Walk the Line. The Surgical Highways to the Craniovertebral Junction in Endoscopic Approaches: A Historical Perspective

The Economic Burden of Management of Pituitary Adenomas: A Propensity-Score-Matched Cost Analysis

IMPORTANCE

Pituitary adenomas (PAs) present a notable economic burden on healthcare systems due to their management's reliance on multimodal, often costly interventions.

OBJECTIVE

To determine total and relative healthcare costs for PAs at Ontario-based institutions.

DESIGN

A retrospective, propensity-score-matched cohort analysis.

SETTING

Ontario, Canada, encompassing public healthcare facilities and covering costs over a 6-year study period.

PARTICIPANTS

Adults diagnosed with PA (n = 1675) between April 1, 2013, and March 31, 2019, compared to a general population cohort and a hospitalized control cohort matched on demographics and health factors.

INTERVENTION/EXPOSURES

Analysis of healthcare cost components (inpatient, outpatient, and diagnostic services) and cost trajectories postsurgery for PAs.

MAIN OUTCOME MEASURES

Primary outcome was total annualized healthcare costs for patients with PA relative to the general and hospitalized cohorts. Relative costs were estimated using a negative binomial regression model.

RESULTS

Of 1675 patients with PA, total annualized costs were $49,992. Highest total costs were associated with inpatient hospitalization ($24,796) and physician services/diagnostic evaluations ($20,075). After propensity score matching, patients with PA had 12.7 times higher costs [95% confidence interval (CI) (10.9, 14.8), P < .0001] during the preadmission/admission period, which remained elevated postoperatively (P < .05). Total costs did not differ between patients with PA and the hospitalized cohort [RR 0.97, 95% CI (0.92, 1.03); P = .3271] in the preadmission/admission period; however, follow-up costs were 37% lower for patients with PA in the 1st follow-up year [RR 0.63, 95% CI (0.51, 0.77); P < .0001], and up to 50% lower by the 5th year [RR 0.50, 95% CI (0.36, 0.68); P < .0001].

CONCLUSIONS

This study provided a comprehensive assessment of the economic burden of PAs on the publicly-funded healthcare system. Patients with PA had higher annualized total costs across all observed time periods compared to the general population and lower annualized total costs compared to patients admitted to a surgical ward.

RELEVANCE

This study highlights the financial impact of PA management on healthcare resources and provides a basis for future research aimed at cost-efficiency improvements in long-term PA care.

Not Every Size Fits All: Surgical Corridors for Clival and Cervical Chordomas-A Systematic Review of the Literature and Illustrative Cases

Introduction. Clival chordomas represent a rare but clinically significant subset of skull base tumors, characterized by a locally aggressive nature and a location in proximity to vital neurovascular structures. Surgical resection, often combined with adjuvant therapies, remains the cornerstone of clival chordoma treatment, and various approaches and techniques have evolved to maximize tumor removal while preserving neurological function. Recent advancements in skull base surgery, imaging, and adjuvant therapies have improved outcomes by reducing morbidity and thus enhancing long-term survival. Methods and Results. We have conducted a systematic review on PubMed/Medline following PRISMA guidelines regarding indications, the extent of resection (EOR), and complication rates. Then, we present three illustrative cases from our personal experience, which started 25 years ago with CVJ instrumentation procedures and 15 years ago with anterior decompressive transmucosal procedures performed with the aid of an operative microscope, an endoscope, and neuroradiological monitoring. Conclusions. Traditionally, the transoral approach (TOA) is the most frequently used corridor for accessing the lower clivus and the anterior craniovertebral junction (CVJ), without the need to mobilize or retract neural structures; however, it is associated with a high rate of complications. The endonasal approach (EEA) provides access to the anterior CVJ as well as to the lower, middle, and superior clivus, decreasing airway and swallowing morbidity, preserving palatal function, decreasing postoperative pain, and reducing the incidence of tracheostomy. The submandibular retropharyngeal approach (SRA) allows unique access to certain cervical chordomas, which is better suited when the lesion is located below the clivus and in the midline.

Endoscopy-assisted high cervical anterolateral retropharyngeal approach to clivus: a cadaveric study

Introduction

The surgical management of pathologies involving the clivus and craniocervical junction has always been considered a complex procedure because of the deeply located surgical targets and the surrounding complex neural and vascular anatomical structures. The most commonly used approaches to reach this area are the transnasal, transoral, and transcervical approaches.

Material and Methods

This approach was performed unilaterally on five cadaver heads and bilaterally on one cadaver head.

Results

We described a modified endoscope-assisted high cervical anterolateral retropharyngeal approach in which each stage of the procedure was demonstrated on human cadavers in a step-by-step manner using endoscopic camera views. This approach was broken down into nine steps. The neurovascular structures encountered at each step and their relationships with each other are demonstrated.

Discussion

The advantages and disadvantages of our modified approach were compared to the conventional transcervical, transoral, and endoscopic endonasal approaches.

Evolution, Current Trends, and Latest Advances of Endoscopic Spine Surgery

Background: The aging of the population in developing and developed countries has led to a significant increase in the health burden of spinal diseases. These elderly patients often have a number of medical comorbidities due to aging. The need for minimally invasive techniques to address spinal disorders in this elderly population group cannot be stressed enough. Minimally invasive spine surgery (MISS) has several proven benefits, such as minimal muscle trauma, minimal bony resection, lesser postoperative pain, decreased infection rate, and shorter hospital stay. Methods: A comprehensive search of the literature was performed using PubMed. Results: Over the past 40 years, constant efforts have been made to develop newer techniques of spine surgery. Endoscopic spine surgery is one such subset of MISS, which has all the benefits of modern MISS. Endoscopic spine surgery was initially limited only to the treatment of lumbar disc herniation. With improvements in optics, endoscopes, endoscopic drills and shavers, and irrigation pumps, there has been a paradigm shift. Endoscopic spine surgery can now be performed with high magnification, thus allowing its application not only to lumbar spinal stenosis but also to spinal fusion surgeries and cervical and thoracic pathology as well. There has been increasing evidence in support of these newer techniques of spine surgery. Conclusions: For this report, we studied the currently available literature and outlined the historical evolution of endoscopic spine surgery, the various endoscopic systems and techniques available, and the current applications of endoscopic techniques as an alternative to traditional spinal surgery.

Craniovertebral Junction Surgical Approaches: State of Art

Surgical approaches directed toward craniovertebral junction (CVJ) can be addressed to the ventral, dorsal, and lateral aspects through a variety of 360° surgical corridors Herein, we report features, advantages, and limits of the updated technical support in CVJ surgery in clinical setting and dissection laboratories enriched by our preliminary surgical results of the simultaneous application of O-arm intraoperative neuronavigation and imaging system along with the 3D-4K EX in TOA for the treatment of CVJ pathologies.In the past 4 years, eight patients harboring CVJ compressive pathologies underwent one-step combined anterior neurosurgical decompression and posterior instrumentation and fusion technique with the aid of exoscope and O-arm. In our equipped Cranio-Vertebral Junction Laboratory, we use fresh cadavers (and injected "head and neck" specimens) whose policy, protocols, and logistics have already been elucidated in previous works. Five fresh-frozen adult specimens were dissected adopting an FLA. In these specimens, a TOA was also performed, as well as a neuronavigation-assisted comparison between transoral and transnasal explorable distances.A complete decompression along with stable instrumentation and fusion of the CVJ was accomplished in all the cases at the maximum follow-up (mean: 25.3 months). In two cases, the O-arm navigation allowed the identification of residual compression that was not clearly visible using the microscope alone. In four cases, it was not possible to navigate C1 lateral masses and C2 isthmi due to the angled projection unfitting with the neuronavigation optical system, so misleading the surgeon and strongly suggesting changing surgical strategy intraoperatively. In another case (case 4), it was possible to navigate and perform both C1 lateral masses and C2 isthmi screwing, but the screw placement was suboptimal at the immediate postoperative radiological assessment. In this case, the hardware displacement occurred 2 months later requiring reoperation.

Combined Transoral Exoscope and OARM-Assisted Approach for Craniovertebral Junction Surgery. New Trends in an Old-Fashioned Approach

BACKGROUND

The introduction of recent innovations in the field of intraoperative imaging and neuronavigation, such as the O-arm StealthStation, allows for obtaining crucial intraoperative data by performing safer and controlled surgical procedures. As part of the improvement of surgical visual magnification and wide expansion of surgical corridors, the 3D 4 K exoscope (EX) has nowadays become an interesting and useful tool. The transoral approach (TOA) is the historical gold-standard direct microsurgical route to ventral craniovertebral junction (CVJ).

METHODS

We herein report our experience, consisting of ten cases via TOA concerning the simultaneous application of an O-arm with a StealthStation navigation system (Medtronic, Memphis, TN) and an imaging system, along with the 3D 4 K exoscopes in the TOA, for the treatment of CVJ pathologies.

RESULTS

No intraoperative neurophysiological changes or postoperative infections occurred, but neurological improvement was evident in all the patients. A complete decompression and a stable instrumentation and fusion of the CVJ were accomplished in all cases at the maximum follow-up time.

CONCLUSIONS

With EX, the role of the surgeon becomes self-sufficient with better individual surgical freedom compared to endoscopic surgery and excellent 3D vision and magnification. O-arms offer absolutely reliable intraoperative support for more-effective CVJ decompression. Nevertheless, with O-arm-assisted neuronavigation, it can be difficult to navigate C1 lateral masses and C2 isthmi, and converting 3D into 2D real-time navigation can be quite complicated. Finally, the combination of an EX with an O-arm appears more time-consuming compared to the old-fashion one.

The endoscopic transnasal approach to the lesions of the craniocervical junction: two case reports

The endoscopic endonasal approach (EEA) to the craniovertebral junction (CVJ) has recently been considered a safer alternative and less invasive approach than the traditional transoral approach because the complications associated with the latter are avoided or minimized. Here, we present two challenging cases of CVJ pathologies. The first case involved os odontoideum associated with anterior displacement of the occipitocervical junction where the EEA was used, followed by C0-C1-C2 fusion using a posterior approach to decompress the CVJ, and was complicated by rhinorrhea and Candida albicans meningitis. The second case involved basilar invagination with syringomyelia previously treated using a posterior approach, where aggravation of neuropathic symptoms required combined treatment with EEA and occipitocervical fusion of C0-C2-C3-C4, with the postoperative course challenged by operative site infection requiring drainage with debridement and antibiotic therapy. The EEA is an alternative approach for accessing the CVJ in well-selected patients. Knowledge of EEA complications is crucial for the optimal care of patients.

Endoscopic Transoral Approach for Resection of Basal Cell Adenoma Arising in Parapharyngeal Space

Objectives  The clinical and radiological characteristics of the basal cell adenoma (BCA) and its association with the internal carotid artery (ICA) in the parapharyngeal space (PPS), have not been sufficiently explored. This study aims to analyze the characteristics of patients with BCA arising in the PPS and to evaluate the feasibility of a total resection via an endoscopic transoral corridor. Design and Main Outcome Measures  The clinical, radiological, and histopathological characteristics of four patients with BCA arising in the PPS were retrospectively analyzed. The endoscopic transoral approach was performed for resection of BCA. Its technical nuances, perioperative comorbidities, and outcomes are introduced. Results  The clinical presentation, symptoms, and signs of patients with BCA are variable. The tumor was lateral to the ICA in two patients and anterior to the ICA in the remaining two. All four BCA were successfully removed en bloc ( n  = 3) or by piecemeal ( n  = 1) via an endoscopic transoral approach. The ICA was not injured, and no additional nerve damage, venous bleeding, postoperative infection, or salivary gland fistula were encountered in any of the four patients. Cystic degeneration is the predominant appearance of BCA on MRI; however, they are difficult to differentiate from other lesions arising in the PPS. No recurrence was detected at the time of the study analysis. Conclusion  BCA of the PPS could have variable relationships with the ICA. An endoscopic transoral approach can provide an adequate corridor for total resection of BCA in PPS with seemingly low morbidity.

Multidisciplinary approach to the craniovertebral junction. Historical insights, current and future perspectives in the neurosurgical and otorhinolaryngological alliance

Historically considered as a nobody’s land, craniovertebral junction (CVJ) surgery or specialty recently gained high consideration as symbol of challenging surgery as well as selective top level qualifying surgery. The alliance between Neurosurgeons and Otorhinolaringologists has become stronger in the time. CVJ has unique anatomical bone and neurovascular structures architecture. It not only separates from the subaxial cervical spine but it also provides a special cranial flexion, extension, and axial rotation pattern. Stability is provided by a complex combination of osseous and ligamentous supports which allows a large degree of motion. The perfect knowledge of CVJ anatomy and physiology allows to better understand surgical procedures of the occiput, atlas and axis and the specific diseases that affect the region. Although many years passed since the beginning of this pioneering surgery, managing lesions situated in the anterior aspect of the CVJ still remains a challenging neurosurgical problem. Many studies are available in the literature so far aiming to examine the microsurgical anatomy of both the anterior and posterior extradural and intradural aspects of the CVJ as well as the differences in all the possible surgical exposures obtained by 360° approach philosophy. Herein we provide a short but quite complete at glance tour across the personal experience and publications and the more recent literature available in order to highlight where this alliance between Neurosurgeon and Otorhinolaringologist is mandatory, strongly advisable or unnecessary.

Combined transoral exoscope and OArm-assisted approach for craniovertebral junction surgery: Light and shadows in single-center experience with improving technologies

Background

The introduction of recent innovations in the field of intraoperative imaging and neuronavigation, such as OArm Stealth Station, allows to obtain crucial intraoperative data by performing safer and controlled surgical procedures. As part of the improvement of surgical visual magnification and wide expansion of surgical corridors, the 3D-4K exoscope (EX) represents nowadays an interesting and useful tool. Transoral approach (TOA) represents the historical gold standard direct microsurgical route to ventral craniovertebral junction (CVJ).

Methods

We herein report a preliminary experience on 6 cases of 33 patients operated by TOA concerning the simultaneous application of OArm with Stealth Navigation system (Medtronic, Memphis, TN) and imaging system along with the 3D-4K EXs in TOA for the treatment of CVJ pathologies.

Results

Neither intraoperative neurophysiological changes nor postoperative infections occurred, but a neurological improvement was evident in all the patients. A complete decompression along with stable instrumentation and fusion of the CVJ was accomplished in all cases at the maximum follow-up (mean: 16.8 months).

Conclusions

With EX, the role of surgeon become self-sufficient with a better individual surgical freedom compared to endoscopic surgery and excellent 3D vision and magnification. OArm allows an absolutely reliable intraoperative support for a more effective CVJ decompression. Nevertheless, with OArm-assisted neuronavigation, it can be difficult to navigate C1 lateral masses and C2 isthmi, and to convert 3D into 2D real-time navigation, it can become quite complicate. Finally, the association of EX and OArm appears more time consuming compared to the old fashion one.

Navigation-Guided Measurement of the Inferior Limit Through the Endonasal Route to the Craniovertebral Junction

BACKGROUND

The endoscopic endonasal approach (EEA) has been accepted as an alternative option for diseases at the craniovertebral junction. However, the inferior destination through the endoscopic endonasal approach is anatomically higher than that of the transoral approach. Therefore, preoperative assessment of accessibility is mandatory for appropriate selection of indication. Using a navigation system, we examined the inferior limit through the endonasal route and evaluated the relationships between surrounding anatomicl structures and the lowest point.

METHODS

This study included patients who underwent endoscopic transsphenoidal surgery for intrasellar lesions at our hospital (N = 23). At the start of surgery, the lowest point (target point [TP]) was marked with a straight probe under guidance of the navigation system. We measured 4 parameters on preoperative computed tomography: nasal length, hard palate length, anterior-posterior diameter of the nasopharynx, and nasopalatine angle. Patients were classified into groups depending on whether the TP was at or above (group A) or below (group B) the hard palatine line.

RESULTS

TPs were above the hard palatine line in 15 patients (group A) and below the hard palatine line in 8 patients (group B). No TPs reached the nasopalatine line. Nasal length (P = 0.03) and nasopalatine angle (P = 0.01) were larger in group B than in group A. There were no significant differences in anterior-posterior diameter of the nasopharynx or hard palate length.

CONCLUSIONS

The hard palatine line is a reliable parameter for assessing the inferior limit of the endoscopic endonasal approach. Nostril size affects accessibility with surgical instruments.

Overview of Minimally Invasive Spine Surgery

Minimally invasive spine surgery (MISS) has continued to evolve over the past few decades, with significant advancements in technology and technical skills. From endonasal cervical approaches to extreme lateral lumbar interbody fusions, MISS has showcased its usefulness across all practice areas of the spine, with unique points of access to avoid pertinent neurovascular structures. Adult spine deformity has also recognized the importance of minimally invasive techniques in its ability to limit complications and to provide adequate sagittal alignment correction and improvements in patients' functional status. Although MISS has continued to make significant progress clinically, consideration must also be given to its economic impact and the learning curve surgeons experience in adding these procedures to their armamentarium. This review examines current innovations in MISS, as well as the economic impact and future directions of the field.

Clival screw and plate fixation by the transoral approach for the craniovertebral junction: a CT-based feasibility study

PURPOSE

A clivus screw and plate was invented and proved to strengthen the stability of the craniovertebral junction (CVJ). However, it is unclear whether the clivus screw and plate could be placed onto the CVJ by transoral approach. Therefore, the present study aims to evaluate the feasibility of clivus screw and plate placement by transoral approach and investigate its relative anatomic parameters.

METHODS

A total of 80 normal adults (40 males/40 females) with an average age of 60.4 ± 11.6 years old were enrolled in this study. All parameters were measured in a supposed maximums mouth-opening status on computed tomography images, where the vertex of lower incisor was defined as Point A. The vertical intersection from Point A to extracranial clivus was defined as Point B, and its distance to the bottom of clivus was measured as B length. Point B was considered as ideal screw entry point. All the cases were divided into three types based on the location of Point B: above the top portion (Type 1), between the top and bottom portion (Type 2), and below the bottom portion (Type 3) of extracranial clivus. The B Length was defined as a minus value if the case belonged to Type 3. The anterior skull base angle, the angles between tangent of extracranial clivus and the lines from Point A to different parts of clivus, and distances between Point A and clivus and C1-3 vertebra were also measured.

RESULTS

One in eighty cases (1.2%) belonged to Type 1 with a B Length of 32.12 mm. Most cases (61.3%) were Type 2 with a B Length of 8.7 mm, while Type 3's was - 9.7 mm occupying for 37.5%. Significant statistic differences were found in anterior skull base angle between these three types (128.9°, 122.7° and 118.5° for Type 1, 2 and 3, respectively). The distances from Point A to the top and bottom portion of the clivus and the pharyngeal tubercle were 97.5, 96.0 and 96.8 mm, respectively. The angles between the tangent of the clivus and the lines from Point A to the above three structures were 75.7°, 92.3° and 84.0°, respectively. The distances from Point A to the middle point of anterior margin of C1 anterior tubercle, C2 vertebra and C3 vertebra were 79.1, 73.4 and 61.5 mm, respectively.

CONCLUSION

The clivus screw and plate placement could be accomplished with optimal screw angle by transoral approach in most of patients. Mandibular splitting would be needed in patients with greater anterior skull angle. These slides can be retrieved under Electronic Supplementary Material.

Step-up Establishment of Neurosurgical Laboratory Starting with Limited Resources-Tips and Tricks

BACKGROUND

Neurosurgical diseases have a devastating impact on society. It is estimated that approximately 14 million essential neurosurgical cases develop worldwide annually, of which more than 80% arise in low- and middle-income countries. Neurosurgical cadaveric dissection remains largely unexploited as a learning tool for the training of surgeons in developing countries, often because of the assumed high costs.

METHODS

The minimum requirements to establish a neurosurgical cadaver laboratory are the availability of minimally equipped environment to perform dissection, respecting safety requirements, fitting surgical instruments, anatomic samples, and materials to be used for preservation and preparation of anatomical specimens. Moving from these basic foundations, we established our Neurosurgical Dissection Laboratory at Fondazione Policlinico Universitario A. Gemelli IRCCS in Rome, Italy. The laboratory is located at the Institute of Public Health Section of Legal Medicine of University.

RESULTS

After reviewing relevant literature and discussing our experience, we provide advice for setting up a neurosurgical dissection cadaver laboratory with specific focus on suitable location identification, surgical equipment procurement, fresh cadaver and frozen specimen acquisition, and preparation and description of a step-up strategy to progressively enrich the laboratory.

CONCLUSIONS

Our study demonstrates the feasibility of establishing a neurosurgical cadaver dissection laboratory for training and research purposes even in presence of limited resources. The introduction of cost-effective guidelines and targeted funding could represent an added value to target the unmet neurosurgical disease need by promoting development of local neurosurgical expertise with the aim of providing health coverage for the treatment of common neurosurgical pathologies in developing countries.

Learning Curve in Surgical Treatment of Odontoid Fixation for a Series of Type II C2 Fractures

The craniovertebral junction (CVJ) is a complex anatomical area upon which most of the motion of the upper cervical spine depends [1]. Because of its unique range of motion, the CVJ is subject to several types of traumatic injury; it has been shown that odontoid fractures are the most common ones in the general population and are the most common isolated spinal fractures [2]. Accounting for up to 18% of all cervical fractures, odontoid fractures are the most common ones in elderly patients [3], in whom they account for up to 60% of spinal cord injuries [4].

Why the Craniovertebral Junction?

The craniovertebral junction (CVJ) has unique anatomical bone and neurovascular structure architecture. It not only separates the skull base from the subaxial cervical spine but also provides a special cranial flexion, extension and axial rotation pattern. Stability is provided by a complex combination of osseous and ligamentous supports, which allow a large degree of motion. Perfect knowledge of CVJ anatomy and physiology allows us to better understand instrumentation procedures of the occiput, atlas and axis, and the specific diseases that affect the region. Therefore, a review of the vascular, ligamentous and bony anatomy of the region, in relation to all possible surgical approaches to this anatomically unique segment of the cervical spine, appears to be absolutely mandatory in order to preview and to overcome possible anatomy-related complications of CVJ surgery; moreover, knowledge of the basic principles of instrumentation and of the kinematics of the region, since they interact with the anatomy, seems to be strategic in preoperative planning.Historically considered a no man's land, CVJ surgery, or the CVJ specialty, has recently attracted strong consideration as a symbol of challenging surgery as well as selective top-level qualifying surgery.Although many years have passed since the beginning of this pioneering surgery, managing lesions situated in the anterior aspect of the CVJ still remains a challenging neurosurgical problem. Many studies are available in the literature, aiming to examine the microsurgical anatomy of both the anterior and posterior extradural and intradural aspects of the CVJ, as well as the differences in all possible surgical exposures obtained by the 360° approach philosophy. In this paper the author provides a short but quite complete at-a-glance tour of personal experience and publications and the more recent literature available.