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

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.

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.

Intraoperative Ultrasonography in Pituitary Surgery Revisited: An Institutional Experience and Systematic Review on Applications and Considerations

OBJECTIVE

The primary objective of this systematic review is to evaluate the effectiveness of intraoperative ultrasound (IOUS) in improving outcomes in patients undergoing pituitary surgery.

METHODS

A systematic review was performed by searching MEDLINE (PubMed), Web of Science, Scopus, and Embase electronic bibliographic databases from conception to 2022.

RESULTS

The included studies yielded a total of 660 patients, with 488 patients undergoing IOUS. Outcome were available for 341 patients treated with IOUS and 157 patients who were treated without the IOUS application, and the remission rates following surgery were 76% and 59%, respectively. Only 2 studies reported remission rates for both groups, and meta-analysis for these studies showed significant superiority of intraoperative ultrasonography (Random effect, odds ratio 4.99, P < 0.01). Regarding extent of resection, IOUS resulted in 71% gross total resection, while absence of IOUS yielded a gross total resection rate of 44%. Among studies with available follow-up on IOUS, the recurrence rate was 3%. Pituitary dysfunction (34%), cerebrospinal fluid leak (31%), and central nervous system infection (8%) were the most common complications in the IOUS group. The mean follow-up was 19.97 months in studies reporting follow-up time.

CONCLUSIONS

The application of the IOUS is both safe and effective and could improve the outcome of pituitary surgeries. IOUS can assist surgeons in the identification of pituitary tumors and their surrounding anatomy and can help minimize the risk of complications associated with this complex surgical procedure.

Change in the Location of the Optic Strut Relative to the Anterior Clinoid Process Pneumatization

OBJECTIVE

This study aimed to peruse the alteration of the position of the optic strut (OS) according to the anterior clinoid process (ACP) pneumatization.

METHODS

This retrospective study conducted on cone-beam computed tomography images of 400 patients with a mean age of 36.49±15.91 years.

RESULTS

Anterior clinoid process length, width, and angle were measured as 10.56±2.42 mm, 5.46±1.31 mm, and 42.56±14.68 degrees, respectively. The tip of ACP was measured as 6.60±1.50 mm away from the posterior rim of OS. In the 631 sides (78.87%) did not have ACP pneumatization. In the cases with ACP pneumatization, three different configurations were identified as follows: Type 1 in 71 sides (8.87%), Type 2 in 56 sides (7%), and Type 3 in 42 sides (5.23%). Relative to ACP, the location of OS was determined as follows: Type A in 29 sides (3.64%), Type B in 105 sides (13.12%), Type C in 344 sides (43%), Type D in 289 sides (36.12%), and Type E in 33 sides (4.12%). The spread of data related to the attachment site of OS according to the presence or absence of ACP pneumatization showed that the location of OS was affected by ACP pneumatization (P<0.001). In ACPs with pneumatization, the frequency of OS position relative to ACP was found as follows: Type A in none of sides (0%), Type B in 8 sides (7.6%), Type C in 53 sides (15.4%), Type D in 88 sides (30.4%), and Type E in 20 sides (60.6%).

CONCLUSIONS

The main finding of this study was that the location of OS relative to ACP was affected by ACP pneumatization. In ACPs with pneumatization, OS was located more posteriorly compared with ACPs without pneumatization.

Evaluation of the Cranial Aperture of the Optic Canal on Cone-Beam Computed Tomography Images and its Clinical Implications for the Transcranial Approaches

OBJECTIVE

This study aimed to investigate morphometric properties of the cranial aperture (CA) of the optic canal.

METHODS

Cone-beam computed tomography images of 400 individuals (200 males and 200 females) aged 37.32 ± 15.87 years were retrospectively examined to assess the morphometry and morphology of the CA.

RESULTS

The height and width of CA were found as 4.22 ± 0.74 mm and 7.27 ± 1.15 mm, respectively. The distances between the CA and the midsagittal line, the anterior and lateral boundaries of the anterior skull base were measured as 5.77 ± 1.32 mm, 64.97 ± 6.36 mm, and 41.00 ± 4.05, respectively. The angle of the optic canal in the sagittal plane was measured as 7.57° ± 3.95°, whereas in the horizontal plane as 38.96° ± 4.36°. The aperture shape was defined as the tear-drop (413 foramina, 51.62%), triangular (180 foramina, 22.50%), oval (158 foramina, 19.75%), round (30 foramina, 3.75%), and polygonal (19 foramina, 2.38%).

CONCLUSIONS

The authors observed that the diameters, and angulations of the CA may change relative to gender and the shape. The anatomic features of CA are important for the positioning of the patient's head, the choice of the appropriate surgical approach or equipment, and the detection of anatomical landmarks during interventions. In this context, our dataset may be beneficial for surgeons helpful as a reference for radiological evaluations.

Extended Neuroendoscopic Endonasal Approach for Resection of Craniopharyngioma in Children

Objective

To explore the surgical approach and technique of neuroendoscopic endonasal resection of pediatric craniopharyngiomas and to further evaluate its safety and effect in children.

Methods

The clinical data of 8 children with craniopharyngiomas who were surgically treated by neuroendoscopy through an extended endonasal approach in our center from 2018 to 2021 were retrospectively analyzed. The related surgical approach and technique were evaluated to improve the surgical results and further reduce the surgical complications when removing craniopharyngioma in children.

Results

All 8 patients achieved a gross-total resection of the tumor under neuroendoscopy. Postoperatively, 2 cases of transient hyperthermia and 4 cases of transient hyper- and/or hyponatremia occurred within the first 2 weeks, all of which were quickly controlled. Seven patients had symptoms of diabetes insipidus to varying degrees after the operation, and 4 of them improved within 1–3 months after surgery, but 3 cases still needed oral pituitrin. There were no cases of coma or death, leakage of cerebrospinal fluid, or severe electrolyte imbalance after surgery. During the postoperative follow-up of 3 months to 2 years, no tumor recurrence was found. Among the 7 patients who suffered postoperative neuroendocrine deficiencies, 3 patients were found to be temporary during the follow-up, but 4 patients still required hormone replacement therapy. Particularly, postoperative visual deterioration and olfactory defect that occurred in patients were all improved during follow-up periods. In addition, 4 cases of obesity were noted at the last follow-up.

Conclusions

Extended neuroendoscopic endonasal resection of craniopharyngiomas may be used as a safe and effective approach for children. Due to the poor pneumatization of the sphenoid sinus and worse compliance of treatment in children, surgical techniques of exposing the sellar region, removing the tumor, and reconstructing the skull base, as well as postoperative management of patients was proposed. However, due to the limited surgical cases in the study, the surgical safety and effects of the extended neuroendoscopic endonasal approach for children with craniopharyngiomas need to be further studied in the future.

Chiasmatic Ridge: Incidence, Classification, and Clinical Implications

OBJECTIVE

The study aimed to identify the chiasmatic ridge (CR) morphology and to discuss its surgical significance.

METHODS

The suprasellar region of 90 adult dry skulls with unknown ages, sexes, or nationalities was examined to record the shape and incidence of the CR.

RESULTS

The CR was found in 14 (15.56%) of 90 dry skulls. The ridge was classified into 3 types, taking into account its shape, incidence (presence/absence), and the risk of residual tumor formation. The absence of the CR was named as Type 1 (76 cases, 84.44%). The bony extension without a hidden area was identified as Type 2 (8 cases, 8.89%), while the bony extension with a hidden area as Type 3 (6 cases, 6.67%).

CONCLUSION

Type 3 CR (which has an evident hidden area beneath the ridge) should be taken into account by neurosurgeons to eliminate possible residual tumor risk during removal of tumors (eg, meningioma) with subfrontal or supraorbital approaches.

Anatomic features of the cranial aperture of the optic canal in children: a radiologic study

OBJECTIVE

This study aimed to peruse anatomic features of the cranial aperture of the optic canal (CAOC) for obtaining an extended morphometric dataset in children.

METHODS

Computed tomography images of 200 children were included in this retrospective work to analyze the shape, location and diameters of the CAOC.

RESULTS

The CAOC area, width and height were observed as 17.53 ± 2.80 mm², 6.12 ± 0.84 mm, and 4.35 ± 0.64 mm, respectively. The angle of the optic canal in axial plane was found as 39.28 ± 5.13°, while in sagittal plane as 16.01 ± 6.76°. The distance between the CAOC and the midsagittal line was 7.17 ± 1.48 mm. The CAOC was measured as 54.04 ± 5.23 mm and 42.55 ± 3.28 mm away from the anterior and lateral boundary of the anterior skull base, respectively. The CAOC shape was described as the tear-drop (186 foramina, 46.5%), triangular (156 foramina, 39%), oval (47 foramina, 11.8%), and round (11 foramina, 2.8%).

CONCLUSION

The depth, angle and diameter measurements belonging to the CAOC were changing according to its shape or demographic data (e.g., sex and age). Therefore, preoperative radiologic evaluation containing the shape, location and size of the CAOC should be considered by multidisciplinary operating teams in terms of surgical interventions such as implant positioning.

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.

Preoperative Computed Tomography Imaging of the Sphenoid Sinus: Striving Towards Safe Transsphenoidal Surgery

Introduction  Preoperative high-resolution computed tomography (HRCT) is essential in patients undergoing transsphenoidal surgery to identify potential high-risk anatomic variations. There is no consensus in the literature, as to which grading system to use to describe these variants, leading to inconsistent terminology between studies. In addition, substantial variability exists in the reported incidence of anatomic variants. In this study, we performed an institutional imaging analysis and literature review with the objective of consolidating and clearly defining these sphenoid sinus anatomical variations. In addition, we highlighted their surgical implications and propose a checklist for a systematic assessment of the sphenoid sinus on preoperative CT. Methods  Review of the literature and retrospective analysis assessing several imaging parameters in 81 patients who underwent preoperative HRCT imaging for endoscopic transsphenoidal tumor resection from January 2008 through July 2015 at Rush University Medical Center. Results  The most common sphenoid pneumatization patterns were sellar (45%) and postsellar (49%) types. Anterior clinoid process (ACP) pneumatization was seen in 17% of patients with high concordance of ipsilateral optic nerve (ON) protrusion. ON protrusion and dehiscence was present in 17 and 6% of patients, respectively. Internal carotid artery (ICA) protrusion and dehiscence was present in 30 and 5% of patients, respectively. Dehiscence rates from local bone invasion overlying the ICA and ON occurred in 17 and 4% of cases, respectively. Conclusions  Our study highlights and reviews the key variants that have potential to impact surgical complications and outcomes in a heterogeneous patient population. The proposed preoperative CT checklist for patients, undergoing transsphenoidal surgery, consistently identifies these higher risk anatomical variants.

A Computed Tomography Study of the Prechiasmatic Sulcus Anatomy in Children

PURPOSE

To investigate the characteristics of the prechiasmatic sulcus in children aged between 1-20 years.

METHODS

Patient files of 200 children admitted to the university hospital on 2019 were analyzed, retrospectively. The computed tomography images of patients were used to obtain anatomical knowledge containing prechiasmatic sulcus types and dimensions.

RESULTS

The measurements related to the sulcal length (6.94 ± 1.25 mm) and sulcal angle (31.01 ± 18.13°) showed that the sulcal length did not alter in children between 1 and 20 years, whereas the sulcal angle did not vary from infancy to prepubescent period, but it was decreasing in postpubescent period. In 29 patients, the sulcal length was observed to divide into 2 parts with an evident angle. The interoptic distance and planum length were found as follows: 14.70 ± 2.85 mm and 14.84 ± 4.12 mm, respectively. The order of PS types was observed as type 4 (26.5%, 53 cases) > type 2 (26%, 52 cases) > type 1 (24%, 48 cases) > type 3 (23.5%, 47 cases).

CONCLUSIONS

The sulcal length did not vary in children, whereas the sulcal angle decreased with an irregular pattern. The sulcal angle decreased after prepubescent period, possibly due to the sphenoid sinus pneumatization and spheno-occipital synchondrosis. The sulcal length angle mostly in infants and young children may cause surgical orientation difficult during the resection of tumors using transcranial approaches.

Application of the Three Points and Three Lines Method to Accurately Open the Sellar Floor in Microscopic Transsphenoidal Surgery of Pituitary Adenomas

OBJECTIVE

In this study, the sellar floor morphology of patients with pituitary adenoma is analyzed and a simple yet reliable method is identified to determine the location of bone window opening.

METHODS

Clinical information of 144 consecutively admitted patients was retrospectively analyzed. Enhanced magnetic resonance imaging of the midsagittal plane was selected as the reference for classifying the sellar floor. Intraoperative tumor location, extent of tumor resection, and follow-up results were analyzed for different types of sellar floor. The tuberculum sellae, lowest point of the sphenoid sinus, and the lowest point of the sellar floor and 3 lines related to them were used to classify the sellar floor. This is referred to as the "three points and three lines" method.

RESULTS

Based on its location in the sphenoid sinus, the sellar floor can be classified into 4 types: 12 patients (8.3%) with high sellar, 70 (48.6%) with medium sellar, 30 (20.8%) with low sellar, and 32 (22.8%) with steep sellar. The maximum tumor diameter, maximum sellar floor diameter, and the intercarotid distance were all significantly different among patients with different types of sellar floor (P < 0.001). For all patients, quick intraoperative location of the sellar floor opening was achieved. A total of 104 patients (72.2%) had total tumor resection, 28 (19.40%) had subtotal tumor resection, and 4 (2.8%) had partial tumor resection. Twenty patients (13.9%) experienced cerebrospinal fluid leak, and there was no significant difference in cerebrospinal fluid leak rate among groups.

CONCLUSIONS

Presurgical classification and location of the sellar floor are critical for understanding and assessing the transsphenoidal approach. Different types of sellar floor appeared in the surgery with different morphologic features. The three points and three lines method helps the surgeon to predetermine the location of the sellar floor opening and to shorten surgical time.

Fetal Anatomy of the Optic Strut and Prechiasmatic Sulcus with a Clinical Perspective

OBJECTIVE

The main objective of the study was to show the morphologic features of optic strut (OS) and prechiasmatic sulcus (PS) in the fetal skull base with a surgical anatomical perspective.

METHODS

Twenty-three fetal cadavers (9 female, 14 male) with an average age of 21.70 ± 3.12 (range: 16-28) weeks of gestation in the inventory of the Anatomy Department were included in the study. Measurements were made with a digital image analysis software and goniometer.

RESULTS

The sulcal length, interoptic distance, planum length, and sulcal angle were detected as follows: 3.91 ± 0.74 mm, 6.88 ± 1.04 mm, 6.55 ± 1.51 mm, and 24.52 ± 9.51°, respectively. Considering the location of the posteromedial margin of OS according to PS, OS was identified as the sulcal in 56.5% (13 cases), postsulcal in 30.4% (7 cases), and asymmetric in 13% (3 cases). According to the sulcal length and angle, PS was identified as type 1 in 26.1% (6 cases), type 2 in 21.7% (5 cases), type 3 in 30.4% (7 cases), and type 4 in 21.7% (5 cases).

CONCLUSIONS

Our findings suggest that the sulcal length and angle reach adult size in utero. Taking into account the fetal and the gathered adult measurements, the high percentage of steep angle compared to flat angle show that after birth, PS become more flat, probably depending on the variations of the sphenoid sinus pneumatization. Thus, more studies conducted on the alterations in PS and OS types relative to the pneumatization are needed in terms of patient positioning, selection of appropriate surgical approach, and intraoperative decision-making.

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.

Lack of Sphenoid Pneumatization Does Not Affect Endoscopic Endonasal Pediatric Skull Base Surgery Outcomes

OBJECTIVES/HYPOTHESIS

Currently, due to the rarity of pathology, there are limited data surrounding outcomes of pediatric skull base surgery. Traditionally, surgeons have proceeded with caution when electing endonasal endoscopic transsellar/transplanum approaches to the skull base in pediatric patients due to poor sphenoid pneumatization. In this study, we review outcomes of endoscopic pediatric skull base surgery based on sphenoid pneumatization patterns.

STUDY DESIGN

Retrospective chart review.

METHODS

A review of all cases of pediatric (age < 18 years) craniopharyngioma managed via an endoscopic endonasal approach at a tertiary academic medical center.

RESULTS

A total of 27 patients were included in the analysis. The median age was 8 years. Nineteen (70%) patients were male. Presellar, sellar/postsellar, and conchal sphenoid pneumatizations were found in 6, 11, and 10 patients, respectively. There was no significant association between sphenoid pneumatization pattern and extent of resection (gross vs. subtotal, P = .414), postoperative cerebrospinal fluid (CSF) leak (P = .450), intraoperative estimated blood loss (P = .098), total operative time (P = .540), and length of stay (P = .336). On multivariate analysis, after accounting for age, sex, preoperative cranial nerve involvement, and cavernous sinus invasion, there remained no significant association between sphenoid pneumatization pattern and extent of resection (P = .999) and postoperative CSF leak (P = .959).

CONCLUSIONS

Sphenoid pneumatization pattern does not appear to affect outcomes in endoscopic skull base surgery in the pediatric population. Importantly, lack of sphenoid pneumatization does not impede gross total resection or increase complications. Thorough knowledge of the anatomy during the endoscopic approach is critical to optimize outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:832-836, 2019.

Radiological "Teddy Bear" Sign on CT Imaging to Aid Internal Carotid Artery Localization in Transsphenoidal Pituitary and Anterior Skull Base Surgery

Objectives  Internal carotid artery (ICA) injury remains a rare but potentially fatal complication of transsphenoidal pituitary or anterior skull base surgery. Preoperative imaging must be scrutinized to minimize risk. On axial computed tomography (CT), the protrusions of the ICAs into the sphenoid resemble a "teddy bear." This article aims to describe the sign, its grading system (0-2) and quantify its presence. Design  Retrospective review of preoperative CT imaging. Setting  Tertiary referral center in the United Kingdom. Participants  One hundred patients who underwent endoscopic transsphenoidal surgery for pituitary disease were enrolled. Main Outcome Measure  The presence and grading of the "teddy bear" sign were assessed on preoperative CT imaging. Results  A grade 2 (strongly positive) "teddy bear" sign was identified in 40% at the level of the superior pituitary fossa, 78% at the inferior pituitary fossa, and 59% at the clivus. A grade 1 (intermediate) sign was seen in 23.5, 7.5, and 10% of cases, respectively. In 5% of cases, the sign was grade 0 at all levels-indicating poor intraoperative localization of the ICA. Conclusion  The "teddy bear" sign is a useful preoperative tool for identification of anatomy predisposing patients to a higher risk of ICA injury. Those patients who have an absent or grade 0 "teddy bear" sign require extra care to ensure intraoperative localization of the ICAs which may include the use of neuronavigation or a Doppler probe. A grade 2 sign predicts good intraoperative localization of the ICA intraoperatively to inform the safe lateral limit of sellar bone resection.