A Comprehensive Analysis of Tobacco Smoking History as a Risk for Outcomes after Endoscopic Transsphenoidal Resection of Pituitary Adenoma

Objectives  This study seeks to comprehensively analyze the impact of smoking history on outcomes after endoscopic transsphenoidal hypophysectomy (TSH) for pituitary adenoma. Design  This was a retrospective study. Setting  This study was done at the tertiary care center. Participants  Three hundred and ninety-eight adult patients undergoing TSH for a pituitary adenoma. Main Outcome Measures  Clinical and tumor characteristics and operative factors were collected. Patients were categorized as never, former, or active smokers, and the pack-years of smoking history was collected. Years since cessation of smoking was obtained for former smokers. Specific outcomes included postoperative cerebrospinal fluid (CSF) leak, length of hospitalization, 30-day return to the operating room, and 30-day readmission. Smoking history details were comprehensively analyzed for association with outcomes. Results  Any history of smoking tobacco was associated with return to the operating room (odds ratio [OR] = 2.67, 95% confidence interval [CI]: 1.05-6.76, p  = 0.039), which was for persistent CSF leak in 58.3%. Among patients with postoperative CSF leak, any history of smoking was associated with need for return to the operating room to repair the CSF leak (OR = 5.25, 95% CI: 1.07-25.79, p  = 0.041). Pack-years of smoking was positively associated with a return to the operating room (OR = 1.03, 95% CI: 1.01-1.06, p  = 0.048). In all multivariable models, all negative outcomes were significantly associated with the covariate: occurrence of intraoperative CSF leak. Conclusion  This is the first study to show smoking may have a negative impact on healing of CSF leak repairs after TSH, requiring a return to the operating room. This effect appears to be dose dependent on the smoking history. Secondarily, intraoperative CSF leak as covariate in multivariable models was significantly associated with all negative outcomes.

Cortical incisions and transcortical approaches for intra-axial and intraventricular lesions: A scoping review

Background

Transcortical approaches, encompassing various surgical corridors, have been employed to treat an array of intraparenchymal or intraventricular brain pathologies, including tumors, vascular malformations, infections, intracerebral hematomas, and epileptic surgery. Designing cortical incisions relies on the lesion location and characteristics, knowledge of eloquent functional anatomy, and advanced imaging such as tractography. Despite their widespread use in neurosurgery, there is a noticeable lack of systematic studies examining their common lobe access points, associated complications, and prevalent pathologies. This scoping review assesses current evidence to guide the selection of transcortical approaches for treating a variety of intracranial pathologies.

Methods

A scoping review was conducted using the PRISMA-ScR guidelines, searching PubMed, EMBASE, Scopus, and Web of Science. Studies were included if ≥5 patients operated on using transcortical approaches, with reported data on clinical features, treatments, and outcomes. Data analysis and synthesis were performed.

Results

A total of 50 articles encompassing 2604 patients were included in the study. The most common primary pathology was brain tumors (60.6%), particularly gliomas (87.4%). The transcortical-transtemporal approach was the most frequently identified cortical approach (70.48%), and the temporal lobe was the most accessed brain lobe (55.68%). The postoperative course outcomes were reported as good (55.52%), poor (28.38%), and death (14.62%).

Conclusion

Transcortical approaches are crucial techniques for managing a wide range of intracranial lesions, with the transcortical-transtemporal approach being the most common. According to the current literature, the selective choice of cortical incision and surgical corridor based on the lesion's pathology and anatomic-functional location correlates with acceptable functional outcomes.

Interhemispheric Transcallosal Resection of Large Colloid Cyst Through Nondilated Foramen with Use of Microblade Retractor: 2-Dimensional Operative Video

Patients who present with a large colloid cyst (CC) and nondilated ventricles represent a therapeutic challenge.1-3 Although transcallosal approaches provide reliable access to the lateral ventricle and foramen of Monro, direct visualization of the vascular attachment of the CC to the roof of the third ventricle is not always possible. This can be especially true with CCs located more posteriorly and superiorly.4 Opening of the choroidal fissure can improve access and visualization to the posterior third ventricle; however, this maneuver is associated with some element of risk.5 There is a paucity of operative video in the literature illustrating the technique of gentle, microblade elevation of the fornix to improve visualization into the third ventricle and, on occasion, avoid the need to open the choroidal fissure.6 We report the case of a 28-year-old woman who presented with headaches and progressive short-term memory dysfunction (Video 1). Magnetic resonance imaging demonstrated a 17-mm CC associated with distortion and thinning of the bilateral fornices without hydrocephalus. The patient was offered interhemispheric, transcallosal resection. Intraoperatively, gentle elevation of the fornix with a microblade retractor facilitated access to the vascular attachment of the colloid cyst-obviating the need to open the choroidal fissure. The index operative video discusses the technical nuances associated with trans-callosal resection of CC with use of the microblade retractor. Special emphasis is placed on the intricate relationship of neighboring anatomic structures. The patient consented to the procedure and the publication of her image.

Neuronavigation-Specific Parameters for Selective Access of Trigeminal Rootlets in Radiofrequency Lesioning: A Cadaveric Morphometric Study

BACKGROUND AND OBJECTIVE

Radiofrequency lesioning (RFL) is a safe and effective treatment for medically refractory trigeminal neuralgia. Despite gaining mainstream neurosurgical acceptance in the 1970s, the technique has remained relatively unchanged, with the majority of series using lateral fluoroscopy over neuronavigation for cannula guidance. To date, there are no studies describing neuronavigation-specific parameters to help neurosurgeons selectively target individual trigeminal rootlets. In this cadaveric study, we sought to provide a neuronavigation-specific morphometric roadmap for selective targeting of individual trigeminal rootlets.

METHODS

Embalmed cadaveric specimens were registered to cranial neuronavigation. Frontotemporal craniotomies were then performed to facilitate direct visualization of the Gasserian ganglion. A 19-gauge cannula was retrofit to a navigation probe, permitting real-time tracking. Using preplanned trajectories, the cannula was advanced through foramen ovale (FO) to the navigated posterior clival line (nPCL). A curved electrode was inserted to the nPCL and oriented inferolaterally for V3 and superomedially for V2. For V1, the cannula was advanced 5 mm distal to the nPCL and the curved electrode was reoriented inferomedially. A surgical microscope was used to determine successful contact. Morphometric data from the neuronavigation unit were recorded.

RESULTS

Twenty RFL procedures were performed (10R, 10L). Successful contact with V3, V2, and V1 was made in 95%, 90%, and 85% of attempts, respectively. Mean distances from the entry point to FO and from FO to the clival line were 7.61 cm and 1.26 cm, respectively.

CONCLUSION

In this proof-of-concept study, we found that reliable access to V1-3 could be obtained with the neuronavigation-specific algorithm described above. Neuronavigation for RFL warrants further investigation as a potential tool to improve anatomic selectivity, operative efficiency, and ultimately patient outcomes.

The M-Point A Novel Landmark in Middle Fossa Surgery: A Cadaveric Morphometric Study

BACKGROUND

The arcuate eminence (AE) is an anatomically consistent bony protrusion located on the upper surface of the petrous bone that has been previously studied as a reference for lateral skull base approaches. There is a paucity of information in the neurosurgical literature seeking to improve the safety of the extended middle cranial fossa (MCF) approach using detailed morphometric analysis of the AE.

OBJECTIVE

To evaluate the use of the AE as an anatomical landmark to help with early identification of the internal acoustic canal (IAC) in MCF approaches by means of a cadaveric study, using a new morphometric reference termed the "M-point."

METHODS

A total of 40 dry temporal bones and 2 formalin-preserved, latex-injected cadaveric heads were used. The M-point was established as a new anatomic reference by identifying the intersection of a line perpendicular to the alignment of the petrous ridge (PR), originating from the midpoint of the AE, with the PR itself. Subsequent anatomical measurements were performed to measure the distance between M-point and IAC. Additional distances, including PR length and the anteroposterior and lateral AE surfaces, were also measured.

RESULTS

The mean distance between the M-point and the center of the IAC was 14.9 mm (SD ± 2.09), offering a safe drilling area during an MCF approach.

CONCLUSIONS

This study provides novel information on identification of a new anatomic reference point known as the M-point that that can be used to improve early surgical identification of the IAC.

Peritrigeminal Safe Entry Zone Access to Anterolateral Pons Using the Presigmoid Retrolabyrinthine Suprameatal Approach: A Cadaveric Morphometric Study

BACKGROUND AND OBJECTIVES

Access to the anterolateral pontine lesions can be achieved through the peritrigeminal and supratrigeminal safe entry zones using Kawase, retrosigmoid, or translabyrinthine approaches. However, these approaches entail shallow extensive dissection, tangential access, and compromise vestibulocochlear function. We aimed to investigate infratentorial presigmoid retrolabyrinthine approach to access pontine lesions through the peritrigeminal zone.

METHODS

We performed 10 presigmoid retrolabyrinthine suprameatal approach dissections in 5 cadaveric heads. Anatomic-radiological characteristics and variations were evaluated. Six morphometric parameters were measured and analyzed to predict surgical accessibility.

RESULTS

The pontine infratrigeminal area was accessible in all patients. The mean exposed area of the anterolateral pontine surface was 98.95 cm 2 (±38.11 cm 2 ). The mean length of the exposed trigeminal nerve was 7.9 cm (±2.9 cm). Preoperative anatomic-radiological parameters may allow to select patients with favorable anatomy that offers appropriate surgical accessibility to the anterior pontine cavernoma through a presigmoid retrolabyrinthine corridor.

CONCLUSION

Anterolateral pontine lesions can be accessed through a minimally invasive infratentorial presigmoid retrolabyrinthine approach by targeting the infratrigeminal safe entry zone. Further clinical studies should be conducted to evaluate the viability of this technique for treating these complex pathologies in real clinical settings.

A proposed classification system for presigmoid approaches: a scoping review

OBJECTIVE

The "presigmoid corridor" covers a spectrum of approaches using the petrous temporal bone either as a target in treating intracanalicular lesions or as a route to access the internal auditory canal (IAC), jugular foramen, or brainstem. Complex presigmoid approaches have been continuously developed and refined over the years, leading to great heterogeneity in their definitions and descriptions. Owing to the common use of the presigmoid corridor in lateral skull base surgery, a simple anatomy-based and self-explanatory classification is needed to delineate the operative perspective of the different variants of the presigmoid route. Herein, the authors conducted a scoping review of the literature with the aim of proposing a classification system for presigmoid approaches.

METHODS

The PubMed, EMBASE, Scopus, and Web of Science databases were searched from inception to December 9, 2022, following the PRISMA Extension for Scoping Reviews guidelines to include clinical studies reporting the use of "stand-alone" presigmoid approaches. Findings were summarized based on the anatomical corridor, trajectory, and target lesions to classify the different variants of the presigmoid approach.

RESULTS

Ninety-nine clinical studies were included for analysis, and the most common target lesions were vestibular schwannomas (60/99, 60.6%) and petroclival meningiomas (12/99, 12.1%). All approaches had a common entry pathway (i.e., mastoidectomy) but were differentiated into two main categories based on their relationship to the labyrinth: translabyrinthine or anterior corridor (80/99, 80.8%) and retrolabyrinthine or posterior corridor (20/99, 20.2%). The anterior corridor comprised 5 variations based on the extent of bone resection: 1) partial translabyrinthine (5/99, 5.1%), 2) transcrusal (2/99, 2.0%), 3) translabyrinthine proper (61/99, 61.6%), 4) transotic (5/99, 5.1%), and 5) transcochlear (17/99, 17.2%). The posterior corridor consisted of 4 variations based on the target area and trajectory in relation to the IAC: 6) retrolabyrinthine inframeatal (6/99, 6.1%), 7) retrolabyrinthine transmeatal (19/99, 19.2%), 8) retrolabyrinthine suprameatal (1/99, 1.0%), and 9) retrolabyrinthine trans-Trautman's triangle (2/99, 2.0%).

CONCLUSIONS

Presigmoid approaches are becoming increasingly complex with the expansion of minimally invasive techniques. Descriptions of these approaches using the existing nomenclature can be imprecise or confusing. Therefore, the authors propose a comprehensive classification based on the operative anatomy that unequivocally describes presigmoid approaches simply, precisely, and efficiently.

Case report of bilateral middle ear effusion requiring myringotomy and tube placement following inferior U-shaped nasopharyngeal flap elevation for endonasal odontoidectomy: investigation of causality

We describe a patient with symptomatic os odontoideum and a previous history of C1-2 wiring who underwent successful treatment with a staged endonasal odontoidectomy and C1-2 revision of instrumentation. Access to the odontoid process was gained through the endonasal corridor using an inverted U-shaped nasopharyngeal flap (IUNF). Post-operatively, the patient experienced resolution of her presenting neurologic symptoms but developed conductive hearing loss secondary to bilateral middle ear effusion, requiring bilateral myringotomy and tube placement 3 months post-operatively. We hypothesize this dysfunction may have resulted from surgical edema, packing buttressing the IUNF, or some combination thereof. In this manuscript, we review the evolution of the nasopharyngeal exposure for odontoidectomy and whether an IUNF may predispose to this complication.

External Validation of an Extreme Gradient Boosting Model for Prediction of Delayed Cerebral Ischemia after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) may significantly worsen the functional status of patients with aneurysmal subarachnoid hemorrhage (aSAH). Several authors have designed predictive models for early identification of patients at risk of post-aSAH DCI. In this study, we externally validate an extreme gradient boosting (EGB) forecasting model for post-aSAH DCI prediction.

METHODS

A 9-year institutional retrospective review of patients with aSAH was performed. Patients were included if they underwent surgical or endovascular treatment and had available follow-up data. DCI was diagnosed as new onset neurological deficits at 4-12 days after aneurysm rupture, defined as worsening GCS for ≥2 points, and new ischemic infarcts at imaging.

RESULTS

267 patients with aSAH were collected. At admission, median Hunt-Hess score was 2 (range, 1-5), median Fisher score 3 (range, 1-4), and median modified Fisher score 3 (range, 1-4). 145 patients underwent EVD placement for hydrocephalus (54.3%). The ruptured aneurysms were treated with clipping (64%), coiling (34.8%), and stent-assisted coiling (1.1%). 58 patients (21.7%) were diagnosed with clinical DCI and 82 (30.7%) with asymptomatic imaging vasospasm. The EGB classifier correctly predicted 19 cases of DCI (7.1%) and 154 cases of no-DCI (57.7%), achieving sensitivity of 32.76% and specificity of 73.68%. The calculated F1-score and accuracy were 0.288 and 64.8%, respectively.

CONCLUSION

We validated the EGB model has a potential assistant tool to predict post-aSAH DCI in clinical practice, finding moderate-high specificity but low sensitivity. Future research should investigate the underlying pathophysiology of DCI to allow the development of high-performing forecasting models.

Brain Vasculature Color-Labeling Using the Triple-Injection Method in Cadaveric Heads: A Technical Note for Improved Teaching and Research in Neurovascular Anatomy

BACKGROUND

Color-labeling injections of cadaveric heads have revolutionized education and teaching of neurovascular anatomy. Silicone-based and latex-based coloring techniques are currently used, but limitations exist because of the viscosity of solutions used.

OBJECTIVE

To describe a novel "triple-injection method" for cadaveric cranial vasculature and perform qualitative and semiquantitative evaluations of colored solution penetration into the vasculature.

METHODS

After catheter preparation, vessel cannulation, and water irrigation of embalmed cadaveric heads, food coloring, gelatin, and silicone solutions were injected in sequential order into bilateral internal carotid and vertebral arteries (red-colored) and internal jugular veins (blue-colored). In total, 6 triple-injected embalmed cadaveric heads and 4 silicone-based "control" embalmed cadaveric heads were prepared. A qualitative analysis was performed to compare the vessel coloring of 6 triple-injected heads with that of 4 "control" heads. A semiquantitative evaluation was completed to appraise sizes of the smallest color-filled vessels.

RESULTS

Naked-eye and microscope evaluations of embalmed experimental and control cadaveric heads revealed higher intensity and more distal color-labeling following the "triple-injection method" compared with the silicone-based method in both the intracranial and extracranial vasculature. Microscope assessment of 1-mm-thick coronal slices of triple-injected brains demonstrated color-filling of distal vessels with minimum diameters of 119 μm for triple-injected heads and 773 μm for silicone-based injected heads.

CONCLUSION

Our "triple-injection method" showed superior color-filling of small-sized vessels as compared with the silicone-based injection method, resulting in more distal penetration of smaller caliber vessels.

Anterior occipital condyle screw placement through the endonasal corridor: proof of concept study with cadaveric analysis

PURPOSE

Odontoidectomy for ventral compressive pathology may result in O-C1 and/or C1-2 instability. Same-stage endonasal C1-2 spinal fusion has been advocated to eliminate risks associated with separate-stage posterior approaches. While endonasal methods for C1 instrumentation and C1-2 trans-articular stabilization exist, no hypothetical construct for endonasal occipital instrumentation has been validated. We provide an anatomic description of anterior occipital condyle (AOC) screw endonasal placement as proof-of-concept for endonasal craniocervical stabilization.

METHODS

Eight adult, injected cadaveric heads were studied for placing 16 AOC screws endonasally. Thin-cut CT was used for registration. After turning a standard inferior U-shaped nasopharyngeal flap endonasally, 4 mm × 22 mm AOC screws were placed with a 0° driver using neuronavigation. Post-placement CT scans were obtained to determine: site-of-entry, measured from the endonasal projection of the medial O-C1 joint; screw angulation in sagittal and axial planes, proximity to critical structures.

RESULTS

Average site-of-entry was 6.88 mm lateral and 9.74 mm rostral to the medial O-C1 joint. Average angulation in the sagittal plane was 0.16° inferior to the palatal line. Average angulation in the axial plane was 23.97° lateral to midline. Average minimum screw distances from the jugular bulb and hypoglossal canal were 4.80 mm and 1.55 mm.

CONCLUSION

Endonasal placement of AOC screws is feasible using a 0° driver. Our measurements provide useful parameters to guide optimal placement. Given proximity of hypoglossal canal and jugular bulb, neuronavigation is recommended. Biomechanical studies will ultimately be necessary to evaluate the strength of AOC screws with plate-screw constructs utilizing endonasal C1 lateral mass or C1-2 trans-articular screws as inferior fixation points.

Surgical Closure of the Eustachian Tube Through Middle Fossa and Transmastoid Approaches: A Pilot Cadaveric Anatomy Study

BACKGROUND

Cerebrospinal fluid rhinorrhea after temporal bone surgery involves drainage from the Eustachian tube (ET) into the nasopharynx, causing significant patient morbidity. Variable anatomy of the ET accounts for failures of currently used ET obliteration techniques.

OBJECTIVE

To describe the surgical anatomy of the ET and examine possible techniques for ET closure through middle fossa (MF) and transmastoid approaches.

METHODS

We described the surgical anatomy of the ET from the MF and transmastoid approaches in 5 adult cadaveric heads, measuring morphometric and surgical anatomy parameters and establishing targets for definite ET obliteration.

RESULTS

The osseous ET measured an average of 19.53 mm (±1.56 mm), with a mean diameter of 2.24 mm (±0.29 mm). The shortest distance between the greater superficial petrosal nerve and the ET junction was 6.61 mm (±0.61 mm). Shortest distances between the ET junction and the foramen spinosum and posterior border of the foramen ovale were 1.09 mm (±0.24 mm) and 2.03 mm (±0.30 mm), respectively. Closure of the cartilaginous ET may be performed by folding it in on itself, securing it by packing, suturing, or surgical clip ligation.

CONCLUSION

Definite obliteration of the cartilaginous ET appears feasible and the most definite approach to eliminate egress of cerebrospinal fluid to the nasopharynx using the MF approach. This technique may be used as an adjunct to skull base procedures where ET closure is planned.

The functional anatomy of the foramina of Luschka revisited

Background:

The German Anatomist Hubert Von Luschka first described the foramina of Luschka (FOL) in 1855 as lateral holes in the fourth ventricle. By his discovery, he refuted previous beliefs about the lateral recess as blind ends of the fourth ventricle, proving the continuity of the ventricular system with the central canal of the spinal cord. In this paper, we question the outline variations of the patent parts of FOL and their consistency, drawing attention to the apparent query of the valvular mechanism of FOL.

Methods:

We conducted a literature review in PubMed and Google Scholar databases to review the existing literature describing the history, pertinent anatomy, and function of FOL. In addition, we reviewed the original German book written by Luschka.

Results:

While reading the available articles and original works regarding FOL, we noticed the developmental phases through which FOL was discovered, tracking the process from Aristotle till Luschka’s discovery. We also discussed controversies and opinions about FOL’s existence and function.

Conclusion:

FOL is halved into two compartments: choroidal and patent. The function of FOL resembles a oneway valve mechanism, and it depends on the patent slit-like part. Luschka had discovered over 20 anatomical structures, including several foramina, confusion in a debate may result from eponyms.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

C1 Lateral Mass Screw Placement Through Endonasal Corridor for Purpose of O-C1 Fusion: Morphometric Analysis in Cadaveric Specimens

BACKGROUND

Odontoidectomy may pose some risks for O-C1 and/or C1-C2 instability, with previous authors reporting techniques for endonasal C1-C2 fusion. However, no technique for endonasal O-C1 fusion currently exists. We sought to describe the feasibility of endonasal anterior C1 (AC1) screw placement for endonasal O-C1 fusion.

METHODS

Seven adult cadaveric heads were studied for endonasal placement of 14 C1 screws. Using thin-cut computed tomography (CT)-based "snapshot" neuronavigation assistance, 4 mm x 22 mm screws were placed in the C1 lateral mass using a 0° driver. Post-placement CT scans were obtained to determine site-of-entry measured from C1 anterior tubercle, screw angulation in axial and sagittal planes, and screw proximity to the central canal and foramen transversarium.

RESULTS

Average site-of-entry was 16.57 mm lateral, 2.23 mm rostral, and 5.53 mm deep to the anterior-most portion of the C1 ring. Average axial angulation was 19.49° lateral to midline, measured at the C1 level. Average sagittal angulation was 13.22° inferior to the palatal line, measured from the hard palate to the opisthion. Bicortical purchase was achieved in 11 screws (78.6%). Partial breach of the foramen transversarium was observed in 2 screws (14.3%), violation of the O-C1 joint space in 1 (7.1%), and violation of the central canal in 0 (0%). Average minimum screw distances from the unviolated foramen transversaria and central canal were 1.97 mm and 4.04 mm.

CONCLUSIONS

Navigation-assisted endonasal placement of AC1 screws is feasible. Additional studies should investigate the biomechanical stability of anterior C1 screw-plating systems, with anterior condylar screws as superior fixation point, compared to traditional posterior O-C1 fusion.

Complete Response of a Patient With a Mismatch Repair Deficient Aggressive Pituitary Adenoma to Immune Checkpoint Inhibitor Therapy: A Case Report

BACKGROUND AND IMPORTANCE

Aggressive pituitary adenomas (APAs) are pituitary tumors that are refractory to standard treatments and carry a poor prognosis. Current treatment guidelines are not standardized but combine surgical resection, radiation therapy, and chemotherapy. Temozolomide is the only chemotherapeutic agent with documented effectiveness and is recommended for APA in European Society of Endocrinology clinical guidelines.

CLINICAL PRESENTATION

A 57-year-old man presented with visual deterioration and bitemporal hemianopsia. MRI of the brain demonstrated a sellar mass suspected to be pituitary macroadenoma with displacement of the stalk and optic nerve impingement. The patient underwent stereotactic endoscopic transsphenoidal resection of the mass. Postoperative MRI demonstrated gross total resection. Pathology revealed a sparsely granulated corticotroph adenoma with malignant transformation. Immunohistochemistry showed loss of expression of MLH1 and PMS2 in the tumor cells. Proton therapy was recommended given an elevated Ki67 index and p53 positivity. Before radiotherapy, there was no radiographic evidence of residual tumor. Temozolomide therapy was initiated after surveillance MRI showed recurrence at 16 months postoperatively. However, MRI demonstrated marked progression after 3 cycles. Next-generation sequencing using the MSK-IMPACT platform identified somatic mutations in MLH1 Y548lfs*9 and TP53 R337C . Immunotherapy with ipilimumab/nivolumab was initiated, and MRI demonstrated no residual tumor burden 34 months postoperatively.

CONCLUSION

APA is a tumor with frequent recurrence and a short median expected length of survival. Here, we demonstrate the utility of immunotherapy in a single case report of APA, with complete resolution of recurrent APA and improved survival compared with life expectancy.

Roadmap to Ventral Craniocervical Junction Through the Endonasal Corridor: Anatomic Evaluation of Inverted U-Shaped Nasopharyngeal Flap Exposure in a Cadaveric Study

BACKGROUND

There is a paucity of data in the literature describing quantitative exposure of the ventral craniocervical junction through the endonasal corridor in a safe manner mindful of locoregional anatomy.

OBJECTIVE

To quantify ventromedial exposure of O-C1 and C1-2 articular structures after turning an inverted U-shaped nasopharyngeal flap (IUNF) and to obtain measurements assessing the distance of flap margins to adjacent neurovascular structures.

METHODS

In 8 cadaveric specimens, an IUNF was fashioned using a superior incision below the level of the pharyngeal tubercule of the clivus and lateral incisions in the approximate region of Rosenmuller fossae bilaterally. Measurements with calipers and/or neuronavigation software included flap dimensions, exposure of O-C1 and C1-2 articular structures, inferior reach of IUNF, and proximity of the internal carotid artery (ICA) and hypoglossal nerve to IUNF margins.

RESULTS

The IUNF facilitated exposure of an average of 9 mm of the medial surfaces of the right/left O-C1 joints without transgression of the carotid arteries or hypoglossal nerves. The C1-2 articulation could not be routinely accessed. The margins of the IUNF were not in close (<5 mm) proximity to the ICA in any of the 8 specimens. In 6 of 8 specimens, the dimensions of the IUNF were in close (<5 mm) horizontal or vertical proximity to the hypoglossal foramina.

CONCLUSION

The IUNF provided safe and reliable access to the medial O-C1 articulation. Given the close proximity of the exocranial hypoglossal foramen, neuronavigation assistance and neuromonitoring with attention to the superolateral IUNF margin are recommended.

Primary Dural Repair via an Endoscopic Endonasal Corridor: Preliminary Development of a 3D-Printed Model for Training

Objectives Endonasal suturing is an investigational method for dural repair that has been reported to decrease the incidence of cerebrospinal fluid fistula. This method requires handling of single-shaft instrumentation in the narrow endonasal corridor. In this study, we designed a low-cost, surgical model using three-dimensional (3D) printing technology to simulate dural repair through the endonasal corridor and subsequently assess the utility of the model for surgical training.

Methods Using an Ultimaker 2+ printer, a 3D-printed replica of the cranial base and nasal cavity was fitted with tissue allograft to recapitulate the dural layer. Residents, fellows, and attending surgeons were asked to place two sutures using a 0-degree endoscope and single-shaft needle driver. Task completion time was recorded. Participants were asked to fill out a Likert scale questionnaire after the experiment.

Results Twenty-six participants were separated into groups based on their prior endoscope experience: novice, intermediate, and expert. Twenty-one (95.5%) residents and fellows rated the model as “excellent” or “good” in enhancing their technical skills with endoscopic instrumentation. Three of four (75%) of attendings felt that the model was “excellent” or “good” in usefulness for training in dural suturing. Novice participants required an average of 11 minutes for task completion, as compared with 8.7 minutes for intermediates and 5.7 minutes for experts.

Conclusion The proposed model appears to be highly effective in enhancing the endoscopic skills and recapitulating the task of dural repair. Such a low-cost model may be especially important in enhancing endoscopic facility in countries/regions with limited access to cadaveric specimens.

2D versus 3D Endoscopy: Head-to-Head Comparison in a Simulated Model of Endoscopic Endonasal Dural Suturing

Objective Endonasal dural suturing (EDS) has been reported to decrease the incidence of cerebrospinal fluid fistula. This technique requires handling of single-shaft instrumentation in the narrow endonasal corridor. It has been proposed that three-dimensional (3D) endoscopes were associated with improved depth perception. In this study, we sought to perform a comparison of two-dimensional (2D) versus 3D endoscopy by assessing surgical proficiency in a simulated model of EDS.

Materials and Methods Twenty-six participants subdivided into groups based on previous endoscopic experience were asked to pass barbed sutures through preset targets with either 2D (Storz Hopkins II) or 3D (Storz TIPCAM) endoscopes on 3D-printed simulation model. Surgical precision and procedural time were measured. All participants completed a Likert scale questionnaire.

Results Novice, intermediate, and expert groups took 11.0, 8.7, and 5.7 minutes with 2D endoscopy and 10.9, 9.0, and 7.6 minutes with 3D endoscopy, respectively. The average deviation for novice, intermediate, and expert groups (mm) was 5.5, 4.4, and 4.3 with 2D and 6.6, 4.6, and 3.0 with 3D, respectively. No significant difference in procedural time or accuracy was found in 2D versus 3D endoscopy. 2D endoscopic visualization was preferred by the majority of expert/intermediate participants, while 3D endoscopic visualization by the novice group.

Conclusion In this pilot study, there was no statistical difference in procedural time or accuracy when utilizing 2D versus 3D endoscopes. While it is possible that widespread familiarity with 2D endoscopic equipment has biased this study, preliminary analysis suggests that 3D endoscopy offers no definitive advantage over 2D endoscopy in this simulated model of EDS.

An algorithm to improve lateralization accuracy of inferior petrosal sinus sampling: procedural nuances for complex patterns of venous drainage. Patient series

BACKGROUND

Inferior petrosal sinus sampling (IPSS) is a useful technique in the diagnosis of Cushing’s disease (CD) when the imaging finding is negative or equivocal. Different authors have reported considerable variability in the ability to determine tumor laterality with IPSS. Here the authors present a retrospective case series of 7 patients who underwent IPSS using a systematic algorithm to improve lateralization accuracy by identifying optimal sampling sites on the basis of individual cavernous sinus drainage patterns in each patient.

OBSERVATIONS

Of the 7 patients identified, 6 were determined to have CD and subsequently underwent surgery. IPSS was accurate in all patients from whom laterality was predicted. Arterial and venous angiography were used to define cavernous sinus drainage patterns and determine optimal sampling sites. All patients who underwent surgery achieved hormonal cure.

LESSONS

All IPSS predictions of lateralization were correct when available, and all patients who underwent surgery achieved hormonal cure. Advances in angiographic techniques for identification of the site of primary drainage from the cavernous sinus and subsequent optimization of microcatheter placement may improve the ability to predict tumor laterality.

Case Report of Transgender Patient with Gonadotropic Dysfunction Secondary to Craniopharyngioma: Toward Improving Understanding of Biopsychosocial Dynamics of Gender Identity in Neurosurgical Care

BACKGROUND

There is a paucity of information in the literature linking possible neuroendocrinologic repercussions of anterior pituitary insufficiency from tumor-associated mass effect with gender identity in transindividuals. The authors present the case of a 26-year-old transgender woman who was found to have a sellar/suprasellar neoplasm after reporting loss of vision in a bitemporal distribution.

CASE DESCRIPTION

Magnetic resonance imaging demonstrated a 2.6-cm complex cystic and solid sellar/suprasellar mass, suggestive of craniopharyngioma, intimately associated with the pituitary stalk. Importantly, this radiographic diagnosis was made 2 years following the initiation of gender-affirming hormone therapy (HT). Laboratory testing following radiographic diagnosis demonstrated evidence of diffuse anterior pituitary insufficiency with decreased morning cortisol, free thyroxine, insulin-like growth factor-1, and testosterone. Following optimization with the endocrinology team, the patient was taken to the operating room for expanded endonasal resection of tumor with lumbar drain insertion and nasoseptal flap coverage. Gross total resection was achieved with marked improvement in vision noted following surgery. The patient continued her HT following surgery.

CONCLUSIONS

In hindsight, the neuroendocrinologic manifestations of the craniopharyngioma may have influenced distressing pubertal experiences that distanced her from her assigned male sex, as well as the desired effects of feminization HT in this patient, ultimately delaying her presentation to the neurosurgery service and diagnosis of craniopharyngioma. As the first report of the neurosurgical evaluation and treatment of a transgender patient with anterior pituitary insufficiency secondary to craniopharyngioma, this case examines the biopsychosocial interplay between the development of gender identity and the neuroendocrinologic manifestations of craniopharyngioma.

Pterional Craniotomy for Resection of Clinoidal Meningioma Associated With an Aerated Anterior Clinoid Process: 2-Dimensional Operative Video

Extradural removal of the clinoid performed prior to resection of clinoidal meningiomas has been advocated as a way to facilitate devascularization of the tumor and provide early identification and/or decompression of adjacent neurovascular structures. A small number of video publications exist in the literature that provides useful guidance to surgeons preparing for resection of clinoidal region meningiomas.1-3 However, none of these videos portray the variable anatomy associated with an aerated clinoid process. This known anatomical variant can increase the risk profile associated with resection of clinoidal meningomas-especially with regards to postoperative cerebrospinal fluid (CSF) fistula.  In this video publication, we discuss the care of a 54 yr-old male who presented with visual deterioration in the right eye. Magnetic resonance imaging (MRI) revealed findings consistent with a right clinoidal meningioma. Computed tomography demonstrated bilateral aeration of the anterior clinoid processes. The patient was taken to the operating room for right pterional craniotomy for resection of the neoplasm. Edited, intraoperative 2-dimensional-video demonstrates the variable anatomy encountered during removal of an aerated clinoid process. Relevant steps associated with subsequent tumor resection are summarized. Following resection, MRI obtained in the early postoperative period demonstrated gross total resection of the neoplasm without untoward finding. The patient noted marked improvement in his vision following surgery and did not suffer any complications relating to postoperative CSF fistula. Full patient consent for photography and/or recording of other forms of video/imaging was obtained in the preoperative period.

Decision-making algorithm for minimally invasive approaches to anterior skull base meningiomas

OBJECTIVE Anterior skull base meningiomas are benign lesions that cause neurological symptoms through mass effect on adjacent neurovascular structures. While traditional transcranial approaches have proven to be effective at removing these tumors, minimally invasive approaches that involve using an endoscope offer the possibility of reducing brain and nerve retraction, minimizing incision size, and speeding patient recovery; however, appropriate case selection and results in large series are lacking. METHODS The authors developed an algorithm for selecting a supraorbital keyhole minicraniotomy (SKM) for olfactory groove meningiomas or an expanded endoscopic endonasal approach (EEA) for tuberculum sella (TS) or planum sphenoidale (PS) meningiomas based on the presence or absence of olfaction and the anatomical extent of the tumor. Where neither approach is appropriate, a standard transcranial approach is utilized. The authors describe rates of gross-total resection (GTR), olfactory outcomes, and visual outcomes, as well as complications, for 7 subgroups of patients. Exceptions to the algorithm are also discussed. RESULTS The series of 57 patients harbored 57 anterior skull base meningiomas; the mean tumor volume was 14.7 ± 15.4 cm³ (range 2.2-66.1 cm³), and the mean follow-up duration was 42.2 ± 37.1 months (range 2-144 months). Of 19 patients with olfactory groove meningiomas, 10 had preserved olfaction and underwent SKM, and preservation of olfaction in was seen in 60%. Of 9 patients who presented without olfaction, 8 had cribriform plate invasion and underwent combined SKM and EEA (n = 3), bifrontal craniotomy (n = 3), or EEA (n = 2), and one patient without both olfaction and cribriform plate invasion underwent SKM. GTR was achieved in 94.7%. Of 38 TS/PS meningiomas, 36 of the lesions were treated according to the algorithm. Of these 36 meningiomas, 30 were treated by EEA and 6 by craniotomy. GTR was achieved in 97.2%, with no visual deterioration and one CSF leak that resolved by placement of a lumbar drain. Two patients with tumors that, based on the algorithm, were not amenable to an EEA underwent EEA nonetheless: one had GTR and the other had a residual tumor that was followed and removed via craniotomy 9 years later. CONCLUSIONS Utilizing a simple algorithm aimed at preserving olfaction and vision and based on maximizing use of minimally invasive approaches and selective use of transcranial approaches, the authors found that excellent outcomes can be achieved for anterior skull base meningiomas.

Elective neurosurgical humanitarian care in a deployed setting

OBJECTIVEActive-duty neurosurgical coverage has been provided at Bagram Air Force Base in Afghanistan since 2007. Early operative logs were reflective of a large number of surgical procedures performed to treat battlefield injuries. However, with maturation of the war effort, the number of operations for battlefield injuries has decreased with time. Consequently, procedures performed for elective neurosurgical humanitarian care (NHC) increased in number and complexity prior to closure of the Korean Hospital in 2015, which resulted in effective termination of NHC at Bagram. Monthly neurosurgical caseloads for deployed personnel have dropped precipitously since this time, renewing a debate as to whether the benefits of providing elective NHC in Afghanistan outweigh the costs of such a strategy. To date, there is a paucity of information in the literature discussing the overall context of such a determination.METHODSThe author retrospectively reviewed his personal database of all patients who underwent neurosurgical procedures at Bagram during his deployment there from April 17 to October 29, 2014. Standardized clinical parameters had been recorded in the ABNS NeuroLog system. All cases of nonelective surgical care for battlefield injuries were identified and excluded. Records of all other procedures, which represented elective NHC delivered during this period, were accessed to extract salient clinical and radiological data.RESULTSDuring the 6-month deployment, 49 patients (29 male and 20 female, age range 18 months to 63 years) were treated by the author in elective NHC. Procedures were performed for spinal degenerative disease (n = 28), cranial tumors (n = 11), pediatric conditions (n = 6), Pott's disease (n = 2), peripheral nerve impingement (n = 1), and adult hydrocephalus (n = 1). The duration of follow-up ranged from 3 to 23 weeks. Complications referable to surgery included asymptomatic, unilateral lumbar screw fracture detected 3 months postoperatively and treated with revision of hardware (n = 1); wound infection requiring cranial flap explantation and staged cranioplasty (n = 1); and unanticipated return to the operating room for resection of residual tumor in a patient with a solitary metastatic lesion involving the mesial temporal lobe/ambient cistern (n = 1). There were no instances of postoperative neurological decline.CONCLUSIONSElective NHC can be safely and effectively implemented in the deployed setting. Benefits of a military strategy that supports humanitarian care include strengthening of the bond between the US/Afghan military communities and the local civilian population as well as maintenance of skills of the neurosurgical team during the sometimes-lengthy intervals between cases in which emergent neurosurgical care is provided for treatment of battlefield injuries.

BRAF V600E mutant papillary craniopharyngiomas: a single-institutional case series

PURPOSE

To describe the clinical, radiographic and surgical outcomes in a cohort of patients with BRAF V600E mutant papillary craniopharyngiomas.

METHODS

A retrospective review was performed to identify all patients with a histological diagnosis of CP operated upon at a single institution between 2005 and 2017. All cases with adequate material were sequenced to confirm the presence of BRAF V600E mutation.

RESULTS

Sixteen patients were included in the present study. Approach was endoscopic endonasal (EEA) in 14 and transcranial (TCA) in 2. All patients were adult with an average age of 50 years (24-88). Radiographic review demonstrated that the majority (93.7%) were suprasellar and twelve (75%) had third ventricular involvement. No tumor showed evidence of calcifications and 68.7% were mixed solid-cystic. All patients had some evidence of hypopituitarism and 62.5% had hypothalamic disturbances. GTR was achieved in 11/14 (78.6%) EEA and 0/2 (0%) TCA (p < 0.05). The mean length of stay was 17.5 days in the TCA group and 7.6 days in the EEA group (p < 0.05). There were no CSF leaks. Post-operatively, eleven (68.7%) developed new DI or new hypopituitarism. Nine increased their BMI with a mean increase of 12.3%, whereas six patients lost weight with a mean decrease of 5.3%.

CONCLUSIONS

BRAF V600E mutant papillary tumors represent a clearly distinct clinical-pathological entity of craniopharyngiomas. These are generally non-calcified suprasellar tumors that occur in adults. These distinct characteristics may someday lead to upfront chemotherapy. When surgery is necessary, EEA may be preferred over TCA.

Preserve or sacrifice the stalk? Endocrinological outcomes, extent of resection, and recurrence rates following endoscopic endonasal resection of craniopharyngiomas

OBJECTIVE

Gross-total resection (GTR) of craniopharyngiomas (CPs) is potentially curative and is often the goal of surgery, but endocrinopathy generally results if the stalk is sacrificed. In some cases, GTR can be attempted while still preserving the stalk; however, stalk manipulation or devascularization may cause endocrinopathy and this strategy risks leaving behind small tumor remnants that can recur.

METHODS

A retrospective review of a prospective cohort of patients who underwent initial resection of CP using the endoscopic endonasal approach over a period of 12 years at Weill Cornell Medical College, NewYork-Presbyterian Hospital, was performed. Postresection integrity of the stalk was retrospectively assessed using operative notes, videos, and postoperative MRI. Tumors were classified based on location into type I (sellar), type II (sellar-suprasellar), and type III (purely suprasellar). Pre- and postoperative endocrine function, tumor location, body mass index, rate of GTR, radiation therapy, and complications were reviewed.

RESULTS

A total of 54 patients who had undergone endoscopic endonasal procedures for first-time resection of CP were identified. The stalk was preserved in 33 (61%) and sacrificed in 21 (39%) patients. GTR was achieved in 24 patients (73%) with stalk preservation and 21 patients (100%) with stalk sacrifice (p = 0.007). Stalk-preservation surgery achieved GTR and maintained completely normal pituitary function in only 4 (12%) of 33 patients. Permanent postoperative diabetes insipidus was present in 16 patients (49%) with stalk preservation and in 20 patients (95%) following stalk sacrifice (p = 0.002). In the stalk-preservation group, rates of progression and radiation were higher with intentional subtotal resection or near-total resection compared to GTR (67% vs 0%, p < 0.001, and 100% vs 12.5%, p < 0.001, respectively). However, for the subgroup of patients in whom GTR was achieved, stalk preservation did not lead to significantly higher rates of recurrence (12.5%) compared with those in whom it was sacrificed (5%, p = 0.61), and stalk preservation prevented anterior pituitary insufficiency in 33% and diabetes insipidus in 50%.

CONCLUSIONS

While the decision to preserve the stalk reduces the rate of postoperative endocrinopathy by roughly 50%, nevertheless significant dysfunction of the anterior and posterior pituitary often ensues. The decision to preserve the stalk does not guarantee preserved endocrine function and comes with a higher risk of progression and need for adjuvant therapy. Nevertheless, to reduce postoperative endocrinopathy attempts should be made to preserve the stalk if GTR can be achieved.

Endonasal endoscopic transsphenoidal resection of intrinsic third ventricular craniopharyngioma: surgical results

OBJECTIVE

Intrinsic third ventricular craniopharyngiomas (IVCs) have been reported by some authors to "pose the greatest surgical challenge" of all craniopharyngiomas (CPAs). A variety of open microsurgical approaches have historically been used for resection of these tumors. Despite increased utilization of the endoscopic endonasal approach (EEA) for resection of CPAs in recent years, many authors continue to recommend against use of the EEA for resection of IVCs. In this paper, the authors present the largest series to date utilizing the EEA to remove IVCs.

METHODS

The authors reviewed a prospectively acquired database of the EEA for resection of IVCs over 14 years at Weill Cornell Medical College, NewYork-Presbyterian Hospital. Preoperative MR images were examined independently by two neurosurgeons and a neuroradiologist to identify IVCs. Pre- and postoperative endocrinological, ophthalmological, radiographic, and other morbidities were determined from retrospective chart review and volumetric radiographic analysis.

RESULTS

Between January 2006 and August 2017, 10 patients (4 men, 6 women) ranging in age from 26 to 67 years old, underwent resection of an IVC utilizing the EEA. Preoperative endocrinopathy was present in 70% and visual deterioration in 60%. Gross-total resection (GTR) was achieved in 9 (90%) of 10 patients, with achievement of near-total (98%) resection in the remaining patient. Pathology was papillary in 30%. Closure incorporated a "gasket-seal" technique with nasoseptal flap coverage and either lumbar drainage (9 patients) or a ventricular drain (1 patient). Postoperatively, complete anterior and posterior pituitary insufficiency was present in 90% and 70% of patients, respectively. In 4 patients with normal vision prior to surgery, 3 had stable vision following tumor resection. One patient noted a new, incongruous, left inferior homonymous quadrantanopsia postoperatively. In the 6 patients who presented with compromised vision, 2 reported stable vision following surgery. Each of the remaining 4 patients noted significant improvement in vision after tumor resection, with complete restoration of normal vision in 1 patient. Aside from the single case (10%) of visual deterioration referenced above, there were no instances of postoperative neurological decline. Postoperative CSF leakage occurred in 1 morbidly obese patient who required reoperation for revision of closure. After a mean follow-up of 46.8 months (range 4-131 months), tumor recurrence was observed in 2 patients (20%), one of whom was treated with radiation and the other with chemotherapy. Both of these patients had previously undergone GTR of the IVC.

CONCLUSIONS

The 10 patients described in this report represent the largest number of patients with IVC treated using EEA for resection to date. EEA for resection of IVC is a safe and efficacious operative strategy that should be considered a surgical option in the treatment of this challenging subset of tumors.

Radiation therapy rather than prior surgery reduces extent of resection during endonasal endoscopic reoperation for craniopharyngioma

OBJECTIVE

Radiation therapy is often advocated for residual or recurrent craniopharyngioma following surgical resection to prevent local recurrence. However, radiation therapy is not always effective and may render tumors more difficult to remove. If this is the case, patients may benefit more from reoperation if gross total resection can be achieved. Nevertheless, there is little data on the impact of radiation on reoperations for craniopharyngioma. In this study, we sought to analyze whether a history of previous radiation therapy (RT) affected extent of resection in patients with recurrent craniopharyngiomas subsequently treated with reoperation via endoscopic endonasal approach (EEA).

METHODS

The authors reviewed a prospectively acquired database of EEA reoperations of craniopharyngiomas over 13 years at Weill Cornell, NewYork-Presbyterian Hospital. All procedures were performed by the senior author. The operations were separated into two groups based on whether the patient had surgery alone (group A) or surgery and RT (group B) prior to recurrence.

RESULTS

A total of 24 patients (16 male, 8 female) who underwent surgery for recurrent craniopharyngioma were identified. The average time to recurrence was 7.64 ± 4.34 months (range 3-16 months) for group A and 16.62 ± 12.1 months (range 6-45 months) for group B (p < 0.05). The average tumor size at recurrence was smaller in group A (1.85 ± 0.72 cm; range 0.5-3.2) than group B (2.59 ± 0.91 cm; range 1.5-4.6; p = 0.00017). Gross total resection (GTR) was achieved in 91% (10/11) of patients in group A and 54% (7/13) of patients in group B (p = 0.047). There was a near significant trend for higher average Karnofsky performance status (KPS) score at last follow-up for group A (83 ± 10.6) compared with group B (70 ± 16.3, p = 0.056).

CONCLUSIONS

While RT for residual or recurrent craniopharyngioma may delay time to recurrence, ability to achieve GTR with additional surgery is reduced. In the case of recurrent craniopharyngioma, if GTR can be achieved, consideration should be given to endonasal reoperation prior to the decision to irradiate residual or recurrent tumor.

Endoscopic endonasal resection of epidermoid cysts involving the ventral cranial base

OBJECTIVE

Epidermoid cysts (ECs) commonly extend to involve the ventral cisterns of the cranial base. When present, symptoms arise due to progressive mass effect on the brainstem and adjacent cranial nerves. Historically, a variety of open microsurgical approaches have been used for resection of ECs in this intricate region. In recent years, the endoscopic endonasal approach (EEA) has been proposed as an alternative corridor that avoids crossing the plane of the cranial nerves. To date, there is a paucity of data in the literature regarding the safety and efficacy of the EEA in the treatment of ECs of the ventral cranial base.

METHODS

The authors reviewed a prospectively acquired database of EEAs for resection of ECs over 8 years at Weill Cornell, NewYork-Presbyterian Hospital. All procedures were performed by the senior authors. Standardized clinical and radiological parameters were assessed before and after surgery. Statistical tests were used to determine the impact of previous surgery and tumor volume on extent of resection and recurrence as well as the method of closure on rate of CSF leak.

RESULTS

Between January 2009 and February 2017, 7 patients (4 males and 3 females; age range 16-70 years) underwent a total of 8 surgeries for EC resection utilizing the EEA. Transplanum and transclival extensions were performed in 3 and 5 patients, respectively. Methods of closure incorporated a gasket seal in 6 of 8 procedures and a nasoseptal flap in 7 of 8 procedures. Gross-total resection (GTR) was achieved in 43% of patients, and near-total resection (> 95%) was obtained in another 43%. Complications included diabetes insipidus (n = 2), postoperative CSF leak (n = 2), transient third cranial nerve palsy (n = 1), and epistaxis (n = 1). With a mean follow-up of 43.5 months, recurrence has been observed in 2 of 7 patients. In 1 case, reoperation for recurrence was required 71 months following the initial surgery. Use of the gasket-seal technique with nasoseptal flap coverage significantly correlated with the absence of postoperative CSF leakage (p = 0.018). GTR was achieved in 25% of the patients who had prior surgeries and in 50% of patients without previous resections. The mean volume of cysts in which GTR was achieved (4.3 ± 1.8 cm3) was smaller than that in which subtotal or near-total resection was achieved (12.2 ± 11 cm3, p = 0.134).

CONCLUSIONS

The EEA for resection of ECs of the ventral cranial base is a safe and effective operative strategy that avoids crossing the plane of the cranial nerves. In the authors' experience, gasket-seal closure with nasoseptal flap coverage has been associated with a decreased risk of postoperative CSF leakage.

Cervical corpectomy for resection of ventral intramedullary capillary hemangioma with circumferential involvement of the anterior spinal artery: case report

There is limited evidence to suggest that anterior approaches for the resection of ventral intramedullary lesions of the cervical spinal cord may result in superior neurological outcomes compared with those following more traditional posterior approaches. To the authors' knowledge, no report of an anterior approach to resect a ventral intramedullary capillary hemangioma exists in the literature. In the following paper, the case of a 75-year-old male who presented with progressive neck and left shoulder pain, weakness of the left hand, myelopathy, and gait imbalance is reported. Postcontrast T1-weighted MRI demonstrated a homogeneously enhancing intramedullary lesion with associated severe impingement of the cervical spinal cord at C-4. Following a C-4 corpectomy, intradural exposure revealed a vascular lesion that circumferentially enveloped the anterior spinal artery. Gross-total resection of the lesion was performed, followed by reconstruction of the corpectomy defect, without neurological deterioration. Pathology was consistent with capillary hemangioma. In this instance, the anterior approach helped to avoid unnecessary neural manipulation and allowed for early identification of normal proximal and distal segments of the anterior spinal artery, which facilitated safe dissection and gross-total removal.

Neurovascular Compression at the Root Entry Zone Correlates with Trigeminal Neuralgia and Early Microvascular Decompression Outcome

BACKGROUND

Trigeminal neurovascular contact (NVC) is hypothesized to be the etiology of classical trigeminal neuralgia (TGN). We aimed to seek a correlation between types of NVCs and the presence of TGN as well as early surgical outcome in patients with TGN treated with trigeminal microvascular decompression (MVD).

METHODS

We blindly analyzed preoperative high-resolution magnetic resonance images with respect to the degree (none, "touch," or compression) and location of bilateral NVC in 57 retrospectively identified Burchiel Type 1 TGN patients treated by MVD. Location of NVC was noted as either at the root entry zone or distal to it. Using a logistic regression model, we assessed the degree and location of trigeminal NVC for correlation with the symptomatic side. Furthermore, the NVC characteristics on the symptomatic side were correlated with early postoperative pain relief.

RESULTS

Although the degree and location of NVC were not statistically correlative independently, a combined interaction analysis of both statistically correlated with the symptomatic side and with early postoperative pain relief.

CONCLUSIONS

We conclude that in TGN patients treated with MVD, magnetic resonance imaging identified neurovascular compression at the root entry zone (correlates with the affected side and early postoperative pain relief.

Stratification of risk to the surgical team in removal of small arms ammunition implanted in the craniofacial region: case report

In cases of penetrating injury with implantation of small arms ammunition, it can often be difficult to tell the difference between simple ballistics and ballistics associated with unexploded ordnances (UXOs). In the operative environment, where highly flammable substances are often close to the surgical site, detonation of UXOs could have catastrophic consequences for both the patient and surgical team. There is a paucity of information in the literature regarding how to evaluate whether an implanted munition contains explosive material. This report describes a patient who presented during Operation Enduring Freedom with an implanted munition suspicious for a UXO and the subsequent workup organized by Explosive Ordnance Disposal (EOD) Company prior to surgical removal. Clinical risk factors for UXOs include assassination attempts and/or wartime settings. Specific radiological features suggestive of a UXO include projectile size greater than 7.62-mm caliber, alterations in density of the tip, as well as radiological evidence of a hollowed-out core. If an implanted UXO is suspected, risks to the surgical and anesthesia teams can be minimized by notifying the nearest military installation with EOD capabilities and following clinical practice guidelines set forth by the Joint Theater Trauma System.

Retrosigmoid craniotomy for resection of acoustic neuroma with hearing preservation: a video publication

In this publication, video format is utilized to review the operative technique of retrosigmoid craniotomy for resection of acoustic neuroma with attempted hearing preservation. Steps of the operative procedure are reviewed and salient principles and technical nuances useful in minimizing complications and maximizing efficacy are discussed. The video can be found here: http://youtu.be/PBE5rQ7B0Ls .

Microsurgical localization of the cochlea in the extended middle fossa approach

Objective In the extended middle fossa approach, a portion of the petrous bone known as Kawase's rhomboid can be drilled to expose the posterior fossa through a middle fossa corridor. During this bony resection, the cochlea is placed at risk. The objective of this study was to objectively detail the position of the cochlea in relation to reliable surgical landmarks. Methods Eleven cadaveric specimens were dissected-including six cadaveric heads and five dry temporal bones by means of an anterior petrosectomy with skeletonization of the cochlea. Three anatomic measurements describing the location of the cochlea in relation to the extrapolated intersection of the greater superficial petrosal nerve (GSPN) and facial nerve were recorded. These measurements were then correlated with thin-cut temporal bone computed tomography scans from 25 patients with morphologically normal inner ears. Results In the cadaveric specimens, the anterior border of the membranous basal turn of the cochlea was located an average of 7.56 mm (6.4 to 8.9 mm) anterior to the extrapolated junction of the GSPN and facial nerve, as measured along the course of the GSPN. The medial border of the membranous cochlea (medial margin of basal turn) was located an average of 8.2 mm (6.9 to 8.9 mm) medial to the extrapolated junction of the GSPN and facial nerve, as measured along the course of the facial nerve. The average maximum distance from the extrapolated junction of the GSPN and facial nerve to the membranous cochlea was 9.3 mm (8.2 to 10.3 mm). These anatomic measurements correlated well with radiologic measurements of the same parameters. Conclusion When drilling Kawase's rhomboid, it is useful to locate the extrapolated junction of the GSPN and the facial nerve. Drilling of the anteromedial petrous bone outside of a radius of 12.5 mm from the extrapolated junction of GSPN and facial nerve appears to be associated with a low degree of risk to the cochlear apparatus.

Decreased Rate of CSF Leakage Associated with Complete Reconstruction of Suboccipital Cranial Defects

Background Cerebrospinal fluid (CSF) leakage represents a major source of morbidity following microvascular decompression (MVD) surgery. The objective of this study was to retrospectively assess whether complete versus incomplete reconstruction of the suboccipital cranial defect influences the incidence of CSF leakage following MVD. Methods We reviewed the charts of 100 patients who consecutively underwent MVD for trigeminal neuralgia by two attending neurosurgeons between July 2004 and April 2010. Operative variables including incomplete or complete calvarial reconstruction, primary dural closure or dural closure with adjunct, and use of lumbar drainage were recorded. The effect of complete calvarial reconstruction on the incidence of postoperative CSF leakage was examined using a multivariate logistic regression model. Results Of the 36 patients whose wound closure was reconstructed with a complete cranioplasty, 2 (5.6%) patients experienced a postoperative CSF leak. Of the 64 patients whose wound closure was augmented with an incomplete cranioplasty, 15 (23.4%) experienced a postoperative CSF leak. There was suggestive but inconclusive evidence that the risk of CSF leakage following MVD was smaller with complete reconstruction of calvarial defect than with incomplete reconstruction (two-sided p value = 0.059), after accounting for age, dural closure method, use of lumbar drainage, and previous MVD. Conclusion Complete reconstruction of the suboccipital cranial defect decreases the risk of CSF leakage.

Association between biomechanical parameters and concussion in helmeted collisions in American football: a review of the literature

OBJECT

The authors' goal was to better define the relationship between biomechanical parameters of a helmeted collision and the likelihood of concussion.

METHODS

The English-language literature was reviewed in search of scholarly articles describing the rotational and translational accelerations observed during all monitored impact conditions that resulted in concussion at all levels of American football.

RESULTS

High school players who suffer concussion experience an average of 93.9g of translational acceleration (TA) and 6505.2 rad/s(2) of rotational acceleration (RA). College athletes experience an average of 118.4g of TA and 5311.6 rad/s(2) of RA. While approximately 3% of collisions are associated with TAs greater than the mean TA associated with concussion, only about 0.02% of collisions actually result in a concussion. Associated variables that determine whether a player who experiences a severe collision also experiences a concussion remain hypothetical at present.

CONCLUSIONS

The ability to reliably predict the incidence of concussion based purely on biomechanical data remains elusive. This study provides novel, important information that helps to quantify the relative insignificance of biomechanical parameters in prediction of concussion risk. Further research will be necessary to better define other factors that predispose to concussion.

Experience with 25 years of dorsal root entry zone lesioning at a single institution

BACKGROUND

The authors sought to assess long-term efficacy, surgical morbidity, and postoperative quality of life in patients who have undergone dorsal root entry zone (DREZ) lesioning.

METHODS

We utilized the electronic chart system at our institution to identify patients who underwent DREZ lesioning since 1986. Of the patients that were able to be identified, 19 (12 males and 7 females) patients were able to be contacted at time of data collection. The mean age was 47 years (ranging from 23 to 70 years) with average preoperative pain duration of 12.5 years and average follow-up of 4.9 years.

RESULTS

Of the 19 patients we were able to contact, 7 (37%) patients experienced "excellent" postoperative (complete) pain relief with another 6 (32%) reporting "good" improvement. Three (16%) patients reported "mild" pain relief, while three (16%) patients reported poor results. Sixteen patients (84%) stated they would undergo DREZ lesioning again, if given a choice. Two patients (11%) had objective evidence of a new, mild motor deficit postoperatively. More than half of the patients, who answered, reported "good" quality of life. Two-sample unequal variance t-test showed no statistically significant difference in pain improvement between brachial plexus avulsion and end-zone spinal cord injury pain.

CONCLUSION

With appropriate patient selection, DREZ lesioning is an efficacious and durable procedure that can be performed with low morbidity and good patient outcomes.

Subdural hemorrhage in two high-school football players: post-injury helmet testing

The incidence of catastrophic head injury in American football is at a 30-year high; over 90% of these injuries are secondary to subdural hemorrhage (SDH). At the present time, it is unknown why the incidence of this devastating injury complex continues to rise. Because previous investigations have documented deficiencies in the process of equipment certification at youth and high-school levels, we sought to investigate the adequacy of headgear worn by two athletes who suffered contact-related SDH on the football field and presented to Vanderbilt Children's Hospital between 2009 and 2011. Helmets worn by the struck players at the time of collision (Medium Schutt Air Advantage 7888 and Large Schutt Air XP 7890) were obtained for formal biomechanical testing at a National Operating Committee on the Safety of Athletic Equipment (NOCSAE)-certified facility. Both helmets were found to be compliant with a modified version of the NOCSAE standard ND002-11m12. Based on the aforementioned tests, it can be concluded that headgear worn by both players who suffered SDH was not substandard, as defined by contemporary helmet quality assurance criteria. To the authors' knowledge, this is the first published report of helmet testing following sports-related helmeted collisions resulting in severe traumatic intracranial injuries.

Structural brain injury in sports-related concussion

Object

Sports-related concussions (SRCs) represent a significant and growing public health concern. The vast majority of SRCs produce mild symptoms that resolve within 1–2 weeks and are not associated with imaging-documented changes. On occasion, however, structural brain injury occurs, and neurosurgical management and intervention is appropriate.

Methods

A literature review was performed to address the epidemiology of SRC with a targeted focus on structural brain injury in the last half decade. MEDLINE and PubMed databases were searched to identify all studies pertaining to structural head injury in sports-related head injuries.

Results

The literature review yielded a variety of case reports, several small series, and no prospective cohort studies.

Conclusions

The authors conclude that reliable incidence and prevalence data related to structural brain injuries in SRC cannot be offered at present. A prospective registry collecting incidence, management, and follow-up data after structural brain injuries in the setting of SRC would be of great benefit to the neurosurgical community.

Response to acute concussive injury in soccer players: is gender a modifying factor?

OBJECT

Several studies have suggested a gender difference in response to sports-related concussion (SRC). The Concussion in Sport group did not include gender as a modifying factor in SRC, concluding that the evidence at that point was equivocal. In the present study the authors endeavored to assess acute neurocognitive and symptom responses to an SRC in equivalent cohorts of male and female soccer players. The authors hypothesized that female athletes would experience greater levels of acute symptoms and neurocognitive impairment than males.

METHODS

Baseline symptom and neurocognitive scores were determined in 40 male and 40 female soccer players by using the Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) scale prior to any SRC. After sustaining an SRC, each athlete completed postconcussion ImPACT tests and was carefully matched on a wide array of biopsychosocial variables. Baseline symptom and neurocognitive test scores were compared, and their acute symptoms and neurocognitive responses to concussive injury were assessed.

RESULTS

Specific a priori hypotheses about differences between males and females at baseline and at postconcussion measurements of verbal and visual memory ImPACT scores were evaluated according to simple main effects of the gender variable and according to baseline-to-postconcussion main effect and interaction of 2 × 2 split-plot ANOVA. Neither the interaction nor the main effects nor the simple main effects for either ImPACT variable were found to be statistically significant. Exploratory ANOVAs applied to the remaining ImPACT variables of visualmotor speed, reaction time, impulse control, and symptom total scores revealed only a single statistically significant baseline-to-postconcussion main effect for the symptom total.

CONCLUSIONS

The results failed to replicate prior findings of gender-specific baseline neurocognitive differences in verbal and visual memory. The findings also indicated no differential gender-based acute response to concussion (symptoms or neurocognitive scores) among high school soccer players. The implications of these findings for the inclusion of gender as a modifying factor in this tightly matched cohort are addressed. Potential explanations for the null findings are discussed.

Recovery from sports-related concussion: Days to return to neurocognitive baseline in adolescents versus young adults

BACKGROUND

Sports-related concussions (SRC) among high school and collegiate athletes represent a significant public health concern. The Concussion in Sport Group (CIS) recommended greater caution regarding return to play with children and adolescents. We hypothesized that younger athletes would take longer to return to neurocognitive baseline than older athletes after a SRC.

METHODS

Two hundred adolescent and young adult athletes who suffered a SRC were included in our clinical research cohort. Of the total participants, 100 were assigned to the 13-16 year age group and 100 to the 18-22 year age group and were matched on the number of prior concussions. Each participant completed baseline and postconcussion neurocognitive testing using the Immediate Post-Concussion assessment and Cognitive Testing (ImPACT) test battery. Return to baseline was defined operationally as post-concussion neurocognitive and symptom scores being equivalent to baseline using reliable change index (RCI) criteria. For each group, the average number of days to return to cognitive and symptom baseline were calculated. Independent sample t-tests were used to compare the mean number of days to return to baseline.

RESULTS

Significant differences were found for days to return to baseline between 13-16 year olds and 18-22 year olds in three out of four neurocognitive measures and on the total symptom score. The average number of days to return to baseline was greater for 13-16 year olds than for 18-22 year olds on the following variables: Verbal memory (7.2 vs. 4.7, P = 0.001), visual memory (7.1 vs. 4.7, P = 0.002), reaction time (7.2 vs. 5.1 P = 0.01), and postconcussion symptom scale (8.1 vs. 6.1, P = 0.026). In both groups, greater than 90% of athletes returned to neurocognitive and symptom baseline within 1 month.

CONCLUSIONS

Our results in this clinical research study show that in SRC, athletes 13-16 years old take longer to return to their neurocognitive and symptom baselines than athletes 18-22 years old.