Serial Transverse EnteroplastyEdit

Serial transverse enteroplasty

Serial transverse enteroplasty (STEP) is a surgical technique used to lengthen the small intestine in patients with short bowel syndrome or other forms of intestinal failure. By creating a series of alternating, zigzag incisions along the anti-mesentery border and stapling them to form a longer, slender channel, STEP increases the usable length of bowel without removing intestinal tissue. The result can be greater absorptive surface area and, for some patients, a reduced or reversed dependence on parenteral nutrition. While STEP is most commonly described in pediatric populations, it has also been applied in adults with complex intestinal failure. For context, STEP is one of several intestinal lengthening strategies, alongside the longer-standing Bianchi procedure (longitudinal intestinal lengthening and tailoring) and other approaches that aim to optimize absorptive capacity while preserving as much bowel as possible. See short bowel syndrome and Longitudinal intestinal lengthening and tailoring for related concepts.

History

The idea of physically altering the configuration of the remaining bowel to increase length emerged as clinicians sought alternatives to resection in patients with extensive bowel loss. STEP was described and popularized in the late 1990s and early 2000s, particularly within pediatric surgical centers that manage long-term intestinal failure. The technique rapidly became part of the armamentarium for selected patients, with growing experience documenting its feasibility, safety, and potential benefit. For readers interested in broader historical context, see Bianchi procedure and intestinal lengthening.

Indications

STEP is considered for patients with short bowel syndrome or other forms of severe intestinal failure in whom

the bowel length is insufficient to sustain adequate nutrition on its own, and
there is a reasonable expectation that novel configuration will improve nutrient absorption and/or tolerance of oral or enteral feeds, potentially reducing or eliminating dependence on parenteral nutrition.
the bowel tissue and blood supply are suitable, and the patient can tolerate a major abdominal operation.
the expected quality of life and growth (in children) or functional status (in adults) would improve with greater enteral autonomy.

Indications are often determined by a multidisciplinary team including surgeons, gastroenterologists, nutritionists, and, in children, pediatricians and developmental specialists. STEP is typically used after prior bowel resections or congenital short bowel conditions, and it may be considered after other lengthening strategies, depending on anatomy and clinician judgment. See short bowel syndrome for broader clinical context.

Procedure

The STEP operation is performed through an open or laparoscopically assisted approach. Key elements include:

Identification of a segment of bowel with preserved viability and mesenteric blood flow.
Creation of a series of transverse incisions along the anti-mesentery border, with careful spacing to avoid compromising the mesenteric vessels.
Serial stapling of the incisions to generate a longer, serpentine channel that effectively increases the overall length of usable bowel while maintaining lumen continuity.
The staged or single-session approach depends on the patient’s condition, anatomy, and the surgeon’s assessment of risk and benefit.

The aim is to lengthen the bowel without sacrificing length, while avoiding strictures or kinking that could impair flow. The procedure preserves most of the existing bowel and relies on the bowel’s inherent adaptive capacity to absorb nutrients as the configuration changes. After STEP, patients typically undergo careful postoperative monitoring, with ongoing nutritional management and gradual advancement of enteral feeding as tolerated. See parenteral nutrition for related management considerations.

Outcomes

Evidence from centers that perform STEP shows that many patients experience improvements in nutritional autonomy and reductions in the volume or duration of parenteral support. Outcomes vary with age, underlying condition, length of remaining bowel, and center expertise. Some patients achieve meaningful enteral tolerance and growth, while others require additional interventions or remain dependent on parenteral nutrition. Complications are possible and may include transient or persistent bowel obstruction, anastomotic or staple line issues, strictures at the incis—lines, or vascular concerns related to mesenteric blood supply. As with other complex bowel-lengthening procedures, long-term follow-up emphasizes nutrition, growth (in children), and quality of life. See parenteral nutrition and intestinal adaptation for related concepts.

Complications and controversies

Complications can include anastomotic leaks, stenosis at staple lines, bowel obstruction from adhesions or kinking, and, less commonly, ischemic injury to bowel segments. These risks underscore the need for careful patient selection, meticulous surgical technique, and experienced postoperative care.
The evidence base for STEP is largely derived from case series and cohort studies rather than large randomized trials. This has fueled ongoing discussion in the surgical community about which patients are most likely to benefit, how to measure success, and how STEP compares to other lengthening strategies in different clinical scenarios.
Some clinicians emphasize the importance of preserving as much native absorptive surface as possible and argue that STEP’s benefits depend heavily on patient-specific anatomy, such as residual bowel length and the capacity for mucosal adaptation. Others point to the role of multidisciplinary care, including optimized nutrition and gradual enteral advancement, as essential to any successful outcome.
Debate exists regarding the relative merits of STEP versus alternative approaches like the Bianchi procedure, with centers often choosing based on anatomical suitability and surgeon experience. See Longitudinal intestinal lengthening and tailoring and Bianchi procedure for comparable strategies and historical context.