1. Ricardo A. Caicedo, M.D. Pediatric Gastroenterology
Short Bowel Syndrome
Ricardo A. Caicedo, M.D.
Pediatric Gastroenterology

2. Definitions Short bowel syndrome (SBS) Intestinal failure
Functional impairment resulting from critical reduction in intestinal length
Includes malnutrition, chronic diarrhea, malabsorption, growth failure
The most common cause of…
Intestinal failure
Severely compromised intestinal function of any etiology (irrespective of bowel length)
Total parenteral nutrition (TPN)-dependent

3. About 20 % of infants with NEC requiring resection develop SBS
Etiology: Neonates
- Gastroschisis
- Omphalocele
- SB atresias
Volvulus
Malrotation
Other
Thrombosis
Aganglionosis
About 20 % of infants with NEC requiring resection develop SBS

4. Etiology: Children/Adolescents
Volvulus
Trauma
Intra-abdominal cancer
Vascular anomalies
Radiation enteropathy
Overall Incidence 1:500,000

5. Prognostic Factors SB length Absorptive function of residual SB
Normal FT infant: cm
Loss of >70% (residual SB length < 70 cm in infants) portends SBS
Absorptive function of residual SB
Proportion of daily calories tolerated enterally
Intestinal adaptation
Compensatory events stimulated by massive bowel resection
Anatomy of resection
Loss of segment-specific functions
Loss of ileocecal valve

6. Anatomic Considerations
Loss of segment-specific functions
Jejunum: primary site of digestion and absorption
Ileum: B12 and bile acid absorption
Colon: water absorption and adjunctive carbohydrate absorption
Ileo-cecal valve
Regulation of intestinal transit
Prevention of bacterial reflux into SB

7. Management: Postoperative Period
Maintenance of fluid/electrolyte balance
Maintenance TPN
Separate IVF for ostomy output replacement
H2-blocker to tx gastric hypersecretion
Await resolution of postoperative ileus

8. Enteral Feeding
Initiated when postop. Ileus resolved, UGI tract decompressed, and F/E/N status stable
Advancement of EN and reduction/elimination of PN is the goal
Promotes intestinal adaptation
Follow hydration status, stool output, body growth, labs (albumin, prealbumin, Hb, BUN)
Continuous tube feeds: decrease SB osmotic load and absorptive workload per unit of time

9. Enteral Feeding Composition
Protein
Breast milk: promotes adaptation
Hydrolysate (semi-elemental): peptides more easily assimilated in short gut
Amino acid (elemental): prevention of milk protein hypersensitivity
Higher osmolarity
Fats
MCT do not required bile acids/micelle formation for absorption
Excess of MCT can lead to EFA deficiency
Carbohydrate
CHO malabsorption is the rate-limiting factor in advancing EN
Glucose polymers digested more efficiently than lactose
Start with dilute formula
increasing in volume before increasing energy density OR
Increasing in concentration before increasing rate
Monitor stool output, pH, reducing substances

10. Advancement of EN Supplements Cycle/window and wean TPN
Vitamins ADEK, B12
Electrolytes: Na/K citrate, Ca, Mg
Elements: Fe, Zn
Cycle/window and wean TPN
Increase EN at avg. rate of cal/kg q 1-3 days
Non-nutritive sucking and PO feeding to prevent oral feeding aversion
Intolerance of EN but stable: home TPN

11. Predicting Ability to Wean TPN
Length of residual SB
Percent daily enteral intake
Earlier restoration of intestinal continuity
Fewer complications
Biomarkers: experimental stage
Urine 3-0-methylglucose after PO feeding (rat model)
Plasma citrulline levels (adult SBS pts)
< 20 umol/L predict permanent intestinal failure

13. Complications TPN-related CVL-related SB bacterial overgrowth
Cholestasis/hepatopathy
Calcium-bilirubinate gallstone disease
CVL-related
Infection- bacterial or fungal sepsis
Thrombus/thromboembolism
SB bacterial overgrowth
Nutrient deficiencies
Enterocolitis
Mechanical or pseudo-obstruction (dysmotility)
Pancreatitis
Nephrolithiasis (oxalate stones)

14. Prevention of TPN Liver Disease
Reduce TPN/advance EN
Cycle TPN (run < 18 hrs/d)
Monitor TPN composition
Glucose infusion rate < 8-12 mg/kg/min
Keep AA at 2.5 g/kg/d
Keep lipids at < 40% of total caloric intake
Reduce trace elements (Mn, Cu) to 25% RDA once cholestasis develops
Manage CVL infection and SBBO
Start UDCA at mg/kg/d

15. SB Bacterial Overgrowth
Factors
Dysmotility/poor peristalsis leading to stasis of enteral contents
Loss of ICV
Symptoms
Feeding intolerance, abd. distention, weight loss, blood in stools
D-lactic acidemia: lethargy, ataxia, WAGMA
Diagnosis
Duodenal fluid aspirate and culture (> 105 col/ml)
Breath hydrogen test
Often made on clinical grounds
Treatment
Empiric antibiotics (metronidazole, TMP-SMX, PO gentamicin, amox-clavulonate, rifaximin)
Adjunctive probiotics: little evidence, and a safety concern in SBS pts esp. those with CVL

16. Medical Therapies Anti-motility agents Glutamine/GH
Loperamide, diphenoxylate/atropine
Slow transit time
Improve fluid absorption and reduce fecal fluid loss
Bile acid binder (cholestyramine)
Prevents bile acid malabsorption and bile acid-induced secretory diarrhea
Octreotide: reduces output from proximal enterostomies
Glutamine/GH
Mostly theoretical/animal or transient benefit
GLP-2: may stimulate mucosal growth and reduce secretions; still experimental

17. Surgical Interventions
Longitudinal tapering
Bianchi lengthening operation
Doubles length, reduces diameter by 0.5
preserves effective surface area

18. Serial Transverse Enteroplasty (STEP)
Creates a maze-like tunnel within dilated segment
Kim HB et al, J. Pediatr Surg. 2003; 38:881-5.

19. SB Transplantation Indications (Am. Soc. Transplantation, 2001)
Progressive/irreversible TPN liver disease (~ 4% of infants w/SBS)
Cholestasis beyond 3-4 mos of age
Features of PORTAL HTN
Impaired synthetic function (albumin, INR)
Recurrent sepsis
Threatened loss of central venous access
Contraindications
Absolute: AIDS, overwhelming sepsis
Relative: weight < 5 kg, multiple previous abdominal operations

20. Survival Overall: 80-94% Mortality higher in patients with NEC
Very long term (up to 25 y) TPN: 94% survival
Transplantation
Mortality is center-specific
Largest experience: U. Pittsburgh (Reyes J, Semin Pediatr Surg 2001)
1-yr survival rate: 70%
3-yr, all ages combined: 55%
Mortality greater in
Patients under 2 y of age
Combined SB-liver tx
Higher risk of PTLD in SB transplantation