Classification of cavernous segment of internal carotid artery in patients with Knosp grade 4 pituitary tumor
YANG Jianing
GUI Songbai
BAI Jiwei
CAO Lei
LIU Chunhui
ZHU Haibo
ZHANG Yazhuo
ZONG Miao
LI Chuzhong
Abstract：Objective To investigate the classification of the cavernous segment of the internal carotid artery(ICA)curvature in patients with Knosp grade 4 pituitary adenomas and to evaluate its clinical significance in guiding endoscopic endonasal surgery.Methods Clinical data of 119 patients with pituitary adenomas treated via endoscopic endonasal approach,,including 74 with Knosp grade 4(grade 4 group)and 45 with Knosp grade 0(grade 0 group)as controls.The posterior bend angle of ICA was measured on preoperative sagittal MRI and classified as type A(<80°),type B(≥80°to 100°),or type C(≥100°).The posterior bend angles and ICA curvature types were compared between the patients with different Knosp grades.A generalized estimating equation(GEE)was applied to assess the association between ICA classification and the risk of incomplete tumor resection.Results All the 119 surgeries were completed successfully.The total tumor resection rate in the Knosp grade 4 group was 36.5%(27/74),significantly lower than that in the Knosp grade 0 group(86.7%,39/45)(P<0.05).Compared with the Knosp grade 0 group,the posterior bend angle of the ICA in the Knosp grade 4 group was significantly larger,and the proportion of Type C was significantly higher(both P<0.05).Among patients with unilateral Knosp grade 4,the posterior bend angle of the ICA on the grade 4 side was significantly larger than that on the contralateral(non-grade 4)side,and the ICA classification showed a significantly asymmetric distribution(both P<0.05).GEE analysis revealed that in patients with Knosp grade 4,the risk of incomplete resection was significantly higher for type A ICA compared to type C(OR=2.684,95%CI:1.190-6.055,P=0.017);the results remained consistent after adjusting for tumor size(OR=2.497,95%CI:1.085-5.750,P=0.032).Conclusions Compared with patients with Knosp grade 0,patients with Knosp grade 4 pituitary adenomas tend to have a larger posterior bend angle of the ICA.A smaller posterior bend angle with greater curvature of the cavernous segment may increase the difficulty of surgical resection,suggesting that ICA curvature classification could serve as a valuable reference for preoperative assessment and surgical planning.
Keywords：pituitary neoplasminternal carotid arterycavernous segmentKnosp gradetransnasal endoscopic surgery
Publication Date：2025-11-20
Online Publishing Date：2026-01-04(First online date of this platform, not the publication date of the document)
Pages：6( 643-648 )