Decompression Procedures Research Articles

CORR Insights®: A Small Number of Surgeons Perform the Large Majority of Uncommon Nerve Decompression Procedures.

CORR Insights®: A Small Number of Surgeons Perform the Large Majority of Uncommon Nerve Decompression Procedures.

Clinical Features of Conduction Block in Ulnar Neuropathy at the Elbow: The Surgery of the Ulnar Nerve (SUN) Multicenter Clinical Trial

Background: In ulnar neuropathy at the elbow, weakness is classically a sign of severe disease. Weakness is associated with motor axonal loss as measured by decreased distal compound muscle action potential (CMAP) amplitude. Conduction block, a demyelinating phenomenon that recovers readily, can also cause weakness, creating ambiguity for the treating clinician. Methods: This cross-sectional study evaluated baseline blinded data collected from 2020-2023 from the Surgery of the Ulnar Nerve randomized controlled trial comparing in-situ decompression versus transposition procedures. Adult patients underwent electrodiagnostic testing, clinical motor and sensory testing, and completed the Michigan Hand Questionnaire and Carpal Tunnel Questionnaire. Results: 177 patients were categorized into 3 distinct groups based on normal distal CMAP amplitudes (77 patients), presence of conduction block with or without distal CMAP amplitude loss (37 patients), or pure axonal loss with distal CMAP amplitude loss in the absence of conduction block (63 patients). Compared to the normal group, patients with conduction block had significantly decreased pinch strength and worse function domain scores on the Michigan Hand Questionnaire and Carpal Tunnel Questionnaire, but shorter duration of disease. Patients with pure axonal loss had decreased pinch strength, worse 2-point discrimination, and worse overall, function and aesthetics domain scores on the Michigan Hand Questionnaire. There was a significant interaction between the effects of conduction block and distal CMAP amplitude on pinch strength, indicating that higher degrees of conduction block resulted in more pronounced loss of pinch strength in patients with relatively preserved distal CMAP amplitude. Conclusions: Our findings support the paradigm that ulnar neuropathy at the elbow presenting with conduction block represents a distinct and intermediate pathophysiology, distinguished by quicker onset with less advanced neurological deficits. Level of evidence: Prognostic Level II

Enteric Tube Placement and Management: Tips for Interventional Radiologists

AbstractThere is a significant risk of malnutrition and aspiration among hospitalized patients, particularly the elderly, patients with head and neck malignancy, and those with a chronic debilitating disease. Enteral feeding is preferred over parenteral feeding for patients with functional gastrointestinal tracts but who have impaired swallowing due to its cost-effectiveness, lesser complications, and theoretical benefits such as preserving mucosal architecture and gut-associated lymphoid tissue. While nasogastric and nasojejunal tubes address short-term feeding needs, long-term enteral feeding tubes are crucial for patients requiring nutritional support beyond 4 weeks. Enteric tube placement can be performed surgically, endoscopically, or radiologically, with radiologically inserted gastrostomy emerging as a safe and effective method. This review article discusses various interventional radiological techniques for enteral feeding, including percutaneous gastrostomy, gastrojejunostomy, jejunostomy tube placement, and gastrointestinal tract decompression procedures like cecostomy. It covers procedural considerations, patient selection criteria, technical aspects, and outcomes, drawing on current evidence and clinical experience. The review also addresses emerging trends, advancements, and future directions in interventional radiology for enteral feeding and gastrointestinal tract decompression, aiming to contribute to the ongoing evolution of clinical practice and patient care. Key recommendations from international guidelines are summarized, emphasizing individualized risk assessment for optimal enteral feeding strategies.

Same-day discharge following lumbar spine neural decompression

IntroductionThe concept of same-day discharge following lumbar spine surgery for neural elements decompression, introduced in the 1980 s, represents a significant paradigm shift in postoperative care, offering potential benefits in terms of efficiency, convenience, and cost-effectiveness. However, concerns regarding patient safety and complications have persisted. This study aims to assess same-day discharge rates following lumbar spine decompression surgery, identify preoperative predictors, and compare outcomes between same-day discharge and hospitalization. MethodsA retrospective comparative analysis was conducted using data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Participant Use File spanning 2016 to 2021. A total of 58,430 patients undergoing lumbar spine decompression procedures were included. Statistical analysis was performed using SPSS software, with significance determined at p < 0.05. ResultsSignificant differences were observed in preoperative factors, operative variables, and postoperative outcomes between patients discharged on the same day and those hospitalized. Preoperative comorbidities, operative time, length of stay, utilization of minimally invasive approaches, and 30-day mortality rates differed significantly between the two groups. Notably, same-day discharge demonstrated superior outcomes, with lower rates of unplanned intubation, readmission, and reoperation compared to hospitalization. ConclusionIn conclusion, same-day discharge following lumbar spine decompression procedures holds promise as a safe and effective practice, offering advantages in terms of patient outcomes and healthcare resource utilization. Further research and implementation of standardized protocols are warranted to maximize the benefits of same-day discharge while ensuring patient safety and satisfaction.

Identifying Factors for Predicting Postoperative Segmental Motor Paralysis in Patients Undergoing Anterior Cervical Spine Surgery: A Multicenter Study.

Retrospective cohort study. To investigate the incidence of and risk factors for segmental motor paralysis after anterior cervical spine surgery. Segmental motor paralysis is a potential complication following both anterior and posterior cervical decompression procedures; however, previous studies investigating risk factors for segmental motor paralysis after anterior cervical spine surgery were limited by small sample sizes. Consequently, the exact pathogenesis and risk factors for this complication remain poorly understood, highlighting the need for larger-scale investigations focused exclusively on anterior cervical spine surgeries. We retrospectively reviewed the clinico-demographic and operative factors and postoperative outcomes of 1,428 patients undergoing anterior cervical spine surgery at three spine centers in Japan. Postoperative segmental motor paralysis was defined as deterioration of upper extremity muscle strength by ≥1 grade; recovery was defined as a return to preoperative muscle strength levels. Univariate and multivariate analyses were performed to identify risk factors. Ninety-nine patients (6.9%) developed segmental motor paralysis, mostly involving the C5 segment (81.8%), the incidence being highest in patients with ossification of the posterior longitudinal ligament (OPLL) and those undergoing anterior cervical corpectomy and fusion or hybrid fusion (discectomy + corpectomy). Older age, male sex, higher body mass index, OPLL, and cervical corpectomy were independent risk factors for paralysis, with these patients having significantly worse clinical outcomes at 1 year postoperatively. Most patients (74/99, 79.6%) regained preoperative muscle strength levels an final follow up. This study identified important clinico-demographic and operative risk factors for segmental motor paralysis after anterior cervical spine surgery. Patients undergoing corpectomy, with or without OPLL, were found to be at particularly high risk. While most patients recover well, worse outcomes with segmental motor paralysis highlight the importance of preventing this complication, particularly for OPLL patients and corpectomy procedures. III.

Finite element analysis shows minimal stability difference between individualized mini-hemilaminectomy-corpectomy and partial lateral corpectomy in a dog model.

Use finite element analysis to evaluate the biomechanical effects of spinal decompression procedures in healthy Beagle dogs, comparing individualized mini-hemilaminectomy-corpectomy (iMHC), mini-hemilaminectomy, partial lateral corpectomy (PLC), and hemilaminectomy. A finite element model of the L1-L2 functional spinal unit was generated using CT data. For each decompression model, loads were applied in 0.2-Nm steps (maximum, 2.0 Nm) in 6 directions: flexion, extension, right and left lateral bending, and right and left axial rotation. The L1 spinous process tip displacement angle was quantified numerically. Among the 4 techniques, mini-hemilaminectomy exhibited the smallest displacement angles across all directions. Hemilaminectomy exhibited the largest displacement angles in extension, flexion, right rotation, and left rotation across all techniques. Left and right lateral bending displacement angles were marginally larger for iMHC than for hemilaminectomy at 0.4 Nm; however, at 2.0 Nm, displacement angles were similar. Mini-hemilaminectomy minimizes functional spinal unit instability to the greatest extent. Hemilaminectomy is more unstable than iMHC and PLC in flexion, extension, and rotation. Mini-hemilaminectomy-corpectomy and PLC are more unstable than hemilaminectomy in lateral bending, with iMHC being slightly more unstable than PLC or nearly equal. Mini-hemilaminectomy minimizes instability to the greatest extent in cases of ventrolateral spinal compression. In cases of ventral spinal compression, iMHC may be preferable to PLC for providing equivalent stability without impeding spinal cord visualization, but both techniques can cause instability depending on loading direction, so careful attention to postoperative instability is necessary when excessive vertebral body resection is involved.

Current research status and prospects for clinical application of robotics in spinal surgery

With the rapid advancement of artificial intelligence and the increasing integration of medical engineering, robot-assisted (RA) technology in spinal surgery has made significant strides, with its clinical application range continuously expanding. This article provides a comprehensive review of relevant literature on spinal surgery robots over the past decade, summarizing recent advancements in screw placement techniques such as cervical, thoracic, and lumbar pedicle screws; cortical bone trajectory (CBT) screws; cervical lateral mass screws; and S2 sacroiliac (S2AI) screws. It also discusses RA-guided targeted puncture and endoscope placement through intervertebral foramen as well as decompressive laminectomy procedures. Furthermore, this article systematically analyzes the advantages and disadvantages of RA technology while elucidating its accuracy, safety, and practicality. We believe that this article will help clinicians to gain a deeper understanding of the current clinical application status of spinal surgery robots while promoting further enhancements and wider adoption of RA technology to ultimately benefit more patients.

The impact of smoking on patient-reported outcomes following lumbar decompression: an analysis of the Quality Outcomes Database.

Smoking has been shown to negatively impact spinal health, as well as the outcomes of spinal fusion. Published reports show conflicting data regarding whether smoking negatively impacts patient outcomes following lumbar decompression. The objective of this study was to investigate whether smoking affects the outcomes of patients undergoing lumbar decompression for spinal stenosis or herniated disc. The Quality Outcomes Database was queried for patients with spinal stenosis or lumbar disc herniation who underwent one- or two-level lumbar decompression without fusion. All patients had preoperative and 12-month outcome measures and were divided into groups of nonsmokers and current smokers. Outcomes were compared between the two groups, as well as the percentage of patients reaching the minimal clinically important difference (MCID) threshold for numeric rating scale (NRS) back and leg pain scores and the Oswestry Disability Index (ODI). Of 17,271 patients, 14,233 were nonsmokers and 3038 were current smokers. Smokers had worse baseline NRS back and leg pain, ODI, and EQ-5D scores and experienced slightly less improvement in all measures following lumbar decompression (p ≤ 0.009), although changes were largely similar, and a high percentage of patients achieved the MCID thresholds for NRS back pain (78% nonsmokers vs 75% smokers), NRS leg pain (79% nonsmokers vs 73% smokers), and ODI (74% nonsmokers vs 68% smokers). Comparison of propensity-matched cohorts did not identify any difference in outcomes in smokers versus nonsmokers. In patients undergoing lumbar decompression for spinal stenosis or herniated disc, smokers demonstrated slightly less improvement in outcomes compared with nonsmokers, and a high proportion of both groups achieved meaningful improvement with surgery. While smoking cessation should be strongly encouraged in all patients, lumbar decompression procedures for spinal stenosis and herniated disc should not be denied to smokers.

Spinal cord compression by cystic IgG4-related spinal pachymeningitis mimicking neurocysticercosis: a case report

BackgroundTo report a case of IgG4-related pachymeningitis presenting with cystic lesions mimicking neurocysticercosis.Case presentationA 40-year-old female patient with tetraparesis, dysphagia and dysphonia was evaluated with clinical examination, magnetic resonance imaging, and meningeal biopsy. Magnetic resonance imaging (MRI) revealed diffuse pachymeningeal enhancement involving the cranial, cervical, thoracic, and lumbar segments with spinal cord compression and cystic lesions. CSF immunology was initially positive for cysticercus cellulosae. After disease progression a meningeal biopsy was compatible with IgG4 related disease. The patient had partial response to rituximab and needed multiple surgical procedures for spinal cord decompression and CSF shunting.ConclusionsThis case highlights the possibility of IgG4-related disease in patients with diffuse pachymeningitis causing spinal cord compression, even with cystic lesions on MRI. Diagnosis of IgG4-related pachymeningitis is paramount due to the possibility of treatment response to immunotherapy, particularly to anti-CD20 agents.

Endoscope-Assisted Revision Surgery after Lumbar Fusion with Pedicle Screw Fixation: A Case Series and Literature Review.

Lumbar internal fixation and fusion can be subject to failure requiring revision surgery. Endoscopic revision surgery with minimal invasiveness may be a helpful therapeutic intervention in the management of certain fusion-related complications. According to the author's knowledge, there are few references to this technique in English literature. This study aimed to investigate the efficacy of endoscope-assisted revision surgery in patients with recurrent radiculopathy after lumbar fusion surgery, discuss the necessity of revision surgery, and review the relevant literature. We report a case series and review relevant literature. Information was gathered from the electronic medical record in our hospital. A total of 231 patients who underwent endoscopic spine procedures from January 2021 to October 2022 were reviewed. Three patients who underwent endoscopic decompressive procedures after lumbar fusion surgeries at a correspondence segment were identified, and the clinical courses and radiological findings of these patients were retrospectively reviewed. The average interval from initial to revision surgery was 30.74 (range 10.50-48.00) months. The patients include one man and two women with an average age of 75.67 (range 68-81) years at the initial operation. Three patients developed symptoms of recurrent myelopathy after their initial surgery due to canal stenosis in the fusion segment and hyperostosis. All patients experienced symptom relief after revision surgery. At a mean follow-up time of 0.96 months, endoscopic decompression resulted in the average numerical rating scale (NRS) score for lower limb pain on the symptomatic side being reduced by 2.67. Patients rated their leg pain on average as 4.5 ± 0.5. Endoscope-assisted revision surgery after lumbar fusion with pedicle screw fixation is a promising therapeutic strategy in treating recurrent radiculopathy. Spinal stenosis and hyperostosis are two of the most significant reasons for revision surgery. Resection of intraspinal lesions and endoscopic foraminal decompression appear to have promising outcomes. Certain fusion-related complications may be effectively treated with endoscope-assisted revision surgery. Further research should be conducted to investigate the clinical efficacy of revision surgery.

Not Every Size Fits All: Surgical Corridors for Clival and Cervical Chordomas-A Systematic Review of the Literature and Illustrative Cases.

Introduction. Clival chordomas represent a rare but clinically significant subset of skull base tumors, characterized by a locally aggressive nature and a location in proximity to vital neurovascular structures. Surgical resection, often combined with adjuvant therapies, remains the cornerstone of clival chordoma treatment, and various approaches and techniques have evolved to maximize tumor removal while preserving neurological function. Recent advancements in skull base surgery, imaging, and adjuvant therapies have improved outcomes by reducing morbidity and thus enhancing long-term survival. Methods and Results. We have conducted a systematic review on PubMed/Medline following PRISMA guidelines regarding indications, the extent of resection (EOR), and complication rates. Then, we present three illustrative cases from our personal experience, which started 25 years ago with CVJ instrumentation procedures and 15 years ago with anterior decompressive transmucosal procedures performed with the aid of an operative microscope, an endoscope, and neuroradiological monitoring. Conclusions. Traditionally, the transoral approach (TOA) is the most frequently used corridor for accessing the lower clivus and the anterior craniovertebral junction (CVJ), without the need to mobilize or retract neural structures; however, it is associated with a high rate of complications. The endonasal approach (EEA) provides access to the anterior CVJ as well as to the lower, middle, and superior clivus, decreasing airway and swallowing morbidity, preserving palatal function, decreasing postoperative pain, and reducing the incidence of tracheostomy. The submandibular retropharyngeal approach (SRA) allows unique access to certain cervical chordomas, which is better suited when the lesion is located below the clivus and in the midline.

Acute cholangitis: a state-of-the-art review.

Acute cholangitis is a potentially life-threatening bacterial infection of the intra and/or extrahepatic bile ducts. It remains the second and third cause of community-acquired and hospital-acquired bacteremia, respectively, and is associated with mortality rates of up to 15%, despite advances in broad-spectrum antimicrobial therapy and improved access to emergency biliary tract decompression procedures. Even though not much has changed in recent years in terms of diagnosis or treatment, new data have emerged regarding multidrug-resistant bacteria that serve as etiologic agents of cholangitis. Moreover, different approaches in antibiotic regimes depending on severity grading and bile sample cultures as well as novel minimally invasive endoscopic procedures that can help when consecrated treatments such as endoscopic retrograde cholangiopancreatography (ERCP) fail, cannot be performed, or are unavailable have been proposed. This state-of-the-art review aims to offer a complete and updated assessment of the epidemiology, novel diagnostic and therapeutic methods, complications, and prognostic variables of acute cholangitis. The authors will review the prognostic implications of unusual complications, the relevance of regular bile samples and antibiograms, and their new role in guiding antibiotic therapy and limiting antibiotic resistance to present an organized and comprehensive approach to the care of acute cholangitis.

Preoperative Radiographic Predictors of Subsequent Fusion After Lumbar Decompression Surgery.

Retrospective cohort study. The purpose of this study is to determine which demographic, surgical, and radiographic preoperative characteristics are most associated with the need for subsequent fusion after decompression lumbar spinal surgery. There is a relatively high rate of the need for repeat decompression or fusion after an index decompression procedure for degenerative spine disease. Nevertheless, there is a dearth of literature identifying risk factors for lumbar fusion following decompression surgery. Patients 18 years or older receiving a primary lumbar decompression surgery within the levels of L3-S1 between 2011 and 2020 were identified. All patients had preoperative radiographs and 2 years of follow-up data. Chart review was performed for surgical characteristics and demographics. The sagittal parameters included lumbar lordosis (LL), segmental lordosis (SL), anterior disk height (aDH), posterior disk height (pDH), sacral slope (SS), and pelvic tilt (PT). Pelvic incidence (PI=PT+SS) and pelvic incidence minus lumbar lordosis (PI-LL) were calculated. In addition, the Roussouly classification was determined for each patient. Bivariant and multivariant analyses were performed. Of the 363 patients identified in this study, 96 patients had a fusion after their index decompression surgery. Multivariable analysis identified involvement of L4-L5 level in the decompression [odds ratio (OR)=1.83 (1.09-3.14), P =0.026], increased L5-S1 segmental lordosis [OR=1.08 (1.03-1.13), P =0.001], decreased SS [OR=0.96 (0.93-0.99), P =0.023], and decreased endplate obliquity [OR=0.88 (0.77-0.99), P =0.040] as significant independent predictors of fusion after decompression surgery. This is one of the first studies to assess preoperative sagittal parameters in conjunction with demographic variables to determine predictors of the need for fusion after index decompression. We demonstrated that decompression at L4-L5, greater L5-S1 segmental lordosis, decreased sacral slope, and decreased endplate obliquity were associated with higher rates of fusion after decompression surgery.

Biomimetic Porous Ti6Al4V Implants: A Novel Interbody Fusion Cage via Gel-Casting Technique to Promote Spine Fusion.

An interbody fusion cage (Cage) is crucial in spinal decompression and fusion procedures for restoring normal vertebral curvature and rebuilding spinal stability. Currently, these Cages suffer from issues related to mismatched elastic modulus and insufficient bone integration capability. Therefore, a gel-casting technique is utilized to fabricate a biomimetic porous titanium alloy material from Ti6Al4V powder. The biomimetic porous Ti6Al4V is compared with polyetheretherketone (PEEK) and 3D-printed Ti6Al4V materials and their respective Cages. Systematic validation is performed through mechanical testing, in vitro cell, in vivo rabbit bone defect implantation, and ovine anterior cervical discectomy and fusion experiments to evaluate the mechanical and biological performance of the materials. Although all three materials demonstrate good biocompatibility and osseointegration properties, the biomimetic porous Ti6Al4V, with its excellent mechanical properties and a structure closely resembling bone trabecular tissue, exhibited superior bone ingrowth and osseointegration performance. Compared to the PEEK and 3D-printed Ti6Al4V Cages, the biomimetic porous Ti6Al4V Cage outperforms in terms of intervertebral fusion performance, achieving excellent intervertebral fusion without the need for bone grafting, thereby enhancing cervical vertebra stability. This biomimetic porous Ti6Al4V Cage offers cost-effectiveness, presenting significant potential for clinical applications in spinal surgery.

Effect of two-level decompressive procedures on the biomechanics of the lumbo-sacral spine: an ex vivo study.

Hemilaminectomy and laminectomy are decompressive procedures commonly used in case of lumbar spinal stenosis, which involve the removal of the posterior elements of the spine. These procedures may compromise the stability of the spine segment and create critical strains in the intervertebral discs. Thus, this study aimed to investigate if decompressive procedures could alter the biomechanics of the lumbar spine. The focus was on the changes in the range of motion and strain distribution of the discs after two-level hemilaminectomy and laminectomy. Twelve L2-S1 cadaver specimens were prepared and mechanically tested in flexion, extension and both left and right lateral bending, in the intact condition, after a two-level hemilaminectomy on L4 and L5 vertebrae, and a full laminectomy. The range of motion (ROM) of the entire segment was assessed in all the conditions and loading configurations. In addition, Digital Image Correlation was used to measure the strain distribution on the surface of each specimen during the mechanical tests, focusing on the disc between the two decompressed vertebrae and in the two adjacent discs. Hemilaminectomy did not significantly affect the ROM, nor the strain on the discs. Laminectomy significantly increased the ROM in flexion, compared to the intact state. Laminectomy significantly increased the tensile strains on both L3-L4 and L4-L5 disc (p = 0.028 and p = 0.014) in ipsilateral bending, and the compressive strains on L4-L5 intervertebral disc, in both ipsilateral and contralateral bending (p = 0.014 and p = 0.0066), with respect to the intact condition. In conclusion, this study found out that hemilaminectomy did not significantly impact the biomechanics of the lumbar spine. Conversely, after the full laminectomy, flexion significantly increased the range of motion and lateral bending was the most critical configuration for largest principal strain.

A Small Number of Surgeons Perform the Large Majority of Uncommon Nerve Decompression Procedures.

A Small Number of Surgeons Perform the Large Majority of Uncommon Nerve Decompression Procedures.

Decompressive craniectomy to cranioplasty: a retrospective observational study using Hospital Episode Statistics in England

ObjectivesTo investigate the longitudinal trends of decompressive craniectomy (DC) following traumatic brain injury (TBI) or stroke and explore whether the timing of cranial reconstruction affected revision or removal rates using...

Trigeminal neuralgia.

Trigeminal neuralgia (TN) is a facial pain disorder characterized by intense and paroxysmal pain that profoundly affects quality of life and presents complex challenges in diagnosis and treatment. TN can be categorized as classical, secondary and idiopathic. Epidemiological studies show variable incidence rates and an increased prevalence in women and in the elderly, with familial cases suggesting genetic factors. The pathophysiology of TN is multifactorial and involves genetic predisposition, anatomical changes, and neurophysiological factors, leading to hyperexcitable neuronal states, central sensitization and widespread neural plasticity changes. Neurovascular compression of the trigeminal root, which undergoes major morphological changes, and focal demyelination of primary trigeminal afferents are key aetiological factors in TN. Structural and functional brain imaging studies in patients with TN demonstrated abnormalities in brain regions responsible for pain modulation and emotional processing of pain. Treatment of TN involves a multifaceted approach that considers patient-specific factors, including the type of TN, with initial pharmacotherapy followed by surgical options if necessary. First-line pharmacological treatments include carbamazepine and oxcarbazepine. Surgical interventions, including microvascular decompression and percutaneous neuroablative procedures, can be considered at an early stage if pharmacotherapy is not sufficient for pain control or has intolerable adverse effects or contraindications.

Prevalence of Anterior Inferior Cerebellar Artery Vascular Loop in Cerebellopontine Angle With Three-Dimensional Constructive Interference in Steady State (CISS) Sequence MRI.

Background The cerebellopontine angle (CPA) cistern houses vital neurovascular structures such as cranial nerves V, VII, and VIII and the anterior inferior cerebellar artery (AICA), often leading to neurovascular compression syndromes due to its complex anatomy. Although vascular compression is a recognized cause of certain neuralgias, its association with otologic symptoms such as tinnitus, hearing loss, and dizziness remains uncertain. Hence, this study aims to determine the prevalence of the AICA vascular loop in the CPA cistern on MRI in patients with asymptomatic audiovestibular symptoms. Methodology Adult patients who underwent MRI, including the posterior fossa's high-resolution volumetric T2 sequence (three-dimensional constructive interference in steady state (3D-CISS)), were assessed. Patients with a history of audiovestibular symptoms (tinnitus/dizziness/vertigo/sensorineural hearing loss), intracranial tumor, vascular lesions, intracranial surgery, brain radiation therapy, traumatic brain injury, poor image quality, and MRI scans without 3D-CISS sequences were excluded. Two radiologists independently reviewed 114 (228 sides) MRI studies for the vascular loop of AICA in the CPA cistern and the extension of the AICA loop into the ipsilateral internal acoustic meatus which was graded by Chavda's classification. Results The prevalence of vascular loop of AICA in the CPA cistern was as high as 47.6% in asymptomatic patients. Grade I Chavda vascular loop was the most common type followed by type II, with type III being the least common type. Conclusions Knowledge regarding the high prevalence of the AICA loop in the asymptomatic population and the lack of significant correlation between the presence of the AICA loop and otovestibular symptoms should be considered in preoperative planning for decompression procedures.

To be thorough or tailored: influence of the arachnoid dissection range on the surgical outcomes of microvascular decompression for hemifacial spasm.

As one of the most fundamental elements in exposure and decompression, the dissection of arachnoid has been rarely correlated with the surgical results in studies on Microvascular decompression (MVD) procedures for Hemifacial spasm (HFS). Patients' records of the HFS cases treated with MVD from January 2016 to December 2021 in our center was retrospectively reviewed. The video of the procedures was inspected thoroughly to evaluate the range of dissection of arachnoid. Four areas were defined in order to facilitate the evaluation of the dissection range. The correlation between the arachnoid dissection and the surgical outcomes were analyzed. The arachnoid structures between the nineth cranial nerve and the seventh, eighth cranial nerves were dissected in all cases, other areas were entered based on different consideration. The rate of neurological complications of the extended dissection pattern group was higher than that of the standard pattern group (P < 0.05). The procedures in which the arachnoid structure above the vestibulocochlear nerve was dissected, led to more neurological complications (P < 0.05). Thorough dissection as an initial aim for all cases was not recommended in MVD for HFS, arachnoid dissection should be tailored to achieving safety and effectiveness during the procedure.