Endonasal Endoscopic Odontoidectomy in Ventral Diseases of the Craniocervical Junction: Results of a Multicenter Experience

Simultaneous resection of pituitary adenoma and clipping of aneurysm through endoscopic endonasal approach: a case report

Pituitary adenomas and intracranial aneurysms are prevalent neurosurgical conditions, but their simultaneous presence is uncommon, affecting only 0.5%-7.4% of those with pituitary adenomas. The strategy of treating aneurysms endovascularly before removing pituitary adenomas is widely adopted, yet reports on addressing both conditions at once through an endoscopic endonasal approach (EEA) are scarce. We present a case involving a pituitary adenoma coupled with an anterior communicating artery aneurysm. Utilizing the EEA, we excised the adenoma and clipped the aneurysm concurrently. The patient recovered well post-surgery, with follow-up assessments confirming the successful resolution of both the adenoma and aneurysm. We proved the feasibility of the EEA in the treatment of pituitary adenomas with anterior communicating artery aneurysms under specific anatomical relationships and close intraoperative monitoring.

Chiari I malformation: management evolution and technical innovation

BACKGROUND AND DEFINITION

In recent years thanks to the growing use of radiological assessment, Chiari I malformation became one of the major diseases for a neurosurgeon to deal with. CIM can be classified according to the extent of cerebellar tonsil tip into the foramen magnum being a protrusion over five mm considered pathological. Such a disease is a heterogeneous condition with a multifactorial pathogenetic mechanism that can subdivided into a primary and secondary form. Regardless of the form, it seems that CIM is the result of an imbalance between the volume of the braincase and its content. Acquired CIMs are secondary to conditions causing intracranial hypertension or hypotension while the pathogenesis of primary forms is still controversial.

PATHOGENESIS AND TREATMENT

There are several theories in the literature but the most accepted one implies an overcrowding due to a small posterior cranial fossa. While asymptomatic CIM do not need treatment, symptomatic ones prompt for surgical management. Several techniques are proposed being the dilemma centered in the need for dural opening procedures and bony decompression ones.

CONCLUSION

Alongside the paper, the authors will address the novelty presented in the literature on management, diagnosis and pathogenesis in order to offer a better understanding of such a heterogeneous pathology.

Approaching Intradural Lesions of the Anterior Foramen Magnum and Craniocervical Junction: Anatomical Comparison of the Open Posterolateral and Anterior Extended Endonasal Endoscopic Approaches

BACKGROUND

Lesions of the foramen magnum (FM) and craniocervical junction area are traditionally managed surgically through anterior, anterolateral, and posterolateral skull-base approaches. This anatomical study aimed to compare the usefulness of a modified extended endoscopic approach, the so-called far-medial endonasal approach (FMEA), versus the traditional posterolateral far-lateral approach (FLA).

METHODS

Ten fixed silicon-injected heads specimens were used in the Skull Base ENT-Neurosurgery Laboratory of the University Hospital of Strasbourg, France. A total of 20 FLAs and 10 FMEAs were realized. A high-resolution computed tomography scan was performed for quantitative analysis of the different approaches. The analysis aimed to estimate the extent of surgical exposure and freedom of movement (maneuverability) through the operating channel using a polygonal surface model to obtain a morphometric estimation of the area of interest (surface and volume) on postdissection computed tomography scans using Slicer 3D software.

RESULTS

FMEA allows for a more direct route to the anterior FM, with wider brainstem exposure compared with the FLA and an excellent visualization of all anterior midline structures. The limitations of the FMEA include the deep and narrow surgical corridor and difficulty in reaching lesions located laterally over the jugular foramen and hypoglossal canal.

CONCLUSIONS

The FMEA and FLA are both effective surgical routes to reach FM and craniocervical junction lesions. Modern skull base surgeons should have a good command of both because they appear complementary. This anatomical study provides the tools for comprehensive preoperative evaluations and selection of the most appropriate surgical approach.

Endoscopic Endonasal Approach to the Craniovertebral Junction Lesions: A Case Series of 18 Patients

Introduction  Odontoid pathologies constitute a special category because they may lead to instability. Instability is defined by abnormal spinal alignment under physiologic conditions (loads) such as standing, walking, bending, or lifting. Since instability poses a risk of cord damage, surgical interventions may be required for durable long-term stabilization. This study demonstrates operative technique and results of endoscopic endonasal approach to the odontoid pathologies. Methods  We conducted a retrospective study involving 18 patients who underwent endoscopic endonasal odontoidectomy (EEO) due to craniovertebral pathologies. Demographic data, clinical features of the patients, risk factors, and intraoperative and postoperative complications were reported in this series. Results  Satisfactory outcomes achieved in 16 patients based on comparing the modified Rankin scale before and after the surgery ( p  = 0.0001). The mean duration for EEO was 232.6 ± 18.8 minutes. The mean blood loss during surgery was 386.67 ± 153.04 mL. The mean duration of hospital stay was 7 days. All patients were extubated within a few hours after surgery. Despite of successful anterior decompression in the aforementioned cases, intraoperative cerebrospinal fluid (CSF) leakage, postoperative meningitis, and pulmonary thromboembolism occurred as complications. However, two intraoperative CSF leakages were managed by direct dural repair and fat graft; two patients died due to postoperative meningitis and pulmonary thromboembolism at 7 and 4 days after the second surgery. Conclusion  In conclusion, EEO can be effectively used for anterior decompression of the odontoid pathologies, despite the risk of complications.

Effect of modified clivoaxial angle on surgical decision making and treatment outcomes in patients with Chiari malformation type 1

Introduction

Chiari malformation type 1 (CM1), a complex pathological developmental disorder of the craniovertebral junction, is typically characterized by herniation of the cerebellar tonsils from the foramen magnum. Treatment using posterior fossa decompression alone without taking the ventral cervico-medullary compression into consideration may lead to unsatisfactory treatment outcomes. The current study evaluated the utility of the modified clivoaxial angle (MCAA) in assessing ventral compression and also examined its effect on treatment outcomes.

Method

This retrospective study included 215 adult patients who underwent surgical treatment for CM1 at one medical center over a 10-year period. The following surgical techniques were used to decompress the posterior fossa: (a) PFD: bone removal only; (b) PFDwD: bone removal with duraplasty; and (c) CTR: cerebellar tonsil resection. The morphometric measurements of the craniovertebral junction (including MCAA) were recorded using preoperative images, and the postoperative clinical status was evaluated using the Chicago Chiari outcome scale (CCOS).

Results

MCAA was positively correlated with the CCOS score and also independently predicted treatment outcome. To enable Receiver operating characteristic (ROC) curve analysis of CCOS scores, the patients were divided into three groups based on the MCAA cut-off values, as follows: (a) severe (n = 43): MCAA ≤ 126; (b) moderate (n = 86): 126 < MCAA ≤ 138; and (c) mild (n = 86): MCAA > 138. Group a exhibited severe ventral cervico-medullary compression (VCMC), and their CCOS scores for the PFD, PFDwD, and CTR groups were 11.01 ± 1.2, 11.24 ± 1.3, and 13.01 ± 1.2, respectively (p < 0.05). The CCOS scores increased with widening of the MCAA angle in all surgical groups (p < 0.05). Furthermore, patients with mild MCAA (>138°) exhibited 78% regression of syringomyelia, and this was significantly greater than that observed in the other groups.

Discussion

MCAA can be used in the selection of appropriate surgical techniques and prediction of treatment outcomes, highlighting the importance of preoperative evaluation of ventral clivoaxial compression in patients with CM1.

Endoscopic Endonasal Skull Base Surgery Complication Avoidance: A Contemporary Review

The endoscopic endonasal approach (EEA) provides a direct trajectory to ventral skull base lesions, avoidance of brain retraction, and clear visualization of cranial nerves as they exit skull base foramina. Despite these benefits, the EEA is not without complications. Here, we review published literature highlighting complications associated with the EEA including cerebrospinal fluid (CSF) leak, cranial nerve (CN) dysfunction, pituitary gland dysfunction, internal carotid artery (ICA) injury, infection, and others; we place special emphasis on discussing the prevention of these complications. As widespread adoption of the EEA continues, it becomes critical to educate surgeons regarding potential complications and their prevention while identifying gaps in the current literature to guide future research and advances in clinical care.

The Impact of C1 Anterior Arch Preservation on Spine Stability After Odontoidectomy: Systematic Review and Meta-Analysis

BACKGROUND

Odontoidectomy for symptomatic irreducible ventral brainstem compression at the craniovertebral junction may result in spine instability requiring subsequent instrumentation. There is no consensus on the importance of C1 anterior arch preservation in prevention of iatrogenic instability. We conducted a systematic review of the impact of C1 anterior arch preservation on postodontoidectomy spine stability.

METHODS

PubMed, Embase, Scopus, Web of Science, and Cochrane were searched following the PRISMA guidelines to include studies of patients undergoing odontoidectomy. Random-effect model meta-analyses were performed to compare spine stability between C1 anterior arch preservation versus removal and posttreatment outcomes between transoral approaches (TOAs) versus endoscopic endonasal approaches (EEAs).

RESULTS

We included 27 studies comprising 462 patients. The most common lesions were basilar invagination (73.3%) and degenerative arthritis (12.6%). Symptoms included myelopathy (72%) and neck pain (43.9%). Odontoidectomy was performed through TOA (56.1%) and EEA corridors (34.4%). The C1 anterior arch was preserved in 16.7% of cases. Postodontoidectomy stabilization was performed in 83.3% patients. Median follow-up was 27 months (range, 0.1-145). Rates of spine instability were significantly lower (P = 0.004) when the C1 anterior arch was preserved. Postoperative clinical improvement and pooled complications were reported in 78.8% and 12.6% of patients, respectively, with no significant differences between TOA and EEA (P = 0.892; P = 0.346). Patients undergoing EEA had significantly higher rates of intraoperative cerebrospinal fluid leaks (P = 0.002).

CONCLUSIONS

Odontoidectomy is safe and effective for treating craniovertebral junction lesions. Preservation of the C1 anterior arch seems to improve maintenance of spine stability. TOA and EEA show comparable outcomes and complication rates.

Endoscopic endonasal odontoidectomy: a long-term follow-up results for a cohort of 21 patients

BACKGROUND

Endoscopic endonasal odontoidectomy (EEO) has been described as a potential approach for craniovertebral junction (CVJ) disease which could cause anterior bulbomedullary compression and encroaching. Due to the atlantoaxial junction's uniqueness and complex biomechanics, treating CVJ pathologies uncovers the challenge of preventing C1-C2 instability. A large series of patients treated with endonasal odontoidectomy is reported, analyzing the feasibility and necessity of whether or not to perform posterior stabilization. Furthermore, the focus is on the long-term follow-up, especially those whom only underwent partial C1 arch preservation without posterior fixation.

METHODS

This study is a retrospective analysis of patients with ventral spinal cord compression for non-reducible CVJ malformation, consecutively treated with EEO from July 2011 to March 2019. Postoperative dynamic X-ray and CT scans were obtained in each case in order to document CVJ decompression as well as to exclude instability. The anterior atlas-dens interval, posterior atlas-dens interval and C1-C2 total lateral overhang were measured as a morphological criteria to determine upper cervical spine stability.

RESULTS

Twenty-one patients (11:10 F:M) with a mean age of 60.6 years old at the time of surgery (range 34-84 years) encountered the inclusion criteria. For all 21 patients, a successful decompression was achieved at the first surgery. In 11 patients, the partial C1 arch integrity did not require a posterior cervical instrumentation on the bases of postoperative and constant follow-up radiological examination. In 13 cases, an improvement of motor function was recorded at the time of discharge. Only one patient had further motor function improvement at follow-up. Among the patients that did not show any significant motor change at discharge, 4 patients showed an improvement at the last follow-up.

CONCLUSIONS

The outcomes, even in C1 arch preservation without posterior fixation, are promising, and it could be said that the endonasal route potentially represents a valid option to treat lesions above the nasopalatine line.

Endoscopic Endonasal Versus Transoral Odontoidectomy for Non-Neoplastic Craniovertebral Junction Disease: A Case Series

BACKGROUND

Odontoidectomy is a challenging yet effective operation for decompression of non-neoplastic craniovertebral junction disease. Though both the endoscopic endonasal approach (EEA) and the transoral approach (TOA) have been discussed in the literature, there remain few direct comparisons between the techniques.

OBJECTIVE

To evaluate the perioperative outcomes of EEA vs TOA odontoidectomy.

METHODS

A retrospective review of all cases undergoing odontoidectomy by either the EEA or TOA was performed. Attention was paid to the need for prolonged nutritional support, prolonged respiratory support, and hospitalization times.

RESULTS

During the study period between 2000 and 2018, 25 patients underwent odontoid process resection (18 TOA and 7 EEA). The most common indication for surgery was basilar invagination. Hospital length of stay, intensive care unit length of stay, and intubation days were all significantly shorter in the EEA group compared to the TOA group (P < .01, P = .01, P < .01, respectively). Prolonged nutritional support in the form of a gastrostomy tube was required in 5 patients and tracheostomy was required in 4 patients; all of these underwent odontoidectomy by the TOA. There was no statistical difference in neurological outcomes between the EEA and TOA groups (P = .17).

CONCLUSION

Odontoidectomy can be performed safely through both the EEA and TOA. The results of this study suggest the EEA has shorter hospitalizations and a lower probability of requiring prolonged nutritional support. These advantages are likely the results of decreased oropharyngeal mucosa disruption as compared to the TOA.

Primary Endoscopic Endonasal Management of Giant Pituitary Adenomas: Outcome and Pitfalls from a Large Prospective Multicenter Experience

Simple Summary

Giant pituitary adenomas are highly invasive tumors whose treatment is challenging. Surgery is their management mainstay. However, there is no consensus about the type of approach. Open transcranial, microscopic, and endoscopic trans-sphenoidal approaches have all been employed, alone or in combination. Extended endoscopic endonasal techniques may represent a versatile and safe one-stage approach. Our research aimed at evaluating prospectively their applicability, effectiveness, and safety in a multicenter series, to acquire further evidence toward its use in the treatment of those challenging lesions. Ninety-six patients were recruited and followed-up for 52.4 months on average. Most of them (81.2%) presented with visual deficits and >50% had various degrees of adenohypophysis insufficiency. Resection of at least 75% of initial volume was achieved in all cases, with 98.7% visual improvement, >50% endocrine deficit recovery and a permanent complication rate of 4.2%, indicating extended endoscopic endonasal approaches as a valuable treatment option.

Abstract

Purpose: To evaluate factors influencing clinical and radiological outcome of extended endoscopic endonasal transtuberculum/transplanum approach (EEA-TTP) for giant pituitary adenomas (GPAs). Methods: We recruited prospectively all consecutive GPAs patients undergoing EEA-TTP between 2015 and 2019 in 5 neurosurgical centers. Preoperative clinical and radiologic features, visual and hormonal outcomes, extent of resection (EoR), complications and recurrence rates were recorded and analyzed. Results: Of 1169 patients treated for pituitary adenoma, 96 (8.2%) had GPAs. Seventy-eight (81.2%) patients had visual impairment, 12 (12.5%) had headaches, 3 (3.1%) had drowsiness due to hydrocephalus, and 53 (55.2%) had anterior pituitary insufficiency. EoR was gross or near-total in 46 (47.9%) and subtotal in 50 (52.1%) patients. Incomplete resection was associated with lateral suprasellar, intraventricular and/or cavernous sinus extension and with firm/fibrous consistence. At the last follow-up, all but one patient (77, 98.7%) with visual deficits improved. Headache improved in 8 (88.9%) and anterior pituitary function recovered in 27 (50.9%) patients. Recurrence rate was 16.7%, with 32 months mean recurrence-free survival. Conclusions: EEA-TTP is a valid option for GPAs and seems to provide better outcomes, lower rate of complications and higher EoR compared to one- or multi-stage microscopic, non-extended endoscopic transsphenoidal, and transcranial resections.

Endoscopic transnasal/transoral odontoid resection in children: results of a combined neurosurgical and otolaryngological protocolized, institutional approach

OBJECTIVE

Odontogenic ventral brainstem compression can be a source of significant morbidity in patients with craniocervical disease. The most common methods for odontoidectomy are the transoral and endoscopic endonasal routes. In this study, the authors investigated the use of an institutional protocol for endoscopic transnasal/transoral odontoidectomy in the pediatric population.

METHODS

From 2007 to 2017, a multidisciplinary institutional protocol was developed and refined for the evaluation and treatment of pediatric patients requiring odontoidectomy. Preoperative assessment included airway evaluation, a sleep study (if indicated), discussion of possible tonsillectomy/adenoidectomy, and thorough imaging review by the neurosurgery and otolaryngology teams. Further preoperative anesthesia consultation was obtained for difficult airways. Intraoperatively, adenoidectomy was performed at the discretion of otolaryngology. The odontoidectomy was performed as a combined procedure. Primary posterior pharyngeal closure was performed by the otolaryngologist. The postoperative protocol called for immediate extubation, advancement to a soft diet at 24 hours, and no postoperative antibiotics. Outcome variables included time to extubation, operative time, estimated blood loss, hospital length of stay, and postoperative complications.

RESULTS

A total of 13 patients underwent combined endoscopic transoral/transnasal odontoid resection with at least 3 years of follow-up. All patients had stable to improved neurological function in the postoperative setting. All patients were extubated immediately after the procedure. The average operative length was 201 ± 46 minutes, and the average estimated blood loss was 44.6 ± 40.0 ml. Nine of 13 patients underwent simultaneous tonsillectomy and adenoidectomy. The average hospital length of stay was 6.6 ± 5 days. The first patient in the series required revision surgery for removal of a small residual odontoid. One patient experienced pharyngeal flap dehiscence requiring revision.

CONCLUSIONS

A protocolized, institutional approach for endoscopic transoral/transnasal odontoidectomy is described. The use of a combined, multidisciplinary approach leads to streamlined patient management and favorable outcomes in this complex patient population.

Natural History, Neuroradiological Workup, and Management Options of Chronic Atlantoaxial Rotatory Fixation Caused by Drug-Induced Cervical Dystonia

Atlantoaxial rotatory fixation (AARF) resulting from drug-induced cervical dystonia (DICD) represents an extremely rare complication of antipsychotic treatment, requiring a comprehensive assessment of pharmacologic therapy and timely radiologic workup. We report a chronic case of Fielding type I, Pang type I AARF secondary to schizophrenia treatment in a 16-year-old girl, along with a review of the literature on the management challenges posed in this condition. In this scenario, torticollis may just represent the tip of the iceberg, and only an effective multidisciplinary approach increases the chances of satisfactory correction with closed reduction, hence avoiding the burden of more invasive treatment options.

[Treatment of tuberculosis in craniovertebral junction]

Objective

To investigate the method of treating tuberculosis in the craniovertebral junction and its effectiveness.

Methods

The clinical data of 18 patients with tuberculosis in the craniovertebral junction between July 2010 and January 2019 was analyzed retrospectively. There were 14 males and 4 females, aged 21 months to 75 years (median, 35 years). The disease duration ranged from 2 weeks to 60 months (median, 4 months), and the affected segment was C ₀-C ₃. Preoperative visual analogue scale (VAS) score was 6.7±1.5 and the Japanese Orthopaedic Association (JOA) score was 16.1±1.8. The American Spinal Cord Injury Association (ASIA) grading system was applied to classify their neurological functions, according to which there were 6 cases of grade D and 12 cases of grade E. Among 18 patients, 4 patients underwent conservative treatment, 1 patient removed tuberculosis via transoral approach, 1 patient removed tuberculosis via posterior cervical approach, and 12 patients removed tuberculosis via transoral approach immediately after posterior cervical (atlantoaxial or occipitalcervical) fusion and internal fixation. The VAS score, ASIA grading, and JOA score were applied to evaluate effectiveness. X-ray film, CT, and MRI were taken after treatment to evaluate the tubercular recurrence, cervical stability, and bone healing.

Results

All the patients were followed up 3 to 42 months (median, 12 months). At 3 months after treatment, the VAS score was 1.7±1.0, showing significant difference when compared with preoperative score ( t=15.000, P=0.000); and the JOA score was 16.7±1.0, showing no significant difference when compared with preoperative score ( t=1.317, P=0.205). According to ASIA grading, 6 patients with grade D before treatment had upgraded to grade E after treatment, while the remaining patients with grade E had no change in grading. The imaging examinations showed the good stability of the cervical spine. All patients had complete tuberculosis resection and no recurrence, and the patients who underwent internal fixation via posterior cervical approach achieved atlantoaxial or occipitalcervical bone fusion.

Conclusion

On the premise of regular chemotherapy, if there is no huge abscess causing dysphagia or dyspnea, atlantoaxial instability, and neurological symptoms, patients can undergo conservative treatment. If not, however, the transoral approach can be used to completely remove the tuberculosis lesion in the craniovertebral junction. One-stage debridement via transoral approach combined with posterior cervical fusion and internal fixation can achieve satisfactory effectiveness.

Retro-Odontoid Pseudotumor Formation in the Context of Various Acquired and Congenital Pathologies of the Craniovertebral Junction and Surgical Techniques

Retro-odontoid pseudotumor formation consists of an abnormal growth of granulation tissue typically posterior to the odontoid process, resulting as a manifestation of atlantoaxial instability. This instability can occur as a result of conditions ranging from severe mechanical trauma to metabolic disease or autoimmune conditions such as rheumatoid arthritis. A pseudotumor may impinge on the spinal nerves or even the spinal cord and brainstem, manifesting symptoms from severe neck pain to cervicomedullary compression or myelopathy, and in some cases even sudden death. The objective of this review is to consolidate the findings in published case reports and relevant prior literature reviews regarding the formation of retro-odontoid pseudotumor. We address the pathophysiology involved in acquired and congenital pseudotumor formation, including those associated with rheumatoid arthritis (panni). Additionally, we discuss past and current operative techniques designed to curtail and ultimately regress a retro-odontoid pseudotumor and pannus. Surgical techniques that are addressed include ventral decompression (both transoral and transnasal), dorsal decompression, and indications for posterior instrumentation in pannus formation, particularly in cases that may be sufficiently treated in lieu of an anterior approach. Finally, we will examine the role of external orthoses as both a method of conservative treatment as well as a potential adjunct to the aforementioned surgical procedures.

Intraoperative Fluid Management in Patients Undergoing Spine Surgery: A Narrative Review

Fluid management has been widely recognized as an important component of the perioperative care in patients undergoing major procedures including spine surgeries. Patient- and surgery-related factors such as age, length of the surgery, massive intraoperative blood loss, and prone positioning, may impact the intraoperative administration of fluids. In addition, the type of fluid administered may also affect post-operative outcomes. Published literature describing intraoperative fluid management in patients undergoing major spine surgeries is limited and remains controversial. Therefore, we reviewed current literature on intraoperative fluid management and its association with post-operative complications in spine surgery.

Anterior release without odontoidectomy for irreducible atlantoaxial dislocation: transoral or endoscopic transnasal?

PURPOSE

To compare transoral and endoscopic transnasal anterior release without odontoidectomy and posterior reduction and fixation to treat irreducible atlantoaxial dislocation (IAAD).

METHODS

From June 2006 to January 2017, 35 consecutive patients with IAAD underwent transoral (Tr-Oral group) or endoscopic transnasal (Tr-Nasal group) release and posterior fixation and fusion in our department. Clinical neurological recovery (Japanese Orthopedic Association (JOA) score) and radiological reduction parameters including atlantodontoid interval (ADI), space available for the cord (SAC) and cervicomedullary angle (CMA) were analyzed and compared. The operation duration, blood loss, length of intensive care unit (ICU)/hospital stay and complications were recorded.

RESULTS

All 35 patients (18 and 17 patients in the Tr-Oral and Tr-Nasal groups, respectively) were followed up for a mean of 36.4 months (range, 21-60 months). All patients achieved excellent anatomical reduction and clinical neurological recovery, with no significant differences between the two groups. The JOA score, ADI, SAC and CMA were not significantly different between the two groups at various postoperative points. Although the Tr-Oral group had shorter operation time and less blood loss than the Tr-Nasal group, the Tr-Nasal group tended to have a significantly shorter hospital/ICU stay, earlier extubation and earlier oral intake than the Tr-Oral group.

CONCLUSION

The transoral and endoscopic transnasal approaches can achieve equivalent release and reduction effects when treating IAAD. Compared to the transoral approach, the endoscopic transnasal route is less invasive with earlier extubation and oral intake, shorter hospital/ICU stays and lower medical costs, which is conducive to enhanced recovery after surgery.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Clinical Outcomes of Endoscopic Endonasal Odontoidectomy: A Single-Center Experience

BACKGROUND

Odontoidectomy for basilar invagination and craniovertebral junction pathology traditionally has been performed using a transoral route. However, the endoscopic endonasal approach to the anterior craniovertebral junction may offer safer and more effective access when compared with transoral approaches. The objective of this study is to review the surgical outcomes and complications associated with endoscopic endonasal odontoidectomy.

METHODS

This study is a retrospective chart review of all adult patients who underwent an endoscopic endonasal odontoidectomy at a single tertiary care center between January 2011 and May 2019.

RESULTS

Seventeen patients who underwent endoscopic endonasal odontoidectomy were included. The median age at admission was 67 years (range: 33-84 years) and 65% of the patients were female. One patient (1/17, 6%) had vertebral artery injury, which had to be coiled with no neurologic deficits, and 4 patients (4/17, 24%) had intraoperative CSF leaks with no postoperative leak. Fourteen (14/17, 82%) patients were extubated by postoperative day 1. Three patients (3/17, 18%) developed postoperative sinus infections and required antibiotics. Eight patients (8/17, 47%) developed transient postoperative dysphagia. One patient (1/17, 6%) had postoperative epistaxis and 1 patient (1/17, 6%) had postoperative lower cranial nerve symptoms. The median length of hospital stay was 13 days (range: 2-44 days).

CONCLUSIONS

Although the transoral approach has been the traditional route for anterior decompression of the craniovertebral junction, endoscopic endonasal odontoidectomy is a feasible and well-tolerated procedure associated with satisfactory patient outcomes and low morbidity.

Which neuroimaging techniques are really needed in Chiari I? A short guide for radiologists and clinicians

PURPOSE

To describe the most appropriate techniques and suggested protocols meant to address the various scenarios that clinicians and pediatric neurosurgeons may face in their day-to-day practice connected with Chiari I.

METHODS

Current literature related to image indications and findings in Chiari I has been reviewed. The authors focused on both standard and advanced techniques for clinical diagnosis and preoperative planning purposes.

DISCUSSION AND CONCLUSION

The complexity of providing neuroimaging guidelines for children investigated for Chiari I lies in defining the most appropriate neuroradiology tool to approach what is in fact a very heterogeneous condition with different etiopathogenetic mechanisms and associated abnormalities. Other variables that may influence the diagnostic strategy include the age of the patient, the presence of additional pathological conditions, the type of presenting symptoms, and the indication for surgical or conservative management. Although the average age at time of diagnosis is 10 years, the initial diagnosis may be done at any age, and the referral for neuroradiology workup may come from general practitioners/pediatricians, orthopedic surgeons, and endocrinologists following various baseline investigations including plain x-rays of skull and spine and/or CT head and/or MRI brain and spine.

A Pilot Study of Percutaneous Interlaminar Endoscopic Lumbar Sequestrectomy: A Modern Strategy to Tackle Medically-Refractory Radiculopathies and Restore Spinal Function

Objective

Angled scopes allow 360° visualization, which makes percutaneous endoscopic techniques (percutaneous endoscopic lumbar discectomy, PELD) particularly attractive for sequestrectomies, which entail the removal of extruded lumbar disc fragments that have migrated caudally or cranially between the ligaments, foramina, and neural structures, while preserving the disc. Although many different PELD techniques are currently available, not all of them are suitable for sequestrectomies; furthermore, long-term follow-up data are unfortunately lacking.

Methods

A pilot study was conducted on a cohort of 270 patients with lumbar radiculopathy undergoing minimally invasive spine surgery (PELD or microdiscectomy), of whom only 7 were eligible for endoscopic interlaminar sequestrectomy with disc preservation. The patients’ baseline conditions and clinical outcomes were measured with the Oswestry Disability Index and a visual analogue scale. Long-term follow-up was conducted using satisfaction questionnaires that were based on the MacNab criteria and administered by medical/nursing personnel not involved in their primary surgical management.

Results

EasyGo system was eventually used in 5 PELD cases. No dural tears, infections, or nerve root injuries were recorded in patients undergoing sequestrectomy. Surgical events, including blood loss and overall length of hospital stay, did not differ significantly among the 270 patients. In the group treated with endoscopic sequestrectomy, no recurrences or complications were noted during a follow-up of 3 years, and an excellent degree of satisfaction was reported.

Conclusion

We provide OCEBM (Oxford Centre for Evidence-Based Medicine) level 3 evidence that interlaminar endoscopic sequestrectomy is a tailored and well-tolerated surgical option; nonetheless, a cost-effectiveness analysis assessing the interval until return to working activities and long-term benefits is warranted.

Endoscopic Endonasal Approach to the Upper Cervical Spine for Decompression of the Cervicomedullary Junction Following Occipitocervical Fusion

Basilar invagination is defined as abnormal upward and/or posterior displacement of the odontoid leading to ventral compression of the cervicomedullary junction. This condition leads to lower cranial neuropathies, sensorimotor deficits, and myelopathy. These symptoms can persist even after posterior decompression, which is an indication for ventral decompression. Transoral approaches to the upper cervical spine carry significant morbidity, limiting their utility. The endonasal approach to the upper cervical spine presents an alternative for patients with amenable anatomy. In this report, we present a case of a patient with type 1 Chiari malformation with persistent symptoms despite adequate posterior decompression through suboccipital craniectomy and C1 laminectomy. A retroflexed odontoid and dorsal clival bone lip contributed to persistent cervicomedullary compression. To address this, we performed a 2-stage procedure: an occiput-to-C4 fusion followed by endoscopic endonasal approach for dorsal clivusectomy, C1 anterior arch resection, and odontoidectomy. In the associated video, Supplemental Digital Content 1 (http://links.lww.com/CLINSPINE/A52), we demonstrate the step-by-step approach for this anterior approach including positioning, dissection through the nasopharyngeal fascia, identification of bony landmarks using an intraoperative CT scanner with 3-dimensional navigation guidance, and drilling/bony decompression of the dorsal clivus, C1, and C2. We also discuss key pearls, pitfalls, and preoperative/postoperative considerations critical to successful outcomes.

How I do it: Endoscopic endonasal approach for odontoid resection

BACKGROUND

Since it was first described in 2005 by Kassam et al., the technique of endoscopic resection of the odontoid by the transnasal route has gained broad acceptance. Its advantages over the transoral approach are currently well-demonstrated.

METHOD

The authors present the surgical technique developed by the senior author in a series of 12 patients, specifying the planning, complications avoidance and showing a film of the operating technique.

CONCLUSION

Endoscopic endonasal odontoidectomy is an effective procedure with low morbidity. This technique has a place in the treatment of complex pathologies of the craniovertebral junction and has many advantages over the transoral route.