Abstract
Hydatid diseases are still endemic pathologies in developing countries which generally needs surgical treatment. The main aim of the treatment is total cyst evacuation without rupture. Dowling technique is preferable for this aim. There are various complications of hydatid disease surgery which include cortical collapse which is very serious and can be mortal. Our case was a 6-year-old boy diagnosed with a solitary isointense cystic mass in the left parietal region. There was no surrounding edema. The cyst was completely evacuated with Dowling technique without rupture. In about 10 min after evacuation, hemispheric cortical collapse occurred, and the patient developed cardiac arrest. Although cortical collapse is a rare complication, it can cause perioperative mortality. Special care and efforts should be taken as not to form large defects after cyst evacuation to prevent cortical collapse and related mortality.