Q: Is the STEP procedure right for me?

The STEP procedure is often brought up as a treatment for short gut syndrome. It's well-known by surgeons and patients alike. In many context, the procedure is described as a "bowel-lengthening" surgery because it's zig-zag cuts convert dilation into length, sparing intestinal surface that would otherwise be wasted when treating dilation.

But primarily the STEP procedure is a surgical treatment for dilation. This surgery has helped many people with short gut who develop dilated bowel loops. Studies show it can help increase nutrition absorbed through the gut, decrease the need for TPN ^1,2, and improve long-term survival ⁶. However, outcomes vary from person to person. Many people report incredible progress after surgery. Others didn't see the expected benefits, or even experienced complications and setbacks. The most common reported problem with the STEP procedure is that dilation can return. Less often, some patients experience gastrointestinal bleeding. Stenosis, a narrowing of the intestine, has also been reported. ³.

With mixed reports of success and failure, how can you know if this procedure is the right choice for you?

The following is a summary of information in currently published research and the experience of members of our online support group. It is not a substitute for advice from your medical team. I am not a clinician. Please discuss this information with your doctor as you consider what treatment path to follow.

A STEP procedure might be considered:

• when the intestine is dilated to at least 3.5 cm in a child or above 5 cm in an adult,^4,5,6
• after medical management such as dietary changes, bacterial overgrowth treatment, medication for motility, and treatment of strictures have failed,⁴
• to treat dilation that has developed over time and is causing problems, including bacterial overgrowth and d-lactic acidosis.^{4, 5}

A STEP procedure is not recommended:

• if the intestine is not dilated, or if dilation is less than 3.5 cm in a child or 5 cm in an adult, ^4,5,6
• if progress is being made with tube feeds and reducing TPN,⁴
• if medical management like dietary changes, medications, and treatment of strictures have not been tried or given time to work,⁴
• during early surgeries for short bowel syndrome like gastroschisis repair, atresia repair, or as a modification of other early surgeries,⁴
• in children younger than one year of age, whenever possible,^{4, 6}
• if the purpose of the surgery is simply to "create length" and not to treat dilation,⁴
• to treat dilation caused by a downstream obstruction.⁴

Repeating STEP procedures

In many cases, a second STEP procedure can be successful when redilation occurs. ^{6, 7, 8} Although there are no specific studies to support this observation, anecdotally, our group has observed more success with reSTEP procedures when patients have that second procedure performed at a center of excellence with an experienced surgeon.

Patients with a history of gastoschisis may experience less success due to dysmotility.^6,8

Ulcers and GI bleeding

After any gastrointestinal surgery, there is a risk that ulcers can form along surgical connections, sometimes months or even years after the surgery. These ulcers, known as anastomotic ulcers, are a potentially serious side effect of any GI surgery. However, because the STEP procedure uses so many incisions, this complication is of particular concern with this procedure, especially for those who are at greater bleeding risk.^{10, 11}

The causes of anastomotic bleeding are not entirely understood. Some suspected risk factors are:

• injury to the bowel from necrotizing enterocolitis (NEC), hirshprung's disease, intestinal atresia, volvulus, ¹¹ and/or gastroschisis,^{10, 11}
• unmanaged bacterial overgrowth,¹¹
• loss of the ileocecal valve (ICV), perhaps allowing damage to the gut from bile acids,¹¹
• genetic predisposition.¹¹

Again, these risk factors are not clearly understood. If a person has one risk factor, it does not necessarily mean they will develop ulcers. There is not yet sufficient understanding to predict who will experience bleeding.

When bleeding does happen can be difficult to diagnose and treat. While medication is often used to treat bleeding, in some cases, additional surgery to remove damaged bowel is needed.^4,11 This loss of bowel is a major setback for patients who already have short gut.

Alternatives to the STEP procedure

Though GI bleeding is not a complication for all patients, some find that risk unacceptable. We have heard of some surgeons who choose not to perform the STEP procedure. As the cited research here shows, those who are most familiar with the STEP procedure recommend caution in its use. There are some alternatives you could consider.

• If dilation is causing complications and limiting progress, the first steps should always be to attempt medical management. Diet modifications, gut rest, and medication management to treat bacterial overgrown and restore motility may improve symptoms and reduce dilation. ⁴
• If these treatment options fail and surgery is needed, surgical options that use fewer incisions such as tapering and ostomy-in-continuity could also be considered.
• When treating short gut syndrome, there is value seeking care from a center of excellence in treating intestinal failure. An intestinal rehabilitation program (IRP) can help to guide you through both medical and surgical management of dilation. Consulting with an IRP can allow a second opinion and also access to a more experienced medical team, including experienced surgeons.
• If circumstances do not allow for travel to another center, another option that is available for patients who live far from a center of excellence is to request that your physician submit your case to LIFT-ECHO, an online telehealth program for physicians where intestinal rehabilitation experts consult on cases from around the country. This is an opportunity for your local team to get guidance to help you from some of the best intestinal failure doctors in the country.

Final thoughts

The STEP procedure can be helpful when used appropriately to treat dilation. It does not yield the same benefits when used for bowel-lengthening alone. Surgery always comes at a cost. The incisions of the STEP procedure disrupt the normal movement of the bowel.⁴

Because the surgery is technically easy to perform, many surgeons may be willing to attempt it ⁵. However, anecdotal evidence suggest that small variables such as the size, position, and spacing of incisions can impact the procedure's outcome.

Our group has seen that STEP procedure has the best outcomes when performed by a surgeon who has done it many times. This is for two reasons: 1) an experienced surgeon will have more skill with the surgery, and 2) they will be better able to help evaluate if the procedure is appropriate and needed.

Any surgery on the intestines will affect their function. Intestines usually adapt better when they have been through less surgical trauma, even when that means working with a shorter length of intestine.⁴

When used appropriately, the STEP procedure is an effective surgical treatment option for dilation. However, it needs to be performed at the right time and in the right way, or the risks may outweigh the benefits.

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