New surgery shows early success
Short bowel procedure proves simple and effective

	The serial transverse enteroplasty, or STEP, procedure for short bowel syndrome. The bowel is stapled into v-shapes on alternating sides, decreasing its width and increasing its length. Children’s surgeons have found that food moves more quickly through the repaired bowel and that nutrients are absorbed more quickly.

Heung Bae Kim, MD, assistant in Surgery, never gave up on the good idea he had for improving the surgical outcomes of patients with short bowel syndrome (SBS). In fact, all he needed was a receptive audience, and a decade of thinking about the surgery quickly turned into finding a way to make it work.

SBS is a deadly disorder that can be caused by any of several diseases—most commonly, necrotizing enterocolitis (an infectious inflammatory disease of premature newborns), intestinal atresia (a failure of development of a portion of the intestine), and intestinal volvulus (which occurs when the bowel gets twisted and the blood supply is impaired). SBS can also be caused by surgical removal of part of the small bowel.

Regardless of the cause, the result is a widening of the remaining bowel, creating more surface area to absorb nutrients. This slows food digestion, breeds bacteria and can cause potentially life-threatening infections. In addition, patients with SBS must get their nutrients enterally delivered to the stomach or small intestine. In cases where this is not possible, patients have to get nutrition intravenously, which can cause liver failure and the need for a liver transplant.

Until now, SBS has been treated with a surgery called the Bianchi procedure, in which the bowel is bisected and one end is sewn to the other. In these cases, however, the bowel often re-dilates, leaving patients in the same condition as when they started.

Dr. Kim’s idea to avoid all of these difficulties was to staple v-shapes into alternating sides of the bowel, decreasing its width and increasing its length. “I thought it would work because it fulfills all of the requirements of an ‘ideal’ bowel lengthening procedure, in that it lengthens the bowel, tapers the dilated portions of the bowel, and doesn’t require any bowel removal,” says Dr. Kim. “It’s also a simple concept, and simplicity of design is important in surgery.”

He first shared his idea for the procedure with colleagues when he was in medical school 10 years ago, but it wasn’t until he drew the idea on the back of a napkin for Tom Jaksic, MD, PhD, associate in Surgery, that it finally struck a chord. The two surgeons performed animal studies in the lab and found that food moved more quickly through the small bowel and the nutrients were absorbed more completely, both of which lead to less bacterial growth and a decreased chance of infection. Drs. Kim and Jaksic dubbed the procedure serial transverse enteroplasty, or STEP.

After completing lab testing, the surgeons were ready to try it on a patient in need of immediate help, and Alex Malo was just such a patient. Born with gastroschisis—where a small hole in his stomach left four feet of intestines outside of his body—Alex underwent an unsuccessful Bianchi procedure in January of last year. Since Alex still had to get all of his nutrients intravenously, Drs. Jaksic and Kim needed to act quickly to prevent irreparable liver damage. They approached Alex’s family with the possibility of trying the STEP procedure. The family agreed, and in February 2002, Alex became the first person to have the STEP procedure. He has done very well since. “Before the surgery Alex was unable to get any nutrition enterally,” says Dr. Jaksic. “But now he gets 60 percent that way, and his liver is in perfect condition.”

Children’s surgeons have now performed the operation on additional patients, and while the Children’s patients who have undergone the procedure still receive much of their nutrition enterally, Dr. Kim says the hope is that one day they will all be able to eat food normally for the first time in their lives.

“The ultimate goal of any surgical procedure for short bowel syndrome is to improve a patient’s chances of becoming total parenteral nutrition independent,” says Dr. Kim. “Although we have not yet proven that STEP will achieve this goal we have shown that it can be performed safely and easily in circumstances where the Bianchi procedure can’t be performed for technical reasons. This offers another hope to children whose only other option would be a bowel transplant.”