Lost or fragmented bony septum of the optic canal facing the sphenoid sinus: a histological study using elderly donated cadavers.

PURPOSE: To histologically describe a direct contact (the so-called dehiscence) of the optic nerve (ON) and/or internal carotid artery (ICA) to the mucosa of posterior paranasal sinuses represented by the sphenoid sinus (SS). METHODS: Observations of histological sections of unilateral or bilateral skull bases (parasellar area and orbital apex) from 22 elderly cadavers were made. RESULTS: A bony septum was less than 300 µm between the SS and ICA and 200 µm between the SS and optic nerve. Parts of the septa were sometimes absent due to fragmentation and holes of the bony lamella (2/22 facing the ICA; 4 facing the ICA in combination with an absent bony septum facing the nerve). In these dehiscence sites, the SS submucosal tissue attached to a thick sheath (50-100 µm in thickness) enclosing the optic nerve and ophthalmic artery and/or the ICA adventitia (50-200 µm in thickness). The ICA sometimes contained a sclerotic plaque that attached to or even protruded into the SS. With or without dehiscence, the SS mucosa was always thin (50-100 µm in thickness) and accompanied no mononuclear cellular infiltration or tumor. CONCLUSIONS: A thin bony septum of the optic nerve or ICA had been notable as a danger point during surgery, but even a 0.05-mm-thick bone lamella might be an effective barrier against cellular infiltration or bacterial invasion from the SS. Fragmentation and holes of the bony lamella in 4 cadavers might allow cellular invasion to the optic nerve. Accordingly, unknown immunological cross talks might occur to cause demyelination.

Characteristics of meningitis following transsphenoidal endoscopic surgery: a case series and a systematic literature review.

BACKGROUND: Meningitis occurs in 0.8-1.5% of patients undergoing neurosurgery. The aim of the study was to evaluate the characteristics of meningitis after endoscopic endonasal transsphenoidal surgery (EETS) comparing the findings retrieved to those highlighted by literature search. MATERIALS AND METHODS: Patients treated by EETS during an 18-year period in the Department of Neurosurgery of 'Federico II' University of Naples were evaluated and included in the study if they fulfilled criteria for meningitis. Epidemiological, demographic, laboratory, and microbiological findings were evaluated. A literature research according to PRISMA methodology completed the study. RESULTS: EETS was performed on 1450 patients, 8 of them (0.6%) had meningitis [median age 46 years (range 33-73)]. Endoscopic surgery was performed 1-15 days (median 4 days) before diagnosis. Meningeal signs were always present. CSF examination revealed elevated cells [median 501 cells/µL (range 30-5728)], high protein [median 445 mg/dL (range 230-1210)], and low glucose [median 10 mg/dL (range 1-39)]. CSF culture revealed Gram-negative bacteria in four cases (Klebsiella pneumoniae, Escherichia coli, Alcaligenes spp., and Haemophilus influenzae), Streptococcus pneumoniae in two cases, Aspergillus fumigatus in one case. An abscess occupying the surgical site was observed in two cases. Six cases reported a favorable outcome; two died. Incidence of meningitis approached to 2%, as assessed by the literature search. CONCLUSIONS: Incidence of meningitis after EETS is low despite endoscope goes through non-sterile structures; microorganisms retrieved are those present within sinus microenvironment. Meningitis must be suspected in patients with persistent fever and impaired conscience status after EETS.

"Intrasellar Balloon Technique" in intraoperative MRI guided transsphenoidal endoscopic surgery for sellar region tumors. Usefulness on image interpretation and extent of resection evaluation. Technical note.

BACKGROUND: Intraoperative magnetic resonance imaging (iMRI) is an effective and proven tool in transsphenoidal endoscopic surgery. However, image interpretation is not always easy and can be hindered by the presence of blood, tumor remains or the displacement of surrounding structures. In this article we present a novel technique based on using intrasellar ballons to reduce these difficulties and facilitate the surgeon's intraoperative assessment by iMRI. METHODS: Eighteen patients with pituitary macroadenomas underwent transsphenoidal surgery during 2013-2014 under low-field iMRI control (PoleStar N20, 0.15 T). Intrasellar balloons were used in all of them to assess the presence of tumoral remnants. We compared the findings in iMRI and postoperative high-field MRI control scans and also analyzed the number of intermediate imaging controls needed during surgery using this technique. RESULTS: In total, of the 18 patients, 14 underwent a complete resection. In the remaining four patients, a safe maximal resection was performed, leaving a remnant because of cavernous sinus invasion. In all cases, the balloons were a major help in distinguishing the anatomical structures from the tumoral remnants. Fewer imaging controls were required, and there were no false-positives or negative intraoperative findings. No complications related to the technique were registered. CONCLUSION: The "intrasellar balloon technique" is a useful tool that facilitates surgeons' intraoperative decision making. It is an important contribution to overcome the limitations of low-field iMRI as it provides a precise delineation of the resection margins, reduces false-positives and -negatives, and decreases the number of intermediate imaging controls required.

Metastatic Colon Cancer in the Pituitary: A Case Report with Review of Literature.

We report a rare case of metastatic colonic adenocarcinoma to the pituitary gland in a 58-year-old who presented with visual decline and panhypopituitarism. He underwent urgent transsphenoidal endoscopic surgery with significant improvement of his vision, followed by adjuvant fractionated radiotherapy to the resection cavity. He made a satisfactory recovery, but regrettably died from COVID-19 9 weeks after completion of radiotherapy. A multidisciplinary approach is essential for optimal management of this condition due to its rarity and complexity.

Simulating Internal Carotid Artery Injury during Transsphenoidal Transclival Endoscopic Surgery in a Perfused Cadaver Model.

Introduction Managing internal carotid artery (ICA) injury during extended endoscopic transsphenoidal surgery is an extreme challenge. We aimed to find a possible surgical treatment strategy. Methods We operated seven fresh, perfused cadaver heads with a transsphenoidal endoscopic approach of the ICA using a three-dimensional-high definition (3D-HD) endoscope. We made a paraclival ICA leak, which we tried to manage with clips and microsutures. Results Accurate transsphenoidal clip application on the ICA was impossible with standard aneurysm clips and applier. It was only feasible with a 9 mm slightly bended clip that could be opened from the inside and be applied with a dedicated flexible thin applier. Transsphenoidal suturing of an ICA leak was impossible from the ipsilateral nostril or with standard microinstruments. Suturing was only feasible from the contralateral nostril using flexible microinstruments with a thin 90-mm shaft. This was technically very challenging and involved a steep learning curve. Conclusion Tamponade with muscle or fat and a quick transfer to the angiography suite for endovascular control remains the preferable option in case of an ICA leak during endoscopic transsphenoidal surgery. If tamponade gives insufficient initial control, ICA clipping could be possible with dedicated instruments, with risk of increasing the defect, stenosis, or occlusion of the vessel. Transsphenoidal ICA suturing remains extremely difficult, and laboratory practice seems essential.

Risks and Benefits of Endoscopic Transsphenoidal Surgery for Nonfunctioning Pituitary Adenomas in Patients of the Ninth Decade.

BACKGROUND: The population older than 80 years of age (very elderly) is increasing, and the management of these patients with pituitary surgery is controversial. OBJECTIVE: To determine the prevalence of pituitary tumors in elderly patients and to determine the safety of endoscopic transsphenoidal pituitary surgery for nonfunctioning pituitary adenomas in patients aged older than 80 years. METHODS: This retrospective study included elderly (65-75 years old) and very elderly consecutive patients operated between 2007 and 2015 for nonfunctioning pituitary adenomas. Tumor characteristics, comorbidities, pre- and postoperative visual and endocrinologic status, and postoperative complications were compared. RESULTS: Of the total 623 operated patients, 307 had nonfunctioning pituitary adenomas. Twenty-three percent (n = 143) of all patients were aged older than 65 years, whereas 2.56% (n = 16) were aged older than 80 years. Gonadotroph and nonimmunoreactive tumors occurred in 81% of patients aged older than 65 years. The study groups were Group A, comprising 15 patients aged older than 80 years, and Group B, comprising 49 patients aged 65-75 years. No presurgical statistical differences were noted between the 2 groups. Complete tumor resection was achieved in 53.3% of Group A and 73.5% of Group B. Postsurgical visual status improved significantly in Group A than in Group B (P = 0.0012). No deaths occurred, and no group differences were noted in the postoperative complications. CONCLUSIONS: Age exceeding 80 years is not by itself a predictor of worse clinical outcome of endoscopic transsphenoidal pituitary surgery for nonfunctioning adenomas. Emphasis should be placed on visual pathway decompression for the quality of life in very old people.

Transclival pseudomeningocele secondary to ecchordosis physaliphora: case report and literature review.

We describe a 52-year-old woman who presented with meningitis secondary to a pseudomeningocele within the sphenoid sinus derived from a bony defect in the clivus. The bony defect was radiologically characteristic of an ecchordosis physaliphora (EP). She underwent surgical repair of the defect and had resolution of her symptoms. This case report will discuss the second case of transclival pseudomeningocele in the English literature and present EP as a cause.