Treatment of intestinal failure: intestinal transplantation

Enhancement of Colonic Absorptive Function after the Massive Resection of the Small Intestine Based on the Creation of an Artificial Colonic Valve

The colon can have an absorptive function similar to that of the small intestine after the massive resection of the small bowel. To improve colonic absorptive function, we created a valve in the colon (artificial colonic valve, ACV). ACVs were created in 20 rats that had 80 percent of their small intestine resected, with an observation time of 30 weeks. The ACV rats were compared with those in the non-operated control group, the short bowel syndrome (SBS) group and the colon interposition (CI) group. The ACV rats were much heavier than those in the control group, SBS group and CI group. In terms of histology and the levels of α-amylase and the Na⁺-dependent bile salt transporter, the absorptive function of the colons before the valves resembled that of the small intestine. The colonic absorptive function was more obvious in ACV rats than in CI rats. An ACV can enhance colonic absorptive function after the massive resection of the small intestine. The colonic absorptive function of ACV rats was better than that of the rats in the CI group.

Gut microbiota and its implications in small bowel transplantation

The gut microbiota is mainly composed of a diverse population of commensal bacterial species and plays a pivotal role in the maintenance of intestinal homeostasis, immune modulation and metabolism. The influence of the gut microbiota on solid organ transplantation has recently been recognized. In fact, several studies indicated that acute and chronic allograft rejection in small bowel transplantation (SBT) is closely associated with the alterations in microbial patterns in the gut. In this review, we focused on the recent findings regarding alterations in the microbiota following SBTand the potential roles of these alterations in the development of acute and chronic allograft rejection. We also reviewed important advances with respect to the interplays between the microbiota and host immune systems in SBT. Furthermore, we explored the potential of the gut microbiota as a microbial marker and/or therapeutic target for the predication and intervention of allograft rejection and chronic dysfunction. Given that current research on the gut microbiota has become increasingly sophisticated and comprehensive, large cohort studies employing metagenomic analysis and multivariate linkage should be designed for the characterization of host-microbe interaction and causality between microbiota alterations and clinical outcomes in SBT. The findings are expected to provide valuable insights into the role of gut microbiota in the development of allograft rejection and other transplant-related complications and introduce novel therapeutic targets and treatment approaches in clinical practice.

Reconstruction of Large Abdominal Wall Defects Using Neurotized Vascular Composite Allografts

BACKGROUND

Abdominal wall vascularized composite allotransplantation is the second most common form of vascularized composite allotransplantation. Sensory and functional recovery are expected in other forms but have never been demonstrated in abdominal wall vascularized composite allotransplantation. The authors hypothesize that coaptation of two thoracolumbar nerves will result in reinnervation of the alloflap and maintenance of the muscle component.

METHODS

Adult, male, 10-week-old Brown Norway and Lewis rats were used for experiments. The rat donor's common iliac vessels were anastomosed to the recipient's femoral vessels. Intercostal nerves T10/L1 were coapted. Four groups (n = 5 per group) were included for study: group 1, Lewis, intercostal nerves cut, not repaired; group 2, Lewis intercostal nerves cut, T10/L1 repaired; group 3, allogeneic Brown Norway-to-Lewis abdominal wall vascularized composite allotransplantation, T10/L1 repaired; and group 4, syngeneic Lewis-to-Lewis abdominal wall vascularized composite allotransplantation, T10/L1 repaired. Animals were killed on postoperative day 60. Nerve regeneration was assessed using muscle weight analysis, myofibril cross-sectional area, nerve histomorphometry, and neuromuscular junction percentage reinnervation.

RESULTS

Groups 2, 3, and 4 maintained a significantly greater percentage of postharvest weight compared with group 1 (p < 0.05). Group 1 had significantly decreased myofibril cross-sectional area compared with controls (p < 0.05). There was no significant difference in myofibril cross-sectional area in groups 2 through 4 compared with controls (p > 0.05). Group 1 had significantly decreased percentage reinnervation of the alloflap compared with controls (p < 0.05). There was no significant difference when comparing group 2 through 4 with internal, contralateral controls (p > 0.05).

CONCLUSION

In a murine model for abdominal wall vascularized composite allotransplantation, coaptation of T10/L1 will allow for reinnervation of the alloflap and maintenance of the muscle component.

Segmental reversal of the small bowel can end permanent parenteral nutrition dependency: an experience of 38 adults with short bowel syndrome

OBJECTIVE

This study aimed to assess the results of segmental reversal of the small bowel (SRSB) in patients with short bowel syndrome (SBS) who were "permanently" dependent on parenteral nutrition (PN) and to identify possible prognostic factors for weaning.

SUMMARY BACKGROUND DATA

SRSB is a nontransplant surgical option for patients with SBS who require long-term PN. Few studies have reported outcomes in humans.

METHODS

: All patients who were permanently dependent on PN and underwent a SRSB between 1985 and 2010 for SBS were included. The data were retrospectively retrieved.

RESULTS

Thirty-eight patients underwent SRSB. The median age was 55.5 years (range, 18-76). The median length of the small bowel remnant was 49 cm (20-140), including a reversed segment of 10 cm (6-15). The median follow-up was 57.7 months (1-304). At the 5-year follow-up, 17 patients had been weaned from PN (45%). In the remaining patients, PN dependency had decreased from 7 ± 1 to 4 ± 1 days per week. The survival rate was 84%. The prognostic factors for weaning were a short time between subtotal enterectomy and SRSB (P = 0.036), a longer than typical stay in the nutrition unit (P = 0.035), and an SRSB longer than 10 cm (P = 0.024).

CONCLUSIONS

SRSB has a role as a conservative alternative to small bowel transplantation in patients with SBS permanently dependent on PN. With a segmental reversal of 10 to 12 cm, almost half of the patients can be expected to be weaned from PN.

Intestinal transplantation: indications and prospects

Intestinal transplantation (IT) can involve small bowel transplantation alone, or be associated with liver or multivisceral transplantation. Although IT is the radical treatment for intestinal failure, home parenteral nutrition (PN) remains the treatment of choice for this disease. Indications for IT are still debated. A recent study showed that early referral for IT is recommended for patients with life-threatening combined liver and intestinal failure or for patients with invasive intra-abdominal desmoid tumors. In the same study, no survival benefit was shown for patients undergoing IT for ultra-short bowel or major complications related to the PN catheter; indications still need to be fully assessed. While short-term outcomes for IT have improved dramatically (one-year survival for small bowel-alone IT is now 80% versus 0-28% in the 1980s), long-term outcomes have not improved much since the introduction of Tacrolimus in the 1990s: five-year survival still does not exceed 60%. Some prospective developments could improve these results: the use of multivisceral grafts, the use of Sirolimus and Thymoglobulins in the immunosuppressive treatment, or the use of new biochemical markers for early diagnosis of graft rejection.

Risk factors and outcomes of Staphylococcus aureus infections after small bowel and multivisceral transplantation

BACKGROUND

No studies have evaluated the risk factors and outcomes of Staphylococcus aureus (SA) infections in small bowel (SBT) and multivisceral (including small bowel) transplantation (MVT).

METHODS

SBT and MVT recipients with SA infections (22 cases) were retrospectively identified and compared with matched non-SA-infected recipient controls (44). The characteristics were compared with Friedman and Cochran-Mantel-Haenszel tests. Conditional logistic regression analysis was performed to identify risk factors, and Kaplan-Meier curve and Cox proportional hazard model were performed for survival analysis.

RESULTS

The median age was 2.07 years (range, 0.76-54.04). Forty-three percent of the first SA infections were bloodstream infections, 30% lung infections, and 26% surgical site infections; 36% of these isolates were methicillin-resistant SA. Median time (days) to surgical site infections (41.0; range, 0-89) was significantly shorter than that to lung infections (266; range, 130-378) (P = 0.01). By univariate analysis, it was found that cases were more likely to have cytomegalovirus (CMV) sero-mismatch (odds ratio [OR] = 3.03 [95% confidence interval, 0.88-10.43]; P = 0.08), and controls were more likely to receive mycophenolate mofetil (MMF) treatment (0.09 [0.001-0.82]; P = 0.03). By multivariable analysis, patients with CMV sero-mismatch were found to have higher odds of developing SA infection (OR, 2.92; P = 0.085), whereas MMF had a protective effect (OR, 0.08; P = 0.031), adjusting for matched criteria. SA cases had shorter survival than controls (mean survival, 28.5 vs. 45.8 months [P = 0.04]) and were 2.18 times more likely to die (1.02-4.67, P = 0.04).

CONCLUSIONS

SA infections were associated with a significant shorter survival time and higher risk of death. The presence of CMV sero-mismatch and the absence of MMF treatment were found to be the risk factors for SA infections after SBT and MVT.

Intestinal lengthening in adult patients with short bowel syndrome

INTRODUCTION

Limited information regarding the usefulness of bowel lengthening in adult patients with short bowel syndrome is available.

METHODS

Retrospective review of a single center series of intestinal lengthening over 15-year period in patients ≥ 18 years old.

RESULTS

Twenty adult patients underwent Bianchi (n = 6) or serial transverse enteroplasty (STEP) (n = 15). Median age was 38 (18-66) years and 11 were female. Indications were (a) to increase the enteral caloric intake thereby reduce or wean parenteral nutrition (PN) (n = 14) or (b) for bacterial overgrowth (n = 6). Twelve patients required additional procedures to relieve the anatomical blockade. Median remnant bowel length prior to surgery, length gained and final bowel length was 60, 20, and 80 cm, respectively. Survival was 90% with mean follow-up of 4.1 years (range = 1-7.9 years). Two patients died during follow-up. Intestinal transplant salvage was required in one patient 4.8 years after STEP. Overall, of 17 patients, ten (59%) patients achieved enteral autonomy and were off PN. Of seven patients who are on PN, three patients showed significant improvement in enteral caloric intake. All except one showed significant improvement in symptoms of bacterial overgrowth.

CONCLUSIONS

Bowel lengthening is technically feasible and effectively leads to weaning from PN in more than half of the adult patients. Lengthening procedures may be an underutilized treatment for adults with short bowel syndrome.

Analysis of immune cells draining from the abdominal cavity as a novel tool to study intestinal transplant immunobiology

During intestinal transplant (ITx) operation, intestinal lymphatics are not reconstituted. Consequently, trafficking immune cells drain freely into the abdominal cavity. Our aim was to evaluate whether leucocytes migrating from a transplanted intestine could be recovered from the abdominal draining fluid collected by a peritoneal drainage system in the early post-ITx period, and to determine potential applications of the assessment of draining cellular populations. The cell composition of the abdominal draining fluid was analysed during the first 11 post-ITx days. Using flow cytometry, immune cells from blood and draining fluid samples obtained the same day showed an almost complete lymphopenia in peripheral blood, whereas CD3(+) CD4(+) CD8(-) , CD3(+) CD4(-) CD8(+) and human leucocyte antigen D-related (HLA-DR)(+) CD19(+) lymphocytes were the main populations in the draining fluid. Non-complicated recipients evolved from a mixed leucocyte pattern including granulocytes, monocytes and lymphocytes to an exclusively lymphocytic pattern along the first post-ITx week. At days 1-2 post-Itx, analysis by short tandem repeats fingerprinting of CD3(+) CD8(+) sorted T cells from draining fluid indicated that 50% of cells were from graft origin, whereas by day 11 post-ITx this proportion decreased to fewer than 1%. Our results show for the first time that the abdominal drainage fluid contains mainly immune cells trafficking from the implanted intestine, providing the opportunity to sample lymphocytes draining from the grafted organ along the post-ITx period. Therefore, this analysis may provide information useful for understanding ITx immunobiology and eventually could also be of interest for clinical management.

Hydrogen inhalation ameliorates oxidative stress in transplantation induced intestinal graft injury

Ischemia/reperfusion (I/R) injury during small intestinal transplantation (SITx) frequently causes complications including dysmotility, inflammation and organ failure. Recent evidence indicates hydrogen inhalation eliminates toxic hydroxyl radicals. Syngeneic, orthotopic SITx was performed in Lewis rats with 3 h of cold ischemic time. Both donor and recipient received perioperative air or 2% hydrogen inhalation. SITx caused a delay in gastrointestinal transit and decreased jejunal circular muscle contractile activity 24 h after surgery. Hydrogen treatment resulted in significantly improved gastrointestinal transit, as well as jejunal smooth muscle contractility in response to bethanechol. The transplant induced upregulation in the inflammatory mediators CCL2, IL-1 beta, IL-6 and TNF-alpha were mitigated by hydrogen. Hydrogen significantly diminished lipid peroxidation compared to elevated tissue malondialdehyde levels in air-treated grafts demonstrating an antioxidant effect. Histopathological mucosal erosion and increased gut permeability indicated a breakdown in posttransplant mucosal barrier function which was significantly attenuated by hydrogen treatment. In recipient lung, hydrogen treatment also resulted in a significant abatement in inflammatory mRNA induction and reduced neutrophil recruitment. Hydrogen inhalation significantly ameliorates intestinal transplant injury and prevents remote organ inflammation via its antioxidant effects. Administration of perioperative hydrogen gas may be a potent and clinically applicable therapeutic strategy for intestinal I/R injury.

Brain death induces inflammation in the donor intestine

BACKGROUND

Brain death donors are frequently used for transplantation. Previous studies showed that brain death (BD) negatively affects the immunological and inflammatory status of both liver and kidney. Because the intestine is increasingly used as a donor organ and no information on effects of BD on small intestine is available we performed this study.

METHODS

We studied the inflammatory and apoptotic changes in donor intestine after BD induction. Brain death was induced in rats by inflation of a balloon catheter. Three groups (n=6) were compared: 1-hr BD, 4-hr BD, and sham-operated controls.

RESULTS

An increased polymorphonuclear cell influx in ileum, as a measure of inflammation, was observed in 1- and 4-hr BD group compared with controls. Jejunum showed a significant increase at the 4-hr BD group compared with the control group. Intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, and interleukin-6 were upregulated after 1- and 4-hr BD. Caspase-3 positive cells were found in jejunum and ileum after 4-hr BD on the top of the villi. Serum interleukin-6 was severely elevated in the 1- and 4-hr brain dead rats.

CONCLUSION

These data show the early occurrence of intestinal inflammation and apoptosis after BD induction. These events may ultimately have a negative influence on the outcome of intestinal transplantation.