Endoscopic endonasal surgical management of giant pituitary adenomas with extension into ventricle system

Abstract

Objective: to estimate the results of endoscopic endonasal surgical management of giant pituitary adenomas (GPAs) with extension into ventricular system (VS), to study the peculiarities of surgical techniques.

Materials and methods. 49 adult patients with GPAs with extension into VS were included in the study. The depth of research 2016-2021. This is a consecutive sampling of 1339 pituitary adenomas. GPAs with extension into VS made up 3.66% (49/1339) among all treated pituitary adenomas, and 43.4% among 113 GPAs. Distribution by gender – 18 (36.7%) women and 31 (63.3%) men. Average age was 54.1±11.3 years.

Results. The largest consecutive series of GPAs with extension into VS that underwent endoscopic endonasal surgery was analyzed. Gross total resection was achieved in 32.7% (16/49), subtotal – 42.9% (21/49), partial – 12.2% (6/49), contraindications for tumor removal were issued in 12.2% (6/49) cases, these patients underwent extended biopsy and ventriculoperitoneal shunting in 4 patients. In 67.4% (33/49) was admitted visual function improvement. In 12.2% (6/49) vision remained at preoperative level, with no visual impairment. In 20.4% (10/49) of cases, vision deteriorated immediately after surgery. Upon re-examination at 6‒8 weeks in this group, vision returned to baseline in 60% (6/10) of patients. An immunohistochemical study found that 89.8% of the tumors were hormonally inactive. There was allocated a separate group of null cell pituitary adenomas, which accounted for 18.9% of cases. ACTH, LH-FSH, GH, TTH, prolactin secreting PAs were detected in 30.6%, 24.5%, 16.3%, 8.2% and 2.0% respectively. Hypopituitarism was diagnosed in 30.6% (15/49) of patients. Diabetes insipidus was detected for the first time in the postoperative period in 12.2% (6/49) of patients. 14.3% (7/49) of the cases of postoperative cerebrospinal fluid leak were diagnosed. Meningitis developed in 8.1% (4/49). The mortality rate was 6.1% (3/49).

Conclusions. An analysis of complications in the early postoperative period found that the incidence of complications in GPAs with extension into VS was statistically significantly higher when compared to the cohort of patients who underwent endoscopic endonasal surgery for pituitary adenomas removal, indicating the complexity of this pathology. Despite the significant increase in the complexity of endoscopic interventions and still considerable threats of postoperative cerebrospinal fluid leak in the opening of the VS, we can already consider endonasal operations in the vast majority of GPAs as the method of choice. A new classification approach to the study group of GPAs was proposed. It allows us to separate the relatively low-risk and high-risk groups of high-flow intraoperative cerebrospinal fluid leak, which is directly correlated with the risks of postoperative complications and mortality in our study. In addition, we emphasize a special, although the smallest group of GPAs with extension into the third ventricle (type 3). Such cases require special attention and the decision to have ventriculoperitoneal shunting before or immediately after the removal of the tumor.