Comparison of dural grafts in Chiari decompression surgery: Review of the literature

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.

Chiari Type I Revision Decompressive Surgery Indications and Operative Technique: Experience in a Large Adult Cohort

BACKGROUND

Chiari malformation is characterized by inferior displacement of the cerebellar tonsils through the foramen magnum, frequently resulting in strain related headaches, and motor/sensory dysfunction. Chiari decompression technique varies significantly, possibly contributing to frequent revisions. We reviewed revision Chiari decompressions at our institution to determine the primary indications for revision and outcomes after revision.

METHODS

We retrospectively reviewed patients who underwent revision of Chiari decompression at our institution from 2005 to 2020. Demographics, indications for revision surgery, operative techniques, imaging findings, and preoperative/postoperative symptoms were collected. χ2 test was performed to determine statistical significance using a P < 0.05. Independent predictors of operative outcomes were identified.

RESULTS

A total of 46 patients (91% females, mean age 38.8 years) were included for analysis. The median time to revision surgery was 69.1 months (range 0-364 months) with headache (n = 37, 80%) being the most commonly recurring symptom. Large craniectomy (n = 28, 61%) was the most frequent indication for revision surgery. Thirty-two (70%) patients underwent cranioplasty, 20 (43%) required duraplasty, 15 (33%) required arachnoid dissection, and 15 (33%) required tonsillar reduction during revision surgery. Postrevision follow-up (at 8.9 ± 5.2 months average, range 1-18 months), revealed an average reduction in all Chiari-related symptoms relative to symptoms before the revision.

CONCLUSIONS

The most common indication for revision Chiari decompression was a large craniectomy resulting in cerebellar ptosis. We found that tonsillar reduction paired with modest craniectomy achieved near-complete resolution of symptoms with minimal complications. For patients with recurrent or persistent sequelae of Chiari malformation after decompression, revision may reduce symptom severity.

Bovine Pericardium Treated with Polyethylene Glycol and Ethanol Versus Pericranium for Duraplasty: A Pilot Study in Supratentorial Neurosurgery

BACKGROUND

Watertight closure of dura mater after intracranial surgery can avoid cerebrospinal fluid leakage and central nervous system infection and herniation. When primary closure is not possible, the pericranium is the preferential choice. When it is not available, a dural substitute becomes necessary. Bovine pericardium treated with polyethylene glycol and ethanol is herein tested as a dural substitute.

METHODS

A pilot study comparing bovine pericardium with pericranium in supratentorial neurosurgery was performed.

RESULTS

Twenty patients were initially allocated into a bovine pericardium group (group 1) or a pericranium group (group 2). Three patients from group 1 and 2 from group 2 had a loss of follow-up, being excluded. In the remaining 15 patients, epidemiological analysis demonstrated a male:female ratio of 3:4 and 4:4 for groups 1 and 2. Ages varied from 28 to 68 (Mean = 49.6) in group 1 and 40-80 (Mean = 61.2) in group 2, with a mean difference of 11.68 years (P = 0.09). Two cases of surgical site infection and 1 of hydrocephalus were observed. Although the calculated relative risk for complications was higher in group 1 (Relative Risk = 1.08), Fisher exact test demonstrated no statistically significant difference between groups (P = 1.00). Procedure mean time was 23 minutes and 11 seconds in group 1 versus 27 minutes and 55 seconds in group 2 (P = 0.47). Mean graft area was 13.17 and 6.23 cm2 in groups 1 and 2 (P = 0.02).

CONCLUSIONS

Bovine pericardium treated with polyethylene glycol and ethanol was comparable to pericranium as a dural substitute. More studies are encouraged to certify our findings.

Delta Cord as a Radiological Localization Sign of Postoperative Adhesive Arachnoiditis: A Case Report and Literature Review

Postoperative adhesive arachnoiditis is an inflammatory response of the spinal leptomeninges that occurs after surgery and results in scar formation in the avascular nature of the arachnoid layer. Clinical manifestations of postoperative adhesive arachnoiditis include pain, sensory deficits, motor dysfunction, reflex abnormalities, and bladder or bowel impairment. In magnetic resonance imaging scans, signs of postoperative adhesive arachnoiditis can vary; however, some indicators can assist surgeons in locating the lesion accurately and, thus, in planning effective surgical interventions. This paper reports the case of a 37-year-old man with postoperative adhesive arachnoiditis after two surgeries for Chiari I malformation. This case illustrates the progressive development of the "delta cord sign", which refers to the formation of a thick arachnoid band causing the spinal cord to adopt a triangular shape in the axial view. This phenomenon is accompanied by the sequential occurrence of syringomyelia. During intraoperative examination, we identified the presence of the delta cord sign, which had been formed by an arachnoid scar that tethered the dorsal spinal cord to the dura. This discovery enabled us to precisely pinpoint the location of the arachnoid scar and thus provided us with guidance that enabled us to avoid unnecessary exploration of unaffected structures during the procedure. Other localization signs were also reviewed.

Dual Dural Patch Graft With AlloDerm and DuraGen Underlay for Duraplasty in Chiari Malformation Results in Significantly Decreased Cerebrospinal Fluid Leak Complications

BACKGROUND

Grafts available for posterior fossa dural reconstruction after Chiari decompression surgery include synthetic, xenograft, allograft, and autograft materials. The reported rates of postoperative pseudomeningocele and cerebrospinal fluid leak vary, but so far, no dural patch material or technique has sufficiently eliminated these problems.

OBJECTIVE

To compare the incidence of graft-related complications after posterior fossa surgery using AlloDerm alone vs AlloDerm with a DuraGen underlay.

METHODS

We performed a retrospective single-center study of a cohort of 106 patients who underwent Chiari decompression surgery by a single surgeon from 2014 through 2021. Age, sex, body mass index, tonsillar descent, syrinx formation, type of dural graft, and follow-up data were analyzed using univariate and χ2 statistical tests.

RESULTS

The AlloDerm-only group had a percutaneous cerebrospinal fluid (CSF) leak rate of 8.6% vs a 0% rate in the dual graft group (P = .037). At initial follow-up, there was a 15.5% combined rate of pseudomeningocele formation plus CSF leak in the AlloDerm-only group vs 18.8% in the AlloDerm + DuraGen group (P = .659). However, the pseudomeningoceles were larger in the AlloDerm-only cohort (45.5 vs 22.4 mm anteroposterior plane, P = .004), and 5 patients in this group required operative repair (56%). All pseudomeningoceles resolved without reoperation in the AlloDerm + DuraGen group (P = .003).

CONCLUSION

The use of a DuraGen underlay with a sutured AlloDerm dural patch resulted in significantly fewer CSF-related complications and eliminated the need for reoperation compared with AlloDerm alone. This single-center study provides evidence that buttressing posterior fossa dural grafts with a DuraGen underlay may decrease the risk of postoperative complications.

Duraplasty with autologous nuchal ligament fascia to reduce postoperative complications in pediatric patients undergoing neoplasia resection with a suboccipital midline approach

OBJECTIVE

The authors sought to explore the safety and efficacy of an autologous nuchal ligament for dural repair in pediatric patients undergoing tumor resection through a suboccipital midline approach.

METHODS

Pediatric patients diagnosed with posterior fossa neoplasia who underwent surgery through a suboccipital midline approach were retrospectively reviewed. The patients were divided into artificial graft and autograft groups according to whether artificial duraplasty material or autologous nuchal ligament was used to repair the dura. Postoperative complications were reviewed and analyzed, including CSF leak, pseudomeningocele, and meningitis, during hospitalization and follow-up. Univariate and multivariate logistic regression analyses were used to investigate the relationship between duraplasty material and postoperative complications, as well as other risk factors for postoperative complications. Furthermore, multinomial logistic regression analysis was used to clarify which postoperative complications the autologous nuchal ligament tended to reduce.

RESULTS

This retrospective study included 66 pediatric patients who underwent tumor resection through a suboccipital midline approach. The clinical baseline characteristics were comparable between the two groups. The results showed that the autograft group had significantly fewer postoperative complications, especially pseudomeningocele, compared with the artificial graft group. Moreover, the time required to repair the dura in the autograft group was significantly less than that in the artificial graft group. Further results revealed that the duraplasty material, ependymoma, preoperative severe hydrocephalus requiring an external ventricular drain (EVD), and postoperative hydrocephalus exacerbation were independent risk factors for postoperative complications. In particular, the autologous fascia of the nuchal ligament tended to reduce pseudomeningocele more than CSF leak and meningitis. However, compared with pseudomeningocele and CSF leak, both ependymoma and postoperative hydrocephalus exacerbation were more likely to increase the occurrence of meningitis. In contrast, preoperative severe hydrocephalus requiring EVD led to increased rates of postoperative complications.

CONCLUSIONS

For pediatric patients with intracranial tumors who need to undergo resection through a suboccipital midline approach, dural repair using the nuchal ligament is safe, cost-effective, and time saving and significantly reduces postoperative complications.

Comparison between Dura-Splitting Technique with Duraplasty in Symptomatic Patients with Chiari Malformation Type I: A Systematic Review and Meta-analysis

BACKGROUND: There are many surgical procedures for CIM patients, posterior fossa decompression with fibrous band excision, with additional duraplasty, or syringosubdural shunt for syringomyelia related CIM. Prospective studies have been carried out but yet no conclusion, on which one is the best option. The objective of this study was to assess qualitatively the outcome of posterior fossa decompression with dura-splitting (PFDDS) technique compared to posterior fossa decompression with duraplasty (PFDDP) for treating CIM patients. AIM: This study aimed to give us a preference while conducting surgery in a patient with Chiari malformation type I (CIM) between posterior fossa decompression with incision of the fibrous band of the dura (dura-splitting/DS) technique and duraplasty (DP) technique. METHODS: The analysis conducted using PRISMA flowchart with PICO framework (Patient: Chiari malformation type I patient over preschool age; Intervention: Dura-splitting; Comparison: Duraplasty; and Outcome: Complication rate, length of stay, reoperation rate, syrinx reduction, symptomatic improvement, and operation time) and already registered for meta-analysis study with database searching from PubMed, the Cochrane Library, and Google Scholar that following inclusion criteria: (1) Original study; (2) study that compares DS and DP in CM- I; and (3) patient age over preschool age. RESULTS: A review of five included studies involving 458 patients met the inclusion criteria, in which 319 patients treated with DS surgery and 139 for DP surgery for this study. Significantly DS technique correlated lower rate of complication (RR = 0.20; p < 0.0001), shorter length of stay (MD = −3.53; p = 0.0002), and shorter operation time (MD = −58.59; p = 0.0004). No significant differences in reoperation rate (RR = 1.90; p = 0.22), symptom improvement (RR = 1.12; p = 0.44), and syrinx reduction (RR = 1.11; p = 0.56) were noted. CONCLUSIONS: Posterior fossa decompression using the DS technique is associated with a lower rate of complication, shorter length of stay, and shorter operation time. However, no significant differences were found in the reoperation rate, symptom improvement, and syringomyelia reduction between these two techniques.

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.

Complication Avoidance in Surgical Management of Vertebral Column Tumors

The surgical management of spinal tumors has grown increasingly complex as treatment algorithms for both primary bone tumors of the spine and metastatic spinal disease have evolved in response to novel surgical techniques, rising complication rates, and additional data concerning adjunct therapies. In this review, we discuss actionable interventions for improved patient safety in the operative care for spinal tumors. Strategies for complication avoidance in the preoperative, intraoperative, and postoperative settings are discussed for approach-related morbidities, intraoperative hemorrhage, wound healing complications, cerebrospinal fluid (CSF) leak, thromboembolism, and failure of instrumentation and fusion. These strategies center on themes such as pre-operative imaging review and medical optimization, surgical dissection informed by meticulous attention to anatomic boundaries, and fastidious wound closure followed by thorough post-operative care.

Dural tear repair surgery comparative analysis: a stitch in time saves nine

PURPOSE

A dural tear is a common iatrogenic complication of spinal surgery associated with a several post-operative adverse events. Despite their common occurrence, guidelines on how best to repair the defect remain unclear. This study uses five post-operative outcomes to the compare repair methods used to treat 106 dural tears to determine which method is clinically favourable.

METHODS

Data were retrospectively collected from Southampton General Hospital's online databases. 106 tears were identified and grouped per repair method. MANOVA was used to compare the following five outcomes: Length of stay, numbers of further admissions or revision surgeries, length of additional admissions, post-operative infection rate and dural tear associated neurological symptoms. Sub-analysis was conducted on patient demographics, primary vs non-primary closure and type of patch. Minimal clinically important difference (MCID) was calculated via the Delphi procedure.

RESULTS

Age had a significant impact on patient outcomes and BMI displayed positive correlation with three-fifth of the predefined outcome measures. No significant difference was observed between repair groups; however, primary closure ± a patch achieved an MCID percentage improvement with regards to length of original stay, rate of additional admissions/surgeries and post-operative infection rate. Artificial over autologous patches resulted in shorter hospital stays, fewer readmissions, infections and neurological symptoms.

CONCLUSION

This study reports primary closure ± dural patch as the most efficient repair method with regards to the five reported outcomes. This study provides limited evidence in favour of artificial over autologous patches and recommends that dural patches be used in conjunction with primary closure.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

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.

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.

Comparison of dural grafts and methods of graft fixation in Chiari malformation type I decompression surgery

Suboccipital decompression with duraplasty is a widely accepted method for treating patients with Chiari malformation type I. However, important details of the duraplasty technique are still controversial. This retrospective study analyzes clinical and radiological outcomes after surgery depending upon the type of graft and methods of graft fixation. Seventy consecutive decompressions with duraplasty were analyzed. Two types of grafts, nonautologous (Non-AutoG; 60.0%) and autologous (AutoG; 40.0%), and two methods of graft fixation, suturing (S; 67.1%) and gluing (G; 32.9%), were used in four different combinations: (Non-AutoG+S: 31.4%; Non-AutoG+G: 28.6%; AutoG+S: 35.7%; AutoG+G: 4.3%) according to surgeon preference. The mean follow-up was 63.4 months. According to gestalt and Chicago Chiari Outcome Scales, satisfactory results were obtained in 72.9% and 78.6% of cases, respectively, in the long term. The outcomes were not related to the kind of graft (p = 0.44), fixation method (p = 0.89) or duraplasty pattern (p = 0.32). Decreased syringomyelia was observed in 88.9% of cases, and no associations with the kind of graft (p = 0.84), fixation method (p = 1) or duraplasty pattern were found (p = 0.96). Pseudomeningocele occurred 5 times more often in the Non-AutoG group than in the AutoG group (52.4% vs. 10.7%; p < 0.05), whereas their formations were not related to the fixation method (p = 0.34). Three cases (12.0%) required reoperation with reduraplasty. Autologous and nonautologous dural grafts can be sutured or glued with similar clinical results; however, the use of nonautologous grafts is linked with a much higher risk of pseudomeningocele formation.

Extradural abscess following synthetic fabric duraplasty

Background:

Duraplasty refers to the neurosurgical process of reconstructing dural defect. Variety of materials is used for such reconstruction, including natural, semisynthetic, and synthetic materials. Although synthetic materials are readily available and easy to apply, these are associated with foreign body reaction which may lead to serious consequences in some cases. We describe one such rare instance of extradural abscess after polypropylene synthetic fabric duraplasty.

Case Description:

Our patient is a 33-year-old lady who suffered road traffic accident leading to massive brain laceration, contusion of bilateral frontal lobes, and anterior skull base fractures. Emergency craniotomy was carried out and dural defect repaired with polypropylene (G-Patch; G. Surgiwear^® Ltd.) synthetic fabric as the duraplasty material. Three months later, the patient presented with discharging wound at the incision site. Neuroimaging showed ring enhancing lesion in frontobasal extradural space with cutaneous extension. The lesion failed to heal despite intravenous antibiotics and surgery was planned. Intraoperatively, abscess was found between G-Patch and dura. Histopathology showed granulomatous foreign body reaction. The lesion healed after synthetic dura removal and abscess drainage.

Conclusion:

Although various materials are used for duraplasty, there is no clear consensus on what material should be used for dural repair. Synthetic materials are bio-inert, offer good handling and malleability. Polypropylene has been used safely for both single- and double-layered duraplasty. However, foreign body reaction may occur and very rarely present as extradural abscess. Randomized trials should be done to establish the safety and efficacy profile of commonly used duraplasty materials.

Comparison of two surgical techniques in Chiari Malformation Type 1 Patients: Duraplasty alone vs duraplasty with arachnoid dissection

OBJECT

Optimal surgical technique to restore the cerebrospinal fluid flow through the foramen magnum remains to be debated in Chiari malformation type 1 (CM-1) patients.

METHOD

This study included 46 patients with CM-1 who underwent surgical treatment by one of two methods: posterior fossa bone decompression (BD) with arachnoid preserving duraplasty (Group 1) and BD with duraplasty and arachnoid dissection (Group 2). Complaints of the patient population and neurological findings were assessed with Neck Disability Index (NDI) and Europe Quality of Life 5 Dimensions (EQ-5D) in pre- and postoperative periods.

RESULTS

NDI and EQ-5D scores improved in overall patient population and in each individual surgical group. Both groups showed a significant decrease in size of syringomyelia cavity. Complications resulting in recurrent treatments and re-operations occurred in 15% of patients (n = 7); six of them were from Group 2.

CONCLUSION

CM-1 patients benefit significantly from surgical treatment. Duraplasty should be included to surgical technique. Avoiding arachnoid dissection may lead to better results regarding complication rates.

Asymptomatic superficial siderosis after posterior fossa tumor resection: illustrative case

BACKGROUND

Superficial siderosis of the central nervous system is a rare syndrome notable for the presence of hemosiderin deposition due to chronic, repetitive hemorrhages into the subarachnoid space.

OBSERVATIONS

The authors presented a case of superficial siderosis in a 14-year-old girl. It arose as a late postoperative complication after resection of a medulloblastoma. Despite the patient being asymptomatic, surveillance imaging demonstrated diffuse hemosiderin deposition within the cerebellar folia and cisternal segments of cranial nerves VII and VIII on gradient echo (GRE) sequences. Formal audiometric testing demonstrated bilateral loss of high-frequency tone recognition consistent with early sensorineural hearing loss. A pseudomeningocele due to multiple dural defects was identified as the likely cause, and definitive surgical repair was performed. Intraoperatively, the presence of blood-tinged cerebrospinal fluid confirmed a diagnosis of superficial siderosis.

LESSONS

This case highlighted the potential need to routinely include GRE or susceptibility-weighted sequences in postoperative surveillance imaging after resection of pediatric posterior fossa tumors.

Applications of materials for dural reconstruction in pre-clinical and clinical studies: Advantages and drawbacks, efficacy, and selections

The dura mater provides a barrier to protect the tissue underneath and cerebrospinal fluid. However, dural defects normally cause cerebrospinal fluid leakage and other complications, such as wound infections, meningitis, etc. Therefore, the reconstruction of dura mater has important clinical significance. Current dural reconstruction materials include: homologous, acellular, natural, synthetic, and composite materials. This review comprehensively summarizes the characteristics and efficacy of these dural substitutes, especially in clinical applications, including the advantages and drawbacks of those from different sources, the host tissue response in pre-clinical studies and clinical practice, and the comparison of these materials across different surgical procedures. Furthermore, the selections of materials for different surgical procedures are highlighted. Finally, the challenges and future perspectives in the development of ideal dural repair materials are discussed.

Professional Profiles, Technical Preferences, Surgical Opinions, and Management of Clinical Scenarios from a Panel of 63 International Experts in the Field of Chiari I Malformation

BACKGROUND

Chiari I Malformation (CMI) and the topics concerning it have been the subject of numerous discussions and polarizing controversies over the course of the past 20 years.

METHODS

The opinions of 63 recognized international Neurosurgical CMI experts from 4 continents, with a collective surgical experience of more than 15,000 CMI cases, were gathered through a detailed questionnaire, divided in two parts: diagnostic and therapeutic. The therapeutic part was organized into four sections: Professional Profile, Technical Preferences, Surgical Opinions, and Clinical Scenarios.

RESULTS

The data reflected a wide spectrum of opinions, approaches, and expertise. The second part of the questionnaire dealt with the surgical aspects of CMI care and painted a more complex picture: • 81% of the surgeons preferred the Intradural technique. • 88% of the experts agreed that CMI surgery is not indicated for minimal non-debilitating symptoms alone, or as prophylaxis. • In the face of given clinical scenarios, a wide spectrum of therapeutic approaches was chosen by the whole group, but the 4 Surgeons with the largest case series expressed the same opinion. • Eight out of 63 Surgeons had a surgical experience above 600 cases, were responsible for more than half of the total 15,000 declared CMI cases, and shared a similar profile in terms of technical surgical choices, therapeutic opinions, and low complication rate, with a marked preference for Intradural techniques and tonsillar manipulation. • Once large individual case series were accumulated, we did not see any differences in the opinions and preferences between Adult and Pediatric Neurosurgeons.

CONCLUSION

Surgeons who have focused on CMI have been able to accumulate large surgical series, have chosen in their practices the more aggressive (and intrinsically more effective) CMI surgical techniques, and have achieved a low complication rate which compares favorably with that one of the extradural techniques.

Duraplasty with Cervical Fascia Autograft to Reduce Postoperative Complications of Posterior Fossa Tumor Surgery with Suboccipital Midline Approach

BACKGROUND

The suboccipital midline approach is common dealing with posterior fossa tumors but has a high risk of postoperative complications, such as pseudomeningocele, cerebrospinal fluid (CSF) leak, and meningitis. Neurosurgeons used various kinds of method to lower its rate.

METHODS

A retrospective, single-center review of patients diagnosed with posterior fossa tumor underwent a suboccipital midline approach. Compare the rates of pseudomeningocele, CSF leak, and meningitis between 2 groups (artificial dura mater or cervical fascia autograft). We get the cervical fascia autograft from the superficial layer of deep cervical fascia just above the trapezius.

RESULTS

Our retrospective review involved 123 patients matching the inclusion criteria between January 2009 and April 2019. The complication rate of pseudomeningocele, CSF leak and meningitis were 8.9%, 4.9%, and 17.9%, respectively. The presence of pseudomeningocele or CSF leak for group "artificial" was 11 of 75 (14.67%) and for group "autograft" it was 3 of 48 (6.25%). The rate of meningitis for group "artificial" (24.0%, 18 of 75) was significantly higher (P = 0.027) than the one for group "autograft" (8.33%, 4 of 48). Multivariate regression analysis suggested that the age was negatively correlated with postoperative pseudomeningocele or CSF leak (P = 0.006), with meningitis (P < 0.001). Using cervical fascia autograft decreased the rate of meningitis (P = 0.021) while showing no statistically significant clinical impact on pseudomeningocele or CSF leak.

CONCLUSIONS

Applying the cervical fascia autograft to reconstruct the dura during posterior fossa surgery is a simple and effective method to reduce the rate of meningitis as compared with artificial dura mater.

The use of dehydrated amniotic membrane allograft for augmentation of dural repair in transsphenoidal endoscopic endonasal resection of pituitary adenomas

BACKGROUND

In transsphenoidal endoscopic endonasal surgery (TEES), watertight separation of the sinonasal cavity and intracranial compartment is the primary goal of closure. However, even when meticulous closure technique is implemented, cerebrospinal fluid (CSF) leaks, dural scarring, and meningitis may result. Particularly when intraoperative CSF leak occurs, materials that facilitate the creation of a watertight seal that inhibits disease transition and minimizes inflammatory response after durotomy are sought. Dehydrated amniotic membrane (DAM) allograft appears to confer these attributes as studies have shown it augments epithelialization, facilitates wound healing, and minimizes and impedes bacterial growth. We detail the use of DAM allograft to augment sellar closures after TEES.

METHODS

We conducted a feasibility study, retrospectively reviewing our institution's database of TEES for resection of pituitary adenomas in which DAM was utilized to supplement sellar closure.

RESULTS

One hundred twenty transsphenoidal surgery cases with DAM were used during sellar closure, with a 49.2% intraoperative CSF leak rate. Of this cohort, two patients experienced postoperative CSF leak (1.7%), and no patients developed meningitis. CSF leak rate for TEES-naïve patients was 0.9%.

CONCLUSIONS

This feasibility study demonstrates that dehydrated amniotic membrane allograft can be safely utilized as an adjunct during sellar closures for TEES for pituitary adenoma resection with very low rates of CSF leak and meningitis.

Human Amniotic Membrane for the Prevention of Intradural Spinal Cord Adhesions: Retrospective Review of its Novel Use in a Case Series of 14 Patients

BACKGROUND

Tethering after spinal surgery is caused by adhesions that arise from intradural tissue manipulation. Microsurgical detethering is the only treatment for symptomatic patients, but retethering occurs commonly and no treatment is widely available to prevent this complication.

OBJECTIVE

To apply human amniotic membrane (HAM) grafts, which are immune-privileged and known to possess antifibrogenic properties, in patients requiring microsurgical detethering. For this first-in-human use, we evaluated the safety and potential efficacy of these grafts for preventing retethering.

METHODS

We retrospectively reviewed the medical records of all patients who required detethering surgery and received an HAM graft between 2013 and 2016 at our institution after various previous intradural spinal surgeries. In all 14 cases, intradural lysis of adhesions was achieved, an HAM graft was sewn in place intradurally, and a dural patch was closed in a watertight fashion over the graft.

RESULTS

Fourteen patients had received HAM grafts to prevent retethering. All patients had at least 6 mo of follow-up (mean follow-up, 14 mo). Retethering was noted in only 1 patient. Surgical re-exploration showed that the retethering occurred caudal to the edge of the HAM graft, with no tethering underneath the original graft. No complications were attributed specifically to the HAM graft placement.

CONCLUSION

This first-in-human series provides evidence that HAM grafts are a safe and potentially efficacious method for preventing retethering after microsurgical intradural lysis of adhesions. These results lay the groundwork for further prospective controlled trials in patients with this difficult-to-treat pathology.

Hydrocephalus after foramen magnum decompression for Chiari I malformation successfully treated with the aspiration of pseudomeningocele: a case report

Background

Pseudomeningocele or cerebrospinal fluid leakage is one of the most common complications of foramen magnum decompression with duraplasty for Chiari I malformation. Usually, cerebrospinal fluid leakage is treated with lumbar drainage and/or secondary suture. However, if hydrocephalus occurs, spinal drainage may cause brain herniation.

Case presentation

A 54-year-old Japanese woman presented to our hospital with a 10-month history of bilateral finger extension weakness and clumsiness. Magnetic resonance imaging showed displacement of her cerebellar tonsils below the foramen magnum level, with syringomyelia presenting from the C4 to T8 level. Suboccipital craniectomy and C1 laminectomy with duraplasty were performed under general anesthesia. At 1 month after discharge, she again presented to our hospital due to severe headache and nausea. Magnetic resonance imaging of her cervical spine showed pseudomeningocele compressing her cerebellum and spinal cord. Magnetic resonance imaging of her brain also showed ventriculomegaly. Pseudomeningocele aspiration was performed, with 25 ml of fluid removed under X-ray control. Immediately after aspiration her headache and nausea decreased, and she reported improvement in her symptoms with increasing bilateral finger extension strength and decreasing bilateral upper extremity numbness at her 1-year follow-up.

Conclusions

Although there is a considerable risk of meningitis with the aspiration procedure of pseudomeningocele, an aspiration procedure may be an easy and effective treatment option for postoperative hydrocephalus after suboccipital craniotomy with duraplasty in a patient treated for Chiari I malformation.

Heterotopic ossification following suboccipital craniectomy decompression surgery for Chiari malformation type I: case report

Suboccipital craniectomy with duraplasty is a commonly performed procedure for children with symptomatic Chiari malformation type I (CM-I). Several dural substitutes are used for duraplasty, ranging from pericranium to synthetic materials. When available, autologous pericranium is often preferred due to its low cost, performance in obtaining a watertight closure, ease of suturing, and absence of immune reaction. Long-term follow-up data on the durability of various dural substitutes are lacking. The authors report a rare, long-term complication of duraplasty performed using an autologous pericranial graft, and they conduct a literature review of similar complications. Heterotopic ossification of an autologous pericranial graft is a rare complication of duraplasty. This dystrophic bone growth can be symptomatic due to compression of neural structures, and it requires reoperation for removal. Surgeons should consider this rare long-term complication in patients presenting with unusual symptoms after duraplasty with pericranium.

Chiari I Malformation: Opinions on Diagnostic Trends and Controversies from a Panel of 63 International Experts

BACKGROUND

Chiari I malformation (CMI) and the topics concerning it have been the subject of numerous discussions and polarizing controversies over the course of the last 20 years.

METHODS

The opinions of 63 recognized international CMI experts from 4 continents, with a collective surgical experience of >15,000 CMI cases, were gathered through a detailed questionnaire.

RESULTS

Three facts emerged from the analysis of the results: 1) Most of the replies showed a high level of consensus on most CMI-related topics. 2) Several topics, which had been considered controversial as recently as 10 years ago, are now more widely accepted. 3) The so-called 5-mm rule was rejected by 88.5% of the CMI experts who responded to the questionnaire.

CONCLUSIONS

Sixty three recognized international CMI experts from 4 continents, with a collective surgical experience of >15,000 CMI cases were polled about a number of CMI topics. The results showed a high level of consensus, as well as a paradigm shift.

Cerebrospinal fluid leaks after spine tumor resection: avoidance, recognition and management

Post-operative CSF leaks are a known complication of spine surgery in general, and patients undergoing surgical intervention for spinal tumors may be particularly predisposed due to the presence of intradural tumor and a number of other factors. Post-operative CSF leaks increase morbidity, lengthen hospital stays, prolong immobilization and subject patients to a number of associated complications. Intraoperative identification of unintended durotomies and effective primary repair of dural defects is an important first step in the prevention of post-operative CSF leaks, but in patients who develop post-operative pseudomeningoceles, durocutaneous fistulae or other CSF-leak-related sequelae, early recognition and secondary intervention are paramount to preventing further CSF-leak-related complications and achieving the best patient outcomes possible. In this article, the incidence, risk factors and complications of CSF leaks after spine tumor surgery are reviewed, with an emphasis on avoidance of post-operative CSF leaks, early post-operative identification and effective secondary intervention.

Surgical Treatment in Symptomatic Chiari Malformation Type I: A Series of 25 Adult Patients Treated with Cerebellar Tonsil Shrinkage

BACKGROUND

The variety of symptoms and radiological findings in patients with Chiari malformation type I makes both the indication for surgery and the technical modality controversial. We report our 5-year experience, describing our technique and critically evaluating the clinical results.

METHODS

Between 2012 and 2016, 25 patients (15 female and 10 male; mean age 39.2 years) underwent posterior fossa decompression for Chiari malformation type I. Their clinical complaints included headache, nuchalgia, upper limb weakness or numbness, instability, dizziness and diplopia. Syringomyelia was present in 12 patients (48%). Suboccipital craniectomy was completed in all cases with C1 laminectomy and shrinkage of the cerebellar tonsils by bipolar coagulation; duraplasty was performed with a suturable dura substitute.

RESULTS

Gratifying results were observed in our series. Symptoms and signs were resolved in 52% of patients, and 20% of patients had an improvement in their preoperative deficits. The symptoms of six patients (24%) were essentially unchanged, and one patient (4%) deteriorated despite undergoing surgery. Generally, patients with syringomyelia on magnetic resonance imaging (MRI) showed less symptomatic improvement after surgery. The syrinx disappeared in seven of 12 patients, and complications occurred in three patients (12%).

CONCLUSION

Cerebellar tonsil reduction and restoration of cerebrospinal fluid (CSF) circulation provided clinical improvement and a stable reduction in the syrinx size in the vast majority of treated patients, with a low rate of complications.

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.

Chiari decompression outcomes using ligamentum nuchae harvest and duraplasty in pediatric patients with Chiari malformation type I

OBJECTIVE The choice of graft material for duraplasty in decompressions of Chiari malformations remains a matter of debate. The authors present a detailed technique for harvesting ligamenta nuchae, as well as the clinical and radiographic outcomes of this technique, in a case series. METHODS The authors conducted a retrospective study evaluating the outcomes of Chiari malformation type I decompression and duraplasty in children aged 0-18 years at a single institution from 2013 to 2016. They collected both intraoperative and postoperative variables and compared them qualitatively to published data. RESULTS During the study period, the authors performed 25 Chiari malformation decompressions with ligamentum nuchae graft duraplasties. Of the 25 patients, 10 were females, and the mean age at surgery was 8.6 years (range 13 months to 18 years). The median operative time was 163 minutes (IQR 152-187 minutes), with approximately 10 minutes needed by a resident surgeon to harvest the graft. The mean length of stay was 3 nights (range 2-6 nights), and the mean follow-up was 12.6 months (range 0.5-43.5 months). One patient (4%) developed a CSF leak that was repaired using an oversewing patch. There were no postoperative pseudomeningoceles or infections. Of the 19 patients presenting with a syrinx, imaging showed improvement in 10 (53%) and 8 (42%) had stable syrinx size on imaging. Of 16 patients presenting with a symptomatic Chiari malformation, 14 (87.5%) experienced resolution of symptoms and in 1 (4%) symptoms remained the same. One patient (4%) presented with worsening syrinx and symptoms 1.5 months after initial surgery and underwent repeat decompression. CONCLUSIONS The authors describe a series of clinical and imaging outcomes of patients who underwent Chiari malformation decompression and duraplasty with a harvested ligamentum nuchae. The rates of postoperative CSF leak are similar to established techniques of autologous and artificial grafts, with similarly successful outcomes. Further study will be needed with larger patient cohorts to more directly compare duraplasty graft outcomes.

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.

Cisterna magna arachnoid membrane suturing decreases incidence of pseudomeningocele formation and incisional CSF leakage

OBJECTIVE

A pseudomeningocele and an incisional cerebrospinal fluid leak are considered frequent complications following neurosurgical operations. The rate of these complications especially increases following neurosurgical procedures on the posterior cranial fossae. According to some publications, the rate of pseudomeningoceles has been reported as high as 40%, whereas that of incisional cerebrospinal fluid leaks is up to 17%. For the purposes of reducing the risk of these complications after a midline suboccipital craniotomy, we propose suturing the arachnoid membrane of the cisterna magna. In this paper, we present a retrospective analysis of arachnoid membrane suturing.

METHODS

Seventy patients underwent midline suboccipital craniotomy by the first author between 2012 and 2016 at Burdenko Neurosurgery Institute. In this group was included a consecutive group of patients with posterior fossae tumors where the approach was performed through the cisterna magna arachnoid membrane following midline suboccipital craniotomy and dural opening. The patients were divided into two groups. Group 1 included 38 patients to whom cisterna magna arachnoid membrane suturing was performed with monofilament nonabsorbable suture 7.0., and additionally, the suture was sealed with fibrin adhesive sealant TachoComb®. Group 2 included 32 patients without arachnoid membrane suturing. There was no other significant difference in terms of clinical signs and surgical procedures between these groups. In the postoperative period, the frequency of developing a pseudomeningocele and an incisional cerebrospinal fluid leak was assessed in these two groups. The results were evaluated on the basis of clinical, CT, and MRI data performed in the postoperative period.

RESULTS

In the patients who underwent arachnoid membrane suturing (group I), pseudomeningocele formation was observed in one (2.6%) and CSF leak in one (2.6%) of the 38 patients. In group II, in which patients had no arachnoid membrane suturing, we observed pseudomeningocele formation in 11 (34.4%) patients and a CSF leak in 7 (25.0%) out of 28 patients with known follow-up. Statistical analysis of the data indicates a significantly higher risk of postoperative pseudomeningocele formation and/or an incisional cerebrospinal fluid leak in a group of patients who did not undergo arachnoid membrane suturing (p < 0.05).

CONCLUSIONS

Suturing of the arachnoid membrane of the cisterna magna and its further sealing with fibrin adhesive sealant TachoComb® create an additional barrier for preventing cerebrospinal fluid collection in the extradural space. This technique significantly reduces the risk of postoperative pseudomeningocele formation and/or an incisional cerebrospinal fluid leak in patients with midline suboccipital craniotomy.

Dural Repair in Cranial Surgery Is Associated with Moderate Rates of Complications with Both Autologous and Nonautologous Dural Substitutes

OBJECTIVE

Duraplasty, a common neurosurgical intervention, involves synthetic or biological graft placement to ensure dural closure. The objective of this study is to advance our understanding of the use of dural substitutes in cranial surgery.

METHODS

The PubMed database was systematically searched to identify studies published over the past decade (2007-2017) that described duraplasty procedures. Clinical data were disaggregated and analyzed for the comparisons of biological versus synthetic grafts.

RESULTS

A total of 462 cases were included in the quantitative synthesis. Overall, the most common indication for duraplasty was tumor resection (53%). Allografts were more frequently used in decompression for Chiari malformations compared with xenografts and synthetic grafts (P < 0.001). Xenografts were more frequently used in decompressive hemicraniectomy procedures for evacuation of acute subdural hematomas over allografts and synthetics (P < 0.001). Synthetic grafts were more frequently used in tumor cases than biological grafts (P = 0.002). The cumulative complication rate for dural substitutes of all types was 11%. There were no significant differences in complication rates among the 3 types of dural substitutes.

CONCLUSIONS

Dural substitutes are commonly used to ensure dural closure in a variety of cranial procedures. This study provides greater insight into duraplasty practices and highlights the moderate complication rate associated with the procedure. Future studies are needed to determine the safety and efficacy of such procedures in larger prospective cohorts.

Low complication rate of sellar reconstruction by artificial dura mater during endoscopic endonasal transsphenoidal surgery

To evaluate effect of sellar reconstruction during pituitary adenoma resection surgery by the endoscopic endonasal transsphenoidal approach using artificial cerebral dura mater patch.This was a retrospective study of 1281 patients who underwent endoscopic transsphenoidal resection for the treatment of pituitary adenomas between December 2006 and May 2014 at the Neurosurgery Department of the People's Liberation Army General Hospital. The patients were classified into 4 grades according to intraoperative cerebrospinal fluid (CSF) leakage site. All patients were followed up for 3 months by telephone and outpatient visits.One thousand seventy three (83.7%) patients underwent sellar reconstruction using artificial dura matter patched outside the sellar region (method A), 106 (8.3%) using artificial dura matter patched inside the sellar region (method B), and 102 (8.0%) using artificial dura matter and a mucosal flap (method C). Method A was used for grade 0-1 leakage, method B for grade 1 to 2 leakage, and method C for grade 2 to 3 leakage. During the 3-month follow-up, postoperative CSF leakage was observed in 7 patients (0.6%): 2 among patients who underwent method B (1.9%) and 5 among those who underwent method C (4.9%). Meningitis was diagnosed in 13 patients (1.0%): 2 among patients who underwent method A (0.2%), 4 among those who underwent method B (3.8%), and 7 among those who underwent method C (6.7%).Compared with other reconstruction methods, sellar reconstruction surgery that only use artificial dura mater as repair material had a low rate of complications.

Primary Dural Closure for Retrosigmoid Approaches

Object  Primary closure of posterior fossa dura can be challenging, and postoperative cerebrospinal fluid (CSF) leaks continue to represent a common complication of the retrosigmoid approach. We describe a simple technique to allow for primary closure of the dura following retrosigmoid approaches. The incidence of CSF leaks using this method is reported.

Methods  A retrospective chart review was conducted on all cases of retrosigmoid craniotomies performed by the senior surgeon from February 2009 to February 2015. The primary outcome was development of postoperative CSF leak or pseudomeningocele. Length of stay, lesion type, and other surgical complications were also reported.

Results  Eighty-six patients underwent a retrosigmoid craniotomy during the study period. The most common indications for retrosigmoid craniotomy were microvascular decompression (58%) and tumor resection (36%). No allo- or autografts to repair the dural defect were needed, and no lumbar drains were used. No patients developed CSF otorrhea, rhinorrhea, or incisional leak postoperatively.

Conclusion  Primary dural closure is possible in retrosigmoid approaches without the use of allo- or autografts and may prevent postoperative CSF leaks when combined with other posterior fossa closure techniques. Careful attention to the handling of the dural flap is necessary to achieve this.

Treatment of Syringomyelia in Patients with Arachnoiditis at the Craniocervical Junction

OBJECTIVE

Craniocervical junction arachnoiditis (CCJA) is an uncommon cause of syringomyelia. The pathophysiology of syrinx formation is uncertain, and the appropriate management unclear. A series of cases is reported to demonstrate variations in etiology, uniformity of functional cerebrospinal fluid obstruction at the foramen magnum, and results of surgical intervention.

METHODS

We retrospectively analyzed the clinical and radiologic features of a consecutive series of patients treated for syringomyelia related to CCJA.

RESULTS

Eight patients (5 male, 28-66 years old) were treated from 2000 to 2016. Magnetic resonance imaging demonstrated cervicothoracic syringomyelia in all cases, with the rostral extension of the syrinx suggesting communication with the fourth ventricle in all but one case. There was reduction of foramen magnum cerebrospinal fluid space in all cases, cerebellar ectopia in 5 cases, and fourth ventricular entrapment in 3 cases. Treatment consisted of posterior fossa decompression with either a GoreTex or pericranial patch graft. Six patients had a fourth-ventricle spinal subarachnoid shunt. Two patients had titanium mesh cranioplasty. The immediate postoperative period was associated with reduction in syrinx cavity size and improvement in neurologic symptoms in all cases. At follow-up 10-60 months postoperatively, 3 patients exhibited recurrence of the syrinx and underwent successful reoperation at the craniocervical junction. One patient with persistence of the inferior component of the syrinx was treated with a syrinx-spinal subarachnoid shunt.

CONCLUSIONS

Most syrinx cavities associated with CCJA communicate with the fourth ventricle. Posterior fossa decompression and fourth ventricle to spinal subarachnoid space shunting appears a reasonable treatment for this form of syringomyelia.

Effects of early surgical decompression on functional and histological outcomes after severe experimental thoracic spinal cord injury

OBJECTIVE

In acute traumatic brain injury, decompressive craniectomy is a common treatment that involves the removal of bone from the cranium to relieve intracranial pressure. The present study investigated whether neurological function following a severe spinal cord injury improves after utilizing either a durotomy to decompress the intradural space and/or a duraplasty to maintain proper flow of cerebrospinal fluid.

METHODS

Sixty-four adult female rats (n = 64) were randomly assigned to receive either a 3- or 5-level decompressive laminectomy (Groups A and B), laminectomy + durotomy (Groups C and D), or laminectomy + duraplasty with graft (Group E and F) at 24 hours following a severe thoracic contusion injury (200 kilodynes). Duraplasty involved the use of DuraSeal, a hydrogel dural sealant. Uninjured and injured control groups were included (Groups G, H). Hindlimb locomotor function was assessed by open field locomotor testing (BBB) and CatWalk gait analysis at 35 days postinjury. Bladder function was analyzed and bladder wall thickness was assessed histologically. At 35 days postinjury, mechanical and thermal allodynia were assessed by the Von Frey hair filament and hotplate paw withdrawal tests, respectively. Thereafter, the spinal cords were dissected, examined for gross anomalies at the injury site, and harvested for histological analyses to assess lesion volumes and white matter sparing. ANOVA was used for statistical analyses.

RESULTS

There was no significant improvement in motor function recovery in any treatment groups compared with injured controls. CatWalk gait analysis indicated a significant decrease in interlimb coordination in Groups B, C, and D (p < 0.05) and swing speed in Groups A, B, and D. Increased mechanical pain sensitivity was observed in Groups A, C, and F (p < 0.05). Rats in Group C also developed thermal pain hypersensitivity. Examination of spinal cords demonstrated increased lesion volumes in Groups C and F and increased white matter sparing in Group E (p < 0.05). The return of bladder automaticity was similar in all groups. Examination of the injury site during tissue harvest revealed that, in some instances, expansion of the hydrogel dural sealant caused compression of the spinal cord.

CONCLUSIONS

Surgical decompression provided no benefit in terms of neurological improvement in the setting of a severe thoracic spinal cord contusion injury in rats at 24 hours postinjury. Decompressive laminectomy and durotomy did not improve motor function recovery, and rats in both of these treatment modalities developed neuropathic pain. Performing a durotomy also led to increased lesion volumes. Placement of DuraSeal was shown to cause compression in some rats in the duraplasty treatment groups. Decompressive duraplasty of 3 levels does not affect functional outcomes after injury but did increase white matter sparing. Decompressive duraplasty of 5 levels led to neuropathic pain development and increased lesion volumes. Further comparison of dural repair techniques is necessary.

A novel autologous duraplasty in situ technique for the treatment of Chiari malformation Type I

OBJECTIVE

The purpose of this study was to introduce a novel autologous duraplasty procedure for the treatment of Chiari malformation Type I (CM-I).

METHODS

The authors retrospectively reviewed data from patients who had been diagnosed with CM-I and had undergone suboccipital decompression and autologous duraplasty in situ or synthetic dural graft duraplasty; patients were treated in the authors' department between 2011 and 2014. All procedures were performed by the same surgeon. The 2 duraplasty methods were compared in terms of surgical factors and complications. The authors assessed the neurological outcome and MRI-documented syrinx size at the 6-month follow-up visit.

RESULTS

Twenty-seven patients were enrolled in this study, 13 in the duraplasty in situ group and 14 in the synthetic dural graft duraplasty group. The results showed no significant differences between the duraplasty in situ and synthetic dural graft duraplasty groups in overall operative time (4.9 hours vs 4.1 hours; p = 0.070), estimated blood loss (229 ml vs 254 ml; p = 0.159), and duration of hospital stay after the operation (13.5 days vs 12.8 days; p = 0.808). In the duraplasty in situ group, 1 case of meningitis occurred (7.7%). In the synthetic dural graft duraplasty group, the complications included 1 case of meningitis (7.1%) and 1 CSF leak (7.1%). The mean cost of hospitalization in the duraplasty in situ group (CNY 23,354) was significantly lower than that in the synthetic dural graft duraplasty group (CNY 29,385; p = 0.036).

CONCLUSIONS

Compared with synthetic dural graft duraplasty, autologous duraplasty in situ is a safe, effective, and cost-effective procedure for the treatment of CM-I. The long-term outcome of this procedure requires investigation.

Preservation of the Myofascial Cuff During Posterior Fossa Surgery to Reduce the Rate of Pseudomeningocele Formation and Cerebrospinal Fluid Leak: A Technical Note

Introduction: Suboccipital craniotomy is a workhorse neurosurgical operation for approaching the posterior fossa but carries a high risk of pseudomeningocele and cerebrospinal fluid (CSF) leak. We describe our experience with a simple T-shaped fascial opening that preserves the occipital myofascial cuff as compared to traditional methods to reduce this risk.

Methods: A single institution, retrospective review of prospectively collected database was performed of patients that underwent a suboccipital craniectomy or craniotomy. Patient data was reviewed for craniotomy or craniectomy, dural graft, and/or sealant use as well as CSF complications. A pseudomeningocele was defined as a subcutaneous collection of cerebrospinal fluid palpable clinically and confirmed on imaging. A CSF leak was defined as a CSF-cutaneous fistula manifested by CSF leaking through the wound. All patients underwent regular postoperative visits of two weeks, one month, and three months.

Results: Our retrospective review identified 33 patients matching the inclusion criteria. Overall, our cohort had a 21% (7/33) rate of clinical and radiographic pseudomeningocele formation with 9% (3/33) requiring surgical revision or a separate procedure. The rate of clinical and radiographic pseudomeningocele formation in the myofascial cuff preservation technique was less than standard techniques (12% and 31%, respectively). Revision or further surgical procedures were also reduced in the myofascial cuff preservation technique vs. the standard technique (6% vs 13%).

Conclusions: Preservation of the myofascial cuff during posterior fossa surgery is a simple and adoptable technique that reduces the rate of pseudomeningocele formation and CSF leak as compared with standard techniques.  

Characterization and morphological comparison of human dura mater, temporalis fascia, and pericranium for the correct selection of an autograft in duraplasty procedures

PURPOSE

The objective of this study was to characterize and compare the morphological characteristics of the dura mater, the pericranium, and the temporal fascia to ascertain the most adequate tissue to use as a dura graft.

METHODS

20 dura mater, 20 pericranium and 20 temporalis fascia samples were analyzed. Each of the samples was stained with hematoxylin and eosin, orcein, Van Gieson, Masson's trichrome and Verhoeff-Van Gieson (600 slides in total) for a general morphological evaluation, as well as a quantitative, morphometric and densitometric analysis of elastic fibers present in each of the tissues.

RESULTS

The micro-densitometric analysis of the tissues indicated that the area occupied by the elastic fibers showed values of 1.766 ± 1.376, 4.580 ± 3.041, and 8.253 ± 4.467 % for the dura mater, the temporalis fascia and the pericranium, respectively (p < 0.05, all pairs). The values observed in the analysis of the density intensity were 3.42E+06 ± 2.57E+06, 1.41E+07 ± 1.28E+07, and 1.63E+07 ± 9.19E+06 for the dura mater, the temporalis fascia and the pericranium, respectively (p < 0.05), dura mater vs. temporalis fascia and dura mater vs. pericranium).

CONCLUSIONS

This is the first study to compare the dura mater with tissues for dural autograft and to quantify the elastic component present in these tissues. The results indicate that the temporalis fascia is a better dural graft because of its intrinsic tissue properties.