Introduction: Several studies have investigated the vasculature of each segment of internal capsule whereas a few have addressed the variations. In this study the entire blood supply of internal capsule was studied through microscopic evaluation of sections of brains that previously had received selective vascular die injections.
Methods: This project involved a prospective study of deceased adult man and woman without a known neurologic history. In each case, prior to brain removal, cerebral vessels were flushed with saline. Following brain removal and fixation in 10% buffered formalin, cerebral vessels were isolated and cannulated for die injections bilaterally: anterior, middle and posterior cerebral arteries, anterior choroidal and posterior cerebral arteries.
The cerebrum was then cut in the horizontal plane at 0.5 cm thickness using an electric meat slicer. Tissue blocks including the entire internal capsule were selected for standard tissue processing, paraffin embedding and microtomy. Ten micrometer thick sections were obtained for observation of injected vessels in the internal capsule, using a light microscope. Using a range of 4x to 20x magnifications each vascular territory was then marked on the unstained slides based on observation of specific dyes. A spreadsheet algorithm was used to calculate the area for each vascular distribution.
Results: The variability in vascular territorial distribution of the IC was successfully demonstrated in detail by this technique.
Conclusions: Arterial supply of the IC was found to be very variable in this study. This novel technique has provided very reliable preliminary data demonstrating this variability.
Patient Care: Better understanding of the cerebral vasculature will help neurosurgeons formulate appropriate treatment plans for cerebrovascular pathologies.
Learning Objectives: Utilize a novel technique to provide reliable data demonstrating arterial blood supply variations of the IC.