Approaches to the sellar and parasellar region: anatomic comparison of the microscope versus endoscope

Effect of the extent of posterior septectomy on surgical access during the endoscopic endonasal approach to the sella: A technical note

Background

Using the bi-nostril 4-hand technique during the endoscopic endonasal approach (EEA) facilitates bimanual microsurgical techniques yet requires resection of the posterior nasal septum. The surgical exposure and degree of maneuverability gained proportionate to the extent of posterior septectomy in the sagittal plane was previously quantified.

Research question

We aim to describe our technique of posterior septectomy, and the effect of its extent in the axial plane on surgical access, and instrument maneuverability.

Material and methods

After fracturing the posterosuperior nasal septum, we disarticulate the vomer from the sphenoid rostrum and remove its upper part. The sphenoid rostrum is excised next exposing the clival recess where a suction tip without a side channel is anchored, allowing the assisting surgeon to use an additional instrument in their dominant hand. The vomer is removed down to the level of the floor of the sphenoid sinus.

Results

A wide exposure is achieved in the coronal plane bilaterally at the level of the sphenoid rostrum allowing unobstructed instrument manipulation in the craniocaudal and cross-court trajectories. Furthermore, the floor of the sella is reached through a straight rather than angled trajectory facilitating surgical access, manipulation, and instrument maneuverability. For lateral lesions requiring contralateral access, the assisting surgeon can assist in dissection from the contralateral nostril without changing the position of the endoscope.

Discussion and conclusion

Removing the upper vomer improves surgical access, and instrument maneuverability. Simultaneous dissection from both nostrils might be attempted. Caudally extending the posterior septectomy during the EEA allows better exposure and improves surgical access in all planes.

Quantitative Anatomical Studies in Neurosurgery: A Systematic and Critical Review of Research Methods

BACKGROUND

The anatomy laboratory can provide the ideal setting for the preclinical phase of neurosurgical research. Our purpose is to comprehensively and critically review the preclinical anatomical quantification methods used in cranial neurosurgery.

METHODS

A systematic review was conducted following the PRISMA guidelines. The PubMed, Ovid MEDLINE, and Ovid EMBASE databases were searched, yielding 1667 papers. A statistical analysis was performed using R.

RESULTS

The included studies were published from 1996 to 2023. The risk of bias assessment indicated high-quality studies. Target exposure was the most studied feature (81.7%), mainly with area quantification (64.9%). The surgical corridor was quantified in 60.9% of studies, more commonly with the quantification of the angle of view (60%). Neuronavigation-based methods benefit from quantifying the surgical pyramid features that define a cranial neurosurgical approach and allowing post-dissection data analyses. Direct measurements might diminish the error that is inherent to navigation methods and are useful to collect a small amount of data.

CONCLUSION

Quantifying neurosurgical approaches in the anatomy laboratory provides an objective assessment of the surgical corridor and target exposure. There is currently limited comparability among quantitative neurosurgical anatomy studies; sharing common research methods will provide comparable data that might also be investigated with artificial intelligence methods.

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

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

Endonasal endoscopic versus microscopic transsphenoidal surgery in pituitary tumors among the young: A comparative study & meta-analysis

PURPOSE

The transsphenoidal approach presents unique challenges in young, with scanty literature. This study compares the outcome of pituitary tumors among young in our center between endoscopic(EES) and microscopic(MTS) transsphenoidal surgery, with a meta-analysis.

METHODS

Patients within 20 years were studied for their surgical approach to a favorable outcome of endocrine remission (ER) (functioning) or Gross/Near-Total resection (nonfunctioning), besides the need for retreatment. Relevant studies were pooled and analyzed according to PRISMA guidelines.

RESULTS

Out of 64 young patients with pituitary tumors, 48 underwent transsphenoidal surgery using MTS(33) or EES(15). Of these, 21, 14, 5, and 8 had Cushing's, somatotropinomas, prolactinomas, and non-secreting tumors, respectively. Mean symptom duration was 28months, with weight gain(50 %) and visual complaints(29 %) most prevalent. Hypogonadism(21 %) was the most frequent endocrinopathy. The mean tumor volume was 3.8 cm³. Over mean follow-up of 4.4years, favorable outcome was significantly higher after EES than MTS(78.6 % vs. 46.7 %)(odds ratio 4.18, p = 0.05). EES's better outcome was homogeneous across subgroups of age and tumor type, with no significant subgroup difference. Symptom duration was significantly higher among those who required retreatment(p = 0.05), while ER had a non-significant association with tumor volume(p = 0.07). Overall, 40 %, 27 %, 17 %, and 8% were on hydrocortisone, thyroxine, sex hormone, and desmopressin, respectively, at follow-up with no significant difference between EES and MTS. In pooled analysis of literature, both favorable outcome(74 % vs. 48 %,p = 0.02) and retreatment rate(8% vs. 37 %,p = 0.004) were significantly better with EES than MTS.

CONCLUSION

Among young patients with pituitary tumors, the favorable outcome and retreatment rates are better with endonasal endoscopy and associated with symptom duration and tumor volume.

Relationship between pneumatization of lateral recess in the sphenoid sinus and removal of cavernous sinus invasion in pituitary adenomas by endoscopic endonasal surgery

Background:

Endoscopic endonasal transsphenoidal surgery (EES) is the gold standard for pituitary adenoma (PA) resection. The sphenoid sinus (SS), a highly variable anatomic structure, is located in the center of the cranial base. It has previously been reported that poor pneumatization of the lateral recess of the SS (LRSS) increases the difficulty level of the surgery and the risk of neural and vascular injury. However, to date no studies have evaluated the association between LRSS volume and PAs removal rate by EES.

Methods:

The present study analyzed 23 consecutive patients with new-onset PAs categorized as Knosp Grades 3 and 4 who underwent EES. A retrospective radiographic analysis was conducted on patients undergoing magnetic resonance imaging and high-resolution computed tomography scans.

Results:

Among PA cases categorized as Knosp 3 and 4, no significant association was found between the whole tumor’s resection rate and LRSS volume (R = 0.08, P = 0.70). However, a significant association was found between cavernous sinus (CS) tumors’ removal rate and LRSS volume (R = 0.52, P = 0.011). The same results were achieved in PAs with a Knosp Grade 4, with a stronger correlation (R = 0.60, P = 0.014).

Conclusion:

The development of LRSS pneumatization affects the removal rate of CS tumors in PAs. Preoperative analysis of LRSS development should be considered when planning EES against PA with CS invasion.

Comparison of Techniques for Transsphenoidal Pituitary Surgery

Background

The aim of this study was to compare three different techniques for transsphenoidal pituitary surgery: (1) sublabial transseptal approach with microscopic resection, (2) transnasal transseptal approach with endoscopic resection, and (3) endoscopic approach with endoscopic resection.

Methods

We performed a retrospective review of 50 pituitary surgeries performed by the same neurosurgeon. Demographic, radiographic, and clinical data were collected.

Results

Fifteen patients underwent sublabial approach with microscopic tumor resection, 21 patients underwent the transnasal approach with endoscopic resection, and 14 patients underwent the completely endoscopic technique. There were a total of 20 complications in the sublabial group, 13 transnasal complications, and 6 endoscopic complications. Cerebrospinal fluid leak incidence was 53% in the sublabial approaches, 47% transnasal, and 28% in the endoscopic patients. Diabetes insipidus was encountered in 33% of sublabial approaches, 5% of transnasal approaches, and 7% of endoscopic approaches. Lumbar drains were required in 40% of sublabial approaches, 38% of transnasal approaches, and 7% of endoscopic approaches. Nasal packing was used in 100% of sublabial and transnasal approaches and 0% of endoscopic approaches. Mean recurrence rate and follow-up was sublabial in 6.6% (50 months), transnasal in 9.5% (11 months), and endoscopic in 0% (7 months). Average hospital stay for sublabial approaches, transnasal approaches, and endoscopic approaches was 8.3, 6.2, and 3.4 days, respectively (p < 0.05).

Conclusion

Transsphenoidal pituitary surgery has evolved over the past several decades, because advances in technology have been the catalyst for minimally invasive surgeries. Less invasive approaches, such as the transnasal approach with endoscopic resection of tumor and the completely endoscopic technique have less morbidity and a shorter hospital stay than traditional sublabial approaches. Continued follow-up is needed to confirm long-term benefits and similar recurrence rates.

Long-Term Endocrine Outcomes Following Endoscopic Endonasal Transsphenoidal Surgery for Acromegaly and Associated Prognostic Factors

BACKGROUND

Long-term remission rates from endoscopic transsphenoidal surgery for acromegaly and their relationship to prognostic indicators of disease aggressiveness are not well documented.

OBJECTIVE

To investigate long-term remission rates in patients with acromegaly after endoscopic transsphenoidal surgery, and correlate this with molecular and radiographic markers of disease aggressiveness.

METHODS

We identified all patients undergoing endoscopic transsphenoidal surgery for acromegaly from 2005 to 2013 at Cedars-Sinai Pituitary Center. Hormonal remission was established by normal insulin-like growth factor (IGF)-1, basal serum growth hormone <2.5 ng/mL, and growth hormone suppression to <1 ng/mL following oral glucose tolerance test. Oral glucose tolerance test was performed at 3 months after surgery, and then as indicated. IGF-1 was measured at 3 months and then at least annually. We evaluated tumor granularity, nuclear expression of p21, Ki67 index, and extent of cavernous sinus invasion, and correlated these with remission status.

RESULTS

Fifty-eight patients that underwent surgery had follow-up from 38 to 98 months (mean 64 ± 32.2 months). There were 21 microadenomas and 37 macroadenomas. Three months after surgery 40 of 58 patients (69%) were in biochemical remission. Four additional patients were in remission at 6 months after surgery, and 1 patient had recurrence within the first year after surgery. At last follow-up, 43 of 44 (74.1%) of patients remained in remission. Cavernous sinus invasion by tumor predicted failure to achieve remission.

CONCLUSIONS

Prognostic markers of disease aggressiveness other than cavernous sinus invasion did not correlate with surgical outcome. Long-term remission after surgery alone was achieved in 74% of patients, indicating long-term efficacy of endoscopic surgery.

Microsurgical resection of skull base meningioma-expanding the operative corridor

A better understanding of surgical anatomy, marked improvement in illumination devices, provision of improved hemostatic agents, greater availability of more precise surgical instruments, and better modalities for skull base reconstruction have led to an inevitable evolution of skull base neurosurgery. For the past few decades, many skull base neurosurgeons have worked relentlessly to improve the surgical approach and trajectory for the expansion of operative corridor. With the advent of newer techniques and their rapid adaptation, it is foundational, especially for young neurosurgeons, to understand the basics and nuances of modifications of traditional neurosurgical approaches. The goal of this topic review is to discuss the evolution of, concepts in, and technical nuances regarding the operative corridor expansion in the field of skull base surgery for intracranial meningioma as they pertain to achieving optimal functional outcome.

Quantification and comparison of neurosurgical approaches in the preclinical setting: literature review

There is a growing awareness of the need for evidence-based surgery and of the issues that are specific to research in surgery. Well-conducted anatomical studies can represent the first, preclinical step for evidence-based surgical innovation and evaluation. In the last two decades, various reports have quantified and compared neurosurgical approaches in the anatomy laboratory using different methods and technology. The aim of this study was to critically review these papers. A PubMed and Scopus search was performed to select articles that quantified and compared different neurosurgical approaches in the preclinical setting. The basic characteristics that anatomically define a surgical approach were defined. Each study was analyzed for measured features and quantification method and technique. Ninety-nine papers, published from 1990 to 2013, were included in this review. A heterogeneous use of terms to define the features of a surgical approach was evident. Different methods to study these features have been reported; they are generally based on quantification of distances, angles, and areas. Measuring tools have evolved from the simple ruler to frameless stereotactic devices. The reported methods have each specific advantages and limits; a common limitation is the lack of 3D visualization and surgical volume quantification. There is a need for a uniform nomenclature in anatomical studies. Frameless stereotactic devices provide a powerful tool for anatomical studies. Volume quantification and 3D visualization of the surgical approach is not provided with most available methods.

Evaluation of surgical freedom for microscopic and endoscopic transsphenoidal approaches to the sella

BACKGROUND

Microscopic and endoscopic transsphenoidal approaches to the sellar are well established. Surgical freedom is an important skull base principle that can be measured objectively and used to compare approaches.

OBJECTIVE

To compare the surgical freedom of 4 transsphenoidal approaches to the sella turcica to aid in surgical approach selection.

METHODS

Four transsphenoidal approaches to the sella were performed on 8 silicon-injected cadaveric heads. Surgical freedom was determined with stereotactic image guidance using previously established techniques. The results are presented as the area of surgical freedom and angular surgical freedom (angle of attack) in the axial and sagittal planes.

RESULTS

Mean total exposed area surgical freedom for the microscopic sublabial, endoscopic binostril, endoscopic uninostril, and microscopic endonasal approaches were 102 ± 13, 89 ± 6, 81 ± 4, and 69 ± 10 cm2, respectively. The endoscopic binostril approach had the greatest surgical freedom at the pituitary gland and ipsilateral and contralateral internal carotid arteries (25.7 ± 5.4, 28.0 ± 4.0, and 23.0 ± 3.0 cm2) compared with the microscopic sublabial (21.8 ± 3.5, 21.3 ± 2.4, and 19.5 ± 6.3 cm2), microscopic endonasal (14.2 ± 2.7, 14.1 ± 3.2, and 16.3 ± 4.0 cm2), and endoscopic uninostril (19.7 ± 4.8, 22.4 ± 2.3, and 19.5 ± 2.9 cm2) approaches. Axial angle of attack was greatest for the microscopic sublabial approach to the same targets (14.7 ± 1.3°, 11.0 ± 1.5°, and 11.8 ± 1.1°). For the sagittal angle of attack, the endoscopic binostril approach was superior for all 3 targets (16.6 ± 1.7°, 17.2 ± 0.70°, and 15.5 ± 1.2°).

CONCLUSION

Microscopic sublabial and endoscopic binostril approaches provided superior surgical freedom compared with the endonasal microscopic and uninostril endoscopic approaches. This work provides objective baseline values for the quantification and evaluation of future refinements in surgical technique or instrumentation.

Experimental study on restricting the robotic end-effector inside a lesion for safe telesurgery

INTRODUCTION

Using an endoscopic telesurgical robot system (ETSRS), the authors propose a strategy for improving the safety of telesurgery by restricting the movement of an end-effector within a lesion. The strategy is validated by phantom model experiments.

MATERIAL AND METHODS

The method focused on generation of force feedback and restriction of robotic end-effector movement of ETSRS based on a virtual wall. Collision detection and case classification procedures were used to determine whether the generation of force feedback or restricting the end-effector's movement was continued. The method was implemented in ETSRS and tested using a brain and tofu phantom.

RESULTS

Force feedback was well generated proportional to a linear combination of the insertion depth and the velocity of the end-effector of the ETSRS from the surface of the predefined virtual wall. The movement of the end-effector was well limited inside the virtual wall by the method. The virtual wall update was sufficiently fast to check the current surgical situation. The control rate of the entire system was >30 fps so that the method showed acceptable performance in phantom experiments.

CONCLUSION

The results show that the strategy allows for well controlled robotic end-effectors inside a predefined virtual wall by the robot itself and an operator through the signal and force feedback.

The transition from microscopic to endoscopic transsphenoidal surgery in high-caseload neurosurgical centers: the experience of Foch Hospital

OBJECTIVE

To report the experience of 1 hospital in the transition from the microscopic approach to the endoscopic endonasal approach for pituitary disease and skull base tumor surgery.

METHODS

From 2006 to August 2011, 1000 procedures to treat pituitary disease and skull base tumors were performed in our department by a single neurosurgeon using the endoscopic endonasal approach.

RESULTS

The endonasal endoscopic approach for pituitary adenoma surgery decreased nasal complications, increased patient comfort by avoiding postoperative nasal packing, provided a better view of the intrasellar and suprasellar areas, obtained the same endocrinologic results as the microscopic approach, provided better control of the invasion of the cavernous sinus, and allowed removal of tumors of the cavernous sinus in some cases.

CONCLUSIONS

It is important to separate the 2 approaches, the endoscopic endonasal transsellar approach and the endoscopic endonasal extended approach, and to avoid unnecessary extended approaches. The use of an endoscopic endonasal approach has added value for lesions localized between the tuberculum sellae and the odontoid. The added value of endoscopic endonasal approaches for lesions in front of the tuberculum sellae is less clear and must be evaluated in the future.

Advantages and limitations of endoscopic endonasal approaches to the skull base

BACKGROUND

The anatomy of the skull base is extremely complex with an abundance of critical neurovascular bundles and their corresponding foramina as well as the insertions and origins of multiple masticatory and craniocervical muscles. These anatomic intricacies increase the difficulty of surgery within this area.

METHODS

Advantages and disadvantages of endoscopic endonasal approaches (EEAs) based on the authors' sequential learning and experience are described.

RESULTS

EEAs offer the advantages of using preexistent air spaces that enable accessing various areas of the skull base, while avoiding external incisions or scars and obviating the need for the translocation of the maxillofacial skeleton. In addition, EEAs are well suited to preserve neurologic, visual, and masticatory functions as well as cosmesis. However, the sinonasal corridor must be expanded and optimized to access the skull base adequately, facilitate the reconstruction of the surgical defect, avoid sinonasal complications, and minimize sequelae. Important considerations can limit or indicate the approach, such as the nature of the pathology, including location, diagnosis, and vascularity; patient characteristics, including age and medical comorbidities; surgeon attributes, including training, experience, and expertise; the resultant need to reconstruct large skull base defects and feasible alternatives to do so; and institutional resources, including adjunctive services, an intensive care unit, and operating room equipment.

CONCLUSIONS

EEAs are important techniques in contemporary skull base surgery. Understanding the indications for and limitations of these approaches help to maximize outcomes.

Endoscopic endonasal surgery for pituitary adenomas

BACKGROUND

Pituitary surgery is a continuous evolving specialty of the neurosurgeons' armamentarium, which requires precise anatomic knowledge, technical skills, and integrated culture of the pituitary pathophysiology. Actually it cannot be considered only from a technical standpoint, but rather a procedure resulting from the close cooperation among different specialists (e.g., ophthalmologists, neuroradiologists, endocrinologists, neurosurgeons, otorhinolaryngologists, anesthesiologists, neurophysiologists, pathologists, instrument manufacturers).

METHODS

The "pure" endoscopic endonsal surgery is a procedure performed through the nose, with the endoscope alone throughout the whole approach and without any transsphenoidal retractor. The procedure consists of three main aspects: exposure of the lesion, removal of the relevant pathology, and reconstruction, going through three different steps, the nasal, the sphenoid, and the sellar phases.

CONCLUSIONS

The endoscopic approach offers some advantages due to the endoscope itself: a superior close-up view of the relevant anatomy and an enlarged working angle are provided with an increased panoramic vision inside the surgical area. Concerning results in terms of mass removal, relief of clinical symptoms, cure of the underlying disease, and complication rate, these are, at least, similar to those reported in the major microsurgical series, but patient compliance is by far better. Besides the advantages to the patients, the surgeons-because of the wider and closer view of the surgical target area and the increase of the scientific activity as from the peer-reviewed literature on the topic in the past 10 years, the smoothing of interdisciplinary cooperation-, and the institutions (shorter postoperative hospital stay and increase of the case load)- the adoption of endoscopy in transsphenoidal surgery has gained a strong foothold.

Pro: endoscopic endonasal transsphenoidal pituitary surgery is superior to microscope-based transsphenoidal surgery

The introduction of the endoscope to transsphenoidal pituitary surgery is relatively new, but represents a major advancement in the field. The use of the endoscope to visualize the sella via a direct endonasal approach offers the surgeon dramatically better visualization as well as improved range of motion compared to the operating microscope. Growing evidence confirms that these improvements directly translate into better surgical resections and outcomes. Further, patient comfort and satisfaction are higher with the endonasal method compared with other transsphenoidal approaches, and it is a cost effective technology. This position paper will outline the reasons that endoscopic endonasal transsphenoidal surgery is the preferred method for pituitary surgery, and why it will likely be adopted as the standard technique for transsphenoidal surgery worldwide.

Construction and verification of a safety region for brain tumor removal with a telesurgical robot system

BACKGROUND

The authors propose and verify a method for the construction of a safety region for minimally invasive brain tumor removal. The safety region is constructed to avoid damaging normal tissues through the movement of a robotic instrument during brain tumor surgery using a telesurgical robotic system and a small port.

MATERIAL AND METHODS

3 D boundaries of a tumor and a port were generated as a critical wall to avoid invading normal tissues through an image processing algorithm with consideration of a safe margin. Then, fast collision detection between the boundary and the robotic instrument was continuously performed to monitor the movement of the robotic instrument.

RESULTS

An experiment was conducted using the prototype of a telesurgical robot system and a hemispherical phantom. A 3 D boundary was generated from the CT images of the phantom with a safe margin of 2.76 mm. The robotic instrument did not penetrate the boundary.

CONCLUSION

The experimental result shows that our method can contribute toward safe brain tumor removal with robotic surgery.

Quantitative analysis of progressive removal of nasal structures during endoscopic suprasellar approach

OBJECTIVES/HYPOTHESIS

Following recent studies measuring working area and surgical freedom of transcranial approaches, we aimed to quantify the gain achieved with progressive removal of nasal structures during the endoscopic endonasal suprasellar approach.

STUDY DESIGN

Human cadaveric anatomic study.

METHODS

The width of the endoscopic endonasal corridor to the suprasellar area was obtained and measured in five cadaver heads using a computerized tracking system with six steps: 1) standard approach with monolateral lateralization of middle turbinate; 2) standard bilateral lateralization of the middle turbinates; 3) monolateral middle turbinectomy; 4) bilateral middle turbinectomy; 5) monolateral ethmoidectomy; 6) bilateral ethmoidectomy.

RESULTS

The progressive removal of nasal structures offers a nonlinear increasing of the working area during the first steps of the procedure. The maximum advantage is offered by bilateral lateralization of the middle turbinates (102.7% increase in exposure), whereas a moderate increase is observed with each following step. Surgical freedom mainly increased during the first part of the approach, that is, with a monolateral right middle turbinectomy (17.9% raise of maneuverability), whereas additional steps did not increase surgical freedom enough to justify an aggressive nasal disruption.

CONCLUSIONS

Monolateral turbinectomy on the side of endoscope docking represents the best solution, optimizing working area and surgical freedom (offering increases of 116.9% and 17.9%, respectively). Bilateral turbinectomy, together with a monolateral anterior and posterior ethmoidectomy, can be reserved for selected cases (increases of 148.5% and 24.7%, respectively). Bilateral ethmoidectomy does not significantly improve surgical freedom (0.81%).

LEVEL OF EVIDENCE

N/A. Laryngoscope 124:2231-2237, 2014.

Single-surgeon fully endoscopic endonasal transsphenoidal surgery: outcomes in three-hundred consecutive cases

The objective of this study was to evaluate outcomes of endoscopic transsphenoidal surgery using a single-surgeon technique as an alternative to the more commonly employed two-surgeon, three-hand method. Three hundred consecutive endoscopic transsphenoidal procedures performed over a 5 year period from 2006 to 2011 were reviewed. All procedures were performed via a binasal approach utilizing a single surgeon two handed technique with a pneumatic endoscope holder. Expanded enodnansal cases were excluded. Surgical technique, biochemical and surgical outcomes, and complications were analyzed. 276 patients underwent 300 consecutive surgeries with a mean follow-up period of 37 ± 22 months. Non-functioning pituitary adenoma (NFPA) was the most common pathology (n = 152), followed by growth hormone secreting tumors (n = 41) and Rathke's cleft cysts (n = 30). Initial gross total cyst drainage based on radiologic criteria was obtained in 28 cases of Rathke's cleft cyst, with 5 recurrences. For NFPA and other pathologies (n = 173) gross total resection was obtained in 137 cases, with a 92% concordance rate between observed and expected extent of resection. For functional adenoma, remission rates were 30/41 (73%) for GH-secreting, 12/12 (100%) for ACTH-secreting, and 8/17 (47%) for prolactin-secreting tumors. Post-operative complications included transient (11%) and permanent (1.4%) diabetes insipidus, hyponatremia (13%), and new anterior pituitary hormonal deficits (1.4%). CSF leak occurred in 42 cases (15%), and four patients required surgical repair. Two carotid artery injuries occurred, both early in the series. Epistaxis and other rhinological complications were noted in 10% of patients, most of which were minor and diminished as surgical experience increased. Fully endoscopic single surgeon transsphenoidal surgery utilizing a binasal approach and a pneumatic endoscope holder yields outcomes comparable to those reported with a two-surgeon method. Endoscopic outcomes appear to be better than those reported in microscope-based series, regardless of a one or two surgeon technique.

Pituitary macroadenoma: a case report and review

Pituitary adenomas are the most common tumours of the sellar region. They generally have a slow but severe impact on vision due to compression of the optic nerves, optic chiasm and cavernous sinus. This case report reviews the clinical presentation, management and treatment of the major classifications of pituitary adenoma. As Australian optometrists perform over 300,000 visual field assessments per year, it is vital they are aware of this important cause of visual field loss.

Endoscopic, endonasal, trans-sphenoidal hypophysectomy: retrospective analysis of 171 procedures

INTRODUCTION

Endoscopic, transnasal management of pituitary gland neoplasms is a widely accepted alternative to the traditional microscopic approach. This study aimed to determine outcomes and complication rates for the largest UK series of endoscopic, trans-sphenoidal hypophysectomies reported to date.

METHODS

We performed a retrospective analysis of 136 primary resections and 35 revision cases performed at a tertiary referral centre.

RESULTS AND ANALYSIS

Total tumour resection was confirmed in over 85 per cent of primary and revision cases, with biochemical remission in 60 per cent. The incidence of complications such as epistaxis, sphenoid sinus problems, endocrine insufficiency, visual disturbance, post-operative haemorrhage, cranial nerve injury and mortality was significantly lower, compared with similar series using the microscopic approach.

CONCLUSION

Despite its steep 'learning curve', our series demonstrates that the endoscopic approach not only allows superior anatomical visualisation and therefore facilitates full oncological resection of tumours, but also reduces the incidence of peri-operative complications.

Value of anatomical landmarks in single-nostril endonasal transnasal-sphenoidal surgery

The sphenoid sinus occupies a central location in transsphenoidal surgery (TSS). It is important to identify relevant anatomical landmarks to enter the sphenoid sinus and sellar region properly. The aim of this study was to identify anatomical landmarks and their value in single-nostril endonasal TSS. A retrospective study was performed to review 148 cases of single-nostril endonasal TSS for pituitary lesions. The structure of the nasal cavities and sphenoid sinus, the position of apertures of the sphenoid sinus and relevant arteries and the morphological characteristics of the anterior wall of the sphenoid sinus and sellar floor were observed and recorded. The important anatomical landmarks included the mucosal aperture of the sphenoid sinus, a blunt longitudinal prominence on the posterior nasal septum, the osseocartilaginous junction of the nasal septum, the 'bow sign' of the anterior wall of the sphenoid sinus, the osseous aperture and its relationship with the nutrient arteries, the bulge of the sellar floor and the carotid protuberance. These landmarks outlined a clear route to the sella turcica with an optimal view and lesser tissue damage. Although morphological variation may exist, the position of these landmarks was generally consistent. Locating the sphenoid sinus aperture is the gold standard to direct the surgical route of TSS. The 'bow sign' and the sellar bulge are critical landmarks for accurate entry into the sphenoid sinus and sella fossa, respectively.

Indications and limitations of endoscopic skull base surgery

A wealth of critical neurovascular structures within a relatively small surface area adds to the already intricate nature of skull base surgery. Surgical approaches to the area are difficult and often associated with significant morbidity and mortality. During the past two decades, endoscopic endonasal approaches (EEAs) have evolved to access the ventral skull base for the resection of tumors (benign and malignant), the decompression of neural structures including the cervicomedullary junction (pannus from rheumatoid arthritis or congenital anomalies, such as platybasia) and the reconstruction of skull base defects (cerebrospinal leaks, meningoencephalocele). These minimal access approaches obviate the need for external incisions, translocation of maxillofacial bones and retraction of the brain. Furthermore, EEAs yield improved visualization, which may reduce complications, and improve quality of life outcomes. Anatomical difficulties (e.g., vascular encasement or extension beyond the plane of a major vessel or cranial nerve), various special conditions (e.g., pediatric patients and vascular tumor) and limitation of institutional resources and technical difficulties may limit the use of EEAs. Thus, one should understand the indications and limitations of EEAs to optimize patient selection, which, in turn, may lead to superior surgical outcomes and reduced morbidity.

Recent advances in pituitary tumor management

PURPOSE OF REVIEW

Advances in the neurosurgical management of pituitary tumors have included the refinement of surgical access and significant progress in navigation technology to help further reduce morbidity and improve outcome. Similarly, stereotactic radiosurgery has evolved to become an integral part in pituitary tumors not amenable to medical or surgical treatment.

RECENT FINDINGS

The evolution of minimally invasive surgery has evolved toward endoscopic versus microscopic trans-sphenoidal approaches for pituitary tumors. Debate exists regarding each approach, with advocates for both championing their cause. Stereotactic and fractional radiosurgery have been shown to be a safe and effective means of controlling tumor growth and ensuring hormonal stabilization, with longer-term data available for GammaKnife compared with CyberKnife.

SUMMARY

The advances in trans-sphenoidal surgical approaches, navigation technological improvements and the current results of stereotactic radiosurgery are discussed.

Comparison of the exposure obtained by endoscope and microscope in the extended trans-sphenoidal approach

OBJECTIVE

Trans-sphenoidal surgery is often combined with other approaches for the treatment of middle cranial base tumors. By combining a maxillotomy with trans-sphenoidal approach, significantly wider exposure to these regions is gained. However, endoscope-assisted techniques have also been used for sellar and parasellar and upper clival regions.

METHODS

An extended trans-sphenoidal approach was performed on 10 cadaver heads using the operating microscope and was repeated with a 0-degree endoscope. The mean horizontal and vertical distances were measured and pictured for each technique, and both distances were compared using a parametric paired Student's t-test.

RESULTS

The mean horizontal distances in the 10 specimens were 19.5 +/- 1.8 mm by microscope and 27.5 +/- 2.2 mm by endoscope, and the mean vertical distances were 25.8 +/- 1.9 mm by the microscope and 34.5 +/- 3.5 mm by the endoscope.

CONCLUSION

The aim of this study was to quantify the amount of exposure obtained with an extended trans-sphenoidal approach and to compare both endoscopic and microscopic techniques. Using the endoscope in conjunction with the operating microscope may provide additional exposure and better access in skull base surgery.

Intraoperative computed tomography registration and electromagnetic neuronavigation for transsphenoidal pituitary surgery: accuracy and time effectiveness

Object

The authors assessed the feasibility, anatomical accuracy, and cost effectiveness of frameless electromagnetic (EM) neuronavigation in conjunction with portable intraoperative CT (iCT) registration for transsphenoidal adenomectomy (TSA).

Methods

A prospective database was established for data obtained in 208 consecutive patients who underwent TSA in which the iCT/EM navigation technique was used. Data were compared with those acquired in a retrospective cohort of 65 consecutive patients in whom fluoroscope-assisted TSA had been performed by the same surgeon. All patients in both groups underwent transnasal removal of pituitary adenomas or neuroepithelial cysts, using identical surgical techniques with an operating microscope. In the iCT/EM technique–treated cases, a portable iCT scan was obtained immediately prior to surgery for registration to the EM navigation system, which did not require rigid head fixation. Preexisting (nonnavigation protocol) MR imaging studies were fused with the iCT scans to enable 3D navigation based on MR imaging data. The accuracy of the navigation system was determined in the first 50 iCT/EM cases by visual concordance of the navigation probe location to 5 preselected bony landmarks. For all patients in both cohorts, total operating room time, incision-to-closure time, and relative costs of imaging and surgical procedures were determined from hospital records.

Results

In every case, iCT registration was successful and preoperative MR images were fused to iCT scans without affecting navigation accuracy. There was 100% concordance between probe tip location and predetermined bony loci in the first 50 cases involving the iCT/EM technique. Total operating room time was significantly less in the iCT/EM cases (mean 108.9 ± 24.3 minutes [208 patients]) compared with the fluoroscopy group (mean 121.1 ± 30.7 minutes [65 patients]; p < 0.001). Similarly, incision-to-closure time was significantly less for the iCT/EM cases (mean 61.3 ± 18.2 minutes) than for the fluoroscopy cases (mean 71.75 ± 19.0 minutes; p < 0.001). Relative overall costs for iCT/EM technique and intraoperative C-arm fluoroscopy were comparable; increased costs for navigation equipment were offset by savings in operating room costs for shorter procedures.

Conclusions

The use of iCT/MR imaging–guided neuronavigation for transsphenoidal surgery is a time-effective, cost-efficient, safe, and technically beneficial technique.

Nasal, sellar, and sphenoid sinus measurements in relation to pituitary surgery

A study of 24 adult Caucasian cadavers was undertaken to assess and document the anatomical measurements within the nasal cavity and sphenoid sinus as routes of instrumentation utilized in sublabial transsphenoidal and endonasal endoscopic approaches. Five measurements were performed. The mean thickness of the anterior sellar wall was 0.8 +/- 0.3 mm for both the sellar and presellar types of sinuses, respectively. Also, the mean thickness of the bony floor of the sellar type of sinus was 0.9 +/- 0.4 mm. In addition, the mean depth of the sphenoid sinus was 13.6 +/- 5.1 mm for the sellar type and 13.2 +/- 3.9 mm for the presellar type of sinus. Furthermore, the mean distance between the suspinale (inferior-posterior edge of the anterior nasal spine) and the anterior sphenoid wall was 62.3 +/- 4.6 mm for the sellar type of sinus (P < 0.05) and 60.6 +/- 2.9 mm for the presellar type of sinus, while the distance between the subspinale and the anterior sellar wall had a mean value of 75.9 +/- 6.3 mm for the sellar type of sinus (P < 0.05) and 73.8 +/- 4.2 mm for the presellar type of sinus, with the distance of the sellar type sinus being greater for male specimens. Sphenoid sinus pneumatization was of a conchal type in 4%, presellar type in 28%, and sellar type in 68% of subjects examined. The results of the current study expand upon current anatomical knowledge and may be beneficial in the future refinement of surgical instrument design.

Microscopic and endoscopic extracranial approaches to the cavernous sinus: anatomic study

OBJECTIVE

In the past 2 decades, various extracranial approaches to the cavernous sinus (CS), using either microscopic or endoscopic techniques, have been described. The aim of this study was to describe the distinctive anatomic features of these approaches and compare their efficacy in exposing the sella and parasellar areas.

METHODS

Ten adult cadaver heads with red latex injected in the arterial system were used. Five different approaches were performed: 1) endonasal microscopic transsphenoidal approach; 2) sublabial microscopic transsphenoidal approach, including its variation described by Fraioli et al. ; 3) transmaxillary microscopic approach; 4) paraseptal endoscopic transsphenoidal approach; and 5) transethmoid-pterygoid-sphenoidal endoscopic approach. The CS exposition was evaluated for each approach and a grading system, which considers surgical maneuverability as well as visualization, was used.

RESULTS

The medial CS compartment is well exposed with all endoscopic and microscopic transsphenoidal approaches, but it is insufficiently exposed with the transmaxillary approach. The variation to the sublabial microscopic approach suggested by Fraioli et al. allows its widest microsurgical exposure. The lateral compartment is well visualized with the transmaxillary microscopic and the endoscopic approaches. The major anatomic structures that can limit exposure of the CS lateral compartment are the posterior ethmoid and medial pterygoid process.

CONCLUSION

The sublabial transsphenoidal microscopic approach, with its variations, allows the most versatile extracranial microscopic exposure of the sella and CS. The paraseptal, binostril endoscopic approach allows a very good exposure of the CS; the transethmoid-pterygoid-sphenoidal endoscopic approach achieves the best maneuverability in the lateral compartment of the CS.

EXPANDED ENDOSCOPIC ENDONASAL APPROACH FOR ANTERIOR CRANIAL BASE AND SUPRASELLAR LESIONS

OBJECTIVE

The traditional boundaries of the transsphenoidal approach can be expanded to include the region from the cribriform plate of the anterior cranial fossa to the foramen magnum in the anteroposterior plane. The introduction of endoscopy to transsphenoidal surgery, with its improved illumination and wider field of view, has added significant further potential for the resection of a variety of cranial base lesions. We review our experience with the expanded endoscopic endonasal approach in a series of 22 patients with anterior cranial base and supradiaphragmatic lesions.

METHODS

From June 2005 to June 2007, the expanded endoscopic endonasal approach was used in 22 patients with the following pathologies: 6 craniopharyngiomas; 4 esthesioneuroblastomas; 3 giant pituitary macroadenomas; 2 suprasellar Rathke's pouch cysts; 2 angiofibromas; and 1 each of suprasellar meningioma, germinoma, ethmoidal carcinoma, adenoid cystic carcinoma, and large suprasellar arachnoid cyst. This study specifically focused on the surgical indications and approaches to these lesions and the surgical results, complications, and limitations associated with this technique.

RESULTS

Gross total tumor removal, as assessed by postoperative magnetic resonance imaging, was possible in the majority of patients (73%), with the exception of the craniopharyngioma group, in which only 1 lesion was completely removed. There were no permanent neurological complications except for increased visual disturbance in 1 patient. Other complications included cerebrospinal fluid fistulae in 4 patients (18%) and meningitis in 1 patient (5%). There was no operative mortality. Large lesions, significant lateral extension, encasement of neurovascular structures, and brain invasion in malignant lesions are considered some of the contraindications for this technique.

CONCLUSION

The expanded endoscopic endonasal approach is a promising minimally invasive alternative to open transcranial approaches for selective lesions of the midline anterior cranial base. The avoidance of craniotomy and brain retraction and reduced neurovascular manipulation with less morbidity are potential advantages. Major complications have been few, but there are also limitations with this technique. This approach should be included in the armamentarium of cranial base surgeons and considered as an option in the management of selected patients with these complex pathologies.

Combined endoscopic and microscopic management of pediatric pituitary region tumors through one nostril: technical note with case illustrations

OBJECTIVE

Sellar and parasellar lesions in the pediatric population have traditionally been approached through either a transsphenoidal hypophysectomy or craniotomy or a combination of the two, with the surgical approach being dictated by the anatomical location and extent of the pathology. The introduction and evolution of the endonasal endoscopic technique has provided a minimally invasive method alone or in combination with the operative microscope for removal of these lesions in the pediatric population. The authors have implemented in their practice the use of endonasal endoscopic-assisted microsurgery in the pediatric population harboring sellar and/or lesions extending to the suprasellar space and report our experience in nine patients.

MATERIALS AND METHODS

Five craniopharyngiomas, one Rathke's cleft cyst, and two pituitary tumors were treated via endonasal endoscopic-assisted microsurgery. Histopathologic examination revealed lymphocytic hypophysitis in one patient with an enhancing lesion in the pituitary stalk. The approach utilized by the authors is performed through one nostril without any resection of the nasal turbinates or nasal septum. The middle turbinate is displaced laterally, while the nasal septum is moved medially.

CONCLUSION

Gross total, near-total, and subtotal resections and a diagnostic biopsy were obtained in six, one, one, and one patients, respectively. The authors were able to safely perform this procedure in nine pediatric patients, and the lack of turbinate or septum resection minimized postoperative discomfort.

Transsphenoidal approaches to the pituitary: a progression in experience in a single centre

BACKGROUND

Evolving of a single centre by means of different transsphenoidal approaches during the survey of methodological advances in pituitary surgery is presented.

MATERIALS AND METHODS

Ninety-three consecutive patients with pituitary adenomas underwent transphenoidal pituitary operations at Gulhane Military Medical Academy from January 1996 to October 2007. Retrospective chart-based analysis of the surgical methods of transsphenoidal pituitary adenoma operations were done. Surgical methods were described. Outcomes and complications were presented. Attention is focused on the methodology of different surgical techniques of pituitary surgery.

FINDINGS

During the evaluation period, 12 Sublabial approaches (1996-1998), 13 transseptal transsphenoidal approaches (1999-2000), 15 endonasal transsphenoidal approaches (2000-2004), 25 endoscopy assisted endonasal approaches (2002-2006) and 28 pure endoscopic endonasal approaches (2006-2007) were performed.

CONCLUSIONS

Technologic advancements in endoscopy and gaining experience in pituitary surgery drives neurosurgeons toward less invasive approaches.

Rhinologic Outcomes of Concurrent Operation for Pituitary Adenoma and Chronic Rhinosinusitis: An Early Experience

Background

The transsphenoidal approach (TSA) is the procedure of choice for the vast majority of pituitary neoplasms. Sinusitis is considered a contraindication to TSA because of possible transcranial spread of infection. This study was performed to determine if TSA for pituitary tumors could be extended to patients with pituitary adenoma and chronic rhinosinusitis (CRS).

Methods

Medical records, including rhinologic outcomes, were retrospectively assessed in 11 consecutive patients who underwent concurrent TSA and endoscopic sinus surgery (ESS) because of pituitary adenoma and CRS between May 2004 and October 2007.

Results

The 11 patients consisted of 5 men and 6 women, with a mean age of 55 years (range, 31–69 years) and average follow-up of 24.4 months (range, 6–44 months). Preoperatively, all patients had symptoms of CRS, but none had acute exacerbation of rhinosinusitis. All patients had CRS and two had nasal polyps. TSA was via the transcolumellar transseptal approach in seven patients and the transnasal approach in four patients. No postoperative complications due to ESS were observed. Two patients, including one with sphenoid aspergillosis, had preoperative unilateral sphenoid sinusitis, which was managed by ESS on the involved side, with TSA performed concurrently through the contralateral healthy sphenoid sinus. There was one case of postoperative sphenoid sinusitis and one case of septal perforation due to TSA. There were no postoperative intracranial complications, including meningitis and brain abscess.

Conclusion

Concurrent TSA and ESS can be performed in selected patients with CRS and pituitary adenoma. Future studies should involve more patients and longer follow-ups.

A Short Trapezoidal Speculum for Suprasellar and Infrasellar Exposure in Endonasal Transsphenoidal Surgery

Objective:

A key limitation of the transsphenoidal approach for suprasellar and infrasellar lesions is restricted exposure. Microscope and endoscope-assisted procedures have traditionally used an oval-shaped speculum, the distal end of which restricts superior and inferior visualization. To improve visualization and use of the endoscope, shorter specula, with a trapezoidal distal end, were designed.

Methods:

The new specula have a working length of 60 mm. The proximal 20-mm segment is oval-shaped to conform to the nostril; the middle 20-mm segment has vertically oriented blades; and the distal 20-mm segment transitions to a trapezoidal orientation, with the distal blades angled 15 degrees upward and outward on the suprasellar speculum, or 15 degrees downward and outward on the infrasellar speculum. Both specula have a 5-degree distal outward flare. The upward-angled trapezoidal 60-mm speculum was compared with 70- and 80-mm oval specula in a transsphenoidal clay model. A pen light was projected from the nasal speculum end to a target 100 mm away using a blade opening width of 16 mm. Line drawings were made to quantify the impact of speculum length on the horizontal angle of exposure. The clinical utility of the trapezoidal specula was also assessed.

Results:

In the model, the 60-mm upward-angled trapezoidal speculum yielded a surface area illumination of 759 mm2, as compared with 579 and 432 mm2 with the 70-and 80-mm oval specula, an increase in exposure of 31 and 76%, respectively. In the line drawings, the 60-mm speculum provided a horizontal angle of exposure of 30 degrees, as compared with 26 and 23 degrees for the 70- and 80-mm specula, an increase of 17 and 33%, respectively. In patients, provided sufficient mucosa and bone are removed from the posterior nasal cavity, the trapezoidal specula provide an expanded working volume that facilitates endoscopy.

Conclusion:

Short upward- or downward-angled trapezoidal endonasal specula increase parasellar surface area exposure and the horizontal angle of exposure. Initial clinical experience suggests that reducing the speculum length and eliminating the distal curved blades result in greater instrument maneuverability and enhanced visibility for removing parasellar tumors.

Endoscopic endonasal approach to the ethmoidal planum: anatomic study

The endoscopic endonasal technique is currently used by otolaryngologists for the management of different extradural lesions located below the ethmoidal planum. The cooperation between ENTs and neurosurgeons has recently pushed the use of such approach also in the removal of some intradural lesions, which has promoted the interest for an anatomic study to identify the anatomical landmarks and the dangerous points during the endoscopic approach to this area. In six fresh cadaver heads, unilateral and bilateral measurements between the main landmarks of the approach were performed by means of an endoscopic endonasal approach. A wide exposure of the midline anterior skull base was realized. The maximum of lateral extension was obtained between the two medial orbital walls, at the middle of the cribriform plate (mean distance 25,33 mm), while the mean distance between the anterior and posterior ethmoidal arteries at the level of the lamina papyracea was 16 mm. The endoscopic endonasal route can be considered a minimally invasive technique to approach the ethmoidal planum. It requires adequate anatomical knowledge and endoscopic skill for its realization. Due to the wide window realizable through this corridor, it could be considered in selected cases for the removal of intradural lesions such as meningiomas or estesioneuroblastomas.

Endonasal microscopic removal of clival chordomas

INTRODUCTION

Clival chordomas have traditionally been removed using a variety of anterior and lateral skull base approaches. Herein, we evaluate the outcomes of patients who underwent an extended endonasal transsphenoidal removal of a clival chordoma.

METHOD

All consecutive patients with a clival chordoma treated using an endonasal microscope approach were identified. In 8 cases, frameless surgical navigation was used, and in 4 cases, endoscopic assistance was used. Patients treated with prior radiotherapy were excluded.

RESULT

Over 5 years, 18 procedures were performed on 14 patients (7 females; mean age, 47 years). Patients were followed from 3 to 58 months (median, 20 months). Mean tumor diameter was 32 +/- 17 mm; 7 (50%) patients had intradural extension. Postoperative MRIs after the initial operation showed gross total, near-total (>90%), and subtotal resection in 43%, 43%, and 14% of patients, respectively. Use of the endoscope was associated with gross total or near-total tumor removal in 4 of 4 cases. Tumor regrowth occurred in 2 (14%) cases 10 and 12 months after the initial surgery and before radiotherapy. Two patients had multiple operations, in one as a planned staged operation, and in the other, 3 additional debulkings were performed despite an initial gross total removal. Nine patients, all with CS invasion, had subsequent stereotactic radiation. Of 10 patients with cranial neuropathy, 80% improved or resolved including 75% and 67% of sixth and fifth CN palsies, respectively. Complications included one each of adrenal insufficiency and chemical meningitis. There were no CSF leaks or new neurological deficits.

CONCLUSION

In this small series with relatively short follow-up, endonasal microscopic removal of clival chordomas proved safe and elfective with gross total or near-total removal in 86% of patients and improvement of cranial neuropathy in 80% of patients. Endoscopy for aiding tumor removal and assessing completeness of resection, as well as surgical navigation, are recommended for all cases.

Endoscopic pituitary surgery

Pituitary surgery is a continuous evolving speciality of the neurosurgeons' armamentarium, which requires precise anatomical knowledge, technical skills and integrated appreciation of the pituitary pathophysiology. What we consider "pure" endoscopic transsphenoidal surgery is a procedure performed through the nose and the sphenoid bone, with the endoscope alone throughout the whole approach to visualize the surgical target area and without the use of any transsphenoidal retractor. It offers some advantages due to the endoscope itself: a superior close-up view of the relevant anatomy and an enlarged working angle are provided with an increased panoramic vision inside the surgical area. Concerning results in terms of mass removal, relief of clinical symptoms, cure of the underlying disease and complication rate, they are, at least, similar to those reported in the major microsurgical series, but patient compliance is by far better. Furthermore transsphenoidal endoscopy brings advantages to the patient (less nasal traumatism, no nasal packing, less post-op pain and usually quick recovery), to the surgeon (wider and closer view of the surgical target area, increase of the scientific activity as from the peer-reviewed literature on the topic in the last 10 years, smoothing of interdisciplinary cooperation), to the institution (shorter post-op hospital stay, increase of the case load). Besides, further progress and technological advance are expected from the close cooperation between different technologies and industries. Continuing works in such field of "minimalism" will offer further possibilities to provide the surgeon with even more effectiveness and safety, and, on the other hand, the patient with improvement of results.

Endoscope or microscope?

Object.

The authors compare the views afforded by the operating microscope and the endoscope in the direct endonasal extended transsphenoidal approach to the sellar, suprasellar, and parasellar regions.

Methods.

Five formalin-fixed, silicone-injected adult cadaveric heads were studied. A direct endonasal transsphenoidal approach was performed via the right nostril, pushing aside the nasal septum. The approach was performed with the microscope first, then with the endoscope. For each step (sellar, suprasellar, and clival), the exposure afforded by direct microscopic view was measured and then compared with that obtained using the endoscope. The direct endonasal approach provides a slightly off-midline view. Although the microscope provides an adequate view of the midline structures and part of the contralateral parasellar areas, the addition of the endoscope allows for a more panoramic view and permits widening of the approach in all directions.

Conclusions.

An adequate exposure of the sellar, suprasellar, and infrasellar/upper clival regions can be achieved via a simple, direct endonasal approach. From a direct endonasal route, there is a preferential visualization of the structures contralateral to the approach. The endoscope affords a more panoramic view that extends the area covered by the operating microscope.

Back to the Egyptians: neurosurgery via the nose. A five-thousand year history and the recent contribution of the endoscope

The possibility of removing the brain through the nose without disfiguring the face was already known to the ancient Egyptians, who were experts in using this approach in the mummification process. A similar route through the nose and the sphenoid bone has been developed in the last century as a surgical procedure for the treatment of tumors of the pituitary region, which makes the more invasive craniotomy unnecessary in most cases. This has resulted in a significant decrease of the overall mortality and morbidity rates and has led to the great popularity of such minimally invasive surgery both for patients and doctors. The recent advent of the endoscope in this specific field and the development of further possibilities and instrumentation has contributed to a new renaissance of this old treatment modality.

Endoscopie et traitement chirurgical des macroadénomes hypophysaires endo- et suprasellaires invasifs

BACKGROUND AND PURPOSE

Surgery of invasive endo- and suprasellar pituitary macroadenomas remains difficult. The records of 13 consecutive patients who underwent transsphenoidal surgery were analyzed in order to evaluate advantages and limitations of endoscopy for surgery of invasive pituitary macroadenomas.

METHODS

A transseptal transsphenoidal intersepto-columellar approach was performed with a nasal 0-degree endoscope. Removal of the macroadenoma was performed under the control of a microscope. When the tumor seemed to be completely removed with microscope, a rigid 30-degree endoscope was inserted in the intrasellar and suprasellar regions in order to detect residual adenoma tissue. These residues were removed when technically possible.

RESULTS

No rhinologic complication was noted. In 7 patients, the intra- and suprasellar endoscopic view detected a tumor residue which could be removed in each case. Two cases of cerebrospinal fluid leakage occurred during the complementary tumor resection. Two cases of diabetes insipidus and two of rhinorrhea were reported postoperatively. The analysis of the postoperative MRIs showed a complete removal in 23% of the patients (3/13), 75 to 100% removal in 54% of the patients (7/13), 50 to 75% removal in 8% of the patients (1/13) and 50% removal in 15% of the patients (2/13). More than 75% removal was thus achieved in 77% of the patients (10/13). The mean follow-up was 27.2 months.

CONCLUSIONS

Rhinologic morbidity was reduced with the endoscopic endonasal approach. Endoscopy complemented with a microscope offered an optimal view of the intra- and suprasellar regions. Endoscopy also improved tumor resection of the invasive endo- and suprasellar pituitary macroadenomas by visualizing hidden suprasellar tumor residues. However, endoscopy was associated with a higher rate of postoperative rhinorrhea.

Variations on the Standard Transsphenoidal Approach to the Sellar Region, with Emphasis on the Extended Approaches and Parasellar Approaches: Surgical Experience in 105 Cases

OBJECTIVE:

The traditional boundaries of the transsphenoidal approach may be expanded to include the region from the cribriform plate of the anterior cranial base to the inferior clivus in the anteroposterior plane, and laterally to expose the cavernous cranial nerves and the optic canal. We review our combined experience with these variations on the transsphenoidal approach to various lesions of the sellar and parasellar region.

METHODS:

From 1982 to 2003, we used the extended and parasellar transsphenoidal approaches in 105 patients presenting with a variety of lesions of the parasellar region. This study specifically reviews the breadth of pathological lesions operated and the complications associated with the approaches.

RESULTS:

Variations of the standard transsphenoidal approach have been used in the following series: 30 cases of pituitary adenomas extending laterally to involve the cavernous sinus, 27 craniopharyngiomas, 11 tuberculum/diaphragma sellae meningiomas, 10 sphenoid sinus mucoceles, 18 clivus chordomas, 4 cases of carcinoma of the sphenoid sinus, 2 cases of breast carcinoma metastatic to the sella, and 3 cases of monostotic fibrous dysplasia involving the clivus. There was no mortality in the series. Permanent neurological complications included one case of monocular blindness, one case of permanent diabetes insipidus, and two permanent cavernous cranial neuropathies. There were four cases of internal carotid artery hemorrhage, one of which required ligation of the cervical internal carotid artery and resulted in hemiparesis. The incidence of postoperative cerebrospinal fluid fistulae was 6% (6 of 105 cases).

CONCLUSION:

These modifications of the standard transsphenoidal approach are useful for lesions within the boundaries noted above, they offer excellent alternatives to transcranial approaches for these lesions, and they avoid prolonged exposure time and brain retraction. Technical details are discussed and illustrative cases presented.

Endoscopy and Transsphenoidal Surgery

ENDOSCOPY OFFERS INTERNAL visualization of many different cavities of the human body, with its specific vision inside the anatomy, close to the target area. The view of the surgical field in transsphenoidal surgery had been obtained with the naked eye from its beginning in 1907 up to the introduction of the operating microscope by Jules Hardy in the 1960s, which represented a great advance in terms of magnification and illumination. In the past decade, modern rigid endoscopes, with their wider view near the relevant anatomy, have permitted minimally traumatic transsphenoidal procedures in and around the sellar area, thus representing a "new wave" in transsphenoidal history. An overview of the evolution of the endoscope as a visualizing and operating instrument particularly related to the transsphenoidal approach is presented here. The current possibilities of transsphenoidal endoscopy, with its related advantages and limitations, are presented.

[Trans-septal endoscopic approach of pituitary tumors]

The advances in endoscopic instruments have eased the approach to the sellar region through the nasal cavity. We carry out an analysis of the surgical results on 20 patients that underwent surgery for sellar tumours through a transeptal-transphenoidal approach in the last 2 years in our hospital. The average was 45.6 years old, and 75% were females. 30% of cases were pituitary adenomas and another 30% acromegaly, 25% Cushing's disease and 10% prolactinomas. No complications were encountered during surgery being the most common postoperative complications, diabetes insipida in two cases (10%) and CSF leak in one case. At present 2 patients are having hormonal treatment for panhypopituitarism. No patients developed a septal perforation, nasal deformity, epistaxis, meningitis, lip numbness or oronasal fistula. The rest did have good results noith no recurrence and hormonal values back to normal.

Novel closure technique for the endonasal transsphenoidal approach. Technical note

Transsphenoidal microsurgery has been the standard approach to sellar lesions since the repopularization of the technique with modifications by Dott, Guiot, and Hardy. The endonasal transseptal transsphenoidal approach, as introduced by Hirsch, is still commonly used by pituitary surgeons to remove lesions of the sellar and parasellar region. One disadvantage of this approach is that the submucosal dissection requires postoperative nasal packing, which is a source of discomfort in patients who undergo transsphenoidal surgery. The authors describe a novel closure technique for the unilateral endonasal transsphenoidal approach that eliminates the need for full nasal packing, minimizing postoperative rhinological morbidity. This technique has been performed in 67 patients harboring sellar and parasellar lesions. All patients recovered rapidly without significant rhinological sequelae.