Doctors conduct a surgery on a patient of COVID-19 in critical condition at a hospital in Wuhan, central China's Hubei Province, March 21, 2020. Doctors from Beijing, Jiangsu and other four different provinces have successfully completed the three-hour surgery on a male patient of COVID-19 in critical condition with joint efforts. (Photo by Ke Hao/Xinhua)

Doctors conduct a surgery on a patient of COVID-19 in critical condition at a hospital in Wuhan, central China's Hubei Province, March 21, 2020. Doctors from Beijing, Jiangsu and other four different provinces have successfully completed the three-hour surgery on a male patient of COVID-19 in critical condition with joint efforts. (Photo by Ke Hao/Xinhua)

Doctor Hu Ming gestures "OK" after completing a surgery on a patient of COVID-19 in critical condition at a hospital in Wuhan, central China's Hubei Province, March 21, 2020. Doctors from Beijing, Jiangsu and other four different provinces have successfully completed the three-hour surgery on a male patient of COVID-19 in critical condition with joint efforts. (Photo by Ke Hao/Xinhua)

Doctors conduct a surgery on a patient of COVID-19 in critical condition at a hospital in Wuhan, central China's Hubei Province, March 21, 2020. Doctors from Beijing, Jiangsu and other four different provinces have successfully completed the three-hour surgery on a male patient of COVID-19 in critical condition with joint efforts. (Photo by Ke Hao/Xinhua)

Chen Huaidong, a doctor from the Sir Run Run Shaw Hospital affiliated with the Zhejiang University School of Medicine, wears a protective suit before a surgery for a patient of COVID-19 in critical condition at a hospital in Wuhan, central China's Hubei Province, March 21, 2020. Doctors from Beijing, Jiangsu and other four different provinces have successfully completed the three-hour surgery on a male patient of COVID-19 in critical condition with joint efforts. (Photo by Ke Hao/Xinhua)

Surgeon Zhang Xichun (L) from Inner Mongolia medical team wears a protective suit to conduct a surgery on a patient of COVID-19 in critical condition at a hospital in Wuhan, central China's Hubei Province, March 21, 2020. Doctors from Beijing, Jiangsu and other four different provinces have successfully completed the three-hour surgery on a male patient of COVID-19 in critical condition with joint efforts. (Photo by Ke Hao/Xinhua)

Doctors conduct a surgery on a patient of COVID-19 in critical condition at a hospital in Wuhan, central China's Hubei Province, March 21, 2020. Doctors from Beijing, Jiangsu and other four different provinces have successfully completed the three-hour surgery on a male patient of COVID-19 in critical condition with joint efforts. (Photo by Ke Hao/Xinhua)