Innovations in the Art of Microneurosurgery for Reaching Deep-Seated Cerebral Lesions

Deep-seated cerebral lesions have fascinated and frustrated countless surgical innovators since the dawn of the microneurosurgical era. To determine the optimal approach, the microneurosurgeon must take into account the characteristics and location of the pathological lesion as well as the operator's range of technical expertise. Increasingly, microneurosurgeons must select between multiple operative corridors that can provide access to the surgical target. Innovative trajectories have emerged for many indications that provide more flexible operative angles and superior exposure but result in longer working distances and more technically demanding maneuvers. In this article, we highlight 4 innovative surgical corridors and compare their strengths and weaknesses against those of more conventional approaches. Our goal is to use these examples to illustrate the following principles of microneurosurgical innovation: (1) discover more efficient and flexible exposures with superior working angles; (2) ensure maximal early protection of critical neurovascular structures; and (3) effectively handle target pathology with minimal disruption of normal tissues.

Unilateral Occipital Transtentorial Approach with Multimodal Assistance for Resection of Large Supracerebellar Hemangioblastomas: Preliminary Experience of 2 Cases

BACKGROUND

The surgical resection of large supracerebellar hemangioblastomas (SHBs) is exceptionally challenging due to their vascularity and deep anatomic location and is associated with a high risk of postoperative complications and mortality. Access to the posterior incisural space can be achieved by either an infratentorial supracerebellar approach or occipital transtentorial approach (OTA). However, the optimal surgical strategy has not yet been established. Here, we report 2 cases of large SHBs that were successfully and safely resected via a unilateral OTA with multimodal assistance.

CASE DESCRIPTION

Two patients presented to our hospital with ataxia due to large, solid SHBs. After preoperative embolization, gross total resection of the SHBs was achieved via an OTA. Furthermore, endoscopic assistance was used to resect the remnant portion of the tumor in the second patient. Both patients experienced transient ataxia but were discharged from the hospital without serious complications.

CONCLUSIONS

The combination of an OTA with preoperative embolization and endoscopic assistance may reduce the intraoperative risk and contribute to improved outcome in patients with such clinically challenging tumors.

Recurrent Rathke's Cleft Cysts: Incidence and Surgical Management in a Tertiary Pituitary Center over 2 Decades

BACKGROUND

Limited data exist pertaining to outcomes following surgery for recurrent Rathke's cleft cysts (RCC).

OBJECTIVE

To determine treatment outcomes in patients undergoing reoperation for recurrent or residual RCCs.

METHODS

A retrospective analysis of 112 consecutive RCC operations in 109 patients between 1995 and 2017 was conducted.

RESULTS

Eighteen patients underwent 21 RCC reoperations with a mean follow-up of 58 mo. Patient symptoms prior to reoperation included headaches (14, 66.7%) and vision loss (12, 57.1%). Thirteen of 18 patients (72.2%) required hormone supplementation prior to reoperation including 5 with diabetes insipidus (DI). Mean RCC diameter was 16 mm and 76% had suprasellar extension. Compared to index RCC cases, intraoperative cerebrospinal fluid leak repair was more common in reoperation cases (15/21, 71% vs 43/91, 47%, P = .05). There was 1 carotid artery injury without neurological sequelae, and 2 postoperative cerebrospinal fluid (CSF) leaks (9.5%). Rates of transient hyponatremia (3/10, 30% vs 4/91, 4.4%, P = .04) and transient DI (5/10, 50% vs 17/91, 18.7%, P = .04) were higher in the reoperation vs index group. Improved headaches and vision were reported in 4/12 (33%) and 8/12 (61.5%) of RCC reoperation patients, respectively. Two patients developed new permanent DI. A higher proportion of reoperation patients had RCC squamous metaplasia (24% vs 5.4%, P = .02) or wall inflammation (42.9% vs 2.2%, P < .001) on pathological examination.

CONCLUSION

Reoperation for RCCs is generally safe at tertiary pituitary centers and often results in improved vision. Hypopituitarism is less likely to improve following reoperation for recurrent RCCs. Several histopathological features may help characterize "atypical RCCs" with a higher likelihood of recurrence/progression.

Basilar invagination associated with chiari malformation type I: A literature review

Basilar invagination (BI) and Chiari malformation type I (CM-I) are very important anomalies that introduce instability and compression in the occipitocervical transition region and have complex clinical characteristics. These anomalies vary according to the affected structures. The present study revises current knowledge regarding the anatomy, anatomo-physiology, clinical manifestations, and radiological findings of these entities and the associated surgical treatment approaches. A bibliographic survey was performed through a search in the Medline, PubMed, SciELO, Science and LILACS databases. When associated, these craniovertebral malformations result in neurological deficits due to neural parenchyma compression; however, the presence of microtraumas due to repetitive lesions caused by the bulb and cervical marrow instability has been highlighted as a determinant dysfunction. Surgical treatment is controversial and has many technical variations. Surgery is also challenging due to the complex anatomical characteristics and biomechanics of this region. Nevertheless, advances have been achieved in our understanding of related mechanisms, and compression and atlantoaxial instability are considered key elements when selecting the surgical approach.

A Dual Approach for the Management of Complex Craniovertebral Junction Abnormalities: Endoscopic Endonasal Odontoidectomy and Posterior Decompression with Fusion

BACKGROUND

Ventral brainstem compression secondary to complex craniovertebral junction abnormality is an infrequent cause of neurologic deterioration in pediatric patients. However, in cases of symptomatic, irreducible ventral compression, 360° decompression of the brainstem supported by posterior stabilization may provide the best opportunity for improvement in symptoms. More recently, the endoscopic endonasal corridor has been proposed as an alternative method of odontoidectomy associated with less morbidity. We report the largest single case series of pediatric patients using this dual-intervention surgical technique. The purpose of this study was to evaluate the surgical outcomes of pediatric patients who underwent posterior occipitocervical decompression and instrumentation followed by endoscopic endonasal odontoidectomy performed to relieve neurologic impingement involving the ventral brainstem and craniocervical junction.

METHODS

Between January 2011 and February 2017, 7 patients underwent posterior instrumented fusion followed by endonasal endoscopic odontoidectomy at our unit. Standardized clinical and radiological parameters were assessed before and after surgery. A univariate analysis was performed to assess clinical and radiologic improvement after surgery.

RESULTS

A total of 14 operations were performed on 7 pediatric patients. One patient had Ehlers-Danlos syndrome, 1 patient had a Chiari 1 malformation, and the remaining 5 patients had Chiari 1.5 malformations. Average extubation day was postoperative day 0.9. Average day of initiation of postoperative feeds was postoperative day 1.0.

CONCLUSIONS

The combined endoscopic endonasal odontoidectomy and posterior decompression and fusion for complex craniovertebral compression is a safe and effective procedure that appears to be well tolerated in the pediatric population.

Origin site-based staging system of sinonasal inverted papilloma for application to endoscopic sinus surgery

Background

We aimed to assess the recurrence risk of sinonasal inverted papillomas (SNIPs), based on a staging system developed according to the originating site of SNIP.

Methods

A total of 200 patients with SNIP were enrolled, and a staging system was developed based on the originating sites and corresponding recurrence rates of tumor in the patients. In the verification phase, 675 patients with SNIPs were enrolled as above, and the originating sites of the SNIPs were confirmed by an endoscopic sinus surgery. Cluster analysis was performed to determine the stage for each SNIP.

Results

Overall, 608 patients completed the study. SNIP recurrence rates for stages 1‐4 were 0 (n = 43), 4.0% (n = 420), 13.4% (n = 134), 36.4% (n = 11), respectively (total = 6.4%).

Conclusions

The origin site‐based classification of SNIP may aid surgeons in selecting appropriate endoscopic surgical approaches to minimize the risk of recurrence.

Endoscopic endonasal resection of symptomatic Rathke cleft cysts: clinical outcomes and prognosis

The aim of this study is to investigate the clinical presentation and outcomes associated with endoscopic endonasal resection of Rathke cleft cysts (RCCs). The authors retrospectively studied a series of 13 patients who were diagnosed with RCCs after endoscopic endonasal resection at the Second Xiangya Hospital between June 2016 and December 2017. All 13 patients (8 women) underwent a purely endoscopic endonasal approach (EEA) for fenestration and aspiration of RCCs with excision of the cystic wall. The patient ages varied from 25 to 67 years (mean, 45.1 years), and the follow-up period ranged from 8 to 25 months (mean, 16.6 months). Headache was a presenting symptom in all 13 patients, with 11 (80%) out of the 13 having experienced postoperative improvement of their headaches. Six (46%) of the 13 patients were admitted with pituitary dysfunction, all of them had postoperative improvement. Four (31%) of the 13 patients had temporary postoperative pituitary dysfunction, although there was not any permanent pituitary dysfunction. Six patients had intraoperative complications with CSF leaks, and after the operation, three of them developed temporary diabetes insipidly, one of them had a postoperative infection, and another one had postoperative cerebrospinal fluid leaks, who was treated with absolute bed rest for 7 days. No patient experienced recurrent cysts. EEA is a safe and effective approach for the treatment of symptomatic RCCs. Notably, it is appreciated for protecting and restoring pituitary function; however, the postoperative recurrence rate still lacks a large sample related to the long time follow-up study. Complete aspiration of the cysts' contents with partial excision of the cyst wall is usually sufficient for treatment.

The full-endoscopic uniportal technique for decompression of the anterior craniocervical junction using the retropharyngeal approach: an anatomical feasibility study in human cadavers and review of the literature

Objective

Acute or progressive myelopathy may necessitate direct anterior decompression of the craniocervical junction and odontoidectomy. Different techniques with individual advantages and disadvantages can be used. In addition to the gold standard-the transoral approach-there is also increasing experience with the endoscopic transnasal technique. Other alternative methods are also being developed to reduce technical and perioperative problems. The aim of this anatomical study was to investigate the feasibility of the full-endoscopic uniportal technique with a retropharyngeal approach for decompression of the craniocervical junction, taking into consideration the specific advantages and disadvantages compared with conventional methods and the currently available data in the literature.

Methods

Five fresh adult cadavers were operated on. The endoscope used has a shaft cross-section of 6.9 × 5.9 mm and a 25° viewing angle. It contains an eccentric intraendoscopic working channel with a diameter of 4.1 mm. An anterior retropharyngeal approach was used. The anatomical structures of the anterior craniocervical junction were dissected and the bulbomedullary junction was decompressed.

Results

The planned steps of the operation were performed in all cadavers. The retropharyngeal approach allowed the target region to be accessed easily. The anatomical structures of the anterior craniocervical junction could be identified and dissected. The bulbomedullary junction could be adequately decompressed. No resections of the anterior arch of the atlas were necessary in the odontoidectomy.

Conclusions

Using the full-endoscopic uniportal technique with an anterior retropharyngeal approach, the craniocervical region can be adequately reached, dissected, and decompressed. This is a minimally invasive technique with the known advantages of an endoscopic procedure under continuous irrigation. The retropharyngeal approach allows direct, sterile access. The instruments are available for clinical use and have been established for years in other operations of the entire spine.

Utility of the Vidian Canal in Endoscopic Skull Base Surgery: Detailed Anatomy and Relationship to the Internal Carotid Artery

OBJECTIVE

To investigate key anatomic features of the vidian canal that have a critical role in planning and performing endoscopic skull base surgeries.

METHODS

We reviewed skull base computed tomographic images of 640 consecutive subjects. Studies were analyzed in axial, coronal and sagittal planes.

RESULTS

The mean (±SD) length of the vidian canal was 15.4 ± 2.0 mm in female subjects and 16.6 ± 1.7 mm in male subjects, and the difference between genders was statistically significant (P < 0.001). The most common rostral-caudal course of the vidian canal was medial to lateral and was followed by the straight course, tortuous course, and lateral-to-medial course. The frequency of pneumatization pattern from most common to least common was types 0, III, II and I. Of 342 evaluated sides, the vidian canal was located below the level of the anterior genu of petrous ICA in 303 (89%) sides, at same level with the anterior genu of petrous ICA in twenty-five(7%) sides, and above the level of the anterior genu of petrous ICA in fourteen(4.1%) sides.

CONCLUSIONS

A variety of previously undefined features of the vidian canal that can alter the course of surgical procedure were defined. The position of the vidian canal with respect to the petrous internal carotid artery (ICA) was extensively described. From a surgical standpoint, a working room inferior and medial to the vidian canal might not always be a safe approach, because the vidian canal could be located superior to the level of the anterior genu of petrous ICA according to our findings in the present study.

Full-endoscopic uniportal retropharyngeal odontoidectomy for anterior craniocervical infection

BACKGROUND

Infections of the anterior craniocervical junction may require surgery. There are various techniques with individual advantages and disadvantages. This study evaluates the full-endoscopic uniportal technique via the anterior retropharyngeal approach for odontoidectomy, decompression, and debridement.

MATERIAL AND METHODS

Three patients with an infection of the anterior craniocervical junction with retrodental involvement were operated on between 2014 and 2016 using the full-endoscopic uniportal technique. Posterior stabilization was also performed with the same procedure for all patients.

RESULTS

The operation was technically satisfactory in all cases. No problems due to swelling of the pharyngeal soft tissue occurred. No other complications were observed. All patients had a satisfactory outcome with stable regression of the myelopathy symptoms and/or complete healing of the infection. The follow-up images showed sufficient decompression of bone and soft tissues in all cases.

CONCLUSIONS

The full-endoscopic uniportal technique with an anterior retropharyngeal approach can be an adequate and minimally invasive surgical technique for odontoidectomy, decompression, and debridement in infections of the craniocervical junction and can reduce access-related problems. The transoral, transnasal, and retropharyngeal approaches have different surgical fields due to the access trajectories, which must be taken into consideration depending on the anatomy and pathology when selecting a suitable technique.

Full-endoscopic Uniportal Odontoidectomy and Decompression of the Anterior Cervicomedullary Junction Using the Retropharyngeal Approach

STUDY DESIGN

A study of a series of consecutive full-endoscopic uniportal decompressions of the anterior craniocervical junction with retropharyngeal approach.

OBJECTIVE

The aim of this study was to evaluate the direct anterior decompression of the craniocervical junction in patients with bulbomedullary compression using a full-endoscopic uniportal technique via an anterolateral retropharyngeal approach.

SUMMARY OF BACKGROUND DATA

Acute or progressive myelopathy may necessitate direct anterior decompression of the craniocervical junction and odontoidectomy. Different techniques with individual advantages and disadvantages can be used. In addition to the gold standard - the transoral approach - there is increasing experience with the endoscopic transnasal technique. Other alternative procedures are also being developed.

METHODS

Between 2013 and 2016, eight patients with basilar impression, retrodental pannus, or retrodental infection were operated in the full-endoscopic uniportal technique with a retropharyngeal approach. Anterior decompression of the bulbomedullary junction with odontoidectomy was performed. All patients additionally underwent posterior stabilization. Imaging and clinical data were collected in follow-up examinations for 1 year.

RESULTS

The bulbomedullary junction was adequately decompressed. No problems due to swelling of pharyngeal soft tissue occurred. One patient required revision due to secondary bleeding. No other complications were observed. All patients had a good clinical outcome with stable regression of the myelopathy symptoms and/or healing of the infection. The imaging follow-up showed sufficient decompression of bone and soft tissue in all cases. No evidence was found of increasing instability or failure of posterior fusion.

CONCLUSION

In the operated patients, the full-endoscopic uniportal surgical technique with anterior retropharyngeal approach was found to be a sufficient and minimally invasive method with the known advantages of an endoscopic procedure under continuous irrigation. It should not be viewed only as competition for other surgical techniques - due to its individual technical parameters, it can also be considered to be an alternative or complementary procedure.

LEVEL OF EVIDENCE

4.

Surgical Management of Tumors Involving Meckel's Cave and Cavernous Sinus: Role of an Extended Middle Fossa and Lateral Sphenoidectomy Approach

OBJECTIVE

To study the indications and outcomes of lateral sphenoidectomy as part of a combined skull base approach in the treatment of tumors involving Meckel's cave (MC) and cavernous sinus (CS).

STUDY DESIGN

Retrospective patient series.

SETTING

Tertiary referral center.

PATIENTS

Twenty-two consecutive patients (mean age: 45 yr, range: 16-76) who underwent transzygomatic, extended middle fossa approaches for tumors involving MC and CS.

INTERVENTIONS

Surgical access to MC and CS was achieved via extended middle fossa, trans-clinoid approach. Lateral sphenoidectomy was defined as drill-out of the greater sphenoid wing lateral to foramen rotundum and ovale, decompression of superior orbital fissure, and removal of anterior clinoid process. Reconstruction was achieved using combination of autologous and synthetic materials. Eleven patients (50%) received adjuvant radiation.

MAIN OUTCOME MEASURES AND RESULTS

Tumor pathologies included meningioma (16 patients), epidermoid cyst (2), trigeminal schwannoma (2), invasive pituitary adenoma (1), and chondrosarcoma (1). Mean (range) preoperative tumor size was 4.0 cm (1.3-9). Mean (range) length of follow-up was 4 years (range 0.1-10). Overall tumor control and gross total resection were achieved in 95 and 23% of patients, respectively. Lateral sphenoidectomy was performed in 16 patients (73%) for enhanced surgical access and/or tumor extension to the infratemporal fossa (6 patients). Postoperatively, cranial nerve deficits occurred in 12 (55%) patients (V-9 patients; III, IV, or VI-4; VII-2; VIII-2). Cerebrospinal fluid leak and hydrocephalus occurred in two and four patients, respectively.

CONCLUSION

In combination with middle fossa-based approaches to tumors involving MC and CS, lateral sphenoidectomy may play a viable role in tumor access and control.

Walk the Line. The Surgical Highways to the Craniovertebral Junction in Endoscopic Approaches: A Historical Perspective

BACKGROUND

We compiled a comprehensive literature review on the anatomic and clinical results of endoscopic approaches to the craniocervical junction (CVJ) to better contribute to identify the best strategy.

METHODS

An updated literature review was performed in the PubMed, OVID, and Google Scholar medical databases, using the terms "Craniovertebral junction," "Transoral approach," "Transnasal approach," "Transcervical approach," "Endoscopic endonasal approach," "Endoscopic transoral approach," "Endoscopic transcervical approach." Clinical series, anatomic studies, and comparative studies were reviewed.

RESULTS

Pure endonasal and cervical endoscopic approaches still have some disadvantages, including the learning curve and the deeper surgical field. Endoscopically assisted transoral surgery with 30° endoscopes represents an emerging option to standard microsurgical techniques for transoral approaches to the anterior CVJ. This approach should be considered as complementary rather than an alternative to the traditional microsurgical transoral-transpharyngeal approach.

CONCLUSIONS

The transoral approach with sparing of the soft palate still remains the gold standard compared with the pure transnasal and transcervical approaches because of the wider working channel provided by the former technique. The transnasal endoscopic approach alone appears to be superior when the CVJ lesion exceeds the upper limit of the inferior third of the clivus.

Extraneuraxial Hemangioblastoma: Clinicopathologic Features and Review of the Literature

Extraneuraxial hemangioblastoma occurs in nervous paraneuraxial structures, somatic tissues, and visceral organs, as part of von Hippel-Lindau disease (VHLD) or in sporadic cases. The VHL gene plausibly plays a key role in the initiation and tumorigenesis of both central nervous system and extraneuraxial hemangioblastoma, therefore, the underlying molecular and genetic mechanisms of the tumor growth are initially reviewed. The clinical criteria for the diagnosis of VHLD are summarized, with emphasis on the distinction of sporadic hemangioblastoma from the form fruste of VHLD (eg, hemangioblastoma-only VHLD). The world literature on the topic of extraneuraxial hemangioblastomas has been comprehensively reviewed with ∼200 cases reported to date: up to 140 paraneuraxial, mostly of proximal spinal nerve roots, and 65 peripheral, 15 of soft tissue, 6 peripheral nerve, 5 bone, and 39 of internal viscera, including 26 renal and 13 nonrenal. A handful of possible yet uncertain cases from older literature are not included in this review. The clinicopathologic features of extraneuraxial hemangioblastoma are selectively presented by anatomic site of origin, and the differential diagnosis is emphasized in these subsets. Reference is made also to 10 of the authors' personal cases of extraneuraxial hemangioblastomas, which include 4 paraneuraxial and 6 peripheral (2 soft tissue hemangioblastoma and 4 renal).

Suprasellar Hemangioblastoma with Reversible Edema-Like Change Along the Optic Tract: A Case Report and Literature Review

BACKGROUND

Hemangioblastomas usually occur in the cerebellum and are often a component of von Hippel-Lindau disease. Edema-like changes along the optic tract are commonly observed in association with tumors in the sellar and suprasellar regions, such as craniopharyngiomas and pituitary adenomas. Here, we describe a case of sporadic suprasellar hemangioblastoma with edema-like changes along the optic tract that completely resolved after surgery.

CASE DESCRIPTION

The patient was a 28-year-old woman with failing vision and a bitemporal hemianopia. Magnetic resonance imaging revealed a tumor accompanied by a 10-mm cyst. Fluid-attenuated inversion recovery axial magnetic resonance imaging revealed a hyperintense region along the optic tract. Other regions of the central nervous system were normal. Endoscopic transsphenoidal surgery was performed, and the histopathologic findings confirmed hemangioblastoma. Six months after surgery, the edema-like change along the optic tract had disappeared. The patient is doing well without pituitary insufficiency, pituitary hormone medications, or signs of tumor recurrence. In addition, the genetic test was negative for von Hippel-Lindau mutations.

CONCLUSIONS

When examining a patient with suprasellar tumor, clinicians must consider the possibility of hemangioblastoma. Adequate treatment can improve the edematous change and visual disturbance.

Surgical approach for suprasellar hemangioblastomas preserving the pituitary stalk: Review of the literature and report of a further case

Hemangioblastomas (HBLs) are challenging vascular tumours with rare suprasellar location Surgery is recommended in patients with visual impairment, endocrine disorders or hydrocephalus. Surgical removal of pituitary stalk HBLs is challenging due to their location and high vascularity. Our narrative review was guided by the question: "what is the more suitable surgical approach to excise a suprasellar HBL?". Pertinent English literature was scrutinized from database inception to October 2016. Eighteen articles matched our selection criteria. Among the surgically treated patients, 4 were treated through a trans-sphenoidal (TS) approach, 13 through a transcranial approach (2 of them after TS failure). Five other cases were treated with radiotherapy (adjuvant in 3 cases) and 9 patients were managed with simple observation and/or medical treatment. We add a case of complete suprasellar HBL resection through an orbito-zygomatic (OZ) craniotomy with extradural anterior clinoidectomy (EAC). To achieve satisfactory oncologic results with acceptable morbidity for symptomatic suprasellar HBLs, complete tumour removal with pituitary stalk sparing should be attempted through an OZ craniotomy with EAC that provides adequate exposure of the tumour, its vascular supply and the adjacent neural structures.

Tumor Volume Decrease via Feeder Occlusion for Treating a Large, Firm Trigone Meningioma

Trigone meningiomas are considered a surgical challenge, as they tend to be considerably large and hypervascularized at the time of presentation. We experienced a case of a large and very hard trigone meningioma that was effectively treated using initial microsurgical feeder occlusion followed by surgery in stages. A 19-year-old woman who presented with loss of consciousness was referred to our hospital for surgical treatment of a brain tumor. Radiological findings were compatible with a left ventricular trigone meningioma extending laterally in proximity to the Sylvian fissure. At initial surgery using the transsylvian approach, main feeders originating from the anterior and lateral posterior choroidal arteries were occluded at the inferior horn; however, only a small section of the tumor could initially be removed because of its firmness. Over time, feeder occlusion resulted in tumor necrosis and a 20% decrease in its diameter; the mass effect was alleviated within 1 year. The residual meningioma was then totally excised in staged surgical procedures after resection became more feasible owing to ischemia-induced partial softening of the tumor. When a trigone meningioma is large and very hard, initial microsurgical feeder occlusion in the inferior horn can be a safe and effective option, and can lead to necrosis, volume decrease, and partial softening of the residual tumor to allow for its staged surgical excision.

Pituitary Adenoma Associated With Rathke’s Cleft Cyst: Report of 15 Cases

Objective: The concomitant presence of pituitary adenoma (PA) with Rathke’s cleft cyst (RCC) is rare, and most of the literature published is case reports. RCC’s clinicopathological features have not been well described. Methods: We retrospectively reviewed the data of 15 patients with PA associated with RCC. We also provide a systematic review of the literature. Results: The patients included males and seven females. The transsphenoidal approach was adopted for all patients except one, who underwent right frontal craniotomy. Complete resection was achieved in nine cases, with grossly complete resection in five and partial removal in one. Of the PA subtypes available, five patients had nonfunctional pituitary adenomas, three had multiple-hormone secreting PAs, three had prolactin-producing adenomas, and one had a growth hormone-secreting adenoma. All of the patients’ symptoms and abnormal endocrine test results resolved or were relieved after surgery. The mean follow-up time was 27.6±16.6 months. All of the patients recovered well and had no signs of recurrence during their follow-up, except for one patient. Conclusions: A cyst-like signal indicated on images or cystic materials encountered during operation in a patient with PA suggest the possibility of PA associated with RCC. Transsphenoidal surgery is the preferred approach and can resolve or relieve patients’ symptoms to a great extent. Histologically, nonfunctional PA and prolactinoma are the most common types of PA coexisting with RCC; the mechanisms of PA associated with RCC need to be investigated further.

The endoscopic endonasal approach to cranio-cervical junction: the complete panel

We aim to establish a complete summary on the Endoscopic Endonasal Approach (EEA) to Cranio Cervical Junction (CCJ): evolution since first description, criteria to predict the feasibility and limitations, anatomical landmarks, indications and biomechanical evaluation after performing the approach. A comprehensive literature search to identify all available literature published between March 2002 and June 2015, the articles were divided into four categories according to their main purpose: 1- surgical technique, 2- anatomical landmarks and limitations, 3- literature reviews to identify main indications, 4- biomechanical studies. Thereafter, we demonstrate the approach step-by-step, using 1 fresh and 3 silicon injected embalmed cadaveric specimen heads. 61 articles and one poster were identified. The approach was first described on cadaveric study in 2002, and firstly used to perform odontoidectomy in 2005. The main indication is odontoid rheumatoid pannus and basilar invagination. The nasopalatine line (NPL), the superior nostril-hard palate Line (SN-HP), the naso-axial line (NAxL), the rhinopalatine Line (RPL) and other methods were described to predict the anatomical feasibility of the approach. The craniocervical fusion is potentially unnecessary after removal of < 75% of one occipital condyle. A recent cadaveric study stated the possibility of C1-C2 fusion via EEA. This paper reviews all available clinical and anatomical studies on the EEA to CCJ. The approach marked a significant evolution since its first description in 2002. Because of its lesser complications compared to the transoral approach, the EEA became when feasible, the approach of choice to the ventral CCJ.

Dermoid Cyst of the Prepontine Cistern and Meckel's Cave: Illustrative Case and Systematic Review

Objective  Dermoid cysts are benign, congenital malformations that account for ∼0.5% of intracranial neoplasms. The authors describe a 42-year-old female with a prepontine dermoid cyst who underwent apparent gross total resection (GTR) but experienced cyst recurrence. To date, very few cases of prepontine dermoid cysts have been reported. The prevalent region where these cysts are located can be difficult to determine. In addition, the authors systematically review the literature to characterize the clinical presentation, anatomical distribution, and surgical outcomes of intracranial dermoid cysts. Design  Systematic review. Setting/Participants  PubMed, Web of Science, and Scopus databases. Main Outcome Measures  Extent of resection, symptom improvement, and recurrence rates. Results  A total of 69 patients with intracranial dermoid cysts were identified. Three (4.3%) intracranial dermoid cysts were located in the prepontine cistern. The average age of patients was 33.3 years. The most common presenting symptoms were headache (52.2%) and visual disturbances (33.3%). Intracranial dermoid cysts were distributed similarly throughout the anterior, middle, and posterior cranial fossae (29.0%, 36.2%, and 29.0%, respectively). GTR was achieved in 42.0% of cases. Thirty-four (49.3%) patients experienced symptom resolution. Recurrence rate was 5.8% at a mean follow-up of 2.1 years. Conclusions  Intracranial dermoid cysts most often present as headaches and visual disturbances. Intracranial dermoid cysts were found in the anterior, middle, and posterior cranial fossae at similar frequencies but with clear predilections for the Sylvian fissure, sellar region, and cerebellar vermis. Outcomes following surgical excision of intracranial dermoid cysts are generally favorable despite moderate rates of GTR.

Endoscopic Endonasal Approach for Craniovertebral Junction Pathologic Conditions: Myth and Truth in Clinical Series and Personal Experience

OBJECTIVE

For many years, the microsurgical transoral approach has been accepted as the gold standard for anterior decompressions of the craniovertebral junction (CVJ). The introduction of the endoscopic endonasal approach (EEA) has gained wide recognition and overwhelming support in recent years, including for diseases of the CVJ. The aim of this study was to critically analyze and discuss all cases of CVJ diseases approached by means of an EEA so far reported in the literature, including our institutional experience consisting of 6 consecutive patients.

METHODS

Six consecutive patients affected by CVJ disease underwent an EEA. Three patients had a tumor (2 chordomas and 1 myeloma) and 3 had impressio basilaris.

RESULTS

Five patients had an uncomplicated postoperative course and 1 developed an intraoperative cerebrospinal fluid leak and subsequent meningitis and died 5 weeks after surgery. A total of 107 patients (including our 6) affected by CVJ disease and treated with EEA have been reported so far. Among these patients, cerebrospinal fluid leak was reported in 13 (12.4%), transient velopharyngeal incompetence in 6 (5.6%), postoperative epistaxis in 2 (1.86%), and respiratory dysfunction requiring a tracheostomy in 2 (1.86%). In our extended institutional series of more than 20 consecutive anterior decompressions for CVJ diseases (including transoral and transnasal microsurgical approaches), the only fatal complication was associated with EEA.

CONCLUSIONS

On the basis of the reviewed literature and our personal experience, the reported increased safety of the EEA needs to be reassessed and discussed.

Image-guided transoral approach in severe craniovertebral junction malformations at the golden age of endoscopy: Regarding 2 cases

INTRODUCTION

The image-guided transoral approach (IGTOA) provides a safe exposure to skull base midline lesions and the ventral aspect of the craniovertebral junction (CVJ). The IGTOA has several advantages: the head being placed in the extended position, it decreases the brainstem angulation during surgery; the approach being done through the avascular median pharyngeal raphe, not only lowers the bleeding risk but also provides a direct access to the bony pathology and granulation tissue accessible only via the ventral route. Wide field exposure and maneuverability are necessary to deal with the entire ventral brainstem compression in case of severe CVJ malformation to safely perform partial clivectomy and odontoidectomy.

PRESENTATION OF TWO CASES

We illustrate the cases of two patients, 52-year-old and 42-year-old males, who presented with an impressive craniovertebral junction malformation, confirmed on CT and MRI images. They first underwent surgery by IGTOA, later completed by occipitocervical fixation. For the two patients, outcomes were assessed respectively at 4 and 5 years and showed satisfactory results both clinically and radiologically.

CONCLUSION

In patients with marked ventral compression, the IGTOA provides direct and guided access to the anterior aspect of the CVJ and effective means for odontoidectomy and clivectomy. This approach is more easily maneuverable compared to the endonasal endoscopic approach. The IGTOA approach is quite a complex technique, requiring multidisciplinary skills, but it should primarily be used in difficult situations. We suggest that endonasal endoscopy is over-utilized. We consider that endoscopy should not be routinely performed and kept only for well-selected cases.

Endoscopic Transnasal Odontoidectomy

Transoral microscopic odontoidectomy followed by posterior fixation has been accepted as a standard procedure to treat nonreducible basilar invagination during the half past century. In recent years, the development of endoscopic techniques has raised challenges regarding the traditional treatment algorithm. The endoscopic transnasal odontoidectomy is a feasible and effective method in the treatment of irreducible ventral cervicomedullary junction compression, which has several advantages over the transoral approach. The endoscopic odontoidectomy includes transnasal, transoral, and transcervical approaches. The 3 different approaches for endoscopic odontoidectomy present complementary advantages and limitations. The necessity of posterior fixation after odontoidectomy should be considered in every single case on the basis of the peculiar anatomic and clinical conditions.

Selection of surgical procedures for basilar invagination with atlantoaxial dislocation

BACKGROUND CONTEXT

Basilar invagination (BI) is a malformation of craniovertebral junction. However, surgical procedures on BI with atlantoaxial dislocation (AAD) remain controversial.

PURPOSE

This research aimed to investigate the selection of surgical procedures and its significance in the surgical treatment of patients with BI and AAD.

STUDY DESIGN

This was a retrospective study.

PATIENT SAMPLE

This study enrolled 33 patients who were diagnosed with BI and AAD and were followed up for at least 6 months.

OUTCOME MEASURE

All of the patients were assessed for neurologic recovery observation in terms of Japanese Orthopaedic Association scores and Odom criteria. X-ray, magnetic resonance imaging, or computed tomography scanning was used to determine reduction, compression, bone graft, and internal fixation before and after operation.

METHODS

Thirty-three patients who suffered from BI with AAD were treated in our department from July 2000 to October 2014. Preoperatively, the patients were divided into two types on the basis of whether dislocation was reduced after anesthesia and traction were performed: reducible dislocation (Type A) and irreducible dislocation (Type B). Reducible dislocation was further divided into two subtypes: full reducible dislocation (Type A1) and partial reducible dislocation (Type A2). Type A1 patients were treated with direct posterior fixation and fusion after traction and reduction. Type A2 patients received posterior atlantoaxial release, fixation, and fusion under traction. Type B patients underwent transoral atlantoaxial release, posterior fixation, and fusion.

RESULTS

There were 5 Type A1 patients, 10 Type A2 patients, and 18 Type B patients treated in accordance with the proposed scheme. Postoperatively, sufficient reduction and decompression were achieved for all cases. Two Type B patients died. Other patients were followed up from 6 months to 42 months (average=16.6 months); follow-up results showed sufficient decompression, effective fixation and fusion, and no reduction loss. The Japanese Orthopaedic Association Score increased from preoperative 4-12 (average, 7.8) to postoperative 10-17 (average, 14.3), and neurologic recovery was satisfactory.

CONCLUSIONS

Under traction, simple posterior fixation and fusion were effective for Type A patients suffering from BI with AAD; anterior atlantoaxial release and posterior fixation and fusion were effective for Type B patients with BI and AAD.

Endoscopic Approaches to the Craniovertebral Junction

The endoscopic endonasal approach provides a direct surgical trajectory to anteriorly located lesions at the craniovertebral junction. The inferior limit of surgical exposure is predicted by the nasopalatine line, and the lateral limit is demarcated by the lower cranial nerves. Endoscopic endonasal odontoidectomy allows preservation of the soft palate, and patients can restart an oral diet on the first postoperative day. Treating the condition at the craniovertebral junction using this approach requires careful preoperative planning and endoscopic endonasal surgical experience with a 2-surgeon 4-handed approach combining expertise in otolaryngology and neurosurgery.

Transoral and transnasal odontoidectomy complications: A systematic review and meta-analysis

OBJECT

The craniovertebral junction (CVJ) is a complex region of the spine with unique anatomical and functional relationships. To alleviate symptoms associated with pathological processes involving the odontoid process, decompression is often required, including odontoidectomy. Accurate knowledge of the complication rates following the transoral and transnasal techniques is essential for both patients and surgeons.

METHODS

We conducted MEDLINE, Scopus and Web of Science database searches for studies reporting complications associated with the transoral and transnasal techniques for odontoidectomy. Case series presenting data for less than three patients were excluded. Rates of complication and clinical outcomes were calculated and subsequently analyzed using a fixed-effects model to assess statistical significance.

RESULTS

Of 1288 articles retrieved from MEDLINE, Scopus, and Web of Science, twenty-six met inclusion criteria. Transoral and transnasal procedures resulted in the following respective complication rates: arterial injury 1.9% and 0.0%, intraoperative CSF leak 0.3% and 30.0%, postoperative CSF leak 0.8% and 5.2%, 30-day mortality 2.9% and 4.4%, medical complications 13.9% and 28.6%, meningitis 1.0% and 4.0%, pharyngeal wound dehiscence 1.7% (transnasal not reported), pneumonia 10.3% (transnasal not reported), prolonged or re-intubation 5.6% and 6.0%, reoperation 2.5% and 5.1%, sepsis 1.9% and 7.7%, tracheostomy 10.8% and 3.4%, velopharyngeal insufficiency 3.3% and 6.4% and wound infection 3.3% and 1.9%. None of these differences were statistically significant, except for postoperative tracheostomy, which was significantly higher after transoral odontoidectomy 8.4% (95% CI 4.9% -11.9%) compared to transnasal odontoidectomy 0.8% (95% CI -1.0% -2.9%). Neurologic outcome was improved in 90.0% and worse in 0.9% of patients after transoral compared to 94.0% and 0.0% after transnasal odontoidectomy (p=0.30).

CONCLUSIONS

This work presents a systematic review of complications reported for transoral or transnasal odontoidectomy across a heterogeneous group of surgeons and patients. Due to inconsistent reporting, statistical significance was only achieved for postoperative tracheostomy, which was significantly higher in the transoral group. This investigation sets the framework for further discussions regarding odontoidectomy approach options and their associated complications during the informed consent process.

Treatment Outcomes of Rathke's Cleft Cysts Managed with Marsupialization

Objectives Rathke's cleft cysts (RCC) are benign cystic lesions of the sella resulting from incomplete obliteration of Rathke's cleft. Symptomatic lesions often require surgical decompression, which is often amenable to a transnasal, transsphenoidal (TNTS) approach. We report our experience with marsupialization of RCC and describe a novel technique to promote re-epithelization of the cyst cavity. Design Retrospective review. Setting Tertiary academic medical center. Participants Patients who underwent TNTS for RCC between 2007 and 2015. Main Outcome Measures Demographics, lesion characteristics, and reconstruction and treatment outcomes. Results In total, 52 patients were identified. The mean age was 41 ± 18 years. The mean RCC size was 13 ± 5 mm. Intraoperative cerebrospinal fluid (CSF) leak was encountered in 14 (27%) patients; all were repaired. There were six complications (12%) and no deaths. Mean follow-up was 20 ± 18 months, with five (10%) recurrences. RCC size was associated with intraoperative CSF leak (p = 0.04). In 12 patients, the marsupialized cyst cavity was lined with a free mucosal graft (FMG) to promote healing and re-epithelialization. Conclusions The TNTS approach is safe and effective in surgical decompression of RCC. Lining the exposed cyst cavity with an FMG is a simple intervention without added morbidity that may promote formation of an epithelialized tract. Level of Evidence Not applicable.

The white matter tracts of the cerebrum in ventricular surgery and hydrocephalus

OBJECTIVE The relationship of the white matter tracts to the lateral ventricles is important when planning surgical approaches to the ventricles and in understanding the symptoms of hydrocephalus. The authors' aim was to explore the relationship of the white matter tracts of the cerebrum to the lateral ventricles using fiber dissection technique and MR tractography and to discuss these findings in relation to approaches to ventricular lesions. METHODS Forty adult human formalin-fixed cadaveric hemispheres (20 brains) and 3 whole heads were examined using fiber dissection technique. The dissections were performed from lateral to medial, medial to lateral, superior to inferior, and inferior to superior. MR tractography showing the lateral ventricles aided in the understanding of the 3D relationships of the white matter tracts with the lateral ventricles. RESULTS The relationship between the lateral ventricles and the superior longitudinal I, II, and III, arcuate, vertical occipital, middle longitudinal, inferior longitudinal, inferior frontooccipital, uncinate, sledge runner, and lingular amygdaloidal fasciculi; and the anterior commissure fibers, optic radiations, internal capsule, corona radiata, thalamic radiations, cingulum, corpus callosum, fornix, caudate nucleus, thalamus, stria terminalis, and stria medullaris thalami were defined anatomically and radiologically. These fibers and structures have a consistent relationship to the lateral ventricles. CONCLUSIONS Knowledge of the relationship of the white matter tracts of the cerebrum to the lateral ventricles should aid in planning more accurate surgery for lesions within the lateral ventricles.

Supratentorial haemangioblastoma without von Hippel-Lindau syndrome in an adult: A rare tumor with review of literature

Supratentorial hemangioblastomas (HBLs) are rare, benign vascular tumors of the central nervous system neoplasms. Very scarce literature is available regarding supratentorial HBL without von Hippel–Lindau (VHL) syndrome in an adult. We reviewed the literature and PubMed advanced search showed only a few results of supratentorial HBL without VHL syndrome. We reported a rare case of cystic supratentorial HBL in 39-year-old male affecting the parietal lobe without VHL syndrome. Supratentorial HBL is a rare tumor and supratentorial HBL without VHL syndrome are even rarer. Being a rare entity, not much clinical data is currently available regarding supratentorial HBLs, thus necessitating the need for further reporting and review of such cases.

The endoscopic transoral approach to the craniovertebral junction: an anatomical study with a clinical example

OBJECTIVE

The microscopic transoral, endoscopic transnasal, and endoscopic transoral approaches are used alone and in combination for a variety of craniovertebral junction (CVJ) pathologies. The endoscopic transoral approach provides a more direct exposure that is not restricted by the nasal cavity, pterygoid plates, and palate while sparing the potential morbidities associated with extensive soft-tissue dissection, palatal splitting, or mandibulotomy. Concerns regarding the extent of visualization afforded by the endoscopic transoral approach may be limiting its widespread adoption.

METHODS

A dissection of 10 cadaver heads was undertaken. CT-based imaging guidance was used to measure the working corridor of the endoscopic transoral approach. Measurements were made relative to the palatal line. The built-in linear measurement tool was used to measure the superior and inferior extents of view. The superolateral extent was measured relative to the midline, as defined by the nasal process of the maxilla. The height of the clivus, odontoid tip, and superior aspect of the C-1 arch were also measured relative to the palatal line. A correlated clinical case is presented with video.

RESULTS

The CVJ was accessible in all cases. The superior extent of the approach was a mean 19.08 mm above the palatal line (range 11.1–27.7 mm). The superolateral extent relative to the midline was 15.45 mm on the right side (range 9.6–23.7 mm) and 16.70 mm on the left side (range 8.1–26.7 mm). The inferior extent was a mean 34.58 mm below the palatal line (range 22.2–41.6 mm). The mean distances were as follows: palatal line relative to the odontoid tip, 0.97 mm (range −4.9 to 3.7 mm); palatal line relative to the height of the clivus, 4.88 mm (range −1.5 to 7.3 mm); and palatal line relative to the C-1 arch, −2.75 mm (range −5.8 to 0 mm).

CONCLUSIONS

The endoscopic transoral approach can reliably access the CVJ. This approach avoids the dissections and morbidities associated with a palate-splitting technique (velopharyngeal insufficiency) and the expanded endonasal approach (mucus crusting, sinusitis, and potential lacerum or cavernous-paraclival internal carotid artery injury). For appropriately selected lesions near the palatal line, the endoscopic transoral approach appears to be the preferred approach.

Anatomical study of pterygoid canal (PC) and palatovaginal canal (PVC) in endoscopic trans-sphenoidal approach

PURPOSE

The primary purpose of our work was to make anatomical measurements of pterygoid canal (PC) and palatovaginal canal (PVC). The secondary goal was to locate the two structures based on the landmarks in the trans-sphenoidal surgery and draw a safe corridor of fenestration in the bottom of sphenoid sinus during surgical procedure to sphenopalatine region.

MATERIALS AND METHODS

Computed tomographic angiography (CTA) images of PC, PVC and sphenoid sinus in 200 adults were reviewed. Multiplanar reconstruction of the CT images was performed, and the anatomical features of the PC and PVC were studied in the coronal, sagittal, and axial planes. The length, diameter and direction of PC and PVC were measured in the plane through or perpendicular to them. The anterior and posterior opening of PC and PVC were identified by the surgical landmarks such as the middle lowest point of sellar floor, the sagittal midline and the bottom of the sphenoid sinus.

RESULT

Both PC and PVC can be found and identified easily on CTA image, the shape and size of the PC and PVC were in agreement with those retrieved from previous literatures, the position of them can be located by the anatomical landmarks in sphenoid sinus.

CONCLUSION

Knowing the anatomical features of PC and PVC and their location based on the anatomical landmarks are helpful to the endoscopic trans-sphenoidal surgery. These data in our study will provide surgeons a better understanding of PC and PVC and their relationship to sphenoid sinus. Notably, it will not help the surgeons to avoid injuring neurovascular structures as well as provided supportive information for the choice of the appropriate endoscopic equipment.

Endoscopic endonasal approach for craniovertebral junction pathology: a review of the literature

OBJECT

The transoral approach is the gold standard for ventral decompression of the brainstem caused by craniovertebral junction (CVJ) pathology. This approach is often associated with significant morbidity, related to swallowing and respiratory complications. The endoscopic endonasal approach was introduced to reduce the rate of these complications. However, the exact role of this approach in the treatment of CVJ pathology is not well defined.

METHODS

A comprehensive literature search was performed to identify series of patients with pathology of the CVJ treated via the endoscopie endonasal approach. Data on patient characteristics, indications for treatment, complications, and outcome were obtained and analyzed.

RESULTS

Twelve studies involving 72 patients were included. The most common indications for treatment were rheumatoid pannus (38.9%) and basilar invagination (29.2%). Cerebrospinal fluid leak was found in 18% of cases intraoperatively and 4.2% of cases postoperatively. One case of meningitis complicated by sepsis and death represents the procedure-related mortality of 1.4%. Of the patients without preoperative swallowing impairment, 95% returned to oral feeding on the 3rd postoperative day. Ninety-three percent of patients experienced improvement in neurological symptoms after the procedure.

CONCLUSIONS

The endonasal endoscopie approach is effective for the treatment of neural compression caused by CVJ pathology. It offers advantages such as lower rates of postoperative dysphagia and respiratory complications when compared with the more traditional transoral approach. However, these 2 approaches should be seen as complementary rather than alternatives. Patient-related factors as well as the surgeon's expertise must be considered when making treatment decisions.

Endoscopic endonasal transclival transodontoid approach for ventral decompression of the craniovertebral junction: operative technique and nuances

The transoral approach is considered the gold-standard surgical route for performing anterior odontoidectomy and ventral decompression of the craniovertebral junction for pathological conditions that result in symptomatic cervicomedullary compression, including basilar invagination, rheumatoid pannus, platybasia with retroflexed odontoid processes, and neoplasms. Extended modifications to increase the operative corridor and exposure include the transmaxillary, extended "open-door" maxillotomy, transpalatal, and transmandibular approaches. With the advent of extended endoscopic endonasal skull base techniques, there has been increased interest in the last decade in the endoscopic endonasal transclival transodontoid approach to the craniovertebral junction. The endonasal route represents an attractive minimally invasive surgical alternative, especially in cases of irreducible basilar invagination in which the pathology is situated well above the palatine line. Angled endoscopes and instrumentation can also be used for lower-lying pathology. By avoiding the oral cavity and subsequently using a transoral retractor, the endonasal route has the advantages of avoiding complications related to tongue swelling, tracheal swelling, prolonged intubation, velopharyngeal insufficiency, dysphagia, and dysphonia. Postoperative recovery is quicker, and hospital stays are shorter. In this report, the authors describe and illustrate their method of purely endoscopic endonasal transclival odonotoidectomy for anterior decompression of the craniovertebral junction and describe various operative pearls and nuances of the technique for avoiding complications.

Intraventricular Meningioma: Technical Nuances in Surgical Management

OBJECTIVE

Intraventricular meningiomas (IVMs) are rare tumors compared with intracranial meningiomas. Optimal surgical management of IVMs is controversial. The objective of this article was to review the outcomes and complications of meningiomas treated with various surgical approaches.

METHODS

We performed a retrospective review of 18 patients with IVMs who received different treatment strategies during the period 2000-2014. Of 18 patients, 17 underwent microsurgical resection, and 1 patient received Gamma Knife radiosurgery. The literature was reviewed to compare the present cohort with previously published series.

RESULTS

In our series, 12 (70%) patients underwent parieto-occipital craniotomy and a superior parietal gyrus approach, which was similar to procedures used in various series (74.4%) in the existing literature. Preoperatively, patients commonly presented with headache (65%) and neurologic deficits (70%). After surgical management, there was a significant reduction in symptoms, including headache (preoperative 65% vs. postoperative 6%, P = 0.0001), and neurologic deficits (preoperative 70% vs. postoperative 5.5%). Preoperatively, 2 patients experienced visual impairment, which was completely resolved after surgery. The Karnofsky performance scale was significantly improved after resection compared with before treatment (89 vs. 76, P = 0.003). In 4 patients with World Health Organization grade II tumor, redo surgery was required because of recurrence of tumor.

CONCLUSIONS

Based on a literature review and our experience, surgical approaches for patients with IVM vary according to size, location, and laterality of the meningioma. In addition, the growth pattern of the tumor (transependymal extension), vascular supply of the tumor, and brain function (particularly visual function) can affect surgical treatment and should be identified preoperatively.

Endoscopic Endonasal Approach in the Management of Rathke's Cleft Cysts

OBJECTIVE

Rathke's cleft cysts (RCCs) are quite uncommon sellar lesions that can extend or even arise in the suprasellar area. The purpose of this study is to evaluate the effectiveness of both standard and extended endoscopic endonasal approaches in the management of different located RCCs.

METHODS

We retrospectively analyzed a series of 29 patients (9 males, 20 females) complaining of a RCC, who underwent a standard or an extended endoscopic transsphenoidal approach at the Division of Neurosurgery, Department of Neurosciences and Reproductive and Odontostomatological Sciences, of the Università degli Studi di Napoli "Federico II". Data regarding patients' demographics, clinical evaluation, cyst characteristics, surgical treatments, complications and outcomes were extracted from our electronic database (Filemaker Pro 11, File Maker Inc., Santa Clara, California, USA).

RESULTS

A standard transsphenoidal approach was used in 19 cases, while the extended variation of the approach in 10 cases (5 purely suprasellar and 5 intra-suprasellar RCC). Cysts contents was fully drained in all the 29 cases, whilst a gross total removal, that accounts on the complete cyst wall removal, was achieved in an overall 55,1% of patients (16/29), specifically 36,8% (7/19) that received standard approach and 90% (9/10) of those that underwent to extended approach. We reported a 56.2% of recovery from headache, 38.5% of complete recovery and 53.8% of improvement from visual field defect and an overall 46.7% of improvement of the endocrine functions. Postoperative permanent DI rate was 10.3%, overall post-operative CSF leak rate 6.9%; recurrence/regrowth occurred in 4 patients (4/29, 13.8%), but only one required a second surgery.

CONCLUSION

The endoscopic transsphenoidal approach for the removal of a symptomatic RCC offers several advantages in terms of visualization of the surgical field during both the exposure and removal of the lesion. The "extended" variation of the endoscopic approach provides a direct access to the supradiaphragmatic space, allowing adequate view and room for the safe removal of selected supradiaphragmatic RCCs, regardless of the sellar size (even a not enlarged sella), and provides a higher likelihood of preserving normal pituitary tissue and functions.

The contralateral transfalcine transprecuneus approach to the atrium of the lateral ventricle: operative technique and surgical results

BACKGROUND

Surgical approaches to the atrium of the lateral ventricle remain a challenging neurosurgical issue because of the eloquent nature of the surrounding anatomy.

OBJECTIVE

To report our operative techniques and preliminary surgical results with the contralateral transfalcine transprecuneus approach.

METHODS

A retrospective data review was performed of patients undergoing a contralateral transfalcine transprecuneus approach for the resection of lesions in the atrium of the lateral ventricle. Patients were positioned in the prone position with a 30° elevation, and a 15° rotation was used. After a contralateral parasagittal parieto-occipital craniotomy and falx incision, the corticotomy in the contralateral precuneus gyrus created a corridor to the tumor. An endoscope was used to assist with the surgery.

RESULTS

Headache was the primary preoperative symptom, which improved in all patients after surgery. After treatment, symptoms were improved in all 3 patients with hemiparesis and in 3 of 6 patients with preexisting visual deficits; symptoms were unchanged in the other 3 patients with visual deficits during the 13- to 38-month follow-up. Nine lesions were totally removed, and 1 metastatic breast cancer lesion was subtotally removed; all patients had good neurological outcomes and no operative mortality.

CONCLUSION

The contralateral transfalcine transprecuneus approach is appropriate for most lesions in the atrium of the lateral ventricle. It provides a wider surgical angle (especially for the lateral extension) and reduces the risk of disturbance of the optic radiation compared with the conventional approaches. The use of magnetic resonance venography-magnetic resonance imaging neuronavigation makes the procedure much easier and more accurate, and the neuroendoscope adds to the visualization of the microscope and can reduce surgical complications.

Combined endoscopic transnasal and transoral approach for extensive upper cervical osteoradionecrosis

PURPOSE

Osteoradionecrosis (ORN) is a rare yet well-recognized complication following radiotherapy to the head and neck. We illustrate the only case of a spontaneous extrusion of the sequestered C1 arch through the oral cavity and discuss our experience with a combined endoscopic transnasal and transoral approach for cervical ORN.

METHODS

A 56-year-old female presented with a 3-month history of blood-stained nasal discharge. She had been treated with radiotherapy for nasopharyngeal carcinoma 25 years earlier. Flexible nasal endoscopy demonstrated an exposed bone with an edematous posterior nasopharyngeal mass. Computed tomography showed a pre-vertebral mass with destruction of C1 and C2. She underwent occipito-cervical fusion followed by a combined transnasal and transoral endoscopic debridement of non-viable bone in the same perioperative setting. Healing of the raw mucosa was by secondary intention and reconstruction was not performed.

RESULTS

Histopathological examination reported ulcerated inflamed granulation tissue with no evidence of malignancy. During follow-up, she remained neurologically intact with no recurrence.

CONCLUSION

Using both nasal and oral spaces allows placement of the endoscope in the nasal cavity and surgical instruments in the oral cavity without splitting the palate. Hence, the endoscopic transnasal and transoral approach has vast potential to be effective in carefully selected cases of cervical ORN.

The odontoid process invagination in normal subjects, Chiari malformation and Basilar invagination patients: Pathophysiologic correlations with angular craniometry

Background:

Craniometric studies have shown that both Chiari malformation (CM) and basilar invagination (BI) belong to a spectrum of malformations. A more precise method to differentiate between these types of CVJM is desirable. The Chamberlain's line violation (CLV) is the most common method to identify BI. The authors sought to clarify the real importance of CLV in the spectrum of craniovertebral junction malformations (CVJM) and to identify possible pathophysiological relationships.

Methods:

We evaluated the CLV in a sample of CVJM, BI, CM patients and a control group of normal subjects and correlated their data with craniocervical angular craniometry.

Results:

A total of 97 subjects were studied: 32 normal subjects, 41 CM patients, 9 basilar invagination type 1 (BI1) patients, and 15 basilar invagination type 2 (BI2) patients. The mean CLV violation in the groups were: The control group, 0.16 ± 0.45 cm; the CM group, 0.32 ± 0.48 cm; the BI1 group, 1.35 ± 0.5 cm; and the BI2 group, 1.98 ± 0.18 cm. There was strong correlation between CLV and Boogard's angle (R = 0.82, P = 0.000) and the clivus canal angle (R = 0.7, P = 0.000).

Conclusions:

CM's CLV is discrete and similar to the normal subjects. BI1 and BI2 presented with at least of 0.95 cm CLV and these violations were strongly correlated with a primary cranial angulation (clivus horizontalization) and an acute clivus canal angle (a secondary craniocervical angle).

Endoscopic Endonasal Approaches to the Craniovertebral Junction: A Systematic Review of the Literature

Background We reviewed the current literature pertaining to extended endoscopic endonasal approaches to the craniovertebral junction. Methods A systematic literature review was utilized to identify published surgical cases of endoscopic endonasal approaches to the craniovertebral junction. Full-text manuscripts were examined for various measures of surgical indications, patient characteristics, operative technique, and surgical outcomes. Results We identified 71 cases involving endoscopic endonasal approaches for surgical management of a variety of pathologies located within the craniovertebral junction. Patient ages ranged from 3 to 87 years, with 40 females and 31 males. Five patients required tracheostomy, two were reintubated, and all others experienced an average intubation duration of 0.54 days following surgery. Fifty-eight patients (81.7%) underwent an additional posterior decompression or fusion either before or after the endonasal procedure. A complete resection of the pathologic lesion was reported in 57 cases (83.8%), another five were successful biopsies, and four resulted in partial resection. The follow-up time ranged from 0.5 to 57 months. Conclusion Although the transoral approach has been the standard for anterior surgical management for the past several decades, our systematic review illustrates that the extended endoscopic endonasal approach is a safe and effective alternative for most pathologies affecting the craniovertebral junction.

Transnasal odontoid resection: is there an anatomic explanation for differing swallowing outcomes?

OBJECT

Swallowing dysfunction is common following transoral (TO) odontoidectomy. Preliminary experience with newer endoscopic transnasal (TN) approaches suggests that dysphagia may be reduced with this alternative. However, the reasons for this are unclear. The authors hypothesized that the TN approach results in less disruption of the pharyngeal plexus and anatomical structures associated with swallowing. The authors investigate the histological and gross surgical anatomical relationship between pharyngeal plexus innervation of the upper aerodigestive tract and the surgical approaches used (TN and TO). They also review the TN literature to evaluate swallowing outcomes following this approach.

METHODS

Seven cadaveric specimens were used for histological (n = 3) and gross anatomical (n = 4) examination of the pharyngeal plexus with the TO and TN surgical approaches. Particular attention was given to identifying the location of cranial nerves (CNs) IX and X and the sympathetic chain and their contributions to the pharyngeal plexus. S100 staining was performed to assess for the presence of neural tissue in proximity to the midline, and fiber density counts were performed within 1 cm of midline. The relationship between the pharyngeal plexus, clivus, and upper cervical spine (C1-3) was defined.

RESULTS

Histological analysis revealed the presence of pharyngeal plexus fibers in the midline and a significant reduction in paramedian fiber density from C-2 to the lower clivus (p < 0.001). None of these paramedian fibers, however, could be visualized with gross inspection or layer-by-layer dissection. Laterally based primary pharyngeal plexus nerves were identified by tracing their origins from CNs IX and X and the sympathetic chain at the skull base and following them to the pharyngeal musculature. In addition, the authors found 15 studies presenting 52 patients undergoing TN odontoidectomy. Of these patients, only 48 had been swallowing preoperatively. When looking only at this population, 83% (40 of 48) were swallowing by Day 3 and 92% (44 of 48) were swallowing by Day 7.

CONCLUSIONS

Despite the midline approach, both TO and TN approaches may injure a portion of the pharyngeal plexus. By limiting the TN incision to above the palatal plane, the surgeon avoids the high-density neural plexus found in the oropharyngeal wall and limits injury to oropharyngeal musculature involved in swallowing. This may explain the decreased incidence of postoperative dysphagia seen in TN approaches. However, further clinical investigation is warranted.

Suprasellar hemangioblastoma without von Hippel-Lindau disease: a case report and literature review

Suprasellar hemangioblastoma (HBL) without von Hippel-Lindau (VHL) disease is extremely rare. A 51-year-old woman presented with headache and progressively deteriorating bilateral visual disturbance for 4 months. Magnetic resonance imaging (MRI) revealed a 2.5-cm solid mass in the suprasellar region with homogeneous contrast enhancement. Our preoperative presumptive diagnosis was meningioma. Resection of the tumor was achieved via a left pterional craniotomy. The tumor was reddish in appearance and relatively firm, and was extremely vascularized, which might provide extensive blood supply through small branches of the internal carotid artery. There was a clear border between the tumor and the pituitary stalk and optic nerves. Histopathologic examination showed that the tumor was well vascularized, consisting of a reticular mesh of numerous thin-walled capillaries and abundant stromal cells. Immunohistochemistry demonstrated the positive staining for CD34, vimentin (VIM), and neuron specific enolase (NSE) in the intratumoral capillaries, while negative staining of epithelial membrane antigen (EMA) and glial fibrillary acidic protein (GFAP) was observed. Based on these results, the patient was diagnosed as HBL. After the resection, the visual field defect in the left eye was markedly improved, and no tumor recurrence was noted in 1 year follow-up. When solid lesions are highly vascularized in the suprasellar region of patients, even though no VHL disease is present, the possibility of HBL should be taken into consideration. Moreover, craniotomy is a better treatment option for suprasellar HBL without VHL disease.

Functional Neuronavigation-Guided Transparieto-Occipital Cortical Resection of Meningiomas in Trigone of Lateral Ventricle

BACKGROUND

This study investigated whether functional neuronavigation can be used to remove lesions in the lateral ventricle while preserving patients' neurologic functionality.

METHODS

A total of 60 patients with lateral ventricular meningiomas were divided into study and control groups (n = 30 each). Diffusion tensor and blood oxygenation level-dependent functional magnetic resonance imaging were used for fiber tracking and eloquent cortex localization, respectively, in the study group. The surgical approach was based on coregistered data sets from 3-D lesion and brain structure reconstructions. Patients in the control group underwent anatomic neuronavigation-guided surgery. The patients' demographics, degree of resection, visual field, language score, movement, preoperative and postoperative Karnofsky Performance Status (KPS) scores, and surgical complications were recorded.

RESULTS

Tumors were completely removed in both groups. Patients in the study group had a higher rate of visual field preservation than controls (P = 0.01). The two groups had similar motor and language functions after surgery, except that fewer cases of transient aphasia were observed in the former (P < 0.05). KPS scores for the study and control groups were 80 (70-80) and 70 (60-70), respectively (P < 0.01), at 2 weeks and 90 (80-100) and 85 (70-90), respectively (P = 0.022), at 3 months after surgery.

CONCLUSIONS

Functional neuronavigation preserved neurologic functionality and was especially beneficial for protecting optical functionality and for the rapid recovery of patients.

Purely endoscopic endonasal surgery of the craniovertebral junction: A systematic review

BACKGROUND

Endoscopic endonasal surgery (EES) is a relatively novel approach to the craniovertebral junction (CVJ). The purpose of this analysis is to determine the surgical outcomes of patients who undergo purely EES of the CVJ.

METHODS

A search for articles related to EES of the CVJ was performed using the MEDLINE/PubMed database. A bibliographic search was done for additional articles. Demographics, presenting symptoms, imaging findings, complications, follow-up, and patient outcomes were analyzed.

RESULTS

Eighty-five patients from 30 articles were included. The mean patient age was 47.9 ± 24.8 years (range, 3 to 96 years), with 44.7% being male. The most common presenting symptom was myelopathy (n = 64, 75.3%). The most common indications for surgery were brainstem compression secondary to basilar invagination (n = 41, 48.2%) and odontoid pannus (n = 20, 23.5%). Odontoidectomy was performed in 97.6% of cases. Intraoperative complications occurred in 16 patients (18.8%) and postoperative complications occurred in 18 patients (21.2%). Six patients developed postoperative respiratory failure necessitating a tracheostomy. Neurologic improvement was seen in 89.4% of patients at a mean follow-up of 22.2 months.

CONCLUSION

Our analysis found that EES of the CVJ results in a high rate of neurologic improvement with acceptable complication rates. Given its minimally invasive nature and high success rate, this approach appears to be a reasonable alternative to the traditional transoral approach in select cases. This study represents the largest pooled sample size of EES of the CVJ to date. Increasing use of the endoscopic endonasal approach will allow for further studies with greater statistical power.

Posterior interhemispheric transfalcine transprecuneus approach for microsurgical resection of periatrial lesions: indications, technique, and outcomes

OBJECT

Surgical exposure of the peritrigonal or periatrial region has been challenging due to the depth of the region and overlying important functional cortices and white matter tracts. The authors demonstrate the operative feasibility of a contralateral posterior interhemispheric transfalcine transprecuneus approach (PITTA) to this region and present a series of patients treated via this operative route.

METHODS

Fourteen consecutive patients underwent the PITTA and were included in this study. Pre- and postoperative clinical and radiological data points were retrospectively collected. Complications and extent of resection were reviewed.

RESULTS

The mean age of patients at the time of surgery was 39 years (range 11-64 years). Six of the 14 patients were female. The mean duration of follow-up was 4.6 months (range 0.5-19.6 months). Pathology included 6 arteriovenous malformations, 4 gliomas, 2 meningiomas, 1 metastatic lesion, and 1 gray matter heterotopia. Based on the results shown on postoperative MRI, 1 lesion (7%) was intentionally subtotally resected, but ≥ 95% resection was achieved in all others (93%) and gross-total resection was accomplished in 7 (54%) of 13. One patient (7%) experienced a temporary approach-related complication. At last follow-up, 1 patient (7%) had died due to complications of his underlying malignancy unrelated to his cranial surgery, 2 (14%) demonstrated a Glasgow Outcome Scale (GOS) score of 4, and 11 (79%) manifested a GOS score of 5.

CONCLUSIONS

Based on this patient series, the contralateral PITTA potentially offers numerous advantages, including a wider, safer operative corridor, minimal need for ipsilateral brain manipulation, and better intraoperative navigation and working angles.

Hyperdense suprasellar mass: An unusual radiological presentation of intracranial dermoid cyst

We report an exceedingly rare patient with a hyperdense suprasellar dermoid cyst and a pertinent review of the literature. Intracranial dermoid tumors are rare congenital lesions of the brain that account for less than 1% of all intracranial tumors. Even though they are rare, typical CT scan and MRI features and location allow radiological diagnosis in the majority of patients. Radiologically, dermoid cysts typically present as low density masses on CT scan and are generally hyperintense on T1-weighted MRI sequences with variable signal on T2-weighted sequences. The recognition of atypical features can avoid diagnostic pitfalls and is clinically relevant for overall surgical management.