The neurosurgical anatomy of the sphenoid sinus and sellar floor in endoscopic transsphenoidal surgery

Morphometric analysis of transsphenoidal surgery in Peruvian population

Background

Transsphenoidal surgery has become a key element in the approach to skull base pathologies. The objective of the study was to explore the morphometry of the sphenoidal region in the Peruvian population, with an emphasis on understanding its specific anatomical characteristics and providing quantitative data for the planning of transsphenoidal surgery.

Methods

A cross-sectional study included a random sample of 81 cases of healthy individuals who presented to the Radiology Department of a Private Hospital Center in Peru over 1 year. Skull computed tomography scans without contrast were performed, and a detailed morphometric analysis was conducted by an expert neurosurgeon, including measurements of four parameters to evaluate the anatomy of the craniofacial region.

Results

Most participants exhibited complete sellar pneumatization, followed by incomplete sellar pneumatization, while conchal pneumatization was rare. Significant differences were found between men and women in the distance from the nasal opening to the dorsum of the sella turcica. No significant gender differences were observed in other anatomical measurements or significant changes with age in anatomical measurements.

Conclusion

Morphometric analysis provides crucial data for the precise customization of surgical interventions in the Peruvian population, especially in transsphenoidal surgery. The results highlight the importance of considering individual anatomical differences and gender variability during surgical planning. Morphometry emerges as a valuable tool to enhance the quality and safety of transsphenoidal surgery by adapting surgical strategies to the specific anatomical dimensions of each patient.

Magnetic Resonance Imaging Features of the Sphenoid Sinus in Patients with Non-Functioning Pituitary Adenoma

Background and Objectives: A magnetic resonance imaging (MRI) scan is part of the diagnostic protocol in pituitary adenoma patients. The goal of the present study is to present and analyse the MRI appearances of the sphenoid sinus (SS) in patients with non-functioning pituitary adenoma (NFPA). Materials and Methods: This is a retrospective case-control study conducted between January 2015 and December 2023 in a tertiary referral hospital. Forty NFPA patients were included in the study group, while the control group consisted of 30 age- and gender-matched cases. Results: The sellar type of SS pneumatization was the most frequently encountered pattern among both groups. The presence of the lateral recess of the SS, mucosal cysts, and sphenoethmoidal cells was similar in both patient groups. The proportion of patients with SS mucosal thickness greater than 3 mm was 42.5% in NFPA group and 3% in the control group, and this difference was statistically significant (p < 0.001). The space between the two optic nerves was significantly larger in the NFPA group as compared to the control group (p < 0.001). Conclusions: Our study was able to establish a statistically significant association between the presence of NFPA and both the thickening of the SS mucosa and increased space between optic nerves.

Computed tomography-based assessment of sphenoid sinus and sella turcica pneumatization analysis: a retrospective study

Background

A preoperative three-dimensional examination of the sphenoid sinus anatomy, its pneumatization pattern, and its relevance to neighboring neurovascular constructions is crucial to preventing possible complications. In this study, the aim was to evaluate the relationship between sphenoid sinus pneumatization types and the sella turcica using computed tomography (CT).

Methods

CT data from 420 patients referred to the Department of Dentomaxillofacial Radiology were evaluated retrospectively. Sella pneumatization types were classified as conchal, presellar, incomplete sellar, and complete sellar, and they were evaluated. Obtained data were evaluated using the IBM SPSS 25.0 (Armonk, New York, USA) package program.

Results

CT images of 420 individuals, including 174 women and 246 men with a mean age of 43.87 ± 17.58 years, were included in the study. When the sella turcica morphologies were evaluated, the most widespread morphological type was irregularity in the posterior part of the dorsum sella, in 51.2% of cases. In addition, a statistically significant correlation was found between the pneumatization of the sphenoid sinus and the morphological types of sella (p < 0.05).

Conclusion

In this research endeavor, the predominant observation comprised the complete sellar sphenoid sinus pneumatization type, exhibiting irregularity in the posterior aspect of the dorsum sella, representing one of the sellar types. Notwithstanding, it is imperative to conduct additional investigations to establish the generalizability of the present study's findings.

Tips and Tricks to Safely Perform an Endoscopic Endonasal Trans-Sphenoidal Pituitary Surgery: A Surgeon's Checklist

The authors aimed to develop an extensive preoperative checklist of CT scan findings during endoscopic access to the ventral skull base and implement it in clinical practice. A comprehensive literature review was conducted to identify the radiological landmarks crucial to endoscopic skull base surgery. Four electronic databases were searched: PubMed, MEDLINE, EMBASE, and Google Scholar using search terms/keywords such as "radiological landmarks," "endoscopic skull base surgery," "CT scan," "pituitary surgery," "anatomical variations," "internal carotid," "optic nerve," "sphenoid sinus," "pneumatization," "dehiscence," and "protrusion". Inclusion criteria were limited to original articles and systematic reviews published in English, between the years 2000 and 2021, which pertained to the radiological landmarks to be identified during endoscopic skull base surgery. Full-text articles were retrieved and collated into a narrative review focused on a 12-item checklist the authors agreed upon. The mnemonic "O ROAD TO SELLA" was used to represent the checklist and include the following landmarks: Sphenoid Ostium, Sphenoid Rostrum, Onodi cells, Anatomic variations of the sphenoid sinus, Distance between the carotids, Tumor characteristics, Optic nerve dehiscence/protrusion, Septation/insertion of the sphenoid sinus, Entrance to the sellar floor, Lateral recess of the sphenoid sinus, cLinoid process pneumatization, and internal carotid Artery dehiscence/protrusion. The checklist is designed to be used by attending physicians, fellows, and residents and the authors intend to implement it into electronic medical records at the institution's medical center to monitor the outcomes of EEPS after implementation.

Endoscopic endonasal transsphenoidal surgery in acromegaly with conchal sphenoid sinus

BACKGROUND

A conchal non-pneumatized sphenoid sinus tends to be considered as unfavorable for transsphenoidal surgery because of procedural difficulties. Especially in acromegalic patients, the proportion of the conchal type of sphenoid sinus is potentially high compared with that of other patients who have a pituitary tumor. This report investigates the characteristics and surgery of the conchal type of sphenoid sinus in acromegaly along with the internal bone properties.

CLINICAL PRESENTATION

A 70-year-old man with acromegaly underwent endoscopic endonasal transsphenoidal surgery. Intraoperatively, the anterior wall of the non-pneumatized sphenoid was cortical, however, the cancellous bone was very soft, included fatty tissue, and was easily removed by suction. The sellar lesion could be reached without any problems, and finally, total tumor resection was achieved.

CONCLUSION

Based on this surgical case, the conchal sphenoid sinus of acromegaly is not always homogeneous solid bone but may contain soft fatty tissue. Therefore, although the sphenoidal characteristics may have an impact on the surgical procedures, precise assessment pre- and intraoperatively can make transsphenoidal surgery with conchal sphenoid sinus feasible.

Morphological and Metrical Relationships Between Sphenoid Sinus and Sella Turcica: Possible Applications in Transnasal Transsphenoidal Surgery

INTRODUCTION

Transsphenoidal surgeries imply the risk of intraoperative lesions to the neurovascular structures surrounding the sphenoid sinus (SS). Aim of the present study is to assess the metrical and morphologic relationships existing between SS and sella turcica (ST).

MATERIALS AND METHODS

Two hundred computed tomography-scans of patients were selected. For each patient volumes of SS were calculated from their 3-dimensional models segmented through ITK-SNAP program. Variants of SS in pneumatisation and sellar diameters [antero-posterior (AP) diameter, depth, and length] were evaluated on each computed tomography-scan. Correlations among different measurements were assessed through Spearman test ( P <0.01), whereas associations between sellar parameters and presence of pneumatisation variants were assessed through Mann-Whitney test ( P <0.01).

RESULTS

In males, pneumatization of the greater wings was related to smaller AP diameter ( P <0.01) and depth of ST ( P <0.01), whereas in females lower values of depth were found in patients with pneumatization of the pterygoid processes ( P <0.01). In both sexes, a positive correlation was found between AP diameter and, respectively, length and depth of ST ( P <0.01), together with a negative correlation between volume of SS and depth of ST ( P <0.01). Lastly, in females a positive correlation was found between age and, respectively, length and depth of ST ( P <0.01).

CONCLUSIONS

The present study highlighted new metrical and morphologic relationships between volume and pneumatisation of SS and diameters of ST. Knowledge of these correlations allows to understand more clearly, in the preoperative setting, the surgical working space. Further studies are needed, especially for what concerns the relationship between sellar measurements and age in females.

History, Current Techniques, and Future Prospects of Surgery to the Sellar and Parasellar Region

The sellar and parasellar region can be affected by diverse pathologies. The deep-seated location and surrounding critical neurovascular structures make treatment challenging; there is no singular, optimal approach for management. The history and development of transcranial and transsphenoidal approaches by pioneers in skull base surgery were largely aimed at treating pituitary adenomas, which are the most common lesions of the sella. This review explores the history of sellar surgery, the most commonly used approaches today, and future considerations for surgery of the sellar/parasellar region.

The Party Wall: Redefining the Indications of Transcranial Approaches for Giant Pituitary Adenomas in Endoscopic Era

The evolution of endoscopic trans-sphenoidal surgery raises the question of the role of transcranial surgery for pituitary tumors, particularly with the effectiveness of adjunct irradiation. This narrative review aims to redefine the current indications for the transcranial approaches for giant pituitary adenomas in the endoscopic era. A critical appraisal of the personal series of the senior author (O.A.-M.) was performed to characterize the patient factors and the tumor's pathological anatomy features that endorse a cranial approach. Traditional indications for transcranial approaches include the absent pneumatization of the sphenoid sinus; kissing/ectatic internal carotid arteries; reduced dimensions of the sella; lateral invasion of the cavernous sinus lateral to the carotid artery; dumbbell-shaped tumors caused by severe diaphragm constriction; fibrous/calcified tumor consistency; wide supra-, para-, and retrosellar extension; arterial encasement; brain invasion; coexisting cerebral aneurysms; and separate coexisting pathologies of the sphenoid sinus, especially infections. Residual/recurrent tumors and postoperative pituitary apoplexy after trans-sphenoidal surgery require individualized considerations. Transcranial approaches still have a critical role in giant and complex pituitary adenomas with wide intracranial extension, brain parenchymal involvement, and the encasement of neurovascular structures.

Surgical and Radiological Differences in Intersphenoid Sinus Septation and the Prevalence of Onodi Cells with the Endoscopic Endonasal Transsphenoidal Approach

Background and Objectives: Understanding the anatomical variation in the sphenoid sinus is important to fully expose the sellar floor and clivus. Materials and Methods: The Onodi cell and intersphenoid sinus septation based on preoperative paranasal sinus computed tomography (PNS CT) and the surgical records of 877 patients who underwent the endoscopic endonasal transsphenoidal approach (EETSA) were retrospectively reviewed. Results: An intersphenoid sinus septum (ISS) blocking the clivus was defined as a pseudoclivus. Complete and incomplete pseudoclivuses were found in 2.97% and 10.5% of patients, respectively. Intraoperative and PNS CT ISS findings differed in 17.1% of patients. Misconceptions regarding a ridge or vertical ISS and confusion between an incomplete pseudoclivus and a vertical ISS were common. Conclusions: Because intraoperative and PNS CT findings may differ, anatomical variation in the paraclival area should be evaluated carefully. A pseudoclivus mimicking the clivus is important to attain a fully exposed EETSA surgical view.

Predictors of the Size and Surgical Freedom of the Trans-Cribriform and Trans-Clival Corridors, a Radiographic Analysis

Introduction The transcribriform and transclival corridors are endoscopic endonasal approaches used to treat pathologies of the skull base. We present a predictive model that uses the clival length and ethmoidal width to predict the size and surgical freedom (SF) of these corridors.

Methods Adult facial computed tomography scans were reviewed. Exclusion criteria included patients <18 years of age or radiographic evidence of trauma, neoplasm, or congenital deformities of the skull base. The images were analyzed using OsiriX MD (Bernex, Switzerland). Patients' demographics, clival length, ethmoidal width, surface area, and others were collected. Linear regression was used to create prediction models for the size and SF of the transclival and transcribriform corridors.

Results A total of 103 patients were included with an average age of 44.9 years and 47% males. Females had a smaller clival surface area (8 vs. 9.2 cm2, p = 0.001). For transclival corridor, clival length correlated positively with SF in the sagittal plane (rho = 0.44, p < 0.05) and negatively with SF in the coronal plane (rho = − 0.2, p < 0.05). For transcribriform corridor, ethmoidal width correlated positively with SF in the coronal plane (rho = 0.74, p < 0.05), and negatively with SF in the sagittal plane (rho = − 0.2, p < 0.05).

Conclusion A significant variability of the bony anatomy of the anterior and central skull base was found. The use of clival length and ethmoidal width as part of preoperative surgical planning might help to overcome the anatomical variability which could affect the adequacy of surgical corridors.

Sellar, suprasellar, and parasellar masses: Imaging features and neurosurgical approaches

The sellar, suprasellar, and parasellar space contain a vast array of pathologies, including neoplastic, congenital, vascular, inflammatory, and infectious etiologies. Symptoms, if present, include a combination of headache, eye pain, ophthalmoplegia, visual field deficits, cranial neuropathy, and endocrine manifestations. A special focus is paid to key features on CT and MRI that can help in differentiating different pathologies. While most lesions ultimately require histopathologic evaluation, expert knowledge of skull base anatomy in combination with awareness of key imaging features can be useful in limiting the differential diagnosis and guiding management. Surgical techniques, including endoscopic endonasal and transcranial neurosurgical approaches are described in detail.

Sphenoid sinus mucosal thickening in patients with non-functioning pituitary adenoma

AIM

The aim of this study was to evaluate magnetic resonance imaging findings of sphenoid sinus (SS), pituitary gland and related structures in patients with non-functioning pituitary adenoma (NFPA) and compare to a control group.

METHODS

This study was conducted in a tertiary referral hospital between January 2018 and July 2020. Sixty-five patients diagnosed with NFPA and age- and gender-matched controls (n = 40) were included.

RESULTS

The average age in the NFPA group was 37.46 ± 11.2 years and in the control group was 41.97 ± 14.88 years, and they did not differ significantly (P = .103). SS mucosal thickness greater than 1 mm was determined in a higher proportion of NFPA (67.7%) than in the control group (12.5%) (P < .001). A mucosal thickness greater than 3 mm was only present in the NFPA group (43.1%). The distance between optic nerves was significantly longer in the NFPA group compared with control (P < .001). There was a strong positive correlation between adenoma volume and distance between the two optic nerves (r = .728, P < .001). Also, there was a moderate positive correlation between adenoma volume and petrous intercarotid distance (ICD) (r = .561, P < .001) and a low positive correlation between adenoma volume and cavernous ICD (r = .408, P < .001).

CONCLUSIONS

The present study showed an association between NFPA and both SS mucosal thickening and increased distance between optic nerves. Also, our study demonstrated that there was a strong positive correlation between adenoma volume and distance between the two optic nerves.

Patterns of extrasellar invasive growth of pituitary adenomas with normal sellar cavity size

BACKGROUND

Pituitary adenomas (PAs) are among the most common brain tumors which characteristically become symptomatic due to the mass effect on surrounding structures and/or hormonal imbalances. This study describes 28 cases of PAs with an extrasellar invasive growth (EIG) at the early stage of tumor growth with normal sellar cavity size.

METHODS

1200 cases of PAs either treated medically or via Endoscopic transsphenoidal surgery were reviewed during a 10-year period. Pre-operative imaging was analyzed to evaluate the tumor expansion pattern, tumor invasion sites and other relevant tumor properties. A comprehensive preoperative endocrinological along with postoperative histopathological studies were conducted to evaluate the subjects' homeostasis and further identify the lesions characteristics.

RESULTS

Of the 28 patients, patients 19, 2, 1 and 6 had a growth hormone (GH)-secreting PA, an adrenocorticotropic hormone (ACTH)-secreting PA, a nonfunctional PA (NFPA) and a mix-hormones secreting PA, respectively. There was a statistically significant difference between patients with and without EIG regarding types of PAs (P = 0.000). Post-hoc tests demonstrated that GH-secreting PAs (P = 0.0003) and mix-hormones secreting PAs (P = 0.0000) are significantly more invasive, while NFPAs (P = 0.0000) are less invasive. There was not a statistically significant difference between the invasion sites and different types of PAs (P = 0.122).

CONCLUSION

Among different histological subtypes of PAs, GH-secreting PAs revealed a remarkable tendency for EIG with normal sellar cavity size. The extra-sellar tumor extension with a normal sella did not correlate with atypical histology. Considering EIG patterns, surgeons should be vigilant to investigate and follow the tumor spreading to its enclosing boundary during surgery, the clival part of sphenoid bone should be more exposed, and both inferomedial and lateral borders of the sphenoid sinus should be carefully explored in order to remove the tumor.

Assessment of variations in sphenoid sinus pneumatization in Indian population: A multidetector computed tomography study

Background and Purpose:

The purpose of our study was to assess the prevalence of variations in the extent of sphenoid pneumatization in the Indian population and compare with existing literature.

Materials and Methods:

This retrospective study included 500 patients who underwent CT of the paranasal sinuses. The multiplanar reformations of paranasal sinus were assessed for the type of pneumatization of the sphenoid sinus and type of clival, lateral recess, lesser wing, and anterior recess extensions.

Results:

The conchal, presellar, incomplete sellar, and complete sellar types comprised 0%, 1.2%, 22.2%, and 76.6% of patients. The extensions of pneumatization subtypes in the study population were clival in 76.6% subjects; lateral recess, lesser wing, and anterior recess in 59.7%, 20.4%, and 20.4% of sinuses, respectively. The pure forms were seen in 25.4% and combined forms in 61% of sinuses. The presellar type (1.2%) was less common and sellar type (98.8%) being common in our population compared to the Caucasian and East Asian population. The sphenoid sinuses were extensively pneumatized in our population compared to the Chinese and Caucasian population, the prevalence being 76.6%, 68%, and 44.5% for clival; 59.7%, 46%, and 28.3% for lateral recess; 20.4%, 32%, and 12% for lesser wing extension, respectively. The pure forms were relatively less common and combined forms being more common compared to the Chinese and Caucasian population in our study.

Conclusion:

The extent of pneumatization of the sphenoid sinus has clinical and surgical implications in sellar and central skull base lesions, and variability in different populations confirms that ethnicity influences the differences in prevalence.

The sphenoethmoidal sinus and the modified anatomy of the related structures

The anterior extent of the sphenoidal sinus in the posterior ethmoid was less investigated. Our purpose was to study whether, or not, the occurrence of a sphenoethmoidal sinus (SES) relates to a sagitally-shortened ethmoid. A retrospective cone-beam computed tomography (CBCT) was performed on 36 patient files. In six patients were found SES extended anteriorly above the posterior third of the middle turbinate (MT). Two of these patients had bilateral SES with ethmoidal chambers included in the lateral and superior nasal walls and draining in the sphenoethmoidal recesses. The correlation between the nasion-to-concha sphenoidalis distance and the presence of SES was statistically significant (less than 40 mm in SES cases and more than 40 mm in non-SES cases). We also found: (i) superior turbinates (STs) with ethmoidal and sphenoidal insertions on one side and ethmoidal and maxillary insertions on the opposite side (the maxillary insertion of ST modifies surgical landmarks and was not previously reported), (ii) MT perforation and (iii) pterygoid recess of the maxillary sinus located beneath the pterygopalatine ganglion fossa. The SES thus shortens sagitally the lateral nasal wall but does not modify its morphology. The MT perforation, ST maxillary insertion and the pterygoid recess are rare anatomic variants not reported previously in our knowledge.

A neurosurgical assessment of the blood supply in the optochiasmatic system: a cadaveric-anatomic study

The chiasmal and subchiasmal surfaces are of critical importance in connection with the performance of surgical procedures owing to the critical blood supply to these areas. Recently, the perforating arteries providing the blood to the optic nerves and chiasm have gained attention as they significantly affect the morbidity from surgical approaches. Intraoperative preservation of these perforating arteries is considered critical to prevent further visual loss. Thirty autopsy specimens, including the optic apparatus, were examined for their perforating arteries feeding the optic chiasm and optic nerves. The optic nerves and chiasmal surfaces were divided into four zones based on the presence and numbers of perforating arteries as anterior superior-posterior superior surfaces and anterior inferior-posterior inferior surfaces. The superior surface of the optic chiasm was supplied by the A1 segments of the bilateral anterior cerebral arteries and by the perforating arteries originating from the anterior communicating artery. On the other hand, the inferior surface of the optic chiasm was fed by the bilateral posterior communicating arteries and by the supraclinoidal segments of the bilateral carotid arteries. We demonstrated the anatomical involvement of a large number of nourishing arteries in feeding the optic apparatus related to the perforating arteries by classifying them into zones based on the surgical approaches, which has been rarely reported in the literature.

Do Not Give Up on Ossified Tuberculum Sellae Meningioma - Vision Restored

This case report accompanies a video of the treatment of a Tuberculum sellae meningioma (TSM) in a woman that presented with left eye near-blindness. The senior author conducted the operation via a pterional retractorless approach, and the patient had a full recovery. This case report discusses the unique anatomy of conchal sphenoid sinus, ossified TSM with very calcified consistency, and retractorless brain microsurgery. The resection of ossified TSM is still safe and viable with adequate microsurgical techniques and skull base instruments without compromising the neurovascular structure and with good neurological and visual outcomes for the patient.

An advanced protocol for intraoperative visualization of sinunasal structures: experiences from pituitary surgery

OBJECTIVE

The transsphenoidal route to pituitary adenomas challenges surgeons because of the highly variable sinunasal anatomy. Orientation may be improved if the appropriate information is provided intraoperatively by image guidance. The authors developed an advanced image guidance protocol dedicated to sinunasal surgery that extracts information from multiple modalities and forms it into a single image that includes fine sinunasal structures and arteries.The aim of this study was to compare the advantages of this novel image guidance protocol with the authors' previous series, with emphasis on anatomical structures visualized and complication rate.

METHODS

This retrospective analysis comprised 200 patients who underwent surgery for pituitary adenoma via a transnasal transsphenoidal endoscopic approach. The authors' standard image guidance protocol consisting of CT for solid bone, T1CEMRI for soft tissues, and MRA for the carotid artery was applied in 100 consecutive cases. The advanced image guidance protocol added a first-hit ray casting of the CT scan for visualization of fine sinunasal structures, and adjustments to the MRA to visualize the sphenopalatine artery (SPA) were applied in a subsequent 100 consecutive cases.

RESULTS

A patent sphenoid ostium-i.e., an ostium not covered by a mucosal layer-was visualized significantly more often by the advanced protocol than the standard protocol (89% vs 40%, p < 0.001) in primary surgeries. The SPA and its branches were only visualized by the advanced protocol (87% and 91% of cases in primary surgeries and reoperations, respectively) and not once by the standard protocol. The number of visualized complete and incomplete sphenoid septations matched significantly more commonly with the surgical view when using the advanced protocol than the standard protocol at primary operation (mean 1.9 vs 1.6, p < 0.001). However, in 25% of all cases a complex and not a simple sinus anatomy was present. In comparison with the intraoperative results, a complex sphenoid sinus anatomy was always detected by the advanced but not by the standard protocol (25% vs 8.5%, p = 0.001).Furthermore, application of the advanced protocol reduced the cumulative rate of complications (25% vs 18% [standard vs advanced group]). Although an overall significant difference could not be determined (p = 0.228), a subgroup analysis of reoperations (35/200) revealed a significantly lower rate of complications in the advanced group (5% vs 30%, p = 0.028).

CONCLUSIONS

The data show that the advanced image guidance protocol could intraoperatively visualize the fine sinunasal sinus structures and small arteries with a high degree of detail. By improving intraoperative orientation, this may help to reduce the rate of complications in endoscopic transsphenoidal surgery, especially in reoperations.

Anatomical location of the abducens nerves (VI) in the ventral approach of clival tumors

The aim of this work was to determine reliable anatomical landmarks for locating and preserving the abducens nerves (6th cranial nerves) during trans-facial or trans-nasal endoscopic approaches of skull base tumors involving the clivus and the petrous apex. In order to describe this specific anatomy, we carefully dissected 10 cadaveric heads under optic magnification. Several measurements were taken between the two petro-sphénoidal foramina, from the bottom of the sella and the dorsum sellae. The close relationship between the nerves and the internal carotid artery were taken into account. We defined a trapezoid area that allowed drilling the clivus safely, preserving the 6th cranial nerve while being attentive to the internal carotid artery. The caudal part of this trapezium is, on average, 20 mm long at mi-distance between the two petro-sphenoidal foramina. The cranial part is at the sella level, a line between both paraclival internal carotid arteries. Oblique lateral edges between the cranial and caudal parts completed the trapezium.

Transnasal Transsphenoidal Approach for Pituitary Tumors: An ENT Perspective

Endoscopic transnasal transsphenoidal (ETNTS) approach was first described in 1992 and is standard approach for the resection of benign pituitary adenomas. This prospective study aims in incidence and preoperative assessment of extent of the pituitary adenoma, peroperative findings of transnasal transsphenoidal excision, techniques of skull base repair, complications and its management in a tertiary centre. A prospective analysis from Jan 2017 to May 2019, of patients undergoing ETNTS approach of pituitary adenomas was made in terms of incidence in various age-groups, type of adenoma, operative findings including CSF leak, repair of the skull base defect, complications encountered and its management was done in a tertiary care centre and compared with the present literature. A total of 141 patients underwent ETNTS, with highest number of cases found in 41-50 years age-group with mean age of 42.6 years. Male: Female ratio was 1.6. Macroadenoma was in 123 patients while 18 had microadenoma, of these 63.74% were functional adenoma, highest of GH secreting, while 36.26% were non-functional. Mean surgical time was 98.4 min ± 21.2 min. Peroperative CSF leak was in 30.5% cases in various grades. Closure techniques included use of fat, multilayer techniques, Hadad's flap and gasket technique as per the type of CSF leak. Neurological and rhinological complications were 6.38% each. This study is focused on the ENT perspective of the endoscopic transnasal trans-sphenoidal approach for pituitary adenomas. The reduced rate of morbidity and complications is encouraging. The endoscopic skull base defect closure is challenging and requires skill, meticulous approach and synchronised team work in order to achieve a favourable outcome. The incidence of CSF leak can be minimised and if encountered has to be dealt in an organised manner, thus contributing to a reduced rate of complications. The complications encountered must be foreseen and managed with a proficient approach.

Sphenoid sinus septations and their interconnections with parasphenoidal internal carotid artery protuberance: radioanatomical study with literature review

Introduction

Internal carotid artery (ICA) injury is the most dangerous and life-threatening complication in patients operated on due to parasellar tumors via a minimally invasive endoscopic endonasal approach. Sphenoid septal attachment to the ICA protuberance within the sphenoid sinus was found to be one of the anatomical risk factors for ICA injury during transsphenoidal surgery.

Aim

To determine the relationship between the sphenoid sinus septa and the parasellar or paraclival internal carotid artery prominence based on our own material and a literature review.

Material and methods

The axial plane scans of computed tomography angiography and a literature review of previously published papers on the septum variation and its connection with the ICA prominence are provided.

Results

Out of 100 sphenoid sinuses, 49 (49%) had at least one septum inserted at the ICA prominence. In the majority of cases 42 (86%) one septum was inserted at the prominence of one of the ICAs. In 7 (14%) cases, two separate septa were inserted at the prominences of both ICAs. Patients with multiple septa and those having an incomplete septum were at higher risk of at least one of them being inserted at the ICA prominence within the sinus. Including cases from the literature review, the average number of septa per patient was 1.42. The risk of intersection between the septum and the ICA prominence was 32%.

Conclusions

A significant percentage of the intrasphenoidal septa are inserted at the sphenoidal ICA protuberance.

Assessment of sphenoid sinus types in patients with cleft lip and palate on cone-beam CT

PURPOSE

The aim of this study is to examine the sphenoid sinus morphology and variations in patients with cleft lip and palate (CLP) on cone-beam computed tomography (CBCT) images, and to compare them with healthy controls.

METHODS

CBCT images of 54 patients (28 males and 26 females,) with CLP and 54 age- and gender-matched healthy individuals (28 males and 26 females) were retrospectively evaluated. Sphenoid sinus main types (conchal, presellar, sellar, postsellar), sellar subtypes, clival and lateral extensions, and sinus septation were analyzed in CLP and control groups. The data were statistically analyzed using Chi-square test to compare the groups.

RESULTS

A statistically significant difference was found between CLP and control groups for sphenoid sinus main types (p < 0.05). Presellar type was more commonly observed in CLP group (18.5%), while the postsellar (31.5%) and clival (17.7%) types were more frequent in control group. There was a significant difference between the groups among different sellar sinus subtypes (p < 0.05). A significant difference was detected between the groups for clival extensions of sphenoid sinus (p < 0.05), but no difference was found for the lateral extensions (p > 0.05). No significant difference was determined between groups for sphenoid sinus septation (p > 0.05).

CONCLUSION

Significant differences were found between the CLP and control groups in terms of sphenoid sinus main types, sellar subtypes and the clival extensions. Knowledge of sphenoid sinus pneumatization in patients with CLP is important for preventing complications during transsphenoidal surgery.

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.

Measurements and Clinical Application of Anatomical Space for Transfrontal Pituitary Surgery Through Magnetic Resonance Imaging Reconstruction

OBJECTIVE

This study aims to clarify the relative position of the normal important structures and anatomical spaces formed by the structures passed through during the transfrontal pituitary surgery, and discuss how to avoid some eloquent structures.

METHODS

A total of 120 cases of magnetic resonance imaging images from normal adult brains were selected as the object of study and divided into male and female groups. The important adjacent structures of the pituitary passed through during the transfrontal pituitary surgery were marked on the reconstructed images. In all planes of the spaces passing through successively during the pituitary surgery, the morphological parameters such as the size, boundary, structure, and spatial extent of the spaces were measured.

RESULTS

The size, boundary, structure, and spatial extent of the space between the 2 optic nerves, the space between the optic nerves and the pituitary stalk, and the space between the tuber cinereum and the interal carotid artery in the plane of the pituitary stalk were measured, the anterior part and the posterior part in male were shorter than those in female (P = 0.021; P = 0.029); no statistically significant difference was found in the measurements of the lengths and angles of these spaces.

CONCLUSIONS

The authors' findings provide the surgeons with the detailed anatomical data and help to provide a morphological basis for intraoperative protection of the pituitary and vital adjacent structures and surgical approach.

Management of non-functioning pituitary adenomas: surgery

Non-functional pituitary adenomas (NFPAs) are benign tumors of the pituitary gland that do not over-secrete hormonal products, therefore, they are generally detected through symptoms of mass effect, including headache, vision loss, or hypopituitarism. There are multiple pathological subtypes of NFPAs, such as null cell adenomas, silent gonadotrophs, silent somatotrophs, silent corticotrophs, and silent subtype 3, all of which can be classified based on immunohistochemical studies and electron microscopy. Despite these numerous pathological subtypes, surgical resection remains the first-line treatment for NFPAs. Diagnosis is best made using high resolution MRI brain with and without gadolinium contrast, which is also helpful in determining the extent of invasion of the tumor and recognizing necessary sinonasal anatomy prior to surgery. Additional pre-operative work-up should include full laboratory endocrine evaluation with replacement of hormone deficiencies, and ideally, full neuro-ophthalmologic exam. Although transcranial surgical approaches to the pituitary gland can be performed, the most common approach used is the transnasal transsphenoidal approach with endoscopic or microscopic visualization. This approach avoids retraction of the brain and cranial nerves during tumor removal. Surgery for symptoms caused by mass effect, including headaches and visual loss, are successfully treated with surgical resection, resulting in improvement in pre-operative symptoms as high as 90% in some reports. Although the risk of complications is low, major and minor events, such as permanent hypopituitarism, persistent CSF leak, and carotid artery injury can occur at rates ranging from zero to about 9%.

Intracranial Anatomic Landmarks for Endoscopic Endonasal Transcribriform Approach to Anterior Skull Base

OBJECTIVES

To help surgeons locating anatomic landmarks when performing endoscopic endonasal transcribriform approach to anterior skull base.

METHODS

High-resolution axial computed tomography (CT) images at thickness of 0.6 mm, and reconstructed 0.41-mm thick gapless sagittal and coronal CT images were taken from 123 subjects. Using mimics software, first located elementary points and line: nasal spine, midpoint of posterior hard palate and the line between them; then located measured points right/left posterior and anterior points; measured distances between measured points and from measured points to nasal spine and angles between lines connecting measured points to nasal spine and the basic line.

RESULTS

The distances from nasal spine to right/left posterior and anterior points of anterior skull base are 68.67 ± 6.04 and 61.71 ± 5.09 mm, corresponding angles are 45.89 ± 4.20° and 72.07 ± 4.06°, respectively. The width and length of defect of anterior skull base are 24.45 ± 2.62 and 31.03 ± 4.96 mm; its area ranges from 373.75 ± 94.08 to 800.91 ± 195.07 mm.

CONCLUSIONS

The study provides information about anterior skull base anatomic landmarks, which can help surgeons to locate them and avoid relative complications during endoscopic endonasal transcribriform approach to anterior skull base. The measurements can be used as surgical indicators to investigate the landmarks.

Outcomes After Transcranial and Endoscopic Endonasal Approach for Tuberculum Meningiomas-A Retrospective Comparison

BACKGROUND

Degree of resection and visual outcome are the main concerns in the surgical resection of tuberculum sellae meningioma (TSM). In addition to the transcranial approach (TCA), the endoscopic endonasal approach (EEA) has been used increasingly. However, the controversy regarding the optimal surgical approach is not clearly resolved.

METHODS

We compared the surgical outcomes of each approach for TSMs from 44 patients receiving EEA and 40 patients receiving TCA in 2 institutions between 2004 and 2015. We analyzed the surgical outcomes and affecting factors for the relapse of tumor and visual outcome.

RESULTS

Gross total resection rates and relapse-free survival were not different between the 2 groups; however, the locations of residual or recurred tumor definitely differed. All recurrences in the TCA group were in the sella turcica, whereas residual tumors in EEA group were mainly located at lateral or superior to the clinoid process. The complete or partial improvement rate of visual function in the EEA group was 97.7%, but 9 patients (23.7%) in the TCA group experienced visual deterioration after surgery. EEA and younger age (<55 years) were associated with favorable visual outcome. Cerebrospinal fluid leakage occurred in only one case in the EEA group.

CONCLUSIONS

Surgical approaches do not affect the gross total resection rates, but the locations of residual tumor or recurrence differ according to surgical approaches. EEA is superior to TCA in visual outcome. At least in pure TSMs, the trend seems to be shifting in favor of EEA, considering the huge difference in visual outcome.

Contribution of sellar dura integrity to symptom manifestation in pituitary adenomas with intratumoral hemorrhage

PURPOSE

Although hemorrhage within pituitary adenomas frequently exacerbates the symptoms, there are many grades of severity. Moreover, the contributing factors for symptom severity are still controversial.

METHODS

This retrospective study included 82 patients who underwent transsphenoidal surgery for pituitary adenomas with intratumoral hemorrhage. The grades of preoperative symptoms were classified into group A, asymptomatic or minor symptoms; group B, moderate symptoms sufficient for complain; and group C, severe symptoms disturbing daily life.

RESULTS

The hemorrhage volume within an adenoma was significantly higher in group C (92.6%) than in groups A (48.6%) and B (58.7%). Both headache and diplopia were dominant in group C, occurring in 72.2% and 27.8% of the patients, respectively. In group C, there was no significant difference in frequency between adenoma extensions into the sphenoid sinus (0%) and involvement of the cavernous sinus of Knosp grade 4 (0%), and extensions into the suprasellar region were not common (38.9%). The most distinctive feature was that "no extrasellar extension" was found only in group C (41.2%), and "multidirectional extension" was not detected in this group (0%). Multiple regression analysis revealed that the most powerful determining factors were the high frequencies of intratumoral hemorrhage and lack of extrasellar and multidirectional extensions.

CONCLUSION

Rapid volume expansion of a hematoma and lack of extension or unidirectional extension might lead to significant compression of the sellar and surrounding structures. Of note, the integrity of the sellar dura might contribute to the acute onset of symptom manifestations caused by hemorrhage in pituitary adenomas.

Efficacy of sellar opening in the pituitary adenoma resection of transsphenoidal surgery influences the degree of tumor resection

Background

Endonasal transsphenoidal microsurgery is often adopted in the resection of pituitary adenoma, and has showed satisfactory treatment and minor injuries. It is important to accurately localize sellar floor and properly incise the bone and dura matter.

Methods

Fifty-one patients with pituitary adenoma undergoing endonasal transsphenoidal microsurgery were included in the present study. To identify the scope of sellar floor opening, CT scan of the paranasal sinus and MRI scan of the pituitary gland were performed for each subject. Intraoperatively, internal carotid artery injury, leakage of cerebrospinal fluid, and tumor texture were recorded, and postoperative complications and residual tumors were identified.

Result

The relative size of sellar floor opening significantly differed among the pituitary micro-, macro- and giant adenoma groups, and between the total and partial tumor resection groups. The ratio of sellar floor opening area to maximal tumor area was significantly different between the total and partial resection groups. Logistic regression analysis revealed that the ratio of sellar floor opening area to the largest tumor area, tumor texture, tumor invasion and age were independent prognostic factors. The vertical distance between the top point of sellar floor opening and planum sphenoidale significantly differed between the patients with and without leakage of cerebrospinal fluid.

Conclusion

These results together indicated that relatively insufficient sellar floor opening is a cause of leading to residual tumor, and the higher position of the opening and closer to the planum sphenoidale are likely to induce the occurrence of leakage of cerebrospinal fluid.

Pituitary macroadenoma: analysis of intercarotid artery distance compared to controls

Objective To evaluate the intercarotid distance (ICD) of patients with pituitary macroadenoma and compare to heatlhy controls. Method We retrospectively reviewed contrast-enhanced MRI images from twenty consecutive patients diagnosed with non-functioning pituitary macroadenoma, measured the ICD at two different levels (petrous segment - ICD1 and horizontal cavernous segment - ICD2) and compared to twenty paired controls. Results There was no statistically significant difference of the mean ICD1 between the groups and subgroups. For the ICD2 there was statistically significant difference between the case and controls. However, there was no significant difference between the patients with smaller adenomas and the controls. In contrast, the patients with giant adenomas showed statistically significantly higher ICD2 than the controls. Conclusion The ICD at the horizontal segment of the cavernous carotid tends to be wider in patients with giant pituitary adenomas than in healthy individuals or patients with smaller adenomas.

Anatomic Variations in Pituitary Endocrinopathies: Implications for the Surgical Corridor

Objectives/Hypotheses Functioning pituitary adenomas may produce endocrinopathies such as acromegaly and Cushing syndrome. Both conditions lead to characteristic anatomic variations as a result of hormonally induced abnormal soft tissue deposition. We evaluate the anatomic differences between acromegalics and Cushing disease patients and compare these dimensions to controls. Design Radiographic review of preoperative magnetic resonance images (MRI) of the pituitary gland. Setting Tertiary academic medical center. Participants Patients who underwent transnasal, transsphenoidal surgery for pituitary adenomas found to have acromegaly or pituitary Cushing between January 1, 2007 and September 1, 2015. A total of 15 patients with similar MRIs and no history of pituitary or sinonasal disease were selected as controls. Main Outcome Measures Dimensions assessed were intercarotid distance; carotid canal width; piriform aperture width; distance from the piriform aperture to the anterior face of the sphenoid; sphenoid sinus height, width, and length; angle from anterior nasal spine to anteroinferior face of sphenoid sinus; choanal height; and nasal cavity height at the level of the vertical segment of the middle turbinate. Sphenoid sinus pneumatization patterns were recorded. Results There were 30 acromegalics and 31 Cushing disease patients. When compared with controls, both acromegalics and Cushing disease patients had significantly wider piriform apertures and a longer distance from the piriform aperture to the anterior face of the sphenoid sinus (p < 0.05). Acromegalics had a significantly less acute angle (19 ± 3 degrees) from the anterior nasal spine to the sphenoid (p < 0.05). Cushing disease patients had significantly lower sphenoid sinus length and shorter nasal cavity height (p < 0.05). There were no differences in intercarotid distance or carotid canal width. Conclusions As acromegalics and Cushing disease patients have known anatomic variations, the skull base surgeon should be aware of these differences and adapt their techniques and approaches as needed.

Is Complex Sphenoidal Sinus Anatomy a Contraindication to a Transsphenoidal Approach for Resection of Sellar Lesions? Case Series and Review of the Literature

BACKGROUND

The transsphenoidal approach is considered the gold standard for resection of pituitary adenomas and other sellar region lesions. This approach is guided by a few fundamental anatomic landmarks that conduct the surgeon toward the sellar floor. Some anatomic structures may vary a lot (e.g., intrasphenoidal septa, intercarotid distance) and may be difficult to identify. Pneumatization and conformation of the sphenoidal sinus (SS) plays a key role in accessing the floor of the sella and other skull base structures. A poorly pneumatized SS may be a relative contraindication to the transsphenoidal approach. We analyzed outcome and complications in transsphenoidal surgery for sellar lesions with a difficult SS.

METHODS

We analyzed 243 consecutive patients who underwent a transsphenoidal approach for sellar lesions. Patients with poor pneumatization of the SS were included. Neurosurgical and endocrinologic outcomes were reported.

RESULTS

Successful treatment using a transsphenoidal approach with neuronavigation and Doppler ultrasound was achieved in 15 patients with a low degree of pneumatization of the SS. A pituitary adenoma was present in 13 of 15 patients. Endocrinologic and neurosurgical outcomes were similar to patients with normal pneumatization of the SS, showing a cure of disease in 6 of 9 patients with functioning adenomas and an improvement of symptoms in cases of nonfunctioning adenomas.

CONCLUSIONS

Patients with a poorly pneumatized SS can be treated safely with a transsphenoidal approach using image guidance techniques to avoid major neurovascular complications.

A Novel Method to Locate Intracranial Anatomic Landmarks of Sella Using Three-Dimensional Computed Tomography Reconstruction Images for Endoscopic Endonasal Transsphenoidal Surgery

OBJECTIVE

To help surgeons to locate the intracranial anatomic landmarks when performing endoscopic endonasal tanssphenoidal surgery using measurements based on three-dimensional computed tomography (CT) reconstruction images.

METHOD

High-resolution axial CT images at the thickness of 0.6 mm, and reconstructed 0.41-mm-thick gapless sagittal and coronal CT images were taken from 111 subjects. Using mimics software, first located the points of nasal spine, midpoint of the posterior hard palate and the basic line between them. Then located the medial edge of foramen lacerums, optic canals, midpoints of tuberculum sellae and posterior-inferior sellar floor, measured their distances to nasal spine and angles between the line connecting these structures to nasal spine and the basic line.

RESULTS

The mean distance from nasal spine to optic canal is 73.12 ± 4.10 mm, and the corresponding angle is 39.79° ± 3.13°. The distance from the medial edge of foramen lacerum to nasal spine is 79.91 ± 4.01 mm, and the corresponding angle is 23.27° ± 2.89°. The distances from midpoints of the tuberculum sellae and posterior-inferior sellar floor to nasal spine are 76.16 ± 4.56 mm and 82.05 ± 4.81 mm, and the corresponding angles are 34.97° ± 3.24° and 26.39° ± 3.51°, respectively. The distances between both foramen lacerums and optic canals are 22.54 ± 3.25 and 23.44 ± 3.49 mm, respectively. The distance from the midpoint of tuberculum sellae to posterior-inferior sellar floor is 13.33 ± 1.87 mm.

CONCLUSION

The current study provides information about intracranial anatomic landmarks, which can help neurosurgeons to locate them and avoid relative complications during endoscopic endonasal transsphenoid surgery. The measurements can be used as surgical indicators to investigate these anatomic landmarks.

Critical analysis of anatomical landmarks within the sphenoid sinus for transsphenoidal surgery

The transsphenoidal approach to the sellar region has been introduced more than a 100 years ago. It is the accepted standard operative corridor to pathologies of the pituitary gland and surrounding structures. There are anatomical landmarks within the sphenoid sinus that are used for orientation directing to the sella floor or the cavernous sinus. Yet, little data can be found on the consistency of these landmarks. It is the aim of this study to evaluate the reliability of these anatomical landmarks for the surgeon's orientation. A total of 245 computed tomography (CT) volume data sets of the cranium performed according to a standardized protocol were analyzed for study purposes. CT scans of the cranium of 125 patients admitted to the emergency room of our hospital receiving a trauma spiral according to the local protocol were employed as a control group when no pathology in the sellar region was observed. In addition, preoperative CT scans of a group of 120 patients diagnosed with pituitary adenomas between 2009 and 2013 were analyzed. Image analysis of the anatomical landmarks included the minimal intercarotid distance (ICD), diameter of the sphenoid sinus (DSS), direction of the septum sinuum sphenoidalium (SSS), and the distance between vomer and clivus (VCD). The overall mean ICD was 16.2 mm, with patients suffering from adenomas showing a mean ICD of 15.8 mm compared with an average 16.5 mm in the control group. DSS was equal for both groups (adenoma group: mean 31.5 mm; controls: mean 31.3 mm). Mean VCD was 27.9 mm in patients with pituitary adenomas compared with 26.7 mm in controls. A septum of the sphenoid sinus located in the midline was found in overall 23 % only. SSS was directed into the bony shield of the internal carotid artery in 28 % of underlying tumors and in 37 % of the control group. This is the first detailed description of landmarks of the sphenoid sinus based on a large radiologic-anatomical analysis of CT scans yielding a wide variation and high inconsistency of these landmarks. From out data, we suggest that the surgeon approaching the sphenoid sinus should handle the anatomical landmarks with care bearing their inconsistency in mind. A thorough planning of the procedure up front is highly recommended. Usage of a navigation system considering the bony structures might as well facilitate as steady the approach to the sellar region in some cases for the patient's sake.

Significant improvement of intractable headache after transsphenoidal surgery in patients with pituitary adenomas; preoperative neuroradiological evaluation and intraoperative intrasellar pressure measurement

OBJECT

Headache is the most common symptom of both primary and metastatic brain tumor, and is generally considered the primary symptom in patients with large pituitary adenomas. However, patients with small pituitary adenomas rarely complain of intractable headache, and neurosurgeons are unsure whether such small adenomas actually contribute to headache. If conventional medical treatments for headache prove ineffective, surgical removal of the adenoma can be considered as an alternative management strategy.

METHODS

We conducted a retrospective review of 180 patients who underwent transsphenoidal surgery (TSS) for pituitary adenomas at Kanazawa University Hospital between 2006 and 2014. Patients with acute phase intratumoral hemorrhage were excluded. We identified nine patients with intractable headache as the chief complaint associated with small pituitary adenoma (diameters 15.8 ± 2.6 mm, 11-20 mm), non-functioning in eight, and prolactin-secreting in one. The preoperative neuroradiological studies and headache characteristics were assessed retrospectively, and the intrasellar pressure evaluation was performed during TSS in the last seven patients.

RESULTS

All nine patients had complete or substantial resolution of their formerly intractable headache after TSS. Headaches consisted of ocular pain ipsilateral to the adenoma localization within the sella in four cases and bifrontal headache in five. Magnetic resonance imaging of these patients revealed small diaphragmatic foramen, which were so narrow that only the pituitary stalk could pass. Computed tomography scans showed ossification beneath the sellar floor in the sphenoid sinus, presellar type in six cases, and choncal type in three. The adenomas included cysts in seven cases. There was no cavernous sinus invasion. Intrasellar pressure measurements averaged 41.5 ± 8.5 mmHg, range 34-59, significantly higher than in control patients without headache (n = 12), namely 22.2 ± 10.6 mmHg (16-30).

CONCLUSION

In this study, the authors demonstrated the validity of TSS in the treatment of intractable headache associated with pituitary adenoma. The presence of ocular pain, especially ipsilateral to the adenoma, integrity of the diaphragm sella, and ossification in the sphenoid sinus, cyst or hemorrhage and the absence of cavernous sinus invasion were the indications for TSS for patients complaining of intractable headache and having pituitary adenomas.

Current imaging techniques for the diagnosis of pituitary adenoma

Stepwise improvements in the imaging of pituitary adenomas in the last 100 years have had a tremendous impact on patient care. Pituitary tumors are now diagnosed earlier in the time course of the disease, improving chances of endocrine and visual recovery. There is improved pre-surgical planning due to a better understanding of the investment of the tumor around important surrounding parasellar structures. Approaches to tumors are now safer due to stereotactic navigation and residual disease can be radiographically followed for a lifetime and treated prior to irreversible neurological damage. Furthermore, adjuvant radiotherapy can be more precisely delivered to the tumor bed with the aid of higher resolution images. Thanks to these incremental improvements previously formidable macroadenomas, which carried a high risk for morbidity and residual disease, can now be treated safely and effectively. Here, we review modern imaging modalities used to diagnose pituitary adenomas, and identify areas for further improvement.

Morphometric analysis of the medial opticocarotid recess and its anatomical relations relevant to the transsphenoidal endoscopic endonasal approaches

BACKGROUND

The medial opticocarotid recess (MOCR) is located in the posterior wall of the sphenoid sinus, medial to the junction of the optic canal (OC) and the carotid prominence (CP). There is controversy in the literature in relation to the presence of the MOCR and its constancy, which is relevant when approaching the skull base through an endoscopic route.

METHODS

The morphometric relations of the MOCR with the surrounding structures were studied in 18 cadaveric specimens after endoscopic endonasal approach (EEA).

RESULTS

The distance between both MOCR was 11.06 ± 1.14 mm; the distance between the MOCR and the lateral opticocarotid (LOCR) recess was 5.56 ± 0.85 mm; the distance between the MOCR and the suprasellar recess was 3.72 ± 0.49 mm; the angle between the MOCR plane and the OC 13.32 ± 2.30°; the angle between the MOCR plane and the CP 13.50 ± 2.68° and; the angle between the OC and the CP 26.81 ± 4.26°. All measurements showed low variability, with low standard deviation and interquartile range. No relations were found between any of the measurements.

CONCLUSIONS

The MOCR may be used as a reference point for precise location of structures during EEA. Objective measurements may be especially useful in cases with distorted sphenoid bone anatomy.

Endoscopic endonasal transsphenoidal surgery: implementation of an operative and perioperative checklist

Endoscopic endonasal surgery relies heavily on specialized operative instrumentation and optimization of endocrinological and other critical adjunctive intraoperative factors. Several studies and worldwide initiatives have previously established that intraoperative and perioperative surgical checklists can minimize the incidence of and prevent adverse events. The aim of this article was to outline some of the most common considerations in the perioperative and intraoperative preparation for endoscopic endonasal transsphenoidal surgery. The authors implemented and prospectively evaluated a customized checklist at their institution in 25 endoscopic endonasal operations for a variety of sellar and skull base pathological entities. Although no major errors were detected, near misses pertaining primarily to missing components of surgical equipment or instruments were identified in 9 cases (36%). The considerations in the checklist provided in this article can serve as a basic template for further customization by centers performing endoscopic endonasal surgery, where their application may reduce the incidence of adverse or preventable errors associated with surgical treatment of sellar and skull base lesions.

Clinicopathological correlates of extrasellar growth patterns in pituitary adenomas

We reviewed clinical, imaging and histopathology details of 297 patients who underwent surgery for pituitary adenomas, with an equal distribution of functional and non-functioning tumors, to examine clinicopathological correlates of extrasellar growth. Knosp grades of 3 and 4 on MRI defined cavernous sinus invasion, Hardy grades of C and D defined significant suprasellar/subfrontal extension, and intraoperative evidence of tumor eroding through the clivus or sellar floor defined infrasellar invasion. Disease status at follow-up was known in 246 patients overall, including 35 patients who were evaluated for progression of residual disease on serial imaging. On univariate analysis, we found several statistically significant associations (p < 0.05) including adenoma size with age, sex and tumor protein p53 reactivity; cavernous sinus invasion with size, non-functional status, increased mitotic activity, an elevated MIB-1 proliferation index and p53 reactivity; suprasellar/subfrontal extension with p53 reactivity; and infrasellar invasion with age and tumor size. When adjusting for confounders with logistic regression, several significant associations were evident including adenoma size with male sex and p53 reactivity; cavernous sinus invasion with size and elevated MIB-1 proliferation index; suprasellar/subfrontal extension with p53 reactivity; and infrasellar invasion with adenoma size alone. Patients with early progression of postoperative residual tumor were younger with a non-significant trend towards higher MIB-1 proliferation indices. Individual patterns of extrasellar growth in pituitary adenomas are associated with unique clinical and immunohistochemical profiles. Younger patients with elevated MIB-1 values are probably at high risk for early recurrence of non-functioning tumors. Definitions of atypia must be standardized before more robust assumptions about tumor biology can be established.