The Development of Skull Base Surgery as a Discipline: Remembrances of Dr Jon H. Robertson.

Skull base surgery is a young surgical subspecialty currently led by its second generation of surgeons. At present, there is no literature that narrates the connection of the present to the past. An extended interview was held with Dr Jon H. Robertson, who helped establish the subspecialty in Memphis, TN, to aid in identifying and connecting sentinel events and key figures in the development of the discipline. The field drastically evolved during his era of practice (1975-present), with the advent of advanced imaging and technology, as well as the emergence of multidisciplinary skull base surgical teams. The intersection of the careers of Jon H. Robertson, James T. Robertson, Gale Gardner, Edwin Cocke, John Shea, Jr., and Jerrall Crook in Memphis catalyzed the standardization of a multidisciplinary approach to cranial base pathology. We report the findings of Dr Jon H. Robertson's extended interview, told against the backdrop of the history of the subspecialty. The story of the development of skull base surgery is told from the unique perspective of one who lived and shaped a pivotal segment in this historical timeline.

A Scoping Review of Professionalism in Neurosurgery.

BACKGROUND AND OBJECTIVES: The Accreditation Council for Graduate Medical Education's Milestones provides a foundation for professionalism in residency training. Specific professionalism concepts from neurosurgery could augment and expand milestones for the specialty. We reviewed the current literature and identified professionalism concepts within the context of neurosurgical practice and training. METHODS: We used a scoping review methodology to search PubMed/MEDLINE and Scopus and identify English-language articles with the search terms "professionalism" and "neurosurgery." We excluded articles that were not in English, not relevant to professionalism within neurosurgery, or could not be accessed. Non-peer-reviewed and qualitative publications, such as commentaries, were included in the review. RESULTS: A total of 193 articles were included in the review. We identified 6 professionalism themes among these results: professional identity (n = 53), burnout and wellness (n = 51), professional development (n = 34), ethics and conflicts of interest (n = 27), diversity and gender (n = 19), and misconduct (n = 9). CONCLUSION: These 6 concepts illustrate concerns that neurosurgeons have concerning professionalism. Diversity and gender, professional identity, and misconduct are not specifically addressed in the Accreditation Council for Graduate Medical Education's Milestones. This review could be used to aid the development of organizational policy statements on professionalism.

Increasing Neurosurgical Resident Research Productivity Through Cultural Shift: Choosing Carrots Over Sticks.

Introduction As part of the Milestones Initiative of the Accreditation Council for Graduate Medical Education (ACGME), residents in neurosurgery are expected to participate in either clinical research or basic science research. Therefore, each neurosurgical training program must offer the support and opportunity to achieve this goal. In 2012, a structured effort to promote a resident culture of research was introduced into the authors' neurosurgery residency training curriculum. This study reviews this experience over the last decade. Methods Data were collected from the authors' departmental neurosurgery website and Scopus to create a database of neurosurgical residents who graduated 10 years before and after 2012 and their publication output. Bibliometric measures were collected for all articles published by residents. Results were compared between residents who graduated before and after the introduction of the research initiative. Results A total of 127 publications were analyzed from 37 residents, constituting 174 authorships. There was a statistically significant increase in the number of publications per resident (P < 0.001), citation number per author (P = 0.002), and author h-index (P < 0.001) after implementing the initiative. There were no significant differences in the pre-residency and baseline demographic variables between the two groups. Conclusion This study relates the experience of initiating a research culture at the authors' neurosurgery training program, which did not emphasize scholarly productivity historically. The effort focused on creating a culture of curiosity as opposed to formal requirements. The results provided evidence that this strategy yielded a significant increase in academic output and impact. These findings have important implications for neurosurgical training programs.

Case Curve: A Novel Web-Based Platform and Mobile Phone Application to Evaluate Surgical Competence in Graduate Medical Education.

BACKGROUND AND OBJECTIVES: Competency-based medical education is well established, yet methods to evaluate and document acquisition of surgical skill remain underdeveloped. We describe a novel web-based application for competency-based surgical education at a single neurosurgical department over a 3-year period. METHODS: We used a web-based application to track procedural and cognitive skills acquisition for neurosurgical residents. This process included self-assessment, resident peer evaluations, evaluations from supervising attending physicians, and blinded video reviews. Direct observation by faculty and video recordings were used to evaluate surgical skill. Cases were subdivided into component skills, which were evaluated using a 5-point scale. The learning curve for each skill was continuously updated and compared with expectations. Progress was reviewed at a monthly surgical skills conference that involved discussion and analysis of recorded surgical performances. RESULTS: During an escalating 3-year pilot from 2019 to 2022, a total of 1078 cases in 39 categories were accrued by 17 resident physicians with 10 neurosurgical faculty who participated as evaluators. A total of 16 251 skill performances in 110 categories were evaluated. The most evaluated skills were those that were common to several types of procedures, such as positioning, hemostasis, and wound closure. The concordance between attending evaluations and resident self-evaluations was 76%, with residents underestimating their performance in 17% of evaluations and overestimating in 7%. CONCLUSION: We developed a method for evaluating and tracking surgical resident skill performance with an application that provides timely and actionable feedback. The data collected from this system could allow more accurate assessments of surgical skills and deeper insights into factors influencing surgical skill acquisition.

Isolated pyocele of anterior clinoid process presenting as a cavernous sinus syndrome.

A 37-year-old man presented with fever, decreased vision in the left eye, a partial left cranial nerve III paresis, and a left cranial nerve VI paresis. Neuro-imaging showed an opacification of a left pneumatised anterior clinoid process. After failing a course of intravenous antibiotics, a craniotomy was performed with exenteration of the cavity and resolution of symptoms. Although rare, a pyocele of a pneumatised anterior clinoid process may cause ocular morbidity and require surgical intervention.

Modified Orbitozygomatic Craniotomy, Anterior Clinoidectomy, and Retrograde Suction Decompression "Dallas Technique" for Large Unruptured Clinoidal-Ophthalmic Segment Aneurysm.

Simple clip trapping may not adequately decompress giant paraclinoidal or ophthalmic artery aneurysms for safe permanent clipping.1-10 Full temporary interruption of the local circulation via clipping of the intracranial carotid artery with concomitant suction decompression via an angiocatheter placed in the cervical internal carotid artery as originally described by Batjer et al3 allows the primary surgeon to use both hands to clip the target aneurysm. Detailed understanding of skull base and distal dural ring anatomy is critical for microsurgical clipping of giant paraclinoid and ophthalmic artery aneurysms.2-4 Microsurgical approaches allow for direct decompression of the optic apparatus as opposed to endovascular coiling or flow diversion that may contribute to increased mass effect.11 We describe the case of a 60-year-old woman who presented with left-sided visual loss, a family history of aneurysmal subarachnoid hemorrhage, and a giant unruptured clinoidal-ophthalmic segment aneurysm with both extradural and intradural components.2 The patient underwent an orbitopterional craniotomy, Hakuba "peeling" of the temporal dura propria from the lateral wall of the cavernous sinus, and anterior clinoidectomy (Video 1). The proximal sylvian fissure was split, the distal dural ring was completely dissected, and the optic canal and falciform ligament were opened. The aneurysm was trapped, and retrograde suction decompression via the "Dallas Technique" was employed for safe clip reconstruction of the aneurysm.3,4 Postoperative imaging showed complete obliteration of the aneurysm, and the patient remained at her neurologic baseline. The technical considerations and literature regarding the suction decompression technique to treat giant paraclinoid aneurysms are reviewed.2-4 The patient and family provided informed consent for the procedure and consented to the publication of her images.

Resection of an anterior spinal cord AVM through a far-lateral approach.

A small arteriovenous malformation near the craniocervical junction with contributions from the anterior spinal artery was discovered in a young developmentally-delayed woman after she presented with altered mental status and evidence of subarachnoid hemorrhage. The malformation could not be completely treated with endovascular therapy, so it was resected through a far-lateral approach. This stereoscopic video demonstrates how to gain the exposure needed to address a lesion in this area. The video can be found here: http://youtu.be/ByjPGm_eXLc .

History, Variations, and Extensions of the Retrosigmoid Approach: Anatomical and Literature Review.

The retrosigmoid approach is the workhorse for posterior fossa surgery. It gives a versatile corridor to tackle different types of lesions in and around the cerebellopontine angle. The term "extended" has been used interchangeably in the literature, sometimes creating confusion. Our aim was to present a thorough analysis of the approach, its history, and its potential extensions. Releasing cerebrospinal fluid from the subarachnoid spaces and meticulous microsurgical techniques allowed for the emergence of the retrosigmoid approach as a unilateral variation of the traditional suboccipital approach. Anatomical landmarks are helpful in localizing the venous sinuses and planning the craniotomy, and Rhoton's rule of three is the key to unlock difficult neurovascular relationships. Extensions of the approach include, among others, the transmastoid, supracerebellar, far-lateral, jugular foramen, and perimeatal approaches. The retrosigmoid approach applies to a broad range of pathologies and, with its extensions, can provide adequate exposure, obviating the need for extensive and complicated approaches.

Determinants of tumor treating field usage in patients with primary glioblastoma: A single institutional experience.

Background: Determinates of tumor treating fields (TTFields) usage in patients receiving combined modality therapy for primary IDH wild-type glioblastoma are currently unknown. Methods: Ninety-one patients underwent maximal debulking surgical resection, completed external beam radiotherapy with concurrent Temozolomide (TMZ), and initiated adjuvant TMZ with or without TTFields. We performed a retrospective analysis of patient, tumor, and treatment-related factors that affected TTFields usage. Results: We identified three TTFields usage subgroups: 32 patients that declined TTFields, 40 patients that started, but had monthly compliance of less than 75% or used it for less than 2 months, and 19 patients who used TTFields for 2 or more months and maintained average monthly compliance greater than 75%. With 26.5 months median follow-up for surviving patients, the 1- and 3-year actuarial overall survival for all patients was 80% and 18%, respectively. On multivariate analysis TTFields use (P = .03), extent of surgical resection (P = 0.02), and MGMT methylation status (P = .01) were significantly associated with overall survival. TTFields usage was explored as a continuous variable and higher average usage was associated with longer overall survival (P = .03). There was no relationship between patient, tumor, or treatment-related factors and a patient's decision to use TTFields. Conclusions: No subgroup of patients was more or less likely to initiate TTFields therapy and no subgroup was more or less likely to use TTFields as prescribed. The degree of TTFields compliance may be associated with improved survival independent of other factors.

The Asterion-to-Transverse Process of the Atlas Line as a Surgical Landmark.

Introduction Proposed landmarks to predict the anatomical location and trajectory of the sigmoid sinus have varying degrees of reliability. Even with neuronavigation technology, landmarks are crucial in planning and performing complex approaches to the posterolateral skull base. By combining two major dependable structures-the asterion (A) and transverse process of the atlas (TPC1)-we investigate the A-TPC1 line in relation to the sigmoid sinus and in partitioning surgical approaches to the region. Methods We dissected six cadaveric heads (12 sides) to expose the posterolateral skull base, including the mastoid and suboccipital bone, TPC1 and suboccipital triangle, distal jugular vein and internal carotid artery, and lower cranial nerves in the distal cervical region. We inspected the A-TPC1 line before and after drilling the mastoid and occipital bones and studied the relationship of the sigmoid sinus trajectory and major muscular elements related to the line. We retrospectively reviewed 31 head and neck computed tomography (CT) angiograms (62 total sides), excluding posterior fossa or cervical pathologies. Bone and vessels were reconstructed using three-dimensional segmentation software. We measured the distance between the A-TPC1 line and sigmoid sinus at different levels: posterior digastric point (DP), and maximal distances above and below the digastric notch. Results A-TPC1 length averaged 65 mm and was posterior to the sigmoid sinus in all cadaver specimens, coming closest at the level of the DP. Using the transverse-asterion line as a rostrocaudal division and skull base as a horizontal plane, we divided the major surgical approaches into four quadrants: distal cervical/extreme lateral and jugular foramen (anteroinferior), presigmoid/petrosal (anterosuperior), retrosigmoid/suboccipital (posterosuperior), and far lateral/foramen magnum regions (posteroinferior). Radiographically, the A-TPC1 line was also posterior to the sigmoid sinus in all sides and came closest to the sinus at the level of DP (mean, 7 mm posterior; range, 0-18.7 mm). The maximal distance above the DP had a mean of 10.1 mm (range, 3.6-19.5 mm) and below the DP 5.2 mm (range, 0-20.7 mm). Conclusion The A-TPC1 line is a helpful landmark reliably found posterior to the sigmoid sinus in cadaveric specimens and radiographic CT scans. It can corroborate the accuracy of neuronavigation, assist in minimizing the risk of sigmoid sinus injury, and is a useful tool in planning surgical approaches to the posterolateral skull base, both preoperatively and intraoperatively.

Endoscopic Endonasal Treatment of a Sinonasal Vascular Neoplasm in the Postnatal Period: Case Report and Review of Literature.

OBJECTIVES: Congenital vascular lesions commonly present in the head and neck, and most are managed conservatively. Location and rapid growth, however, may necessitate surgical intervention. Endoscopic endonasal surgery (EES) in the pediatric population has emerged as a viable option in treating sinonasal and skull base lesions. Utilizing these techniques in newborns carries unique challenges. The objective of this report is to describe the successful use of direct intralesional embolization followed by endoscopic endonasal resection of a venous malformation in a postnatal patient. METHODS: We reviewed the case reported and reviewed the pertinent literature. RESULTS: A 6-week-old infant was found to have a large right-sided sinonasal lesion confirmed as a venous malformation. Rapid growth, impending orbital compromise, and potential long-term craniofacial abnormalities demanded the need for urgent surgical intervention. Risk of bleeding was mitigated with direct intralesional embolization. Immediately afterward, the patient underwent endoscopic endonasal resection of the lesion. EES in the very young presents multiple challenges both anatomically and behaviorally. A multidisciplinary approach lead to a successful outcome. CONCLUSION: We report a case of a 6-week-old infant, the youngest reported patient to the authors' knowledge, who successfully underwent direct intralesional embolization followed by endoscopic endonasal resection of a sinonasal vascular malformation. This report highlights the challenges of this technique in the very young and demonstrates it as a viable treatment strategy for sinonasal vascular anomalies in this population.

Optimizing the residency application process: insights from neurological surgery during the pandemic virtual application cycle.

OBJECTIVE: In this article, the authors describe the impact of the COVID-19 virtual match cycle and discuss approaches to optimize future cycles through applicant and neurosurgical education leadership insights. METHODS: Anonymous surveys of neurosurgery program leaders (program directors and program chairs), program administrators (PAs), and 2020-2021 neurosurgery residency match applicants were distributed by the SNS, in conjunction with the Association of Resident Administrators in Neurological Surgery and AANS Young Neurosurgeons Committee. RESULTS: Responses were received from 77 (67.0%) of 115 PAs, 119 (51.7%) of 230 program leaders, and 124 (44.3%) of 280 applicants representing geographically diverse regions. During the virtual application cycle relative to the previous year, programs received more Electronic Residency Application Service applications (mean 314.8 vs 285.3, p < 0.0001) and conducted more applicant interviews (mean 45.2 vs 39.9, p = 0.0003). More than 50% of applicants applied to > 80 programs; 60.3% received ≤ 20 interview invitations, and 9% received > 40 invitations. Overall, 65% of applicants completed ≤ 20 interviews, whereas 34.7% completed > 20 interviews. Program leaders described one 4-week home subinternship (93.3%) and two 4-week external subinternships (68.9%) as optimal neurosurgical exposure; 62.8% of program leaders found the standardized letter of recommendation template to be somewhat (47.5%) or significantly (15.3%) helpful. Applicants, PAs, and program leaders all strongly preferred a hybrid model of in-person and virtual interview options for future application cycles over all in-person or all virtual options. Ninety-three percent of applicants reported matching within their top 10-ranked programs, and 52.9% of programs matched residents within the same decile ranking as in previous years. CONCLUSIONS: Optimizing a national strategy for the neurosurgery application process that prioritizes equity and reduces costs, while ensuring adequate exposure for applicants to gain educational opportunities and evaluate programs, is critical to maintain a successful training system.

Erratum: Skull Base Registries: A Roadmap.

[This corrects the article DOI: 10.1055/a-1934-9191.].

Skull Base Registries: A Roadmap.

Hospitals, payors, and patients increasingly expect us to report our outcomes in more detail and to justify our treatment decisions and costs. Although there are many stakeholders in surgical outcomes, physicians must take the lead role in defining how outcomes are assessed. Skull base lesions interact with surrounding anatomy to produce a complex spectrum of presentations and surgical challenges, requiring a wide variety of surgical approaches. Moreover, many skull base lesions are relatively rare. These factors and others often preclude the use of prospective randomized clinical trials, thus necessitating alternate methods of scientific inquiry. In this paper, we propose a roadmap for implementing a skull base registry, along with expected benefits and challenges.

Retrospective Review of Surgical Site Infections after Endoscopic Endonasal Sellar and Parasellar Surgery: Multicenter Quality Data from the North American Skull Base Society.

Introduction Transnasal access to the anterior skull base provides a minimally invasive approach for sellar and parasellar masses compared with its open counterparts. The unique microbiome of the sinonasal mucosa provides distinct challenges not encountered with other cranial approaches. The use of antibiotics in these cases has not been standardized, and data remain scarce regarding infectious outcomes. Methods We conducted a multicenter retrospective analysis of shared quality data points for the endoscopic endonasal approach (EEA) for pituitary adenomas, along with other sellar and parasellar region masses that were included by participating institutions. Patient and operative characteristics, perioperative and postoperative antibiotic regimens and their durations, intraoperative and postoperative cerebrospinal fluid leak, and onset of postoperative meningitis and sinusitis were compared. Results Fifteen institutions participated and provided 6 consecutive months' worth of case data. Five hundred ninety-three cases were included in the study, of which 564 were pituitary adenomectomies. The incidences of postoperative meningitis and sinusitis were low (0.67 and 2.87% for all pathologies, respectively; 0.35% meningitis for pituitary adenomas) and did not correlate with any specific antibiotic regimen. Immunocompromised status posed an increased odds of meningitis in pituitary adenomectomies (28.6, 95% confidence interval [1.72-474.4]). Conclusions The results show no clear benefit to postoperative antimicrobial use in EEA, with further larger studies needed.

Resection of a Recurrent Cervicomedullary Junction Fibromyxoid Sarcoma through a Far Lateral Approach.

Objectives This study describes a far lateral approach for the resection of a recurrent fibromyxoid sarcoma involving the ventrolateral brainstem, with emphasis on the microsurgical anatomy and technique. Design A far lateral craniotomy is performed in the lateral decubitus position and the transverse and sigmoid sinuses exposed. After opening the dura, sutures are placed to allow gentle mobilization of the sinuses. The recurrent tumor is immediately visible. The involved dura is resected and aggressive internal debulking is performed. Subarachnoid dissection gives access to the lower cranial nerves. The tumor is dissected off the affected portions of the brainstem. A dural graft is used to reconstitute the dura. Photographs of the region are borrowed from Dr. Rhoton's laboratory to illustrate the microsurgical anatomy. Participants The senior author performed the surgery. The video was edited by Dr. V.N. chart review, and literature review were performed by Drs. W.M. and J.B. Outcome measures Outcome was assessed with the extent of resection and postoperative neurological function. Results A near gross total resection of the lesion was achieved. The patient developed a left vocal cord paresis, but her voice was improving at 3-month follow-up. Conclusion Understanding the microsurgical anatomy of the craniocervical junction and ventrolateral brainstem and meticulous microneurosurgical technique are necessary to achieve adequate resection of lesions involving the ventrolateral brainstem. The far lateral approach provides an adequate corridor to this region. The link to the video can be found at: https://youtube/uYEhgPbgrTs .

Robotic-Assisted Tubular Transoral Parapharyngeal Approach to the Ventral Craniovertebral Junction.

BACKGROUND: Transoral robotic surgery (TORS) has become a routine technique for treating benign and malignant lesions of the oropharynx with the advantage of reducing morbidity compared to open surgical techniques. However, TORS has not been used routinely for accessing lesions of the spine. OBJECTIVE: To describe how TORS can be used to access spinal lesions. METHODS: We describe our technique of accessing the parapharyngeal space using the robotic technique, and then dissecting the prevertebral muscles to expose the ventral craniovertebral junction. Tubular retraction with endoscopic visualization is then employed for surgical resection. We then report a case of a 14-yr-old competitive athlete who presented with an osseous lesion of C1, which underwent resection using this novel TORS approach. RESULTS: Our patient underwent successful resection of a lateral C1 osteoid osteoma utilizing a combined TORS/endoscopic approach. She tolerated soft diet immediately and was discharged on postoperative day 2. Postoperative imaging revealed complete resection of the lesion, and she returned to competitive athletics within 6 wk. CONCLUSION: Utilizing this novel, robotic-assisted approach can definitively treat osseous cervical spine lesions while reducing morbidity, allowing for early return to normal diet and minimizing overall length of hospital stay.

Resident operative experience in pediatric neurosurgery across the United States.

OBJECTIVE: Neurosurgical residents receive exposure to the subspecialty of pediatric neurosurgery during training. The authors sought to determine resident operative experience in pediatric neurosurgery across Accreditation Council for Graduate Medical Education (ACGME)-accredited neurosurgical programs. METHODS: During 2018-2019, pediatric neurosurgical case logs for recent graduates or current residents who completed their primary pediatric exposure were collected from US continental ACGME training programs. Using individual resident reports and procedure designations, operative volumes and case diversity were analyzed collectively, according to training site characteristics, and also correlated with the recently described Resident Experience Score (RES). RESULTS: Of the 114 programs, a total of 316 resident case logs (range 1-19 residents per program) were received from 86 (75%) programs. The median cumulative pediatric case volume per resident was 109 (IQR 75-161). Residents at programs with a pediatric fellowship reported a higher median case volume (143, IQR 96-187) than residents at programs without (91, IQR 66-129; p < 0.0001). Residents at programs that outsource their pediatric rotation had a lower median case volume (84, IQR 52-114) compared with those at programs with an in-house experience (117, IQR 79-170; p < 0.0001). The case diversity index among all programs ranged from 0.61 to 0.80, with no statistically significant differences according to the Accreditation Council for Pediatric Neurosurgery Fellowships designation or pediatric experience site (p > 0.05). The RES correlated moderately (r = 0.44) with median operative volumes per program. A program's annual pediatric operative volume and duration of pediatric experience were identified as significant predictive factors for median resident operative volume. CONCLUSIONS: Resident experience in pediatric neurosurgery is variable within and between programs. Case volumes are generally higher for residents at programs with in-house exposure and an accredited fellowship, but case diversity is relatively uniform across all programs. RES provides some insight on anticipated case volume, but other unexplained factors remain.

A prospective evaluation and literature review of levetiracetam use in patients with brain tumors and seizures.

To determine the safety and tolerability of IV and oral levetiracetam monotherapy for seizures in brain tumor patients following resection. Brain tumor patients undergoing neurosurgery with >or=1 seizure within the preceding month prior to surgery were enrolled to receive intravenous levetiracetam for a minimum of 48 h, transitioned to oral levetiracetam at the same dose, and followed for 1-month after discharge. Patients were assessed daily in the hospital, provided with a seizure diary, and supplied with 30 days of levetiracetam upon discharge. Study patients were telephoned weekly to assess their cognitive status and seizure frequency. Of the 17 patients enrolled, the baseline seizure types were tonic clonic, partial, and complex partial with secondary generalization. The most common type of tumor was glioblastoma multiforme. Levetiracetam was well tolerated with no medication discontinuation during the study period. Adverse effects reported were somnolence, nausea/vomiting, headache, and insomnia. Eleven patients were evaluable for TICS scores (64.7%) with an average score of 33.3. Two patients were deemed to be cognitively impaired (18.2%). Eleven of twelve patients (91.7%) that completed the study period achieved a >or=50% reduction in their number of seizures. A total of 92 drug interactions were avoided (P = 0.0016) with dexamethasone, acetaminophen, and fentanyl being the most common. Levetiracetam monotherapy was found to be safe and tolerable in this patient population. Nearly all patients achieved a >or=50% reduction in seizure frequency post-op with levetiracetam monotherapy. Levetiracetam also has the potential for less drug interactions compared to phenytoin in these patients.