The authors report a rare case of an acute cerebral aneurysm rupture in a 
patient with a known factor XI deficiency. Aneurysmal subarachnoid hemorrhage 
(SAH) accounts for a high mortality and morbidity rate. When SAH is associated 
with an inherited coagulation disorder such as hemophilia C, an unexpected and 
possible increase in hemorrhagic stroke and increase in bleeding during surgery 
and in the postoperative period could lead to an extremely bad outcome. Clinical 
management consists of rapid correction of the coagulation disorder before 
undergoing any invasive intracranial procedure. Such an optimal therapeutic 
strategy must be under the care of a multidisciplinary medical and surgical 
team. Human factor XI concentrate (Hemoleven, Laboratoire Français du 
Fractionnement et des Biotechnologies [LFB], Les Ulis, France) was used 
successfully in this case report. New treatment using recombinant factor VIIa is 
discussed.