Modified orbitozygomatic craniotomy for craniopharyngioma resection in children

Visual outcomes after treatment of craniopharyngioma in children: A systematic review

OBJECTIVE

Craniopharyngiomas (CP) are rare brain tumors that often result in visual impairment due to their proximity to the optic pathway. The optimal management approach to preserve visual function in these patients remains controversial. We sought to investigate visual outcomes of children with craniopharyngiomas based on treatment modality.

METHODS

A systematic review was performed according to PRISMA guidelines. PubMed, Embase, and Scopus databases were searched in December 2022 for relevant articles. Articles were screened by title/abstract for relevance, then by full-text. Relevant demographic, intervention, and outcome data were extracted from included studies.

RESULTS

A total of 59 studies were included, representing 2655 patients. The overall visual status (OVS) of patients receiving surgery alone was improved in 27.6% of reported outcomes, unchanged in 50.3%, and deteriorated in 22.1%. The OVS for patients receiving radiation alone was improved in 21.1%, unchanged in 42.1%, and deteriorated in 36.8%. Patients receiving surgery plus adjuvant radiotherapy had OVS improvement in 27.4%, unchanged in 63.2%, and deteriorated in 9.4%. Of those receiving intracystic bleomycin, 23.1% had improvement in OVS, 46.2% remained unchanged, and 30.8% deteriorated. Of patients receiving interferon-α, 34.8% improved, 54.5% remained unchanged, and 10.6% deteriorated.

CONCLUSION

OVS most frequently remained unchanged regardless of intervention. The greatest improvement in OVS was seen in those receiving interferon-α or surgery alone. The greatest OVS deterioration was noted with radiation alone. Future standardized, randomized, large-scale studies with focused assessment of ophthalmologic findings are key to further understanding the impact different interventions have on visual outcomes in these children.

Comparing Surgical Approaches for Craniopharyngioma Resection Among Adults and Children: A Meta-analysis and Systematic Review

BACKGROUND

Craniopharyngioma treatment often necessitates surgical resection. Conventional approaches, such as transcranial and transsphenoidal approaches, are predominantly used. However, a recently adopted supraorbital approach may be more efficacious. Thus, this meta-analysis and systematic review aimed to compare the efficacy of the transcranial, transsphenoidal, and supraorbital approaches for resection and treatment of craniopharyngiomas.

METHODS

This study was performed following PRISMA guidelines. Analyses were performed according to study design: (1) analyses for studies comparing several surgical approaches; and (2) analyses of all included studies. Random effects meta-analysis models were used to pool odds ratios among studies comparing several approaches. Similarly, categorical meta-regression models were used to examine the effect of surgical approach as a covariate of outcome data for all studies. Statistics were performed using Comprehensive Meta-Analysis software (CMA 3.3, Biostat, Englewood, NJ) (significance set at P < 0.05).

RESULTS

Patients were well-matched for age, sex, and preoperative comorbidities between groups stratified by surgical approach. Analyses including 22 studies that compared several approaches demonstrated that the transsphenoidal group had a greater occurrence of postoperative visual improvement (P < 0.0001), lesser occurrence of visual deterioration (P < 0.0001), and lower tumor recurrence rate (P = 0.015) compared with the transcranial group. Only 2 studies compared the supraorbital approach to another approach, limiting analyses. Analyses including all studies demonstrated that the supraorbital group did not differ to either the transcranial or transsphenoidal group for any examined variables.

CONCLUSIONS

The present study suggests that the transsphenoidal approach is associated with improved clinical outcomes for craniopharyngioma resection. There are limited data regarding the supraorbital approach, warranting future investigation.

Characteristics and Outcomes in Pediatric Versus Adult Craniopharyngiomas: A Systematic Review and Meta-Analysis

BACKGROUND

Craniopharyngiomas account for 1.2% to 4.6% of all intracranial tumors. Although age at presentation is distributed bimodally, with a pediatric peak occurring between 5 and 15 years and an adult peak between 50 and 70 years, presentation, treatment, and outcome differences between these two craniopharyngioma populations have not been thoroughly characterized.

OBJECTIVE

To compare treatments and outcomes between adult and pediatric craniopharyngiomas.

METHODS

This is a systematic review and meta-analysis. Web of Science, MEDLINE, and Scopus databases were searched for primary studies reporting postoperative complications, functional outcomes, recurrence, and overall survival in patients with craniopharyngioma undergoing surgery.

RESULTS

The search yielded 1,202 unique articles, of which 106 (n=4,202 patients) met criteria for qualitative synthesis and 23 (n=735 patients) met criteria for meta-analysis. Compared with adult, pediatric craniopharyngiomas were less likely to present with visual defects (odds ratio [OR] 0.54, 95% CI 0.36-0.80) or cognitive impairment (OR 0.29, 95% CI 0.12-0.71) and more likely with headaches (OR 2.08, 95% CI 1.16-3.73). Children presented with significantly larger tumors compared with adults (standardized mean difference 0.68, 95% CI 0.38-0.97). Comparing functional outcomes, pediatric patients sustained higher rates of permanent diabetes insipidus (OR 1.70, 95% CI 1.13-2.56), obesity (OR 3.15, 95% CI 1.19-8.31), and cranial nerve and/or neurological defects (OR 4.87, 95% CI 1.78-13.31) than adults. No significant differences were found in rates of postoperative cerebrospinal fluid leak, overall or progression-free survival, or recurrence.

CONCLUSION

Adult and pediatric craniopharyngiomas seem to have fundamental differences in clinical presentation and functional outcomes. These patients frequently require multimodality treatment and are best managed with a multidisciplinary team and an individualized approach.

Contemporary Biological Insights and Clinical Management of Craniopharyngioma

Craniopharyngiomas (CPs) are clinically aggressive tumors because of their invasive behavior and recalcitrant tendency to recur after therapy. There are 2 types based on their distinct histology and molecular features: the papillary craniopharyngioma (PCP), which is associated with BRAF-V600E mutations and the adamantinomatous craniopharyngioma (ACP), characterized by mutations in CTNNB1 (encoding β-catenin). Patients with craniopharyngioma show symptoms linked to the location of the tumor close to the optic pathways, hypothalamus, and pituitary gland, such as increased intracranial pressure, endocrine deficiencies, and visual defects. Treatment is not specific and mostly noncurative, and frequently includes surgery, which may achieve gross total or partial resection, followed by radiotherapy. In cystic tumors, frequent drainage is often required and intracystic instillation of drugs has been used to help manage cyst refilling. More recently targeted therapies have been used, particularly in PCP, but also now in ACP and clinical trials are underway or in development. Although patient survival is high, the consequences of the tumor and its treatment can lead to severe comorbidities resulting in poor quality of life, in particular for those patients who bear tumors with hypothalamic involvement. Accordingly, in these patients at risk for the development of a hypothalamic syndrome, hypothalamus-sparing treatment strategies such as limited resection followed by irradiation are recommended. In this review, we provide an update on various aspects of CP, with emphasis on recent advances in the understanding of tumor pathogenesis, clinical consequences, management, and therapies.

Defining the Clival Recess Surgical Corridor and Clival Classification System for Approach to Sellar Pathology

BACKGROUND

Sellar masses within the pars intermedius, bordered anteriorly by normal pituitary gland/stalk, and/or with ectatic cavernous carotid anatomy are challenging and high risk when approached through the endonasal standard direct/anterior sellar approach. This approach portends itself to a higher risk of pituitary gland/stalk injury and subtotal resection with the aforementioned anatomic variants.

OBJECTIVE

To describe the indirect clival recess corridor approach to sellar lesions. This corridor is a "silent" point of access to lesions in this region endoscopically. While skull base teams may have used this approach to some degree, it has not yet been described in the literature to our knowledge.

METHODS

We defined the clival recess surgical corridor with skull base craniometric measurements and use a case example with aberrant anatomy to illustrate the approach. We cross-sectionally reviewed 42 patients with sellar and suprasellar masses. To describe the approach's anatomy, we devised and defined the terms dorsum sella plumb line, anatomic corridor, angle of osseous, and operative corridor.

RESULTS

Created novel clival aeration grade informing surgical planning. Classified clival aeration as Grade 1 (100%-75% aeration), Grade 2 (75%-50% aeration), Grade 3 (50%-25% aeration), and Grade 4 (25%-0% aeration). This classification system determines extent of drilling of the clivus required to optimize the clival recess corridor approach and its limitations.

CONCLUSION

The clival recess surgical corridor is effective for accessing pituitary lesions within the sella. Consider the indirect approach when a standard direct/anterior sellar approach has high risk for vascular injury and/or endocrinological dysfunction.

Petrosal Approach for Giant Retrochiasmatic Craniopharyngioma: 2-Dimensional Operative Video

Microsurgical resection of craniopharyngiomas poses significant challenges, which are amplified with tumors in the retrochiasmatic location and larger size. Traditional pterional trans-sylvian, subfrontal translamia terminalis, or interhemispheric approaches provide narrow surgical corridors with obstructed visualization of the tumor by the prefixed chiasm and slit optic carotid window.1-5 The superior extension of the tumor compressing the hypothalamus and third ventricle are likewise inaccessible. Dissection through these approaches requires crossing and manipulation of the already compromised optic apparatus with surgical instruments. Finally, the basilar artery and its perforating branches are often adherent to the posterior aspect of the tumor, and are invisible. Endonasal endoscopic techniques have been utilized as a surgical approach that accesses the tumor without crossing the optic apparatus; however, these approaches have a significant risk of cerebrospinal fluid leakage and require dissection of the basilar artery and hypothalamus from long distances with lengthy instruments.6-9 Frequently, the surgeon achieves only partial removal. The petrosal approach is ideal for tumors in the retrochiasmatic location.10-13 Advantages include unhindered access to the retrochiasmatic space without crossing the optic nerve and chiasm. The angle of approach allows visualization superiorly to the hypothalamus. Additionally, the approach shortens the distance to the tumor, allowing for delicate bimanual dissection of the tumor, especially at the basilar artery and hypothalamic interfaces. This video demonstrates three cases of retrochiasmatic craniopharyngioma resection through the petrosal approach, highlighting these advantages to optimize patient outcome. The patients and guardians consented for the surgery, photography, and publication of the patient's image. Figures from Al-Mefty et al11 used with permission from the Journal of Neurosurgery Publishing Group. Additional figures republished from Al-Mefty et al.12 "The petrosal approach for the resection of retrochiasmatic craniopharyngiomas," Neurosurgery, 2008, volume 62, issue 5 Suppl 2 (ONS), ONS331-ONS336, by permission of the Congress of Neurological Surgeons.

Pediatric Intracavernous Sinus Lesions: A Single Institutional Surgical Case Series and Review of the Literature

BACKGROUND

Pediatric intracavernous sinus tumors are exceedingly rare and thus poorly characterized. Their neurosurgical management is challenging and diagnostic, and management guidelines are limited.

OBJECTIVE

To report our institutional experience with the surgical resection of pediatric intracavernous sinus tumors. We also compare and contrast our results with the 14 cases of pediatric intracavernous sinus lesions in the current literature.

METHODS

A retrospective descriptive analysis of consecutive pediatric patients (ages 0-18 yr) presenting to our institution with a diagnosis of an intracavernous sinus lesion was performed. From January 2012 to January 2017, 5 cases were identified. Eleven patients with secondary invasion of the cavernous sinus (2 meningiomas, 7 pituitary adenomas) or dermoid tumors involving the cavernous sinus (2) were not included in our review.

RESULTS

Surgical resection via a frontotemporal orbitozygomatic approach was performed in all cases by a single senior neurosurgeon (M.L.). There were no perioperative or postoperative complications attributable to the surgery or approach. Four of 5 patients remained neurologically stable throughout the perioperative and postoperative period. The fifth patient had a complete resolution of their cranial neuropathies postoperatively. A pathological diagnosis that guided long-term management was obtained in all cases.

CONCLUSION

Neurosurgical management of pediatric cavernous sinus lesions can be safely performed and critically guide future therapies. Surgeon familiarity with cavernous sinus and skull-base anatomy is critical to the successful management of these patients. The benefits of surgery should be balanced against the potential complications and need for a tissue diagnosis in children. The senior author had a significant experience with cavernous sinus approaches in adults prior to initiating use of the approach in the pediatric population.

Pediatric Craniopharyngiomas: A Primer for the Skull Base Surgeon

Pediatric craniopharyngioma is a rare sellar-region epithelial tumor that, in spite of its typically benign pathology, has the potential to be clinically devastating, and presents a host of formidable management challenges for the skull base surgeon. Strategies in craniopharyngioma care have been the cause of considerable controversy, with respect to both philosophical and technical issues. Key questions remain unresolved, and include optimizing extent-of-resection goals; the ideal radiation modality and its role as an alternative, adjuvant, or salvage treatment; appropriate indications for expanded endoscopic endonasal surgery as an alternative to transcranial microsurgery; risks and benefits of skull base techniques in a pediatric population; benefits of and indications for intracavitary therapies; and the preferred management of common treatment complications. Correspondingly, we sought to review the preceding basic science and clinical outcomes literature on pediatric craniopharyngioma, so as to synthesize overarching recommendations, highlight major points of evidence and their conflicts, and assemble a general algorithm for skull base surgeons to use in tailoring treatment plans to the individual patient, tumor, and clinical course. In general terms, we concluded that safe, maximal, hypothalamic-sparing resection provides very good tumor control while minimizing severe deficits. Endoscopic endonasal, intraventricular, and transcranial skull base technique all have clear roles in the armamentarium, alongside standard craniotomies; these roles frequently overlap, and may be further optimized by using the approaches in adaptive combinations. Where aggressive subtotal resection is achieved, patients should be closely followed, with radiation initiated at the time of progression or recurrence-ideally via proton beam therapy, although three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and stereotactic radiosurgery are very appropriate in a range of circumstances, governed by access, patient age, disease architecture, and character of the recurrence. Perhaps most importantly, outcomes appear to be optimized by consolidated, multidisciplinary care. As such, we recommend treatment in highly experienced centers wherever possible, and emphasize the importance of longitudinal follow-up-particularly given the high incidence of recurrences and complications in a benign disease that effects a young patient population at risk of severe morbidity from hypothalamic or pituitary injury in childhood.

Developmental Considerations in Pediatric Skull Base Surgery

Objectives  To review developmental surgical anatomy and technical nuances related to pediatric skull base surgery. Design  Retrospective, single-center case series with literature review. Setting  MD Anderson Cancer Center. Participants  Patients undergoing pediatric skull base surgery. Main Outcome Measures  Review developmental anatomy of the pediatric skull base as it relates to technical nuance of various surgical approaches and insight gained from a 25-year institutional experience with this unique patient population. Results  Thirty-nine patients meeting these criteria were identified over a 13-year period from 2003 to 2016 and compared to a previously reported earlier cohort from 1992 to 2002. The most common benign pathologies included nerve sheath tumors (11%), juvenile nasopharyngeal angiofibromas (9.5%), and craniopharyngiomas (4.8%). The most common malignancies were chondrosarcoma (11%), chordoma (11%), and rabdomyosarcoma (11%). Varied surgical approaches were utilized and were similar between the two cohorts save for the increased use of endoscopic surgical techniques in the most recent cohort. The most common sites of tumor origin were the infratemporal fossa, sinonasal cavities, clivus, temporal bone, and parasellar region. Gross total resection and postoperative complication rates were similar between the two patient cohorts. Conclusions  Pediatric skull base tumors, while rare, often are treated surgically, necessitating an in depth understanding of the anatomy of the developing skull base.

Microscopic versus endoscopic approaches for craniopharyngiomas: choosing the optimal surgical corridor for maximizing extent of resection and complication avoidance using a personalized, tailored approach

Resection remains the mainstay of treatment for craniopharyngiomas with the goal of radical resection, if safely possible, to minimize the rate of recurrence. Endoscopic endonasal and microscopic transcranial surgical approaches have both become standard methods for the treatment for craniopharyngiomas. However, the approach selection paradigm for craniopharyngiomas is still a point of discussion. Choosing the optimal surgical approach can play a significant role in maximizing the extent of resection and surgical outcome while minimizing the risks of potential complications. Craniopharyngiomas can present with a variety of different sizes, locations, and tumor consistencies, and each individual tumor has distinct features that favor one specific approach over another. The authors review standard cranial base techniques applied to craniopharyngioma surgery, using both the endoscopic endonasal approach and traditional open microsurgical approaches, and analyze factors involved in approach selection. They discuss their philosophy of approach selection based on the location and extent of the tumor on preoperative imaging as well as the advantages and limitations of each surgical corridor, and they describe the operative nuances of each technique, using a personalized, tailored approach to the individual patient with illustrative cases and videos.

Fronto-orbitozygomatic approach: functional and cosmetic outcomes in a series of 169 patients

OBJECTIVE Advantages of the fronto-orbitozygomatic (FOZ) approach have been reported extensively in the literature; nevertheless, restoration of normal anatomy and the esthetic impact of surgery are increasingly important issues for patients and neurosurgeons. The aim of this study was to analyze functional and cosmetic outcomes in a series of 169 patients with different pathologies who underwent surgery in which the FOZ approach was used. METHODS Between January 2000 and December 2014, 250 consecutive patients underwent surgery with an FOZ approach as the primary surgical treatment. Follow-up data were available for only 169 patients; 103 (60.9%) of these patients were female and 66 (39.1%) were male, and their ages ranged from 6 to 77 years (mean 46.9 years; SD 15.6 years). Mean follow-up time was 66 months (range 6-179 months; SD 49.5 months). Evaluation of clinical outcomes was performed with a focus on 4 main issues: surgical complications, functional outcome, cosmetic outcome, and patient satisfaction. The additional time needed to perform orbitotomy and orbital reconstruction was also evaluated. RESULTS The permanent postoperative complications included forehead hypesthesia (41.4%) and dysesthesia (15.3%), frontal muscle weakness (10.3%), exophthalmos (1.4%), enophthalmos (4.1%), diplopia (6.6%; 2% were related to surgical approach), and persistent periorbital and eyelid swelling (3%). Approximately 90% of the patients reported subjectively that surgery did not affect their quality of life or complained of only minor problems that did not influence their quality of life significantly. The mean time needed for orbitotomy and orbital reconstruction was approximately half an hour. CONCLUSIONS Comprehensive knowledge of the potential complications and overall clinical outcomes of the FOZ approach can be of great utility to neurosurgeons in balancing the well-known benefits of the approach with potential additional morbidities.

Microsurgical removal of craniopharyngioma: endoscopic and transcranial techniques for complication avoidance

Craniopharyngioma remains a challenging entity for neurosurgeons because of its midline, deep seated location and intimate relationship with critical neurovascular structures. Although gross total resection is ideal, the need to reduce surgical morbidity and preserve quality of life has led to a number of neurosurgical approaches which have attained this goal. Here we discuss the commonly used approaches for surgical resection and highlight technical considerations to reduce the potential of complications. We also discuss the mutually exclusive underlying genetic lesions in different histopathological subtypes that will likely lead to future treatment options for these tumors.

One Piece Orbitozygomatic Approach Based on the Sphenoid Ridge Keyhole: Anatomical Study

The one-piece orbitozygomatic (OZ) approach is traditionally based on the McCarty keyhole. Here, we present the use of the sphenoid ridge keyhole and its possible advantages as a keyhole for the one-piece OZ approach. Using transillumination technique the osteology of the sphenoid ridge was examined on 20 anatomical dry skull specimens. The results were applied to one-piece OZ approaches performed on freshly frozen cadaver heads. We defined the center of the sphenoid ridge keyhole as a superficial projection on the lateral skull surface of the most anterior and thickest part of the sphenoid ridge. It was located 22 mm (standard deviation [SD], 0.22 mm) from the superior temporal line; 10.7 mm (SD, 0.08 mm) posterior and 7.1 mm (SD, 0.22 mm) inferior to the frontozygomatic suture. The sphenoid ridge burr hole provides exposure of frontal, temporal dura as well as periorbita, which is essential for the later bone cuts. There is direct access to removal of the thickest (sphenoidal) part of the orbital roof, after which the paper-thin (frontal) part of the orbital roof is easily fractured. The sphenoid ridge is an easily identifiable landmark on the lateral skull surface, located below the usual placement of the McCarty keyhole, with comparative exposure.

Comparison of surgical exposure and maneuverability associated with microscopy and endoscopy in the retrolabyrinthine and transcrusal approaches to the retrochiasmatic region: a cadaveric study

BACKGROUND

The retrolabyrinthine and transcrusal approaches (RLA and TCA, respectively) are the two most often used posterior transpetrosal approaches that are used to treat lesions in the retrochiasmatic region. Endoscopes are increasingly used in neurosurgical practice. To determine whether a difference exists between the two transpetrosal approaches in the retrochiasmatic region, we evaluated and compared the exposure and maneuverability associated with the microscope and the endoscope in these approaches.

METHODS

Seven formalin-fixed cadaveric heads were dissected bilaterally through the two approaches: four for evaluation and three injected with colored latex for photography. The retrochiasmatic region was divided into four sub-compartments: the compartment before the infundibulum, which was further divided into two parts, (1) the ipsilateral and (2) the contralateral compartments; (3) the retroinfundibulum compartment; (4) the third ventricle. After each approach, exposure and maneuverability of the structures in these four compartments obtained by microscopy and endoscopy were scored under a guidance of a numerical grading system for further comparison.

RESULTS

The TCA provided better exposure and maneuverability at the retrochiasmatic region than the RLA in both the microscopy model [scores of 39.75 ± 2.12 and 32.38 ± 2.56 respectively (p < 0.05)] and the endoscopy model [scores of 82.13 ± 3.40 and 43.75 ± 1.67 respectively (p < 0.05)].

CONCLUSIONS

The TCA is better than the RLA at offering exposure and manipulation to structures in the retrochiasmatic region, especially in patients whose lesion is located high into the third ventricle and/or expanded into the contralateral part. Endoscopes may be helpful in TCA in terms of exposing and maneuvering structures in the contralateral and interpeduncle fossa areas. However, in RLA, not enough room is available for simultaneously maneuvering an endoscope and a surgical instrument.

Extended endoscopic endonasal transsphenoidal approach for retrochiasmatic craniopharyngioma: Surgical technique and results

Objective:

Surgical treatment of retrochiasmatic craniopharyngioma still remains a challenge. While complete removal of the tumor with preservation of the vital neurovascular structures is often the goal of the treatment, there is no optimal surgical approach available to achieve this goal. Transcranial and transsphenoidal microsurgical approaches, commonly used in the past, have considerable technical limitations. The extended endonasal endoscopic surgical route, obtained by removal of tuberculum sellae and planum sphenoidale, offers direct midline access to the retrochiasmatic space and provides excellent visualization of the undersurface of the optic chiasm. In this report, we describe the technical details of the extended endoscopic approach, and review our results using this approach in the surgical management of retrochiasmatic craniopharyngiomas.

Methods:

Fifteen children, including 9 girls and 6 boys, aged 8 to 15 years underwent surgery using extended endoscopic transsphenoidal approach between 2008 and 2014. Nine patients had a surgical procedure done previously and presented with recurrence of symptoms and regrowth of their residual tumors.

Results:

A gross total or near total excision was achieved in 10 (66.7%) patients, subtotal resection in 4 (26.7%), and partial removal in 1 (6.7%) patient. Postoperatively, headache improved in 93.3%, vision recovered in 77.3%, and the hormonal levels stabilised in 66.6%. Three patients (20%) developed postoperative CSF leaks which were managed conservatively. Three (20%) patients with diabetes insipidus and 2 (13.3%) with panhypopituitarism required long-term hormonal replacement therapy.

Conclusions:

Our early experience suggests that the extended endonasal endoscopic approach is a reasonable option for removal of the retrochiasmal craniopharyngiomas. Compared to other surgical approaches, it provides better opportunities for greater tumor removal and visual improvement without any increase in risks.

Anatomic comparison of the endonasal and transpetrosal approaches for interpeduncular fossa access

OBJECT

The interpeduncular cistern, including the retrochiasmatic area, is one of the most challenging regions to approach surgically. Various conventional approaches to this region have been described; however, only the endoscopic endonasal approach via the dorsum sellae and the transpetrosal approach provide ideal exposure with a caudal-cranial view. The authors compared these 2 approaches to clarify their limitations and intrinsic advantages for access to the interpeduncular cistern.

METHODS

Four fresh cadaver heads were studied. An endoscopic endonasal approach via the dorsum sellae with pituitary transposition was performed to expose the interpeduncular cistern. A transpetrosal approach was performed bilaterally, combining a retrolabyrinthine presigmoid and a subtemporal transtentorium approach. Water balloons were used to simulate space-occupying lesions. "Water balloon tumors" (WBTs), inflated to 2 different volumes (0.5 and 1.0 ml), were placed in the interpeduncular cistern to compare visualization using the 2 approaches. The distances between cranial nerve (CN) III and the posterior communicating artery (PCoA) and between CN III and the edge of the tentorium were measured through a transpetrosal approach to determine the width of surgical corridors using 0- to 6-ml WBTs in the interpeduncular cistern (n = 8).

RESULTS

Both approaches provided adequate exposure of the interpeduncular cistern. The endoscopic endonasal approach yielded a good visualization of both CN III and the PCoA when a WBT was in the interpeduncular cistern. Visualization of the contralateral anatomical structures was impaired in the transpetrosal approach. The surgical corridor to the interpeduncular cistern via the transpetrosal approach was narrow when the WBT volume was small, but its width increased as the WBT volume increased. There was a statistically significant increase in the maximum distance between CN III and the PCoA (p = 0.047) and between CN III and the tentorium (p = 0.029) when the WBT volume was 6 ml.

CONCLUSIONS

Both approaches are valid surgical options for retrochiasmatic lesions such as craniopharyngiomas. The endoscopic endonasal approach via the dorsum sellae provides a direct and wide exposure of the interpeduncular cistern with negligible neurovascular manipulation. The transpetrosal approach also allows direct access to the interpeduncular cistern without pituitary manipulation; however, the surgical corridor is narrow due to the surrounding neurovascular structures and affords poor contralateral visibility. Conversely, in the presence of large or giant tumors in the interpeduncular cistern, which widen the spaces between neurovascular structures, the transpetrosal approach becomes a superior route, whereas the endoscopic endonasal approach may provide limited freedom of movement in the lateral extension.

Techniques for Preservation of the Frontotemporal Branch of Facial Nerve during Orbitozygomatic Approaches

Background During orbitozygomatic (OZ) approaches, the frontotemporal branch (FTB) of the facial nerve is exposed to injury if proper measures are not taken. This article describes in detail the nuances of the two most common techniques (interfascial and subfascial dissection). Design The FTB of the facial nerve was dissected and followed in its tissue planes on fresh-frozen cadaver heads. The interfascial and subfascial dissections were performed, and every step was photographed and examined. Results The interfascial dissection is safe to be started from the most anterior part of the superior temporal line and followed to the root of the zygoma. The dissection is continued on the deep temporalis fascia (DTF), and the interfascial fat pad is elevated. With the subfascial dissection, both the superficial temporalis fascia and the DTF are elevated. The interfascial dissection exposes the zygomatic arch directly, whereas the subfascial dissection requires an additional cut on the DTF to expose the zygomatic arch. Proper subperiosteal dissection on the zygomatic arch is another important step in FTB preservation. Conclusion Detailed understanding of the complex relationship of the tissue planes in the frontotemporal region is needed to perform OZ exposures safely.

Microsurgical resection of extensive craniopharyngiomas using a frontolateral approach: operative technique and outcome

OBJECT

An extensive craniopharyngioma is a tumor that extends into multiple compartments (subarachnoid spaces) and attains a size larger than 4 cm. A wide spectrum of approaches and strategies has been used for resection of such craniopharyngiomas. In this report the authors focused on the feasibility and efficacy of microsurgical resection of extensive craniopharyngiomas using a frontolateral approach.

METHODS

A retrospective analysis was performed on 16 patients with extensive craniopharyngiomas who underwent operations using a frontolateral approach at one institution. The preoperative and postoperative clinical and radiological data, as well as the operative videos, were reviewed. The main focus of the review was the extent of radical tumor removal, early postoperative outcome, and approach-related complications.

RESULTS

Gross-total resection of craniopharyngioma was achieved in 14 (87.5%) of 16 cases. Early after surgery (within 3 months), 1 patient showed improvement in hormonal status, while in the remaining 15 patients it worsened. No major neurological morbidity was observed. Two patients experienced temporary psychotic disorders. Visual function improved in 6 patients and remained unchanged in 9. One patient experienced a new bitemporal hemianopsia. Three patients with features of short-term memory disturbances at presentation did show improvement after surgery. There were no deaths or significant approach-related morbidity in this patient series. Only 1 patient required revision surgery for a CSF leak.

CONCLUSIONS

The safe and simple frontolateral approach provides adequate access even to extensive craniopharyngiomas and enables their complete removal with a reasonable morbidity and approach-related complication rate.

Surgical outcomes of the minimum anterior and posterior combined transpetrosal approach for resection of retrochiasmatic craniopharyngiomas with complicated conditions

OBJECT

Retrochiasmatic craniopharyngiomas are surgically challenging tumors. Retrochiasmatic craniopharyngiomas with complicated conditions such as large diameter, major calcification, or significant extension to the third ventricle or posterior fossa present surgical challenges; moreover, recurrent retrochiasmatic craniopharyngiomas are particularly formidable challenges. Although the transpetrosal approach to retrochiasmatic craniopharyngiomas published by Hakuba in 1985 can provide unique advantageous exposure of the retrochiasmatic area to allow safe neurovascular dissection and facilitate radical tumor removal, the procedure is viewed as complicated and time consuming and has a high risk of damaging hearing functions. The authors have modified Hakuba's technique to minimize petrosectomy and reduce surgical complications and have applied this modified approach to retrochiasmatic craniopharyngiomas with complicated conditions. In this study, the authors describe their technique and surgical outcomes to elucidate the role of this modified transpetrosal approach for retrochiasmatic craniopharyngiomas with complicated conditions. This is the first study to report surgical outcomes of the transpetrosal approach for retrochiasmatic craniopharyngiomas.

METHODS

Between 1999 and 2011, the minimum anterior and posterior combined (MAPC) transpetrosal approach, which is a modification of Hakuba's transpetrosal approach, was applied in 16 cases of retrochiasmatic craniopharyngiomas with complicated conditions. Eight cases were recurrent tumors, 4 had previously received radiotherapy, 11 had a large diameter, 10 had large calcification, 15 had superior extension of the tumor into the third ventricle, and 10 had a posterior extension of the tumor that compressed the midbrain and pons. In all 16 patients, more than 2 of these complicated conditions were present. The follow-up duration ranged from 0.8 to 12.5 years (mean 5.3 years). Surgical outcomes assessed were the extent of resection, surgical complications, visual function, endocrinological status, and neuropsychological function. Five-year and 10-year recurrence-free survival rates were also calculated.

RESULTS

Gross-total or near-total resection was achieved in 15 cases (93.8%). Facial nerve function was completely maintained in all 16 patients. Serviceable hearing was preserved in 15 cases (93.8%). Visual function improved in 13 out of 14 cases (92.9%) that had visual disturbance before surgery. None of the patients experienced deterioration of their visual function. Twelve cases had endocrinological deficit and received hormonal replacement before surgery. New endocrinological deficit occurred in 2 cases (12.5%). Neuropsychological function was maintained in 14 cases (87.5%) and improved in 1 case (6.3%). One case that had received previous conventional radiotherapy treatment showed a gradual decline in neuropsychological function. The 5-year and 10-year recurrence-free survival rates were both 86.5%.

CONCLUSIONS

The authors obtained good results by using the MAPC transpetrosal approach for the removal of retrochiasmatic craniopharyngiomas with complicated conditions. The MAPC transpetrosal approach should be considered as a therapeutic option for selected cases of retrochiasmatic craniopharyngiomas with complicated conditions.

A systematic review of the results of surgery and radiotherapy on tumor control for pediatric craniopharyngioma

OBJECTIVE

Craniopharyngiomas are rare tumors with bimodal incidence in the pediatric and adult age groups. Treatment strategies range from aggressive resection to planned limited resection combined with adjuvant therapies. Currently there is no consensus for standard of care for pediatric craniopharyngioma.

MATERIALS AND METHODS

We performed a systematic review of the published literature on pediatric craniopharyngioma. Patients were grouped based on extent of resection into gross total resection (GTR), subtotal resection (STR), and biopsy procedures. These groups were compared with respect to tumor control. Chi square was used to compare rates of recurrence. Kaplan-Meier was used to generate progression-free survival (PFS) estimates. Cox proportional hazard modeling was used to evaluate risk of progression. Each extent of resection group was also subdivided based on adjuvant therapy and compared.

RESULTS

A total of 109 studies described extent of resection resulting in a cohort of 531 patients. Recurrence data were available for 377 patients. There was no difference in 1- or 5-year PFS between the groups who underwent GTR and STR combined with radiation (XRT; log-rank; p = 0.76; 1-year PFS 89 vs 84%; 5-year PFS 77 vs 73%, respectively). One-year PFS was 84% for STR+XRT compared to 76% for STR alone while 5-year PFS was 73% for STR+XRT compared to 43% for STR alone (log-rank; p = 0.003).

CONCLUSION

Although there are limitations of a systematic review of retrospective data, our results suggest that STR+XRT of pediatric craniopharyngioma is associated with similar rates of tumor control as GTR.

Predictive factors for vision recovery after optic nerve decompression for chronic compressive neuropathy: systematic review and meta-analysis

Objectives Surgical optic nerve decompression for chronic compressive neuropathy results in variable success of vision improvement. We sought to determine the effects of various factors using meta-analysis of available literature. Design Systematic review of MEDLINE databases for the period 1990 to 2010. Setting Academic research center. Participants Studies reporting patients with vision loss from chronic compressive neuropathy undergoing surgery. Main outcome measures Vision outcome reported by each study. Odds ratios (ORs) and 95% confidence intervals (CIs) for predictor variables were calculated. Overall odds ratios were then calculated for each factor, adjusting for inter study heterogeneity. Results Seventy-six studies were identified. Factors with a significant odds of improvement were: less severe vision loss (OR 2.31[95% CI = 1.76 to 3.04]), no disc atrophy (OR 2.60 [95% CI = 1.17 to 5.81]), smaller size (OR 1.82 [95% CI = 1.22 to 2.73]), primary tumor resection (not recurrent) (OR 3.08 [95% CI = 1.84 to 5.14]), no cavernous sinus extension (OR 1.88 [95% CI = 1.03 to 3.43]), soft consistency (OR 4.91 [95% CI = 2.27 to 10.63]), presence of arachnoid plane (OR 5.60 [95% CI = 2.08 to 15.07]), and more extensive resection (OR 0.61 [95% CI = 0.4 to 0.93]). Conclusions Ophthalmologic factors and factors directly related to the lesion are most important in determining vision outcome. The decision to perform optic nerve decompression for vision loss should be made based on careful examination of the patient and realistic discussion regarding the probability of improvement.

Treatment-related morbidity and the management of pediatric craniopharyngioma: a systematic review

OBJECT

Craniopharyngiomas are benign tumors but their close anatomical relationship with critical neurological, endocrine, and vascular structures makes gross-total resection (GTR) with minimal morbidity difficult to achieve. Currently, there is controversy regarding the extent, timing, and modality of treatment for pediatric craniopharyngioma.

METHODS

The authors performed a systematic review of the published literature on pediatric craniopharyngioma to determine patterns of clinical practice and the reported outcomes of standard treatment strategies. This yielded 109 studies, which contained data describing extent of resection for a total of 531 patients. Differences in outcome were examined based upon extent of resection and choice of radiation treatment.

RESULTS

Gross-total resection was associated with increased rates of new endocrine dysfunction (OR 5.4, p < 0.001), panhypopituitarism (OR 7.8, p = 0.006), and new neurological deficits (OR 9.9, p = 0.03) compared with biopsy procedures. Subtotal resection (STR) was not associated with an increased rate of new neurological deficits. Gross-total was associated with increased rates of diabetes insipidus (OR 7.7, p = 0.05) compared with the combination of STR and radiotherapy (RT). The addition of RT to STR was associated with increased rates of panhypopituitarism (OR 9.9, p = 0.01) but otherwise similar rates of morbidities.

CONCLUSIONS

Although subject to the limitations of a literature review, this report suggests that GTR is associated with increased rates of endocrinopathies compared with STR + RT, and this should be considered when planning goals of surgery.

Anatomic study of the lamina terminalis: neurosurgical relevance in approaching lesions within and around the third ventricle

BACKGROUND

The lamina terminalis (LT) represents an important neurosurgical corridor by which to fenestrate the third ventricle into the subarachnoid space or to approach lesions of the third ventricle. However, a comprehensive review of its anatomy and approaches to it for various pathologies is lacking in the literature. We studied the anatomy of the LT in 21 cadavers and described the LT as observed in cadaveric dissections. We also reviewed the literature regarding the detailed anatomy and pathology of the LT. In addition, a case illustration that demonstrates the use of this structure as a corridor to third ventricular tumors is presented. Our aim was to explore the anatomy of the LT through cadaveric dissection, a review of the literature, and a case study.

METHODS

Twenty-one adult cadaver heads underwent microdissection of the LT with a focus on the working distance available to enter the third ventricle and related vascular structures.

RESULTS

Inferior to the anterior communicating artery was the safer region to open due to the lack of perforating arteries. A working distance of approximately 1 cm can be expected through the LT.

CONCLUSIONS

This information may aid neurosurgeons during approaches through and around the LT.

Lateral orbital wall approach to the cavernous sinus

Object

Lesions of the cavernous sinus remain a technical challenge. The most common surgical approaches involve some variation of the standard frontotemporal craniotomy. Here, the authors describe a surgical approach to access the cavernous sinus that involves the removal of the lateral orbital wall.

Methods

To achieve exposure of the cavernous sinus, a lateral canthal incision is performed, and the lateral orbital rim and anterior lateral wall are removed, for later replacement at closure. The posterior lateral orbital wall is removed to the region of the superior and inferior orbital fissures. With reflection of the dural covering of the lateral cavernous sinus and removal of the anterior clinoid process, the cavernous sinus is exposed.

Results

Exposure and details of the procedure were derived from anatomical study in cadavers. After the approach, with removal of the anterior clinoid process, the entire cavernous sinus from the superior orbital fissure anteriorly to the Meckel cave posteriorly is exposed. More exposure to the lateral middle fossa, foramen spinosum, and petrous carotid artery is obtained by further removal of the lateral sphenoid wing. An illustrative case example for approaching a cavernous sinus meningioma is presented.

Conclusions

The translateral orbital wall approach provides a simple, rapid approach for lesions with primary or secondary involvement of the cavernous sinus. Advantages of this simple, extradural approach include the lack of brain retraction and no interruption of the temporalis muscle.

Endoscopic skull base surgery: a comprehensive comparison with open transcranial approaches

Little data exists comparing endoscopic endonasal approaches to pathology of the anterior skull base with more traditional transcranial and transsphenoidal microscopic approaches. In order to more fully characterize the role of endoscopy in the management of pathology of the anterior cranial base, we conducted a systematic review of case series and case reports documenting surgical and clinical outcomes. We found that for craniopharyngiomas, clival chordomas, esthesioneuroblastomas and giant pituitary adenomas, the endonasal endoscopic approach can result in equivalent or higher rates of gross total resection than open approaches. For meningiomas, however, open transcranial approaches are still able to achieve higher rates of total resection. CSF leak rates are higher for patients undergoing endoscopic surgery for meningiomas and craniopharyngiomas, but not for chordomas, esthesioneuroblastomas or giant pituitary adenomas. In certain patients, the endonasal endoscopic approach may be a safe and effective alternative for the treatment of a wide variety of skull base pathology, particularly those with small midline tumours.

Endoscopic endonasal compared with microscopic transsphenoidal and open transcranial resection of craniopharyngiomas

OBJECTIVE

Craniopharyngiomas have traditionally represented a challenge for open transcranial or transsphenoidal microscopic neurosurgery because of their anatomical location and proximity to vital neurovascular structures. The extended endoscopic endonasal transsphenoidal approach has been more recently developed as a potentially surgically aggressive, yet minimal access, alternative. To gain a more comprehensive assessment of the benefits and limitations of the various approaches to resection of craniopharyngiomas, we performed a systematic review of the available published reports after endoscope-assisted endonasal approaches and compared their results with transsphenoidal purely microscope-based or transcranial microscope-based techniques.

METHODS

We performed a MEDLINE search of the modern literature (1995-2010) to identify open and endoscopic surgical series for pediatric and adult craniopharyngiomas. Comparisons were made for patient and tumor characteristics as well as extent of resection, morbidity, and visual outcome. Statistical analyses of categorical variables were undertaken by the use of χ(2) and Fisher exact tests with post-hoc Bonferroni analysis to compare endoscopic, microsurgical transsphenoidal, and transcranial approaches.

RESULTS

Eighty eight studies, involving 3470 patients, were included. The endoscopic cohort had a significantly greater rate of gross total resection (66.9% vs. 48.3%; P < 0.003) and improved visual outcome (56.2% vs. 33.1%; P < 0.003) compared with the open cohort. The transsphenoidal cohort had similar outcomes to the endoscopic group. The rate of cerebrospinal fluid leakage was greater in the endoscopic (18.4%) and transsphenoidal (9.0%) than in the transcranial group (2.6%; P < 0.003), but the transcranial group had a greater rate of seizure (8.5%), which did not occur in the endonasal or transsphenoidal groups (P < 0.003).

CONCLUSIONS

The endoscopic endonasal approach is a safe and effective alternative for the treatment of certain craniopharyngiomas. Larger lesions with more lateral extension may be more suitable for an open approach, and further follow-up is needed to assess the long-term efficacy of this minimal access approach.

Surgical nuances for removal of retrochiasmatic craniopharyngioma via the endoscopic endonasal extended transsphenoidal transplanum transtuberculum approach

Retrochiasmatic craniopharyngiomas are challenging tumors to remove given their deep location and proximity to critical neurovascular structures. Complete surgical removal offers the best chance of cure and prevention of recurrence. The endoscopic endonasal extended transsphenoidal approach offers direct midline access to the retrochiasmatic space through a transplanum transtuberculum corridor. Excellent visualization of the undersurface of the optic chiasm and hypothalamus can be obtained to facilitate bimanual extracapsular dissection to permit complete removal of these formidable tumors. In this report the authors review the endoscopic endonasal extended transsphenoidal approach, with specific emphasis on technical operative nuances in removing retrochiasmatic craniopharyngiomas. An illustrative intraoperative video demonstrating the technique is also presented.

Surgical nuances for removal of retrochiasmatic craniopharyngiomas via the transbasal subfrontal translamina terminalis approach

Giant craniopharyngiomas in the retrochiasmatic space are challenging tumors, given the location and surrounding vital structures. Surgical removal remains the first line of therapy and offers the best chance of cure. For tumors with extension into the retrochiasmatic space, the authors use the translamina terminalis corridor via the transbasal subfrontal approach. Although the lamina terminalis can be accessed via anterolateral approaches (pterional or orbitozygomatic), the surgical view of the optic chiasm is oblique and prevents adequate visualization of the ipsilateral wall of the third ventricle. The transbasal subfrontal approach, on the other hand, offers the major advantage of direct midline orientation and access to the third ventricle through the lamina terminalis. This provides the significant advantage of visualization of both walls of the third ventricle and hypothalamus as well as inferior midline access to the interpeduncular cistern to permit safe neurovascular dissection and total tumor removal. In this report, the authors describe the transbasal subfrontal translamina terminalis approach, with specific emphasis on technical surgical nuances in removing retrochiasmatic craniopharyngiomas. An illustrative video demonstrating the technique is also presented.

A mental hook for learning the three-dimensional anatomy of the sphenoid bone: an angelic resemblance

The sphenoid bone seems to resemble a biblical angel. The angel had six wings, and used two to cover the eyes (lesser wings with optic canal representing the eyes), two to fly (greater wings), and two (broad lateral pterygoid plates) to cover the feet (medial pterygoid plates with hamulus). This illustration may help surgical trainees to conceptualise and understand the clinical implications of this wide-ranging bone.