Arachnoid Opening Research Articles

Surgical Management of Chiari 1.5 in Children: A Truly Different Disease?

Background: In patients with Chiari 1.5 malformation (CM1.5), a more aggressive disease course and an increased association with craniovertebral junction (CVJ) anomalies has been suggested. The best management of this subgroup of patients is not clearly defined, also due to the lack of specific series elucidating this anomaly's peculiar characteristics. Methods: We evaluated a series of 33 patients (25 females, 8 males; mean age at surgery: 13 years) fulfilling the criteria for Chiari 1.5 diagnosis who underwent posterior fossa decompression and duraplasty (PFDD) between 2006 and 2021. Results: Headache was present in all children, five presented central apnea, five had dysphagia, and three had rhinolalia. Syringomyelia was present in 19 (58%) children. Twenty patients (61%) showed various CVJ anomalies, but only one child presented instability requiring arthrodesis. The mean tonsil displacement below the foramen magnum was 19.9 mm (range: 12-30), without significant correlation with the severity of symptoms. Syringomyelia recurred or was unchanged in three patients, and one needed C1-C2 fixation. The headache disappeared in 28 children (84%). Arachnoid opening and tonsil coagulation or resection was necessary for 19 children (58%). Conclusions: In our pediatric CM series, the need for tonsil resection or coagulation was higher in CM1.5 children due to a more severe crowding.

Incidence and management of postoperative pseudomeningocele and cerebrospinal fluid leak after Chiari malformation type I decompression.

The optimal surgical management of Chiari malformation type I (CM-I) remains controversial and heterogeneous. The authors sought to investigate patient-specific, technical, and perioperative features that may affect the incidence of CSF-related complications including pseudomeningocele and CSF leak at their institution. The authors performed a single-center, retrospective review of all adult patients with CM-I who underwent posterior fossa decompression. Patient demographics, operative details, and perioperative factors were collected via electronic medical record review. The authors performed Fisher's exact test and independent Student t-tests for categorical and continuous variables, respectively. Univariate regression analysis was performed to determine odds ratios. A multivariable regression analysis was performed for those factors with p < 0.10 or large effect sizes (OR ≥ 2.0 or ≤ 0.50) by univariate analysis. The STROBE guidelines for observational studies were followed. A total of 59 adult patients were included. Most patients were female (78.0%), and the mean body mass index was 32.2 (± 9.0). Almost one-third (30.5%) of patients had a syrinx on preoperative imaging. All patients underwent expansile duraplasty, of which 47 (79.7%) were from autologous pericranium. Arachnoid opening for fourth ventricular inspection was performed in 26 (44.1%) cases. CSF-related complications were identified in 18 (30.5%) of cases. Thirteen (22.0%) patients required readmission and 11 (18.6%) required intervention such as wound revision (n = 5), wound revision with CSF diversion (n = 4), CSF diversion alone (n = 1), or blood patch (n = 1). Three (5.1%) patients required permanent CSF diversion. Male sex (OR 3.495), diabetes mellitus (OR 0.249), tobacco use (OR 2.53), body mass index more than 30 (OR 2.45), preoperative syrinx (OR 1.733), autologous duraplasty (OR 0.331), and postoperative steroids (OR 2.825) were included in the multivariable analysis. No factors achieved significance by univariate or multivariable analysis (all p > 0.05). The authors report a single-center, retrospective experience of posterior fossa decompression for 59 adults with CM-I. No perioperative or technical features were found to affect the CSF-related complication rate. More standardized practices within centers are necessary to better delineate the true risk factors and potential protective factors against CSF-related complications.

Suturing of the Arachnoid Membrane for Reconstruction of the Cisterna Magna: Technical Considerations

Postoperative cerebrospinal fluid (CSF) fistula following cranial or spinal surgery is associated with increased morbidity and mortality. To prevent CSF fistulas, various techniques have been described. Here, we describe the arachnoid membrane continuous-running suture technique in cisterna magna reconstruction for preventing postoperative CSF leakage. After craniotomy and dural opening, the incision of the arachnoid of the cisterna magna was performed using a diamond blade. To prevent the arachnoid from drying out and shrinking during surgery, it was periodically irrigated with warm saline solution. Posterior fossa surgery was performed. When closing the membranes, the arachnoid membrane was closed with the running-suture technique. After the first surgical knot was made in the cranial end of the arachnoid opening, continuous suturing with a 2-mm distance between the stitches was performed without stretching them. After every 3 stitches, the free end of the thread was pulled gently along the suturing axis, and the edges of the arachnoid were closed. After the arachnoid edges were approximated, the surgical knot was tied. Watertight closure was checked byperforming the Valsalva maneuver at the end of the surgery. No CSF leakages were observed after surgery. Arachnoid membrane suturing seems to be safe and effective in preventing postoperative CSF leakage and CSF-related complications. Using continuous running suturing alone, without any sealant, might beeffective in cases with untraumatized arachnoid membrane.

Controlled arachnoid opening to aid endoscopic trans-sphenoidal extrarachnoidal dissection of pituitary macroadenoma

Objectives The arachnoid often bulges prematurely during surgical excision of large pituitary tumors obscuring the deeper regions and crevices preventing total excision. Pushing the arachnoid may not be helpful and may tear it inadvertently and extensively leading to complications. We have described controlled arachnoid opening in large pituitary macroadenomas during the final stages of excision to gain access to the hidden portions and compared our results to the conventional technique Patients and methods Patients with pituitary macroadenoma of Hardy’s III and KNOSP II in whom arachnoid had bulged prematurely were considered for study. They were grouped temporally. In first group (n = 12), the arachnoid was pushed to retrieve the tumor and in the second group (n = 10) it was punctured to aid resection. The extent of resection was assessed on postoperative scans, and complications in both groups, were noted. Results In the first group where arachnoid was pushed to retrieve tumor, Gross Total Resection (GTR) could be achieved in 5 patients. Inadvertent large arachnoid tear occurred in 3 patients of which, 2 developed CSF Rhinorrhoea. No patient had neurovascular injury. In the second group, GTR could be achieved in all without any added complications. Conclusion Deliberate needle puncture and controlled drainage of CSF from arachnoid that bulges prematurely while endoscopic Transsphenoidal surgery for large pituitary tumors is a safe and effective method to gain access to the hidden portions of tumor to achieve GTR.

Clinical and radiological outcomes of arachnoid-preseving suboccipital decompression for adult chiari I malformation with and without syringomyelia

ObjectiveTo share our experience related to clinic and radiologic outcomes of patients with Chiari I malformation. Patients and MethodsThis retrospective study evaluated surgical outcome of 48 patients who underwent posterior fossa decompression and duraplasty with arachnoid-preservation technique February 2010 and February 2019. Clinic and radiologic outcomes at long-term follow-up were provided. ResultsSurgery led to satisfactory outcomes in both clinic and radiologic measures. The majority of patients (66.7%) in the follow-up period informed us that their symptoms significantly improved. In 14 patients (29.2%), the symptoms were gone totally and no complaining was reported to us. Syringomyelia was encountered in 21 patients (43.7%) on pre-operative MRI. During long-term, significant improvement (syrinx segments were remarkably reduced in diameter) in syrinx size was noted in 16 of the 21 patients (76.1%). In 5 of the 21 patients (23.8), complete improvement, that is, syrinxes were totally collapsed, was seen. Surgery-related complications occurred in a total of 5 patients (10.4%). ConclusionIn our experience, we found decompressive craniectomy wide enough with duraplasty without arachnoid opening is safe and successful in patients with CIM. Complication rate is low and arachnoid preserving technique should be performed by experienced neurosurgeons.

Common Practice in the Management of Dural Closure: An Italian Questionnaire

The optimal management of dural closure is unclear; therefore, we aimed to survey current common practices among Italian practitioners. The Delphi method was used to achieve a consensus on dura mater closing techniques in Italy. A steering committee decided 3 major topics to be investigated: pre- and postoperative conditions associated with cerebrospinal fluid (CSF) leak, indications to perform watertight dural closure, and dural closure technique. A questionnaire containing 12 statements was then submitted to Italian neurosurgeons. The response rate was 60%. Among 60 items, 36 reached a positive consensus, 5 reached a negative consensus, and 19 did not reach consensus. Intrathecal hypertension, arachnoid opening, previous treatments, spinal incidental durotomy, wide size of osteo-dural defect, and lack of nasoseptal flap were considered major risk factors for CSF leak. Early mobilization, avoidance of stress maneuvers, and use of CSF external drainage were considered to reduce CSF leak rate. Italian neurosurgeons always attempt watertight dural closure, ideally with monofilament nonabsorbable sutures. Both autologous and heterologous dural grafts are used. Among dural sealants, fibrin glues are preferred, which are used most commonly in transsphenoidal surgery. This study elucidates the areas of consensus and uncertainty on dural closure management among a group of Italian neurosurgeons. It provides reliable and comparable data for the investigation of the departments' daily practice in dural closure. Given the lack of solid evidence, there is a need for further comparative studies of dural repair strategies.

Chiari 1 Malformation Surgery: Comparing Non-violation of the Arachnoid versus Arachnoid Opening and Thermocoagulation of the Tonsils

Evidence is lacking concerning the myriad surgical techniques for type 1 Chiari malformation. This study evaluated the impact of arachnoid violation with tonsil thermocoagulation during surgical craniovertebral junction decompression. The evaluation included aspects of the neurologic examination and parameters of cerebrospinal fluid flow on magnetic resonance imaging during preoperative and postoperative periods. All patients underwent craniovertebral junction decompression and opening of the dura mater. Patients were divided into 2 study groups. Patients in group 1 did not undergo arachnoid violation. Patients in group 2 underwent tonsil manipulation and systematic opening of the fourth ventricle outlet. There were 16 patients enrolled in each group (total of 32 patients). Regarding clinical improvement, there were no significant differences between groups in the postoperative period. Group 2 had more adverse events (relative risk 2.45, 95% confidence interval 1.55-3.86). In terms of cerebrospinal fluid flow parameter analyses, patients in group 1 achieved better results (P < 0.05). For treatment of symptomatic type 1 Chiari malformation, craniovertebral junction decompression with arachnoid preservation (i.e., without tonsillar manipulation) seems more suitable than the addition of arachnoid opening and thermocoagulation of the tonsils.

Spinal Extradural Arachnoid Cyst: A Case Report

Spinal extradural arachnoid cyst is a rare cause of spinal cord compression resulting in spinal myelopathy. We report a case of 12-year-old boy diagnosed with extradural thoracolumbar spinal arachnoid cyst presenting with back and leg pain, progressive left leg weakness, mild muscular atrophy and difficulty in walking. The boy presented with progressive weakness of distal left lower limb and intermittent claudication. MRI-scan revealed an extramedullary non-enhancing fluid signal intensity lesion with cord compression. The patient underwent zip laminectomy from T9 - L2 level using electric drill and total excision of the extradural cyst, microsurgical repair of the dural defect, followed by laminoplasty, using ethibond sutures was done. Intraoperative finding revealed an elongated 10 cm long cystic lesion with finger-like projections extending in the extradural space from T9 - L2 level, causing significant compression and displacement of the cord. The cyst was in communication with intradural subarachnoid space with a small ovoid-shaped arachnoid opening at T12 level on the left side adjacent to T11 nerve root. The postoperative course was uneventful and patient was discharged on postoperative day seven. Neurologically, the patient showed some improvement. On one-month follow-up, there was remarkable improvement in movement of the lower limbs. He was able to walk independently without limping gait; however, he still had mild weakness in his left leg (4+/5).Nepal Journal of Neuroscience, Volume 15, Number 2, 2018, Page: 49-54

Navigation-Linked Heads-Up Display in Intracranial Surgery: Early Experience.

BACKGROUNDThe use of intraoperative navigation during microscope cases can be limited when attention needs to be divided between the operative field and the navigation screens. Heads-up display (HUD), also referred to as augmented reality, permits visualization of navigation information during surgery workflow.OBJECTIVETo detail our initial experience with HUD.METHODSWe retrospectively reviewed patients who underwent HUD-assisted surgery from April 2016 through April 2017. All lesions were assessed for accuracy and those from the latter half of the study were assessed for utility.RESULTSSeventy-nine patients with 84 pathologies were included. Pathologies included aneurysms (14), arteriovenous malformations (6), cavernous malformations (5), intracranial stenosis (3), meningiomas (27), metastasis (4), craniopharygniomas (4), gliomas (4), schwannomas (3), epidermoid/dermoids (3), pituitary adenomas (2) hemangioblastoma (2), choroid plexus papilloma (1), lymphoma (1), osteoblastoma (1), clival chordoma (1), cerebrospinal fluid leak (1), abscess (1), and a cerebellopontine angle Teflon granuloma (1). Fifty-nine lesions were deep and 25 were superficial. Structures identified included the lesion (81), vessels (48), and nerves/brain tissue (31). Accuracy was deemed excellent (71.4%), good (20.2%), or poor (8.3%). Deep lesions were less likely to have excellent accuracy (P = .029). HUD was used during bed/head positioning (50.0%), skin incision (17.3%), craniotomy (23.1%), dural opening (26.9%), corticectomy (13.5%), arachnoid opening (36.5%), and intracranial drilling (13.5%). HUD was deactivated at some point during the surgery in 59.6% of cases. There were no complications related to HUD use.CONCLUSIONHUD can be safely used for a wide variety of vascular and oncologic intracranial pathologies and can be utilized during multiple stages of surgery.

Evaluation of operative procedures for symptomatic outcome after decompression surgery for Chiari type I malformation

The wide spectrum of symptoms and radiographic findings in patients with Chiari I malformation makes the decision to proceed with intervention controversial. We evaluated symptomatic outcomes using diverse surgical techniques in 104 patients who underwent decompression surgery. The symptoms of most patients improved. Patients with syringomyelia showed less symptomatic improvement; however, syringomyelia was not associated with postoperative symptomatic worsening. Durotomy was performed in 97.1% and arachnoid opening was performed in 60.6% with visualization of the fourth ventricle in 51.9% of patients. Neither arachnoid opening nor fourth ventricle visualization was associated with the clinical outcome. Duraplasty was performed in 94.2% of patients. A Chiari plate was used in 13.4% of patients and was associated with favorable outcomes. Use of postoperative steroids or muscle relaxants was not associated with outcome. Syringomyelia showed a 62.5% improvement rate on postoperative MRI. In conclusion, bony decompression and dural opening are important aspects of Chiari I surgery, with symptomatic improvement observed in most patients.

Evaluation of Moyamoya Disease in Sickle Cell Anemia Patients After Encephaloduroarteriosynangiosis

Abstract 1059▪▪This icon denotes a clinically relevant abstract Background:Moyamoya disease is a progressive cerebrovascular complication of sickle cell anemia characterized by collateral arterial formation in response to progressive stenosis of the large intracranial arteries. Despite chronic transfusions, moyamoya is associated with a high risk of stroke recurrence. Encephaloduroarteriosynangiosis (EDAS) is a surgical technique used to reestablish or augment cerebral perfusion in patients with moyamoya disease. However, evidence for its efficacy in SCA patients is limited. We initiated a prospective study to determine whether EDAS is safe and increases blood flow to ischemic areas of brain in SCA patients with moyamoya. Methods/Results:SCA patients who had complete or partial obstruction of the dICA with progression to moyamoya disease were eligible for EDAS. Progressive cognitive decline, dystonia and persistent seizures were also factors influencing eligibility. Seven SCA patients (age: median 16yrs, range 4–23yrs; sex: 5F/2M ) with moyamoya disease underwent encephaloduroarteriosynangiosis (EDAS) procedures between 3/2007 and 9/2010. All 7 patients were regularly transfused for a history of stroke or MRA-documented ICA stenosis. Complete or partial obstruction of the dICA with moyamoya changes was detected on MRA scans and confirmed by cerebral angiography. Bilateral (n = 2) or unilateral (n = 5) encephaloduroarteriosynangiosis procedures in which the superficial temporal artery is transplanted through a small craniotomy with dural and arachnoid opening and sutured to the pia were performed. Perfusion MR-weighted imaging was performed pre- and post-operatively to evaluate changes in relative cerebral blood volume and time to peak enhancement. Results:All patients have remained free of neurovascular complications and have had no new ischemic changes on MRI with an average follow-up of 26 months. All patients subjectively reported improvement in overall well-being. A decrease in the frequency of headaches (n=1), resolution of seizures (n=2) and improved gait (n=1) were also observed. Collateral anastomoses between external and internal carotid arteries were established by MRA in all patients. All 4 patients who had pre and post-procedure MRA perfusion imaging showed a reduction in the delay of time to peak enhancement in the affected territory after EDAS. Conclusion:Our results indicate that EDAS is a safe and effective surgical procedure to re-establish blood flow to ischemic brain tissue in patients with SCA who develop moyamoya disease. MRA perfusion imaging may be a useful tool to evaluate improved perfusion status after EDAS. Further examination of neuropsychologic correlates, such as executive function, with EDAS procedures in these patients is presently underway. Disclosures:Vichinsky:Novartis: Research Funding; Apotex: Research Funding.

Modified bilateral subtemporal decompression for resistant slit ventricle syndrome

Slit ventricle syndrome (SVS) remains a major problem for early shunted children. Several conservative and surgical treatment paradigms have been suggested; however, there is no consensus on the optimal surgical treatment. We present our experience using bilateral subtemporal decompressions with dura and arachnoid opening for the treatment of a subgroup of children with severe and resistant SVS. Fifteen children with severe and resistant SVS underwent a modified bilateral subtemporal craniectomy, with dura and arachnoid opening. Their clinical and radiological data were retrospectively reviewed. Seven (46.6%) patients had a complete recovery from their symptoms with a follow-up of 5.9 ± 2.6years.The remaining eight (53.3%), underwent additional surgeries. Four (26.6%), had a single proximal shunt revision after dilatation of their ventricles. Following these procedures these four children are well and stable with a follow-up of 1.8 ± 2years. The other four had further cranial vault expansion, one of which was followed by a proximal shunt revision. Thus, 11 of these 15 patients (73.4%) had a very good outcome, attributable to this technique, with a mean follow-up of 4.5 ± 3years. Modified bilateral subtemporal decompression with dura and arachnoid opening yields a high cure rate for severe and resistant slit ventricle syndrome. Proximal shunt revision may be safely performed in a subset of patients that dilate their ventricles following the procedure. Further cranial expansion may be reserved for children with recurrent SVS symptoms who do not respond to STD and remain with very small ventricles.

Multiple burr hole surgery as a treatment modality for pediatric moyamoya disease

Objective:To re-emphasize that indirect revascularization surgery alone, where multiple burr holes and arachnoid openings are made over both cerebral hemispheres, is beneficial in the treatment of moyamoya disease (MMD) in children.Clinical Presentation:We report a 10-year-old boy who presented with complaints of episodic headache for the last 5 years. At the peak of his headache he had visual disturbances and acute onset weakness of left-sided limbs, recovering within a few minutes. He had no focal neurological deficits. Radiological investigations revealed abnormal findings, demonstrating the features of MMD.Surgical Management:He underwent bilateral multiple burr holes, dural and arachnoid opening over the frontal, parietal and temporal regions of each hemisphere. The elevated periosteal flap was placed in contact with the exposed brain through each burr hole.Results:On 6-months follow-up he had only one episode of transient ischemic attack. Postoperative four vessel angiogram demonstrated excellent cerebral revascularization around the burr hole sites, and single photon emission computerized tomography imaging showed hypoperfusion in the right temporo-occipital area suggestive of an old infarct with no other perfusion defect in the rest of the brain parenchyma.Conclusion:In children with MMD this relatively simple surgical technique is effective and safe, and can be used as the only treatment without supplementary revascularization procedures. This procedure can be done in a single stage on both sides and the number of burr holes made over each hemisphere depends on the extent of the disease.

Effect of Multiple Cranial Burr Hole Surgery on Prevention of Recurrent Ischemic Attacks in Children with Moyamoya Disease

Moyamoya disease (MMD) is an uncommon cerebrovascular disorder characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches. Direct and indirect bypass techniques have been devised with the aim of promoting neoangiogenesis. The current study aimed to investigate the role of multiple cranial burr hole (MCBH) operations in the prevention of cerebral ischemic attacks in children with MMD. Seven children suffering from progressive MMD were submitted to the MCBH and arachnoid opening technique. Ten to 20 burr holes were drilled in the fronto-temporo-parieto-occipital area of each hemisphere in each patient, depending on the site and extent of the disease. All patients were evaluated pre- and postoperatively by means of Barthel index (BI), CT, MR, angio-MR, and angiography. Patients had no recurrence of ischemic attacks postoperatively. Neoangiogenesis was observed in both hemispheres. One patient developed a persistent subdural collection after surgery, thus requiring placement of a subdural-peritoneal shunt. Postoperative BI was statistically significantly improved (P=0.02). This report suggests that MCBH for revascularization in MMD is a simple procedure with a relatively low risk of complications and effective for preventing cerebral ischemic attacks in children. In addition, MCBH may be placed as an adjunct to other treatments for MMD.

Arachnoid Opening With or Without Dural Graft Recommended for Treatment of Chiari I Malformation

Arachnoid Opening With or Without Dural Graft Recommended for Treatment of Chiari I Malformation

Encephaloduroarteriosynangiosis with bifrontal encephalogaleo(periosteal)synangiosis in the pediatric moyamoya disease: the surgical technique and its outcomes.

To increase the blood flow of the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) territories, we modified the "ribbon" procedure in combination with encephaloduroarteriosynangiosis (EDAS). This is referred to as "EDAS with bifrontal encephalogaleo(periosteal)synangiosis (EGS)." The surgical technique, clinical outcomes, complications, extent of revascularization, and changes in CBF in 67 pediatric MMD patients were retrospectively reviewed. The excellent and good clinical recovery rates were 57% and 31%. The rate for complete disappearance of TIA was 63%. All the bifrontal EGS made abundant collateral vessels in the ACA territory. When the EDAS with bifrontal EGS was performed in the first operation, collaterals of EGS sites developed more on the contralateral side of the EDAS. The arachnoid opening of the medial frontal lobe in the EGS site had no effect on the results. There was a positive correlation between the clinical outcome and the extent of angiographic revascularization. Improvements in the CBF and the reserve in ACA territory were observed in 57%. EDAS with bifrontal EGS resulted in excellent revascularization in both the MCA and ACA territories. The clinical and hemodynamic results were also excellent. This procedure may be an effective and safe surgical modality for the prevention of ischemia in the whole territory of the anterior circulation of the brain in pediatric MMD.

Intra-operative premature rupture of the cerebral aneurysms. Analysis of the causes and management.

The causes and management of intra-operative premature rupture are analysed and discussed. During the past 6 years, the authors, performed 398 consecutive direct surgical interventions for ruptured cerebral aneurysms. Intra-operative premature rupture is defined as a rupture which occurs before the securing of the parent arteries or the neck of the aneurysm and is out of control, at least temporarily. The causes and management were retrospectively analyzed by reviewing video tape recordings. Intra-operative premature ruptures which met the above definition occurred in 24 cases (6.0%). The causes were as follows: 1.) dural opening and arachnoid opening (8.3%), 2.) haematoma removal (12.5%), 3.) brain retraction (16.7%), 4.) aneurysm dissection (62.5%). A double suction technique was used to control bleeding and haemostasis with a small piece of cotton or a temporary clip, performed in 20 cases (83.3%). However, in cases with premature rupture immediately after the dural or arachnoid opening, the extension of the haematoma into the subarachnoid space resulted in severe brain swelling and partial resection of the brain had to be done to secure temporary clipping. The double suction technique and primary haemostasis using a small piece of cotton or temporary clip resulted in good outcome even in cases with premature rupture. However, very early premature rupture also occurred although its incidence was extremely rare. The removal of part of the brain can secure the working space but the outcome was poor.