Intradural Surgery Research Articles

Dural closure for the treatment of superficial siderosis

Superficial siderosis (SS) of the CNS is a rare disease caused by repeated hemorrhages in the subarachnoid space. The subsequent deposition of hemosiderin in the brain and spinal cord leads to the progression of neurological deficits. The causes of bleeding include prior intradural surgery, carcinoma, arteriovenous malformation, nerve root avulsion, and dural abnormality. Recently, surgical treatment of SS associated with dural defect has been reported. The authors of the present report describe 2 surgically treated SS cases and review the literature on surgically treated SS. The patients had dural defects with fluid-filled collections in the spinal canal. In both cases, the dural defects were successfully closed, and the fluid collection was resolved postoperatively. In one case, the neurological symptoms did not progress postoperatively. In the other case, the patient had long history of SS, and the clinical manifestations partially deteriorated after surgery, despite the successful dural closure. In previously reported surgically treated cases, the dural defects were closed by sutures, patches, fibrin glue, or muscle/fat grafting. Regardless of the closing method, dural defect closure has been shown to stop CSF leakage and subarachnoid hemorrhaging. Successfully repairing the defect can halt the disease progression in most cases and may improve the symptoms that are associated with CSF hypovolemia. However, the effect of the dural closure may be limited in patients with long histories of SS because of the irreversibility of the neural tissue damage caused by hemosiderin deposition. In patients with SS, it is important to diagnose and repair the dural defect early to minimize the neurological impairments that are associated with dural defects.

Understanding the need for spinal registries: Lee Breakwell reviews the importance of registries in spinal research and explains why the British Association of Spinal Surgeons (BASS) has decided to set up its own registry

A registry is an organised collection of data that allows interrogation and analysis of that information. Information regarding operations has always been collected and interpreted for patient care purposes, and advances in computing and data storage have significantly aided this process. The Swedish Hip Register, begun in 1979, has shown that prospective, disciplined data collection can offer huge benefits in improving patient care through identifying trends and early problems [1]. It has also led the way with a lumbar spine database, which was followed by Spine Tango—the first multinational European registry. With the advent of surgeon league tables, and the drive towards Value Based Health Care, individuals, and the healthcare system has a duty to collect, store and interpret data, to facilitate an uplift in quality whilst maintaining appropriate downwards pressure on the increasing costs [2]. Therefore, BASS resolved to institute a British Spine Registry (BSR), both in terms of clinical expediency and the availability of secure yet accessible web-based technology. The registry was conceived as a surgeon-driven database, with patient-centred information, to enable assessments of certain procedure types, and their outcome. A subcommittee was formed, led by Ashley Cole, consultant spinal surgeon, Northern General Hospital, Sheffield, UK, to define the dataset and to create a tender process. Bluespier International was the successful company, and has worked with the BASS registry committee to design and launch the BSR on the Amplitude platform. The main aims of the BSR design were to create a secure, comprehensive database, to allow individual surgeons and their teams to collect prospective data in a convenient and timely manner. To achieve this, a web-based solution was developed, ensuring that all users could access the BSR wherever, and whenever they wished. In order that patient data security issues were appropriately addressed, the BSR has been registered with the UK bodies the Information Commissioners Office, the Healthcare Quality Improvement Partnership, and the Record of Central Returns. In addition, NHS IT experts have reviewed the security policies, and data storage technology. From a design perspective the BSR has been built around the concept of patient pathways. All patients’ data can be collected with options for lumbar and cervical degenerative, trauma, tumour, infection, deformity and intradural surgery. Details of the presenting clinical symptoms, and signs, plus the resulting operative data, including the use of spinal implants, can then be added to define a treatment episode. The Association of British Healthcare Industries (ABHI) has enabled listing of a majority of the available spinal implants, such that an overview of usage, and ultimately outcomes on a national scale can be achieved for the very first time. A major feature of the BSR is patient reported outcome measures (PROM). Each patient pathway allows collection of data, using validated scores such as the Oswestry Disability Index, and EuroQOL 5D. This data can be collected in a multitude of ways dependent upon local practice, but use of the associated Amplitude Patient Portal for direct electronic input is recommended. BASS launched the BSR at Britspine 2012 (2–4 May, Newcastle Upon Tyne, UK) and the registry is now available to all registered users. The British Scoliosis Society (BSS) is now supporting the project, ensuring the BSR is available to any surgeon who is a member of either organisation. Once online surgeon registration is complete, individuals can nominate co-workers who can obtain access for improved data collection. Currently there are over 200 registered surgeons, and over 3,000 patients enrolled in the registry. Individuals will be able to interrogate their data, with surgical outcomes, including complication rates by procedure type. The societies will be for the first time able to create real-time accurate population data on spinal surgery in the UK. This simply has to be the way forward. For registration, downloads, assistance or more information, see: http://www.bsrcentre.org.uk. Lee Breakwell is a consultant orthopaedic spinal surgeon at Northern General Hospital, Sheffield, UK, and is audit lead for BASS, and the BSR.

The impact of fluorescence guidance on spinal intradural tumour surgery

5-Aminolevulinic acid (5-ALA)-based fluorescence-guided surgery was shown to be beneficial for cerebral malignant gliomas. Extension of this technique for resection of meningiomas and cerebral metastasis has been recently evaluated. Aim of the present study is to evaluate the impact of fluorescence-guided surgery in spinal tumor surgery. Twenty-six patients with intradural spinal tumors were included in the study. 5-ALA was administered orally prior to the induction of anesthesia. Intraoperative, 440 nm fluorescence was applied after exploration of the tumor and, if positive, periodically during and at the end of resection to detect tumor-infiltrated sites. Tumors of WHO grade III and IV were found in five patients. In detail intra- or perimedullary metastasis of malignant cerebral gliomas was found including glioblastoma WHO grade IV (n = 2), anaplastic astrocytoma WHO grade III (n = 1), anaplastic oligoastrocytoma WHO grade III (n = 1). In addition, one patient suffered from a spinal drop metastasis of a cerebellar medulloblastoma WHO grade IV. Tumors of WHO grade I were diagnosed in 18 patients: Eight cases of meningioma (two recurrences), six cases of neurinoma, one neurofibroma, two ependymoma and one plexus papilloma. At least, benign pathologies were histologically proven in three patients. All four spinal metastasis of malignant glioma (100 %), seven of eight meningiomas (87.5 %) and one of two ependymoma (50 %) were found to be ALA-positive. The present study demonstrates that spinal intramedullary gliomas and the majority of spinal intradural meningiomas are 5-ALA positive. As a surgical consequence, especially in intramedullary gliomas, the use of 5-ALA fluorescence seems to be beneficial.

Remote Cerebellar Hemorrhage after Intradural Disc Surgery

We report a rare case of remote cerebellar hemorrhage after intradural disc surgery at the L1-2 level. Two days after the spine surgery, patient complained unexpected headache, dizziness, nausea and vomiting. From the urgently conducted brain CT, it was reported that the patient had cerebellar hemorrhage. Occipital craniotomy and hematoma evacuation was performed, and hemorrhagic lesion on the right cerebellum was effectively removed. After occipital craniotomy, the patient showed signs of improvement on headache, dizziness, nausea and vomiting. He was able to leave the hospital after two weeks of initial operation without any neurological deficit. Remote cerebellar hemorrhage following spinal surgery is extremely rare, but may occur from dural damage of spinal surgery, accompanied with cerebrospinal fluid leakage. Early diagnosis is particularly important for the optimal treatment of remote cerebellar hemorrhage.

Is closed-suction drainage necessary after intradural primary spinal cord tumor surgery?

The efficacy of closed-suction drainage in primary intradural spinal cord tumor surgery has not been addressed. We investigated whether closed-suction drainage is essential after primary intradural spinal cord tumor surgery. From January 2003 to October 2011, 169 consecutive patients with primary intradural spinal cord tumors operated by a single surgeon were selected. Closed-suction drainage was inserted in patients before August 2007, but was not used after August 2007. After removal of tumor and meticulous hemostasis, the opened dura was closed and made watertight using 4-0 silk with interrupt suture and 1.0cm(3) of surgical glue was applied in common. Closed-suction drainage was inserted below the muscular fascia in 75 patients (group I, M:F=39:36; 46.20±15.63years) and was not inserted in 94 patients (group II, M:F=46:48; 51.05±14.89years). Neurological deficit precluding ambulation did not occur in all patients. Between group I and II, there were no significant differences in body mass index (22.75±3.16 vs. 23.51±3.22kg/m(2); p=0.13), laminectomy level (2.45±1.46 vs. 2.33±1.91; p=0.65), operation time (260.65±109.08 vs. 231.52±90.08min; p=0.06), estimated intraoperative blood loss (456.93±406.62 vs. 383.94±257.25cm(3); p=0.18), and hospital stay period (9.25±5.01 vs. 9.35±5.75days; p=0.91). Two patients in group I underwent revision surgery due to wound problems, while revision surgery was not performed in group II (p=0.20). Closed-suction drainage may not be essential after primary intradural spinal cord tumor surgery.

Is Closed-Suction Drainage Necessary for Intradural Primary Spinal Cord Tumor Surgery?

Is Closed-Suction Drainage Necessary for Intradural Primary Spinal Cord Tumor Surgery?

Minimally invasive lumbar intradural extramedullary tumor resection.

Intradural, extramedullary schwannomas have long been treated with open midline incision, laminectomy, and dural opening to expose and resect the lesion. While this technique is well established, today new surgical techniques can be utilized to perform the same procedure while minimizing pain, size of incision, and trauma to adjacent tissues. In cases of intradural surgery, minimally invasive surgery limits the degree of soft tissue disruption. As a result, there is significant decreased dead space within the surgical cavity that may decrease the rate of CSF leak complications. Minimally invasive techniques have continuously improved over the years and have reached a point where they can be used for intradural surgeries. In this case presentation, we demonstrate a minimally invasive approach to the lumbar spine with resection of an intradural schwannoma. Surgical techniques and the nuances of the minimally invasive approach to intradural tumors compared to the standard open procedure will be discussed. The video can be found here: http://youtu.be/XXrvAIq_H48 .

Beyond superficial siderosis

Superficial siderosis (SS) of the CNS results from hemosiderin deposition in the subpial layers of the brain and spinal cord.1,–,3 The hemosiderin deposition results from recurrent and persistent bleeding into the subarachnoid space and has a predilection for the cerebellum, spinal cord, and cranial nerves I, II, and VIII. Patients often present in adulthood with slowly progressive gait (less commonly appendicular) ataxia, and sensorineural hearing impairment. The presentation may mimic a degenerative cerebellar disorder. A remote history of injury or intradural surgery (frequently involving the posterior fossa) is common. Often decades elapse between the presumed inciting event and development of symptoms attributable to SS. MRI is the investigation of choice. The typical MRI finding is a characteristic, marginal, confluent T2 hypointensity on the surface of the brain and cord (figure 1, A–I).3 This is better appreciated on gradient-echo sequences. With widespread use of MRI, presymptomatic cases are being diagnosed and it is difficult to be certain about the true incidence of the disorder. In recent years SS has also been recognized as an MRI marker of cerebral amyloid angiopathy.4 Red blood cells or xanthochromia may be seen on CSF studies. Despite extensive investigations (brain and spine MRI, CT myelogram, magnetic resonance angiography, cerebrospinal angiography), the cause of bleeding is often not apparent. Figure 1 Neuroimaging findings in superficial siderosis (SS) (A–I) All images are from a 76-year-old woman with SS. T2-weighted axial (A–E, H, I) and sagittal (F, G) brain (A–E), cervical spine (F, H), and thoracic spine (G, I) MRIs show the characteristic confluent T2 hypointensity due to hemosiderin deposition along the cerebellar folia (A: arrows), around the medulla (A: dotted arrow), pons (B), midbrain (C), along the sylvian fissures (D), interhemispheric fissure (E), and along (F, G) and around (H, I) the cervical (F, H) and thoracic (G, …

Harvey Cushing's Operative Treatment of Metastatic Breast Cancer to the Central Nervous System in the Early 1900s

A review of the surgical cases of Harvey Cushing, MD, at The Johns Hopkins Hospital provided insight into his early work treating breast cancer metastasis to the central nervous system (CNS). At the time, neurologic surgery was in its infancy. Metastases of breast carcinoma to the CNS were recognized; however, many surgeons of the era adhered to a general principle of not operating in these situations. The Johns Hopkins Hospital surgical records from 1896 to 1912 were reviewed. Four cases in which Cushing treated patients with a history of breast cancer who were diagnosed as having CNS metastasis were selected for further study. Cushing performed surgery on 4 patients with suspected CNS metastasis in the early 1900s. For a spinal metastasis, Cushing performed a laminectomy and intradural exploratory surgery. His treatments in cerebral cases sought to relieve increased intracranial pressure through decompression. He resected the lesions when they could be located. From the start of his career as a neurosurgeon, Cushing chose to perform surgery on patients with suspected CNS metastasis in an attempt to palliate some of their symptoms. Although his patients did not survive long after the procedures, they did experience temporary relief of symptoms that likely encouraged Cushing's continued operations in such situations and laid the foundation for future therapies for these patients.

Results of the Prospective, Randomized, Multicenter Clinical Trial Evaluating a Biosynthesized Cellulose Graft for Repair of Dural Defects

After intradural cranial surgery, a dural substitute is often required for dural closure. Although preferred, limitations of autograft include local availability and additional surgical site morbidity. Thus, allografts, xenografts, and synthetics are frequently used. To report 6-month results of a randomized, controlled trial of a biosynthesized cellulose (BSC) composed duraplasty device compared with commercially available dural replacements. A total of 99 patients (62 BSC; 37 control) were treated on protocol, using a 2:1 (BSC:control) blocked randomization schedule. Physical examinations were performed pre- and postoperatively within 10 days and at 1, 3, and 6 months. Magnetic resonance imaging was performed preoperatively and at 6 months. The primary study endpoint was the absence of pseudomeningocele and extracerebral fluid collection confirmed radiographically and the absence of cerebrospinal fluid fistula at 6 months. At 6 months, the primary hypothesis, noninferiority of the BSC implant compared with the control group, was confirmed (P = .0206). Overall success was achieved by 96.6% of BSC and 97.1% of control patients. No significant difference was revealed between treatment groups for surgical site infection (P = 1.0000) or wound healing assessment (P ≥ .3685) outcomes, or radiologic endpoints (P ≥ .4061). Device strength and seal quality favored BSC. This randomized, controlled trial establishes BSC as noninferior to commercially available dural replacement devices. BSC offers a hypothetical advantage concerning prion and other infectious agent exposure; superior handling qualities are evident. Longer term data are necessary to identify limitations of BSC and its potential equivalence to the gold standard of pericranium.

Transient Allodynia Following Caudal Lipoma Excision: A Case Report

Allodynia is the sensation of pain due to non-painful stimuli. It usually occurs due to destructive lesions of the spinal cord or peripheral nerves. Allodynia following intradural lipoma surgery has been reported previously. We herein report a case of allodynia developed after microsurgical caudal lipoma excision without associated spinal cord injury.

Congenital Cervical Tethered Cord in an Adult: Utility of Spinal Diffusion Tensor MR Imaging

Tethering of the spinal cord rarely occurs in the cervical region [1]. A few case reports established trauma, previous intradural surgery, spinal cord infection and congenital abnormalities to be associated with tethering of the cervical spinal cord [2] [3] [4] [5] [6] [7] [8] [9] [10]. Spinal dysraphisms such as congenital dermal sinus tracts (DST) are often associated with spinal cord tethering but most commonly occur in the lumbosacral region [1] [2]. DST are epithelium-lined tracts that extend from the skin to the deeper neural tissue due to an incomplete separation of the cutaneous ectoderm from the underlying neuroectoderm during embryonic development [11]. In order to avoid neurological and infectious complications, early surgery including intradural exploration and complete resection of the tract has been recommended [1] [2] [3]. Usually DST and other congenital abnormalities are recognized at birth or in early childhood by typical cutaneous findings. Therefore, presentation in adulthood is extremely rare. Here, we present the case of a 30-year-old female with a progressive symptomatic cervical tethered cord due to an unusual congenital abnormality resembling a regressed DST. In patients with a tethered cord, conventional MR imaging frequently fails to detect stretch-induced pathological changes of the myelon despite the presence of spinal cord dysfunction. As recent developments in neuroimaging suggest that diffusion tensor MR imaging (DTI) may be more sensitive to detect spinal cord injuries [12] [13], we included DTI in our preoperative workup and found abnormal fiber orientation in the region of cervical cord tethering.

The Use of Indocyanine Green Videography for Intraoperative Localization of Intradural Spinal Tumors

Prospective. To characterize the role of indocyanine-green videography in the intraoperative localization of intradural spinal tumors. Correct intraoperative localization of intradural spinal tumors as well as tailored dural opening is essential in surgery and can be demanding in some instances. We investigated the role of indocyanine green (ICG) videography to correctly localize intradural, spinal tumors. We report a series of 30 patients with intradural spinal tumors, in which (hemi-)laminectomy or extended laminotomy was followed by ICG videography to determine intradural tumor margins (injection of intravenous ICG, visualization with operating microscope in combination with an additional, fluorescent light source). Tumor projection was verified after dural opening, and surgical resection was continued thereafter. Imaging was conducted without complications in all cases. Identification of the tumor margins before dural opening was achieved in 28 cases (93%), either by tumor enhancement or absence of ICG uptake in relation to the surrounding spinal cord or nerve roots. In 1 case, ICG videography helped to correct the previously determined level of exposure and led to cranial extension of the bony exposure. No significant contrast enhancement was seen in 2 patients who demonstrated a small lesion ventrolaterally to the cervical spinal cord. ICG videography represents a helpful tool to localize the position of intraspinal, intradural tumors, which are lateral or dorsal to the spinal cord or nerve roots. Bony exposure can be optimized before dural incision. Positioning and length of dural incision may be tailored to reduce the incidence of complications such as leakage of cerebrospinal fluid and/or accidental fiber damage.

Spinal drop metastasis from grade I skull base chondrosarcoma

Chondrosarcoma of the skull base is a rare tumour with a good prognosis following surgical resection. We describe a patient with low-grade chondrosarcoma of the skull base with intradural extramedullary spinal metastases. A 31-year-old female with grade 1 chondrosarcoma involving the cavernous sinus, sphenoid wing and clivus presented at age 19. The tumour was subtotally excised at initial surgery and over the following 4 years, 3 subsequent resections were undertaken for tumour progression followed by proton beam radiotherapy to the residual tumour. The patient re-presented with cervical radiculopathy 7 years later. MRI showed multiple, intradural extramedullary spinal drop metastases. Following surgical excision of the symptomatic lesion, histological diagnosis was confirmed as a mixed hyaline/myxoid grade 1 chondrosarcoma. Patients with skull base chondrosarcoma with intradural extension should have whole spine imaging as part of long-term monitoring to exclude drop metastases, particularly after intradural surgery.

SUPERFICIAL SIDEROSIS: SEALING THE DEFECT

Superficial siderosis (SS) of the CNS results from chronic hemorrhage into the subarachnoid space with hemosiderin deposition in the subpial layers.1,2 The clinical presentation includes progressive ataxia and deafness. Some patients have a history of trauma or intradural surgery. Despite extensive investigations, a cause of bleeding is frequently elusive. An extra-arachnoid, intraspinal, or intracranial CSF collection, often longitudinally extensive, is sometimes identified in spinal neuroimaging in SS.1–6 A dynamic CT myelogram can identify the dural defect connecting the intrathecal space with the fluid-filled collection.4 The precise mechanism of bleeding is unknown. Rarely CSF hypovolemia accompanies SS.6 Increased CSF RBC count may be seen in CSF hypovolemia.7 These observations have led to the suggestion that repairing the dural defect may halt bleeding and prevent deficit progression.6 Clinical confirmation of this hypothesis is lacking. We describe a patient with SS and CSF hypovolemia due to a CSF leak. Repair of the leak was accompanied by clinical improvement and resolution of neuroimaging and CSF abnormalities. ### Case report. A 64-year-old man was evaluated for a 3-year history of progressive imbalance and 10-year history of decreased hearing. His history was remarkable for childhood poliomyelitis. Over the years he had multiple horse riding-related falls. Twenty years earlier he had a C4-C7 laminectomy for right upper limb weakness. On examination, he had mild …

Nasoseptal Flap Takedown in Endoscopic Skull Base Surgery

Objective 1) Understand the importance of the nasoseptal flap in endoscopic skull base reconstruction. 2) Learn the techniques and limitations of nasoseptal flap takedowns and reuse during second stage and revision endoscopic skull base surgery. Methods Prospective consecutive analysis of CSF leak outcomes with nasoseptal flap takedown and reuse during endoscopic skull base surgery at a tertiary care skull base center. Results 16 consecutive cases of nasoseptal flap takedown and reuse for endoscopic endonasal intradural tumor surgery were collected prospectively and evaluated for CSF leak outcomes. 10 of these cases were planned second-stage surgeries and 6 were for revision or recurrent tumors. All 16 cases had intradural tumor extension and intra operative CSF leak. 15 of 16 had successful skull base reconstruction without postoperative CSF leak. One patient required revision endoscopic CSF leak repair and bolstering of the defect with a fat graft on post operative day 3. No flap deaths occurred. Endoscopic skull base reconstructive techniques and limitations of flap takedowns are discussed. Conclusions As the limits of endoscopic skull base surgery increases, the limits of endoscopic skull base reconstruction must also increase. The pedicled nasoseptal flap has shown great promise (4% leak rate in over 300 nasoseptal flap skull base reconstructions) at the time of the initial resection. This report illustrates the ability to takedown and reuses the nasoseptal flap in revision cases with great success (94%) and minimal additional nasal morbidity.

“GASKET-SEAL” WATERTIGHT CLOSURE IN MINIMAL-ACCESS ENDOSCOPIC CRANIAL BASE SURGERY

Transnasal endoscopic cranial base surgery is a novel minimal-access method for reaching the midline cranial base. Postoperative cerebrospinal fluid leak remains a persistent challenge. A new method for watertight closure of the anterior cranial base is presented. To achieve watertight closure of the anterior cranial base, autologous fascia lata was used to create a "gasket seal" around a bone buttress, followed by application of a tissue sealant such as DuraSeal (Confluent Surgical, Inc., Waltham, MA). The gasket-seal closure was used to seal the anterior cranial base in a series of 10 patients with intradural surgery for suprasellar craniopharyngiomas (n = 5), planum meningiomas (n = 3), clival chordoma (n = 1), and recurrent iatrogenic cerebrospinal fluid leak (n = 1). Lumbar drains were placed intraoperatively in five patients and remained in place for 3 days postoperatively. After a mean follow-up period of 12 months, there were no cerebrospinal fluid leaks. The gasket-seal closure is an effective method for achieving watertight closure of the anterior cranial base after endoscopic intradural surgery.

SUPERFICIAL SIDEROSIS AND CSF HYPOVOLEMIA: THE DEFECT (DURAL) IN THE LINK

Superficial siderosis (SS) of the CNS is caused by repeated hemorrhage into the subarachnoid space with resultant hemosiderin deposition in the subpial layers of the brain and spinal cord.1 The commonest neurologic manifestation is that of slowly progressive gait ataxia and impaired hearing. A remote history of injury or intradural surgery is common. An intraspinal fluid collection of variable dimensions is a very frequently noted imaging finding in SS of the CNS, although this has gone unrecognized until recently.1–3 Nerve root cysts related to root avulsion1 or posterior fossa cysts are recognized accompaniments.4,5 The high prevalence of these cystic collections suggests that bleeding from a dural defect may be responsible for SS. Particularly in the presence of longitudinally extensive extra-arachnoid intraspinal collections, a dynamic CT-myelogram may be required to identify the defect site.3 Repair of the dural defect has been associated with resolution of the CSF xanthochromia or red blood cells, decrease in the fluid collection, and in some cases clinical stability.1 Dural defects with meningeal …

Positive End-expiratory Pressure Reduces Pneumocephalus in Spinal Intradural Tumor Surgery

We tested the hypothesis that 5 cm H2O of positive end-expiratory pressure (PEEP) reduces the incidence of pneumocephalus in patients who undergo spinal intradural tumor surgery. Fifty-three ASA I to III patients who underwent thoracolumbar intradural tumor surgery between the years 2003 and 2006 were included in this study. All patients received propofol, fentanyl, and cisatracurium for induction of the anesthesia. Maintenance was provided by propofol infusion and, oxygen (50%) and air (50%). Group I (n=28) did not receive PEEP whereas group II (n=25) received PEEP as 5 cm H2O. Cranial computerized tomography was taken at 8 hours after the surgery and cases were evaluated for pneumocephalus using BAB Bs200ProP Image System software. Pneumocephalus areas between 0.03 and 4.24 cm2 were observed in 9 patients, 8 in group I and 1 patient in group II at the 8th postoperative hour, at various localizations. There were no neurologic findings in other patients except for 2 patients in group I who presented with headache and mental status change. Although the cerebrospinal fluid leakage is minimal, N2O is not used and the patients are well hydrated, pneumocephalus with neurologic deficits may occur in patients undergoing microsurgical spinal intradural tumor surgery in prone position. In our study, we showed that using 5 cm H2O PEEP perioperatively reduced the risk of pneumocephalus. However, more cases must be studied to support this hypothesis.

Guidance of the Microanatomical Landmarks in Expanded Anteromedial Triangle Approach at Intradural Transcavernous Surgery

Guidance of the Microanatomical Landmarks in Expanded Anteromedial Triangle Approach at Intradural Transcavernous Surgery