OBJECTIVETo evaluate the risk factors and study the methods of prevention and treatment for the ruptures of aneurysms in keyhole minimally invasive approaches.

METHODSFrom 1999 to 2005, 115 cases of intracranial aneurysms were divided into 2 classes according to the risk factors of aneurysm rupture. Forty-three cases of lower risk underwent microsurgical procedures as keyhole approaches, including pterional approach in 20 cases, supraorbital approach in 18 cases, interhemispheric approach in 5 cases. Seventy-two cases, rest of microsurgical procedures, were performed as conventional craniotomy, including pterional approach in 31 cases, supraorbital approach in 11 cases, interhemispheric approach in 7 cases, pterional-supraorbital in 10 cases, pterional-interhemispheric in 6 cases, supraorbital-interhemispheric in 4 cases, pterional-supraorbital-interhemispheric in 3 cases.

RESULTSSix aneurysms leaked and 3 ruptured (rupture rate 7.0%) treated with keyhole approaches during operations. No one died by keyhole approaches. Eighteen aneurysms leaked and 9 ruptured (rupture rate 12.5%) treated with conventional approaches during operations. Two patients died by conventional approaches.

CONCLUSIONSKeyhole approaches as a time-saving, trauma-reducing procedure could improve the postoperative outcomes, but these approaches still exist probability of aneurysm rupture. It is possible that keyhole-bone flap becomes a limitation to deal with huge or ruptured aneurysms. And it is important to make a specially preventive strategy for aneurysm rupture.