en Brain Tumors Clinical Trial <p><strong>Background and Aim:</strong> Pituitary adenomas commonly require endoscopic transsphenoidal surgery (ETSS). Although ETSS is minimally invasive, intraoperative cerebrospinal fluid (CSF) leaks occur in up to 50% of cases and can lead to meningitis or pneumocephalus if not well repaired. Autologous fat grafting from the periumbilical region is effective for dural reconstruction but carries donor-site morbidity and surgical-site infection (SSI). Buccal fat harvested intraorally reduces abdominal morbidity but risks contamination from oral flora. We evaluated a novel endonasal nasal-aperture approach to buccal fat harvest, hypothesizing comparable efficacy with fewer donor-site complications.<br> <strong>Methods and Materials/Patients:</strong> In a single-center, single-blinded, nonrandomized trial at Alzahra Hospital (affiliated with Isfahan University of Medical Sciences, Isfahan City, Iran, 2024&ndash;2025), 30 patients with macroadenomas undergoing ETSS were allocated 1:1 to nasal-aperture buccal fat harvest (n=15) or standard periumbilical abdominal fat harvest (n=15). The same surgeon used consistent anesthesia and postoperative protocols. The primary outcome was postoperative CSF leak. Secondary outcomes included operative time, length of stay, postoperative bleeding, SSI, donor-site pain, facial numbness, and cosmetic sequelae. Follow-up visits occurred at 2 weeks, 1, 2, 4 months, and 1 year. Statistical comparisons used the t-test, Mann-Whitney U test, and chi-square test (&alpha;=0.05).</p> <p><strong>Results:</strong> Groups were demographically similar (mean age 48.2&plusmn;3 years; 56.7% male; mean BMI 25.4&plusmn;1.2 kg/m&sup2;). Operative time (116.7&plusmn;3.2 vs 115.9&plusmn;3.8 min, P=0.54) and hospital stay (4.6&plusmn;0.5 vs 4.5&plusmn;0.5 days, P=0.67) did not differ between study groups. Both groups achieved 100% CSFleak closure without graft failure. The nasal-aperture group had significantly lower postoperative bleeding (20% vs 66.7%, P=0.01) and SSI (6.7% vs 33.3%, P=0.04). Transient facial numbness occurred in 6.7% of the nasal-aperture group; one immediate asymmetry resolved within 24 hours. No persistent donor-site complications or neurologic deficits were observed.</p> <p><strong>Conclusion</strong>: Endonasal nasal-aperture buccal fat harvest during ETSS provides equivalent CSFleak prevention to abdominal fat grafting while reducing bleeding, infection risk, and donor-site morbidity, and improving cosmetic outcomes. Larger randomized, multicenter trials with longer follow-up and patient-reported outcomes are warranted.</p> Buccal fat, Endoscopic transsphenoidal pituitary surgery (ETSS), Cerebrospinal fluid (CSF) leak 0 0 http://irjns.org/browse.php?a_code=A-10-1313-1&slc_lang=en&sid=1 Ahmad Rezaeian 100319475328460012716 100319475328460012716 No Department of Otorhinolaryngology, School of Medicine, Al‐Zahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. Mohammadreza Moznebiisfahani 100319475328460012717 100319475328460012717 No Department of Neurosurgery, School of Medicine, Al‐Zahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. Zahra Akbari 100319475328460012718 100319475328460012718 Yes Department of Otorhinolaryngology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.