Dural Reconstruction Research Articles

Controversies in the Management of Open Fractures of the Skull Base

Skull base trauma is a very important trauma with big consequences in patients' health. Our group has 240 patients who underwent reconstruction surgery in the following skull base trauma locations: anterior (162), middle (70), and posterior (6). In addition, 2 patients had post-traumatic exchange volumes of orbital space. During anterior skull base reconstruction, we protected the olfactory structures in 91%. Mortality in our series was 1.7%, post-traumatic morbidity 17%, and postoperative morbidity 0.6%. Follow-up in this series was 17 years. We studied different post-traumatic pathological problems on olfactory structures, i.e., destruction or contusion or hematoma into the olfactory bulb, destruction of the olfactory tract, and destruction or contusions in the olfactory trigonum. In our series, we preferred acute operations and reconstructions of open skull base fractures with achievable goals. The method we preferred for reconstruction involved vascularized flaps for reconstruction of dura. We will discuss problems of acute and delay reconstructions, as well as mortality and morbidity. We have 17 years of experience with acute operations and reconstructions, diagnostic techniques, treatment, and follow-up of patients.

Robotic Assisted Transantral Endoscopic Surgery of the Skull Base

Background: Transnasal endoscopic approaches are being increasingly used for resection of tumors of the anterior skull base. One major limitation of this approach is the inability to provide watertight dural reconstruction.

Surgical resection without dural reconstruction of a lumbar meningioma in an elderly woman

Meningiomas of the spine occur in the thoracic spine in approximately 80%, followed in frequency by the cervical and lumbar regions. The treatment of spinal meningiomas is complete surgical resection. As intraspinal meningiomas are almost always adherent to the dura, extensive dural resection or diathermic treatment of the dural attachment is usually performed to prevent tumor recurrence. The authors present the case of lumbar spinal meningioma in 82-year-old woman. Successful resection with preservation of the dura mater using the technique of Saito et al. (Spine 26:1805-1808, 2001) is described: After lumbar laminectomy a small incision was made in the surface of the spinal dura. The dura mater was separated into its inner and outer layers, and the tumor was resected with inner layer alone, preserving the outer layer. The outer layer is simply closed to achieve a watertight seal. The pathologic diagnosis was metaplastic (osseous) meningioma. Almost full recovery of the neurologic deficit was attained. Neither complication nor tumor recurrence has occurred in the 5 years since surgery. Dural preservation during surgical resection of spinal meningioma obviates the need for dural reconstruction and should reduce surgical morbidity. However, the patient should be followed long-term to watch for recurrence.

What Are the Limits of Endoscopic Sinus Surgery?: The Expanded Endonasal Approach to the Skull Base

The advent of endoscopic technologies and techniques has expanded the limits of conventional endoscopic sinus surgery. The expanded endonasal approach describes a series of surgical modules in the sagittal and coronal planes that allow surgical access to the entire ventral skull base. The sagittal plane extends from the frontal sinus to the second cervical vertebra. The coronal plane extends from the midline to the roof of the orbit, the floor of the middle cranial fossa, and the jugular foramen. Key principles of endonasal skull base surgery are choosing a surgical corridor that minimizes the need for neural and vascular manipulation, team surgery, use of the endoscope to enhance visualization, and bimanual tumor dissection under direct visualization. Particular challenges of the expanded endonasal approach are identification of anatomical structures using unfamiliar landmarks, hemostasis, and dural reconstruction. Over the last decade with more than 1000 completely endonasal skull base surgeries, we have demonstrated that endoscopic endonasal surgery of the skull base can be performed with minimal morbidity and mortality. The introduction of the septal mucosal flap for dural reconstruction has decreased the incidence of postoperative cerebrospinal fluid leaks to less than 5%. Early data suggests that oncological outcomes for malignant sinonasal tumors with skull base involvement are comparable to conventional techniques. Proper training in endonasal surgical techniques is essential to prevent unnecessary morbidity and achieve good outcomes.

A new modified dura mater implant: characteristics in recipient dogs

Duraplasty is critical to the maintenance of anatomical integrity and the protection of brain tissue. Allotransplantation of cadaveric dura mater was abandoned after it was found to transmit Creutzfeldt-Jakob disease (CJD). In this study, the usefulness of a xenogeneic dura mater for dural reconstruction was tested. Twelve dogs were randomly assigned to 4 groups. To simulate the condition of patients with brain surface injury, an area of approximately 2 cm × 1.5 cm of the dura mater was removed to create a defect. Xenogeneinc dura mater derived from porcine pericardium was trimmed to the shape and size of the defect and sutured to the endogenous dura mater. Muscles at the apex of the skull and scalp were also sutured. Three dogs were euthanized at 3, 6, 9, and 12 months after implantation and the xenogeneic dura mater and surrounding endogenous tissue were examined macroscopically and microscopically. Three months after implantation, the graft site had begun to heal. Macroscopically, at 6, 9, and 12 months after implantation, the graft had healed completely with the surrounding tissue. No boundary between the graft and surrounding tissue was distinguishable, and the two could not be separated. The graft was smoothly epithelialized and nonadherent to the brain surface. Microscopically, the inner surface of the implant was covered with epithelial cells, and internal capillaries, subepithelial fibrous tissue deposition, and fibroblast proliferation were observed. The xenogeneic dura mater progressively degraded over time. No cysts and no neutrophilic or lymphocytic inflammatory cell response developed between the implant and the recipient brain parenchyma. The modified xenogeneic dura mater is sufficiently biocompatible to allow epithelialization of its inner surface without adherence to brain tissue. No abnormalities develop in recipients, and the xenograft is gradually biodegraded and replaced by endogenous tissue identical to the endogenous dura mater.

Efficacy and safety of a collagen matrix for cranial and spinal dural reconstruction using different fixation techniques

The use of dural grafts is frequently unavoidable when tension-free dural closure cannot be achieved following neurosurgical procedures or trauma. Biodegradable collagen matrices serve as a scaffold for the regrowth of natural tissue and require no suturing. The aim of this study was to investigate the efficacy and safety of dural repair with a collagen matrix using different fixation techniques. A total of 221 patients (98 male and 123 female; mean age 55.6 +/- 17.8 years) undergoing cranial (86.4%) or spinal (13.6%) procedures with the use of a collagen matrix dural graft were included in this retrospective study. The indications for use, fixation techniques, and associated complications were recorded. There were no complications of the dural graft in spinal use. Five (2.6%) of 191 patients undergoing cranial procedures developed infections, 3 of which (1.6%) were deep infections requiring surgical revision. There was no statistically significant relationship between the operative field status before surgery and the occurrence of a postoperative wound infection (p = 0.684). In the 191 patients undergoing a cranial procedure, cerebrospinal fluid (CSF) collection occurred in 5 patients (2.6%) and a CSF fistula in 5 (2.6%), 3 of whom (1.6%) required surgical revision. No patient who underwent an operation with preexisting CSF leakage had postoperative CSF leakage. Postoperative infection significantly increased the risk for postoperative CSF leakage. The collagen matrix was used without additional fixation in 124 patients (56.1%), with single fixation in 55 (24.9%), and with multiple fixations in 42 (19%). There were no systemic allergic reactions or local skin changes. Follow-up imaging in 112 patients (50.7%) revealed no evidence of any adverse reaction to the collagen graft. The collagen matrix is an effective and safe cranial and spinal dural substitute that can be used even in cases of an existing local infection. Postoperative deep infection increases the risk for CSF leakage.

Endoscopic endonasal suturing of dural reconstruction grafts: a novel application of the U-Clip technology

Cerebrospinal fluid (CSF) leakage following endoscopic endonasal skull base resection can be a significant problem. A method for securing tissue grafts is needed. In this paper the authors used an endonasal suturing device to secure the graft reconstruction following endonasal tumor resection. The U-Clip anastomotic device (Medtronic), developed for cardiovascular anastomoses, was used to secure the tissue graft to native dura. A specialized needle driver and hemoclip applier were used for the application and deployment of this device. No suture tying was necessary, facilitating its endonasal application. The graft was successfully secured in its desired position to native dura by using the U-Clip anastomotic device. The patient did not suffer a postoperative CSF leak, and postoperative imaging and endoscopy revealed that the graft was in a good position. There was no complication from the use of the device. The U-Clip anastomotic device can be used as a suture device during endonasal surgery. It may prevent tissue graft migration and help prevent CSF leakage.

Skull base reconstruction in the extended endoscopic transsphenoidal approach for suprasellar lesions

The extended transsphenoidal approach to the suprasellar region has the advantages of minimal invasiveness and brain manipulation in the surgical treatment of small to medium lesions. At the same time, however, it carries a higher risk of postoperative cerebrospinal fluid (CSF) leakage and related complications than those for the standard transsphenoidal approach. Effective reconstruction of large skull base defects is a major concern in such extended approaches and remains challenging. Between January 2004 and April 2006, 21 patients affected by different suprasellar lesions underwent the extended endoscopic endonasal transtuberculum-transplanum approach. Three different techniques were used for the skull base reconstructions. In all cases, dehydrated human pericardium (Tutoplast) for dural reconstruction and a copolymer of L-lactic acid and glycolic acid (LactoSorb) as a bone substitute were used. Collagen sponges, fibrin glue, and an inflated Foley balloon catheter were also used to fill the sphenoid sinus cavity. Two cases of postoperative CSF leaks (9.5%) and one case of mycotic sinusitis (4.8%) occurred following the intradural (inlay) and intraextradural (inlay-overlay) graft positioning. No cases of postoperative CSF leakage occurred in cases in which the extradural-only reconstruction procedure was applied. No meningitis or other complications related to the closure were noticed. The rate of postoperative CSF leakage after an extended approach to the suprasellar area is higher compared with that following standard pituitary surgery. Reconstruction after craniopharyngioma surgery exposes patients to an increased risk of postoperative CSF leaks. The extradural (overlay) technique was found to be the most effective in assuring a watertight closure.

Safety and efficacy of the porcine small intestinal submucosa dural substitute: results of a prospective multicenter study and literature review

Dural substitutes are often needed after neurosurgical procedures to expand or replace dura mater resected during surgery. A new dural repair material derived from porcine small intestinal submucosa (SIS) was evaluated in a prospective multicenter clinical study. Between 2000 and 2003, 59 patients at five different institutions underwent dural reconstruction with the SIS dural substitute, with a minimum follow up of 6 months. The primary goals of the study were to assess the efficacy and safety of the SIS dural substitute according to the rate of cerebrospinal fluid (CSF) leakage, infection, and meningitis. Chiari malformation Type I decompression (32 patients) and tumor resection (18 patients) were the most common procedures performed, with 81% of SIS grafts implanted in the posterior fossa or spine. There was one case of a CSF leak (1.7%), two cases of wound infection (3.4%), and no cases of bacterial meningitis (0%) in the 58 patients available for follow up. In both cases of wound infection, the SIS graft acted as a barrier to infection and was not removed. Intraoperatively, a watertight seal was achieved in all 59 cases. On follow-up imaging available in 27 patients there was no evidence of any adverse reaction to the graft or of cerebral inflammation. The SIS dural substitute demonstrated substantial efficacy in these patients after a mean follow up of 7.3 +/- 2.2 months. Rates of infection, CSF leakage, and meningitis were comparable to those reported for other dural substitute materials. A lack of adverse reactions to the graft, favorable safety profile, and clinical efficacy all point to the utility of this material as an alternative for dural repair.

The Skull Base Trauma: Management and Treatment

Our group had 214 patients: the anterior skull base 146, middle 64, posterior 2, and 2 patients with post-traumatic exchange volume of orbital space and their reconstruction. During anterior skull base reconstruction, we protected the olfactory structures in 91%. Mortality rate in our series was 1.7%, post-traumatic morbidity 17%, and postoperative morbidity 0.6%. Follow-up in this series was 14 years. We studied different pathological post-traumatic problems in olfactory structures-destruction or contusion or hematoma of the olfactory bulb, destruction of the olfactory tract, and destruction or contusions in the olfactory trigonum. In our series we preferred acute operations and reconstructions of open skull base fracture with very effective goals. In the reconstruction method we preferred vascularized flaps for reconstruction of dura. The authors discuss problems of acute and delayed reconstruction, and mortality and morbidity. The authors have 14 years' experience with acute operations and reconstructions, diagnostic techniques, treatment, and follow-up of patients.

Prevention and Treatment of CSF Leakage at Skull Base Surgery

Introduction: CSF leak is a dangerous complication of skull base surgery. The aim of our study is prevention of CSF leakage for skull base surgery. Methods: The experimental part of the research was carried out on 50 rabbits. Fat and fascial grafts were compared for dural reconstruction. On the 3d, 7th, and 14th days postoperatively, the strength and watertightness of the dural repair were tested, then a histomorphological study was conducted. The clinical part of the research included 219 patients with anterocentral (54 patients) and posterolateral (165 patients) postoperative defects of skull base. We found main factors which assist in causing postoperative CSF leaks and designed a numerical scale for evaluation of the degree of risk. Results: Fat grafts provide the most watertight dural closure. Fat tissue is vascularized from the surrounding tissues in 7 days. We designed an algorithm of differentiated use of prevention methods depending on the degree of risk for CSF leakage: use of fat only in the case of minimal risk; use of fat with fibrin glue for moderate risk; a combination of these two actions with lumbar drainage for maximal risk. As a result, for the first group we noticed only 3 patients (5.4%) with CSF leakage. In the second group we lowered the number of patients with postoperative CSF leakage from 9.8% to 2.1% (p < 0.05). Conclusion: The use of the numeric scale of risk degree evaluation allows the determination of a CSF leak arising and the choice of the optimal algorithm for skull base reconstruction. The use of fat graft for watertight dural closure is more effective than the fascial graft.

Surgical resection of lumbar spinal meningioma without dural reconstruction: a case report

Surgical resection of lumbar spinal meningioma without dural reconstruction: a case report

CO2 Laser Fascia to Dura Soldering for Pig Dural Defect Reconstruction

The purposes of this study were to demonstrate that laser soldering is safe and effective for tissue bonding in dural reconstruction and to compare this new reconstruction technique to an established one. A temperature-controlled fiberoptic CO(2) laser system or fibrin glue were used for in vitro dural defect reconstruction in two groups of pigs. The CO(2) laser technique was also used for dural reconstruction in live pigs. The burst pressure of the reconstructed dura by the laser system was significantly higher than that of fibrin glue (mean pressure 258.5 +/- 117.3 cm H(2)O and 76.8 +/- 47.2 cm H(2)O, respectively). There were no postoperative complications and no signs of thermal damage to the dura, fascia, or underlying tissue on histological analysis following the in vivo CO(2) laser experiments. Temperature-controlled laser soldering is an effective technique for dural repair. It creates a strong tissue bonding with no thermal damage to the tissue. The burst pressure of the reconstructed dura done with laser soldering is significantly higher than that of fibrin glue.

Robotic-Assisted Endoscopic Resection and Repair of the Anterior Skull Base

Background: Transnasal endoscopic approaches are being increasingly utilized for resection of tumors of the anterior skull base. One major limitation of this approach is the inability to provide watertight dural reconstruction.

Durectomy and reconstruction for the treatment of a recurrent spinal meningioma

The management of spinal meningiomas with extensive involvement of the dura mater is controversial. The principal difficulty in performing a resection is the potential for complications associated with this approach. The authors present the case of a pregnant 35-year-old woman in whom bilateral lower-extremity numbness, weakness, gait ataxia, and myelopathy developed. Magnetic resonance imaging showed a recurrent thoracic meningioma with extensive infiltration of the dura mater. Durectomy, complete resection, and reconstruction were performed. The patient has not experienced a recurrence 21 months after her treatment. This case illustrates that thoracic spinal meningiomas with extensive dural involvement can be resected safely with a complete durectomy. The novel dural reconstruction involving the implantation of a fascia lata and bovine pericardium allograft is an effective way to reconstruct the dura to create an adequate barrier to cerebrospinal fluid.

Dural Defect Repair with Fascia by a CO2 Laser System in a Porcine Model

We tested the effectiveness of a temperature-controlled CO2 laser soldering system on a porcine model for dural defect reconstruction using a fascial patch. A dural patch was excised and then reconstructed with fascia by a CO2 laser system in vitro in 27 animals and in vivo in five animals. After dural reconstruction, the average burst pressure of the soldered patch in vitro, as measured by a custom-made pressure detector, was 258.5 cm H2O. All five pigs in the in vivo group showed no neurological complications or cerebrospinal fluid leak, and the underlying brain tissue showed no thermal injury. The CO2 laser system created a watertight bond and did not cause thermal injury to the brain. The procedure is potentially faster than conventional repair, and wound healing may also be more rapid.

Autologous tissues for dural grafting in children: a report of 56 cases

Diverse materials have been used for dural closure, including grafts of cadaveric origin. Some 168 cases of Creutzfeldt-Jakob disease have been reported following the implant of human dura mater. A few publications have addressed the use of dural grafts in children, but none has analyzed the feasibility of autologous tissues for this purpose. Since 1994, the authors have utilized autologous tissues for dural grafting in children undergoing neurosurgical procedures, aimed at studying the feasibility of its use in this age group. We studied 56 children submitted to neurosurgical procedures who underwent an implant of a patch of autologous tissue for dural closure. Epidemiological, clinical, and neuroimaging data were processed using statistical methods. The study group was composed of 29 boys and 27 girls, with ages ranging from 1 month to 17 years (mean 7.6 years). The procedures corresponded to lesions at the posterior cranial fossa (n = 41), supratentorial cranial compartment (n = 12), and spine (n = 3). Seventy-five percent of the children had no complication. Four patients had adverse effects unrelated to dural grafting, while ten children had complications that might be associated with it. The most frequent complication was pseudomeningocele (n = 6), followed by infection (n = 3) and CSF leak (n = 1). Although hydrocephalus seemed to have an influence on the occurrence of complications, their incidence in patients without hydrocephalus did not differ statistically. Autologous grafts of fascia or pericranium can be safely used for dural reconstruction in children. Given the reported complications associated with the use of foreign materials for duraplasty, the authors recommend the use of autologous tissues for dural repair, reserving other types of dural grafts for cases in which its usage is unavoidable.

Novel laser tissue-soldering technique for dural reconstruction

The goal of this study was to use a modified version of the CO2 laser-soldering system to develop a simple and reliable technique for the repair of dural defects after excision of brain tumors. The authors used a CO2 fiber optic laser system that they had developed for heating, monitoring, and controlling tissue temperature in situ and in real time, thereby reducing damage to the brain parenchyma. They adapted the system for dural closure by using free fascial grafts in a porcine model. Measures for estimation of reconstruction quality included visual assessment under magnification and direct measurements of adhesive strength and cerebrospinal fluid leak (CSF) pressure. Reliable soldering was achieved in 54 of 57 experiments, providing a 95% success rate. The average peak adhesive strength was 82 +/- 3 mN/cm2. The measured leak pressure of the fascia-dura mater bond was 66 +/- 5 mm Hg. Conventional suturing performed using Prolene stitches resulted in immediate CSF leakage from areas between the stitches and from the area of the needle hole itself. Fascia-dura mater soldering using the CO2 laser is feasible and may support CSF pressure up to six times higher than normal intracranial pressure. Findings of this study may provide a basis for the development of new tools for dural reconstruction.

A new collagen biomatrix of equine origin versus a cadaveric dura graft for the repair of dural defects – a comparative animal experimental study

Numerous types of materials have been evaluated over the past decades in the quest for the ideal dural replacement, but no product fully meets all the applicable criteria. This paper presents the long-term results of an animal trial of a collagen biomatrix (TISSUDURA, Baxter AG, Vienna/Austria) for the repair and regeneration of dural defects. This product provides a matrix with a special layer structure and consists of pure naturally cross-linked collagen of equine origin. The comparable material is Tutoplast Dura, a human cadaveric-derived dural graft preserved in a multiple stage chemical process. Bihemispheric parietotoccipital dural defects of a defined size were induced in 25 sheep and subsequently closed with the collagen graft or Tutoplast Dura, respectively. Postoperative neurological abnormalities did not occur in any animal. There were no signs of graft rejection or formation of cerebrospinal fluid fistulae. The collagen graft site displayed histological signs as early as 2 weeks postoperatively consistent with a moderate Iymphocytic inflammatory response and infiltration with fibroblasts and macrophages. The graft subsequently developed a neodura-like connective tissue architecture. The Tutoplast Dura showed only minimal cellular infiltration, and again the surrounding structures displayed a mild inflammatory response. 24 weeks postoperatively, the dura and neomembrane were barely distinguishable at the collagen biomatrix site, but the Tutoplast Dura displayed inadequate fusion with the dural border and was encapsulated in a connective tissue layer. The outcomes demonstrate that the collagen graft can be used for dura reconstruction as a temporary dural replacement and at the same time as a biomatrix for dural regeneration.

Development of a novel technique for laser reconstruction of the dura

Objectives: Laser tissue welding is a technology that was used for soldering of various tissues, which can be faster, less traumatic and easier to apply than conventional methods. The objective of this study was to take advantage of the laser soldering system, and to develop a simple and reliable technique for repair of dural holes after excision of brain tumors. Methods: We used a CO 2 fiber optic laser system that was developed by us for monitoring and controlling heated tissue in situ and in real time, for reducing the damage to the brain parenchyma. The system was used for soldering of dura and free fascial grafts in an animal model using pigs. Direct digital measurements of mechanical force interaction were used for tension and pressure. Results: The difference between the breaking point of the retract scan and the baseline was used to calculate the peak adhesive force (PAF) acting between the 2 tissues. We have performed 35 experiments in order to calculate the mean PAF of fascia-dura welding. Seven more experiment were performed using biological glue for comparison of the PAF. The mean PAF of fascia-dura welding was 3.94 ± 0.6 gr/cm. The PAF for fascia-dura bond using biological glue was 4.1 ± 1.2 gr/cm. No statistical difference was found between the 2 techniques. Conclusion: Implementation of laser welding in neurological oncological surgeries will allow access to anatomical areas previously considered inoperable, will shorten the length of the surgery, will allow better dural reconstruction shortly after the procedure, and therefore allow lower morbidity and mortality rates.