The lateral ventricle, located deep within the intracranial space, poses significant surgical challenges due to its complex anatomy and proximity to critical neural structures. The purely endoscopic posterior interhemispheric approach, leveraging the natural corridor of the interhemispheric fissure, offers a promising alternative. A retrospective review was conducted on 23 cases of lateral ventricle lesions treated with the purely endoscopic posterior interhemispheric approach between January 2013 and December 2024. Whether an ipsilateral or contralateral approach was chosen was based on lesion characteristics to optimize exposure. Surgical procedures were performed under general anesthesia and utilizing bimanual endoscopic techniques. Total resection was achieved in 21 cases (91.3%), and subtotal resection in 2 cases (8.7%). The endoscopic approach significantly enhanced the operative working range, with ipsilateral access improving anteroposterior exposure and contralateral access expanding lateral exposure. Postoperative complications included intracranial infection (1 case), intraventricular hemorrhage (1 case), and unilateral hydrocephalus (1 case), all of which were managed successfully with no surgery-related mortality. The purely endoscopic posterior interhemispheric approach is a safe and effective minimally invasive treatment for selected lateral ventricular lesions. It significantly expands operative working ranges, offering a valuable addition to neurosurgical practice.

Endoscope; Endoscopic neurosurgery; Interhemispheric approach; Lateral ventricle; Precuneus.

Declarations. Ethical approval: This study was conducted in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. All procedures performed in studies involving human participants were approved by the Ethics Committee of Fudan University Zhongshan Hospital. Consent to participate: Informed consent was obtained from all individual participants included in the study. Confidentiality and privacy of patient data were strictly maintained throughout the research. Consent to publication: The authors affirm that human research participants provided informed consent for publication of the images in all figures included. Competing interests: The authors declare no competing interests.