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

The environmental impact of extracellular matrix preparation

The extracellular matrix (ECM) is a network of proteins and other molecules that encase and support cells and tissues in the body. As clinical and biotechnological uses of ECM are expanding, it is essential to assess the environmental impact associated with its production. Due to high levels of customization, various laboratories employ distinct methods; therefore, this study evaluates three common protocols. Life cycle assessment (LCA) methodology has been developed to evaluate the environmental impacts of products produced through diverse processes. Despite its widespread application in the pharmaceutical industry, LCA has seldom been utilized to estimate the environmental effects of laboratory protocols. This Viewpoint applies LCA to assess the functionality and environmental impacts of ECM produced via P1, P2, and P3. The results of this assessment indicate that the protocol with the highest impact generates approximately 43 times more CO2-equivalent emissions (CO2 eq) than that with the lowest impact, while the ECM produced using the least impactful protocol demonstrates the highest biocompatibility. Additional environmental indicators such as eutrophication, photochemical oxidation, and acidification also vary among the tested protocols. This work underscores the need to factor environmental impact in the development of novel biomedical materials.

PEG hydrogel sealant versus fibrin glue in posterior fossa surgery: an economic comparison across five European countries

Aim: Posterior cranial fossa (PCF) surgery is associated with complications, including cerebrospinal fluid (CSF) leakage. Dural sealants such as polyethylene glycol (PEG)-based hydrogels and fibrin glue can prevent CSF leaks, with evidence suggesting PEG hydrogels may outperform fibrin glue. However, the budget impact of using PEG hydrogels in PCF surgeries in Europe is unclear. Materials & methods: A decision tree was developed based on a previous US model, to assess the budget impact of switching from fibrin glue to PEG hydrogel in PCF surgery across five European countries. Input costs were derived from published sources for the financial year 2022/2023. Health outcomes, including CSF leaks, were considered. Results: The model predicted that using PEG hydrogel instead of fibrin glue in PCF surgery can lead to cost savings in five European countries. Cost savings per patient ranged from EUR 419 to EUR 1279, depending on the country. Sensitivity analysis showed that the incidence of CSF leaks and pseudomeningoceles had a substantial impact on the model's results. Conclusion: PEG hydrogels may be a cost-effective alternative to fibrin glue in PCF surgery. The model predicted that cost savings would be mainly driven by a reduction in the incidence of postoperative CSF leaks, resulting in reduced reliance on lumbar drains, reparative surgery and shortened hospital stays.

Biosubstitutes for dural closure: Unveiling research, application, and future prospects of dura mater alternatives

The dura mater, as the crucial outermost protective layer of the meninges, plays a vital role in safeguarding the underlying brain tissue. Neurosurgeons face significant challenges in dealing with trauma or large defects in the dura mater, as they must address the potential complications, such as wound infections, pseudomeningocele formation, cerebrospinal fluid leakage, and cerebral herniation. Therefore, the development of dural substitutes for repairing or reconstructing the damaged dura mater holds clinical significance. In this review we highlight the progress in the development of dural substitutes, encompassing autologous, allogeneic, and xenogeneic replacements, as well as the polymeric-based dural substitutes fabricated through various scaffolding techniques. In particular, we explore the development of composite materials that exhibit improved physical and biological properties for advanced dural substitutes. Furthermore, we address the challenges and prospects associated with developing clinically relevant alternatives to the dura mater.

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.

Evaluation of Adult and Pediatric Chiari Type 1 Malformation Patients: Do Consensus Documents Fit Everyday Practice?

The management of Chiari 1 malformation (CM1) and Syringomyelia (Syr) has shown many changes in surgical indications and techniques over time. The dedicated neurosurgical and neurological community recently planned to analyze the state of the art and find conduct uniformity. This led to international consensus documents on diagnostic criteria and therapeutic strategies. We aimed to evaluate, in a large, monocentric surgical series of adult and children CM1 patients, if the daily clinical practice reflects the consensus documents. Our series comprises 190 pediatric and 220 adult Chiari patients submitted to surgery from 2000 to 2021. The main indications for the treatment were the presence of Syr and symptoms related to CM1. While there is great correspondence with the statements derived from the consensus documents about what to do for Syr and symptomatic CM1, the accordance is less evident in CM1 associated with craniosynostosis or hydrocephalus, especially when considering the early part of the series. However, we think that performing such studies could increase the homogeneity of surgical series, find a common way to evaluate long-term outcomes, and reinforce the comparability of different strategies adopted in different referral centers.

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.

Outcome evaluation of decompression surgery combined with cerebellar tonsillectomy compared without cerebellar tonsillectomy for Chiari type I malformation patients

BACKGROUND

Surgical intervention is an important treatment option to improve the prognosis for Chiari type I malformation (CM-I) patients. However, there is no consensus about surgical strategies. The article intends to evaluate the effect of decompression combined with or without cerebellar tonsillectomy in the treatment of CM-I.

METHOD

Following PRISMA's principles, Embase, PubMed, Web of Science, and Cochrane databases and references to relevant articles were searched to include only original articles on decompression combined with or without cerebellar tonsillectomy in CM-I patients. Through meta-analysis, the data on clinical improvement, radiological improvement, and complications were pooled.

RESULTS

Nine articles, including 399 CM-I patients undergoing decompression alone and 343 undergoing decompression with cerebellar tonsillectomy, meet the inclusion standard. In comparison, the improvement rate of clinical symptoms or signs in patients with cerebellar tonsillectomy is higher and statistically significant (RR: 0.85, 95% CI: 0.75-0.95; P = 0.006). However, decompression with cerebellar tonsillectomy is also significantly higher in the incidence of postoperative complications (RR: 0.54, 95% CI: 0.36-0.80; P = 0.002). No statistical difference is discovered between the two groups in the improvement rate of syringomyelia (RR: 0.77, 95% CI: 0.57-1.03; P = 0.08).

CONCLUSIONS

Although decompression with cerebellar tonsillectomy is superior than decompression alone in clinical improvement for CM-I patients, it also faces a higher risk of postoperative complications. The reduction of syringomyelia in the two groups can be considered equally effective without significant differences. In the future, the results of the research require multicenter and large-scale randomized controlled trials to verify in clinical practice.

TRIAL REGISTRATION

CRD42022321750 (PROSPERO).