Meatball Surgery is the term used to describe the type of surgery performed by the doctors at the MASH units. The emphasis was on performing an adequate job at high speed as opposed to refinement and meticulousness. Writing to his father in the pilot episode of the M*A*S*H TV series, Hawkeye describes the process thus: "At this particular mobile army hospital, we're not concerned with the ultimate reconstruction of the patient. We only care about getting the kid out of here alive enough for someone else to put on the fine touches. We work fast and we're not dainty, because a lot of these kids who can stand two hours on the table just can't stand one second more. We try to play par surgery on this course. Par is a live patient."
The speed was necessitated by the sheer numbers of wounded which arrived. Rather than a steady stream of patients, a MASH could experience periods of relative inactivity such as seen in Season 2 "As You Were" to be followed by a surge of wounded arriving in the aftermath of a battle which would require the MASH staff to work without rest for days on end, as seen, for example in Season 3 "O.R.", Season 4 "Deluge" or Season 8 "Dreams".
The meatball style of surgery was unfamiliar to doctors working in the rear areas such as Tokyo. In Season 3 "The Consultant", Hawkeye and Trapper got to Tokyo for a medical conference and meet Dr. Anthony Borelli who asks why they aren't attending the lectures since some very fine doctors had come a long way to discuss new surgical techniques. Hawkeye and Trapper explain that in meatball surgery there was not much time for technique as speed is a priority. When Borelli observes that it must be challenging, they invite him to visit a MASH to "really get into the game". In the same way, when Winchester first arrives at the 4077th MASH, he is constantly harangued by the other surgeons for operating too slowly.
It was not that the MASH surgeons were unwilling to be innovative or go the extra mile. It all depended on whether time was available. In Season 7 "Inga", visiting Dr. Inga Halvorsen offers to demonstrate a new technique to repair a patient's hip so that he would not lose his mobility. Hawkeye and the other were willing to try it because it would only take an hour. In the same way, in "The Consultant" Henry was keen to try Dr Borelli's suggestion to attempt a novel technique of arterial repair rather than an amputation--it had to be done within 4-5 hours of the injury, so it had to be tried at the MASH or else it couldn't be done at all. (This is a historically accurate depiction of techniques of vascular repair which were pioneered by the MASH units during the Korean War.) Vascular repair would be featured in many other episodes after this, with the 4077th MASH even inventing and fabricating a new surgical instrument for the purpose in Season 6 "Patent 4077".
At other times, the press of time and the sheer numbers of wounded would force the MASH surgeons to do less than they might have in normal circumstances. In Season 8 "Heal Thyself" Hawkeye has to forego trying to reconstruct a patient's damaged artery. He tells Margaret there isn't time. "I save this leg, I lose that life." In a more extreme case, in Season 3 "O.R." Henry and Hawkeye decide not to operate on a patient because it would take two surgeons eight hours. There were more than a dozen others who desperately needed surgery and who might lose their lives while they were operating on him.