Laminoplasty with tented duraplasty for Hirayama disease.

BACKGROUND: Hirayama disease (HD) is a characterized by progressive amyotrophy of the upper limbs due to a forward displacement of the cervical dura during neck flexion. METHODS: Unlike other treatment options aiming at preventing cervical flexion (e.g., collar or arthrodesis), laminoplasty with tented duraplasty addresses dural dysplasia. Technically, the procedure consists in enlarging the dural sac by performing an expansile duraplasty that is secured to the yellow ligaments, in association with an open-book laminoplasty. CONCLUSION: Laminoplasty with tented duraplasty is a surgical option addressing the cause of HD to prevent further neurological deterioration while preserving cervical motion.

Diagnosis and treatment of Chiari malformation and syringomyelia in adults: international consensus document.

BACKGROUND: Syringomyelia and Chiari malformation are classified as rare diseases on Orphanet, but international guidelines on diagnostic criteria and case definition are missing. AIM OF THE STUDY: to reach a consensus among international experts on controversial issues in diagnosis and treatment of Chiari 1 malformation and syringomyelia in adults. METHODS: A multidisciplinary panel of the Chiari and Syringomyelia Consortium (4 neurosurgeons, 2 neurologists, 1 neuroradiologist, 1 pediatric neurologist) appointed an international Jury of experts to elaborate a consensus document. After an evidence-based review and further discussions, 63 draft statements grouped in 4 domains (definition and classification/planning/surgery/isolated syringomyelia) were formulated. A Jury of 32 experts in the field of diagnosis and treatment of Chiari and syringomyelia and patient representatives were invited to take part in a three-round Delphi process. The Jury received a structured questionnaire containing the 63 statements, each to be voted on a 4-point Likert-type scale and commented. Statements with agreement <75% were revised and entered round 2. Round 3 was face-to-face, during the Chiari Consensus Conference (Milan, November 2019). RESULTS: Thirty-one out of 32 Jury members (6 neurologists, 4 neuroradiologists, 19 neurosurgeons, and 2 patient association representatives) participated in the consensus. After round 2, a consensus was reached on 57/63 statements (90.5%). The six difficult statements were revised and voted in round 3, and the whole set of statements was further discussed and approved. CONCLUSIONS: The consensus document consists of 63 statements which benefited from expert discussion and fine-tuning, serving clinicians and researchers following adults with Chiari and syringomyelia.

Clinical characteristics and long-term surgical outcome of spinal myxopapillary ependymoma: a French cohort of 101 patients.

PURPOSE: Myxopapillary ependymoma (MPE) is the most frequent tumor affecting the medullary conus. The surgical therapeutic management is still debated and only few studies have focused on the postoperative clinical outcome of patients. This study aimed to demonstrate long-term postoperative outcome and to assess the predictive factors of recurrence as well as the clinical evolution of these patients. METHODS: From 1984 to 2019, in four French centers, 101 adult patients diagnosed with MPE were retrospectively included. RESULTS: Median age at surgery was 39 years. Median tumor size was 50 mm and lesions were multifocal in 13% of patients. All patients benefited from surgery and one patient received postoperative radiotherapy. Gross total resection was obtained in 75% of cases. Sixteen percent of patients presented recurrence after a median follow-up of 70 months. Progression free survival at 5 and 10 years were respectively estimated at 83% and 79%. After multivariable analysis, sacral localization, and subtotal resection were shown to be independently associated with tumor recurrence. 85% of the patients had a favorable evolution concerning pain. 12% of the patients presented a postoperative deterioration of sphincter function and 4% of motor function. CONCLUSION: Surgery alone is an acceptable option for MPE patients. Patients with sacral location or incomplete resection are at high risk of recurrence and should be carefully monitored.

Cognitive versus virtual reality simulation for evaluation of technical skills in neurosurgery.

OBJECTIVE: Simulation is gaining momentum as a new modality of medical training, particularly in acute care settings such as surgery. In the present study, the authors aimed to compare individual cognitive skills with manual abilities as assessed by virtual reality (VR) simulation among neurosurgical residents. METHODS: Participants were asked to complete a multiple-choice questionnaire assessing their surgical abilities regarding three basic neurosurgical procedures (endoscopic third ventriculostomy, cranial meningioma, and lumbar laminectomy). They subsequently performed these same three procedures on a VR simulator (NeuroTouch). RESULTS: The authors found that cognitive scores correlated with self-evaluation of surgical experience and autonomy. On the contrary, VR simulation, as assessed by NeuroTouch automated scoring, did not reflect participants' cognitive or self-evaluation of their surgical proficiency. CONCLUSIONS: The results of this study suggest that neurosurgical education should focus as much on cognitive simulation (e.g., careful planning and critical appraisal of actual procedures) as on VR training of visuomotor skills.

Paragangliomas of the spine: a retrospective case series in a national reference French center.

INTRODUCTION: Primary paragangliomas (PG) of the spine are extremely rare entities. The present study reviews our experience over a period of 30 years. METHODS: This is a retrospective, single center, observational study. Patients surgically treated for a spinal PG with confirmed anatomopathological diagnosis were included. The McCormick classification was used as a reference for clinical evaluation. Follow-up MRI and clinical assessment took place at 6 weeks, 3 months, 6 months, and 1 year after surgery and on yearly basis after. RESULTS: Six cases have been operated in our institution. The mean age was 37.8 (median 35.5, 30-53). The mean follow-up period was 9.6 years (median 9.5, 1-23). Preoperative duration of symptoms varied between a few hours to 4 years. Low back pain was most common sign. One presented with hemorrhage and acute onset of paraplegia. All patients underwent single surgery, with the exception of one case, which had two surgeries on the same anatomical site and a third surgery on another location of the same tumor type. Preoperatively, McCormick scale was I in four cases, and II and IV in one case, respectively. Postoperatively, all patients in McCormick I retained the same class; one patient in McCormick II passed to McCormick III; the case in McCormick IV recovered to McCormick II. Five of eight surgeries achieved total resection, while two surgeries accomplished a partial microsurgical excision and one a gross total resection. Three patients had spinal leptomeningeal dissemination. Two of them benefited from extended spine radiotherapy, while the other of a "wait-and-scan" policy. Spinal leptomeningeal dissemination was stable in all patients at last follow-up. CONCLUSION: We consider surgery as primary treatment in all PG. In our experience, preoperative diagnosis is difficult and caution must be taken to perioperative course in these cases. We do not routinely perform postoperative radiation if there is a residual tumor. We regularly perform clinical and radiological follow-up, so as to be able to document recurrent cases, which have been reported even up to 30 years after primary surgical excision.

Transsphenoidal resection for pituitary adenoma in elderly versus younger patients: a systematic review and meta-analysis.

INTRODUCTION: Pituitary adenomas (PA) are common intracranial tumors. In the context of the aging of the population, the question is whether postsurgical outcomes are comparable to the younger ones. The primary objective of the present study was to review published resection and recurrence rates after transsphenoidal resection. The secondary aim was to evaluate visual improvement and complication rates. METHODS: The authors searched PubMed and Medline databases, of published English series, with no time frame limit, evaluating outcomes of transsphenoidal resection in populations aged more or less than 65, 70, and 80 years. We performed a systematic review and meta-analysis. RESULTS: Median overall resection rates for younger population was 70.7% (range 54-76.8) and for elderly one was 65.7% (range 16.6-78.2) (two-sample t test, p = 0.35). The only statistically significant difference for gross total resection rates (GTR) favored patients aged less than 80 (p = 0.01). There was no statistically significant difference among recurrence rates. There was a statistically significant difference for visual improvement favoring patients aged more than 80 (p = 0.03). For the age groups of less versus more than 70, there was a statistically significant difference for overall complication rate favoring younger groups (p < 0.05). CONCLUSION: Present data shows GTR rates favoring younger patients. Recurrence rates remain similar over the mean follow-up period. Moreover, visual improvement favors patients aged more than 80. Overall complication rates favor patients younger than 70, which might be also related to additional comorbidities, frequently present in seniors. Transsphenoidal surgery is safe and effective even for older patients.

Surgical resection of medulla oblongata hemangioblastomas: outcome and complications.

OBJECT: The purpose of this study was to analyze the surgical outcome and complications of a single-center series of medulla oblongata (MO) hemangioblastomas. METHODS: We retrospectively reviewed the medical charts of all medulla oblongata hemangioblastomas operated on at our institution between 1996 and 2015. All patients had a pre- and postoperative MRI and a minimum follow-up of 6 months. Patients were scored according to the Karnofsky Performance Scale (KPS) and McCormick Scale at the moment of admission, discharge and the last follow-up. RESULTS: Thirty-one surgical procedures were performed on 27 patients (16 females and 11 males). The mean age was 33 years, and 93 % of patients had von Hippel Lindau (VHL) disease. Three patients experienced very complicated postoperative courses, with one case ending in the death of the patient. Two patients required tracheostomy. According to McCormick's classification, 7 (23 %) of the 31 operations resulted in aggravation and 23 (74 %) in no change. Considering the seven patients with aggravation at discharge, four patients (60 %) returned to their preoperative status, one (14 %) improved but remained below his preoperative McCormick grade and two (29 %) did not improve. At last follow-up, KPS was ameliorated in 53 %, stable in 40 % and worsened in 7 % of cases. CONCLUSION: Surgery of medulla oblongata hemangioblastomas is a challenging procedure characterized by an acceptable morbidity. Transient morbidity is not negligible even if the long-term outcome is in most cases favorable. A compromised neurological condition seems to be the best predictor of unfavorable outcome.

Management and Outcome of Recurring Low-Grade Intramedullary Astrocytomas.

Intramedullary astrocytomas (IMAs) are the second most frequent intramedullary tumors in adults. Low-grade IMAs (LG-IMA, WHO grade I and II) carry a better prognosis than high-grade IMAs (HG-IMAs). However, adjuvant treatment of LG-IMAs by radiotherapy (RT) and/or chemotherapy (CT) as well as treatment of tumor recurrences remains controversial. The aim of our study was to evaluate the postoperative outcome of LG-IMAs and the management of recurring tumors. We retrospectively reviewed a series of patients operated on for IMA from 1980 to 2022 in a single neurosurgical department. We retrieved 40 patients who received surgery for intramedullary astrocytomas, including 30 LG-IMAs (22 WHO grade I; 5 WHO grade II; 3 "low-grade") and 10 HG-IMAs (4 WHO grade III; 5 WHO grade IV; 1 "high-grade"). Of the patients with LG-IMAs, the extent of surgical resection was large (gross or subtotal resection >90%) in 30% of cases. Immediate postoperative radiotherapy and/or chemotherapy was proposed only to patients who underwent biopsy (n = 5), while others were initially followed-up. Over a median follow-up of 59 months (range = 13-376), 16 LG-IMA (53.3%) recurred with a mean delay of 28.5 months after surgery (range = 3-288). These included seven biopsies, five partial resections (PR), four subtotal resections (STR) but no gross total resections (GTR). Progression-free survival for LG-IMAs was 51.9% at 3 years and 35.6% at 5 and 10 years; overall survival was 96.3% at 3 years; 90.9% at 5 years and 81.9% at 10 years. There were no significant differences in terms of OS and PFS between WHO grade I and grade II tumors. However, "large resections" (GTR or STR), as opposed to "limited resections" (PR and biopsies), were associated with both better OS (p = 0.14) and PFS (p = 0.04). The treatment of recurrences consisted of surgery alone (n = 3), surgery with RT and/or CT (n = 2), RT with CT (n = 3), RT alone (n = 2) or CT alone (n = 2). In conclusion, although LG-IMAs are infiltrating tumors, the extent of resection (GTR or STR), but not WHO grading, is the main prognostic factor. The management of recurring tumors is highly variable with no conclusive evidence for either option.

A Staged Approach for Surgical Management of Basilar Invagination.

BACKGROUND AND OBJECTIVES: Patients with basilar invagination (BI) can be treated with several surgical options, ranging from simple posterior decompression to circumferential decompression and fusion. Here, we aimed at examining the indications and outcomes associated with these surgical strategies to devise a staged algorithm for managing BI. METHODS: We conducted a retrospective cohort study in 2 neurosurgical centers and included patients with a BI, as defined by a position of the dens tip at least 5 mm above the Chamberlain line. Other craniovertebral junction anomalies, such as atlas assimilation, platybasia, and Chiari malformations, were documented. C1-C2 stability was assessed with a dynamic computed tomography scan. RESULTS: We included 30 patients with BI with a mean follow-up of 56 months (min = 12, max = 166). Posterior decompression and fusion (n = 8) was only performed in cases of obvious atlanto-axial instability (eg, increased atlanto-dental interval or hypermobility on flexion/extension), while anterior decompression (transoral or transnasal) was reserved to patients with lower cranial nerves deficits (eg, swallowing dysfunction) and irreducible anterior compression (n = 9). Patients with posterior signs (eg, Valsalva headaches) or myelopathy but without C1-C2 instability nor anterior signs were managed with an isolated foramen magnum decompression, with or without duraplasty (n = 13). Complications were more frequent for combined procedures, including neurological deterioriation (n = 4) and tracheostomy (n = 2), but reinterventions were more likely in patients undergoing posterior decompression alone (n = 3). CONCLUSION: Patient selection is key to determine the appropriate surgical strategy for BI: In our experience, combined approaches are only needed for patients with irreducible and symptomatic anterior compression, while fusion should be restricted to patient with obvious signs of atlanto-axial instability. Other BI patients can be managed by foramen magnum decompression alone to minimize surgical morbidity.

Spinal Anterior Dural Dissection: Moving From Differential to Unifying Diagnosis.

BACKGROUND AND OBJECTIVES: Cerebrospinal fluid (CSF) collections extending longitudinally at the anterior aspect of the spinal dura have been reported in association with various conditions and under multiple names. The aim of this study was to report cases associated with brachial amyotrophy (BA) and examine its relationship with other clinical variants. METHODS: We conducted a retrospective cohort study including patients who presented with a motor deficit of the upper limbs and an anterior interdural CSF collection on spinal MRI. We performed a systematic review of the literature to include cases revealed by BA. RESULTS: Seven patients presenting with BA and a confirmed dural dissection on spinal MRI were included. All patients were male with a slowly progressing history of asymmetrical and proximal motor deficit of the upper limbs. Chronic denervation affecting mostly C5 and C6 roots was found on electroneuromyography. Spinal MRI demonstrated an anterior CSF collection dissecting the interdural space and exerting a traction on cervical motor roots. Dynamic computed tomography myelogram localized the dural defect every time it was performed (4/7 cases), and surgical closure was possible for 3 patients, leading to resolution of the collection. Literature review yielded 18 other published cases of spinal dural dissections revealed by BA, including 4 in association with spontaneous intracranial hypotension and 4 others in association with superficial siderosis. CONCLUSION: We propose a unifying diagnosis termed "spinal anterior dural dissection" (SADD) to encompass spinal dural CSF collections revealed by BA (SADD-BA), spontaneous intracranial hypotension (SADD-SIH), or superficial siderosis (SADD-SS).

KDM1A genotyping and expression in 146 sporadic somatotroph pituitary adenomas.

IMPORTANCE: A paradoxical increase of growth hormone (GH) following oral glucose load has been described in ∼30% of patients with acromegaly and has been related to the ectopic expression of the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) in somatotropinomas. Recently, we identified germline pathogenic variants and somatic loss of heterozygosity of lysine demethylase 1A (KDM1A) in patients with GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. The ectopic expression of GIPR in both adrenal and pituitary lesions suggests a common molecular mechanism. OBJECTIVE: We aimed to analyze KDM1A gene sequence and KDM1A and GIPR expressions in somatotroph pituitary adenomas. SETTINGS: We conducted a cohort study at university hospitals in France and in Italy. We collected pituitary adenoma specimens from acromegalic patients who had undergone pituitary surgery. We performed targeted exome sequencing (gene panel analysis) and array-comparative genomic hybridization on somatic DNA derived from adenomas and performed droplet digital PCR on adenoma samples to quantify KDM1A and GIPR expressions. RESULTS: One hundred and forty-six patients with sporadic acromegaly were studied; 72.6% presented unsuppressed classical GH response, whereas 27.4% displayed a paradoxical rise in GH after oral glucose load. We did not identify any pathogenic variant in the KDM1A gene in the adenomas of these patients. However, we identified a recurrent 1p deletion encompassing the KDM1A locus in 29 adenomas and observed a higher prevalence of paradoxical GH rise (P = .0166), lower KDM1A expression (4.47 ± 2.49 vs 8.56 ± 5.62, P < .0001), and higher GIPR expression (1.09 ± 0.92 vs 0.43 ± 0.51, P = .0012) in adenomas from patients with KDM1A haploinsufficiency compared with those with 2 KDM1A copies. CONCLUSIONS AND RELEVANCE: Unlike in GIP-dependent primary bilateral macronodular adrenal hyperplasia, KDM1A genetic variations are not the cause of GIPR expression in somatotroph pituitary adenomas. Recurrent KDM1A haploinsufficiency, more frequently observed in GIPR-expressing adenomas, could be responsible for decreased KDM1A function resulting in transcriptional derepression on the GIPR locus.

Long-Term Outcomes after Incomplete Resection of Intramedullary Grade II Ependymomas: Is Adjuvant Radiotherapy Justified?

Ependymomas are the most common intramedullary tumors in adults. While gross total resection is the aim of surgery, tumor infiltration might limit resection. In cases of subtotal removal, the necessary adjuvant management remains unclear. The aim of our study was to assess the need for adjuvant radiotherapy after an incomplete resection of grade II intramedullary ependymomas (IME-II). We retrospectively reviewed all cases of IME-II operated upon at a single tertiary neurosurgical center from 2009 to 2018. Patients with anaplastic or myxopapillary ependymomas, and patients with a follow-up of less than three years, were excluded. We included 46 patients: 19 (41.3%) had a gross total resection; 21 (45.7%) had a subtotal resection; and 6 (13%) had a partial resection. None of the patients underwent adjuvant radiotherapy. Over a median follow-up of 79 months (range = 36-186), seven patients presented a radiological tumor progression with a mean delay of 50.9 months (range = 18-85), of which two were symptomatic (4.3%). Progression-free survival (PFS) was 90.1% at 5 years and 76.8% at 10 years. The extent of the resection was the only significant risk factor for secondary tumor progression (p = 0.012). Four of the seven patients with recurring IME-II were treated: three patients had a second surgery, leading to two GTR and one STR, followed by radiotherapy in one case, and one patient underwent radiotherapy alone. In this study, the rate of symptomatic progression and retreatment after incomplete resection of IME-II without adjuvant radiotherapy was low, suggesting a conservative approach in such cases.

Long-term outcome of surgical treatment for idiopathic spinal arachnoid web: A case series.

OBJECTIVE: Spinal arachnoid web (SAW) is a rare condition of the spine with limited long-term follow-up data in the literature. The longest reported follow-up period was an average 3.2 years. The objective of this study is to report our long-term results of patients who underwent surgical treatment for symptomatic idiopathic SAW. METHODS: We conducted a retrospective review of cases of idiopathic SAW that were operated between 2005-2020. We collected preoperative and last follow-up (LFU) data on motor force, sensory loss, pain, upper motor neuron (UMN) sign, gait disorder, sphincter dysfunction, syringomyelia, hyperintensity on T2-MRI, appearance of newer symptoms and number of reoperations. RESULTS: Our study included 9 patients with a mean follow-up period of 3.6years (range 2-9.1years). The surgical intervention involved a standard centered laminectomy, durotomy and arachnoid lysis. At presentation, motor weakness was present in 77.8% of patients, sensory loss in 66.7%, pain in 88.9%, sphincter dysfunction in 33.3%, UMN sign in 22%, gait disorder 55.6%, syringomyelia in 55.6% and MRI T2 hyperintensity in 55.6% of patients. At LFU, there was an improvement in all symptoms and signs to varying degrees. No new neurological symptoms appeared postoperatively, and there was no recurrence during the follow-up period. CONCLUSION: Our results demonstrate that the reported immediate and short-term favorable outcomes following arachnoid lysis for symptomatic SAW persist over a long-term period and the risk of readhesion-correlated neurological deterioration following conventional surgical intervention is low.

Surgical management of pituicytomas: a single-center case series.

OBJECTIVE: Pituicytomas (PT) are rare benign sellar and/or supra sellar tumors which surgical treatment might be challenging, owing to the hypervascularity of the tumor. Here, we report our experience with PTs, describe their clinical and radiological features, and propose an optimal therapeutic strategy. METHODS: This is a retrospective single-center study, reporting the clinical manifestations, radiological characteristics, histopathological features, treatment strategies and long-term outcomes of four patients who have been treated for a PT at Bicêtre University Hospital in Paris, France, over the past 7 years. RESULTS: Four patients were operated mean age at presentation was 60.25 years. Main symptoms, which tended to be progressive, included visual field defects and pituitary-hypothalamic dysfunction. Radiologically, all our cases resented with sellar and suprasellar localization with cavernous invasion in 75% of cases. Endoscopic transphenoidal approach was performed as first surgery for all cases. Transcranial route was done in one case. During surgery, important bleeding was observed in all cases. Gross total resection was obtained with a single surgery in two cases and a second surgery was necessary in the two remaining cases. Pathological diagnosis was confirmed in all cases. No recurrences were noted after an average follow-up of 3.6 years. CONCLUSIONS: PT is a rare differential diagnosis of sellar and/or parasellar tumors, whose hemorrhagic nature can become a challenge during surgery. We added four more cases to the literature to make physicians establish Piticytomas at suspicion diagnosis for sellar and/or suprasellar masses. Knowing the diagnosis, a preparation should be made preoperatively to avoid possible complications peroperatively.

Bevacizumab in real-life patients with recurrent glioblastoma: benefit or futility?

PURPOSE: Angiogenesis plays a key role in glioblastoma, but most anti-angiogenic therapy trials have failed to change the poor outcome of this disease. Despite this, and because bevacizumab is known to alleviate symptoms, it is used in daily practice. We aimed to assess the real-life benefit in terms of overall survival, time to treatment failure, objective response, and clinical benefit in patients with recurrent glioblastoma treated with bevacizumab. METHODS: This was a monocentric, retrospective study including patients treated between 2006 and 2016 in our institution. RESULTS: 202 patients were included. The median duration of bevacizumab treatment was 6 months. Median time to treatment failure was 6.8 months (95%CI 5.3-8.2) and median overall survival was 23.7 months (95%CI 20.6-26.8). Fifty percent of patients had a radiological response at first MRI evaluation, and 56% experienced symptom amelioration. Grade 1/2 hypertension (n = 34, 17%) and grade one proteinuria (n = 20, 10%) were the most common side effects. CONCLUSIONS: This study reports a clinical benefit and an acceptable toxicity profile in patients with recurrent glioblastoma treated with bevacizumab. As the panel of therapies is still very limited for these tumors, this work supports the use of bevacizumab as a therapeutic option.

Magendie's foramen debridement and catheterisation for the treatment of syringomyelia due to diffuse craniocervical junction arachnoiditis. A case report and technical note.

A 36 year old woman was referred to our department for symptomatic lumbar spinal arachnoiditis following an epidural anaesthesia for childbirth. She did not had other known causative factor and she was free of any neurological symptoms before. She rapidly developed lower limbs impairment by compressing intradural lumbar collections and arachnoiditis requiring surgical decompression and subsequently internal cerebrospinal fluid shunting for acute hydrocephalus. Three years and the half later, she developed a severe tetraparesis due to a massive syrinx consecutive to the fourth ventricle outlets obstruction cause by the ongoing diffuse craniocervical junction arachnoiditis. Our aim was to treat all the problems in one step. An open fourth ventriculostomy of the Magendie's foramen with catheter insertion from the fourth ventricle down to the upper cervical subarachnoid space improve both the patient status and imagery.

Surgical Management after Chiari Decompression Failure: Craniovertebral Junction Revision versus Shunting Strategies.

Revision surgery after posterior fossa decompression for Chiari malformation is not uncommon and poses both strategic and technical challenges. We conducted a single-center retrospective cohort study including all adult patients who underwent revision surgery after posterior fossa decompression for Chiari type I malformation between 2010 and 2019. Among 311 consecutive patients operated on for Chiari malformation at our institution, 35 patients had a least one revision surgery with a mean follow-up of 70.2 months. Mean delay for revision was 28.8 months. First revision surgery was performed at the level of the foramen magnum in 25/35 cases and consisted in duraplasty revision in all cases, arachnolysis (51.4%), additional bone decompression (37.1%), tonsillar coagulation or resection (25.7%), 4th ventricle to cervical subarachnoid spaces shunt (5.7%). Most repeat revisions consisted in CSF diversion procedures, with either ventriculo-peritoneal or syringo-peritoneal shunts. Mean number of interventions per patient was 3.2, with 22.9% of patients undergoing 4 or more surgeries. Based on our experience, we propose that revision at the level of the foramen magnum should be considered as a first-line strategy for Chiari decompression failure. Shunting procedures can be performed in case of extensive arachnoiditis or repeated failures.