I was asked to assist with a bilateral standard mastectomy (surgical removal of both breasts) for a patient with cancer in one breast. There were two surgeons: the senior attending surgeon, who was to remove the cancerous breast, and the senior resident, who was to remove the healthy breast.
What made the procedure particularly interesting was that the mastectomies were done simultaneously. I had the opportunity to compare the surgeons' techniques as they performed the identical procedure, side-by-side, at the same time.
Unsurprisingly, the more-experienced surgeon did a better job. He made better use of the tissue planes that separate the different layers of the body, making for a cleaner and safer surgery. He worked faster, his dissections were more elegant, and he nicked fewer arteries and vessels, meaning he let less blood. The end result looked nicer.
The experience raised a question that author Atul Gawande discussed at length in his excellent books Complications and Better: how much of a role should trainees should have in performing surgeries? Attendings tend to do a better job than residents at operating. But if residents weren't allowed to operate, how would they ever hone their skills and become attendings?