Dural Reconstruction Research Articles

Operative Technique for Resection of a Ventral Transdural Retro-Odontoid Pannus: A 2-Dimensional Operative Video

Retro-odontoid pseudotumors are rare inflammatory complications of atlantoaxial instability often associated with cervical degenerative disease and rheumatoid arthritis. While propagation of these lesions has been shown to cause spinal cord compression and cervical myelopathy, intradural extension has rarely been reported. In this manuscript and 2-dimensional illustrative intraoperative video, we demonstrate cervical decompression, removal of the intradural component, and stabilization with C1-2 instrumentation using a posterior approach. A 71-year-old patient presented with progressive cervical myelopathy. Preoperative imaging demonstrated a large retro-odontoid pannus causing severe spinal cord compression and an associated contrast-enhancing intradural lesion, in the absence of obvious C1-2 instability or fractures on computed tomography scan. C1-2 posterior decompression and fusion were performed with maximally safe intradural pannus resection and ventral dural reconstruction. Postoperatively, the patient experienced significant improvement in myelopathic symptoms. Imaging demonstrated good spinal cord decompression with complete intradural pannus resection and debulking of the extradural component. Our outcome in this rare complication suggests a posterior approach may be effective in treating similar patients.

Meningioma Cell Invasion into DuraGen-Derived Dura Mater: A Case Report

Background: Dura mater infiltration is the main growth pattern of meningiomas. Local recurrence may occur in any type of meningioma, but it is more likely so in atypical meningiomas. Therefore, a wide resection of tumor cell-invaded dura mater is necessary to avoid recurrence. DuraGen® (an artificial dural substitute) can be used for dural reconstruction in meningiomas. Here, we report a rare case of a patient with atypical meningioma that invaded into the DuraGen®-derived mature dura mater. Case presentation: A 66-year-old female showed a three-time recurrence of atypical meningioma. Simpson grade I resection (en bloc tumor with autologous dura mater and DuraGen®-derived dura mater resection) was achieved at the 3rd recurrence. Collagen fibers running regularly and transversely were observed in the DuraGen®-derived dura mater resembling the autologous meningeal layer. Meningioma cell invasion, displayed by occasional EMA immunostaining, was observed in the DuraGen®-derived dura mater. Conclusions: This case indicates that meningioma cells may invade and survive in the DuraGen®-derived dura mater. Whether or not DuraGen® is not appropriate as a dural substitute remains unanswered. Further experiences are needed to validate these findings in large sample sizes.

Modified Shoelace Dural Closure with Collagen Matrix in Extended Transsphenoidal Surgery.

Extended endonasal transsphenoidal surgery (eTSS) offers a wide surgical field for various parasellar lesions; however, intraoperative high-flow cerebrospinal fluid (CSF) leakage is inevitable. Therefore, secure sellar reconstruction methods are essential to prevent postoperative CSF leakage. Although collagen matrix has been applied for dural reconstruction in neurosurgery, its suitability for application in extended eTSS remains unclear. Eighteen patients underwent modified shoelace dural closure using collagen matrix after lesionectomy via extended eTSS. In this technique, a collagen matrix, which was placed subdurally (inlay graft), was continuously sutured with both open dural edges like a shoelace. Then, another collagen matrix was placed epidurally (onlay graft), and rigid reconstruction was performed using the septal bone and a resorbable fixation mesh. Postoperative CSF leakage did not occur in 17 patients but did occur in 1 patient with tuberculum sellae meningioma. In this case, the CSF leakage point was detected just around the area between the coagulated dura and the adjacent collagen matrix. The collagen matrix harvested from this area was pathologically examined; neovascularization and fibroblastic infiltration into the collagen matrix were not detected. On the other hand, neovascularization and fibroblast infiltration into the collagen matrix were apparent on the surface of the collagen matrix harvested from the non-CSF leakage area. Our novel dural closure technique using collagen matrix could be an effective option for sellar reconstruction in extended eTSS; however, it should be applied in patients in whom normal dural edges are preserved.

Risk factors for postoperative infection after combat related head injuries

Introduction 
 The prevalence of penetrating head injuries (PBI) has increased during the latest wars making up to 37,4% of all injuries (1,2) Microbiology of modern war wounds is unique for each military conflict depending on the climatic and geographical features of the theater of combat (3,4).
 Material and methods: 
 286 patients were operatively treated after penetrating combat injury in our institution between 1991-1999. Based on the inclusion criteria: combat-related cranial injury and absence of severe abdominal or chest combat injuries, as well as their ability to report for a follow-up exam led to the inclusion of 202 patients. Initial surgical treatment included removal of devitalized soft tissue and bone fragments with craniectomy, removal of devitalized brain tissue, easily accessible intracerebral bone and metal fragments and intracranial hemathoma. All patients received the same standardized postoperative care with triple antibiotics.
 Results
 
 Infection occurred in 36 patients (17,82%). In vast majority of the cases infection occurred in the form of brain abscess 31 (86.11%), in 4 cases as meningitis (11.1%) and in 1 case as osteomyelitis and epidural infection (2.78%). Retained metal and bone fragments and postoperative liquorrhea have significant influences on occurrence of postoperative infection. 
 
 Conclusion
 
 Postoperative infection considerably increases long term functional outcome. Using advantages of minimally invasive surgical technique, neuronavigation or intraoperative imaging for removal of retained foreign bodies can reduce risk for postoperative infection with minimal risk of additional neurologic deficit. Autograft is preferable option for dural reconstruction in combat related head injuries.

Surgical Resection of Dorsal Spinal Meningiomas with the Inner Dura Layer—An Improved Preservation Technique of Spinal Dura in 40 Cases

Spinal meningiomas are the common benign tumors in intradural extramedullary spinal tumors. Simpson grade I resection is recommended to avoid tumor recurrence. However, the dura reconstruction increases a risk of cerebrospinal fluid leakage after this surgical resection. To address this concern, the inner dura layer resection and long-term surgical outcomes of this technique were designed and examined after total tumor resection to preserve the outer dura layer. This study included 40 spinal meningioma patients undergoing the outer dura layer resection between 2002 and 2019. Clinical characteristics, radiologic features, preoperative and postoperative functional states, tumor recurrence, and perioperative complications were described and evaluated. A total of 40 spinal meningioma cases with the median age of 63 years (36-81 years) were enrolled in this study. The median postoperative follow-up period of all 40 cases was 96 months (34-193 months). About 82.5% of cases were located in the thoracic spine, while 16.5% of cases were located in the cervical spine. Of the symptomatic cases, 87.5% of cases follow with satisfactory outcomes and 12.5% of cases follow with unexpected outcomes. The local spinal meningioma recurrence rate was 2.5% (1 of 40 cases). No postoperative cerebrospinal fluid leak occurred in the 40 spinal meningioma cases. A long-term postoperative follow-up indicated that this modified spinal dura preservation technique caused good neurologic improvement with rare recurrence. Therefore we recommend this improved technique may be an alternative surgical option for total resection of spinal meningiomas with favorable prognosis.

Use of Ultra-high-frequency Ultrasound for Aplasia Cutis Congenita of the Scalp.

Summary:Aplasia Cutis Congenita (ACC) in the scalp is a rare congenital malformation. The treatment for ACC with large defects involving the scalp, bone, and the dura is challenging. Local debridement of necrotic tissue is important to prevent lethal complications such as infection and meningitis. However, debridement has the risk of damaging the sagittal sinus or the dura. Recent developments in ultra-high-frequency ultrasound(US) systems provide frequencies of 70 MHz and capability resolution as fine as 30 μm, which could allow precise imaging of small and thin anatomical structures. The study aimed to describe the methods of precise evaluation of the defect in the scalp and safe debridement using ultra-high-frequency US. This is the first report on direct observation of a newborn’s brain using ultra-high-frequency US. The boy was delivered spontaneously with a large defect of the scalp and bone. After 14 days, due to signs of infection, local debridement was performed carefully under ultra-high-frequency US-based evaluation. The dura, the sagittal sinus, and the small anatomical structures such as arachnoid granulations could be observed. Because the brain herniation gradually aggravated, dural reconstruction using fascia lata and scalp reconstruction using transposition flap was performed. Finally, good skin coverage over the defects was obtained. This method minimizes the risk of damaging the sagittal sinus and the brain parenchyma, which may cause fatal complications. Although further clinical investigations will be required to confirm its efficacy, ultra-high-frequency US has the potential to be a useful device for ACC treatment.

Rapid closure technique in suboccipital decompression

ObjectiveSuboccipital decompression has been established as standard therapeutic procedure for raised intracranial pressure caused by mass-effect associated pathologies in posterior fossa. Several different surgical techniques of dural closure have been postulated to achieve safe decompression. The aim of this study was to examine the differences between fibrin sealant patch (FSP) and dural reconstruction (DR) in suboccipital decompression for acute mass-effect lesions.MethodsWe retrospectively analyzed our institutional data of patients who underwent suboccipital decompression due to spontaneous intracerebellar hemorrhage, cerebellar infarction and acute traumatic subdural hematoma between 2010 and 2019. Two different dural reconstruction techniques were performed according to the attending neurosurgeon: (1) fibrin sealant patch (FSP), and (2) dural reconstruction (DR) including the use of dural patch. Complications, operative time, functional outcome and the necessity of a ventriculoperitoneal shunt (VP Shunt) were assessed and further analyzed.ResultsOverall, 87 patients were treated at the authors’ institution (44 in FSP group, 43 in DR group). Glasgow coma scale on admission and preoperative coagulation state did not differ between the groups. Postoperatively, we found no difference in cerebrospinal fluid leakage or chronic hydrocephalus between the groups (p = 0.47). Revision rates were 2.27% (1/44 patients) in the FSP group, compared to 16.27% (7/43) in the DR group (p < 0.023). Operative time was significantly shorter in the FSP group (90.3 ± 31.0 min vs. 199.0 ± 48.8 min, p < 0.0001).ConclusionRapid closure technique in suboccipital decompression is feasible and safe. Operative time is hereby reduced, without increasing complication rates.

Characterization and Ex Vivo Application of Indocyanine Green Chitosan Patches in Dura Mater Laser Bonding.

Dura mater repair represents a final and crucial step in neurosurgery: an inadequate dural reconstruction determines dreadful consequences that significantly increase morbidity and mortality rates. Different dural substitutes have been used with suboptimal results. To overcome this issue, in previous studies, we proposed a laser-based approach to the bonding of porcine dura mater, evidencing the feasibility of the laser-assisted procedure. In this work, we present the optimization of this approach in ex vivo experiments performed on porcine dura mater. An 810-nm continuous-wave AlGaAs (Aluminium Gallium Arsenide) diode laser was used for welding Indocyanine Green-loaded patches (ICG patches) to the dura. The ICG-loaded patches were fabricated using chitosan, a resistant, pliable and stable in the physiological environment biopolymer; moreover, their absorption peak was very close to the laser emission wavelength. Histology, thermal imaging and leak pressure tests were used to evaluate the bonding effect. We demonstrated that the application of 3 watts (W), pulsed mode (Ton 30 ms, Toff 3.5 ms) laser light induces optimal welding of the ICG patch to the dura mater, ensuring an average fluid leakage pressure of 216 ± 105 mmHg, falling within the range of physiological parameters. This study demonstrated that the thermal effect is limited and spatially confined and that the laser bonding procedure can be used to close the dura mater. Our results showed the effectiveness of this approach and encourage further experiments in in vivo models.

A biomimetic triple-layered biocomposite with effective multifunction for dura repair

Dura mater defect and subsequent cerebrospinal fluid (CSF) leakage usually appear in trauma or neurosurgical procedures and are followed by a series of serious complications and even death. The use of a qualified dura mater substitute with multifunction of leakage blockade, adhesion prevention, and dura reconstruction is one of the promising treatment methods. However, even though some products have been used in the clinic, none of the substitutes achieved the required multifunction. In this study, we aimed to design and fabricate a dura repair composite with the ideal multifunction. By biomimicking the structure and component of natural dura, we applied poly(L-lactic acid) (PLLA), chitosan (CS), gelatin, and acellular small intestinal submucosa (SIS) powders to successfully prepare a triple-layered composite. Then, a series of specific devices and techniques were developed to investigate the performance. The results revealed that satisfactory structural stability could be realized under good synergistic interactions among the components. In addition, all the findings suggested that the bionic triple-layered composite showed satisfactory multifunction of leakage blockade, adhesion prevention, antibacterial property, and dura reconstruction potential, and thus, it might be a promising candidate for dura repair. Statement of significanceDeveloping qualified dura mater substitutes with multifunction of leakage blockade, adhesion prevention, and dura reconstruction is crucial for treating dura mater defect and subsequent cerebrospinal fluid (CSF) leakage that appear in trauma or neurosurgical procedures. In this study, we designed and fabricated a triple-layered dura repair biocomposite with satisfactory structural stability and desired multifunction based on biomimicking of the structure and component of natural dura. Moreover, a series of specific devices and techniques were developed to investigate the relevant performance. Overall, the developed hydrogel electrospinning system exhibited excellent advantages in achieving multifunction and could be applied widely in the future to achieve multifunctional tissue repair materials.

Primary Dural Repair Using Titanium Microclips Following Lateral Skull Base Surgery

Objective Standard techniques for primary dural repair following lateral skull base surgery are both technically challenging and time consuming without the potential for primary dural repair. Inadequate closure may result in postoperative cerebrospinal fluid (CSF) leak infectious sequalae. Traditional methods of dural repair rely on secondary obliteration of the CSF fistula. We hypothesized that the use of nonpenetrating titanium microclips may serve as a useful adjunct in primary dural repair or the establishment of an immobile repair layer following lateral skull base surgery. Methods Here, we report a novel technique for primary dural repair using nonpenetrating titanium microclips as an adjunct to standard techniques in a series of six patients with lateral skull base pathologies. Results A total of six consecutive lateral skull base tumor patients with titanium microclip dural reconstruction were included in our case series. Lateral skull base pathologies represented in this group included two jugular foramen schwannomas, one vestibular schwannoma, one petroclival meningioma, one glomus jugulare paraganglioma, and one jugular foramen chordoid meningioma. Conclusion To our knowledge, this is the first report on the use of microclips in repairing dural defects following lateral skull base surgery. Surgical outcomes for this small case series suggest that dural repair of the later skull base with nonpenetrating titanium microclips is a useful adjunct in dural repair following lateral skull base surgery.

Incidence, Clinicopathological Profile and Location - Based Outcome of Intracranial Meningiomas: 10-Year Institutional Study with Review of Literature

Abstract Intracranial meningiomas are the most common extra-axial tumors, representing 15% of all brain tumors. Arising from the arachnoid cells, and common in middle-aged women, 90% meningiomas are benign. We conducted a 10-year study on 183 cases of intracranial meningiomas and observed a lower and decreasing trend; the mean age was 43.3 years but there was also a significant incidence in young females. Parasagittal/falx (29%), sphenoid ridge, convexity meningiomas and middle cranial fossa locations were more common. Histopathologically, meningothelial meningioma was the most common. Benign (WHO I) tumors were found in above 90%, atypical (WHO II) in 5% cases, and malignant (WHO III) in &lt; 4% patients. Most patients underwent Simpsons Grade I excision (35.6%) with dural reconstruction because of late presentations. Posterior fossa meningiomas were mostly benign, while intraventricular ones were mostly malignant with highest postoperation mortality. Mortality in operated patients was 9.8% but was highest in anterior fossa tumors (12.5%).

Single Layer and Double Layer Duraplasty for the Management of Persistent Cerebrospinal Fluid Rhinorrhea Following Frontal Sinus Trauma: A Retrospective Study.

Persistent cerebrospinal fluid (CSF) rhinorrhea is an infrequent complication of frontal sinus trauma. It often require craniotomy for dural repair and obliteration of sinus with well vascularized pericranial flap. The multilayer vascularized techniques have gained popularity over the years owing to low rate of postoperative CSF leaks. The study retrospectively analyzed 25 frontal sinus trauma patients (20 males, 5 females) of mean age 32 ± 10.23 years with persistent CSF rhinorrhea from January 2011 to December 2018. All patients underwent frontal craniotomy and duraplasty was done with pericranial flap alone in 14 patients (Group I) and in combination with fascia lata graft in 11 patients (Group II). The clinical outcomes of single and double layer dural reconstruction techniques in management of CSF leak were analyzed. The size of defects ranged between 3 to 28 mm. Significant association was present between defect size and reconstruction technique with large defects underwent double layer repair. Two patients developed CSF leak following repair with pericranial flap alone. The rate of successful closure of CSF fistula was 100% with double layer reconstruction technique. However, statistically no significant association was noted between postoperative CSF leak and reconstruction technique. There was no evidence of meningitis, subdural hematoma, intracranial abscess, and mucocele formation in all patients during follow-up of 50.7 ± 23.6 months. To conclude, pericranial flap is a reliable reconstruction material for management of post traumatic frontal sinus CSF leaks. Dual flap technique that combine the use of fascia lata provides comprehensive solution of CSF fistula repair.

Individualized Sellar Floor Reconstruction Method and Nursing Strategy for the Intraoperative Cerebrospinal Fluid Leakage Caused by Neuroendoscopic Transsphenoidal Pituitary Adenoma Resection

Objective: To explore the clinical effect of and the method and nursing strategy for sellar reconstruction for intraoperative cerebrospinal fluid (CSF) leakage in pituitary adenoma resection under neuroendoscopy. Methods: The data from 20 cases of intraoperative CSF leak caused by transsphenoidal pituitary adenoma resection were retrospectively analyzed. Six patients were treated with mucosal flap and artificial dural reconstruction of sellar (simple sellar floor reconstruction). In 45 patients, autologous fat, fascia lata, and artificial dura were used to repair and reconstruct the sellar floor (multilayer sellar floor reconstruction). After the operation, all patients underwent follow-up for 6 - 24 months. Results: Fifty patients were followed up without CSF leakage. One patient was cured after leakage of CSF through the lumbar cistern 1 month after discharge. Conclusion: For patients with CSF leakage during neuroendoscopic transsphenoidal pituitary adenoma resection, individualized sellar floor reconstruction should be adopted according to the degree of CSF leakage and the size of the sellar floor defect. Strict nursing measures can effectively prevent CSF leakage and reduce postoperative complications.

Long-term outcomes of spinal meningioma resection with outer layer of dura preservation technique

Spinal meningioma is a common benign intradural spinal tumor. It has been reported that the local recurrence rate after surgical resection increases with longer follow-up duration. Simpson grade 1 resection could reduce the risk of recurrence, but this procedure needs dural reconstruction, which would cause cerebrospinal fluid (CSF) leakage or iatrogenic spinal cord injury. Saito et al. reported dura preservation technique to reduce the risk of CSF leakage, in which the meningioma together with the inner layer of the dura is removed and the outer layer is preserved for simple dural closure. The long-term outcomes with this technique have never been investigated. In this study, we retrospectively analyzed the data of 38 surgically treated patients (dura preservation technique, 12 patients; Simpson grade 2 resection, 26 patients) to assess the long-term recurrence rate (mean, 121.5 months; range, 60–228 months). The local recurrence rate in the dura preservation group was 8.3% (1 of 12 cases), which was similar to that in Simpson grade 2 resection group (2 of 26 cases [7.7%]). Although this case series did not indicate the significant difference in the recurrence rates between the dura preservation group and Simpson grade 2 group, we consider that this technique still has advantages for surgically less invasiveness in terms of dural reconstruction which is necessary for Simpson grade 1 and higher possibility of complete resection of tumors compared with Simpson grade 2 resection.

Growing skull fractures of the orbital roof: a multicentric experience with 28 patients.

Growing skull fracture (GSF) is a rare condition that may complicate pediatric head trauma. Patients may present with delayed-onset neurological manifestations. This study aims to highlight the different presentations, methods of evaluation, treatment modalities, and outcomes in patients with orbital roof GSF. This retrospective multicentric cohort study reviewed the hospital records of children with GSF who presented at the Craniomaxillofacial Plastic Surgery Department, and Neurosurgery Department with Otorhinolaryngology Department (Maxillofacial unit), from 2011 to 2020. The collected data included age, gender, delay, manifestations, findings of imaging techniques, surgical treatment, complications, and satisfaction of patients' parents. Twenty-eight patients with orbital roof GSF were included in this study. Most of the patients (82.1%) were boys, and the mean (SD) age was 5 (2) years old. Head trauma was caused by falls in all cases. Clinical manifestations included eyelid swelling (75%), pulsatile proptosis (25%), headache (17.9%), and seizures (10.7%). The mean (SD) diameter of bony defects was 24.3 (8.7) mm. Duraplasty alone was performed in 57.1%, while dura-cranioplasty was done in 42.9% of patients. Dural reconstruction was done using pericranial graft in 82.1% and artificial grafts in 17.9% of patients. Most of the parents (95%) were absolutely satisfied. No mortalities or recurrence of symptoms were recorded. The median follow-up period after surgery was 3.9years. Orbital roof GSF should be considered among the differential diagnoses in pediatric patients with history of head trauma presenting with ocular and/or neurological manifestations. Duraplasty is mandatory in all cases, whereas cranioplasty is required mainly in cases with large bony defects more than 25mm. Prognosis in most patients was good both subjectively and objectively.

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.

Incidence of complications following non-watertight dural reconstruction with a non-suturable, absorbable collagen matrix onlay graft in elective cranial surgery

Background: Collagen matrices are effective duraplasty grafts with increasing acceptability. However, little evidences exits for dural reconstruction utilizing monolayer collagen matrix onlay graft in a non-watertight fashion. Purpose of our retrospective analysis was to advance our understanding of the use of semisynthetic collagen as dural substitute in elective cranial surgery.Methods: A consecutive series of sixty patients who underwent elective cranial surgery, where non-watertight dural reconstructions were done with a non-suturable, absorbable collagen matrix onlay graft, has been analysed retrospectively.Results: Overall, the most common indication for duraplasty was tumor resection (93.3%). CSF leak rate was 10.0%. Incidence of aseptic meningitis was 8.3% and all cases has been resolved with steroids alone. Similarly, postoperative surgical site infection rate was 8.3%. Incidence of pseudomeningocele in follow-up was 6.7%. Only in one case (1.7%), permanent CSF (cerebrospinal fluid) diversion was needed due to troublesome CSF leak with associated hydrocephalus.Conclusions: Semisynthetic, monolayer collagen matrix used as an onlay dural graft is a simple, yet an attractive alternative in duraplasty due to their easy handling, lower surgical time, and high biocompatibility, where primary dural closure is undesirable or not feasible. Our study provides greater insight into non-water tight duraplasty procedure. However, further study is needed to determine the optimal strategy for dural reconstruction. Data from this study may be used to compare alternative methods of dural reconstruction in elective cranial surgery.

Ten-Year Experience of Dural Reconstruction Using a Collagen Matrix Inlay Graft in Posterior Fossa Surgery: A Propensity Score–Matched Study

Considering that primary watertight dural closure is not always possible following posterior fossa surgery, several methods of dural reconstruction were proposed to reduce the risk of cerebrospinal fluid (CSF) leakage. This study aimed to evaluate the efficacy of collagen matrix inlay graft compared with other techniques in a propensity score-matched cohort. Between 2000 and 2019, 176 consecutive patients who underwent posterior fossa surgery were enrolled. Of these, 103 patients underwent dural reconstruction with collagen matrix inlay graft (inlay group). After propensity score matching, 67 pairs were derived. The primary outcome was the development of CSF leakage. Pseudomeningocele and surgical site infection were also investigated. Median follow-up period was 53.9 months. None of the patients in the inlay group had CSF leakage; however, leakage was evident in 5 patients (6.8%) who underwent dural reconstruction without a collagen matrix inlay graft (no-inlay group; P= 0.011). Pseudomeningocele was noted in 1 (1.4%) patient in the no-inlay group, while surgical site infection was noted in 3 (3.0%) patients in the inlay group and 4 (5.5%) patients in the no-inlay group. None of the surgical site infections were related to the use of the inlay graft. After propensity score matching, CSF leakage was still prevalent in the no-inlay group (P= 0.042). Dural reconstruction using a collagen matrix inlay graft efficiently reduces CSF leakage after posterior fossa surgery and does not increase the risk of postoperative infection and inflammation. It seems to be a feasible option for dural reconstruction.

Unveiling the tale of the tail: an illustration of spinal dysraphisms.

Spinal dysraphism is an umbrella term describing herniation of meninges or neural elements through defective neural arch. They can be broadly categorized into open and closed types. MRI is the investigation of choice to study neural abnormalities and to assess the severity of hydrocephalus and Chiari malformation. Knowledge of the embryology of these disorders is valuable in correctly identifying the type of dysraphism. The aim of surgery is untethering and dural reconstruction. Accurate depiction of the abnormal anatomy in cases of spinal dysraphism is of utmost importance for surgical management of these patients. MRI makes this possible due to its excellent soft tissue contrast resolution and multiplanar capability, allowing the radiologist to evaluate the intricate details in small pediatric spinal structures. Imaging enlightens the surgeons about the status of spinal cord and other associated abnormalities and helps detect re-tethering in operated cases. Besides, antenatal surgery to repair myelomeningoceles has made detection of open dysraphisms on fetal MRI and antenatal ultrasound critical. The purpose of this review is to describe the development of spine, illustrate the myriad imaging features of open and closed spinal dysraphisms, and enlist the reporting points the operating surgeon seeks from the radiologist.

Minimally Invasive Repair of Tegmen Defects Through Keyhole Middle Fossa Approach to Reduce Hospitalization

The middle fossa craniotomy for tegmen defect repair provides wide access. This approach often requires temporal lobe manipulation, lumbar drain placement, and longer recovery. We describe a keyhole middle fossa approach with a simple titanium skull base repair that allows for wide access with no temporal lobe manipulation and does not require lumbar drain placement, which results in a dramatic reduction in hospital length of stay. A retrospective review was performed on 14 consecutive patients with spontaneous cerebrospinal fluid (CSF) otorrhea. Each patient underwent a keyhole middle fossa approach followed by multilayer dural repair with titanium mesh "gull wing" skull base reconstruction. Postoperative measures included operative time, length of hospital stay, CSF leak recurrence, and surgical complications (seizures, hemorrhage, aphasia, infection). The average age of the patients was 60.7±12.7 years old, and average body mass index was 32.8 ± 7.9 kg/m2. Nine of the patients were female. The average operative time was 103 ± 32.8 minutes. The average hospital length of stay was 1.4 days. There were no cases of postoperative CSF otorrhea, meningitis, aphasia, or seizures. There were no recurrences over a mean follow-up of 20.3 months (range: 5-48 months). A minimally invasive keyhole middle fossa approach with a multilayer dural reconstruction including titanium mesh "gull wing" skull base repair provides a quick, effective treatment for a broad spectrum of tegmen defects and meningoencephaloceles. This exposure and reconstruction technique do not require the use of a lumbar drain and result in minimal hospitalization.