The mechanism of pathological changes of intraventricular hemorrhage in dogs.

BACKGROUND

Intraventricular hemorrhage (IVH) is an independent risk factor for both morbidity and mortality in patients with intracerebral hemorrhage and subarchnoid hemorrhage. The pathophysiological mechanisms by which blood within the ventricles causes brain damage are still poorly understood.

SETTINGS AND

DESIGN

We developed a canine (dog) model with long-term survival.

AIMS: To study the mechanisms of pathological changes associated with IVH.

MATERIALS AND

METHODS

The neurological status, cranial computed tomographic findings, and the pathological changes were studied in the dogs with IVH and also in the control dogs, intraventiricular saline injection.

RESULTS

In all the dogs in the control group there were no abnormalities in all the three parameters studied. The dogs in the IVH group developed neurological deficits after the blood injection. There was linear relationship between the ventricular volume and blood clot volume in the first week. After the first week, there was progressive enlargement of the ventricular volume, while the clots continued to shrink. There was complete lysis of the clots within 4 weeks. Pathological studies showed distruction of the ependymal lining of the ventricular system, subependymal gliosis and ischemia of the neurons in the subependymal areas, prominently around the aqueduct.

CONCLUSION

Ventricular dilation was the prominent feature following intraventricular injection of the blood. The other pathological features included disruption of ependymal lining, subependymal gliosis, and ischemic necrosis of neurons in the periventricular tissue of the third ventricle, aqueduct, and the fourth ventricle. These pathological may have some role in the ventricular dilatation following IVH.