[译] 冠状动脉架桥术是一项大手术。
[误] Coronary bypass is a large operation.

[正] Coronary bypass is a major operation.
[注] 医学上"大手术"用major operation;"小手术"用minor operation。如：Appendectomy is a mere minor operation 阑尾截除术只是一项小手术。