Hemostatic thrombin-gelatin matrix leading to intracranial cyst formation : case report.

Local hemostatic agents has been used in neurosurgical field for many years; it is safe and efficient with no fatal complication reported in the literature. We routinely used gelatin-thrombin hemostatic agent (Floseal Hemostatic Matrix (Baxter Healthcare Corp, Fremont, CA, USA)) for hemostasis in minimally invasive endoscopic-assisted surgery for more than 500 intracerebral hemorrhage patients. However, two cases with sterile cyst formation were encountered. One received endoscopic hematoma evacuation, and the other had traditional craniotomy. Both cases received drainage of the cyst due to progressive enlargement and the mass effect they exert. We hypothesized that cyst wall may be formed by Floseal-induced fibrosis and inflammation, and the presence of check valve mechanism between the cyst and the ventricle which caused further dilation of the cyst. We reported this possible complication of local hemostatic agents.