This is the 8490th most frequent Japanese word.
手術
Surgery.
Here, '手術' means 'surgery' as a medical procedure, specifying the heart as the target.
医者は昨日心臓の手術を行いました。
The doctor performed heart surgery yesterday.
'手術' in this sentence refers to 'surgery' as something one undergoes, discussing deliberation around the decision.
手術を受けることについて考えています。
I am considering undergoing surgery.
In this case, '手術' indicates multiple surgical procedures generally, focusing on quality and improvements in technique.