Gauze swabbing technique for safe dissection of pituitary tumors

In endoscopic transsphenoidal surgery (ETSS) for pituitary neuroendocrine tumor (Pit-NET), also known as a pituitary adenoma, identification and dissection of the boundary between the tumor and the normal anterior pituitary gland are important surgical techniques. In this study, we introduce the Gauze Swabbing Technique (GST), in which boundary dissection is performed using shear stress, and examine its surgical outcomes.

A total of 271 patients with nonfunctioning pituitary adenoma/Pit-NET who underwent ETSS at our institution between April 2014 and September 2025 were included. The patients were divided into an early group of 135 cases before the introduction of GST and a later group of 136 cases in which GST was used, and surgical outcomes were compared. Propensity score matching was performed using age, sex, tumor size, Knosp grade, tumor consistency, cavernous sinus invasion, preoperative diabetes insipidus, preoperative ocular motility disorder, and preoperative anterior pituitary dysfunction as covariates, and surgical outcomes were compared in the matched cohort by conditional logistic regression.

Propensity score matching yielded 100 patients in each group, and all standardized differences in background factors were less than 0.1, indicating good balance between the groups. In the post-matching comparison, there were no significant differences between the early group and the GST group in gross total resection rate, new pituitary dysfunction, new diabetes insipidus, worsening of ocular motility disorder, or intraoperative cerebrospinal fluid leakage.

GST is a technique in which boundary dissection is performed by applying gentle shear stress through rotational movement of gauze along the interface between the tumor and the normal anterior pituitary gland, and it may enable tumor removal while preserving the membranous structure. Based on the results of the propensity score matching analysis, GST shows safety and efficacy comparable to those of conventional techniques and may be a useful option for boundary dissection in ETSS for pituitary adenoma/Pit-NET.