Nineteen centers, including 2 from outside North America, submitted 1 to 10 patients each, for a total of 38 patients. The baseline patient characteristics are summarized in . Median age at STEP was 1.3 years (range 0 to 19.9 years), and median followup period from STEP procedure to most recent update, death, or transplantation was 12.6 months (range 0 to 66.9 months). Primary diagnoses in these patients are shown in and most frequently included intestinal atresia (n = 13), gastroschisis with or without volvulus (n = 11), and necrotizing enterocolitis (n = 7). Three patients undergoing the STEP procedure had previously undergone intestinal lengthening and tapering using the method described by Bianchi.14
Interestingly, one patient underwent a successful STEP procedure after previously having an attempted Bianchi procedure that was aborted because the bowel was noted to be nonuniformly dilated at laparotomy.
Select Characteristics of 38 Patients Undergoing Serial Transverse Enteroplasty
Distribution of primary diagnoses in 38 patients undergoing the serial transverse enteroplasty procedure.
Indications for the STEP procedure included SBS with dependence on parenteral nutrition (n = 29), bacterial overgrowth in the setting of SBS (n = 6), and neonatal atresia with marginal residual bowel length (n = 3). The median age at STEP for each of these indications was 1.2 years (range 1 month to 19.9 years), 13.9 years (range 2.0 to 19.6 years), and 3 days of life (range 0 to 4 days of life), respectively (p < 0.05, Kruskal-Wallis test). Primary diagnoses in the 29 patients with SBS included intestinal atresia in 11, gastroschisis with or without volvulus in 9, necrotizing enterocolitis in 4, Hirschsprung disease in 2, segmental volvulus in 2, and malrotation with volvulus in 1. Of the six patients with bacterial overgrowth, three had necrotizing enterocolitis and one each had intestinal atresia, malrotation with volvulus, and congenital shortened bowel. Finally, of the three neonates with obstruction, two had gastroschisis with volvulus and atresia and one had pure intestinal atresia.
All patients experienced some degree of intestinal lengthening and tapering. In patients with operative measurements, pre-STEP intestinal length ranged from 12 cm to 190 cm; post-STEP length ranged from 18 cm to 325 cm. Overall, mean intestinal length increased considerably, from 68 ± 44 cm to 115 ± 87 cm (n = 27, p < 0.0001; ). This represented a relative 69% increase in overall small intestinal length. Likewise, mean intestinal width was considerably tapered by the STEP procedure, from 6.3 ± 3.9 cm to 2.1 ± 0.9 cm (n = 30, p < 0.0001), representing a relative three-fold tapering of the dilated intestinal diameter. Pre-STEP intestinal width ranged from 2 cm to 24 cm; post-STEP width ranged from 1 cm to 5 cm.
Graphic representation of the increase in intestinal length after the serial transverse enteroplasty (STEP) procedure in 27 of the 38 patients.
For patients in whom the STEP procedure was performed for SBS with dependence on parenteral nutrition, the percentage of total calories tolerated enterally increased from 31% ± 31% to 67% ± 37% of calories (n = 21, p < 0.01) at a median followup of 12.6 months (). This represented an overall post-STEP increase in enteral tolerance of 116% relative to pre-STEP baseline. This analysis excluded neonates and patients who progressed to transplantation or death. Ten of these 21 patients are now completely weaned from parenteral nutrition. Of three patients who had a decrease in enteral tolerance after the STEP procedure, two patients are in the early postoperative period and are expected to increase their enteral tolerance, and one has had a slight decrease and plateau of his enteral tolerance, now at 37 months followup ().
Figure 3 Graphic representation of the change in tolerance of enteral calories for 21 short bowel syndrome patients undergoing the serial transverse enteroplasty procedure, based on length of followup. The increase in mean enteral tolerance from 31% to 67% of (more ...)
Of the six patients who underwent the STEP procedure for bacterial overgrowth, five have experienced complete resolution of their symptoms. One patient who had neurogenic anorectal incontinence is still having diarrhea but is reported to have a better quality of life, with improved bowel control. Of the three neonates who underwent the STEP procedure, two are currently tolerating 100% and 80% of their calories enterally. Progressive liver failure developed in the third and was referred for liver and small intestine transplantation, but died after the family elected not to pursue transplantation.
Complications related to the STEP procedure include those that occurred intraoperatively, those that occurred within 30 days postoperatively, and late complications occurring more than 30 days postoperatively (). The majority of complications occurred in patients with SBS, most likely because this cohort represented the vast majority of the patients.
Complications Arising after the Serial Transverse Enteroplasty Procedure in 38 Patients
Two intraoperative complications were noted. One was a leak at the apex of a staple line, which was immediately identified and repaired in two patients with SBS. The second was aspiration of gastric contents on induction of anesthesia in one patient, also with SBS. This occurred despite venting of a preexisting gastrostomy tube before induction of anesthesia and resulted in a prolonged intensive care course for respiratory insufficiency. This patient subsequently experienced progressive liver failure and received a multivisceral transplant.
Five postoperative complications were noted. Two patients—one with SBS and one with bacterial overgrowth—experienced postoperative bowel obstructions. Both resolved successfully with expectant management and both patients had free passage of contrast on subsequent upper gastrointestinal series. The other four postoperative complications occurred once each in four different patients with SBS. Hypertension of unknown etiology developed in one patient after the procedure and is maintained on antihypertensive medications; the relationship of this condition to the operation is unclear. Finally, in one patient an intraabdominal abscess developed, in one patient an intraabdominal hematoma developed, and in one patient a serous pleural effusion developed. All three of these patients were managed using temporary, radiologically placed drainage catheters with full resolution and no additional sequelae.
The only late complications were the need for intestinal or multivisceral transplantation and mortality. Transplantation was required in three patients (7.9%), all with SBS, who experienced progressive liver failure despite the STEP procedure. Two other patients have been referred for transplantation because of ongoing feeding intolerance and progressive liver disease. One patient underwent a multivisceral transplantation, and the remaining four underwent or have been listed for a combined liver and intestine transplantation. Three other patients, who had previously been listed for liver and intestine transplantation, have been removed from the transplant list because of steady improvement in their enteral tolerance post-STEP.
Mortality occurred in three patients (7.9%): two with SBS and the neonate described previously. In all three patients, the cause of death was progressive liver failure and sepsis. All three were referred for transplantation before death. Two died while awaiting transplantation. The neonate, as discussed, died after being removed from the transplant list at the request of the family.