Visualization of pressure related vessel compression in the perihemorrhagic zone during endoscopic ICH evacuation

The existence of perihemorrhagic ischemia in intracerebral hemorrhage (ICH) has been subject to intense debate. In contrast, the concept of reduced cerebral blood flow (CBF) in the perihemorrhagic zone (PHZ) is widely accepted. This report aims to demonstrate preliminary experience with endoscopic visualization of perihemorrhagic vessel compression in patients with ICH.

Endoscopic findings in the PHZ during minimally invasive hematoma evacuation in six patients with basal ganglia ICH are described. 3D-Neuronavigation for exact real-time orientation and a translucent working channel for tissue visibility are used.

While entering the hematoma with the endoscope, the same distinct areas are illustrated in five patients: In the cortical entry zone, uncompressed vessels are present. In the subcortical white matter, vessel quantity shows its physiological rarification. In perihemorrhagic white matter adjacent to the ICH however, vessels appear to be almost completely absent. After hematoma-evacuation, the lack of vessels in the PHZ vanishes and in contrast, correlates of hyperperfusion are observed. Occurrence of these findings does not show correlation with clinical or radiological parameters. However, the only patient without vessel compression in the PHZ had the best neurological outcome in this small case series.

We present visual correlates of mechanical vasoconstriction due to tissue compression in the PHZ of patients with basal ganglia ICH. Removal of the hematoma leads to visible reperfusion of the PHZ. These findings may help to understand the perihemorrhagic pathophysiology associated with focal reduction of cerebral blood flow and possibly ischemic changes in ICH.