The transplanum transtuberculum approaches for suprasellar and sellar-suprasellar lesions: avoidance of cerebrospinal fluid leak and lessons learned

The learning curve in endoscopic transsphenoidal skull-base surgery: a systematic review

BACKGROUND

The endoscopic endonasal transsphenoidal approach (EETA) has revolutionized skull-base surgery; however, it is associated with a steep learning curve (LC), necessitating additional attention from surgeons to ensure patient safety and surgical efficacy. The current literature is constrained by the small sample sizes of studies and their observational nature. This systematic review aims to evaluate the literature and identify strengths and weaknesses related to the assessment of EETA-LC.

METHODS

A systematic review was conducted following the PRISMA guidelines. PubMed and Google Scholar were searched for clinical studies on EETA-LC using detailed search strategies, including pertinent keywords and Medical Subject Headings. The selection criteria included studies comparing the outcomes of skull-base surgeries involving pure EETA in the early and late stages of surgeons' experience, studies that assessed the learning curve of at least one surgical parameter, and articles published in English.

RESULTS

The systematic review identified 34 studies encompassing 5,648 patients published between 2002 and 2022, focusing on the EETA learning curve. Most studies were retrospective cohort designs (88%). Various patient assortment methods were noted, including group-based and case-based analyses. Statistical analyses included descriptive and comparative methods, along with regression analyses and curve modeling techniques. Pituitary adenoma (PA) being the most studied pathology (82%). Among the evaluated variables, improvements in outcomes across variables like EC, OT, postoperative CSF leak, and GTR. Overcoming the initial EETA learning curve was associated with sustained outcome improvements, with a median estimated case requirement of 32, ranging from 9 to 120 cases. These findings underscore the complexity of EETA-LC assessment and the importance of sustained outcome improvement as a marker of proficiency.

CONCLUSIONS

The review highlights the complexity of assessing the learning curve in EETA and underscores the need for standardized reporting and prospective studies to enhance the reliability of findings and guide clinical practice effectively.

Rarely Used Endoscopic Transnasal Transdiaphragmatic Technique in Patients with Suprasellar Extension: A Tertiary Center's Experience with Eleven Patient Cases

OBJECTIVE

As surgical techniques become less invasive, the use of endoscopy in brain surgery supports this trend. Numerous endoscopic surgical approaches have been defined, especially for skull base diseases. The current study summarizes our experience of using the rarely reported endoscopic transnasal transdiaphragmatic approach through the existing hole in the diaphragma sella to access lesions extending into the suprasellar region.

METHODS

Our surgical team performed 4876 endoscopic endonasal surgeries between August 1997 and December 2022 at the Department of Neurosurgery, Pituitary Research Center, Faculty of Medicine, Kocaeli University. The study retrospectively analyzed data from 11 patients who had undergone endoscopic transnasal transdiaphragmatic surgery since January 2020. Preoperative and postoperative magnetic resonance imaging, pituitary function examination, and clinical observation were carried out.

RESULTS

The mean age of the patients was 31.1 ± 10.7 years and the female/male ratio was 6:5. Pathologic subtypes observed included breast cancer metastasis (n = 1), adrenocorticotropic hormone-secreting adenoma (n = 4), growth hormone-secreting adenoma (n = 3), craniopharyngioma (n = 2), and Rathke cleft cyst (n = 1). The mean postoperative hospital stay was 4.7 ± 1.1 days and none of the patients showed cerebrospinal fluid leakage during this period.

CONCLUSIONS

The endoscopic transnasal transdiaphragmatic approach may be considered an alternative to the conventional extended endoscopic transnasal approach in patients with lesions extending into the suprasellar region. The main strength of this method is that it facilitates suprasellar region access through a small dural incision and bone defect in the base of the skull. As a result, it also reduces the risk of postoperative cerebrospinal fluid leakage and associated complications.

Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Endoscopic Endonasal Approach to the Sellar and Parasellar Regions

Introduction  Surgery of the sellar and parasellar regions can be challenging due to the complexity of neurovascular relationships. The main goal of this study is to develop an educational resource to help trainees understand the pertinent anatomy and procedural steps of the endoscopic endonasal approaches (EEAs) to the sellar and parasellar regions. Methods  Ten formalin-fixed latex-injected specimens were dissected. Endoscopic endonasal transsphenoidal transsellar, transtuberculum-transplanum, and transcavernous approaches were performed by a neurosurgery trainee, under supervision from the senior authors and a PhD in anatomy with advanced neuroanatomy experience. Dissections were supplemented with representative case applications. Results  Endoscopic endonasal transsphenoidal approaches afford excellent direct access to sellar and parasellar regions. After a wide sphenoidotomy, a limited sellar osteotomy opens the space to sellar region and medial portion of the cavernous sinus. To reach the suprasellar space (infrachiasmatic and suprachiasmatic corridors), a transplanum-prechiasmatic sulcus-transtuberculum adjunct is needed. The transcavernous approach gains access to the contents of the cavernous sinus and both medial (posterior clinoid and interpeduncular cistern) and lateral structures of the retrosellar region. Conclusion  The anatomical understanding and technical skills required to confidently remove skull base lesions with EEAs are traditionally gained after years of specialized training. We comprehensively describe EEAs to sellar and parasellar regions for trainees to build knowledge and improve familiarity with these approaches and facilitate comprehension and learning in both the surgical anatomy laboratory and the operating room.

Endoscopic Endonasal Transplanum-Transtuberculum Approach for Pituitary Adenomas/PitNET: 25 Years of Experience

The role of the endoscopic transplanum-transtuberculum approach (ETTA) in the treatment of pituitary adenomas/PitNETs (PAs) is sparsely analyzed in the literature, and its use is still debated in the current practice. The aim of this study was to report our experience with this approach. Our institutional registry was retrospectively reviewed, and patients who underwent ETTA for a PA from 1998 to 2022 were included. Fifty-seven cases were enrolled over a time span of 25 years, corresponding to 2.4% of our entire PA caseload. Radical resection was achieved in 57.9% of cases, with re-do surgery (p = 0.033) and vessel encasement/engulfment (p < 0.001) as predictors of partial resection. CSF leak incidence stood at 8.8%, with higher BMI (p = 0.038) as its only significant predictor. Partial or full improvement of the visual field deficits was achieved in 73.5% of cases. No surgical mortality was observed. According to our results, ETTA for the treatment of PAs is characterized by a satisfactory surgical outcome but with greater morbidity than the conventional endoscopic approach. Therefore, it should be reserved for the few selected cases otherwise unsuitable for the endoscopic trans-sphenoidal route, representing a valid alternative and an effective complementary route for the transcranial approach for these challenging PAs.

Antibiotics Prophylaxis for Endoscopic Endonasal Approach for Skull Base Tumor Surgery: A Meta-Analysis

BACKGROUND

The regimen of prophylactic antibiotic for endoscopic endonasal skull base surgery (EE-SBS) varies considerably depending on surgeons and their institutes. The purpose of the present meta-analysis is to assess the effect of antibiotic regimens on EE-SBS surgery for anterior skull base tumor.

METHODS

The PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched through October 15, 2022.

RESULTS

The 20 included studies were all retrospective. The studies included a total of 10,735 patients who underwent EE-SBS for skull base tumor. The proportion of patients with postoperative intracranial infection across all 20 studies was 0.9% (95% confidence interval [CI] 0.5%-1.3%). The proportion of postoperative intracranial infection in the multiple antibiotics group did not show statistically significant difference to that of the single antibiotic agent group (proportion: 0.6%, 95% CI 0%-1.4% vs. proportion: 1%, 95% CI 0.6%-1.5%, respectively, P = 0.39). The ultra-short duration maintenance group showed lower incidence of postoperative intracranial infection, although it did not reach statistical significance (ultra-short group: 0.7%, 95% CI 0.5%-0.9%; short duration: 1.8%, 95% CI 0.5%-3%; and long duration: 1%, 95% CI 0.2%-1.9%, P = 0.22) The combination of the multiple antibiotics group did not show meaningful low incidence of postoperative intracranial infection (antibiotics combination group: 0.6%, 95% CI 0%-1.4%; cefazolin single group: 0.8%, 95% CI 0%-1.6%; and single antibiotics other than cefazolin: 1.2%, 95% CI 0.7%-1.7%, P = 0.22).

CONCLUSIONS

Multiple antibiotics did not show superiority compared with single antibiotic agent. Also, long maintenance duration of antibiotics did not reduce the incidence of postoperative intracranial infection.

Endoscopic Endonasal Skull Base Surgery Complication Avoidance: A Contemporary Review

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

Endoscopic endonasal surgical anatomy through the prechiasmatic sulcus: the key window to suprachiasmatic and infrachiasmatic corridors

BACKGROUND

Classically, the transtuberculum and transplanum approaches have been utilized to reach the suprachiasmatic and infrachiasmatic corridors. The aim of this study was to provide a better understanding of the key endoscopic endonasal anatomy of the suprachiasmatic and infrachiasmatic corridors provided through selective removal of the prechiasmatic sulcus (SRPS).

METHOD

A SRPS was performed in 16 sides of 8 alcohol-fixed head specimens. Twenty anatomical measurements were collected on the suprachiasmatic and infrachiasmatic corridors. The transplanum and transtuberculum approaches were also performed.

RESULTS

In the suprachiasmatic corridor, the SRPS exposed the anterior communicating artery (AComm) and the post-communicating segment of the anterior cerebral arteries in all the cases, while the pre-communicating segment of the anterior cerebral arteries, recurrent arteries of Heubner, and fronto-orbital arteries were visualized in 75% (12/16), 31% (5/16), and 69% (11/16) of cases, respectively. In the infrachiasmatic corridor, the ophthalmic segment of the internal carotid artery and superior hypophyseal arteries were always visible through the SRPS. The mean width and height of the prechiasmatic sulcus were 13.2 mm and 9.6 mm, respectively. The mean distances from the midpoint of the AComm to the anterior margin of the optic chiasm (OCh) was 5.3 mm. The mean width of the infrachiasmatic corridor was 12.3 mm at the level of the proximal margin of the ophthalmic segment of the internal carotid artery. The mean distances from the posterior superior limit of the pituitary stalk to the basilar tip and oculomotor nerve were 9.7 mm and 12.3 mm, respectively.

CONCLUSIONS

The SRPS provides access to the main neurovascular and cisternal surgical landmarks of the suprachiasmatic and infrachiasmatic corridors. This anatomical area constitutes the key part of the approach to the suprasellar area. To afford adequate surgical maneuverability, the transplanum or transtuberculum approaches are usually a necessary extension.

Pediatric pituitary adenomas are more aggressive, more likely to be hormone producing and are more difficult to cure than adult pituitary adenomas: case series and systematic literature review

PURPOSE

Pediatric pituitary adenomas (pPAs) are uncommon. Thus, their presentation and outcomes after treatment are less well-understood than those of pituitary adenomas in adulthood (aPAs).

METHODS

A retrospective chart review was conducted for all patients who underwent endoscopic endonasal transsphenoidal surgery (EETS) for pPA at NewYork-Presbyterian Hospital/Weill Cornell Medicine (NYP/WCM) from 2005-2020. Eleven patients were identified, and information pertaining to age, sex, adenoma characteristics, procedural details, and outcomes was reviewed. A systematic review of the literature was also performed to compare outcomes of EETS versus microscopic endonasal transsphenoidal surgery (METS) for pPA.

RESULTS

From 2005-2020, 11 patients underwent EETS for pPA at NYP/WCM. Mean age at operation was 14.9 ± 2.7 years, and 5 patients (45.5%) were male. 10 adenomas (90.9%) were hormone-producing. Of the functional adenomas, 8 (80.0%) were PRL-secreting and 2 (20.0%) were GH-secreting. Maximum adenoma diameter (MAD) ranged from 1.2-5.1 cm, with a median of 1.55 cm. Cavernous sinus invasion (CSI) occurred in 2 patients with macroprolactinoma. Gross total resection (GTR) was achieved in 10 (90.9%). Biochemical remission occurred in 5/10 (50.0%). Post-operative complications were documented in 8 cases (72.7%) and included diabetes insipidus, hypopituitarism, sinusitis, weight gain, cerebrospinal fluid leak, meningitis, and hydrocephalus. Systematic literature review of 105 microscopic and 175 endoscopic cases revealed high frequency of hormone-producing tumors (83.6%) and similar rates of GTR (82.4% vs 85.1%) and biochemical cure (75.8% vs 64.3%).

CONCLUSIONS

pPAs are more likely to be hormone producing and may be more aggressive and difficult to cure than aPAs. EETS is an effective treatment, although complication rates may be higher than in adult populations.

Soft Gasket Seal Reconstruction after Endoscopic Endonasal Transtuberculum Resection of Craniopharyngiomas

BACKGROUND

The expanded endoscopic endonasal approach (EEA) is currently well-accepted for a variety of ventral skull base tumors. Such approach often results in a trans-dural defect and intraoperative cerebrospinal fluid (CSF) leak and adequate reconstruction is necessary to prevent postoperative CSF leak and its complications. Reconstruction is usually performed utilizing a variety of materials along with the nasoseptal flap (NSF).

OBJECTIVE

This work's aim is to describe a new reconstructive technique called 'Soft Gasket Seal' (SGS) in detail and compare it with the standard reconstructive technique at our institution for craniopharyngiomas operated via transtuberculum EEA.

METHODS

A retrospective chart review was achieved to identify patients who underwent transtubercular EEA for craniopharyngioma between 2010 and 2018, by the same neurosurgical and otolaryngology team using either the SGS or the standard reconstructive technique.

RESULTS

Of 36 patients who met criteria and were considered for analysis, 15 patients underwent the Soft Gasket Seal reconstruction and 21, the standard reconstruction. There were 16 female (44%) and 20 male (56%) patients. The median age was 42.2±20.9 years. The rate of postoperative CSF leak in the group of patients treated with the standard technique was 14.2%, and 6.6% in the SGS group (OR 0.43 [CI 95% 0.007 - 6.15, p = 0.62).

CONCLUSION

The SGS technique provides a simple reconstructive technique in conjunction with the NSF, showing a tendency of lower complications when compared to our standard technique, while avoiding donor site morbidity. Such results are encouraging, but further studies are necessary to confirm these findings.

The incidence of postoperative cerebrospinal fluid leakage after elective cranial surgery: a systematic review

Cerebrospinal fluid (CSF) leakage is a major complication after elective neurosurgical procedures. The aim of this systematic literature review is to summarize the incidence rates of postoperative cerebrospinal fluid leakage for neurosurgical procedures, classified by surgical approach. The Pubmed, Cochrane, Embase, and Web of Science databases were searched for studies reporting the outcome of patients undergoing elective neurosurgical procedures. The number of patients, surgical approach, and indication for surgery were recorded for each study. Outcomes related to CSF leakage such as clinical manifestation and treatment were reported as well. One hundred and thirteen studies were included, reporting 94,695 cases. Overall, CSF leaks were present in 3.8% of cases. Skull base surgery had the highest rate of CSF leakage with 6.2%. CSF leakage occurred in 5.9% of anterior skull base procedures, 6.4% of middle fossa, and 5.2% of transpetrosal surgeries. 5.8% of reported infratentorial procedures were complicated by CSF leakage versus 2.9% of supratentorial surgeries. CSF leakage remains a common serious adverse event after cranial surgery. There exists a need for standardized procedures to reduce the incidence of postoperative CSF leakage, as this serious adverse event may lead to increased health care costs.

Unilateral Subfrontal Approach for Giant Tuberculum Sellae Meningioma: Single Center Experience and Review of the Literature

Background

Microsurgical Transcranial approach (mTCA) is the primary choice for the resection of giant Tuberculum Sellae Meningiomas (TSM). The objective of this study is to explore surgical details of unilateral subfrontal approach.

Methods

Ten patients with giant TSM treated by unilateral subfrontal approach were included from January 2018 to June 2021. Demographic characteristics, surgical data, post-procedure complications and outcomes of patients have been descriptive analyzed, combined with systematic literature review to explore the surgical details and the prognosis of unilateral subfrontal approach.

Results

Ten patients include six male and four females, age range from 35 to 77 years, duration of visual impairment from 1 to 12 months, were all performed unilateral subfrontal approach. Nine patients achieved radical resection (Simpson grades I-II) through post-operative imaging confirmation, and Simpson IV resection was performed in the remaining one due to cavernous sinus invasion. The postoperative visual acuity was improved or maintained in 8 patients. Visual acuity decreased in 2 cases, including 1 case of optic nerve atrophy and the other case of optic canal not opening. Five cases with frontal sinus opened were repaired during the operation and there was no postoperative cerebrospinal fluid leakage or intracranial infection. One patient suffered from postoperative anosmia, one patient developed left limb weakness, but their symptoms have improved in the follow-up.

Conclusion

Summarize the experience of our center and previous literature, unilateral forehead bottom craniotomy is a feasible surgical approach for giant tuberculum sellae meningioma. Intraoperative application of EC glue and pedicled fascia flap to repair the frontal sinus can prevent complications associated with frontal sinus opening. Optic canal unroofing has huge advantage in visual improvement.

Complications after 1002 endoscopic endonasal approach procedures at a single center: lessons learned, 2010-2018

OBJECTIVE

The endoscopic endonasal approach (EEA) has evolved into a mainstay of skull base surgery over the last two decades, but publications examining the intraoperative and perioperative complications of this technique remain scarce. A prior landmark series of 800 patients reported complications during the first era of EEA (1998-2007), parallel to the development of many now-routine techniques and technologies. The authors examined a single-institution series of more than 1000 consecutive EEA neurosurgical procedures performed since 2010, to elucidate the safety and risk factors associated with surgical and postoperative complications in this modern era.

METHODS

After obtaining institutional review board approval, the authors retrospectively reviewed intraoperative and postoperative complications and their outcomes in patients who underwent EEA between July 2010 and June 2018 at a single institution.

RESULTS

The authors identified 1002 EEA operations that met the inclusion criteria. Pituitary adenoma was the most common pathology (n = 392 [39%]), followed by meningioma (n = 109 [11%]). No patients died intraoperatively. Two (0.2%) patients had an intraoperative carotid artery injury: 1 had no neurological sequelae, and 1 had permanent hemiplegia. Sixty-one (6.1%) cases of postoperative cerebrospinal fluid leak occurred, of which 45 occurred during the original surgical hospitalization. Transient postoperative sodium dysregulation was noted after 87 (8.7%) operations. Six (0.6%) patients were treated for meningitis, and 1 (0.1%) patient died of a fungal skull base infection. Three (0.3%) patients died of medical complications, thereby yielding a perioperative 90-day mortality rate of 0.4% (4 deaths). High-grade (Clavien-Dindo grade III-V) complications were identified after 103 (10%) EEA procedures, and multivariate analysis was performed to determine the associations between factors and these more serious complications. Extradural EEA was significantly associated with decreased rates of these high-grade complications (OR [95% CI] 0.323 [0.153-0.698], p = 0.0039), whereas meningioma pathology (OR [95% CI] 2.39 [1.30-4.40], p = 0.0053), expanded-approach intradural surgery (OR [95% CI] 2.54 [1.46-4.42], p = 0.0009), and chordoma pathology (OR [95% CI] 9.31 [3.87-22.4], p < 0.0001) were independently associated with significantly increased rates of high-grade complications.

CONCLUSIONS

The authors have reported a large 1002-operation cohort of EEA procedures and associated complications. Modern EEA surgery for skull base pathologies has an acceptable safety profile with low morbidity and mortality rates. Nevertheless, significant intraoperative and postoperative complications were correlated with complex intradural procedures and meningioma and chordoma pathologies.

Endoscopic technology and repair techniques

In this chapter, we describe advances in endoscopic endonasal surgery that have impacted skull base meningioma surgery. After reviewing the technical innovations in endoscopy, we describe the advances as they relate to each surgical step. We discuss preoperative planning and approach and the utility of neuronavigation and neuromonitoring. We then discuss endoscopic instrumentation, technology for tumor debulking (ultrasonic aspirators, radiofrequency ablators, suction debriders), and hemostatic agents as they relate to tumor resection and hemostasis. In the end, we discuss techniques of skull base reconstruction and closure (nasoseptal flap, gasket seal and bilayer button).

A Review of Common Endoscopic Intracranial Approaches

With the evolution of surgical techniques, endoscopy has emerged as a suitable alternative to many instances of more invasive methods. In this review article, we aim to discuss the endoscopic advancements, procedural details, indications, and outcomes of the most commonly practiced neuroendoscopic procedures. We have also summarized the uses, techniques, and challenges of neuroendoscopy in select neurosurgical pathologies.

Arachnoid prolapse in endoscopic transsphenoidal surgery of pituitary adenoma, technical note

PURPOSE

An arachnoid prolapse after endoscopic transsphenoidal surgery for a pituitary adenoma is an uncommon, but important, phenomenon which should be managed. We have evaluated the efficacy of a new simple technique to correct the prolapsed arachnoid following endoscopic surgery of pituitary adenomas.

METHODS

A total of 1352 patients with pituitary adenomas, 24-76 years old, who underwent full endoscopic transsphenoidal surgeries between February 2014 and February 2019 in Erfan and Loghman Hakim hospitals. 46 patients with arachnoid prolapse participated in this study and41 patients completed the study. Arachnoid prolapse was repaired by bipolar cauterization with either autologous fat grafts (36 patients) or without autologous fat grafts (5patients).

RESULTS

Of 41 patients who completed the study, all except one, had large adenomas with significant suprasellar extension and enlarged diaphragma sellae. All patients had arachnoid prolapse at the end of the tumor removal stage and 13 patients had very minor intraoperative CSF leakage. Prolapsed arachnoid was repaired using a bipolar cautery with or without the autologous fat graft. During the postoperative follow-up period, none of the patient experienced early or delayed postoperative CSF leakage, meningitis, visual deterioration, delayed epistaxis, cranial nerve palsy, recurrence, or death.

CONCLUSION

Bipolar cauterization is a safe, effective technique to repair a suprasellar arachnoid prolapse during reconstruction of the sellar floor following endoscopic transsphenoidal pituitary surgery.

ICAR: endoscopic skull-base surgery

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Surgical management of craniopharyngiomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section

BACKGROUND AND OBJECTIVE

Craniopharyngiomas are locally aggressive neuroepithelial tumors infiltrating nearby critical neurovascular structures. The majority of published surgical series deal with childhood-onset craniopharyngiomas, while the optimal surgical management for adult-onset tumors remains unclear. The aim of this paper is to summarize the main principles defining the surgical strategy for the management of craniopharyngiomas in adult patients through an extensive systematic literature review in order to formulate a series of recommendations.

MATERIAL AND METHODS

The MEDLINE database was systematically reviewed (January 1970-February 2019) to identify pertinent articles dealing with the surgical management of adult-onset craniopharyngiomas. A summary of literature evidence was proposed after discussion within the EANS skull base section.

RESULTS

The EANS task force formulated 13 recommendations and 4 suggestions. Treatment of these patients should be performed in tertiary referral centers. The endonasal approach is presently recommended for midline craniopharyngiomas because of the improved GTR and superior endocrinological and visual outcomes. The rate of CSF leak has strongly diminished with the use of the multilayer reconstruction technique. Transcranial approaches are recommended for tumors presenting lateral extensions or purely intraventricular. Independent of the technique, a maximal but hypothalamic-sparing resection should be performed to limit the occurrence of postoperative hypothalamic syndromes and metabolic complications. Similar principles should also be applied for tumor recurrences. Radiotherapy or intracystic agents are alternative treatments when no further surgery is possible. A multidisciplinary long-term follow-up is necessary.

Acellular dermal matrix as an alternative to autologous fascia lata for skull base repair following extended endoscopic endonasal approaches

BACKGROUND

Skull base reconstruction after extended endoscopic endonasal approaches (EEAs) can be challenging. In addition to the nasoseptal flap, which has been adopted by most centers, autologous fascia lata is also often utilized. Harvesting of fascia lata requires a separate thigh incision, may prolong recovery, and results in a visible scar. In principal, the use of non-autologous materials would be preferable to avoid a second incision and maintain the minimally invasive nature of the approach, assuming the CSF leak rate is not compromised.

OBJECTIVE

To assess the efficacy of acellular dermal matrix (ADM) as a non-autologous alternative to autologous fascia lata graft for watertight closure of the cranial base following EEAs.

METHODS

A retrospective chart review of extended EEAs performed before and after the transition from fascia lata to ADM was performed. Cases were frequency matched for approach, pathology, BMI, use of lumbar drainage, and tumor volume. Power analysis was performed to estimate the sample size needed to demonstrate non-inferiority.

RESULTS

ADM was used for watertight closure of the cranial base in 19 consecutive extended endoscopic endonasal approaches (16 gasket-seals and 3 buttons) with 1 postoperative CSF leak at the last follow-up (median 5.3, range 1.0-12.6 months). All patients had high-flow intraoperative leaks. The cohort included 8 meningiomas, 8 craniopharyngiomas, 2 chordomas, and 1 pituicytoma ranging in size from 0.2 to 37.2cm³ (median 5.5, IQR 2.8-13.3 cm³). In 19 historical controls who received fascia lata, there were 2 postoperative CSF leaks.

CONCLUSIONS

Preliminary results suggest that ADM provides a non-inferior non-autologous alternative to fascia lata for watertight gasket-seal and button closures following extended EEAs, potentially reducing or eliminating the need to harvest autologous tissue.

How long is the tail end of the learning curve? Results from 1000 consecutive endoscopic endonasal skull base cases following the initial 200 cases

OBJECTIVE

Endoscopic endonasal approaches (EEAs) to the skull base have evolved over the last 20 years to become an essential component of a comprehensive skull base practice. Many case series show a learning curve from the earliest cases, in which the authors were inexperienced or were not using advanced closure techniques. It is generally accepted that once this learning curve is achieved, a plateau is reached with little incremental improvement. Cases performed during the early steep learning curve were eliminated to examine whether the continued improvement exists over the "tail end" of the curve.

METHODS

A prospectively acquired database of all EEA cases performed by the senior authors at Weill Cornell Medicine/NewYork-Presbyterian Hospital was reviewed. The first 200 cases were eliminated and the next 1000 consecutive cases were examined to avoid the bias created by the early learning curve.

RESULTS

Of the 1000 cases, the most common pathologies included pituitary adenoma (51%), meningoencephalocele or CSF leak repair (8.6%), meningioma (8.4%), craniopharyngioma (7.3%), basilar invagination (3.1%), Rathke's cleft cyst (2.8%), and chordoma (2.4%). Use of lumbar drains decreased from the first half to the second half of our series (p <0.05) as did the authors' use of fat alone (p <0.005) or gasket alone (p <0.005) for dural closure, while the use of a nasoseptal flap increased (p <0.005). Although mean tumor diameter was constant (on average), gross-total resection (GTR) increased from 60% in the first half to 73% in the second half (p <0.005). GTR increased for all pathologies but most significantly for chordoma (56% vs 100%, p <0.05), craniopharyngioma (47% vs 0.71%, p <0.05) and pituitary adenoma (67% vs 75%, p <0.05). Hormonal cure for secreting adenomas also increased from 83% in the first half to 89% in the second half (p <0.05). The rate of any complication was unchanged at 6.4% in the first half and 6.2% in the latter half of cases, and vascular injury occurred in only 0.6% of cases. Postoperative CSF leak occurred in 2% of cases and was unchanged between the first and second half of the series.

CONCLUSIONS

This study demonstrates that contrary to popular belief, the surgical learning curve does not plateau but can continue for several years depending on the complexity of the endpoints considered. These findings may have implications for clinical trial design, surgical education, and patient safety measures.

Three-Hand Endoscopic Endonasal Transsphenoidal Surgery: Experience With an Anatomy-Preserving Mononostril Approach Technique

BACKGROUND

Variations on the endoscopic transsphenoidal approach present unique surgical techniques that have unique effects on surgical outcomes, extent of resection (EOR), and anatomical complications.

OBJECTIVE

To analyze the learning curve and perioperative outcomes of the 3-hand endoscopic endonasal mononostril transsphenoidal technique.

METHODS

Prospective case series and retrospective data analysis of patients who were treated with the 3-hand transsphenoidal technique between January 2007 and May 2015 by a single neurosurgeon. Patient characteristics, preoperative presentation, tumor characteristics, operative times, learning curve, and postoperative outcomes were analyzed. Volumetric EOR was evaluated, and a logistic regression analysis was used to assess predictors of EOR.

RESULTS

Two hundred seventy-five patients underwent an endoscopic transsphenoidal surgery using the 3-hand technique. One hundred eighteen patients in the early group had surgery between 2007 and 2010, while 157 patients in the late group had surgery between 2011 and 2015. Operative time was significantly shorter in the late group (161.6 min) compared to the early group (211.3 min, P = .001). Both cohorts had similar EOR (early group 84.6% vs late group 85.5%, P = .846) and postoperative outcomes. The learning curve showed that it took 54 cases to achieve operative proficiency with the 3-handed technique. Multivariate modeling suggested that prior resections and preoperative tumor size are important predictors for EOR.

CONCLUSION

We describe a 3-hand, mononostril endoscopic transsphenoidal technique performed by a single neurosurgeon that has minimal anatomic distortion and postoperative complications. During the learning curve of this technique, operative time can significantly decrease, while EOR, postoperative outcomes, and complications are not jeopardized.

3D printing and intraoperative neuronavigation tailoring for skull base reconstruction after extended endoscopic endonasal surgery: proof of concept

OBJECTIVE

Endoscopic endonasal approaches are increasingly performed for the surgical treatment of multiple skull base pathologies. Preventing postoperative CSF leaks remains a major challenge, particularly in extended approaches. In this study, the authors assessed the potential use of modern multimaterial 3D printing and neuronavigation to help model these extended defects and develop specifically tailored prostheses for reconstructive purposes.

METHODS

Extended endoscopic endonasal skull base approaches were performed on 3 human cadaveric heads. Pre-Preprocedure and intraprocedure CT scans were completed and were used to segment and design extended and tailored skull base models. Multimaterial models with different core/edge interfaces were 3D printed for implantation trials. A novel application of the intraoperative landmark acquisition method was used to transfer the navigation, helping to tailor the extended models.

RESULTS

Prostheses were created based on preoperative and intraoperative CT scans. The navigation transfer offered sufficiently accurate data to tailor the preprinted extended skull base defect prostheses. Successful implantation of the skull base prostheses was achieved in all specimens. The progressive flexibility gradient of the models’ edges offered the best compromise for easy intranasal maneuverability, anchoring, and structural stability. Prostheses printed based on intraprocedure CT scans were accurate in shape but slightly undersized.

CONCLUSIONS

Preoperative 3D printing of patient-specific skull base models is achievable for extended endoscopic endonasal surgery. The careful spatial modeling and the use of a flexibility gradient in the design helped achieve the most stable reconstruction. Neuronavigation can help tailor preprinted prostheses.

Endoscopic reconstruction of large anterior skull base defects with opening of the sellar diaphragm. Experience at a tertiary level university hospital

Background

The indications for expanded endoscopic transnasal approaches continue to increase, with more complex skull base defects needing to be repaired. This study reviews the management of large anterior skull base defects with opening of the sellar diaphragm.

Method

A prospective analysis of endonasal endoscopic surgery carried out at Son Espases University Hospital between January 2013 and December 2018 was performed. The analysis included only the cases with a significative intra-operative cerebrospinal fluid leak. In all cases, reconstruction was performed by combining the gasket seal technique with a pedicled mucosal endonasal flap.

Results

Twenty-eight patients were included. The mucoperiosteal nasoseptal flap, the lateral wall flap and the middle turbinate flap were used in 13, 8 and 7 patients, respectively, combined with the gasket seal technique. One case of post-operative cerebrospinal fluid leak was observed (3.57 per cent).

Conclusion

The combination of a gasket seal with an endonasal mucosal flap is an excellent technique for repairing large anterior skull base defects.

Endonasal surgery for suprasellar germ cell tumors: two cases and review of the literature

Germ cell tumors are rare malignant tumors frequently located in the suprasellar region. Definitive treatment is chemotherapy and radiation. However, in some circumstances, surgery is indicated for biopsy or resection. There are limited reports of the role of the endonasal endoscopic approach (EEA) in the management of this tumor. We present two cases in which EEA was utilized for successful management of germ cell tumor. The most challenging aspect of germ cell tumor management for the treating physician is knowing the proper indications for surgery. In this paper, we highlight two specific instances, namely diagnosis and tumor refractory to chemoradiation. Given the suprasellar location, EEA is an ideal approach.

Anterior communicating artery division in the endoscopic endonasal translamina terminalis approach to the third ventricle: an anatomical feasibility study

BACKGROUND

Endonasal endoscopic approaches (EEA) to the third ventricle are well described but generally use an infrachiasmatic route since the suprachiasmatic translamina terminalis corridor is blocked by the anterior communicating artery (AComA). The bifrontal basal interhemispheric translamina terminalis approach has been facilitated with transection of the AComA. The aim of the study is to describe the anatomical feasibility and limitations of the EEA translamina terminalis approach to the third ventricle augmented with AComA surgical ligation.

METHODS

Endoscopic dissections were performed on five cadaveric heads injected with colored latex using rod lens endoscopes attached to a high-definition camera and a digital video recorder system. A stepwise anatomical dissection of the endoscopic endonasal transtuberculum, transplanum, translamina terminalis approach to the third ventricle was performed. Measurements were performed before and after AComA elevation and transection using a millimeter flexible caliper.

RESULTS

Multiple comparison statistical analysis revealed a statistically significant difference in vertical exposure between the control condition and after AComA elevation, between the control condition and after AComA division and between the AComA elevation and division (p < 0.05). The mean difference in exposed surgical area was statistically significant between the control and after AComA division and between elevation and AComA division (p < 0.01), whereas it was not statistically significant between the control condition and AComA elevation (NS).

CONCLUSION

The anatomical feasibility of clipping and dividing the AComA through an EEA has been demonstrated in all the cadaveric specimens. The approach facilitates exposure of the suprachiasmatic optic recess within the third ventricle that may be a blind spot during an infrachiasmatic approach.

Does lumbar drainage reduce postoperative cerebrospinal fluid leak after endoscopic endonasal skull base surgery? A prospective, randomized controlled trial

OBJECTIVE

Based on a null hypothesis that the use of short-term lumbar drainage (LD) after endoscopic endonasal surgery (EES) for intradural pathology does not prevent postoperative CSF leaks, a trial was conducted to assess the effect of postoperative LD on postoperative CSF leak following standard reconstruction.

METHODS

A prospective, randomized controlled trial of lumbar drain placement after endoscopic endonasal skull base surgery was performed from February 2011 to March 2015. All patients had 3-month follow-up data. Surgeons were blinded to which patients would or would not receive the drain until after closure was completed. An a priori power analysis calculation assuming 80% of power, 5% postoperative CSF leak rate in the no-LD group, and 16% in the LD group determined a planned sample size of 186 patients. A routine data and safety check was performed with every 50 patients being recruited to ensure the efficacy of randomization and safety. These interim tests were run by a statistician who was not blinded to the arms they were evaluating. This study accrued 230 consecutive adult patients with skull base pathology who were eligible for endoscopic endonasal resection. Inclusion criteria (high-flow leak) were dural defect greater than 1 cm2 (mandatory), extensive arachnoid dissection, and/or dissection into a ventricle or cistern. Sixty patients were excluded because they did not meet the inclusion criteria. One hundred seventy patients were randomized to either receive or not receive a lumbar drain.

RESULTS

One hundred seventy patients were randomized, with a mean age of 51.6 years (range 19-86 years) and 38% were male. The mean BMI for the entire cohort was 28.1 kg/m2. The experimental cohort with postoperative LD had an 8.2% rate of CSF leak compared to a 21.2% rate in the control group (odds ratio 3.0, 95% confidence interval 1.2-7.6, p = 0.017). In 106 patients in whom defect size was measured intraoperatively, a larger defect was associated with postoperative CSF leak (6.2 vs 2.9 cm2, p = 0.03). No significant difference was identified in BMI between those with (mean 28.4 ± 4.3 kg/m2) and without (mean 28.1 ± 5.6 kg/m2) postoperative CSF leak (p = 0.79). Furthermore, when patients were grouped based on BMI < 25, 25-29.9, and > 30 kg/m2, no difference was noted in the rates of CSF fistula (p = 0.97).

CONCLUSIONS

Among patients undergoing intradural EES judged to be at high risk for CSF leak as defined by the study's inclusion criteria, perioperative LD used in the context of vascularized nasoseptal flap closure significantly reduced the rate of postoperative CSF leaks.Clinical trial registration no.: NCT03163134 (clinicaltrials.gov).

The posterior nasoseptal flap: A novel technique for closure after endoscopic transsphenoidal resection of pituitary adenomas

Background:

While effective for the repair of large skull base defects, the Hadad-Bassagasteguy nasoseptal flap increases operative time and can result in a several-week period of postoperative crusting during re-mucosalization of the denuded nasal septum. Endoscopic transsphenoidal surgery for pituitary adenoma resection is generally not associated with large dural defects and high-flow cerebrospinal fluid (CSF) leaks requiring extensive reconstruction. Here, we present the posterior nasoseptal flap as a novel technique for closure of skull defects following endoscopic resection of pituitary adenomas. This flap is raised in all surgeries during the transnasal exposure using septal mucoperiosteum that would otherwise be discarded during the posterior septectomy performed in binostril approaches.

Methods:

We present a retrospective, consecutive case series of 43 patients undergoing endoscopic transsphenoidal resection of a pituitary adenoma followed by posterior nasoseptal flap placement and closure. Main outcome measures were extent of resection and postoperative CSF leak.

Results:

The mean extent of resection was 97.16 ± 1.03%. Radiographic measurement showed flap length to be adequate. While a defect in the diaphragma sellae and CSF leak were identified in 21 patients during surgery, postoperative CSF leak occurred in only one patient.

Conclusions:

The posterior nasoseptal flap provides adequate coverage of the surgical defect and is nearly always successful in preventing postoperative CSF leak following endoscopic transsphenoidal resection of pituitary adenomas. The flap is raised from mucoperiosteum lining the posterior nasal septum, which is otherwise resected during posterior septectomy. Because the anterior septal cartilage is not denuded, raising such flaps avoids the postoperative morbidity associated with the larger Hadad-Bassagasteguy nasoseptal flap.

Suprasellar and recurrent pediatric craniopharyngiomas: expanding indications for the extended endoscopic transsphenoidal approach

OBJECTIVE The expanded endonasal endoscopic transsphenoidal approach has become increasingly used for craniopharyngioma surgery in the pediatric population, but questions still persist regarding its utility in younger children, in recurrent and irradiated tumors, and in masses primarily located in the suprasellar region. The narrow corridor, incomplete pneumatization, and fear of hypothalamic injury have traditionally relegated this approach to application in older children with mostly cystic craniopharyngiomas centered in the sella. The authors present a series of consecutive pediatric patients in whom the endonasal endoscopic approach was used to remove craniopharyngiomas from patients of varied ages, regardless of the location of the tumor and previous treatments or surgeries, to ascertain if the traditional concerns about limitations of this approach are worth reevaluating METHODS Eleven consecutive pediatric patients (age ≤ 18 years) underwent surgery via an endoscopic transsphenoidal approach at NewYork-Presbyterian/Weill Cornell Medical Center from 2007 to 2016. The authors recorded the location, consistency, and size of the lesion, assessed for hypothalamic invasion radiographically, calculated skull base measurements, and assessed parameters such as extent of resection, visual function, endocrinological function, weight gain, and return-to-school status. RESULTS The average age at the time of surgery was 7.9 years (range 4-17 years) and the tumor sizes ranged from 1.3 to 41.7 cm³. Five cases were purely suprasellar, 5 had solid components, 4 were reoperations, and 5 had a conchal sphenoid aeration. Nevertheless, gross-total resection was achieved in 45% of the patients and 50% of those in whom it was the goal of surgery, without any correlation with the location, tumor consistency, or the age of the patient. Near-total resection, subtotal resection, or biopsy was performed intentionally in the remaining patients to avoid hypothalamic injury. Anterior pituitary dysfunction occurred in 81.8% of the patients, and 63.3% developed diabetes insipidus . Two patients (18%) had a greater than 9% increase in body mass index. Visual function was stable or improved in 73%. All children returned to an academic environment, with 10 of them in the grade appropriate for their age. There was a single case of each of the following: CSF leak, loss of vision unilaterally, and abscess. CONCLUSIONS The endoscopic transsphenoidal approach is suitable for removing pediatric craniopharyngiomas even in young children with suprasellar tumors, conchal sphenoid sinus, recurrent tumors, and tumors with solid components. The extent of resection is dictated by intrinsic hypothalamic tumor invasiveness rather than the approach. The endoscopic transsphenoidal approach affords the ability to directly inspect the hypothalamus to determine invasion, which may help spare the patient from hypothalamic injury. Irrespective of approach, the rates of postoperative endocrinopathy remain high and the learning curve for the approach to a relatively rare tumor is steep.

Is the chiasm-pituitary corridor size important for achieving gross-total resection during endonasal endoscopic resection of craniopharyngiomas?

OBJECTIVE Craniopharyngiomas arise from the pituitary stalk, and in adults they are generally located posterior to the chiasm extending up into the third ventricle. The extended endonasal approach (EEA) can provide an ideal corridor between the bottom of the optic chiasm and the top of the pituitary gland (chiasm-pituitary corridor [CPC]) for their removal. A narrow CPC in patients with a prefixed chiasm and a large tumor extending up and behind the chiasm has been considered a contraindication to EEA, with a high risk of visual deterioration and subtotal resection. METHODS A database of all patients treated in the authors' center (Weill Cornell Medical College, NewYork-Presbyterian Hospital) between July 2004 and August 2016 was reviewed. Patients with craniopharyngiomas who underwent EEA with the goal of gross-total resection (GTR) were included in the study. Patients with postfixed chiasm or limited available preoperative imaging were excluded. Using preoperative contrast-enhanced T1-weighted sagittal midline MR images, the authors calculated the CPC as well as the distance from the chiasm to the top of the tumor (CTOT). From these numbers, they calculated a ratio of the CPC to the CTOT as a measure of difficulty in removing the tumors through the EEA and called this ratio the corridor index (CI). The relationship between the CI and the ability to achieve GTR and visual outcome were measured. RESULTS Thirty-four patients were included in the study. The mean CPC was 10.1 mm (range 5.2-19.1 mm). The mean CTOT was 12.8 mm (range 0-28.3 mm). The median CI was 0.8; the CI ranged from 0.4 to infinity (for tumors with a CTOT of 0). Thirty-two patients had GTR (94.1%) and 2 had subtotal resection. The CPC value had no relationship with our ability to achieve GTR and no effect on visual or endocrine outcome. CONCLUSIONS EEA for craniopharyngioma is generally considered the first-line surgical approach. Although a narrow corridor between the top of the pituitary gland and the bottom of the chiasm may seem to be a relative contraindication to surgery for larger tumors, the authors' data do not bear this out. EEA appears to be a successful technique for the majority of midline craniopharyngiomas.

Reoperative endoscopic endonasal surgery for residual or recurrent pituitary adenomas

OBJECTIVE

Regrowth of the lesion after surgical removal of pituitary adenomas is uncommon unless subtotal resection was originally achieved in the first surgery. Treatment for recurrent tumor can involve surgery or radiotherapy. Locations of residual tumor may vary based on the original approach. The authors evaluated the specific sites of residual or recurrent tumor after different transsphenoidal approaches and describe the surgical outcome of endoscopic endonasal transsphenoidal reoperation.

METHODS

The authors analyzed a prospectively collected database of a consecutive series of patients who had undergone endoscopic endonasal surgeries for residual or recurrent pituitary adenomas after an original transsphenoidal microscopic or endoscopic surgery. The site of the recurrent tumor and outcome after reoperation were noted and correlated with the primary surgical approach. The chi-square or Fisher exact test was used to compare categorical variables, and the Mann-Whitney U-test was used to compare continuous variables between surgical groups.

RESULTS

Forty-one patients underwent surgery for residual/recurrent pituitary adenoma from 2004 to 2015 at Weill Cornell Medical College. The previous treatment was a transsphenoidal microscopic (n = 22) and endoscopic endonasal (n = 19) surgery. In 83.3% patients (n = 30/36) there was postoperative residual tumor after the initial surgery. A residual tumor following endonasal endoscopic surgery was less common in the sphenoid sinus (10.5%; 2/19) than it was after microscopic transsphenoidal surgery (72.7%; n =16/22; p = 0.004). Gross-total resection (GTR) was achieved in 58.5%, and either GTR or near-total resection was achieved in 92.7%. Across all cases, the average extent of resection was 93.7%. The rate of GTR was lower in patients with Knosp-Steiner Grade 3–4 invasion (p < 0.0005). Postoperative CSF leak was seen in only one case (2.4%), which stopped with lumbar drainage. Visual fields improved in 52.9% (n = 9/17) of patients and were stable in 47% (n = 8/17). Endocrine remission was achieved in 77.8% (n = 14/18) of cases, 12 by surgery alone and 2 by adjuvant medical (n = 1) and radiation (n = 1) therapy. New diabetes insipidus occurred in 4.9% (n = 2/41) of patients—in one of whom an additional single anterior hormonal axis was compromised—and 9.7% (n = 4/41) of patients had a new anterior pituitary hormonal insufficiency.

CONCLUSIONS

Endonasal endoscopic reoperation is extremely effective at removing recurrent or residual pituitary adenomas that remain after a prior surgery, and it may be preferable to radiation therapy particularly in symptomatic patients. Achievement of GTR is less common when lateral cavernous sinus invasion is present. The locations of residual/recurrent tumor were more likely sphenoidal and parasellar following a prior microscopic transsphenoidal surgery and sellar following a prior endonasal endoscopic surgery.

Recurrent Pituicytoma with Pseudoaneurysm: Report of a Challenging Case

BACKGROUND

Pituicytoma is a rare tumor originating from glial cells of the adult neurohypophysis and infundibulum. Surgical removal is the treatment of choice for this neoplasm. In recent years the endoscopic endonasal approach has proven to be a viable and effective alternative to standard craniotomy.

CASE DESCRIPTION

We report a case of a patient submitted to surgical treatment for a recurrence of pituicytoma, which was operated on transcranially at another hospital approximately 5 years previously. After transcranial surgery, the patient developed a symptomatic recurrence and an undisclosed intrasellar pseudoaneurysm that were treated with an endoscopic endonasal approach, but still required an intracranial approach to complete the resection.

CONCLUSIONS

An intrasellar pseudoaneurysm can endanger the endoscopic removal of the pituicytoma, forcing the surgeon to reevaluate a microscopic transcranial approach or to consider a staged procedure.

Endonasal endoscopic pituitary surgery in the elderly

OBJECTIVE Pituitary adenomas are benign, slow-growing tumors that cause symptoms either through mass effect or hormone overproduction. The decision to operate on a healthy young person is relatively straightforward. In the elderly population, however, the risks of complications may increase, rendering the decision more complex. Few studies have documented the risks of surgery using the endonasal endoscopic approach in a large number of elderly patients. The purpose of this study was to audit a single center's data regarding outcomes of purely endoscopic endonasal transsphenoidal resection of pituitary adenomas in elderly patients and to compare them to the current literature. METHODS A retrospective review of a prospectively acquired database of all endonasal endoscopic surgeries done by the senior authors was queried for patients aged 60-69 years and for those aged 70 years or older. Demographic and radiographic preoperative data were reviewed. Outcomes with respect to extent of resection and complications were examined and compared with appropriate statistical tests. RESULTS A total of 135 patents were identified (81 aged 60-69 years and 54 aged 70 years or older [70+]). The average tumor diameter was slightly larger for the patients in the 70+ age group (mean [SD] 25.7 ± 9.2 mm) than for patients aged 60-69 years (23.1 ± 9.8 mm, p = 0.056). There was no significant difference in intraoperative blood loss (p > 0.99), length of stay (p = 0.22), or duration of follow-up (p = 0.21) between the 2 groups. There was a 7.4% complication rate in patients aged 60-69 years (3 nasal and 3 medical complications) and an 18.5% complication rate in patients older than 70 years (4 cranial, 3 nasal, 1 visual, and 2 medical complications; p = 0.05 overall and 0.013 for cranial complications). Cranial complications in the 70+ age category included 2 postoperative hematomas, 1 pseudoaneurysm formation, and 1 case of symptomatic subdural hygromas. CONCLUSIONS Endonasal endoscopic surgery in elderly patients is safe, but there is a graded increase in complication rates with increasing age. The decision to operate on an asymptomatic or mildly symptomatic patient in these age groups should take this increasing complication rate into account. The use of a lumbar drain or lumbar punctures should be weighed against the risk of subdural hematoma in patients with preexisting atrophy.

Anatomical nuances of the internal carotid artery in relation to the quadrangular space

OBJECTIVE The aim of this study was to evaluate the anatomical variations of the internal carotid artery (ICA) in relation to the quadrangular space (QS) and to propose a classification system based on the results. METHODS A total of 44 human cadaveric specimens were dissected endonasally under direct endoscopic visualization. During the dissection, the anatomical variations of the ICA and their relationship with the QS were noted. RESULTS The space between the paraclival ICAs (i.e., intercarotid space) can be classified as 1 of 3 different shapes (i.e., trapezoid, square, or hourglass) based on the trajectory of the ICAs. The ICA trajectories also directly influence the volumetric area of the QS. Based on its geometry, the QS was classified as one of the following: 1) Type A has the smallest QS area and is associated with a trapezoid intercarotid space, 2) Type B corresponds to the expected QS area (not minimized or enlarged) and is associated with a square intercarotid space, and 3) Type C has the largest QS area and is associated with an hourglass intercarotid space. CONCLUSIONS The different trajectories of the ICAs can modify the area of the QS and may be an essential parameter to consider for preoperative planning and defining the most appropriate corridor to reach Meckel's cave. In addition, ICA trajectories should be considered prior to surgery to avoid injuring the vessels.

Endoscopic endonasal versus transcranial approach to tuberculum sellae and planum sphenoidale meningiomas in a similar cohort of patients

OBJECTIVE Planum sphenoidale (PS) and tuberculum sellae (TS) meningiomas cause visual symptoms due to compression of the optic chiasm. The treatment of choice is surgical removal with the goal of improving vision and achieving complete tumor removal. Two options exist to remove these tumors: the transcranial approach (TCA) and the endonasal endoscopic approach (EEA). Significant controversy exists regarding which approach provides the best results and whether there is a subset of patients for whom an EEA may be more suitable. Comparisons using a similar cohort of patients, namely, those suitable for gross-total resection with EEA, are lacking from the literature. METHODS The authors reviewed all cases of PS and TS meningiomas that were surgically removed at Weill Cornell Medical College between 2000 and 2015 (TCA) and 2008 and 2015 (EEA). All cases were shown to a panel of 3 neurosurgeons to find only those tumors that could be removed equally well either through an EEA or TCA to standardize both groups. Volumetric measurements of preoperative and postoperative tumor size, FLAIR images, and apparent diffusion coefficient maps were assessed by 2 independent reviewers and compared to assess extent of resection and trauma to the surrounding brain. Visual outcome and complications were also compared. RESULTS Thirty-two patients were identified who underwent either EEA (n = 17) or TCA (n = 15). The preoperative tumor size was comparable (mean 5.58 ± 3.42 vs 5.04 ± 3.38 cm³ [± SD], p = 0.661). The average extent of resection achieved was not significantly different between the 2 groups (98.80% ± 3.32% vs 95.13% ± 11.69%, p = 0.206). Postoperatively, the TCA group demonstrated a significant increase in the FLAIR/edema signal compared with EEA patients (4.15 ± 7.10 vs -0.69 ± 2.73 cm³, p = 0.014). In addition, the postoperative diffusion-weighted imaging signal of cytotoxic ischemic damage was significantly higher in the TCA group than in the EEA group (1.88 ± 1.96 vs 0.40 ± 0.55 cm³, p =0.008). Overall, significantly more EEA patients experienced improved or stable visual outcomes compared with TCA patients (93% vs 56%, p = 0.049). Visual deterioration was greater after TCA than EEA (44% vs 0%, p = 0.012). While more patients experienced postoperative seizures after TCA than after EEA (27% vs 0%, p = 0.038), there was a trend toward more CSF leakage and anosmia after EEA than after TCA (11.8% vs 0%, p = 0.486 and 11.8% vs 0%, p = 0.118, respectively). CONCLUSIONS In this small single-institution study of similarly sized and located PS and TS meningiomas, EEA provided equivalent rates of resection with better visual results, less trauma to the brain, and fewer seizures. These preliminary results merit further investigation in a larger multiinstitutional study and may support EEA resection by experienced surgeons in a subset of carefully selected PS and TS meningiomas.

Endoscopic Endonasal Management of Craniopharyngioma

Craniopharyngioma is a rare clinical entity that poses a significant management challenge given their location and propensity to recur. As part of a minimally disruptive treatment paradigm, the expanded endonasal approach has the potential to improve rates of resection, improve postoperative visual recovery, and minimize surgical morbidity. This article updates the otolaryngologic community on the basic principles and techniques regarding the incorporation of the endoscopic, endonasal approach in the management paradigm of craniopharyngioma.

Cerebrospinal fluid leaks in extended endoscopic transsphenoidal surgery: covering all the angles

Following extended endoscopic transsphenoidal approach (EETSA), cerebrospinal fluid (CSF) leak rate has been reported in the range of 5-50 %. Novel closure techniques, such as the nasoseptal flap and other multilayered repairs improved the outcomes significantly but took most of our focus. Little attention, however, was given to other aspects of the equation such as nasal support-to support the heavy weight of such repairs-and lumbar drains. These are important because they diminish the forces acting on both sides of the repair, hence covering all the angles. We reviewed data of 98 consecutive patients who underwent an EETSA between 1999 and 2014. We analyzed the rates of CSF leak throughout the years and with every modification added to our closure technique. Common pathologies encountered were invasive adenomas, meningiomas, chordomas, and craniopharyngiomas. CSF leak occurred overall in five patients (5.1 %). The nasoseptal flap decreased the rate of CSF leak but not significantly (P = 0.112), while placing a nasal trumpet to support our repair resulted in significant decrease in CSF leak rate (P = 0.0013). In the last 2 years of our series, when all modifications took place and all angles were covered, there was one leak in 35 cases (2.8 %). A protocol that covers all the angles by a good multilayered repair (regardless of its type and materials) while diminishing the forces acting on both sides of the repair leads to a minimal rate of CSF leak. No principle alone is effective individually.

Learning curve for the transsphenoidal endoscopic endonasal approach to pituitary tumors

INTRODUCTION

The transsphenoidal endoscopic approach is a relatively new procedure compared to the microscopic approach in pituitary adenoma resection. The endoscopic approach has shown to significantly decrease the rate of complications, time in the operating room and hospital, and patient post-op discomfort. However, this procedure requires the surgeon to make use of different visual and tactile clues that must be developed with experience. Therefore, it is important to understand the learning curve that the surgeon must overcome to become proficient with the endoscopic approach.

METHODS

Retrospective review of a single-surgeon consecutive series of 78 patients undergoing endoscopic pituitary tumor surgery from 2006 to 2012 at Rush University Medical Center has been used in this study. Patients were grouped according to an early (n = 9) and late group (n = 68) determined by a significant difference in outcomes. Our primary outcome measures were: duration of operation, CSF leak, hospital length of stay, visual field improvement, diabetes insipidus, panhypopituitarism, and subtotal resection.

RESULTS

There was a significant reduction in OR time and intraoperative CSF leaks between the early and late groups. There was no difference in hospital LOS or visual field improvement between the groups. With regards to complication rates, there was no difference found for DI, panhypopituitarism, lumbar drain placement, sinusitis, or subtotal resection between the two groups.

CONCLUSION

This study indicates that there may be a learning curve of approximately 9 cases before a surgical team can decrease OR times and reduce the rate of intraoperative CSF leaks for the endonasal endoscopic approach to pituitary adenoma resection.

Endonasal endoscopic reoperation for residual or recurrent craniopharyngiomas

OBJECTIVE Craniopharyngiomas can be difficult to remove completely based on their intimate relationship with surrounding visual and endocrine structures. Reoperations are not uncommon but have been associated with higher rates of complications and lower extents of resection. So radiation is often offered as an alternative to reoperation. The endonasal endoscopic transsphenoidal approach has been used in recent years for craniopharyngiomas previously removed with craniotomy. The impact of this approach on reoperations has not been widely investigated. METHODS The authors reviewed a prospectively acquired database of endonasal endoscopic resections of craniopharyngiomas over 11 years at Weill Cornell Medical College, NewYork-Presbyterian Hospital, performed by the senior authors. Reoperations were separated from first operations. Pre- and postoperative visual and endocrine function, tumor size, body mass index (BMI), quality of life (QOL), extent of resection (EOR), impact of prior radiation, and complications were compared between groups. EOR was divided into gross-total resection (GTR, 100%), near-total resection (NTR, > 95%), and subtotal resection (STR, < 95%). Univariate and multivariate analyses were performed. RESULTS Of the total 57 endonasal surgical procedures, 22 (39%) were reoperations. First-time operations and reoperations did not differ in tumor volume, radiological configuration, or patients' BMI. Hypopituitarism and diabetes insipidus (DI) were more common before reoperations (82% and 55%, respectively) compared with first operations (60% and 8.6%, respectively; p < 0.001). For the 46 patients in whom GTR was intended, rates of GTR and GTR+NTR were not significantly different between first operations (90% and 97%, respectively) and reoperations (80% and 100%, respectively). For reoperations, prior radiation and larger tumor volume had lower rates of GTR. Vision improved equally in first operations (80%) compared with reoperations (73%). New anterior pituitary deficits were more common in first operations compared with reoperations (51% vs 23%, respectively; p = 0.08), while new DI was more common in reoperations compared with first-time operations (80% vs 47%, respectively; p = 0.08). Nonendocrine complications occurred in 2 (3.6%) first-time operations and no reoperations. Tumor regrowth occurred in 6 patients (11%) over a median follow-up of 46 months and was not different between first versus reoperations, but was associated with STR (33%) compared with GTR+NTR (4%; p = 0.02) and with not receiving radiation after STR (67% vs 22%; p = 0.08). The overall BMI increased significantly from 28.7 to 34.8 kg/m² over 10 years. Six months after surgery, there was a significant improvement in QOL, which was similar between first-time operations and reoperations, and negatively correlated with STR. CONCLUSIONS Endonasal endoscopic transsphenoidal reoperation results in similar EOR, visual outcome, and improvement in QOL as first-time operations, with no significant increase in complications. EOR is more impacted by tumor volume and prior radiation. Reoperations should be offered to patients with recurrent craniopharyngiomas and may be preferable to radiation in patients in whom GTR or NTR can be achieved.

Endoscopic Endonasal Anterior Skull Base Surgery: A Systematic Review of Complications During the Past 65 Years

BACKGROUND

Endoscopic skull base surgery is becoming more popular as an approach to the anterior skull base for tumors and cerebrospinal fluid (CSF) fistulae. It offers the advantages of better cosmesis and improved quality of life after surgery. We reviewed the complication rates reported in the literature.

METHODS

A literature search was performed in the electronic database Ovid MEDLINE (1950 to August 25, 2015) with the search item "([Anterior] AND Skull base surgery) AND endoscopic."

RESULTS

We identified 82 relevant studies that included 7460 cases. An average overall complication rate of 17.1% (range 0%-68.0%) and a mortality rate of 0.4% (0%-10.0%) were demonstrated in a total of 82 studies that included 7460 cases. The average CSF leak rate for all studies was 8.9% (0%-40.0%) with meningiomas and clival lesions having the greatest CSF leak rates. The most frequent benign pathology encountered was pituitary adenomas (n = 3720, 49.8% of all cases) and the most frequent malignant tumor was esthesioneuroblastoma (n = 120, 1.6% of all cases). Studies that included only CSF fistula repairs had a lower average total complication rate (12.9%) but a greater rate of meningitis compared with studies that reported mixed pathology (2.4% vs. 1.3%). A trend towards a lower total complication rate with increasing study size was observed.

CONCLUSIONS

The endoscopic approach is an increasingly accepted technique for anterior skull base tumor surgery and is associated with acceptable complication rates. Increasing experience with this technique can decrease rates of complications.

Sensitivity and specificity of intrathecal fluorescein and white light excitation for detecting intraoperative cerebrospinal fluid leak in endoscopic skull base surgery: a prospective study

OBJECT

The intraoperative detection of CSF leaks during endonasal endoscopic skull base surgery is critical to preventing postoperative CSF leaks. Intrathecal fluorescein (ITF) has been used at varying doses to aid in the detection of intraoperative CSF leaks. However, the sensitivity and specificity of ITF at certain dosages is unknown.

METHODS

A prospective database of all endoscopic endonasal procedures was reviewed. All patients received 25 mg ITF diluted in 10 ml CSF and were pretreated with dexamethasone and Benadryl. Immediately after surgery, the operating surgeon prospectively noted if there was an intraoperative CSF leak and fluorescein was identified. The sensitivity, specificity, and positive and negative predictive power of ITF for detecting intraoperative CSF leak were calculated. Factors correlating with postoperative CSF leak were determined.

RESULTS

Of 419 patients, 35.8% of patients did not show a CSF leak. Fluorescein-tinted CSF (true positive) was noted in 59.7% of patients and 0 false positives were encountered. CSF without fluorescein staining (false negative) was noted in 4.5% of patients. The sensitivity and specificity of ITF were 92.9% and 100%, respectively. The negative and positive predictive values were 88.8% and 100%, respectively. Postoperative CSF leaks only occurred in true positives at a rate of 2.8%.

CONCLUSIONS

ITF is extremely specific and very sensitive for detecting intraoperative CSF leaks. Although false negatives can occur, these patients do not appear to be at risk for postoperative CSF leak. The use of ITF may help surgeons prevent postoperative CSF leaks by intraoperatively detecting and confirming a watertight repair.

Principles in Skull Base Reconstruction following Expanded Endoscopic Approaches

OBJECTIVES

This study aims to describe the types of anterior skull base defects following expanded endoscopic approaches (EEA) and to outline the techniques involved in the repair of these defects.

DESIGN

We retrospectively analyzed 63 cases of endoscopic skull base reconstruction (ESBR) following tumor excision, done from September 2011 to January 2015. These tumors consisted of 14 pituitary adenomas, 20 craniopharyngiomas, and 29 other miscellaneous tumors. The classification of skull base defects by Tabaee et al and the classification of cerebrospinal fluid (CSF) leaks by Esposito et al were considered during the ESBR. Recurrence of CSF leak was considered as failure of reconstruction.

RESULTS

The 63 skull base defects included in this study occurred following EEA for tumor excision. Failure of reconstruction occurred in 6 six patients. All were successfully repaired, however, three patients in this series died due to tumor-related complications.

CONCLUSION

The adherence to the general principles of reconstruction, appreciating the subtle differences in the nature of the various defects and the ability to adopt different strategies are the prerequisites for the successful closure of skull base defects.

The Expanded Endoscopic Endonasal Approach to Anterior Communicating Artery Aneurysms: A Cadaveric Morphometric Study

OBJECTIVE

The purpose of this study was to explore the endoscopic endonasal approach to the anterior communicating artery complex.

DESIGN

Anatomic, morphometric analysis of human cadaver heads.

SUBJECTS

Fifteen latex-injected adult cadaver heads.

MAIN OUTCOME MEASURES

The anatomic boundaries of the operative field and the dimensions of exposure of the anterior communicating artery (ACoA) complex were measured and clip placement feasibility was assessed.

RESULTS

Exposure of the ACoA and bilateral A1 and A2 segments was accomplished in all 15 cadaver heads. Average length of the exposed ACoA was 3 ± 1 mm, the left A1 was 5 ± 3 mm and right A1 was 5 ± 1 mm, while the A2 segment was 5 ± 2 mm bilaterally. The average distance from the alar floor to the ACoA was 95 mm, while proximal lateral limit measured between the alar floor margins was 36 mm. The distal lateral limit as defined by the distance between the lateral most exposed margins of the chiasm was 19 mm. Clip placement was accomplished for the ACoA and the A1 and A2 segments bilaterally in all specimens.

CONCLUSION

The endoscopic, endonasal transtuberculum, transplanum approach is an anatomically feasible alternative to treating select aneurysms of the ACoA complex.

Optic nerve mobilization to enhance the exposure of the pituitary stalk during craniopharyngioma resection: early experience

OBJECT Preservation of the pituitary stalk and its vasculature is a key step in good postoperative endocrinological outcome in patients with craniopharyngiomas. In this article, the authors describe the surgical technique of medial optic nerve mobilization for better inspection and preservation of the pituitary stalk. METHODS This operative technique has been applied in 3 patients. Following tumor exposure via a frontolateral approach, the pituitary stalk could be seen partially hidden under the optic nerve and the optic chiasm. The subchiasmatic and opticocarotid spaces were narrow, and tumor dissection from the pituitary stalk under direct vision was not possible. The optic canal was therefore unroofed, the falciform ligament was incised, and the lateral part of the tuberculum sellae was drilled medial to the optic nerve. The optic nerve could be mobilized medially to widen the opticocarotid triangle, which enhanced visualization of and access to the pituitary stalk. RESULTS By using the optic nerve mobilization technique, the tumor could be removed completely, and the pituitary stalk and its vasculature were preserved in all patients. In 2 patients, vision improved after surgery, while in 1 patient it remained normal, as it was before surgery. The hormonal status remained normal after surgery in 2 patients. In the patient with preoperative hormonal deficiencies, improvement occurred early after surgery and hormonal levels were normal after 3 months. No approach-related complications occurred. CONCLUSIONS This early experience shows that this technique is safe and could be used as a complementary step during microsurgery of craniopharyngiomas. It allows for tumor dissection from the pituitary stalk under direct vision. The pituitary stalk can thus be preserved without jeopardizing the optic nerve.

How I do it: shoelace watertight dural closure in extended transsphenoidal surgery

BACKGROUND

Skull base reconstruction after extended transsphenoidal surgery is essential to prevent postoperative cerebrospinal fluid leakage.

METHODS

A novel and simple technique for skull base reconstruction termed "shoelace dural closure" was devised. The dura mater was closed with a fat graft using a continuous running suture with both ends of a double-armed suture.

CONCLUSIONS

The shoelace dural closure is an effective method for achieving watertight closure of the anterior skull base without the use of lumbar drains, fascia lata grafts, or nasoseptal flaps.

Anatomic Study of Posterior Communicating Artery in Computed Tomographic Image

PURPOSE

This study aims to provide an anatomic data of posterior communicating artery (PComA) and its anatomic relationship to the adjacent structures, so as to guide surgeons in the surgery of internal carotid artery-posterior communicating artery aneurysm clipping and sellar tumors resection without injuring the PComA.

METHODS

Computer topographic angiography images of 123 individuals were reviewed, and the measurements were done on coronal, sagittal, axial, and other user-defined planes after multiplanar reconstruction. Posterior communicating artery was classified in the reconstructed three-dimensional image, measured in proper planes, and located by the structures such as anterior clinoid process (ACP), posterior clinoid process (PCP), and sagittal midline.

RESULTS

Six types of PComA were identified in this study based on its existence and origin. The initial part of PComA can be located by ACP, PCP, and sagittal midline based on some particular angles and distances.

CONCLUSIONS

Posterior communicating artery varies in different individuals, and the radiologic study of it is an optimal way to analyze the variances. The anatomic relations between PComA and basic skull structures such as the ACP and PCP are especially important for neurosurgeons.

The expanding role of the endonasal endoscopic approach in pituitary and skull base surgery: A 2014 perspective

BACKGROUND

The past two decades have been the setting for remarkable advancement in endonasal endoscopic neurosurgery. Refinements in camera definition, surgical instrumentation, navigation, and surgical technique, including the dual surgeon team, have facilitated purely endonasal endoscopic approaches to the majority of the midline skull base that were previously difficult to access through the transsphenoidal microscopic approach.

METHODS

This review article looks at many of the articles from 2011 to 2014 citing endonasal endoscopic surgery with regard to approaches and reconstructive techniques, pathologies treated and outcomes, and new technologies under consideration.

RESULTS

Refinements in approach and closure techniques have reduced the risk of cerebrospinal fluid leak and infection. This has allowed surgeons to more aggressively treat a variety of pathologies. Four main pathologies with outcomes after treatment were identified for discussion: pituitary adenomas, craniopharyngiomas, anterior skull base meningiomas, and chordomas. Within all four of these tumor types, articles have demonstrated the efficacy, and in certain cases, the advantages over more traditional microscope-based techniques, of the endonasal endoscopic technique.

CONCLUSIONS

The endonasal endoscopic approach is a necessary tool in the modern skull base surgeon's armamentarium. Its efficacy for treatment of a wide variety of skull base pathologies has been repeatedly demonstrated. In the experienced surgeon's hands, this technique may offer the advantage of greater tumor removal with reduced overall complications over traditional craniotomies for select tumor pathologies centered near the midline skull base.