2. Recent advances - Small Bowel
Transplant
Presenter - Dr Kruti Pendyala
Moderator - Dr Arshad K
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3. Contents :
- History
- Intestinal failure - Causes, indications of SBT
- Recipient and Donor assessment
- Types of transplants
- Process of organ procurement, surgical procedure
- Advances
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4. History -
• Intestine transplantation has become a lifesaving
treatment option for patients with intestinal failure.
• 1967( Lillehei and coworkers) → TPN → increased
cases of PNALD → Cyclosporine immunosuppression
→ 1988, first successful human SBT.
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5. Intestinal failure:
• When a patient is unable to maintain satisfactory fluid,
electrolyte or nutritional homeostasis without intravenous
administration
• Intestinal Failure can occur due to:
- inadequate intestinal length (“short bowel syndrome”)
or
- function that prevent adequate nutrient absorption.
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8. Indications for small bowel transplant -
- include irreversible intestinal failure and one or more of the following:
- (1) overt or impending liver failure caused by PNALD;
- (2) Limited central venous access;
- (3) multiple episodes of catheter-related infection requiring hospitalization in
any year;
- (4) single episode of fungal line infection;
- (5) frequent and severe episodes of dehydration, despite intravenous (IV) fluid
supplementation and TPN.
- (6) diseases for which no alternative therapy is available (such as complete
splanchnic venous thrombosis and unresectable benign or slow-growing
mesenteric tumors)
10. Donor Evaluation :
- compatible blood type
- ideal donor should have a body weight 50% to 75% that of
the recipient
- cold ischemia time - less than 6hours
- viral serologic testing of the cadaveric donor for Epstein-
Barr virus (EBV) and cytomegalovirus (CMV)
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11. • Contain all or part of the donor
jejunoileum.
• The jejunum is stapled past the
ligament of Treitz.
• SMA and SMV are used as the vascular
pedicles at the root of the mesentery.
• SMA can be lengthened to include a
cuff of aorta and the SMV can go up as
far as the portal vein (PV)
Types of transplant
1. ISOLATED INTESTINE GRAFTS
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13. 2. Small intestinal and colon transplant
• Organs included: Small intestine and colon
(+/- pancreas)
• Proximal enteric anastomosis: Duodenum or
proximal jejunum
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14. • The jejunum is stapled past the ligament of Treitz
• SMA and SMV are used as the vascular pedicles at the
root of the mesentery
• Indications:
⮚Intestinal failure that cannot be managed on total
parenteral nutrition
⮚Mild to moderate liver dysfunction due to total
parenteral nutrition
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https://youtu.be/BSQYcrVE1vE?si=WFOixFZAwJbe3OQb
15. 3. Liver and small bowel
transplant
• Organs included: Liver, pancreas,
small intestine and colon
• Extent of resection: Liver, small
intestine and part of colon
• Proximal enteric anastomosis:
Duodenum or proximal jejunum
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16. • The duodenum is stapled off distal to
the pylorus, the pancreas is left wholly
intact for biliary drainage, and the
entire jejuno-ileum is mobilized and
controlled
• The vascular pedicles of a common
aorta/celiac/SMA trunk and an intact
donor PV and bile duct
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17. • Indications:
⮚Intestinal failure and advanced, irreversible liver
failure due to total parenteral nutrition
⮚Intestinal failure due to a hypercoagulable state
associated with enzyme deficiencies that can be
corrected by a liver graft. Eg: mesenteric vascular
thrombosis secondary to protein C or S deficiency
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18. 5. Multivisceral transplant
• Organs included: Liver, stomach,
pancreas, small intestine and
colon
• Extent of resection: Liver,
stomach, pancreas, small intestine
and part of colon
• Proximal enteric anastomosis:
Proximal stomach or oesophagus
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19. • The stomach is most commonly
included in this allograft type. During
the procurement operation, rather than
dividing at the level of the pylorus, the
esophagus is transected above the GE
junction
• Vascular inflow is the same as
described above for the L-ITx graft
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20. • Indications: Intra Abdominal tumors with local
invasion, and require resection of multiple
abdominal organs (evisceration) for surgical cure
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21. 4. Modified multivisceral
transplant
• Organs included: Stomach,
pancreas, small intestine and
colon
• Extent of resection: Stomach,
pancreas, small intestine and part
of colon
• Proximal enteric anastomosis:
Proximal stomach or oesophagus
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22. Process:
• Small bowel transplants can be done using either cadaveric
(brain dead) or living donors
• Combined bowel-liver or multivisceral transplants only from
cadaveric donors
• Donor and recipient operations occur simultaneously; to
minimise cold ischemia time (<6 hours)
• Organs are retrieved en bloc
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23. • Arterial inflow:
✔From infrarenal aorta
✔Donor thoracic aorta used as an arterial conduit to
which the donor aortic patch with coeliac artery and
SMA is anastomosed
✔Intestine only grafts: Inflow is from SMA;
anastomosed to the aorta or to the recipient SMA or
using a conduit from donor iliac vessels
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24. • Venous outflow:
✔Liver containing graft: Venous outflow is via
hepatic veins and IVC
✔Non-liver containing grafts: Venous outflow is via
the portal vein; draining into the systemic
circulation (IVC) or the portal circulation
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25. • Enteric anastomosis
✔ Proximal enteric anastomosis: Oesophago-gastric,
oesophago-jejunal, gastro-gastric, gastro-jejunal or
jejuno-jejunal
✔ Distal stoma or primary distal anastomosis with
covering ileostomy
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26. Recepient operation:
• Preoperative mapping with a magnetic resonance
venogram (MRV) is usually performed during the initial
evaluation
• Guides the anesthesiologist during CVC placement
• Central access above the diaphragm is usually necessary
both because of substantial blood loss encountered during
the organectomy in a hostile abdomen and also because
large-bore peripheral IV access is generally not possible in
these patients
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28. Indications
• Nowadays, SBT is not indicated for patients who are
dependent on parenteral nutrition, having no complications.
• Indications for STB are thrombosis of two of the six major
venous accesses, episodes of catheter-related infections
(two or more per year, fungemia, shock, or respiratory
failure), liver disease, alterations of growth and development
in children, and refractory electrolyte changes.
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29. • Patients with mild liver disease, revealing no signs of portal
hypertension and mild hepatic fibrosis on liver biopsy, may
receive an isolated intestinal graft and do not need a liver
graft transplantation.
• Independent predictors of PNALF were, in descending order,
total bilirubin level, platelet count, and albumin level.
Predicted probabilities of eventual LF to 83% to 84% when
the total bilirubin level was 11.7 mg/dL, platelet count was 168
x 103/μL, and albumin level was 3.0 g/dL.
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30. Surgical technique
• In patients with mild portal
hypertension, venous drainage of the
isolated small bowel - into the vena
cava.
• To observe the bowel
endoscopically, ileostomy is
performed in all types of SBTs.
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31. • Recent studies - inclusion of the colon does not increase
morbidity, mortality, and bloodstream infections, (8).
• Loss of abdominal flexibility in patients- difficult primary
abdominal wall closure, tissue expanders, staged abdominal
closure with mesh, bioengineered skin equivalents, acellular
dermal matrix, vascularized or nonvascularized rectus muscle
fascia grafts, skin grafts, and vascularized abdominal wall
transplantation from the same donor (12, 13).
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32. Donors Preparation
• Donors ideally should be younger than 55 years and under no or
low dose of vasoactive drugs (below 5μg/kg/min of dopamine).
• Cytomegalovirus-seropositive donors are accepted. Ganciclovir
• The mucosa of the small bowel is very sensitive to ischemic injury.
Infection-related mortality rate is higher and the absorptive function
is lower if the intestinal graft is taken from circulatory death donars.
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33. • Living donor SBT is a relatively recent type of
transplantation, which is suitable especially for children with
small bowel failure in whom acute decompensated hepatic
failure occurs. To decrease the morbidity and mortality while
waiting on the list, living donors can be used successfully.
• Intestinal grafts contain 150 cm of ileum with or without a
left lateral liver graft depending on the liver function of the
patient.
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34. Organ Preservation
• The University of Wisconsin (UW) solution is considered the gold
standard for the preservation of all organs of the abdomen.
• Celsior and HTK, give results similar to those by the UW solution
during ischemic periods up to 8 h in SBT.
• On comparing UW and HTK, results for graft survival, initial function,
endoscopic appearance, and rate of transplant pancreatitis were found
to be similar. HTK gives the advantage of better flushing of the
microvasculature due to its low viscosity (17)
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36. Postoperative Management and Complications
• Rejection is the main cause of morbidity and mortality.
Rejection negatively correlates with the survival of the graft.
• 50%–75% of recipients experience acute cellular rejection,
most commonly in the first 90 days, while chronic rejection
(CR) occurs in 15% of patients (18)
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37. Graft rejection
• The diagnosis of AR is possible by clinical, endoscopic, and
pathological evaluation.
• The gold standard for the diagnosis of AR is pathologic
evaluation by biopsy.
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38. • Endoscopic observation and biopsies are performed through
ileostomy. The endoscopic observation should be performed
two to three times in a week in the first three months. Then,
it is performed once a month according to the course of
transplantation.
• Mucosal erythema, edema, shortened and flattened villi,
friability, and ulcerations are endoscopic findings associated
with AR.
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40. Immune Monitoring
• Acute rejection, chronic rejection, lymphoproliferative
diseases due to over immune suppression.
• increase in use of measurements of citrulline level in the
blood, cytofluorographic analysis of peripheral immune
cell population, cytokine profiles,
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41. • Myeloid dentritic cells (MDC) are potent antigen-presenting
cells and serve as markers for the recipients who are prone to
AR (Biomarkers)
• Laser Doppler monitoring, implantable Doppler - appears to
be the ideal method for monitoring grafts, an early warning
of venous congestion may be detected.
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43. • Stool Calprotectin testing - >160 mg/kg
• During episodes of intestinal dysfunction, calprotectin levels
significantly increase.
• Recent role of Donor Specific Antibodies(DSAs) - can
develop de novo or are present in recipient - 30% risk of graft
loss <2yrs
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44. Immunosuppressive Therapy-
• Anti-lymphocyte antibodies and monoclonal (alemtuzumab,
basiliximab, and daclizumab) or polyclonal (thymoglobulin)
induction therapy (7, 27).
• Tacrolimus - maintenance of immune suppression; in the first
month, levels are kept as 12–15 ng/mL and lowered to 8–12
ng/mL after the first stage
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45. • BMMSCs, which show an immunosuppressive activity in
transplantation, are detected for stopping the immunological
refractory cells that attack the transplanted organs.
• They can also urge and carry on the process of
epithelialization of the small intestinal epithelium, enhanced
by cell proliferation and/or inhibition of epithelial cell
apoptosis.
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46. Future goal
• In an animal model, small sections of small bowel,
produced by implanting intestine stem cells on
collagen structures, demonstrated improved growth
after placing the graft in continuity with remnant
bowel surgically
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47. References
• Kaufman SS, Pehlivanova M, Fennelly EM, Rekhtman YM, Gondolesi GE, Little CA, et al. Predicting liver
failure in parenteral nutrition-dependent short bowel syndrome of infancy. J Pediatr. 2010;156:580–585.
• Kato T, Selvaggi, Gaynor JJ, Takahashi H, Nishida S, Moon J, et al. Inclusion of donor colon and ileocecal valve
in intestinal transplantation. Transplantation. 2008;86:293–297
• Sheth J, Sharif K, Lloyd C, Gupte G, Kelly D, de Ville de Goyet J, et al. Staged abdominal closure after small
bowel or multivisceral transplantation. Pediatr Transplant. 2012;16:36–40.
• Gangemi A, Tzvetanov IG, Beatty E, Oberholzer J, Testa G, Sankary HN, et al. Lessons learned in pediatric
small bowel and liver transplantation from living-related donors. Transplantation. 2009;87:1027–1030.
• 17. Oltean M, Churchill TA. Organ-specific solutions and strategies for the intestinal preservation. Int Rev
Immunol. 2014;33:234–244.
• 18. Mathew JM, Tryphonopoulos P, DeFaria W, Ruiz P, Miller J, Barrett TA, et al. Role of innate and acquired
immune mechanisms in clinical intestinal transplant rejection. Transplantation. 2015;99:1273–1281.
• Chen-Shuan Chung, Chien-Chen Tsai, Kuan-Chih Chen, Cheng-Kuan Lin, Tzong-Hsi Lee, Huang-Wen Tsai, Yun
Chen, Surveillance of Rejection After Intestinal Transplantation Using an Image Enhanced Endoscopy
“VENCH” Scoring System,Transplantation Proceedings,Volume 53, Issue 1,2021,Pages 364-370,ISSN 0041-
1345,https://doi.org/10.1016/j.transproceed.2020.10.002.
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