I recently saw a female patient six months after cerebral hemorrhage with cerebral angiography showing smoldering disease (Suzuki stage 4). The relevant literature was checked and the essence is as follows: 1. The lesion was bilateral internal carotid artery wills ring area artery involvement; 2. The peak age of publication was at 5 years and 40 years. The incidence is twice as high in women as in men. The incidence in Japanese children is 3 per 100,000; 3. It is estimated that two-thirds of patients have clinical progression after 5 years, while only 2 or 6% have progression after surgery according to a meta-analysis; 4. Some research centers recommend both direct bypass and indirect bypass – i.e., combined surgery.