Review of dura mater substitutes in neurosurgical practice

AIM: This study aimed to summarize the accumulated experience and compare available materials for the plasty of dura mater (DM) defects. The growing number of patients with craniocerebral traumas and an increasing amount of neurological surgeries for tumor processes and congenital malformations resulted in an increased amount of DM defects and associated complications. Despite the development of high-efficiency medical products, the percentage of postsurgical CSF leakage remains high and reaches 32% in case the defect is in infratentorial locations. Suitable substitute materials should be developed for the repair of dural defects because of complications such as pseudomeningocele, postsurgical inflammatory processes, CSF leakage, implant rejection, and cicatrical adhesion. In this article, basic materials, including auto- and allografts, biological substances, and synthetic materials, for the repair of dural defects were reviewed. Their positive and negative properties depending on the kind and location of lesions and on the type of material used were discussed. The main characteristics to be fulfilled by an ideal dura mater substitute were analyzed. Composite materials were considered a promising trend in modern bioengineering. CONCLUSION: An ideal material for the repair of DM defects should have the following properties: plastic, nonimmunogenic, watertight, highly porous, high surface area of fibers, cell growth stimulating, supportive for the survival of cells until they completely integrate with host tissues, conveniently replaceable, and adhesive. No ideal transplant materials can meet all the above demands. Biological, synthetic, and host tissues only supplement one another. Relevant studies have yet to be performed to obtain a more versatile and time and cost effective material that can satisfy all the requirements of modern neurosurgery. The existing results of preclinical studies have demonstrated that composite materials are similar to synthetic materials in terms of the strength and properties of biological tissues for the migration and proliferation of cells. In the future, they may become a promising alternative to biological substitutes.

Risk Factors and Reconstruction Techniques for Persistent Cerebrospinal Fluid Leak in Patients Undergoing Endoscopic Endonasal Approach to the Posterior Fossa

Background High-flow skull base dural defects are associated with an increased risk of postoperative cerebrospinal fluid (CSF) leaks. Objective This study aimed to identify the risk factors for persistent postoperative CSF leak after endoscopic endonasal surgery (EES) and determine the ideal reconstruction strategy after initial failed repair. Methods Patients with CSF leak after intradural EES between October 2000 and February 2017 were identified. Cases with persistent CSF leak were compared with patients with similar pathologic diagnosis without a persistent leak to identify additional risk factors. Results Two hundred and twenty-three out of 3,232 patients developed postoperative CSF leak. Persistent leaks requiring more than one postoperative repair occurred in 7/223 patients (3.1%). All seven had undergone intradural approach to the posterior fossa for resection of recurrent/residual clival chordomas. This group was matched with 25 patients with recurrent/residual clival chordoma who underwent EES without postoperative CSF leak (control group). Age, gender, history of diabetes, smoking, or radiotherapy were not statistically different between the groups. Obesity (body mass index > 30) was significantly more common in the group with persistent leak (86%) compared with controls (36%) (p = 0.02). All patients with a persistent CSF leak developed meningitis (p = 0.001). Five patients with persistent leak required a pericranial flap to achieve definitive repair. Conclusion Multiple recurrent CSF leak after EES primarily occurs following resection of recurrent/residual posterior fossa chordoma. Obesity is a major risk factor and meningitis is universal with persistent leak. Flap necrosis may play a role in the development of persistent CSF leaks, and the use of secondary vascularized flaps, specifically extracranial–pericranial flaps, should be considered as an early rescue option in obese patients.

Intradural extraarachnoid sutureless technique combined with laminoplasty for indirect repair of ventral dural defects in spontaneous intracranial hypotension: technical note and case series

Background There is a significant variance in surgical treatment strategies of ventral cerebrospinal fluid (CSF) leaks causing spontaneous intracranial hypotension (SIH). Posterior approaches might represent a preferable alternative to the more invasive anterior and lateral routes, as long as the spinal cord is not exposed to harmful manipulation. The aim of this technical note is to report and illustrate a new surgical technique using an intradural extraarachnoid sutureless technique via laminoplasty for indirect repair of ventral CSF leaks causing intractable SIH symptoms. Methods The surgical technique is described in a step by step fashion. Between May 2018 and May 2020, five patients with ventral spinal CSF leaks were operated on, utilizing this technique. All dural defects were located at the level of the thoracic spine. A retrospective review on demographic and radiological findings, symptoms, outcome, and follow-up was performed. Results The intra- and postoperative course was uneventful in all patients with no surgery-related complications. Three patients recovered completely at discharge, while neurological symptoms significantly improved in two patients. A postoperative MRI of the spine was obtained for all patients, demonstrating regressive signs of CSF leak. Conclusion Based on the presented case series, this intradural extraarachnoid sutureless technique combined with laminoplasty seems to be a safe and effective option for indirect repair of ventral dural defects in SIH. In our opinion, it represents a valid alternative to traditional more aggressive approaches.

A Diskogenic Dural Defect is the Reason for the Ventral Location of the Epidural Spinal Fluid Collection Seen in Superficial Siderosis

Purpose of reviewSuperficial siderosis (SS) of the nervous system is often due to a dural pathology. This review focuses on recent developments related to the management of this subgroup of SS patients.Recent findingsThe presence of an epidural ventral spinal fluid collection in patients with SS is a clue to the presence of a diskogenic dural defect. The location of the defect is ascertained by a dynamic CT-myelogram which involves placing the patient in a prone position with hips elevated. This permits gravity assisted preferential ventral localization of the contrast and active scanning during contrast injection facilitates a precise delineation of the initial point of contrast extravasation which localizes the defect.SummaryDiskogenic dural defects are commonly the underlying etiology for SS in patients with a ventral spinal fluid collection. A dynamic CT-myelogram facilitates detection and subsequent repair of these defects which arrests the continued low-grade subarachnoid bleeding.

Reconstructive Outcomes of Multilayered Closure of Large Skull Base Dural Defects Following Open Anterior Craniofacial Resection

Background Standardized reconstruction protocols for large open anterior skull base defects with dural resection are not well described. Here we report the outcomes and technique of a multilayered reconstructive algorithm utilizing local tissue, dural graft matrix, and microvascular free tissue transfer (MVFTT) for reconstruction of these deformities. Design This study is a retrospective review. Results Eleven patients (82% males) met inclusion criteria, with five (45%) having concurrent orbital exenteration and eight (73%) requiring maxillectomy. All patients required dural resection with or without intracranial tumor resection, with the average dural defect being 36.0 ± 25.9 cm2. Dural graft matrices and pericranial flaps were used for primary reconstruction of the dural defects, which were then reinforced with free fascia or muscle overlay by means of MVFTT. Eight (73%) patients underwent anterolateral thigh MVFTT, with the radial forearm, fibula, and vastus lateralis comprising the remainder. Average total surgical time of tumor resection and reconstruction was 14.9 ± 3.8 hours, with median length of hospitalization being 10 days (IQR: 9.5, 14). Continuous cerebrospinal fluid drainage through a lumber drain was utilized in 10 (91%) patients perioperatively, with an average length of indwelling drain of 5 days. Postoperative complications occurred in two (18%) patients who developed asymptomatic pneumocephalus that resolved with high-flow oxygen therapy. Conclusion A standardized multilayered closure technique of dural graft matrix, pericranial flap, and MVFTT overlay in the reconstruction of large open anterior craniofacial dural defects can assist the reconstructive team in approaching these complex deformities and may help prevent postoperative complications.

Biomimetic Hierarchical Small Intestinal Submucosa-Chitosan Sponge/Chitosan Hydrogel Scaffold with Micro/Nano Structure for Dural Repair

The dura mater is an essential barrier to protect the brain tissue and the dural defects caused by accidents can lead to serious complications. Various materials have been applied to...