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

Comparative Analysis of Endoscope Obscuration With Utilization of an Endonasal Access Guide for Endonasal Skull Base Surgery

BACKGROUND AND OBJECTIVES

In endoscopic endonasal approaches (EEAs) for skull base pathologies, endoscope view obscuration remains a persistent, time-consuming, and distracting issue for surgeons and may result in increased operative time. The endonasal access guide (EAG) has been demonstrated as a possible adjunct to minimize these events. However, to date, there have been no comparative studies performed and the potential time savings by using EAGs have yet to be quantified. This cohort study aimed to determine the operative efficiency benefits of the EAG in EEA operations.

METHODS

Analysis of EEA operative videos from an EAG cohort (n = 20) and a control cohort (n = 20) was performed, assessing 12-minute segments in the first, middle, and last third of each operation. The first segment in each cohort was selected before EAG placement, serving as an internal control. Every endoscope lens soiling instance was counted (measured as cleaning actions per minute), timed (obscuration time %), and identified as a withdrawal, irrigation, or other cleaning action. Perioperative variables including skull base repair and postoperative cerebrospinal fluid leakage were assessed.

RESULTS

Within the EAG cohort, obscuration time was reduced in the middle and last third compared with the first third (3.73% [CI: 2.39-5.07] vs 12.97% [CI: 10.24-15.70], P < .001; 4.19% [CI: 2.83-5.55] vs 12.97% [CI: 10.24-15.70], P < .001) and cleaning actions were also significantly reduced by EAG (0.69/min [CI: 0.39-0.99] vs 1.67/min [CI: 1.34-2.00], P = .001; 0.66/min [CI: 0.35-0.97] vs 1.67/min [CI: 1.34-2.00], P < .001). Between the control and EAG cohorts, there was no significant difference between obscuration time and cleaning actions in the first third (9.33% vs 12.97%, P = .086; 1.34/min vs 1.67/min, P = .151) or in the middle third (6.24% vs 3.73%, P = .140; 0.80/min vs 0.69/min, P = .335), but there was a significant difference in the last third (9.25% [CI: 6.95-11.55] vs 4.19% [CI: 2.83-5.55], P < .001; 0.95/min [CI: 0.73-1.17] vs 0.66/min [CI: 0.35-0.97], P = .018).

CONCLUSION

EAG significantly reduces lens obscurations and cleaning events, particularly during the intradural portion of operations. This technology may offer a greater time-saving impact with patients undergoing long EEA operations.

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.

90-Day Bundled Payment Simulation, Health Care Utilization, and Complications following Craniopharyngioma Resection in Adult Patients

Context Bundled payment and health care utilization models inform cost optimization and surgical outcomes. Economic analysis of payment plans for craniopharyngioma resection is unknown.

Objective This study aimed to identify impact of endocrine and nonendocrine complications (EC and NEC, respectively) on health care utilization and bundled payments following craniopharyngioma resection.

Design This study is presented as a retrospective cohort analysis (2000–2016) with 2 years of follow-up.

Setting The study included national inpatient hospitalization and outpatient visits.

Patients Patients undergoing craniopharyngioma resection were divided into the following four groups: group 1, no complications (NC); group 2, only EC; group 3, NEC; and group 4, both endocrine and nonendocrine complications (ENEC).

Interventions This study investigated transphenoidal or subfrontal approach for tumor resection.

Main Outcome Hospital readmission, health care utilization up to 24 months following discharge, and 90-day bundled payment performances are primary outcomes of this study.

Results Median index hospitalization payments were significantly lower for patients in NC cohort ($28,672) compared with those in EC ($32,847), NEC ($36,259), and ENEC ($32,596; p < 0.0001). Patients in ENEC incurred higher outpatient services and overall median payments at 6 months (NC: 38,268; EC: 49,844; NEC: 68,237; and ENEC: 81,053), 1 year (NC: 46,878; EC: 58,210; NEC: 81,043; and ENEC: 94,768), and 2 years (NC: 58,391; EC: 70,418; NEC: 98,838; and ENEC: 1,11,841; p < 0.0001). The 90-day median bundled payment was significantly different among the cohorts with the highest in ENEC ($60,728) and lowest in the NC ($33,089; p < 0.0001).

Conclusion ENEC following surgery incurred almost two times the overall median payments at 90 days, 6 months, 1 year. and 2 years compared with those without complications. Bundled payment model may not be a feasible option in this patient population. Type of complications and readmission rates should be considered to optimize payment model prediction following craniopharyngioma resection.

Endoscopic Endonasal and Supraorbital Removal of Tuberculum Sellae Meningiomas: Anatomic Guides and Operative Nuances for Keyhole Approach Selection

BACKGROUND

With growing worldwide endoscopy experience, endonasal and supraorbital removal of tuberculum sellae meningiomas (TSM) has increased.

OBJECTIVE

To describe anatomic factors for guiding approach selection and outcomes.

METHODS

Retrospective analysis of patients undergoing endonasal or supraorbital TSM resection: approach criteria, clinical outcomes, acute magnetic resonance imaging (MRI) fluid-attenuated inversion-recovery (FLAIR)/T2 changes.

RESULTS

From 2008 to 2020, 33 patients (mean age 55 ± 11 yr) were identified: 20 (61%) had endonasal and 13 (39%) supraorbital removal. Comparing endonasal and supraorbital approaches, mean tumor volume (3.7 ± 3.5 cm3 vs 7.7 ± 8.5 cm3, P = .07); percent tumor above planum (42% vs 65%, P = .02), and lateral tumor beyond supraclinoid internal carotid arteries (1.4 ± 2.0 mm vs 4.0 ± 3.2 mm, P = .006) were greater for supraorbital route. Sellar depth was greater for endonasal route tumors (12.2 ± 2.6 mm vs 9.3 ± 2.4 mm, P = .003). Endoscopy, used in 10/13(77%) supraorbital cases, was helpful in additional tumor removal in 4/10(40%). Gross total removal and mean volumetric tumor resection were 16/20(80%) and 97.5% by endonasal, and 5/13(39%) and 96% by supraorbital route. Vision improved in 12/17 (71%) endonasal, 6/8 (75%) supraorbital operations, and worsened in 1 (3%) supraorbital case. Endonasal approach with optic canal decompression increased over study period: 15/20 (75%) endonasal patients vs 1/13(8%) supraorbital (P < .001). Postoperative FLAIR/T2 MRI changes occurred in 2/12 supraorbital and 0/20 endonasal cases.

CONCLUSION

In our experience, both endonasal and supraorbital routes are safe and effective for TSM removal. Greater tumor extension below planum and medial optic canal invasion favor endonasal route, while larger size and lateral extension favor supraorbital route. Given high frequency of TSM growth into optic canals and better access for medial optic canal tumor removal, endonasal route may be preferred for most TSMs.

Evaluation of Surgical Freedom for One-and-a-Half Nostril, Mononostril, and Binostril Endoscopic Endonasal Transsphenoidal Approaches

Objective  This article determines which of the one-and-a-half nostril, mononostril, and binostril endoscopic endonasal transsphenoidal approaches provide a superior manipulation during surgery. Methods  The three approaches were orderly performed on 10 silicon-injected cadaveric heads to quantitatively assess surgical freedom and attack angle for sella. Measurements were determined with a standardized method under neuronavigation system using data of computed tomography. Results  The one-and-a-half nostril endoscopic transsphenoidal approach (OETA) offered superior exposed area than that of the mononostril approach (META), and similar to that of the binostril approach (BETA). For surgical freedom at anatomic targets, the OETA showed greater surgical flexibility at pituitary center, the right medial optic carotid recess (R-mOCR), the left mOCR, the medial intersection of the right cavernous internal carotid artery, and extension line of upper margin of the clivus (R-mICC) than those of the META, and similar to those of the BETA. For sagittal angle of attack to the R-mOCR, R-mICC, and L-mOCR, the OETA can provide better angular freedom for surgeon than that of the META, and similar to that of the BETA. The OETA had the same axial attack to the pituitary center with the BETA. The OETA and the META had limited surgical freedom at L-mICC, and both inferior to the BETA. Conclusion  The OETA has similar exposed area, surgical freedom, and attack angle for most anatomic targets to the BETA without resecting contralateral nasal septal mucosa, and obviously superior to the META.

The impact of endoscopic transsphenoidal pituitary adenoma surgery on endocrine function: a single-centre study

INTRODUCTION

The outcome for pituitary endocrine function following endoscopic transsphenoidal surgery remains unclear. This study aims to evaluate endocrine outcomes following endoscopic surgery in order to provide a benchmark to assist in the counselling of patients perioperatively.

METHODS

A prospectively held pituitary database was retrospectively analysed for all adult pituitary adenoma patients undergoing endoscopic surgery from May 2011 to May 2017. All operations were performed by a single neurosurgeon at a regional centre for pituitary surgery. Functioning and non-functioning adenomas were included. Hormonal status was assessed at most recent follow-up.

RESULTS

One hundred forty-five patients (69 M, 76 F) were included in the study with a median age of 52 years. Median follow-up was 52 months. Eighty-eight patients (61%) were not taking any hormone replacement medications, whilst 57 patients (39%) required hormone replacement therapy (HRT) preoperatively. Preoperatively, 29 patients (20%) had hypothalamo-pituitary-adrenal (HPA) axis dysfunction, 39 patients (27%) had thyroid axis dysfunction, 11 males (16%) and 7 females (9%) had gonadal axis dysfunction, and one patient had preoperative diabetes insipidus. Postoperatively, 26 patients (18%) had a new deficiency in pituitary function, whilst 6 patients (11%) were able to cease HRT. Nineteen patients (13%) had new HPA axis deterioration, 12 (8%) had new thyroid axis dysfunction, 8 males (11%) and 4 females (5%) had gonadal axis deterioration, and 6 patients (4%) had new diabetes insipidus (DI).

CONCLUSIONS

The ability to restore pituitary function following endoscopic surgery remains limited, whilst new deficits still occur. It is essential that patients are counselled accordingly as hormonal replacement therapy can have a significant impact on quality of life. Larger longer-term collaborative studies of endocrine outcome in endoscopic pituitary surgery are needed.

Application of endoscopic endonasal approach in skull base surgeries: summary of 1886 cases in a single center for 10 consecutive years

Background

Endonasal endoscopic skull base surgery has undergone rapid technological developments and is now widely performed, but its strengths and weaknesses deserve further investigation and deliberation. This study was performed to investigate the surgical indications, complications, and technical advantages and disadvantages of endonasal endoscopic skull base surgery.

Methods

The clinical data of 1886 endoscopic endonasal skull base surgeries performed in our ward at Beijing Tiantan Hospital from June 2006 to June 2016 were retrospectively analyzed.

Results

One thousand ninety-three (73.4%, 1490) pituitary adenomas, 54 (24.9%, 217) chordomas, 28 (80.0%, 35) craniopharyngiomas, and 15 (83.3%, 18) meningiomas underwent total resection. Two patients died postoperatively, both having pituitary adenomas. Other postoperative complications included olfactory disorders (n = 226, 11.9%), postoperative cerebrospinal fluid leakage (n = 78, 4.1%), hypopituitarism (n = 74, 3.9%), diabetes insipidus (n = 64, 3.4%), intracranial infection (n = 36, 1.9%), epistaxis (n = 24, 1.3%), vascular injury (n = 8, 0.4%), optic nerve injury (n = 8, 0.4%), and oculomotor movement impairment (n = 4, 0.2%). In total, 1517 (80.4%) patients were followed up for 6 to 126 months (average, 42.5 months) postoperatively. A total of 196 (13.2%) pituitary adenomas and 13 (37.1%) craniopharyngiomas recurred but no meningiomas recurred. Chordomas recurred in 97 (44.7%) patients, in whom 5-year survival rate was 65%.

Conclusion

Endoscopic surgery is an innovative surgical technique and the first choice for most midline extradural lesions such as chordomas, and an excellent choice for pituitary adenomas. It probably will be a good technique for many kinds of craniopharyngiomas and a common technique for most of skull base meningiomas, so the surgical indications of these cases should be chosen carefully to make good use of its respective advantages.

Straws Don't Suck: Are Straws Dangerous after Endoscopic Skull Base Surgery?

Objective Patients undergoing endoscopic endonasal surgery have historically been restricted from using straws postoperatively, due to the concern that this activity generates negative pressure. The objective of this study is to evaluate the pressure dynamics in the sinonasal cavity associated with the use of a straw.

Methods Intracranial pressure catheters were placed in the nasal cavity of 20 healthy individuals. Pressure measurements were then recorded while participants drank liquids of different viscosities from a cup and from a straw. Measurements were recorded with and without subjects occluding their nose to simulate postoperative nasal obstruction.

Results The average pressure in the nasal cavity while drinking water from a cup was −0.86 cmH2O, from a straw was −1.09 cmH2O, and while occluding the nose and using a straw was −0.81 cmH2O. The average pressure in the nasal cavity while drinking a milkshake from a cup was −0.98 cmH2O, from a straw was −1.88 cmH2O, and while occluding the nose and using a straw was −1.37 cmH2O. There was no statistically significant difference in pressure measurements when comparing either task or consistency (p > 0.05).

Conclusion Straw use is not associated with the generation of significant negative pressure in the nasal cavity. The pressure generated when drinking from a straw is not significantly different from that of drinking from a cup. This data suggest that straw use may be safe for patients following endoscopic skull base surgery, but further investigation is warranted.

Pituitary Adenomas: What Are the Key Features? What Are the Current Treatments? Where Is the Future Taking Us?

Pituitary tumors are a heterogeneous group of lesions (usually benign) and proper understanding of the anatomy, physiology, and pathology of the hypothalamic/pituitary region is essential to make an accurate diagnosis and define the essential treatment options (i.e., surgery, medical therapies, and radiotherapy, alone or in combination). Surgery is the primary treatment for acromegaly, Cushing disease, thyroid-stimulating hormone-secreting adenomas, resistant prolactinomas, and nonfunctioning pituitary adenomas causing mass effect. Medical and radiation therapy are reserved in cases in which surgery is not possible or does not provide a complete cure. In the last decades, tremendous innovations (i.e., targeted drugs and refined surgical tools and techniques) have expanded the treatment strategies for pituitary adenomas. We herein report the current indications for and depiction of the surgical techniques in pituitary surgery, review current medical treatments, and provide a glimpse of future possibilities.

Use of Mixed Reality Visualization in Endoscopic Endonasal Skull Base Surgery

BACKGROUND

Neuronavigation systems assist with spatial orientation during endoscopic transnasal skull base surgery, but they require a correlation of 3-dimensional (3D) views with 2-dimensional (2D) radiology studies.

OBJECTIVE

To outline an initial experience with a novel technology platform that provides intraoperative navigation using 3D reconstructions of patient anatomy for endoscopic surgery.

METHODS

A retrospective study of endoscopic anterior skull base and complex paranasal procedures was performed. Data from preoperative computed tomography and magnetic resonance imaging scans were fused to create 3D digital models of patient anatomy. Using the technology developed by Surgical Theater (Mayfield Village, Ohio), these reconstructions were designed to highlight particular anatomic regions of interest. The models were studied to guide the surgical approach and anticipate critical structures.

The reconstructions were linked with the navigational technology created by Brainlab (Munich, Germany) during endoscopic surgery. A dynamic image of the reconstruction was displayed alongside a matching endoscopic camera view. These 2 views could be overlaid to provide an immersive, mixed reality image of the patient's anatomy.

RESULTS

A total of 134 cases were performed. The pathologies included tumors of the anterior skull base or sinonasal cavity, inflammatory sinus disease, and cerebrospinal fluid leaks. Specific anatomic structures, such as the internal carotid arteries and optic nerves, were chosen for enhancement. Surgeons felt that the technology helped to guide the extent of bony dissection and to identify critical structures.

CONCLUSION

We describe the first clinical series of complex skull base pathologies treated using a novel mixed reality platform.

A Comparative Study Between Traditional Microscopic Surgeries and Endoscopic Endonasal Surgery for Skull Base Chordomas

BACKGROUND

Skull base chordomas (SBCs) are rare clinically aggressive neoplasms, developing local recurrences after surgical resection. Although SBCs have traditionally been resected by craniotomy or microscopic transsphenoidal surgery (TSS), the recent development of the endoscopic endonasal approach (EEA) has revolutionized treatment strategies through minimally invasive techniques. This study aimed to evaluate clinical outcomes after traditional microsurgeries or EEAs for SBCs.

METHODS

The present retrospective study investigated 66 patients with primary SBCs who underwent surgery between 1977 and 2019. Resection was performed via EEA in 17 cases, craniotomy in 23, transoral approach in 8, TSS in 12, staged surgery in 4, and others in 2. The median follow-up period for progression-free survival (PFS) was 19.5 months.

RESULTS

There were no significant differences in preoperative tumor volume or resection rate among these approaches. The incidence of postoperative cranial nerve palsy was significantly lower in EEA than that in craniotomy (P < 0.05). Although total resection was observed in 4 cases of EEA expanding into the superior and inferior part of the clivus, no cases of transoral approach or TSS achieved total resection for both parts. No significant difference in PFS was found among these approaches. Multivariate analysis showed that being female and the absence of radiotherapy were significantly associated with shorter PFS (P < 0.05 and P < 0.001, respectively). The resection rate was not associated with PFS.

CONCLUSIONS

EEA is a less invasive surgical approach for SBCs. The development of surgical instruments and postoperative radiotherapy will further improve patients' outcomes.

Outcomes following endoscopic endonasal resection of sellar and supresellar lesions in pediatric patients

PURPOSE

The endoscopic endonasal approach (EEA) is a credible surgical alternative for the resection of sellar and suprasellar lesions such as pituitary adenomas, craniopharyngiomas, and Rathke cleft cysts. However, its application to pediatric patients poses several unique challenges that have not yet been well evaluated. The authors evaluate the safety, efficacy, and outcomes associated with the use of the EEA for treatment of these pathologic entities in pediatric patients.

METHODS

Retrospective review of 30 patients between the ages of two and 24 who underwent endoscopic endonasal resection of sellar or suprasellar lesions between January 2010 and December 2015. Endocrinological and ophthalmological outcomes, as well as extent of resection and complications were all evaluated.

RESULTS

Gross total resection was achieved in eight of the nine pituitary adenomas, nine of the 12 craniopharyngiomas, and six of the nine Rathke cleft cysts. Of the 30 patients, 22 remained disease free at last follow-up. A total of six patients developed hypopituitarism and five developed diabetes insipidus. Eleven patients experienced improved vision, sixteen experienced no change, and one patient experienced visual worsening. Postoperative cerebrospinal fluid leak was seen in a single case and later resolved, vasospasm/stroke was experienced by 10% of patients, and new obesity was recorded in 10% of patients. There were no perioperative deaths.

CONCLUSIONS

Endoscopic endonasal resection is a safe and effective surgical alternative for the management of sellar and suprasellar pathologies in pediatric populations with excellent outcomes, minimal complications, and a low risk of morbidity.

Vestibular Neurectomy for Intractable Vertigo: Case Series and Evaluation of Role of Endoscopic Assistance in Retrolabyrinthine Craniotomy

Objective  This study evaluates the utility of endoscopy for retrolabyrinthine vestibular nerve section (RLVNS). Design/Setting  This is a retrospective review for RLVNSs by the senior author. The endoscope's utility was assessed and assigned a grade based on operative findings. Participants/Main Outcome Measures  Fifteen patients (eight males and seven females; 53 and 47%, respectively) were identified with mean age 56.7 years. Indications included Ménière's disease (MD) in 12 of 15 patients (80%), uncompensated vestibular neuritis in 2 patients (13%), and other vestibular neuropathy in 1 patient (7%). Vertigo resolved in 14 of 15 patients (93%). Complications included decreased hearing in two patients (13%) and deep venous thrombosis in one patient (7%). There were no facial nerve complications or mortalities. Results  Sectioning vestibular division of the vestibular-cochlear nerve was achieved without perceived benefit of endoscopy in the 80% of cases (grade 0, n  = 12). Endoscopy was helpful in patients with a small mastoid (grade 1, n  = 2, 13.3%), and deemed necessary where the flocculus of the cerebellum was adherent to the eighth nerve arachnoid at the porus acusticus (grade 2, n  = 1, 6.7%). Conclusion  RLVNS is a safe and efficacious procedure for the treatment of vertigo; the surgical endoscope may be a useful adjunct in selected cases. Patients with MD may expect the greatest benefit from surgery.

Bone Morphogenetic Protein in the Repair of Cerebrospinal Fluid Leak after Transsphenoidal Surgery

Background

Recurrent cerebrospinal fluid (CSF) leak carries significant morbidity. We sought to demonstrate that bone morphogenetic protein (BMP) use is effective and safe for the repair of recurrent CSF leak after a transsphenoidal pituitary tumor resection (TSPTR).

Materials and Methods

We reviewed charts and radiographic data of consecutive patients who underwent BMP repair of recurrent CSF leak after TSPTR from January 2010 to June 2015 and who failed previous multilayer closure. We detailed the technique for constructing and placing a BMP-DuraGen patch for the repair. The primary variables include postoperative computed tomography/magnetic resonance imaging (CT/MRI) evidence of ectopic bone growth or inflammation, newly diagnosed systemic neoplasm within 1 year, and recurrent CSF leak. Secondary outcome is the length of stay after BMP repair. All patients were followed up radiographically and through phone interview.

Results

Four patients underwent BMP repair of recurrent CSF leak after TSPTR. The average postoperative CT/MRI interval was 22 months. Postoperative CT/MRI revealed no ectopic bone formation or inflammatory changes around the site of BMP application. There was no recurrence of CSF leak or newly diagnosed neoplasm from both chart review and phone interview.

Conclusions

We demonstrate that the use of BMP is a safe and an effective treatment in the repair of recurrent CSF leaks after TSPTR.

Outcomes following transsphenoidal surgical management of incidental pituitary adenomas: a series of 52 patients over a 17-year period

OBJECTIVE

Incidental pituitary adenomas (IPAs) are commonly discovered during cranial imaging evaluations obtained for unrelated indications. The optimal management of IPA remains controversial. The authors investigated the outcomes and safety of the surgical treatment of IPAs at their institution.

METHODS

Clinical outcome data for 1692 patients surgically treated for pituitary adenomas at the Keck Medical Center of USC/USC Pituitary Center over a 17-year period (1999-2016) were reviewed to identify all cases with surgically managed IPAs. Clinical characteristics reviewed in this retrospective analysis included patient demographics, endocrine laboratory data, visual field examinations, and MRI results. Intraoperative data reviewed included requirement for CSF leak repair, surgical complications, and estimated extent of resection. Postoperative data collected included pathology results, length of stay, postoperative complications, endocrine outcomes, readmission rates, and long-term outcomes, including extent of resection noted on postoperative imaging studies and tumor progression and/or recurrence.

RESULTS

Fifty-two patients (3.1% of all cases) underwent transsphenoidal surgery for IPA. The median age at surgery was 61 years (range 31-86 years). The most common reasons for neuroimaging included trauma (19%), stroke/transient ischemic attack (15%), and sinonasal disease (15%). Visual field deficits were present in 15% of bedside examinations, and among the 22 patients sent for formal testing, 54.5% were noted to have deficits. Preoperative endocrine function was normal in 69% of patients, which includes 3 patients (5.8%) having isolated hyperprolactinemia consistent with a stalk effect without other hormonal dysfunction. The average maximal tumor diameter was 20.9 mm (8-50 mm; data available in 35 patients). The most common primary indication for surgery was compression of the chiasm or vision loss (52%); other major considerations included tumor growth, a young patient age, and identified endocrine abnormalities. Intraoperative CSF leak repair was performed in 56% of patients, and 1 patient (2%) developed postoperative CSF rhinorrhea treated with lumbar drainage. The median hospital stay was 2 days. There were no deaths or major complications. Three patients (5.8%) developed transient diabetes insipidus. Over a mean follow-up of 61 months, 4 patients (50.0%) reported improved headaches and 6 (54.5%) reported improvement in their visual deficits. Four patients (25%) had improved endocrine function, including one with resumption of menstruation and another with remission of acromegaly. One patient (2.4%) reported new postoperative headache, and none experienced worsened vision. Four patients (10.5%) developed new single-axis hypopituitarism and 1 (2.6%) developed new panhypopituitarism. The overall recurrence/progression rate on neuroimaging was 9.6% at a mean of 80 months.

CONCLUSIONS

Transsphenoidal resection of IPAs, when appropriate, can be performed safely at experienced treatment centers. Incidental pituitary adenomas should be evaluated and treated as indicated, especially in younger patients at risk for endocrine or visual dysfunction.

The Chance of Permanent Cure for Micro- and Macroprolactinomas, Medication or Surgery? A Systematic Review and Meta-Analysis

Background: This meta-analysis aims to evaluate the long-term efficacy of medication treatment vs. surgery treatment in patients with prolactinomas. Methods: An electronic literature search was performed using MEDLINE, EMBASE and Web of Science databases for studies dated before July in 2018. Patients with prolactinomas received primary dopamine agonists (DAs) treatment or primary surgical interventions were included in this study. A systematic review and meta-analysis were performed in pertinent studies meeting eligible criteria. The clinical outcome was measured by the long-term remission rate of prolactin (PRL) in each cohort. The pooled data was analyzed according to a random effect model. Results: Thirteen publications with total 809 patients were included in the final meta-analysis. In the overall patients with prolactinomas, long-term remission rate was achieved in 88% patients treated with surgeries and in 52% patients treated with DAs (P = 0.001). The long-term remission rates in surgery cohort were also significantly higher than medication cohort in both microprolactinomas and macroprolactinomas (91 vs. 60%, P = 0.002; 77 vs. 43%, P = 0.003). Conclusions: Patients with prolactinomas, especially microprolactinomas, can consider transsphenoidal surgery as an alternative first-line treatment strategy. After receiving primary surgical intervention, administration of DAs should be considered based on the postoperative PRL level to achieve the best long-term remission rate.

Endoscopic Approach to Clival Chordomas: The Northwestern Experience

INTRODUCTION

Chordomas are rare primary bone tumors with a low-grade histology but an aggressive clinical behavior characterized by local invasion and recurrence. When occurring in the skull base, their treatment is limited by proximity to critical neurovascular structures. Open surgical approaches can carry high morbidity, making the development of alternative approaches desirable. We describe our experience with endoscopic endonasal approaches to clival chordomas over 13 years.

METHODS

We performed a retrospective chart review of patients diagnosed with clival chordomas and treated with an endoscopic endonasal approach between 2003 and 2015 at Northwestern Memorial Hospital. We reviewed presenting symptoms, tumor location and size, extent of resection, complications, recurrence, adjuvant treatment, retreatment, and follow-up duration.

RESULTS

A total of 23 charts were reviewed, with 17 included in our final review. Mean age was approximately 48 years. The most common presenting symptom was diplopia present in 70.6% of patients. Mean tumor volume was 20.2 cm³. Gross total resection was achieved in 52.9% of patients. With a mean follow-up period of 63.4 months, 5 patients had a recurrence. The most common complication was cerebrospinal fluid (CSF) leak, which was noted in 6 patients. Tumor volume was significantly higher in patients with CSF leak. No correlation between intradural extension and postoperative CSF leak was noted.

CONCLUSIONS

Clival chordoma are challenging entities to treat. The best outcomes are achieved with gross total resection followed by adjuvant radiotherapy treatment. We show that the endonasal endoscopic corridor is a viable alternative approach to these lesions.

Extent of Endoscopic Resection for Anterior Skull Base Tumors: An MRI-Based Volumetric Analysis

Objective  To determine the volume of ventral skull base tumor removed following endoscopic endonasal (EEA) resection using MRI-based volumetric analysis and to evaluate the inter-rater reliability of such analysis. Design  Retrospective case series. Setting  Academic tertiary care hospital. Participants  EEA patients November 2012 to August 2015. Main Outcome Measures  Volumetric analysis of pre- and immediately postoperative MR imaging was performed independently by two investigators. The percentage of total tumor resected was evaluated according to resection goal and tumor type. Results  A total of 39 patients underwent resection. Intraclass correlation coefficients between the raters were 0.9988 for preoperative and 0.9819 for postoperative images. Tumors (and average percentage removed) included 17 nonsecreting pituitary adenomas (95.3%), 8 secreting pituitary adenomas (86.2%), 4 meningiomas (81.6%), 3 olfactory neuroblastomas (100%), 2 craniopharyngiomas (100%), 1 large B-cell lymphoma (90.5%), 1 germ cell neoplasm (48.3), 1 benign fibrous connective tissue mass (93.4%), 1 epidermoid cyst (68.4%), and 1 chordoma (100%). For tumors treated with intent for gross total resection, 96.9 ± 4.8% was removed. Conclusion  EEAs achieved tumor resection rates of ∼97% when total resection was attempted. The radiographic finding of residual tumor is of uncertain clinical significance. The volumetric analysis employed in this study demonstrated high inter-rater reliability and could facilitate further study.

Endoscopic Endonasal Transclival Approach versus Dual Transorbital Port Technique for Clip Application to the Posterior Circulation: A Cadaveric Anatomical and Cerebral Circulation Simulation Study

Purpose  Simulation training offers a useful opportunity to appreciate vascular anatomy and develop the technical expertise required to clip intracranial aneurysms of the posterior circulation. Materials and Methods  In cadavers, a comparison was made between the endoscopic transclival approach (ETA) alone and a combined multiportal approach using the ETA and a transorbital precaruncular approach (TOPA) to evaluate degrees of freedom, angles of visualization, and ergonomics of aneurysm clip application to the posterior circulation depending on basilar apex position relative to the posterior clinoids. Results  ETA alone provided improved access to the posterior circulation when the basilar apex was high riding compared with the posterior clinoids. ETA + TOPA provided a significantly improved functional working area for instruments and visualization of the posterior circulation for a midlevel basilar apex. A single-shaft clip applier provided improved visualization and space for instruments. Proximal and distal vascular control and feasibility of aneurysmal clipping were demonstrated. Conclusions  TOPA is a medial orbital approach to the central skull base; a transorbital neuroendoscopic surgery approach. This anatomical simulation provides surgical teams an alternative to the ETA approach alone to address posterior circulation aneurysms, and a means to preoperatively prepare for intraoperative anatomical and surgical instrumentation challenges.

Morphometric Analysis of the Middle Clinoid Process Using Maxillofacial Computed Tomography Scans

BACKGROUND

The interest in detailed anatomy of the sella and parasellar regions has resurged recently due to the wide clinical applications of the expanded endoscopic approaches to the skull base. The middle clinoid process (MCP) is a bony structure that can affect wide endoscopic exposure of the sella and parasellar region.

OBJECTIVE

To study and analyze the anatomic variations of the MCP in the general population using computed tomography scans.

METHODS

A total of 150 maxillofacial computed tomography scans were reviewed to characterize the MCP. Only adult patients without intracranial or nasal pathology were included. Measurements were made in the axial and sagittal planes to determine the maximum diameter, length, angulation, and location of the MCP.

RESULTS

The prevalence of the MCP was 30.7% in male and 42.7% in female patients. Of the MCPs, 41.8% were ring forming, whereas 76.4% were pneumatized. Quantitatively, the average axial base diameter was 4.6 ± 1.4 mm, the average sagittal base diameter was 5.0 ± 1.8 mm, the average length was 4.7 ± 1.7 mm, the average midline distance was 5.9 ± 2.3 mm, the average distance from the sellar-clival junction was 10.6 ± 3.3 mm, the average sagittal angle was 91.0 ± 21.1°, and the average axial angle was 45.2 ± 15.5°. A significant increase was found in the prevalence of MCPs in white patients compared with black patients, and a significantly greater midline distance and axial angle were found in male compared with female patients.

CONCLUSION

A clear understanding of the sellar and parasellar anatomy is crucial for successful and safe expanded endoscopic approaches. This study provides a quantitative anatomic characterization of the MCP in the U.S. population with demographic data analysis.

Contemporary Trends in the Management of Posttraumatic Cerebrospinal Fluid Leaks

The objective of this review is to provide an overview on the diagnosis and management of traumatic cerebrospinal fluid (CSF) leaks. This comprehensive review explores controversies associated with the management of CSF leaks as well as a review of the most contemporary literature. The scope of this article covers both traumatic CSF leaks of the middle and anterior cranial fossae.

Role of Endoscopic Skull Base and Keyhole Surgery for Pituitary and Parasellar Tumors Impacting Vision

Significant advances over the last 2 decades in imaging technology, instrumentation, anatomical knowledge, and reconstructive techniques have resulted in the endonasal endoscopic approach becoming an integral part of modern skull base surgery. With growing use and greater experience, surgical outcomes continue to incrementally improve across many skull base pathologies, including those tumors that impact vision and ocular motility. The importance of the learning curve and use of a multi-disciplinary approach is critical to maximizing success, minimizing complications, and enhancing quality of life in these patients. Realizing the limits of the endonasal route and reasonable use of transcranial approaches such as the supraorbital eyebrow craniotomy, it may br appropriate to consider nonsurgical therapy including various forms of radiotherapy [corrected] and medical treatment options.

Incidence and Risk Factors for Prolonged Hospitalization and Readmission after Transsphenoidal Pituitary Surgery

Objective

To evaluate the incidence and factors associated with 30-day readmission and to analyze risk factors for prolonged hospital length of stay following transsphenoidal pituitary surgery.

Study Design

Retrospective longitudinal claims analysis.

Setting

American College of Surgeons National Surgical Quality Improvement Program.

Subjects and Methods

The database of the American College of Surgeons National Surgical Quality Improvement Program was queried for patients who underwent transsphenoidal pituitary surgery ( Current Procedural Terminology code 61548 or 62165) between 2005 and 2014. Patient demographic information, indications for surgery, and incidence of hospital readmission and length of stay were reviewed. Risk factors for readmission and prolonged length of stay, defined as >75th percentile for the cohort, were identified through logistic regression modeling.

Results

A total of 1006 patients were included for analysis. Mean hospital length of stay after surgery was 4.1 ± 0.2 days. Predictors of prolonged length of stay were operative time ( P < .001, odds ratio [OR] = 1.7, 95% confidence interval [95% CI] = 1.5-2.0), bleeding disorder ( P = .049, OR = 3.1, 95% CI = 1.0-9.5), insulin-dependent diabetes ( P = .007, OR = 2.4, 95% CI = 1.3-4.4), and reoperation ( P < .001, OR = 10.3, 95% CI = 4.7-23.9). In a subset analysis of 529 patients who had surgery between 2012 and 2014, 7.2% (n = 38) required hospital readmission. History of congestive heart failure (CHF) was a predictor of hospital readmission ( P = 0.03, OR = 12.7, 95% CI = 1.1-144.0).

Conclusion

This review of a large validated surgical database demonstrates that CHF is an independent predictor of hospital readmission after transsphenoidal surgery. Although CHF is a known risk factor for postoperative complications, it poses unique challenges to patients with potential postoperative pituitary dysfunction.