Department of Neurosurgery Xijing Hospital Fourth Military Medical University Xi'an 710032 China;
Neurosurgical Institute of PLA Xi'an 710032 China;
Department of Digestive Surgery Xijing Hospital Fourth Military Medical University Xi'an 710032 China;
Department of Statistics School of Preventive Medicine Fourth Military Medical University Xi'an 710032 China;
Department of Neurosurgery Xijing Hospital Fourth Military Medical University Xi'an 710032 China;
Department of Neurosurgery Xijing Hospital Fourth Military Medical University Xi'an 710032 China;
Department of Neurosurgery Xijing Hospital Fourth Military Medical University Xi'an 710032 China;
Department of Neurosurgery Xijing Hospital Fourth Military Medical University Xi'an 710032 China;
Department of Neurosurgery Xijing Hospital Fourth Military Medical University Xi'an 710032 China;