thoracic region. Surgical exploration of the Chiari decompression site and upper thoracic laminectomies identified possible venous engorgement, but no hematoma. Subsequent imaging suggested a thoracic spinal cord infarction. Possible explanations for the spinal cord deficit included spinal cord ischemia related to venous engorgement from prolonged prone positioning in an obese patient in the chin-tucked position. At 6.5 years after surgery the patient had unchanged fixed motor and sensory deficits.Spinal cord infarction is rare after Chiari decompression, but the risk for this complication may be increased for obese patients positioned prone for extended periods of time. Standard precautions may be insufficient and intraoperative electrophysiological monitoring may need to be considered in these patients.

Conservative management for pediatric patients with chiari 1 anomaly: A retrospective study

OBJECTIVE

To better understand the natural history of non-surgical management of chiari 1 anomaly.

PATIENTS AND METHODS

After obtaining approval of the institutional review board, medical records and radiological exams of patients treated for CM1 at our institution between the years 2010 and 2016 were reviewed. Twenty-nine patients total were included in our study.

RESULTS

The average age of our patient population was 8.5 years old at the time of diagnosis. The average tonsillar herniation on first MRI was 9.4 mm (+/- 4.6) and the average tonsillar herniation on second MRI was 10.4 mm (+/- 4.8). The average follow up time of our sample of patients was 26 months. Of the 29 patients in our study 9 (31 %) had symptomatic presentation. Interestingly, four of our patients (13.8 %) presented with epilepsy.

CONCLUSIONS

Our findings support the previous work that nonoperative management is best in asymptomatic or mildly symptomatic chiari patients.

Outcomes and complications for individual neurosurgeons for the treatment of Chiari I malformation at a children's hospital

PURPOSE

The aim of this study was to evaluate the outcomes and complications for individual surgeons at British Columbia Children's Hospital for the treatment of Chiari I Malformation (CMI) in children.

METHODS

This was a retrospective review of patients with CMI who had surgery from 1986 to 2015. We assessed the Chicago Chiari Outcome Scores (CCOS) and complication rates by surgeon.

RESULTS

Seventy patients, 38 males and 32 females, underwent posterior fossa decompression including 14 extradural and 56 intradural approaches. Syringomyelia was present in 74.3%. Most syringomyelia improved with no difference between intradural and extradural surgeries. After initial surgery, 13 patients (18.6%) had complications including 2/14 (14.3%) of extradural and 11/56 (19.6%) of intradural surgeries. Two patients required surgical intervention for complications whereas 11 had transient complications. The complication rate by surgeon ranged from 11 to 20% for extradural (2 surgeons only) and 10.5 to 40% for intradural surgeries (4 surgeons). The CCOS ranged from 12 to 15 for extradural and 6 to 16 for intradural. The CCOS ranges for surgeons 1 and 2 were 12-15 and 13-15 respectively for extradural. The CCOS ranges for surgeons 1, 2, 3, and 4 were 12-16, 6-15, 12-16, and 12-16 respectively for intradural. Thirteen patients had a second surgery for CMI. The final CCOS was good in 86% and moderate in 14%.

CONCLUSION

There was variability in surgeries performed at BCCH by different surgeons, with variations in CCOS and complication rates. This information is important during decision making, consent process, and for quality improvement.

Posterior fossa decompression for Chiari malformation type I: clinical and radiological presentation, outcome and complications in a retrospective series of 105 procedures

OBJECTIVE

Determining clinical and radiological characteristics, complication rates and outcome for patients undergoing posterior fossa decompression (PFD) and duraplasty for Chiari malformation type I (CM-I).

METHODS AND MATERIALS

Retrospective, single-university hospital study of all PFDs for CM-I between January 1995 and December 2016.

RESULTS

PFD was performed in 105 patients with CM-I (n = 105), of whom 62 suffered from associated syringomyelia and 37 were pediatric cases. There was a female preponderance in the syringomyelia, non-syringomyelia, pediatric and adult groups (62.9%, 65.1%, 54.1% and 69.1%, respectively). Mean age at diagnosis was higher in the syringomyelia group (32.3 versus 26.9 years, p = 0.06) and in both groups delay for diagnosis was long (33.4 and 47.1 months, p = 0.50). Headache during Valsalva maneuver and on exertion was significantly more present in the non-syringomyelia group (27.9% versus 16.1%, p < 0.0001 and 39.5% versus 11.3%, p = 0.0009); cranial nerve dysfunction and cerebellar signs did not differ significantly (p = 0.07 and p = 0.53). Spinal cord syndrome was significantly more present in the syringomyelia group (72.6% versus 25.6%, p < 0.0001). Scoliosis was present in five patients, of whom four had syringomyelia. Duraplasty was performed in 101 surgeries. For 100 patients, PFD was the primary treatment of CM-I; 2 patients had previously undergone syrinx drainage and 3 ventriculoperitoneal shunting for hydrocephalus. Only one patient presented with hydrocephalus. Duraplasty (n = 101) was complicated by CSF leak in 4.0% (n = 4), symptomatic pseudomeningocele in 4.0% (n = 4), aseptic meningitis in 2.0% (n = 2) and hydrocephalus in 1.0% (n = 1). Osseous decompression without duraplasty was performed in only four highly selected patients, not allowing a comparative analysis with duraplasty. Post-operative symptom improvement is reported for 67.3% of all patients and stabilization of symptoms in 23.9%. Symptom improvement was significantly more frequent in the non-syringomyelia group (p = 0.03). Outcome seemed similarly good in the pediatric and the adult groups.

CONCLUSION

PFD performed with duraplasty is a safe procedure. The majority of patients do report symptom stabilization or improvement. Non-syringomyelia patients reported significantly more frequent improvement of clinical symptoms.

Bony Decompression for Chiari Malformation Type I: Long-Term Follow-Up

BACKGROUND

Several surgical techniques are used for the management of Chiari malformation type I (CM-I). Bony posterior fossa decompression is considered a good option in children, though with a higher risk of requiring reoperation. However, there is not enough evidence from the series in the literature, which are often limited by inadequate follow-up. The goal of this study was to assess the effectiveness of suboccipital craniectomy alone in children after long-term follow-up.

METHODS

Forty-two children (25 female and 17 male; mean age 6.7 years), operated on with bony decompression alone, were retrospectively reviewed. All patients underwent suboccipital craniectomy. Thirty-eight children required C1 laminectomy, and 21 also underwent dural delamination on the basis of intraoperative ultrasound investigations. The outcome was assessed using the traditional measurement and the Chicago Chiari Outcome Scale (CCOS). The mean follow-up period was 11.3 years (range 5-15 years).

RESULTS

Headache was the most frequent preoperative symptom (81%), followed by neck pain (40%), vertigo (40%), ataxia (26%), and upper and lower extremity paraesthesia (26%). Syringomyelia was present in 19 patients (45%). Resolution and significant improvement of preoperative clinical symptoms were observed in 36.5% and 21.5% of cases, respectively. Three children required adjunctive surgery for symptom recurrence (7%). The tonsil position and syringomyelia were normalized or improved in 50% and 79% of cases, respectively. No complications occurred. According to the CCOS scores, 69.5% of children had an excellent outcome, 28.5% had a functional outcome and 2% had an impaired outcome.

CONCLUSION

Bony decompression alone is an effective, safe and long-lasting treatment for children with CM-I. A certain risk of symptom recurrence requiring new surgery exists, but it is widely counterbalanced by the low risk of complications. Careful patient selection is crucial for a good outcome. Prospective and randomized studies are needed for further validation.

Chiari 1 Malformation Surgery: Comparing Non-violation of the Arachnoid versus Arachnoid Opening and Thermocoagulation of the Tonsils

OBJECTIVE

Evidence is lacking concerning the myriad surgical techniques for type 1 Chiari malformation. This study evaluated the impact of arachnoid violation with tonsil thermocoagulation during surgical craniovertebral junction decompression.

METHODS

The evaluation included aspects of the neurologic examination and parameters of cerebrospinal fluid flow on magnetic resonance imaging during preoperative and postoperative periods. All patients underwent craniovertebral junction decompression and opening of the dura mater. Patients were divided into 2 study groups. Patients in group 1 did not undergo arachnoid violation. Patients in group 2 underwent tonsil manipulation and systematic opening of the fourth ventricle outlet.

RESULTS

There were 16 patients enrolled in each group (total of 32 patients). Regarding clinical improvement, there were no significant differences between groups in the postoperative period. Group 2 had more adverse events (relative risk 2.45, 95% confidence interval 1.55-3.86). In terms of cerebrospinal fluid flow parameter analyses, patients in group 1 achieved better results (P < 0.05).

CONCLUSIONS

For treatment of symptomatic type 1 Chiari malformation, craniovertebral junction decompression with arachnoid preservation (i.e., without tonsillar manipulation) seems more suitable than the addition of arachnoid opening and thermocoagulation of the tonsils.

Autologous cervical fascia duraplasty in 123 children and adults with Chiari malformation type I: surgical technique and complications

OBJECT Techniques for combined extradural and intradural decompression with expansile duraplasty for Chiari malformation type I (CM-I) have been well described, with various allogenic and autologous materials used for duraplasty. However, the approach and surgical technique used for duraplasty in our treatment of CM-I and developed by the senior author in the 1990s has not been described. METHODS A prospective database was initiated in March 2003 to denote the use of cervical fascia for duraplasty and incorporate an ongoing detailed record of complications during the surgical treatment of children and adults with CM-I with and without syringomyelia. A total of 389 surgeries for CM-I were performed on 379 patients from March 2003 to June 2016. A total of 123 posterior procedures were performed on 123 patients in which both a posterior fossa extradural and intradural decompression with duraplasty (extra-intradural) was performed. In this paper the authors describe the surgical technique for harvesting and using cervical fascia for duraplasty in the surgical treatment of CM-I and analyze and discuss complications from a prospective database spanning 2003-2016. RESULTS The authors found that cervical fascia can be harvested in patients of all ages (2-61 years old) without difficulty, and it provides a good substitute for dura in creating an expansile duraplasty in patients with CM-I. Cervical fascia is an elastic-like material with a consistency that allows for a strong watertight closure. Harvesting the cervical fascia graft does not require any further extension of the incision superiorly or inferiorly to obtain the graft. Complications were uncommon in this study of 123 children and adults. The risk of any type of complication (aseptic meningitis, CSF leak, pseudomeningocele, infection, development of hydrocephalus, and need for ventriculoperitoneal shunt) for the 78 patients in the pediatric age group was 0%. The risk of complication in the adult group was 6.7% (1 patient with aseptic meningitis and 2 patients with CSF leak). CONCLUSIONS Autologous cervical fascia is easy to obtain in patients of all ages and provides an effective material for duraplasty in the treatment of CM-I. Complications from the combination of both an extradural and intradural decompression with autologous cervical fascia duraplasty are uncommon.

Duraplasty Type as a Predictor of Meningitis and Shunting After Chiari I Decompression

BACKGROUND

Expansile duraplasty is frequently performed during Chiari I decompression. Aseptic and bacterial meningitis are possible complications of this procedure. We sought to compare the rates of meningitis and subsequent need for cerebrospinal fluid (CSF) diversion with duraplasty using bovine pericardial (BPC) xenograft and allograft.

METHODS

We conducted a retrospective review of 112 patients who underwent Chiari I decompression. All patients underwent duraplasty with either allograft or BPC. Occurrence of postoperative lumbar punctures and associated data were recorded to determine rates of meningitis. Rates of subsequent shunting were also recorded.

RESULTS

Overall, 112 patients were included in the study: 30 underwent duraplasty with allograft (27%) and 82 received BPC (73%). A total of 26 patients developed postoperative meningitis (23 cases of chemical meningitis and 3 of bacterial meningitis). Rates of meningitis were higher in patients who received BPC than patients who received allograft (28% vs. 10%, respectively; P = 0.047). The rate of shunting was greater in patients with meningitis compared with patients without meningitis (56.5% vs. 5.75%, respectively; P < 0.0001). Moreover, 13 of the 15 patients (87%) in the BPC cohort who were shunted were found to have meningitis compared with 0 of the 3 shunted patients (0%) in the allograft cohort (P = 0.044).

CONCLUSIONS

We found that rates of total meningitis were greater in patients who underwent Chiari I decompression and duraplasty with BPC compared with an allograft. The rate of shunting was significantly higher for patients who developed meningitis after decompression compared with patients without meningitis.

Time to Resolution of Symptoms After Suboccipital Decompression with Duraplasty in Children with Chiari Malformation Type I

BACKGROUND

Duraplasty is a technique successfully used to treat Chiari malformation type I (CM-I). This study describes the timely manner of clinical outcomes and the postoperative course after craniectomy and duraplasty for the treatment of symptomatic CM-I in children.

METHODS

A retrospective chart review was performed in 105 consecutive children who underwent surgical decompression of symptomatic CM-I with dural opening by a single surgeon between 1999 and 2015.

RESULTS

In 16 of 28 children (57%) with typical Valsalva-related/tussive and mixed headaches, the symptoms resolved before discharge; by 6 months, all children were headache-free. Two of 28 children (7%) had recurrent headaches 9 months after surgery. Among the 78 children with syrinx, syrinx resolved or decreased in 68 (87%), recurred in 8 (10%), and was stable in 2 children (3%). Syrinx was resolved or decreased by 3 months in 51 children (65%) and by 6 months in 62 children (79%). Complications included aseptic meningitis requiring reoperation in 3 children (3%) and infection in one child (1%). Twelve children underwent reoperation, none within the first 30 days. No child had a major morbidity or mortality.

CONCLUSIONS

In carefully selected children with CM-I, a high success rate can be achieved with suboccipital decompression and duraplasty. Valsalva-related/tussive headaches resolved by the time of discharge from the hospital in the majority of children, and syrinx resolved or decreased in two-thirds of the children by 3 months. By 6 months, headaches were resolved in all cases, and syrinx was resolved or decreased in 79% of cases.

International survey on the management of Chiari 1 malformation and syringomyelia: evolving worldwide opinions

INTRODUCTION

In 2003, pediatric neurosurgeons were surveyed under the auspices of the education committee of the International Society for Pediatric Neurosurgery (ISPN) to determine prevailing opinions regarding the management of Chiari I malformation (C1M) with and without associated syringomyelia. In the ensuing years, there has been further information from multiple C1M studies, with regards to indications, success rates of different surgical interventions, and complications. The purpose of this study was to re-evaluate current opinions and practices in pediatric C1M.

MATERIALS AND METHODS

Pediatric neurosurgeons worldwide were surveyed, using an e-mail list provided by the ISPN communication committee chairperson. Respondents were given scenarios similar to the 2003 C1M survey in order to determine opinions regarding whether to surgically intervene, and if so, with which operations.

RESULTS

Of 300 surveys electronically distributed, 122 responses were received (40.6% response rate)-an improvement over the 30.8% response rate in 2003. Pediatric neurosurgeons from 34 different countries responded. There was broad consensus that non-operative management is appropriate in asymptomatic C1M (> 90%) as well as asymptomatic C1M with a small syrinx (> 65%). With a large syrinx, a majority (almost 80%) recommended surgical intervention. Scoliotic patients with CIM were generally offered surgery only when there was a large syrinx. There has been a shift in the surgical management over the past decade, with a bone-only decompression now being offered more commonly. There remains, however, great variability in the operation offered.

CONCLUSION

This survey, with a relatively strong response rate, and with broad geographic representation, summarizes current worldwide expert opinion regarding management of pediatric C1M. Asymptomatic C1M and C1M with a small syrinx are generally managed non-operatively. When an operation is indicated, there has been a shift towards less invasive surgical approaches.

[Posterior decompression of the craniovertebral junction in syringomyelia combined with Chiari-1 malformation in children]

OBJECTIVE

to develop the algorithm for defining the amount of posterior decompression of the craniovertebral junction in children with syringomyelia combined with Chiari-1 malformation.

MATERIAL AND METHODS

Sixty eight children with syringomyelia and Chiari-1 malformation, under age of 18 years, underwent posterior decompression of the craniovertebral junction (PDCVJ) in the period from January 2001 to June 2016. Seven (10%) patients underwent extradural decompression (EDD), 16 (24%) patients underwent extra-arachnoid duraplasty (EAD), 25 (37%) patients underwent intra-arachnoid dissection (IAD) and duraplasty, and 20 (29%) patients underwent PDCVJ and placement of a fourth ventricle-subarachnoid shunt.

RESULTS

Clinical improvement occurred in 85% of patients, and stabilization was observed in 11% of patients. Syringomyelia regressed in 78% of cases. There were no complications associated with EDD; however, re-operation was required in 3 (43%) cases. In the case of EAD, treatment results were satisfactory in 11 (79%) patients; re-operation was required in 2 (12.5%) cases; there were no complications in the early postoperative period. The highest complication rate of 6 (30%) cases was associated with shunt placement and duraplasty. However, long-term results in this group of patients were satisfactory in 16 (94%) cases, and MRI-based positive changes were observed in 100% of cases.

CONCLUSION

According to our analysis, EAD is the method of choice for PDCVJ in children with syringomyelia and Chiari-1 malformation without myelopathy symptoms. In the presence of myelopathy symptoms, intra-arachnoid dissection (with or without shunting) is an acceptable alternative. To our opinion, the use of EDD in syringomyelia is unadvisable.

Use of an Absorbable Synthetic Polymer Dural Substitute for Repair of Dural Defects: A Technical Note

Repair of the dura after cranial neurosurgery can present a technical challenge and, for certain neurosurgical procedures, is critical to prevent cerebrospinal fluid leak and associated wound complications. Multiple options exist for dural repair, including the patient's own tissues, bovine collagen-derived commercially available grafts, as well as newer, entirely synthetic graft materials. This is the first report of surgical experience with a new synthetic and absorbable dura substitute which has recently gained Food and Drug Administration (FDA) approval. Four patients underwent dural reconstruction with a new graft material after cranial neurosurgery when the dura was unrepairable directly. The synthetic graft material demonstrated satisfactory surgical qualities, was effective in dural repair, and no complications were attributable to the graft. Dural repair after craniotomy is an often desirable surgical outcome in neurosurgery. Surgeons seeking new graft materials may find this new absorbable, entirely synthetic material favorable for dural repair.

The addition of duraplasty to posterior fossa decompression in the surgical treatment of pediatric Chiari malformation Type I: a systematic review and meta-analysis of surgical and performance outcomes

OBJECTIVE Surgery is the definitive treatment of Chiari malformation Type I (CM-I). It involves posterior fossa decompression, which can be performed along with C-1 laminectomy, reconstructive duraplasty, or tonsil shrinkage. The aim of this study was to provide an updated systematic review and meta-analysis of the latest available evidence regarding posterior fossa decompression only (PFDO) versus posterior fossa decompression with duraplasty (PFDD) in the treatment of CM-I in children. METHODS A literature search was performed in compliance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for article identification, screening, eligibility, and inclusion. Relevant articles were identified from 6 electronic databases from their inception to April 2016. These articles were screened against established criteria for inclusion into this study. RESULTS From 12 relevant studies identified, 1492 pediatric patients treated via PFDD were compared with 1963 pediatric patients treated by PFDO for CM-I. PFDD was associated with greater overall clinical improvement (p = 0.009), along with longer length of stay (p < 0.0001) and more postoperative complications (p = 0.0001) compared with PFDO. No difference was observed between PFDD and PFDO in terms of revision surgery incidence (p = 0.13), estimated blood loss (p = 0.14), syrinx improvement (p = 0.09), or scoliosis improvement (p = 0.95). CONCLUSIONS It appears that the addition of duraplasty to posterior decompression in the definitive treatment of CM-I in children may alter surgical and performance outcomes. In particular, parameters of overall clinical improvement, length of stay, and postoperative complication may differ between children undergoing PFDD and those undergoing PFDO. Current evidence in the literature is of low to very low quality that, as of yet, has not been able to completely control for inherent selection bias both in study design and surgeon preference. Future, large prospective registries and randomized controlled trials are warranted to validate the findings of this study.

Fibrin Sealants in Dura Sealing: A Systematic Literature Review

Background

Fibrin sealants are widely used in neurosurgery to seal the suture line, provide watertight closure, and prevent cerebrospinal fluid leaks. The aim of this systematic review is to summarize the current efficacy and safety literature of fibrin sealants in dura sealing and the prevention/treatment of cerebrospinal fluid leaks.

Methods

A comprehensive electronic literature search was run in the following databases: Cochrane Database of Systematic Reviews, Cochrane Central Resister of Controlled Trials, clinicaltrials.gov, MEDLINE/PubMed, and EMBASE. Titles and abstracts of potential articles of interest were reviewed independently by 3 of the authors.

Results

A total of 1006 database records and additional records were identified. After screening for duplicates and relevance, a total of 78 articles were assessed by the investigators for eligibility. Thirty-eight were excluded and the full-text of 40 articles were included in the qualitative synthesis. Seven of these included only safety data and were included in the safety assessment. The remaining 33 articles included findings from 32 studies that enrolled a total of 2935 patients who were exposed to fibrin sealant. Among these 33 studies there were only 3 randomized controlled trials, with the remaining being prospective cohort analysis, case controlled studies, prospective or retrospective case series. One randomized controlled trial, with 89 patients exposed to fibrin sealant, found a greater rate of intraoperative watertight dura closure in the fibrin sealant group than the control group (92.1% versus 38.0%, p<0.001); however, post-operative cerebrospinal fluid leakage occurred in more fibrin sealant than control patients (6.7% versus 2.0%, p>0.05). Other clinical trials evaluated the effect of fibrin sealant in the postoperative prevention of cerebrospinal fluid leaks. These were generally lower level evidence studies (ie, not prospective, randomized, controlled trials) that were not designed or powered to demonstrate a significant advantage to fibrin sealant use. Two small case series studies evaluated the effect of fibrin sealants in persistent cerebrospinal fluid leak treatment, but did not establish firm efficacy conclusions. Specific adverse reports where fibrin sealants were used for dura sealing were limited, with only 8 cases reported in neurosurgical procedures since 1987 and most reporting only a speculative relationship/association with fibrin sealant exposure.

Conclusions

A major finding of this systematic literature review is that there is a paucity of randomized studies that have evaluated the effectiveness and safety of fibrin sealants in providing intraoperative watertight dura closure and post-operative cerebrospinal fluid leakage. Among the limited studies available, evidence from a single randomized, controlled trial indicates that fibrin sealants provide a higher rate of intraoperative watertight closure of the dura suture line than control, albeit with a higher rate of postoperative cerebrospinal fluid leakage. Evidence from non-randomized, controlled trials suggests that fibrin sealants may be effective in preventing cerebrospinal fluid leaks with an acceptable safety profile. There is a substantial need for randomized, controlled clinical trials or well-designed prospective observational trials where the conduct of a randomized trial is not feasible to fully assess the impact of fibrin sealant utilization on the rates of intraoperative dura closure, postoperative cerebrospinal leakage, and safety.

Results of surgical treatment of syringomyelia associated with Chiari 1 malformation. An analysis of 125 cases

The rate of Chiari malformation (CM) in a population ranges from 3 to 8 per 100,000 population. In 62-80% of cases, CM is accompanied by the development of syringomyelia (SM) at various levels. The clinical picture in these patients is a combination of CM and SM manifestations; however, SM symptoms often prevail, which creates some problems in the diagnosis of the disease and in the choice of optimal treatment.

OBJECTIVE

On the basis of our own experience of surgical interventions, we aimed to clarify the indications for surgical treatment of SM associated with CM and to determine the optimal amount of surgery and the criteria for evaluation of treatment outcomes.

MATERIAL AND METHODS

Two hundred twenty five patients with a combination of syringomyelia and Chiari 1 malformation were examined in the period from 2011 to February 2015. Of them, 125 patients were operated on. The mean age of the operated patients was 56±8 years. The mean time from the appearance of the first signs of the disease to surgery was 75±82 months. All operations were performed by a single surgeon. The operations were carried out in the half-sitting (89.6%) or prone (10.4%) position. The operation included sparing suboccipital craniectomy, C1 arch resection, recovery of the cerebrospinal fluid (CSF) circulation along the posterior surface of the cerebellum, and reconstruction of the dura mater in the craniovertebral junction region.

RESULTS

Exploration of the arachnoid mater of the cisterna magna after dura opening revealed no arachnopathy in 78 (62.4%) patients (Chiari 0 malformation according to Klekamp). The type 1 arachnopathy (by Klekamp) was detected in 31 patients (24.8%), and the type 2 arachnopathy was observed in 16 (12.8%). The condition of 109 (88%) patients was evaluated one year after the surgery. Sixty one (56%) patients had partial or complete regression of preoperative neurological symptoms. The disease stopped progressing in 44 patients (40%). The disease was progressing in 4 (3.7%) patients. No recurrence of a CSF circulation disturbance at the craniovertebral level was observed during follow-up. Early postoperative complications occurred in 4 (3.2%) patients: wound CSF leakage in 1 (0.8%) patient, acute epidural hematoma in 1 (0.8%) patient, and aseptic meningitis in 2 (1.6%) patients. Temporary deteriorations in the condition (headache worsening, meteosensitivity) were detected in 11 (8.9%) patients. These symptoms regressed by the end of the 1st postoperative month. There were no deaths.

CONCLUSIONS

The indication for surgery in patients with a combination of CM and SM is the presence of neurological symptoms associated with syringomyelia and their progression as well as headache caused by herniation of the cerebellar tonsils, which significantly deteriorates the patient's quality of life. The main criteria for evaluating the efficacy of treatment include stabilization of the clinical symptoms and/or improvement in the patient condition. Suboccipital craniectomy followed by reconstruction of the dura mater and recovery of the CSF circulation in the craniovertebral region is an effective treatment of syringomyelia associated with Chiari 1 malformation.

Clinical Outcome Measures in Chiari I Malformation

Chiari malformation type 1 (CM-I) is a common and often debilitating neurologic disease. Reliable evaluation of treatments has been hampered by inconsistent use of clinical outcome measures. A variety of outcome measurement tools are available, although few have been validated in CM-I. The recent development of the Chicago Chiari Outcome Scale and the Chiari Symptom Profile provides CM-I-specific instruments to measure outcomes in adults and children, although validation and refinement may be necessary.

Foramen Magnum Decompression and Duraplasty is Superior to Only Foramen Magnum Decompression in Chiari Malformation Type 1 Associated with Syringomyelia in Adults

STUDY DESIGN

Retrospective cohort study.

PURPOSE

To compare surgical results of foramen magnum decompression with and without duraplasty in Chiari malformation type 1 (CM-1) associated syringomyelia (SM).

OVERVIEW OF LITERATURE

The optimal surgical treatment of CM-1 associated with SM is unclear.

METHODS

Twenty-five cases of CM-1 with SM were included. There were 12 patients (48%) in the non-duraplasty group and 13 patients (52%) in the duraplasty group. The rate of improvement, state of postoperative SM size, amount of tonsillar herniation, preoperative symptom duration, complications and reoperation rates were analysed.

RESULTS

The rate of clinical improvement was significantly higher with duraplasty (84.6%) than without (33.3%, p <0.05). The rate of postoperative syrinx regression was significantly higher in the duraplasty group (84.6%) than in the non-duraplasty group (33.3%, p <0.05). One case in the duraplasty group needed a reoperation compared with five cases in the non-duraplasty group (p =0.059).

CONCLUSIONS

Duraplasty is superior to non-duraplasty in CM-1 associated with SM despite a slightly higher complication rate.

Outcomes after suboccipital decompression without dural opening in children with Chiari malformation Type I

OBJECT Symptomatic pediatric Chiari malformation Type I (CM-I) is most often treated with posterior fossa decompression (PFD), but controversy exists over whether the dura needs to be opened during PFD. While dural opening as a part of PFD has been suggested to result in a higher rate of resolution of CM symptoms, it has also been shown to lead to more frequent complications. In this paper, the authors present the largest reported series of outcomes after PFD without dural opening surgery, as well as identify risk factors for recurrence. METHODS The authors performed a retrospective review of 156 consecutive pediatric patients in whom the senior authors performed PFD without dural opening from 2003 to 2013. Patient demographics, clinical symptoms and signs, radiographic findings, intraoperative ultrasound results, and neuromonitoring findings were reviewed. Univariate and multivariate regression analyses were performed to determine risk factors for recurrence of symptoms and the need for reoperation. RESULTS Over 90% of patients had a good clinical outcome, with improvement or resolution of their symptoms at last follow-up (mean 32 months). There were no major complications. The mean length of hospital stay was 2.0 days. In a multivariate regression model, partial C-2 laminectomy was an independent risk factor associated with reoperation (p = 0.037). Motor weakness on presentation was also associated with reoperation but only with trend-level significance (p = 0.075). No patient with < 8 mm of tonsillar herniation required reoperation. CONCLUSIONS The vast majority (> 90%) of children with symptomatic CM-I will have improvement or resolution of symptoms after a PFD without dural opening. A non-dural opening approach avoids major complications. While no patient with tonsillar herniation < 8 mm required reoperation, children with tonsillar herniation at or below C-2 have a higher risk for failure when this approach is used.

Management of Chiari I malformation in children: effectiveness of intra-operative ultrasound for tailoring foramen magnum decompression

PURPOSE

Patients with Chiari I malformation (CM-1) commonly undergo foramen magnum decompression (FMD). However, there is no consensus on how this should be achieved. An approach would be to rationalize surgical steps based on pre-operative imaging and intra-operative findings. The aim of this study is to assess the usefulness of intra-operative ultrasound scanning (IOUS) in tailoring foramen magnum decompression in children with CM-1 and whether the use of IOUS is effective in reducing the risk of complications without increasing the need for re-operation.

METHOD

We performed a retrospective study. IOUS was utilized during FMD: a subjective assessment was made on whether there was adequate cerebellar tonsillar and/or CSF pulsation following suboccipital craniectomy. If there was adequate pulsation, the dura was not opened. Additional data were collected including age and gender of patients, presence of pre-operative syringomyelia, intra-operative ultrasound findings, length of follow-up, complications and radiological and clinical outcome. The statistical analysis was performed with XLStat®(Addinsoft SARL™, France).

RESULTS

Nineteen patients underwent FMD from June 2011 to December 2012. The mean age was 10.5 years; there were nine females and ten males. Eleven patients had syringomyelia at diagnosis. Based on IOUS, eight patients underwent dural decompression and 11 patients bony decompression only. One patient had a post-operative pseudomeningocoele and two patients required re-operation. There was no significant statistical difference between the two groups regarding post-operative improvement in the syrinx.

CONCLUSION

We found that tailoring FMD for patients with CM-1 using intra-operative findings using ultrasound scan was useful in avoiding unnecessary manoeuvres, while not compromising on the outcome.

Pseudomeningocele formation following chiari decompression: 19-year retrospective review of predisposing and prognostic factors

BACKGROUND

Pseudomeningocele is a known operative complication of Chiari decompression with significant morbidity.

METHODS

A retrospective analysis of 150 consecutive patients from November 1991 to June 2011 was conducted. Symptomatic pseudomeningocele was defined clinically; to meet definition it must have required operative intervention. Variables evaluated included sex, age, use of graft, and use of operative sealant. The Chi-square, Fisher test, and the two-sample t-test were used as appropriate to determine significance. Multiple logistic regression was used to determine independent risk factors for complication.

RESULTS

A total of 67.3% of patients were female, with average age being 39.7 years. A total of 67.3% of patients had a graft placed with the most common being fascia lata. Only nine patients (6%) presented with pseudomeningocele. Factors observed to be significantly associated with pseudomeningocele development were age and use of sealant. Age and sealant use were also independent risk factors for complication. Adjusted for the significant effect of age, odds for complication among patients with sealant usage were 6.67 times those for patients without sealant. Adjusted for the significance of sealant usage, there is a 6% increase in odds for complication for every year increase in patient's age.

CONCLUSIONS

A statistically significant relationship exists between age and sealant use and the risk of developing a postoperative pseudomeningocele. Emphasis and attention must be placed on meticulous closure technique. This information can aide in preoperative planning and patient selection.

Pediatric and adult Chiari malformation Type I surgical series 1965-2013: a review of demographics, operative treatment, and outcomes

OBJECT

Chiari malformation Type I (CM-I) is a hindbrain disorder associated with elongation of the cerebellar tonsils, which descend below the foramen magnum into the spinal canal. It occurs in children and adults. Clinical symptoms mainly develop from alterations in CSF flow at the foramen magnum and the common subsequent development of syringomyelia.

METHODS

The authors reviewed English-language reports of pediatric, adult, and combined (adult and pediatric) surgical series of patients with CM-I published from 1965 through August 31, 2013, to investigate the following: 1) geographical distribution of reports; 2) demographics of patients; 3) follow-up lengths; 4) study durations; 5) spectrum and frequency of surgical techniques; 6) outcomes for neurological status, syrinx, and headache; 7) frequency and scope of complications; 8) mortality rates; and 9) differences between pediatric and adult populations. Research and inclusion criteria were defined, and all series that contained at least 4 cases and all publications with sufficient data for analysis were included.

RESULTS

The authors identified 145 operative series of patients with CM-I, primarily from the United States and Europe, and divided patient ages into 1 of 3 categories: adult (>18 years of age; 27% of the cases), pediatric (≤18 years of age; 30%), or unknown (43%). Most series (76%) were published in the previous 21 years. The median number of patients in the series was 31. The mean duration of the studies was 10 years, and the mean follow-up time was 43 months. The peak ages of presentation in the pediatric studies were 8 years, followed by 9 years, and in the adult series, 41 years, followed by 46 years. The incidence of syringomyelia was 65%. Most of the studies (99%) reported the use of posterior fossa/foramen magnum decompression. In 92%, the dura was opened, and in 65% of these cases, the arachnoid was opened and dissected; tonsillar resection was performed in 27% of these patients. Postoperatively, syringomyelia improved or resolved in 78% of the patients. Most series (80%) reported postoperative neurological outcomes as follows: 75% improved, 17% showed no change, and 9% experienced worsening. Postoperative headaches improved or resolved in 81% of the patients, with a statistical difference in favor of the pediatric series. Postoperative complications were reported for 41% of the series, most commonly with CSF leak, pseudomeningocele, aseptic meningitis, wound infection, meningitis, and neurological deficit, with a mean complication rate of 4.5%. Complications were reported for 37% of pediatric, 20% of adult, and 43% of combined series. Mortality was reported for 11% of the series. No difference in mortality rates was seen between the pediatric and adult series.

CONCLUSIONS

Before undergoing surgical treatment for CM-I, symptomatic patients and their families should be given clear information about the success of treatment and potential complications. Furthermore, surgeons may benefit from comparing published data with their own. In the future, operative CM-I reports should provide all details of each case for the purpose of comparison.

Management of postoperative pseudomeningoceles: an international survey study

BACKGROUND

Pseudomeningoceles are common complications after posterior fossa and intradural spinal surgery and are often asymptomatic. Management guidelines are lacking, and anecdotally, we have encountered radically different suggested treatments varying from observation to immediate surgical intervention. The goal of this study was to determine the prevailing opinions among neurosurgeons on the management of this condition.

METHODS

Neurosurgeons from around the world were invited via an International Society for Pediatric Neurosurgery (ISPN) and Neurosurgery ListServ e-blast to participate in a 33-question survey on the management of pseudomeningoceles, presented as simulated scenarios after posterior fossa and spinal intradural surgery.

RESULTS

Two hundred forty-one responses were obtained. Pseudomeningoceles after posterior fossa tumor resection, in the absence of hydrocephalus, were typically managed nonoperatively for 7 to 14 days before re-exploration. Only 0.5 % of the surgeons would offer upfront repair of the pseudomeningocele. In the presence of hydrocephalus, 48 % of the neurosurgeons intervene initially with cerebrospinal fluid (CSF) diversion and would change therapy if the lesion did not resolve in 2 to 4 days. Ninety percent of the surgeons manage spinal pseudomeningoceles nonoperatively for 7-14 days before re-exploration is considered. The most common steps taken to prevent pseudomeningoceles are watertight closure, tissue glues, and duroplasty.

CONCLUSION

The present zeitgeist suggests that, in the absence of hydrocephalus, initial observation is appropriate for cranial and spinal pseudomeningoceles. Operative revision should be reserved for failure of conservative treatment. If hydrocephalus is present, consideration should be made for CSF diversion. This study may serve as a guideline regarding acceptable management.

Evaluation of complication rates of pediatric cranial procedures in which a polyethylene glycol sealant was used

OBJECT

Polyethylene glycol (PEG) sealant in conjunction with standard closure techniques is effective in preventing CSF leaks after cranial procedures in adult patients, but the safety of PEG sealant in the pediatric population has not been shown.

METHODS

The authors performed a retrospective analysis of pediatric neurosurgery patients (0-18 years of age) treated from 2005 to 2010 at The Johns Hopkins Hospital. There were 163 patients who underwent cranial surgery with the use of PEG sealant as an adjunct to standard closure techniques. There were 92 males and 71 females with an average age of 10.2 years. The incidences of revision surgery, CSF leak, meningitis, and neurological deficit were recorded.

RESULTS

In the cohort's 90-day postoperative clinical course, the authors found that 4 patients (2.5%) required revision surgery, 2 patients (1.2%) developed a CSF leak, 4 patients (2.5%) developed a superficial skin infection, and 1 patient developed meningitis (0.6%) with no deaths or neurological deficits observed.

CONCLUSIONS

PEG sealant appears to be a safe adjunct to standard dural closure in pediatric cranial surgery patients to augment dural closure.

Surgical outcomes after posterior fossa decompression with and without duraplasty in Chiari malformation-I

INTRODUCTION

Chiari malformation-I (CM) is one of the most controversial entities in the contemporary neurosurgical literature. Posterior fossa decompression (PFD) is the preferred treatment for CM with and without syringomyelia. A variety of surgical techniques for PFD have been advocated in the literature. The aim of this study was to evaluate our results of surgically treated patients for CM-I with and without syringomyelia; using extradural dura-splitting and intradural intraarachnoid techniques.

METHODS

A retrospective review of the medical records of all the patients undergoing PFD was conducted. Symptomatic patients with tonsillar herniation≥3-mm below the foramen magnum on neuroimaging, and CSF flow void study demonstrating restricted or no CSF flow at the craniocervical junction, were offered surgical treatment. In patients without syringomyelia, extradural decompression with thinning of the sclerotic tissue at the cervicomedullary junction and splitting of outer dural layer was performed. In patients with syringomyelia, the dura was opened and an expansile duraplasty was performed.

RESULTS

The mean age of 8 males and 34 females was 33.8 years (range, 16-58 years). Headache (39/41; 95%), and/or tingling and numbness (17/41; 42%) were the most common presenting symptoms. The syrinx was associated with CM-I in 5/41 (12%) patients. PFD without durotomy was performed in 29/41 (73%) patients. The mean duration of preoperative symptoms was significantly longer in duraplasty group (4.6 versus 1.7 years, P=0.005, OR=0.48, CI=0.29-0.8). The use of duraplasty was significantly associated with presence of complications (P=0.004, OR=0.5, CI=0.3-0.8) and longer duration of hospital stay (P=0.03, OR=2.7, CI=1.1-6.8). The overall complication rate was 6/41(15%) patients. The overall improvement rate was evident in 84% (36/41); 12% (5/41) were stable; and 5% (2/41) had worsening of symptoms. The history of prior CM decompression was associated with unfavorable outcomes (P=0.04, OR=14, CI=1.06-184). One patient experienced recurrence one year after the PFD with duraplasty.

CONCLUSION

The present study reports favorable surgical outcomes with extra-dural decompression of the posterior fossa in patients CM-I without syringomyelia. For patients with syringomyelia and history of prior PFD, intradural intra-arachnoid decompression is required. The prior history of decompression was associated with unfavorable outcomes. The use of duraplasty was associated with longer duration of hospital stay and higher complication rate. Further large cohort prospective study is needed to provide any recommendation on the indication of intra or extradural decompression for a given CM-I patient.