Giant Pituitary Tumors Can Still Be Successfully Removed via Endoscopic Endonasal Approach

Understanding Giant Pituitary Adenomas: Clinical Overview and Surgical Innovation

Giant pituitary adenomas—tumors exceeding 4 cm in diameter—present significant challenges in neurosurgery due to their size and proximity to critical brain structures. In a recent study involving 17 patients (8 male, 9 female) aged between 35 and 67 years, researchers explored the effectiveness of endoscopic endonasal surgery for complete tumor resection. All patients exhibited classic symptoms such as chronic headaches and progressive vision loss, directly linked to optic nerve compression caused by the expanding mass. Tumor diameters ranged from 4.2 to 6.2 cm, classifying them as giant adenomas with suprasellar or even intraventricular extension into the third ventricle.

Surgical Technique: Precision and Minimally Invasive Access

The procedure began with general anesthesia and careful patient positioning—supine with slight head extension to optimize surgical access. Prior to incision, all patients underwent preoperative lumbar drainage catheter placement to reduce intracranial pressure during surgery. Standard antiseptic preparation of the nasal cavity and face was performed, followed by transnasal navigation using high-definition endoscopy.

Surgery proceeded through the natural corridor between the middle turbinate and nasal septum. To enhance visibility and control bleeding, cottonoids soaked in 0.01% epinephrine solution were used to constrict blood vessels and expand the operative pathway. Once the sphenoid sinus opening was identified, a pedicled nasal septal mucosal flap was harvested and set aside for later reconstruction—a crucial step in preventing postoperative cerebrospinal fluid (CSF) leaks.

The anterior-inferior wall of the sphenoid sinus was carefully opened using a high-speed drill, and the intersinus septa were removed. Key anatomical landmarks—including bilateral carotid artery prominences within the sphenoid—were clearly visualized to ensure safe orientation. The entire sellar floor was then exposed, and an appropriately sized craniectomy was created based on tumor dimensions. In select cases with extensive upward growth, partial removal of the tuberculum sellae was necessary to achieve full exposure.

Endoscopic Resection: Step-by-Step Tumor Removal

After dural incision, a small specimen was sent for intraoperative pathology confirmation. Using angled and straight suction devices under continuous endoscopic visualization, surgeons meticulously debulked the tumor in a piecemeal fashion. As the tumor cavity expanded, the endoscope was advanced into the sella, above the diaphragma sellae, and even into the third ventricle when needed, allowing direct visualization of residual tissue.

Critical care was taken to avoid aggressive curettage, which could damage any remaining normal pituitary gland tissue. Instead, gentle suction techniques preserved healthy endocrine structures while maximizing tumor removal. In many instances, the resection resulted in direct communication between the resection cavity and the third and lateral ventricles—an expected outcome given the tumor's original extension—but required special attention to prevent postoperative complications.

Postoperative Outcomes: High Success Rates and Rapid Recovery

Of the 17 patients, 12 achieved gross total resection, while 5 had near-total resections due to adherence near vital neurovascular structures. All patients reported marked improvement in clinical symptoms post-surgery, particularly in visual acuity and headache severity. Transient polyuria—a common sign of temporary posterior pituitary dysfunction—was observed in every case but resolved completely with short-term desmopressin (synthetic vasopressin) therapy. By discharge, all patients had normalized urinary output without hormonal instability.

No instances of CSF rhinorrhea or intracranial infection occurred, thanks to meticulous closure techniques and continued lumbar drainage for several days after surgery. Two patients showed minor postoperative hemorrhage within the tumor bed, but these resolved spontaneously without neurological consequences and were fully absorbed by follow-up imaging.

Importantly, there were no perioperative deaths, highlighting the safety and efficacy of this approach even for large, complex tumors.

Advantages and Considerations of Endoscopic Endonasal Surgery

The endoscopic endonasal transsphenoidal approach has emerged as the gold standard for treating pituitary adenomas, offering superior visualization, minimal tissue disruption, faster recovery times, and higher rates of complete resection compared to traditional microscopic methods. Its ability to navigate around and above the sella makes it especially effective for giant tumors extending into the third ventricle.

Why This Approach Works for Large Tumors

Several key factors contribute to successful outcomes in these challenging cases:

Low invasiveness despite tumor size: Many giant adenomas remain non-aggressive, preserving the integrity of surrounding structures like the cavernous sinus walls, making en bloc or near-complete removal feasible.
Soft tumor consistency: These tumors are often friable and easily aspirated, allowing efficient debulking using suction instruments rather than sharp dissection.
Minimal adhesion to third ventricular walls: Even with intraventricular extension, most tumors do not deeply infiltrate the ependymal lining, reducing the risk of injury during resection.
Use of lumbar drainage: Preoperative CSF diversion helps lower intracranial pressure, prevents premature diaphragmatic collapse, and creates more working space—especially beneficial when removing superiorly projecting components.
Robust skull base reconstruction: Given the high risk of CSF leak after wide dural openings, multilayer closure is essential. The use of autologous fat grafts, synthetic dura substitutes, fascial patches, and the pedicled nasal septal flap provides a watertight seal that promotes healing and prevents leakage.

Conclusion: A Safe and Effective Option for Complex Cases

This study demonstrates that even giant pituitary tumors—with extensions into the third ventricle—can be safely and effectively managed using modern endoscopic endonasal techniques. With proper patient selection, advanced imaging, experienced surgical teams, and meticulous reconstructive strategies, neurosurgeons can achieve excellent outcomes with minimal morbidity. As technology and technique continue to evolve, the endoscopic approach will likely become the preferred method for managing even the most complex sellar and parasellar lesions.