Refining Endoscopic and Combined Surgical Strategies for Giant Pituitary Adenomas: A Tertiary-Center Evaluation of 49 Cases over the Past Year

Abstract

Background/Objectives: Giant pituitary adenomas (GPAs) pose significant surgical challenges due to their large size, parasellar/suprasellar extensions, and proximity to critical neurovascular structures. Although the endoscopic endonasal approach (EEA) is preferred for pituitary tumors, achieving gross total resection (GTR) in GPAs remains difficult. Additional transcranial approaches may improve resection rates while minimizing morbidity. This study evaluates the impact of endoscopic and combined surgical approaches on resection outcomes using a classification system previously defined in GPA patients treated over the past year. Methods: Among 517 pituitary adenomas treated in our clinic between September 2023 and September 2024, 49 GPA patients underwent endoscopic endonasal, transcranial, or combined surgery. Their medical records and surgical videos were retrospectively reviewed. Data included demographics, symptoms, imaging, surgical details, and follow-up outcomes. Tumor resection rates were analyzed based on the "landmark-based classification", considering radiological and pathological features and surgical approach. Results: The mean age was 45.5 years (female/male: 14/35). Zone distribution was 8 (Zone 1), 21 (Zone 2), and 20 (Zone 3). GTR was achieved in 34.6%, near-total resection in 36.7%, and subtotal resection in 28.5%. Endoscopic surgery was performed in 41 patients, combined surgery in 7, and a transcranial approach in 1. Complications included diabetes insipidus (9/49), cerebrospinal fluid leakage (2/49), apoplexy (2/49), hypocortisolism (3/49), epidural hematoma (1/49), and epistaxis (1/49). Conclusions: While EEA is effective for Zone 1 and 2 GPAs, Zone 3 tumors often require combined or transcranial approaches for better resection. A multimodal strategy optimizes tumor removal while minimizing morbidity. Individualized surgical planning based on tumor classification is crucial for improving outcomes.

Keywords: combined surgery; endoscopic endonasal approach; giant pituitary adenomas; pituitary; skull base.

Figure 1

(A). Landmark-based classification sagittal plane view (B). Landmark-based classification coronal plane view (C). Zone 1 tumor: preoperative and postoperative NTR imaging (D). Zone 2 tumor: preoperative and postoperative GTR imaging.

Figure 2

(A1). Preoperative MRI of a Zone 3 multilobular-shaped tumor and postoperative MRI following near-total resection using a combined approach. (A2). Illustrative representation of the anatomical extension way of a giant adenoma. (A3). Demonstration of the close relationship between optic nerve and tumor capsule during the transpterional approach. (B). Preoperative MRI of GA extending into the frontal lobe and lateral ventricle and postoperative MRI following NTR using a combined approach (EEA + Transpterional). (C). Preoperative MRI of GA extending into lateral ventricle and postoperative MRI following NTR using a combined approach (EEA + Transcallosal). (CN2: Cranial Nerve 2, tc: tumor capsule).

Figure 3

(A). Intraoperative view of a Zone 3 tumor with NTR and its extension posterior to the carotid artery and into the temporal region. (B). Demonstration of the EEA boundary in the temporal region using intraoperative navigation, along with preoperative MRI and postoperative MRI after GTR. (C). NTR of a retroclival-extending GA using intraoperative navigation, with preoperative and postoperative MRI images. oc: optic chiasm, t: tumor, C: carotid artery. Green Label is the border of endoscopic surgery.