Medial Wall Of Cavernous Sinus Research Articles

Endoscopic endonasal approach for MRI–Negative Cushing’s microadenoma

A 54-year-old male with a history of diabetes mellitus type 2 for 12 years and hypertension was seen in the clinic due to poorly controlled diabetes. Inferior petrosal sinus sampling (IPSS) confirmed Cushing’s disease with primary adrenocorticotropic hormone (ACTH)–secreting pituitary adenoma on the right. However, 3T and subsequent 7T MRI showed no visible tumor. An endoscopic transsphenoidal approach was selected to explore the pituitary gland and resect the presumed microadenoma. Tumor was identified in the lateral recess along the right medial cavernous sinus wall and gross-total resection (GTR) was performed. The normal pituitary gland was preserved, and the patient went into remission. The video can be found here: https://stream.cadmore.media/r10.3171/2023.4.FOCVID2324

Resection of the Cavernous Sinus Medial Wall Improves Remission Rate in Functioning Pituitary Tumors: Retrospective Analysis of 248 Consecutive Cases.

The purpose of transsphenoidal surgery (TSS) for a functioning pituitary tumor (FPT) is to achieve endocrinological remission. The biggest challenge is aggressive tumor resection invading the cavernous sinus (CS). To evaluate the effects of the medial wall of CS (MWCS) resection during FPT surgery. Consecutive FPTs were reviewed for CS invasion (CSI) between April 2018 and December 2021. We operated on more than 250 FPTs, including 134 somatotroph tumors, 70 corticotroph tumors, 35 lactotroph tumors, and 9 thyrotroph tumors. The patients were classified into 3 groups based on the relationship between the tumor and the CS: group A (no clear wall invasion), in which MWCS was not removed because of no tumorous direct contact with MWCS (N = 92) and group B (possible wall invasion), where MWCS was removed because we were not confident of MWCS invasion (N = 102). Among these 102 patients, histological tumor invasion was confirmed in 45 of 79 patients (57%) for whom histology findings were available. Tumors invading the CS clearly during surgery were classified into the "clear CS invasion" (group C: N = 55) group. The overall complete remission rate in group B was 94%, which was as high as that in group A (87%). Moreover, we clarified that microscopic invasion of MWCS could not always be predicted from Knosp grading. MWCS invasion occurred in 57% of cases confirmed histologically where it was unclear during surgery, and its resection can improve the overall complete remission rate in FPT cases.

The endonasal midline inferior intercavernous approach to the cavernous sinus: technical note, cadaveric step-by-step illustration, and case presentation.

Traditional endoscopic endonasal approaches to the cavernous sinus (CS) open the anterior CS wall just medial to the internal carotid artery (ICA), posing risk of vascular injury. This work describes a potentially safer midline sellar entry point for accessing the CS utilizing its connection with the inferior intercavernous sinus (IICS) when anatomically present. The technique for the midline intercavernous dural access is described and depicted with cadaveric dissections and a clinical case. An endoscopic endonasal approach exposed the periosteal dural layer of anterior sella and CS. The IICS was opened sharply in midline through its periosteal layer. The feather knife was inserted and advanced laterally within the IICS toward the anterior CS wall, thereby gradually incising the periosteal layer of the IICS. The knife was turned superiorly then inferiorly in a vertical direction to open the anterior CS wall. This provided excellent access to the CS compartments, maintained the meningeal layer of the IICS and the medial CS wall, and avoided an initial dural incision immediately adjacent to the ICA. The midline intercavernous dural access to the CS assisted by a 90° dissector-blade is an effective modification to previously described techniques, with potentially lower risk to the ICA.

Endoscopic Transsphenoidal Surgery of Microprolactinomas: A Reappraisal of Cure Rate Based on Radiological Criteria.

Current standard treatment of microprolactinomas is dopamine agonist therapy. As this drug treatment is lifelong in up to 80% of cases, many patients consult pituitary surgeons regarding a surgical alternative. To identify prognostic criteria for surgical remission, we reviewed outcomes of our series of microprolactinomas treated with endoscopic transsphenoidal surgery, with a special emphasis on magnetic resonance adenoma delineation and position. Our study cohort comprises a single center series of 60 patients operated for histopathologically verified magnetic resonance imaging unequivocally identifiable endosellar microprolactinoma between 2003 and 2017. In 31 patients the adenoma was enclosed by pituitary gland (group ENC), in 29 patients the adenoma was located lateral to the gland adherent to the medial cavernous sinus wall (group LAT). After a mean follow-up of 37 mo (range 4-143 mo), remission rate was significantly higher in adenomas enclosed by pituitary gland (group ENC) than adenomas located lateral to the gland (group LAT), with 87% vs 45%, P=.01. Intraoperatively, 4 patients showed signs of invasiveness. Preoperative prolactin levels did not differ between the groups (mean 155 and 187 ng/ml in group ENC and LAT, respectively).A binary logistic regression model revealed that only the radiological criteria applied showed a significant correlation (P=.003) with endocrine remission. According to our results, remission rate is significantly higher in microprolactinomas enclosed by the pituitary gland. However, the decision for surgery should take into account surgeons experience and possibility of complications.

Morphological aspect of the superior wall of the cavernous sinus

The lateral wall of cavernous sinus (CS) is made of two distinct layers of dura: meningeal dura (the external one) and endosteal dura (internal one). On the other hand, some debates about the histomorphological aspects of the superior and medial wall of CS are present in literature (1-2). In this study we aimed to demonstrate the histomorphological features of the superior wall of CS during cadaver dissection studies. We considered only the sellar area, bounded anteriorly by the posterior margin of planum sphenoidale, antero-inferiorly by the antero-superior surface of sphenoid sinus, inferiorly by the superior surface of sphenoid sinus, posteriorly by dorsum sellae, laterally by the interclinoid ligament (preserving the medial wall of CS) and superiorly by diaphragma sellae. The samples were collected, decalcified, paraffin embedded and serial sections were finally processed for standard histomorphological staining. Sections of each sample were analyzed using optical light microscope equipped with a digital camera. Our results showed that the two layers separated themselves at the superior wall of CS: the meningeal layer continued as diaphragma sellae and the endosteal layer continued downward between the venous compartment and pituitary capsule. In addition, between these two layers it was possible to define an interdural pathway. These data should be considered in the evaluation of the rare, though possible, extension of pituitary adenomas in the interdural space, rather than into the cavernous sinus.

Surgical outcomes using a medial-to-lateral endonasal endoscopic approach to pituitary adenomas invading the cavernous sinus

This study details the extent of resection and complications associated with endonasal endoscopic surgery for pituitary tumors invading the cavernous sinus (CS) using a moderately aggressive approach to maximize extent of resection through the medial CS wall while minimizing the risk of cranial neuropathy and blood loss. Tumor in the medial CS was aggressively pursued while tumor in the lateral CS was debulked in preparation for radiosurgery. A prospective surgical database of consecutive endonasal pituitary surgeries with verified CS invasion on intraoperative visual inspection was reviewed. The extent of resection as a whole and within the CS was assessed by an independent neuroradiologist using pre- and postoperative Knosp-Steiner (KS) categorization and volumetrics of the respective MR images. The extent of resection and clinical outcomes were compared for medial (KS 1-2) and lateral (KS 3-4) lesions. Thirty-six consecutive patients with pituitary adenomas involving the CS who had surgery via an endonasal endoscopic approach were identified. The extent of resection was 84.6% for KS 1-2 and 66.6% for KS 3-4 (p = 0.04). The rate of gross-total resection was 53.8% for KS 1-2 and 8.7% for KS 3-4 (p = 0.0006). Six patients (16.7%) had preoperative cranial neuropathies, and all 6 had subjective improvement after surgery. Surgical complications included 2 transient postoperative cranial neuropathies (5.6%), 1 postoperative CSF leak (2.8%), 1 reoperation for mucocele (2.8%), and 1 infection (2.8%). The endoscopic endonasal "medial-to-lateral" approach permits safe debulking of tumors in the medial and lateral CS. Although rates of gross-total resection are moderate, particularly in the lateral CS, the risk of permanent cranial neuropathy is extremely low and there is a high chance of improvement of preexisting deficits. This approach can also facilitate targeting for postoperative radiosurgery.

Medial wall of the cavernous sinus: dural or fibrous layer?

To the Editor: I read with great interest the article by Goncalves et al. “Cavernous sinus medial wall: dural or fibrous layer? Systematic review of the literature” [4], recently published in your journal. As the authors of this article found a variation among several studies without conclusive answer to their research question, I would like to provide some comments on their study and highlight a possible explanation for their results. Goncalves et al. conducted a systematic literature review to find out the microanatomy of the medial wall of the cavernous sinus (CS) and its clinical importance on sellar pathologies. Based on 14 experimental studies, four studies found that the medial wall of the CS is composed of a loose, fibrous structure, and according to ten studies, medial wall is composed of a dural layer that constitutes the lateral wall of the sella. They explain the variation in the results section by lacking in definition standards and methodological criteria. First, I am grateful for the Goncalves et al. methodology in their article as they support and establish a step toward the concept of evidence-based morphology [1, 3]. The articles based on this concept are still rare in neurosurgical literature, yet available data about the anatomy, especially in the terms of variation, can be obtained from this kind of study. It can also highlight a hidden anatomical problem that can be utilized to refine the neurosurgical approaches seen in Goncalves et al. work and in the comments on their paper. With regard to medial wall of the CS, to make it understandable, I believe it should always be divided into two parts; sphenoidal and sellar. Even though, at the sphenoidal part there is one layer of dura (osteoperiosteal dura) that adheres to the bone and forms the inferomedial wall of the cavernous space. At the sellar part or the superior medial wall, I do not believe that there is any dural layer that belongs to the CS itself or to the CS as an anatomical entity. To clarify this point, and to give an explanation to that type of anatomical variation which Goncalves et al. found in several studies, there are two facts we need to keep in mind; first, the CS is an extradural anatomical entity [5, 6]. The hypophysis compartment is isolated from all surrounding structures by what is called the pituitary bag. A detailed description of the pituitary bag was reported by Francois et al. using electron microscopic-based methodology [2]. Having said that, we can make a more useful conclusion with regard to the medial wall of the CS; there is no dural layer for superior medial wall of the CS itself. The dural layer that have been reported belong to the pituitary bag and was misinterpreted as it belongs to the CS itself according to some studies. Furthermore, this explains the presence of easy surgical cleavage plane between the medial wall and the suprasellar dura (diaphragma sellae) that was reported by Professor Kawase in his comment at the end Goncalves et al. paper.

Value of MRI characteristics of medial wall of cavernous sinus in preoperative assessment of invasive pituitary adenomas

Objective To evaluate the value of MRI characteristics of medial wall of cavernous sinus in preoperative assessment of invasive pituitary adenomas,Methods The MRI scans of 39 pituitary adenomas were obtained with a 3.0 T MRI scanner preoperatively.Special attention was given to the integrity of the medial wall of cavernous sinus,Knosp- Steiner grading scales,relationship between tumor and internal carotid artery and possible infiltration of cavernous sinus.Then all the patients received operations,37 cases through transspheniodal approach and 2 transcranial approach.The dura of sellar floor and tumor tissue were obtained intraoperatively to assess the growth pattern of tumor by histologically verified dural invasion and Ki -67 labeling index( Ki -67 LI),respectively.The surgical and pathological findings were compared with the MRI findings.Results The integrity of the medial wall of cavernous sinus were compared with the surgical findings,the positive predictive value (PPV),negative predictive value (NPV),Youden index and the area under ROC curve to infiltration of the medial wall were 75％,100％,0.952,0.976,respectively,demonstrating good diagnostic value on cavernous sinus invasion (CSI).The kappa value was 0.788,0.732,0.611between the integrity of the medial wall of cavernous sinus and Knosp - Steiner grading scale,relationship between tumor and internal carotid artery and possible infiltration of cavernous sinus,respectively,which revealed consistency among them.Accordingly,the integrity of the medial wall of cavernous sinus was related to the dural invasion of sellar floor and the Ki -67 LI.Conclusions The integrity of the medial wall of cavernous sinus on 3.0 T MRI is an important preoperative predictor of CSI,which will guide the resection schedule and a safer and less invasive access to the lesion located in cavernous sinus. Key words: Cavernous sinus; Medial wall; Pituitary adenomas; Invasion; MRI; Dura; Ki -67 labeling index

Cavernous sinus medial wall: dural or fibrous layer? Systematic review of the literature

The cavernous sinus (CS) has one of the most complex anatomical networks of the skull base and because of the diversity of its contents is involved in many pathological processes. Nevertheless, anatomical literature concerning the CS is still controversial, so a systematic literature review was performed to find out the microanatomy of the medial wall of the CS and its clinical importance on sellar pathologies. Experimental studies from English-language literature between 1996 and 2010 were identified in MEDLINE, LILACS, and Cochrane databases. After analysis, two tables were prepared exhibiting the major points of each article. Fourteen experimental studies were included in the tables. Four studies concluded that the medial wall of the CS is composed of a loose, fibrous structure, and the remaining ten presumed that the medial wall is formed by a dural layer that constitutes the lateral wall of the sella. The lack of definition standards and of methodological criteria led to variation in the results among different studies. Thus, this hindered results comparison, possibly explaining the different observations.

Prospective evaluation of the characteristics and incidence of adenoma-associated dural invasion in Cushing disease

Dural invasion by adrenocorticotropic hormone (ACTH)-secreting adenomas is a significant risk factor for incomplete resection and recurrence in Cushing disease (CD). Since ACTH-producing adenomas are often the smallest of the various types of pituitary tumors at the time of resection, examining their invasion provides the best opportunity to identify the precise sites of early dural invasion by pituitary adenomas. To characterize the incidence and anatomical distribution of dural invasion by ACTH-secreting adenomas, the authors prospectively and systematically analyzed features of dural invasion in patients with CD. The authors prospectively studied consecutive patients with CD undergoing the systematic removal of ACTH-secreting adenoma and histological analysis of the anterior sella dura as well as other sites of dural invasion that were evident at surgery. Clinical, imaging, histological, and operative findings were analyzed. Eighty-seven patients with CD (58 females and 29 males) were included in the study. Overall, dural invasion by an ACTH-positive adenoma was histologically confirmed in 30 patients (34%). Eighteen patients (60% of dural invasion cases, 21% of all patients) had evidence of cavernous sinus wall invasion (4 of these patients also had other contiguous sites of invasion), and 12 patients (40% of dural invasion cases) had invasion of the sella dura excluding the cavernous sinus wall. Eleven patients (13% all patients) had invasion of the routinely procured anterior sella dura specimen. Preoperative MR imaging revealed an adenoma in 64 patients (74%) but accurately predicted dural invasion in only 4 patients (22%) with cavernous sinus invasion and none of the patients with non-cavernous sinus invasion. Adenomas associated with dural invasion (mean ± SD, 10.9 ± 7.8 mm, range 2-37 mm) were significantly larger than those not associated with dural invasion (5.7 ± 2.1 mm, range 2.5-12 mm; p = 0.0006, Mann-Whitney test). Dural invasion by ACTH-producing adenomas preferentially occurs laterally into the wall of the cavernous sinus. Preoperative MR imaging infrequently detects dural invasion, including cavernous sinus invasion. Invasion is directly associated with tumor size. To provide a biochemical cure and avoid recurrence after resection, identification and removal of invaded sella dura, including the medial cavernous sinus wall, are necessary.

B005 Cochlear implantation in very young children

Endoscopic endonasal transplanum and transsellar approaches are frequently utilized to manage pituitary adenomas, craniopharyngiomas, and meningiomas. In addition to the intrinsic panoramic view from the endoscope, wide access using both nostrils and a posterior septectomy can aid in both visualization and complete tumor removal. When necessary, a posterior ethmoidectomy and/or partial middle turbinate resection can be used to improve access. Recognizing key anatomic landmarks from an endonasal viewpoint such as the sella turcica, tuberculum sella, planum sphenoidale, internal carotid arteries, and optic nerves is critical. For sellar surgery, a wide sellar opening can be created from the tuberculum to the sellar floor and laterally to the medial cavernous sinus wall while maintaining the sellar dura. For transplanum approaches, the lateral bony osteotomies parallel the optic canals and are connected to the planum osteotomy that is slightly anterior to the tumor extent. The tuberculum sella can then be removed to expose the sphenoid limbus, a reliable landmark for the optic apparatus. Reconstruction of these skull base defects ranges from simple to complex depending on the size, flow of cerebrospinal fluid (CSF), and degree of intracranial dissection. Vascularized mucoperiosteal flaps like the nasoseptal flap have reduced the rates of postoperative CSF leak. Either early harvest of the nasoseptal flap or preservation of the vascular pedicle is advocated to increase the reconstructive options.

Membranous layers of the pituitary gland and related clinical issues

Objective The purpose of this study was to examine the membranous layers of the human pituitary gland and their relationships with invasive adenomas. Method Histological and microdissection techniques were used to study 8 fetal and 10 adult human cadavers, respectively. The distribution of the membranous layers was observed, and their thickness was measured Results In all specimens, the pituitary glands were found to be coated by 2 membranous layers, the inner layer being referred to here as the lamina propria and the outer as the pituitary capsule. In all specimens, the 2 membranes were intact with no histological defects. An interstice or cavity between the 2 layers was found on the surface of the adenohypophysis. However,as these 2 layers got closer and closer to each other, they began to adhere on the surface of the neurohypophysis.The thickness of the pituitary capsule was not constant like that of the lamina propria: the inferolateral part of the capsule was thicker than the other parts. The medial wall of the cavernous sinus (CS) was also a bilayered membrane just like the other CS walls: the 2 layers of the medial CS wall were composed of the lateral part of the pituitary capsule and the fibrous layer. Many fibrous trabeculae arising from this fibrous layer divided the CS into several small venous spaces and connected the internal carotid arteries with the medial wall. Conclusions The lateral part of the capsule (dura mater) and the fibrous layer constituted the medial wall of the CS, which has a superior part that is weaker than the thicker inferior part. Invasive adenomas might be a radiological misunderstanding of the extremely displacement of the CS medial wall by the tumor's pushing. While between the tumor and the pituitary capsule, a .safety surgical interface still exists. Key words: Pituitary gland; Anatomy; Cavernous sinus; Pituitary adenoma

Morphometric Study of the Korean Adult Pituitary Glands and the Diaphragma Sellae

To investigate the morphometric characteristics of the pituitary gland and diaphragma sellae in Korean adults. Using the 33 formaline fixed adult cadavers (23 male, 10 female), the measurements were taken at the diaphragma sellae and pituitary gland. The authors investigated the relationship between dura and structures surrounding pituitary gland, morphometric aspects of pituitary gland and stalk, and morphometric aspect of central opening of diaphragma sellae. The boundary between the lateral surface of pituitary gland and the medial wall of cavernous sinus was formed by the thin dural layer and pituitary capsule. The pituitary capsule adherent tightly to the pituitary gland was observed to continue from the diaphragma sellae. Mean width, length, and height of the pituitary gland were 14.3 +/- 2.1, 7.9 +/- 1.3, and 6.0 +/- 0.9 mm in anterior lobes, and 8.7 +/- 1.7, 2.9 +/- 1.1, and 5.8 +/- 1.0 mm in posterior lobes, respectively. Although all dimensions of anterior lobe in female were slightly larger than those in male, statistical significance was noted in only longitudinal dimension. The ratio of posterior lobe to the whole length of pituitary gland was about 27%. The mean thickness of pituitary stalk was 2 mm. The diaphragmal opening was 5 mm or more in 26 (78.8%) of 33 specimen. The opening was round in 60.6% of the specimen, and elliptical oriented in an anterior-posterior or transverse direction in 39.4%. These results provide the safe anatomical knowledge during the transsphenoidal surgery and may be helpful to access the possibility of the development of empty sella syndrome.

Endoscopic endonasal transsphenoidal approach for pituitary adenomas invading the cavernous sinus

In this report, the authors describe their experience with surgical access to the cavernous sinus via a fully transnasal endoscopic approach in 20 cases. Clinical and endocrinological follow-up are discussed. The authors used an endoscopic transsphenoidal approach in 192 patients with pituitary adenomas between September 1997 and January 2008, adding a cavernous sinus approach in 20 patients with invasive tumors during the last 5 years of this period [corrected]. Parasellar extension of the tumor was measured according to the Knosp Scale. Radical tumor removal was achieved in 13 (65%) of 20 patients, and subtotal removal in 7 (35%). The authors used recently defined cavernous sinus approaches in the first 14 cases, including the paraseptal approach in 6, middle turbinectomy in 7, and contralateral middle turbinectomy in 1 case. Combined approaches rather than defined standard cavernous sinus approaches were used in 4 cases and an extended approach in 2. The tumors included nonsecretory adenomas in 5 cases (25%), growth hormone-secreting adenomas in 7 (35%), prolactin-secreting adenomas in 4 (20%), and adrenocorticotropic hormone-secreting adenomas in 4 cases (20%). Normal growth hormone and insulin-like growth factor 1 levels were achieved in 4 patients (57%) with growth hormone adenomas, and remission criteria were obtained in 3 patients with prolactinomas and 3 patients with adrenocorticotropic hormone-secreting adenomas. Compared with transcranial and microscopic transsphenoidal surgery, endoscopic transsphenoidal surgery offers a wide exposure for cavernous sinus medial wall adenomas that enables removal of the adenoma from the medial cavernous sinus wall. Because of the necessity for multidisciplinary treatment to achieve satisfactory results, Gamma Knife surgery and medical therapy should be supplementary treatment options after endoscopic transsphenoidal surgery.

The value of high-field MRI (3 T) in the assessment of sellar lesions

The aim of this study was the evaluation of the normal sellar anatomy in vitro and in vivo with high-field MRI and its application in the diagnosis of sellar pathologies in comparison to standard MRI. All high-field MR images were obtained using a 3 T Bruker Medspec 30/80 Scanner with a head birdcage transmit/receive coil and an actively shielded gradient system with a maximum gradient strength of 45 mT/m. Firstly an in vitro study of the sella turcica was performed to depict normal pituitary and sellar anatomy at high field. After a pilot-study this sequence-protocol was established: A RARE sequence (TR/TE = 7790/19 ms; matrix size, 512 × 512; RARE factor = 8, FOV, 200 mm) was used for T2-weighted coronal, axial and sagittal images. A 3D gradient echo sequence with magnetization-preparation (MP-RAGE, TR/TE/TI = 33.5/7.6/800 ms, matrix size, 512 × 512; FOV, 200 mm, effective slice thickness, 1.88 mm; 3 averages) was used for acquisition of T1-weighted pre- and post-contrast images. Between January 2002 and March 200458 patients were enrolled in this study. Seven patients were examined for suspected microadenoma and in 51 patients 3T MRI was used to obtain additional information about the sellar lesion already known to be present from standard MRI. In 21 cases the accuracy of the imaging findings was assessed afterwards by comparison with intraoperative findings. The infiltration of the medial cavernous sinus wall was suspected on standard MRI on 15 sides (47%), on high-field MRI on 9 sides (28%) and could be verified by intraoperative findings on 6 sides (19%). Accordingly, sensitivity to infiltration was 83% for 3 T and 67% for standard MRI. Specificity was 84% for 3 T and 58% for standard MRI. Moreover, high-field MRI revealed microadenomas in 7 patients with a median diameter of 4 mm (range 2–9 mm). The segments of the cranial nerves were seen as mean 4 hypointense spots (range 2–5 spots) on high-field MRI in contrast to 3 spots (range 0–4 spots) on standard MRI. This difference was considerably significant ( P < 0.001, Wilcoxon rank sum test). The histopathological results revealed pituitary adenoma in 16 patients and non-adenomatous sellar pathologies such as Rathke's cleft cyst, sarcoidosis, meningeoma and metastasis in 5 patients. High-field MRI is superior to standard MRI for the prediction of invasion of adjacent structures in patients with pituitary adenomas and improves surgical planning of sellar lesion.