Neurosurgery Blog

Icon

Daily bibliographic review of the Neurosurgery Department. La Fe University Hospital. Valencia, Spain

Surgical Treatment of Chiari I Malformation

Neurosurgery 71:365–380, 2012 DOI: 10.1227/NEU.0b013e31825c3426

Foramen magnum decompression is widely accepted as the treatment of choice for Chiari I malformation. However, important surgical details of the procedure are controversial.

OBJECTIVE: This study analyzes 371 decompressions focusing on intraoperative findings, analysis of complications, and long-term outcomes.

METHODS: Among 644 patients between 1985 and 2010, 359 patients underwent 371 decompressions. Surgery for symptomatic patients consisted of suboccipital craniectomy, C1 laminectomy, arachnoid dissection, and duraplasty. Short-term results were determined after 3 months; long-term outcomes were evaluated with Kaplan-Meier statistics.

RESULTS: The mean age was 40 ± 16 years; mean follow-up was 49 ± 56 months; 75.8% demonstrated syringomyelia. The complication rate was 21.8% with permanent surgical morbidity of 3.2% and surgical mortality of 1.3%. Of the patients, 73.6% reported improvement after 3 months; 21% were unchanged. Overall, 14.3% demonstrated a neurological deterioration within 5 years and 15.4% within 10 years. The severity of neurological symptoms correlated with the grade of arachnoid pathology. Outcome data correlated with the number of previous decompressions, severity of arachnoid pathology, handling of the arachnoid, type of duraplasty, and surgical experience. Firsttime decompressions with arachnoid dissection and an alloplastic duraplasty resulted in surgical morbidity for 2.0%, a 0.9% mortality rate, postoperative improvement after 3 months for 82%, and neurological recurrence rates of 7% after 5 years and 8.7% after 10 years.

CONCLUSION: Arachnoid pathology in Chiari I malformation has an impact on clinical symptoms and postoperative results. Decompressions with arachnoid dissection and an alloplastic duraplasty performed by surgeons experienced with this pathology offer a favorable long-term prognosis.

Volumetric analysis of syringomyelia following hindbrain decompression for Chiari malformation Type I: syringomyelia resolution follows exponential kinetics

Neurosurg Focus 31 (3):E4, 2011. DOI: 10.3171/2011.6.FOCUS11106

Resolution of syringomyelia is common following hindbrain decompression for Chiari malformation, yet little is known about the kinetics governing this process. The authors sought to establish the volumetric rate of syringomyelia resolution.

Methods. A retrospective cohort of patients undergoing hindbrain decompression for a Chiari malformation Type I with preoperative cervical or thoracic syringomyelia was identified. Patients were included in the study if they had at least 3 neuroimaging studies that detailed the entirety of their preoperative syringomyelia over a minimum of 6 months postoperatively. The authors reconstructed the MR images in 3 dimensions and calculated the volume of the syringomyelia. They plotted the syringomyelia volume over time and constructed regression models using the method of least squares. The Akaike information criterion and Bayesian information criterion were used to calculate the relative goodness of fit. The coefficients of determination R2 (unadjusted and adjusted) were calculated to describe the proportion of variability in each individual data set accounted for by the statistical model.

Results. Two patients were identified as meeting inclusion criteria. Plots of the least-squares best fit were identified as 4.01459e-0.0180804x and 13.2556e-0.00615859x. Decay of the syringomyelia followed an exponential model in both patients (R2 = 0.989582 and 0.948864).

Conclusions. Three-dimensional analysis of syringomyelia resolution over time enables the kinetics to be estimated. This technique is yet to be validated in a large cohort. Because syringomyelia is the final common pathway for a number of different pathological processes, it is possible that this exponential only applies to syringomyelia related to treatment of Chiari malformation Type I.

Pathogenesis of syringomyelia associated with Chiari type 1 malformation: review of evidences and proposal of a new hypothesis

Neurosurg Rev (2010) 33:271–285. DOI 10.1007/s10143-010-0266-5

The exact pathogenesis of syringomyelia associated with Chiari type 1 malformation is unknown, although a number of authors have reported their theories of syrinx formation. The purpose of this review is to understand evidences based on the known theories and to create a new hypothesis of the pathogenesis. We critically review the literatures on clinicopathological, radiological, and clinical features of this disorder.

The previously proposed theories mainly focused on the driven mechanisms of the cerebrospinal fluid (CSF) into the spinal cord. They did not fully explain radiological features or effects of surgical treatment such as shunting procedures.

Common findings of the syrinx in clinicopathological studies were the communication with the central canal and extracanalicular extension to the posterior gray matter. Most of the magnetic resonance imaging studies demonstrated blockade and alternated CSF dynamics at the foramen magnum, but failed to show direct communication of the syrinx with the CSF spaces.

Pressure studies revealed almost identical intrasyrinx pressure to the subarachnoid space and decreased compliance of the spinal CSF space.

Recent imaging studies suggest that the extracellular fluid accumulation may play an important role. The review of evidences promotes a new hypothesis of syrinx formation. Decreased absorption mechanisms of the extracellular fluid may underlie the pathogenesis of syringomyelia. Reduced compliance of the posterior spinal veins associated with the decreased compliance of the spinal subarachnoid space will result in disturbed absorption of the extracellular fluid through the intramedullary venous channels and formation of syringomyelia.

Neurosurgery Department. “La Fe” University Hospital. Valencia, Spain

Archives

Amazon Shop

The Safety and Feasibility of Image-Guided BrainPath-Mediated Trans-Sulcal Hematoma Evacuation

Haptic Virtual Reality Aneurysm Clipping

Subtemporal Approach for AICA Aneurysm Clipping

MCA Aneurysm Anatomical Classification Scheme

Blister Aneurysms of the Internal Carotid Artery

Bypass for Complex Basilar Aneurysms

Basilar Invagination and Atlanto-Axial Dislocation Video 1

Indocyanine Green Videoangiography “In Negative” Video 2

Indocyanine Green Videoangiography “In Negative” Video 1

Management of a Recurrent Coiled Giant Posterior Cerebral Artery Aneurysm

Bypass for Complex Basilar Aneurysms

Expanded Endonasal Approach for 2012 MERC

Endoscopic Endonasal Middle Clinoidectomy Video 1

Endoscopic Endonasal Middle Clinoidectomy Video 2

Neurosurgery CNS: Flash Fluorescence for MCA Bypass Video 2

Neurosurgery CNS: Flash Fluorescence for MCA Bypass Video 1

Neurosurgery CNS: Endoscopic Transventricular Lamina Terminalis Fenestration Video 2

Neurosurgery CNS: Endoscopic Transventricular Lamina Terminalis Fenestration Video 1

Neurosurgery CNS: Surgery for Giant PCOM Aneurysms Video 2

Neurosurgery CNS: Surgery for Giant PCOM Aneurysms Video 1

NeurosurgeryCNS: Endovascular-Surgical Approach to Cavernous dAVF

Neurosurgery CNS: Lateral Supraorbital Approach Applied to Anterior Clinoidal Meningiomas Video 4

Neurosurgery CNS: Lateral Supraorbital Approach Applied to Anterior Clinoidal Meningiomas Video 3

Neurosurgery CNS: Lateral Supraorbital Approach Applied to Anterior Clinoidal Meningiomas Video 2

Neurosurgery CNS: Lateral Supraorbital Approach Applied to Anterior Clinoidal Meningiomas Video 1

NeurosurgeryCNS: Surgery of AVMs in Motor Areas

NeurosurgeryCNS: The Fenestrated Yaşargil T-Bar Clip

NeurosurgeryCNS: Cotton-Clipping Technique to Repair Intraoperative Aneurysm Neck Tear Video 3

NeurosurgeryCNS: Cotton-Clipping Technique to Repair Intraoperative Aneurysm Neck Tear Video 2

NeurosurgeryCNS: Cotton-Clipping Technique to Repair Intraoperative Aneurysm Neck Tear Video 1

NeurosurgeryCNS. ‘Double-Stick Tape’ Technique for Offending Vessel Transposition in Microvascular Decompression

NeurosurgeryCNS: Advances in the Treatment and Outcome of Brain Stem Cavernous Malformation Surgery: 300 Patients

3T MRI Integrated Neuro Suite

NeurosurgeryCNS: 3D In Vivo Modeling of Vestibular Schwannomas and Surrounding Cranial Nerves Using DIT

NeurosurgeryCNS: Microsurgery for Previously Coiled Aneurysms: Experience on 81 Patients: Video 7

NeurosurgeryCNS: Microsurgery for Previously Coiled Aneurysms: Experience on 81 Patients: Video 6

NeurosurgeryCNS: Microsurgery for Previously Coiled Aneurysms: Experience on 81 Patients: Video 5

NeurosurgeryCNS: Microsurgery for Previously Coiled Aneurysms: Experience on 81 Patients: Video 4

NeurosurgeryCNS: Microsurgery for Previously Coiled Aneurysms: Experience on 81 Patients: Video 3

NeurosurgeryCNS: Microsurgery for Previously Coiled Aneurysms: Experience on 81 Patients: Video 2

NeurosurgeryCNS: Microsurgery for Previously Coiled Aneurysms: Experience on 81 Patients: Video 1

NeurosurgeryCNS: Corticotomy Closure Avoids Subdural Collections After Hemispherotomy

NeurosurgeryCNS: Operative Nuances of Side-to-Side in Situ PICA-PICA Bypass Procedure

NeurosurgeryCNS. Waterjet Dissection in Neurosurgery: An Update After 208 Procedures: Video 3

NeurosurgeryCNS. Waterjet Dissection in Neurosurgery: An Update After 208 Procedures: Video 2

NeurosurgeryCNS. Waterjet Dissection in Neurosurgery: An Update After 208 Procedures: Video 1

NeurosurgeryCNS: Fusiform Aneurysms of the Anterior Communicating Artery

NeurosurgeryCNS. Initial Clinical Experience with a High Definition Exoscope System for Microneurosurgery

NeurosurgeryCNS: Endoscopic Treatment of Arachnoid Cysts Video 2

NeurosurgeryCNS: Endoscopic Treatment of Arachnoid Cysts Video 1

NeurosurgeryCNS: Typical colloid cyst at the foramen of Monro.

NeurosurgeryCNS: Neuronavigation for Neuroendoscopic Surgery

NeurosurgeryCNS:New Aneurysm Clip System for Particularly Complex Aneurysm Surgery

NeurosurgeryCNS: AICA/PICA Anatomical Variants Penetrating the Subarcuate Fossa Dura

Craniopharyngioma Supra-Orbital Removal

NeurosurgeryCNS: Use of Flexible Hollow-Core CO2 Laser in Microsurgical Resection of CNS Lesions

NeurosurgeryCNS: Ulnar Nerve Decompression

NeurosurgeryCNS: Microvascular decompression for hemifacial spasm

NeurosurgeryCNS: ICG Videoangiography

NeurosurgeryCNS: Inappropiate aneurysm clip applications


32,788
Unique
Visitors
Powered By Google Analytics

Total views

  • 0
%d bloggers like this: