Introduction: Giant pituitary adenomas (GPAs), defined as having maximal diameter >4cm, are complex neurosurgical cases due to high rates of extension into multicompartmental anatomical spaces. We retrospectively assessed safety and complication rates in endoscopic versus microscopic transsphenoidal approaches.
Methods: A retrospective chart review of the Keck Medical Center of USC Pituitary Database from 1995-2018 identified 44 patients who underwent transsphenoidal surgery for GPAs. Preoperative characteristics, surgical, and clinical outcomes were analyzed.
Results: The mean patient age was 55.9 years and 33 patients (75.0) were male. The mean maximal tumor diameter was 47.3 mm (range 40-80 mm). Twenty-two GPAs were resected microscopically and 22 endoscopically. Surgical complications included postoperative cerebrospinal fluid leak (11.4%), hematoma (9.1%), hydrocephalus (9.1%), epistaxis (6.8%), meningitis (6.8%), stroke (6.8%), cranial nerve paresis (2.3%) and vision loss (2.3%). Endocrine complications included transient (11.4%) and permanent (2.3%) diabetes insipidus, symptomatic hyponatremia (11.4%) and new hypopituitarism (6.8%). There were no significant differences between endoscopic and microscopic approaches with regard to surgical complications (31.8% versus 45.5%; p=0.353) or endocrine complications (31.8% versus 18.2%; p=0.296). There was one postoperative mortality (2.3%) following microscopic surgery. Median hospital length of stay and rates of early readmission, early reoperation, and tumor progression did not significantly differ between endoscopic and microscopic cases. Gross total resection was achieved in 11.4% of patients (13.6% endoscopic versus 9.1% microscopic; p=1.000) and was significantly reduced in tumors with cavernous sinus invasion (3.3% versus 28.6%; p=0.029). Extent of resection was not associated with resolution of headache, visual loss or hormonal symptoms. Follow-up imaging showed tumor progression in 8 patients (22.2%) over a mean of 50.4 months.
Conclusions: Endoscopic and microscopic transsphenoidal surgeries are both effective approaches for resecting complex GPAs. However, given the anatomic complexity of most cases and increased complication rates, surgeons must carefully consider staged or multimodality care including craniotomy and adjuvant radiosurgery.
Patient Care: Although the morbidities associated with surgical resection of giant PAs are widely reported in the literature, there is still no definite consensus on which of several operative approaches offers better outcomes. This series assesses factors associated with poor clinical outcomes in consecutive patients with giant PAs treated at a single institution. By identifying specific preoperative predictors of outcomes in a direct comparison of surgical techniques, our analysis aims to help direct the implementation of new technology in the modern management of giant PAs.
Learning Objectives: 1. Discuss the operative challenges and associated complications of transsphenoidal resection of giant pituitary adenomas.
2. Identify factors associated with extent of tumor resection, including specific extension patterns.
3. Describe the importance of adjunctive therapy for subtotally resected tumors.
References: 1. Juraschka K, Khan OH, Godoy BL, et al. Endoscopic endonasal transsphenoidal approach to large and giant pituitary adenomas: institutional experience and predictors of extent of resection. J Neurosurg. 2014;121:75–83.
2. Nishioka H, Hara T, Nagata Y, et al. Inherent Tumor Characteristics That Limit Effective and Safe Resection of Giant Nonfunctioning Pituitary Adenomas. World Neurosurg. 2017;106:645–652.