Identification of the Extradural and Intradural Extension of Pituitary Adenomas to the Suprasellar Region: Classification, Surgical Strategies, and Outcomes

Predictive value of suprasellar extension for intracranial infection after endoscopic transsphenoidal pituitary adenoma resection

OBJECTIVE

To investigate the relationship between suprasellar extension (SSE) and intracranial infection after endoscopic endonasal transsphenoidal approach (EETA) for pituitary adenoma resection.

METHODS

We retrospectively analyzed 94 patients with suprasellar extended pituitary adenoma admitted to the Department of Neurosurgery of the Affiliated Hospital of Guilin Medical College from January 2018 to December 2021. We measured the preoperative magnetic resonance sagittal SSE and collected clinical data and divided the patients into groups according to the presence of postoperative intracranial infection. The critical value for the SSE was calculated by using a working characteristic curve for the subjects. The risk factors for intracranial infection after EETA resection of pituitary adenomas were analyzed by multivariate regression analysis.

RESULTS

Among the 94 patients, 12 cases (12.8%) were placed in the infection group and 82 cases (87.2%) in the non-infection group. The cut-off value for the SSE in the sagittal position was 15.6 mm, the sensitivity was 75%, the specificity was 87.8%, and the area under the curve (AUC) was 0.801. The coronary cut-off value for the SSE was 15.8 mm, the sensitivity was 66.7%, the specificity was 79.3%, and the AUC was 0.787. The SSE values in the sagittal and coronal positions were correlated with postoperative intracranial infection (P < 0.05). After univariate analysis, those with significant differences were included in the multivariate regression analysis. It was concluded that the extension distance of the tumor above the sella in the sagittal position was ≥ 15.6 mm, the tumor texture was hard, and the postoperative cerebrospinal fluid leakage were the independent risk factors for intracranial infection after EETA resection of suprasellar extended pituitary tumors (P < 0.05).

CONCLUSIONS

The value of SSE on sagittal MRI can predict intracranial infection in patients with suprasellar extended pituitary adenoma after endoscopic endonasal transsphenoidal resection. This finding recommends neurosurgeons pay more attention to the imaging characteristics of pituitary adenomas and select appropriate treatment plans in combination with the intraoperative conditions to reduce the incidence of intracranial infection.

Pituitary adenoma with oculomotor cistern extension: membranous anatomy and clinical application

BACKGROUND

The anatomical basis of pituitary adenomas (PAs) with oculomotor cistern (OC) extension as a growth corridor is overlooked in the literature. In this paper, the authors use the technique of epoxy sheet plastination to study the membranous structure of the OC and validate the results by retrospective analysis of patients with OC extension.

METHODS

Eighteen specimens were used to study the membranous anatomy surrounding the OC using the epoxy sheet plastination technique. Thirty-four patients with OC extension were retrospectively reviewed.

RESULTS

The OC consisted of two thin membranous layers. The inner layer was extended by the arachnoid layer from the posterior fossa, and the lateral layer consisted of the dura mater sinking from the roof of the cavernous sinus. The oculomotor nerve is more likely to displace with a superolateral trajectory due to the weakness of the posterior dura and the relatively large space in the medial and posterior trajectories, which is consistent with the intraoperative observations. Among the anatomical factors that affect the PA by OC extension, we found that the relative position of the internal carotid artery (ICA) and posterior clinoid process may lead to the narrowing of the OC. Of 34 cases, 28 patients achieved total resection. Among 24 preoperative patients with oculomotor nerve palsy, 16 cases were relieved to varying degrees postoperatively. There was no ICA injury or severe intracranial infection found in any of the patients.

CONCLUSIONS

Extension into the OC is influenced by two anatomical factors: a weak point in the dura in the posterior OC and a potential space beyond this region of the dura. Meticulous knowledge of the membranous anatomy in endoscopic endonasal surgery is required to safely and effectively resect PA with OC extension.

Side-Firing Intraoperative Ultrasonograhy for Resection of Giant Pituitary Adenomas

BACKGROUND

Suprasellar extension, cavernous sinus invasion, and involvement of intracranial vascular structures and cranial nerves are among the challenges faced by surgeons operating on giant pituitary macroadenomas. Intraoperative tissue shifts may render neuronavigation techniques inaccurate. Intraoperative magnetic resonance imaging can solve this problem, but it may be costly and time consuming. However, intraoperative ultrasonography (IOUS) allows for quick, real-time feedback and may be particularly useful when facing giant invasive adenomas. Here, we present the first study examining technique for IOUS-guided resection specifically focusing on giant pituitary adenomas.

OBJECTIVE

To describe the use of a side-firing ultrasound probe in the resection of giant pituitary macroadenomas.

METHODS

We describe an operative technique using a side-firing ultrasound probe (Fujifilm/Hitachi) to identify the diaphragma sellae, confirm optic chiasm decompression, identify vascular structures related to tumor invasion, and maximize extent of resection in giant pituitary macroadenomas.

RESULTS

Side-firing IOUS allows for identification of the diaphragma sellae to help prevent intraoperative cerebrospinal fluid leak and maximize extent of resection. Side-firing IOUS also aids in confirmation of decompression of the optic chiasm via identification of a patent chiasmatic cistern. Furthermore, direct identification of the cavernous and supraclinoid internal carotid arteries and arterial branches is achieved when resecting tumors with significant parasellar and suprasellar extension.

CONCLUSIONS

We describe an operative technique in which side-firing IOUS may assist in maximizing extent of resection and protecting vital structures during surgery for giant pituitary adenomas. Use of this technology may be particularly valuable in settings in which intraoperative magnetic resonance imaging is not available.

A Factorial Analysis on Visual Outcomes of Transsphenoidal Surgery for Pituitary Macroadenoma

Objective  Sellar lesions are possible reversible causes of vision loss. This study is to provide quantitative objective measurement of efficacy of surgery for non-functioning pituitary adenoma and discuss different factors that could affect visual outcome of non-functioning pituitary adenoma.

Method  This is a single centre, retrospective study conducted at a tertiary neurosurgery referral centre. 108 cases of sellar tumors which underwent surgery during the 3-year period from early June 2015 to late May 2018 were reviewed. Pituitary adenoma that were non-functioning and without apoplexy at initial presentation were selected for the study. We have analyzed the correlation of different factors with the visual outcome, including the extent of vertical decompression in terms of change in tumor height post operation and the extent of lateral decompression in terms of change in Knosp grading. Visual outcome was represented by the visual impairment score (VIS), an integrated measurement of visual acuity and visual field deficit.

Results  Preoperative absolute tumor height and supracarotid height correlated with preoperative VIS scale ( p  ≤ 0.01). Absolute Knosp grading correlates significantly with VA ( p  = 0.001) and VF ( p  ≤ 0.001) of that particular eye. Although most patients had an objective improvement in visual acuity (VA) (88%) and visual field (VF) (99%) after operation, a larger reduction in tumor height and successful Knosp downgrading after surgery is associated with better VIS improvement. ( p  = 0.025) Change in supracarotid height shows trend in correlating with change in VIS ( p  = 0.084).

Conclusion  Height of tumor measured from genu of cavernous ICA correlates better with visual outcome than absolute tumor height. The extent of both vertical and lateral decompression of non-functioning pituitary adenoma are important determinants that lead to better visual outcome. As endoscopic approach is able to achieve a greater degree of lateral decompression, it is a preferred approach in pituitary surgery to achieve a better visual outcome.

Radiological Knosp, Revised-Knosp, and Hardy–Wilson Classifications for the Prediction of Surgical Outcomes in the Endoscopic Endonasal Surgery of Pituitary Adenomas: Study of 228 Cases

Purpose

To evaluate which radiological classification, Knosp, revised-Knosp, or Hardy–Wilson classification, is better for the prediction of surgical outcomes in the endoscopic endonasal transsphenoidal (EET) surgery of pituitary adenomas (PAs).

Methods

This is a retrospective study of patients with PAs who underwent EET PA resection for the first time between January 2009 and December 2020. Radiological cavernous sinus invasiveness was defined as a Knosp or revised-Knosp grade >2 or a grade E in the Hardy–Wilson classification.

Results

A total of 228 patients with PAs were included. Cavernous sinus invasion was evident in 35.1% and suprasellar extension was evident in 74.6%. Overall, surgical cure was achieved in 64.3% of patients. Surgical cure was lower in invasive PAs than in non-invasive PAs (28.8% vs. 83.1%, p < 0.0001), and the risk of major complications was higher (13.8% vs. 3.4%, p = 0.003). The rate of surgical cure decreased as the grade of Knosp increased (p < 0.001), whereas the risk of complications increased (p < 0.001). Patients with Knosp 3B PAs tended to achieve surgical cure less commonly than Knosp 3A PAs (30.0% vs. 56.0%, p = 0.164). Similar results were observed based on the invasion and extension of Hardy–Wilson classification (stage A–C 83.1% vs. E 28.8% p < 0.0001, grade 0–II 81.1% vs. III–IV 59.7% p = 0.008). The Knosp classification offered the greatest diagnostic accuracy for the prediction of surgical cure (AUC 0.820), whereas the invasion Hardy–Wilson classification lacked utility for this purpose (AUC 0.654).

Conclusion

The Knosp classifications offer a good orientation for the estimation of surgical cure and the risk of complications in patients with PAs submitted to EET surgery. However, the invasion Hardy–Wilson scale lacks utility for this purpose.