Synthetic Dural Graft Research Articles

Comparative Analysis of Duroplasty Techniques in Decompressive Craniectomy: The CANDID Study.

At present, there is no consensus regarding the most optimal dural substitute to use for duroplasty in primary decompressive craniectomy (PDC) for traumatic brain injury (TBI). The author's objective was to conduct a retrospective analysis comparing 2 techniques of PDC: duroplasty using anterior-based vascularized galea pericranium (VP group) with synthetic dural substitute duroplasty (SR group). From April 2015 to February 2022, 379 craniotomies were done for TBI. The outcome of eligible 97 consecutive patients receiving PDC treatment were examined. Out of 97, 60 received vascularized galea pericranium and 37 received synthetic dural graft for dural augmentation. Propensity matching generated 28 pairs (56 patients) for analysis. The primary outcome was extended Glasgow Outcome Scale (GOS-E) measured at 6 months after injury. Secondary outcomes included were incidence of surgical complications (neurosurgical site infections, and hemorrhagic and hydrodynamic complications), surgical time, days in intensive care unit, hospital length of stay, hospital mortality, and GOS-E at 1 year after injury. Patients in VP group, compared with those in SR group had better GOS-E score at 6 months (P = .011) and 1 year (P = .026). Hospital mortality (P = .342), days in intensive care unit (P = .574), hospital stay (P = .155), surgical time (P = .131), medical and surgical complications including neurosurgical infections, and hemorrhagic and hydrodynamic complications did not differ significantly in both groups. Complication of brain abscess was found exclusively in the SR group (P = .327). In this retrospective study, adults who underwent PDC for TBI using anterior-based vascularized galea pericranial graft were associated with better clinical outcomes at 6 months and 1 year compared with standard repair group using synthetic dural substitute (G patch).

An autologous duraplasty in situ technique in the treatment of Chiari malformation Type I: a prospective study.

Our study aims to prospectively compare an autologous duraplasty in situ technique (IS group) with the synthetic dural graft duraplasty (SDG group) to clarify the effectiveness and superiority of the former in the treatment of patients with Chiari malformation type 1 (CM-I). 29 patients with CM-I were randomly assigned to either IS or SDG group. In both groups, a dissection from the occipital bone was performed. All procedures were performed by the same surgeon. The two duraplasty methods were compared in terms of surgical factors and complications. Data analysis was done for the baseline material, the neurological outcome and MRI-documented syrinx size at the 6month follow-up. 29 patients were enrolled in this study, 14 in the IS group and 15 in the SDG group. The results showed no significant difference in operation time (P = 0.916), amount of bleeding (P = 0.120), operation complications, hospitalization time (P = 0.854) and prognosis between the two groups. The hospitalization cost of IS group was 15,125 yuan less than that of SDG group (P < 0.05). The autogenous duraplasty in situ technique is a novel, simple, effective and economical surgical management for patients with CM-I.

Neural tissue tolerance to synthetic dural mater graft implantation in a rabbit durotomy model.

In neurosurgical interventions, effective closure of the dura mater is essential to prevent cerebrospinal fluid leakage and minimize post-operative complications. Biodegradable synthetic materials have the potential to be used as dura mater grafts owing to their regenerative properties and low immunogenicity. This study evaluated the safety of ArtiFascia, a synthetic dura mater graft composed of poly(l-lactic-co-caprolactone acid) and poly(d-lactic-co-caprolactone acid), in a rabbit durotomy model. Previously, ArtiFascia demonstrated positive local tolerance and biodegradability in a 12-month preclinical trial. Here, specialized stains were used to evaluate potential brain damage associated with ArtiFascia use. Histochemical and immunohistochemical assessments included Luxol Fast Blue, cresyl Violet, Masson's Trichrome, neuronal nuclei,, Glial Fibrillary Acidic Protein, and ionized calcium-binding adaptor molecule 1 stains. The stained slides were graded based on the brain-specific reactions. The results showed no damage to the underlying brain tissue for either the ArtiFascia or control implants. Neither inflammation nor neuronal loss was evident, corroborating the safety of the ArtiFascia. This approach, combined with previous histopathological analyses, strengthens the safety profile of ArtiFascia and sets a benchmark for biodegradable material assessment in dura graft applications. This study aligns with the Food and Drug Administration guidelines and offers a comprehensive evaluation of the potential neural tissue effects of synthetic dura mater grafts.

Using of the Synthetic Dural Graft as Described in Bogota Bag Technique to Decrease the Adhesions in Decompressive Craniectomy.

To create an alternative synthetic dural graft using a parenteral solution bag made of polyvinyl chloride/polypropylene (PVC/ PP). Twenty-two albino rats were divided into the Sham, DC and BAG groups. Except for the Sham group animals, the right parietal bone of the rats was totally drilled in a diameter of 1.0 x 0.5 mm. Then, the PVC/PP BAG was layered over the craniectomized bone of the BAG group animals. Thirty days later, all animals were sacrificed, and inflammatory processes consisting of polymorphonuclear cell infiltration, inflammation, edema, hyperemia, lymphocytosis, histiocytosis, vascular proliferation, and fibrosis were graded at the craniectomy site. The grade values of inflammation, edema, histiocytosis, and fibrosis were found different among the groups (p < 0.017). It was observed that placing a synthetic graft to the surgical site undergoing craniectomy could prevent fibrotic adhesions that might occur between the brain tissue and scalp in the chronic period. Furthermore, it was considered that this synthetic material did not increase inflammatory processes secondary to surgery at the surgical site and did not produce a foreign body reaction, toxicity, or infection. As a result of this study, it was argued that the synthetic material used in this study could be compatible with dermal and neural tissues and reduce adhesions at the craniectomy field. Therefore, it was considered that this material could be used as an alternative synthetic dural graft in decompressive craniectomy in human subjects after detailed toxicity studies.

Circumferential dural reconstruction after excision of recurrent intradural extra medullary spinal meningioma

Abstract Background Meningiomas are the most common benign spinal tumor. Surgery is mostly curative, however, ~10% of benign spinal tumors recur. Meningioma recurrence is associated with dural invasion, degree of resection, and histological characteristics of the tumor. Resection of large ventral spinal tumors remains challenging due to a greater risk of spinal cord injury and difficult proper tumor exposure. Surgical resection techniques include en bloc resection of the tumor and involved dura, or tumor resection with extensive coagulation of the dural bed. This is the first report of successful circumferential spinal dural repair using a synthetic dural graft following resection of a recurrent WHO Grade I thoracic spinal meningioma in a pediatric patient. Case description We report our technique for 360° duraplasty of the thoracic spine following meningioma excision in a pediatric patient. The patient is a neurologically intact 17-year-old female presenting with intradural extra medullary (IDEM) WHO Grade I recurrent ventral thoracic spinal meningioma at the T10–T11 level with intraoperative evidence of nerve root invasion for which complete resection was performed. The resultant 5 cm circumferential dural defect necessitated 360° spinal thoracic duraplasty. No postoperative cerebrospinal fluid leak (CSF) or other complications related to the repair were encountered and the patient returned to baseline neurological status postoperatively. Conclusions Further follow-up will provide long-term results of this procedure and further research on the application of this technique in dural repair during different surgeries at all spinal levels is warranted.

Middle cranial fossa approach to repair tegmen defects assisted by three-dimensionally printed temporal bone models.

To explore the perioperative utility of three-dimensionally (3D)-printed temporal bone models of patients undergoing repair of lateral skull base defects and spontaneous cerebrospinal fluid leaks with the middle cranial fossa approach. Case series. 3D-printed temporal bone models-based on patient-specific, high-resolution computed tomographic imaging-were constructed using inexpensive polymer materials. Preoperatively, the models demonstrated the extent of temporal lobe retraction necessary to visualize the proposed defects in the lateral skull base. Also preoperatively, Silastic sheeting was arranged across the modeled tegmen, marked, and cut to cover all of the proposed defect sites. The Silastic sheeting was then sterilized and subsequently served as a precise intraoperative template for a synthetic dural replacement graft. Of note, these grafts were customized without needing to retract the temporal lobe. Five patients underwent the middle cranial fossa approach assisted by 3D-printed temporal bone models to repair tegmen defects and spontaneous cerebrospinal fluid leaks. No complications were encountered. The prefabricated dural repair grafts were easily placed and fit precisely onto the middle fossa floor without any additional modifications. All defects were covered as predicted by the 3D temporal bone models. At their postoperative visits, all five patients maintained resolution of their spontaneous cerebrospinal fluid leaks. Inexpensive 3D-printed temporal bone models of tegmen defects can serve as beneficial adjuncts during lateral skull base repair. The models provide a panoramic preoperative view of all tegmen defects and allow for custom templating of dural grafts without temporal lobe retraction. 4 Laryngoscope, 127:2347-2351, 2017.

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.

Skull Base Reconstruction with Titanium Mesh for Benign Complex Anterior Skull Base Tumors: Case Series and Review of the Literature

Aim: The aim of the study was to evaluate the role of titanium mesh used in combination with other synthetic materials in providing a rigid support for reconstruction of anterior skull base defect and preventing CSF leak. Material and methods: All Cases of complex benign anterior skull base lesions operated between December 2008 and December 2013 (5 years) which had titanium mesh for reconstruction were reviewed. Six operations were performed on five patients for large anterior skull base meningioma (3 cases) and fibrous dysplasia (2 cases). The main complaint was exophthalamous in 4 patients, and one presented with nasal blockage due to ethmoidal and nasal invasion. The reconstructions were performed by using titanium mesh with pericranial flaps, synthetic dural grafts, and surgical glue. Routine lumbar drain was not used. Three patients had previous surgeries. Three patients were female, and the age range was 4 to 55. We had a minimum of 12 months follow up. The incidence of CSF leak, infections, and other surgical morbidity related to the reconstruction were recorded. The status of exophthalamous post operatively was also observed. Results: We had no incidence of CSF leak or infection. One case of recurrent psuedomeningocele was encountered and it required repeated aspiration, then lumbar drain, and finally insertion of subgalial-peritoneal shunt. Exophthalamous improved in 3 patients and remain the same in one. Conclusion: Use of titanium mesh with local flaps or synthetic dural graft and surgical glue is safe, simple, and effective for reconstruction of anterior skull base defects caused by benign tumor or fibrous dysplasia.

The incidence of complications in elective cranial neurosurgery associated with dural closure material

Dural closure with synthetic grafts has been suggested to contribute to the incidence of infection and CSF leak. The objective of this study was to assess the contribution of choice of dural closure material, as well as other factors, to the incidence of infection and CSF leak. A retrospective, consecutive cohort study of adult patients undergoing elective craniotomy was established between April 2010 and March 2011 at a single center. Exclusion criteria consisted of trauma, bur hole placement alone, and temporary CSF fluid diversion. Three hundred ninety-nine patients were included (mean follow-up 396.6 days). Nonautologous (synthetic) dural substitute was more likely to be used (n = 106) in cases of reoperation (p = 0.001). Seventeen patients developed a surgical site infection and 12 patients developed a CSF leak. Multivariate logistic regression modeling identified estimated blood loss (OR 1.002, 95% CI 1.001-1.003; p < 0.001) and cigarette smoking (OR 2.198, 95% CI 1.109-4.238; p = 0.019) as significant predictors of infection. Synthetic dural graft was not a predictor of infection in multivariate analysis. Infratentorial surgery (OR 4.348, 95% CI 1.234-16.722; p = 0.024) and more than 8 days of postoperative corticosteroid treatment (OR 3.886, 95% CI 1.052-16.607; p = 0.048) were significant predictors for the development of CSF leak. Synthetic dural graft was associated with a lower likelihood of CSF leak (OR 0.072, 95% CI 0.003-0.552; p = 0.036). The use of synthetic dural closure material is not associated with surgical site infection and is associated with a reduced incidence of CSF leak. Modifiable risk factors exist for craniotomy complications that warrant vigilance and further study.

Synthetic dural graft septoplasty in epistaxis from hereditary hemorrhagic telangiectasia

It is an autosomal dominant vascular disorder, which has a variety of clinical manifestations, with epistaxis being one of the most common. Many treatment options exist for epistaxis, but with no consensus on which is the method of choice. We describe the case of a patient with hereditary hemorrhagic telangiectasia (HHT) secondary epistaxis with septoplasty managed with synthetic hard graft, which improved intensity and frequency of bleeding episodes. This technique is a variant of the septodermoplasty described by several authors, but the use of synthetic dura can help in obtaining better results and avoid taking skin grafts from other sites different from the surgical site.

Surgical site infection associated with the use of bovine serum albumine-glutaraldehyde surgical adhesive (BioGlue®) in cranial surgery: a case–control study

To enhance the water tightness of dura mater closure in cranial surgery, an organic glue called BioGlue was used in our neurosurgical department between January 2006 and June 2007. During this period of time, we noticed an important increase in the surgical site infection (SSI) incidence. We conducted a case-control study to identify risk factors for these infections. Our objective was to test the hypothesis that BioGlue was one of the risk factors. Cases with infection were defined retrospectively. We included two controls per case. Study data were age, sex, time of year, in stay hospital preoperative time, length of surgery, type of surgery, surgeon, use of BioGlue, and use of duraplasty. We first performed a univariate analysis and then the significant variables were introduced in a logistic regression model. Thirty patients were defined as cases (60 controls). In multivariate analysis, risk factors were young age (p = 0.04), extended operative length (p = 0.02) and the use of BioGlue (p = 0.007). The combined use of BioGlue and Neuropatch appeared to be a significant risk factor for SSI (p = 0.002). BioGlue seems to increase the risk of SSI for patients who underwent craniotomy, especially when associated with synthetic dural graft. BioGlue triggers an intense inflammatory response, which causes wound breaches allowing bacteria to spread down in the wound, and then creates an ideal environment for bacterial growth.

Recurrent tethered cord syndrome: a novel approach for a difficult surgical condition?

Tethered cord syndrome (TCS) is a challenging disorder with a complex multifactorial etiology, which includes a thickened terminal filum, postrepair myelo­ meningocele, lipomyelomeningocele, and postoperative arachnoid adhesions.7 There are specific indications for surgery and clear surgical options including meticulous microscopic untethering of the cord, dividing the termi­ nal filum, addressing the local pathology, and dividing adhesions. The use of adjuncts such as microsurgical techniques and intraoperative monitoring with micro­ stimulation and recording has proved to be useful in re­ ducing surgical morbidity.9 Unfortunately, as is common with such troublesome pathologies, the story often doesn’t end there. A number of patients who have undergone sur­ gical treatment for TCS can present with clinical and ra­ diological evidence of recurrent tethering.7 The treatment of recurrent cases, particularly those with multiple pre­ vious procedures or in whom the underlying pathology may not allow for compete microsurgical release, is par­ ticularly challenging. Considerable surgical acumen and skill are necessary to avoid neural injury and deal with postoperative complications such as wound breakdown, CSF leakage, and further recurrence of scar tissue, which naturally contracts, leading to further tethering. There are a host of surgical techniques to avoid re­ tethering and also several treatment options available. These include simple ideas like frequent patient turning while he or she is in the prone position postoperatively and early mobilization to avoid gravitational contact between the neural structures and the dura mater, and the use of synthetic dural substitutes to minimize adhe­ sions.5 Other methods to minimize retethering include intradural retention sutures placed with subsequent du­ raplasty using autologous thoracolumbar fascia,11 and a technique of retaining the cord in the midline by fine stay sutures, between the pia mater and the conus and the anterior dura to posterior osseous elements.10 In keeping with its severity, there have even been drastic measures such as sectioning of the entire cord at a functionless lev­ el in cases of recurrent TCS.1 Other less desperate treat­ ment options include conservative, symptom­driven care, and reexploratory microsurgical untethering operations. Repeated operations for TCS have the general complica­ tions that accompany additional surgery, namely lack of an adequate vascular infrastructure, wound breakdown, and danger to the underlying neural structures. For the aforementioned reasons, alternative surgical options to manage recurrent or refractory tethered cord syndrome are welcome. In this issue of Journal of Neurosurgery: Spine, Hsieh et al.4 report on the use of ver­ tebral subtraction osteotomy to treat 2 cases of recurrent TCS. As is common with novel operative techniques, the seeds for surgical innovation were planted in a cadaveric study.2 Using a fresh­frozen human cadaver model, those authors demonstrated that vertebral subtraction at T­11 and T­12 significantly reduced tension in the terminal fi­ lum and lumbosacral nerve roots. In a natural follow­up, Hsieh et al. have elegantly shown how lateral thinking in surgery can be used to treat a complex problem. Using 2 well­described cases of repeated surgically treated TCS, they described the application of vertebral subtraction osteotomy to manage this challenging condition. The 2 patients described had undergone 4–5 previous surgeries, and in the patient in Case 2, a synthetic dural graft had previously been used in a futile attempt to prevent reteth­ ering. The initial conclusions from both cases would sug­ gest that a posterior vertebral subtraction of 15–25 mm can lead to marked reduction in terminal filum tension, equivalent of releasing 90% of neural elements. Such an attempt in a field of recurrent dense fibrosis would cer­ tainly not be without a danger to neuronal function. Although the authors should be commended for the application of lessons learned in one area of spine sur­ gery to another challenging surgical field, the approach 275 277 See the corresponding article in this issue, pp 278–286.

GORE PRECLUDE® MVP® dura substitute applied as a nonwatertight “underlay” graft for craniotomies: product and technique evaluation

Background While watertight closure of the dura is a long-standing tenet of cranial surgery, it is often not possible and sometimes unnecessary. Many graft materials with various attributes and drawbacks have been in use for many years. A novel synthetic dural graft material called GORE PRECLUDE® MVP® dura substitute (WL Gore & Associates, Inc, Flagstaff, Ariz) (henceforth called “MVP”) is designed for use both in traditional watertight dural closure and as a dural “underlay” graft in a nonwatertight fashion. One surface of MVP is engineered to facilitate fibroblast in-growth so that its proximity to the underside of the dura will lead to rapid incorporation, whereas the other surface acts as a barrier to reduce tissue adhesion to the device. Methods A series of 59 human subjects undergoing craniotomy and available for clinical and radiographic follow-up underwent nonwatertight underlay grafting of their durotomy with MVP. This is an assessment of the specific product and technique. No attempt is made to compare this to other products or techniques. Results The mean follow-up in this group was more than 4 months. All subjects have ultimately experienced excellent outcomes related to use of the graft implanted with the underlay technique. No complications occurred related directly to MVP, but the wound-related complication rate attributed to the underlay technique was higher than expected (17%). However, careful analysis found a high rate of risk factors for wound complications and determined that complications with the underlay technique could be avoided by assuring close approximation of the graft material to the underside of the dura. Conclusions MVP can be used as an underlay graft in a nonwatertight fashion. However, if used over large voids (relaxed brain or large tumor bed), “tacking” or traditional watertight closure techniques should be used. The underlay application of MVP is best applied over the convexities and is particularly well-suited to duraplasty after hemicraniectomy.

Treatment of Chiari type I malformation in patients with and without syringomyelia: a consecutive series of 66 cases

The authors describe the results of performing a standard posterior craniovertebral decompression and placement, if indicated, of a syringosubarachnoid shunt for the treatment of patients with Chiari I malformation with and without syringomyelia. This is a retrospectively analyzed consecutive series of 66 patients (mean patient age 15 years, range 1-53 years). The uniform posterior craniovertebral decompression consisted of a small suboccipital craniectomy, a C-1 laminectomy, microsurgical reduction of the cerebellar tonsils, and dural closure with a synthetic dural graft to increase the cerebrospinal fluid space at the craniocervical junction. The presence of a large syrinx, with significant thinning of the spinal cord tissue and obliteration of the spinal subarachnoid space, particularly when combined with syrinx-related symptoms, was an indication for the placement of a syringosubarachnoid shunt. In 32 patients Chiari I malformation alone was present, and 34 in patients it was present in combination with syringomyelia. Clinical findings included pain, neurological deficits, and spinal deformity. The presence of syringomyelia was significantly associated with the presence of scoliosis (odds ratio 74.4 [95% confidence interval 8.894-622.4]). All patients underwent a posterior craniovertebral decompression procedure. In 22 of the 34 patients with syringomyelia a syringosubarachnoid shunt was also placed. The mean follow-up period was 24 months (range 3-95 months). Excellent outcome was achieved in 54 patients (82%) and good outcome in 12 (18%). In no patient were symptoms unchanged or worse at follow-up examination, including four patients who initially required a second operation for persistent syringomyelia. Pain was more likely to resolve than sensory and motor deficits after decompressive surgery. Radiological examination revealed normalization of tonsillar position in all patients. The syrinx had disappeared in 15 cases, was decreased in size in 17, and remained unchanged in two. Posterior craniovertebral decompression and selective placement of a syringosubarachnoid shunt in patients with Chiari I malformation and syringomyelia is an effective and safe treatment. Primary placement of a shunt in the presence of a sufficiently large syrinx appears to be beneficial. The question of if and when to place a shunt, however, requires further, preferably prospective, investigation.

Unusual hematomas outside the spinal cord. Report of two cases.

✓ Two unusual hematomas outside the spinal cord are reported. One lay on both sides of a synthetic dural graft and was enclosed by regenerating dura. The other occurred within the leaves of the dura in a patient who had recently been under anticoagulation therapy.