Amongst his most notable students were Walton Lillehei, Christiaan Barnard, K. Alvin Merendino, Norman Shumway and Edward Eaton Mason.

After the veterinary physician recommended the slaughter of the family's 30 sows that could not farrow, Wangensteen missed three weeks of school to deliver over 300 piglets by manually extracting them.

[3][6] Encouraged by his father, Wangensteen attended the University of Minnesota where he obtained his BA, MB, MD, and PhD degrees.

Wangensteen was also able to spend time with Professor Leon Asher at the Physiological Institute in Bern, learning research techniques in basic science.

A year earlier, he tested and proved on an animal model, the hypothesis that it was swallowed air that caused the gaseous distension in the obstructed intestines.

[6] The technique became, and remains, standard practice for the initial management of small bowel obstruction in the context of previous abdominal surgery.

A major systematic review in 2008 demonstrated that the suction technique introduced by Wangensteen was successful in 65% to 81% of patients with small bowel obstruction without peritonitis, avoiding the need for surgery.

[10] For this innovative work the Academy of Surgery awarded him one of the highest American surgical honours, the Samuel D. Gross prize.

He used the Socratic method of teaching, making his trainees enquire, question and engage in dialogue to find answers to some of the most challenging surgical problems of the day.

[2] He was one of the first generation of full-time chairs of surgery in the US and was a pioneer of incorporating mandatory research into American surgical training programs.

These included F. John Lewis who in 1952, led the team which performed the world's first successful open-heart surgery using hypothermia, C. Walton Lillihei who introduced the technique of cross-circulation for open heart surgery, Richard DeWall who introduced the bubble-oxygenator style heart-lung machine,[15] and Frederick S. Cross who refined and popularized the rotating disk oxygenator.

Powerful backing from two of his early supporters Elias Potter Lyon, the former dean, and William J. Mayo prevented this from happening.

The aim of the forum was to "provide an opportunity to the younger surgical group for the presentation of the results of original clinical and experimental research".

[19] This brought together surgical trainees involved in research with one of the largest gatherings of surgeons in the world, encouraging communication and the sharing of ideas.

[2] Wangensteen hoped that it would also allow "a number of young, well trained surgeons their first opportunity of a hearing before a national surgery organization" and in that way improve their communication and presentation skills.

[19] The forum abstracts are judged on the basis of their originality, contribution to knowledge, the quality of the methodology, and impact and the best win the Excellence in Research Award.

[10] The suction technique for intestinal obstruction became so familiar to the general public that Ogden Nash, one of America's best-known entertaining poets who had experience of bowel surgery himself, incorporated it into a poem in 1951.

[1][22] A transcript of a series of interviews between Wangensteen and Peter Olch was issued in 1973 as part of the National Library of Medicine Oral History Program.