Microscopic anatomy study of transcortical-posterior lateral ventricular key-hole approach

Abstract

Objective To observe anatomical structures of the atrium of the lateral ventricle under microscope through the transcortical-posterior lateral ventricular keyhole approach and explore the feasibility of this method, so as to provide anatomical evidence for clinical application. Methods Both sides of ten adult cadaveric specimens were studied from September 2009 to May 2011. The transcortical-posterior lateral ventricular keyhole approach was performed into the atrium of the lateral ventricle. Ventricular system was exposed and internal structures were observed under microscope. The distance from the intersection of intraparietal sulcus and postcentral sulcus to cerebral longitudinal fissure, the depth of intraparietal sulcus and the distance from the bottom of intraparietal sulcus to lateral ventricle were measured. Results Several important structures were clearly observed through the transintraparietal-sulcus-posterior lateral ventricular keyhole approach. The floor was formed by the collateral trigone. Medial part of the anterior wall was formed by the crus of the fornix and the lateral part of the anterior wall was formed by the pulvinar of the thalamus. The medial wall was formed by two prominences that were located one above the other, the upper prominence called the bulb of the corpus callosum, and the lower prominence called the calcar avis. The lateral wall was formed by the caudate nucleus wrapping around the pulvinar. The choroid plexus of the the atrium of the lateral ventricle had one obvious prominence, the bulb of the choroid plexus. The choroid plexus extended laterally into the temporal horn of lateral ventricle and extends forward into the body of the lateral ventricles. The choroid plexus didn't expand to the occipital horn of lateral ventricle. Distance from the intersection of intraparietal sulcus and postcentral sulcus to cerebral longitudinal fissure was (35.36 ± 1.06)mm, the depth of intraparietal sulcus was (19.16 ± 1.03)mm, and the distance from the bottom of intraparietal sulcus to lateral ventricle was (21.31 ± 1.32)mm. Conclusions The transcortical-posterior lateral ventricular keyhole approach in operation can prevent pulling the cortex, reduce brain contusion, shorten the distance that reaches the ventricle, and expose anatomic structure of the atrium of the lateral ventricle clearly. Our study data can be used to locate intraparietal sulcus in operation and evaluate if the lateral ventricular is reached. This approach may be applied in operations of those lesions located in the rear of body of the lateral ventricles and the atrium of the lateral ventricle. Key words: Lateral ventricle; Posterior approach; Key-hole; Microscope; Anatomy