The concept of gut rehabilitation and the future of visceral transplantation

Exploring the immunological relevance of pre-transplant donor-specific antibody in intestinal transplantation, with special consideration to the liver

Despite recent advances that have improved outcomes following intestinal transplantation (ITx), achieving long-term patient survival and rejection-free survival is still challenging. Understanding the relevance of pre-transplant human leukocyte antigen (HLA) donor-specific antibody (DSA) in ITx and the immunomodulatory potential of the liver within the allograft is crucial to providing an accurate assessment of pre-transplant immunological risk, which could influence and improve post-transplant outcomes further. This was the primary objective of this retrospective study of 95 adult ITx transplants which took place at Cambridge University Hospitals (United Kingdom) between 2007 and 2019. Two novel programs were developed and validated to identify DSA (tested by Luminex single antigen beads) in this dataset. Data analysis utilised Kaplan-Meier survival methods, and statistical analysis was performed using log-rank tests and adjusted Cox models. Fifty-four (57%) ITx cases contained a liver, and 36 (38%) were sensitised to HLA. Pre-transplant DSA > 500 mean fluorescent intensity appeared to negatively affect post-ITx patient survival and rejection outcomes. Additionally, liver-inclusive allografts seemed to show particular resistance to HLA class I DSA. Our data hints towards consistency with other ITx studies where deleterious effects of DSA have been demonstrated, and where liver inclusion is protective from HLA class I DSA. This is in line with current national guidelines for immunological risk. Our publicly available research programs could support future large or multicentre studies where statistically relevant data might be gained.

Comparison of the effects of normothermic machine perfusion and cold storage preservation on porcine intestinal allograft regenerative potential and viability

Intestinal transplantation (IT) is the final treatment option for intestinal failure. Static cold storage (CS) is the standard preservation method used for intestinal allografts. However, CS and subsequent transplantation induce ischemia-reperfusion injury (IRI). Severe IRI impairs epithelial barrier function, including loss of intestinal stem cells (ISC), critical to epithelial regeneration. Normothermic machine perfusion (NMP) preservation of kidney and liver allografts minimizes CS-associated IRI; however, it has not been used clinically for IT. We hypothesized that intestine NMP would induce less epithelial injury and better protect the intestine's regenerative ability when compared with CS. Full-length porcine jejunum and ileum were procured, stored at 4 °C, or perfused at 34 °C for 6 hours (T6), and transplanted. Histology was assessed following procurement (T0), T6, and 1 hour after reperfusion. Real-time quantitative reverse transcription polymerase chain reaction, immunofluorescence, and crypt culture measured ISC viability and proliferative potential. A greater number of NMP-preserved intestine recipients survived posttransplant, which correlated with significantly decreased tissue injury following 1-hour reperfusion in NMP compared with CS samples. Additionally, ISC gene expression, spheroid area, and cellular proliferation were significantly increased in NMP-T6 compared with CS-T6 intestine. NMP appears to reduce IRI and improve graft regeneration with improved ISC viability and proliferation.

Nutrition care for the adult post-intestinal transplant patient

Intestinal transplantation has emerged as an accepted treatment choice for individuals experiencing irreversible intestinal failure. This treatment is particularly relevant for those who are not candidates or have poor response to autologous gut reconstruction or trophic hormone therapy, and who can no longer be sustained on parenteral nutrition. One of the main goals of transplant is to eliminate the need for parenteral support and its associated complications, while safely restoring complete nutrition autonomy. An intestinal transplant is a complex process that goes beyond merely replacing the intestines to provide nourishment and ceasing parenteral support. It requires an integrated management approach in the pretransplant and posttransplant setting, and high-quality nutrition treatment is one of the cornerstones leading to favorable outcomes and long-term management. Since the outset of intestinal transplant in the early 2000s, there is observed improvement of achieving nutrition autonomy sooner in the initial posttransplant phase; however, the development of nutrition complications in the chronic posttransplant period remains a long-term risk. This review delineates the decision-making process and clinical protocols used to nutritionally manage and monitor pre- and post-intestine transplant patients.

Growing experience of surgical gut rehabilitation: essential role in the management of gut failure in adult patients

PURPOSE OF REVIEW

With the inherent therapeutic limitations of gut transplantation, the concept of surgical gut rehabilitation was introduced to restore nutritional autonomy in pediatric patients. With favorable outcomes in these young patients, there has been increasing interest in the applicability of gut rehabilitative surgery to a growing population of adults with gut failure due to various etiologies. We aim to review the current status of surgical gut rehabilitation for adult gut failure patients in the era of multidisciplinary gut rehabilitation and transplantation.

RECENT FINDINGS

Indications for surgical gut rehabilitation have been gradually expanding, with gut failure after bariatric surgery recently added. Serial transverse enteroplasty (STEP) has been used with favorable outcomes in adult patients, including those with intrinsic intestinal disease. Autologous gut reconstruction (AGR) is the most frequently used surgical rehabilitative method; its outcome is further improved with conjunctive use of bowel lengthening and enterocyte growth factor as a part of comprehensive gut rehabilitation.

SUMMARY

Accumulated experiences have validated the efficacy of gut rehabilitation for survival, nutritional autonomy, and quality of life in adults with gut failure of various etiology. Further progress is expected with growing experience around the world.

Engineering Auxetic Cylinders and Intestine to Improve Longitudinal Intestinal Lengthening and Tailoring Procedure

Auxetic materials can be exploited for coupling different types of tissues. Herein, we designed a material where the microorganism metabolic activity yields the formation of buckled/collapsed bubbles within gelling silicone cylinders thus providing auxetic properties. The finite element model of such hollow auxetic cylinders demonstrated the tubular structure to promote worm-like peristalsis. In this scenario, the described hybrid auxetic structures may be applied to the longitudinal intestinal lengthening and tailoring procedure to promote enteral autonomy in short bowel syndrome. The presented material and analytical design synergistic approach offer a pioneering step for the clinical translation of hybrid auxetic materials.

Cost-effectiveness of Intestinal Transplantation Compared to Parenteral Nutrition in Adults

BACKGROUND

Intestinal transplantation (ITx) is the most expensive abdominal organ transplant. Detailed studies about exact costs and cost-effectiveness compared to home parenteral nutrition (HPN) therapy in chronic intestinal failure are lacking. The aim is to provide an in-depth analysis of ITx costs and evaluate cost-effectiveness compared to HPN.

METHODS

To calculate costs before and after ITx, costs were analyzed in 12 adult patients. To calculate the costs of patients with uncomplicated chronic intestinal failure, 28 adults, stable HPN patients were studied. Total costs including surgery, admissions, diagnostics, HPN therapy, medication, and ambulatory care were included. Median (range) costs are given.

RESULTS

Costs before ITx were €69 160 (€60 682-90 891) in year 2, and €104 146 (€83 854-186 412) in year 1. After ITx, costs were €172 133 (€122 483-351 407) in the 1st year, €40 619 (€3905-113 154) in the 2nd year, and dropped to €15 743 (€4408-138 906) in the 3rd year. In stable HPN patients, the costs were €83 402 (€35 364-169 146) in the 1st year, €70 945 (€31 955-117 913) in the 2nd year, and stabilized to €60 242 (€29 161-238 136) in the 3rd year.

CONCLUSIONS

ITx, although initially very expensive, is cost-effective compared to HPN in adults by year 4, and cost-saving by year 5.

Chronic intestinal failure and short bowel syndrome in Crohn’s disease

Chronic intestinal failure (CIF) is a rare but feared complication of Crohn’s disease. Depending on the remaining length of the small intestine, the affected intestinal segment, and the residual bowel function, CIF can result in a wide spectrum of symptoms, from single micronutrient malabsorption to complete intestinal failure. Management of CIF has improved significantly in recent years. Advances in home-based parenteral nutrition, in particular, have translated into increased survival and improved quality of life. Nevertheless, 60% of patients are permanently reliant on parenteral nutrition. Encouraging results with new drugs such as teduglutide have added a new dimension to CIF therapy. The outcomes of patients with CIF could be greatly improved by more effective prevention, understanding, and treatment. In complex cases, the care of patients with CIF requires a multidisciplinary approach involving not only physicians but also dietitians and nurses to provide optimal intestinal rehabilitation, nutritional support, and an improved quality of life. Here, we summarize current literature on CIF and short bowel syndrome, encompassing epidemiology, pathophysiology, and advances in surgical and medical management, and elucidate advances in the understanding and therapy of CIF-related complications such as catheter-related bloodstream infections and intestinal failure-associated liver disease.

Decline in renal function following intestinal transplant: is the die cast at 3 months?

INTRODUCTION

This study reports the incidence of chronic kidney disease (CKD) after intestinal transplant (IT) at a single, adult center in the United Kingdom.

METHODS

A retrospective review of IT was undertaken. Methods of renal function assessment pre-transplant were compared. Post-transplant renal function and renal sparing strategies were analyzed.

RESULTS

There was a 30% variation (p < .001) in estimated glomerular filtration rate (eGFR) and normalized GFR at assessment. In the first 3 months post-transplant, there was a 40% decline in eGFR which was irreversible. Liver inclusion was not protective with similar eGFR at 3 months (60 ml/min/1.73 m² ) compared with IT (55 ml/min/1.73 m² ). The rate of decline in the first 2 months was less in multivisceral transplant (MVT; 21%) than IT (52%) suggesting surgical magnitude did not contribute. Thirty percentage of recipients had acute cellular rejection post-transplant; 58% of these were in the first 3 months with a higher proportion in MVT (64%) than IT (27%). Tacrolimus exposure did not correlate with decline in renal function over the first 3 months post-transplant.

CONCLUSION

We demonstrated a 40% decline in renal function within 3 months post-IT which was irreversible despite renal sparing strategies. Early intervention should be considered in patients with an acute decline in this post-transplant period.

Twenty Years of Gut Transplantation for Chronic Intestinal Pseudo-obstruction: Technical Innovation, Long-term Outcome, Quality of Life, and Disease Recurrence

OBJECTIVE

To define long-term outcome, predictors of survival, and risk of disease recurrence after gut transplantation (GT) in patients with chronic intestinal pseudo-obstruction (CIPO).

BACKGROUND

GT has been increasingly used to rescue patients with CIPO with end-stage disease and home parenteral nutrition (HPN)-associated complications. However, long-term outcome including quality of life and risk of disease recurrence has yet to be fully defined.

METHODS

Fifty-five patients with CIPO, 23 (42%) children and 32 (58%) adults, underwent GT and were prospectively studied. All patients suffered gut failure, received HPN, and experienced life-threatening complications. The 55 patients received 62 allografts; 43 (67%) liver-free and 19 (33%) liver-contained with 7 (13%) retransplants. Hindgut reconstruction was adopted in 1993 and preservation of native spleen was introduced in 1999. Immunosuppression was tacrolimus-based with antilymphocyte recipient pretreatment in 41 (75%).

RESULTS

Patient survival was 89% at 1 year and 69% at 5 years with respective graft survival of 87% and 56%. Retransplantation was successful in 86%. Adults experienced better patient (P = 0.23) and graft (P = 0.08) survival with lower incidence of post-transplant lymphoproliferative disorder (P = 0.09) and graft versus host disease (P = 0.002). Antilymphocyte pretreatment improved overall patient (P = 0.005) and graft (P = 0.069) survival. The initially restored nutritional autonomy was sustainable in 23 (70%) of 33 long-term survivors with improved quality of life. The remaining 10 recipients required reinstitution of HPN due to allograft enterectomy (n = 3) or gut dysfunction (n = 7). Disease recurrence was highly suspected in 4 (7%) recipients.

CONCLUSIONS

GT is life-saving for patients with end-stage CIPO and HPN-associated complications. Long-term survival is achievable with better quality of life and low risk of disease recurrence.

Disease recurrence after gut transplantation

PURPOSE OF REVIEW

Despite three decades of clinical experience, this article is the first to comprehensively address disease recurrence after gut transplantation. Pertinent scientific literature is reviewed and management strategies are discussed with new insights into advances in gut pathobiology and human genetics.

RECENT FINDINGS

With growing experience and new perspectives in the field of gut transplantation, the topic of disease recurrence continues to evolve. The clinicopathologic spectrum and diagnostic criteria are better defined in milieu of the nature of the primary disease. In addition to neoplastic disorders, disease recurrence is suspected in patients with pretransplant Crohn's disease, gut dysmotility, hypercoagulability and metabolic syndrome. There has also been an increased awareness of the potential de-novo development of various disorders in the transplanted organs. For conventionally unresectable gastrointestinal and abdominal malignancies, ex-vivo excision and autotransplantation are advocated, particularly for the nonallotransplant candidates.

SUMMARY

Similar to other solid organ and cell transplantations, disease recurrence has been suspected following gut transplantation. Despite current lack of conclusive diagnostic criteria, recurrence of certain mucosal and neuromuscular disorders has been recently described in a large single-centre series with an overall incidence of 7%. Disease recurrence was also observed in recipients with pretransplant hypercoagulability and morbid obesity with respective incidences of 4 and 24%. As expected, tumour recurrence is largely determined by type, extent and biologic behaviour of the primary neoplasm. With the exception of high-grade aggressive malignancy, disease recurrence is still of academic interest with no significant impact on overall short and long-term outcome.

Paneth Cell Alterations During Ischemia-reperfusion, Follow-up, and Graft Rejection After Intestinal Transplantation

BACKGROUND

Ischemia-reperfusion injury is inevitable during intestinal transplantation (ITx) and executes a key role in the evolution towards rejection. Paneth cells (PCs) are crucial for epithelial immune defense and highly vulnerable to ischemia-reperfusion injury. We investigated the effect of ITx on PC after reperfusion (T0), during follow-up, and rejection. Moreover, we investigated whether PC loss was associated with impaired graft homeostasis.

METHODS

Endoscopic biopsies, collected according to center protocol and at rejection episodes, were retrospectively included (n = 28 ITx, n = 119 biopsies) Biopsies were immunohistochemically co-stained for PC (lysozyme) and apoptosis, and PC/crypt and lysozyme intensity were scored.

RESULTS

We observed a decrease in PC/crypt and lysozyme intensity in the first week after ITx (W1) compared with T0. There was a tendency towards a larger decline in PC/crypt (P = 0.08) and lysozyme intensity (P = 0.08) in W1 in patients who later developed rejection compared with patients without rejection. Follow-up biopsies showed that the PC number recovered, whereas lysozyme intensity remained reduced. This persisting innate immune defect may contribute to the well-known vulnerability of the intestine to infection. There was no clear evidence that PCs were affected throughout rejection.

CONCLUSIONS

This study revealed a transient fall in PC numbers in the early post-ITx period but a permanent reduction in lysozyme intensity following ITx. Further research is needed to determine the potential clinical impact of PC impairment after ITx.

Management of Five Hundred Patients With Gut Failure at a Single Center: Surgical Innovation Versus Transplantation With a Novel Predictive Model

OBJECTIVE(S)

To define the evolving role of integrative surgical management including transplantation for patients gut failure (GF).

METHODS

A total of 500 patients with total parenteral nutrition-dependent catastrophic and chronic GF were referred for surgical intervention particularly transplantation and comprised the study population. With a mean age of 45 ± 17 years, 477 (95%) were adults and 23 (5%) were children. Management strategy was guided by clinical status, splanchnic organ functions, anatomy of residual gut, and cause of GF. Surgery was performed in 462 (92%) patients and 38 (8%) continued medical treatment. Definitive autologous gut reconstruction (AGR) was achievable in 378 (82%), primary transplant in 42 (9%), and AGR followed by transplant in 42 (9%). The 84 transplant recipients received 94 allografts; 67 (71%) liver-free and 27 (29%) liver-contained. The 420 AGR patients received a total of 790 reconstructive and remodeling procedures including primary reconstruction, interposition alimentary-conduits, intestinal/colonic lengthening, and reductive/decompressive surgery. Glucagon-like peptide-2 was used in 17 patients.

RESULTS

Overall patient survival was 86% at 1-year and 68% at 5-years with restored nutritional autonomy (RNA) in 63% and 78%, respectively. Surgery achieved a 5-year survival of 70% with 82% RNA. AGR achieved better long-term survival and transplantation better (P = 0.03) re-established nutritional autonomy. Both AGR and transplant were cost effective and quality of life better improved after AGR. A model to predict RNA after AGR was developed computing anatomy of reconstructed gut, total parenteral nutrition requirements, cause of GF, and serum bilirubin.

CONCLUSIONS

Surgical integration is an effective management strategy for GF. Further progress is foreseen with the herein-described novel techniques and established RNA predictive model.

Long-term survival in visceral transplant recipients in the new era: A single-center experience

There is a paucity of data on long-term outcomes following visceral transplantation in the contemporary era. This is a single-center retrospective analysis of all visceral allograft recipients who underwent transplant between November 2003 and December 2013 with at least 3-year follow-up data. Clinical data from a prospectively maintained database were used to assess outcomes including patient and graft survival. Of 174 recipients, 90 were adults and 84 were pediatric patients. Types of visceral transplants were isolated intestinal transplant (56.3%), combined liver-intestinal transplant (25.3%), multivisceral transplant (16.1%), and modified multivisceral transplant (2.3%). Three-, 5-, and 10-year overall patient survival was 69.5%, 66%, and 63%, respectively, while 3-, 5-, and 10-year overall graft survival was 67%, 62%, and 61%, respectively. In multivariable analysis, significant predictors of survival included pediatric recipient (P = .001), donor/recipient weight ratio <0.9 (P = .008), no episodes of severe acute rejection (P = .021), cold ischemia time <8 hours (P = .014), and shorter hospital stay (P = .0001). In conclusion, visceral transplantation remains a good option for treatment of end-stage intestinal failure with parenteral nutritional complications. Proper graft selection, shorter cold ischemia time, and improvement of immunosuppression regimens could significantly improve the long-term survival.

Short Bowel Syndrome as the Leading Cause of Intestinal Failure in Early Life: Some Insights into the Management

Intestinal failure (IF) is the critical reduction of the gut mass or its function below the minimum needed to absorb nutrients and fluids required for adequate growth in children. Severe IF requires parenteral nutrition (PN). Pediatric IF is most commonly due to congenital or neonatal intestinal diseases or malformations divided into 3 groups: 1) reduced intestinal length and consequently reduced absorptive surface, such as in short bowel syndrome (SBS) or extensive aganglionosis; 2) abnormal development of the intestinal mucosa such as congenital diseases of enterocyte development; 3) extensive motility dysfunction such as chronic intestinal pseudo-obstruction syndromes. The leading cause of IF in childhood is the SBS. In clinical practice the degree of IF may be indirectly measured by the level of PN required for normal or catch up growth. Other indicators such as serum citrulline have not proven to be highly reliable prognostic factors in children. The last decades have allowed the development of highly sophisticated nutrient solutions consisting of optimal combinations of macronutrients and micronutrients as well as guidelines, promoting PN as a safe and efficient feeding technique. However, IF that requires long-term PN may be associated with various complications including infections, growth failure, metabolic disorders, and bone disease. IF Associated Liver Disease may be a limiting factor. However, changes in the global management of IF pediatric patients, especially since the setup of intestinal rehabilitation centres did change the prognosis thus limiting "nutritional failure" which is considered as a major indication for intestinal transplantation (ITx) or combined liver-ITx.

Non-transplant Surgical Management of Short Bowel Syndrome in Children: An Overview

Management of severe Short Bowel Syndrome (SBS) is still one of the largest challenges of the medicine. Vast majority of the short bowel patients are children, the conditions that lead to this possible outcome most often are necrotizing enterocolitis (NEC), small intestinal volvulus as a result of intestinal malrotation, gastroschisis and the "apple peel" syndrome. Therefore, paediatricians and paediatric surgeons face this challenge most often. The nontransplant treatment appears to be effective using surgical procedure to increase absorptive surface and to reduce the transit time, but in some cases these procedures are enough to weaning of TPN. The aim of this review was to summarize the modern non-stransplant surgical management of short bowel syndrome.

Composite and Multivisceral Transplantation: Nomenclature, Surgical Techniques, Current Practice, and Long-term Outcome

The successful development of multivisceral and composite visceral transplantation is among the milestones in the recent history of human organ transplantation. All types of gastrointestinal transplantation have evolved to be the standard of care for patients with gut failure and complex abdominal pathologic conditions. The outcome has markedly improved over the last 3 decades owing to technical innovation, novel immunosuppression, and better postoperative care. Recent data documented significant improvement in the long-term therapeutic indices of all types of visceral transplantation close to that achieved with thoracic and solid abdominal organs.

Myeloid-derived suppressor cells increase and inhibit donor-reactive T cell responses to graft intestinal epithelium in intestinal transplant patients

Recent advances in immunosuppressive regimens have decreased acute cellular rejection (ACR) rates and improved intestinal and multivisceral transplant (ITx) recipient survival. We investigated the role of myeloid-derived suppressor cells (MDSCs) in ITx. We identified MDSCs as CD33⁺ CD11b⁺ lineage(CD3/CD56/CD19)^- HLA-DR^-/low cells with 3 subsets, CD14^- CD15^- (e-MDSCs), CD14⁺ CD15^- (M-MDSCs), and CD14^- CD15⁺ (PMN-MDSCs), in peripheral blood mononuclear cells (PBMCs) and mononuclear cells in the grafted intestinal mucosa. Total MDSC numbers increased in PBMCs after ITx; among MDSC subsets, M-MDSC numbers were maintained at a high level after 2 months post ITx. The MDSC numbers decreased in ITx recipients with ACR. MDSC numbers were positively correlated with serum interleukin (IL)-6 levels and the glucocorticoid administration index. IL-6 and methylprednisolone enhanced the differentiation of bone marrow cells to MDSCs in vitro. M-MDSCs and e-MDSCs expressed CCR1, -2, and -3; e-MDSCs and PMN-MDSCs expressed CXCR2; and intestinal grafts expressed the corresponding chemokine ligands after ITx. Of note, the percentage of MDSCs among intestinal mucosal CD45⁺ cells increased after ITx. A novel in vitro assay demonstrated that MDSCs suppressed donor-reactive T cell-mediated destruction of donor intestinal epithelial organoids. Taken together, our results suggest that MDSCs accumulate in the recipient PBMCs and the grafted intestinal mucosa in ITx, and may regulate ACR.

Total pancreaticoduodenectomy with autologous islet transplantation 14 years after liver-contained composite visceral transplantation

Chronic pancreatitis (CP) is a severely disabling disorder with potential detrimental effects on quality of life, gut function, and glucose homeostasis. Disease progression often results in irreversible morphological and functional abnormalities with development of chronic pain, mechanical obstruction, and pancreatic insufficiency. Along with comprehensive medical management, the concept of total pancreatectomy and islet autotransplantation (TP-AIT) was introduced 40 years ago for patients with intractable pain and preserved beta-cell function. With anticipated technical difficulties, total excision of the inflamed-disfigured gland is expected to alleviate the incapacitating visceral pain and correct other associated abdominal pathology. With retrieval of sufficient islet-cell mass, the autologous transplant procedure has the potential to maintain an euglycemic state without exogenous insulin requirement. The reported herein case of CP-induced recalcitrant pain and foregut obstruction is exceptional because of the technical challenges in performing native pancreaticoduodenectomy in close proximity to the composite visceral allograft with complex vascular and gut reconstructions. Equally novel is transplanting the auto-islets in the liver-contained visceral allograft. Despite intravenous nutrition shortly after birth, liver transplantation at age 13, retransplantation with liver-contained visceral allograft at age 17 and TP-AIT at age 31, the 38-year-old recipient is currently pain free with full nutritional autonomy and normal glucose homeostasis.

Composite and Multivisceral Transplantation: Nomenclature, Surgical Techniques, Current Practice, and Long-term Outcome

The successful development of multivisceral and composite visceral transplantation is among the milestones in the recent history of human organ transplantation. All types of gastrointestinal transplantation have evolved to be the standard of care for patients with gut failure and complex abdominal pathologic conditions. The outcome has markedly improved over the last 3 decades owing to technical innovation, novel immunosuppression, and better postoperative care. Recent data documented significant improvement in the long-term therapeutic indices of all types of visceral transplantation close to that achieved with thoracic and solid abdominal organs.

Small-for-size Syndrome Does Not Occur in Intestinal Transplantation Without Liver Containing Grafts

BACKGROUND

The ideal donor in intestinal transplantation (ITX) is generally considered to be 50% to 70% of recipient body weight. This may be due to concerns for "small for size" syndrome as seen in liver transplantation. We report our experience using smaller donors (donor-recipient weight ratio [DRWR], < 50%) in ITX recipients.

METHODS

We studied a group of ITX recipients with DRWR of 50% or less to unmatched controls who received intestinal allografts with DRWR greater than 50%. We examined patient and graft survival and enteral autonomy from parenteral nutrition as surrogate markers for safety of using smaller donors and ease of abdominal wall closure between groups to determine the value.

RESULTS

There was no difference in overall patient and graft survival, time to enteral autonomy from parenteral nutrition, and weight gain after ITX over time between groups. The need for complicated abdominal closure techniques was significantly more frequent in the control group than in the study group (34.6% vs 6.9%, P = 0.01). Secondary abdominal closure occurred more frequently in the control group (15.4% vs 0%, P = 0.014). Wound revisions also occurred more frequently in the control group (15.4% vs 0%, P = 0.028).

CONCLUSIONS

Our data suggest that ITX using smaller donors (DRWR ≤ 50%) seems to be an acceptable practice without adverse impact on surgical complications, nutritional autonomy, and patient and graft survival. Abdominal wall closure seems easier in recipients of smaller donors and "small for size" syndrome as described in liver transplantation does not occur with intestinal allografts.

Pancreatic and Intestinal Function Post Roux-en-Y Gastric Bypass Surgery for Obesity

OBJECTIVES

Despite the fact that the most effective treatment for morbid obesity today is gastric bypass surgery, some patients develop life-threatening nutritional complications associated with their weight loss.

METHODS

Here we examine the influence of the altered anatomy and digestive physiology on pancreatic secretion and fat absorption. Thirteen post Roux-en-Y gastric bypass (RYGB) patients who had lost >100 lbs in the first year following surgery and who gave variable histories of gastrointestinal (GI) dysfunction, were selected for study. Food-stimulated pancreatic enzyme secretion and GI hormone responses were measured during 2 h perfusions of the Roux limb with a standard polymeric liquid formula diet and polyethylene glycol marker, with collections of secretions from the common channel distal to the anastomosis and blood testing. Fat absorption was then measured during a 72 h balance study when a normal diet was given containing ~100 g fat/d.

RESULTS

Result showed that all patients had some fat malabsorption, but eight had coefficients of fat absorption <80%, indicative of steatorrhea. This was associated with significantly lower feed-stimulated secretion rates of trypsin, amylase, and lipase, and higher plasma peptide-YY concentrations compared with healthy controls. Five steatorrhea patients were subsequently treated with low quantities of pancreatic enzyme supplements for 3 months, and then retested. The supplements were well tolerated, and fat absorption improved in four of five patients accompanied by an increase in lipase secretion, but body weight increased in only three. Postprandial breath hydrogen concentrations were elevated with some improvement following enzyme supplementation suggesting persistent bacterial overgrowth and decreased colonic fermentation.

CONCLUSIONS

Our investigations revealed a wide spectrum of gastrointestinal abnormalities, including fat malabsorption, impaired food stimulated pancreatic secretion, ileal brake stimulation, and bacterial overgrowth, in patients following RYGB which could be attributed to the breakdown of the normally highly orchestrated digestive anatomy and physiology.

William Hunter Harridge lecture: The changing face of short-gut syndrome management

The evolution of managing short gut syndrome optimizes management and decision making of intestinal failure by way of a multidisciplinary team utilizing the latest advances in therapeutic options. Only the minority of patients referred for small bowel transplantation will actually need a transplant. Many of these patients can be rehabilitated without the need for transplant, by way of early referral, and thus the likelihood of medical therapy increases. On the other hand, in those patients with little likelihood of success with medical therapy, early referral decreases the morbidity and mortality associated with long-term total parenteral nutrition and associated complications and will improve their overall survival outcomes.

Adult Intestinal and Multivisceral Transplantation: Experience From a Single Center in the United Kingdom

Cambridge is one of two designated adult intestinal transplant centers in the United Kingdom and has performed 60 transplants on 54 patients since 2007; 52% of these were undertaken in the last 3 years. This increasing trend is in contrast with that reported worldwide; 27% were small bowel grafts (SBT), 15% modified multivisceral (MMVT), and 58% multivisceral (MVT). Median recipient age was 47 years; the female-to-male ratio was 27/33. Primary diseases included visceral arterial thromboses (17%), Crohn's disease (17%), motility disorders (12%), visceral venous thromboses (12%), familial adenomatous polyposis (FAP)/desmoids (8%), alcoholic cirrhosis (3%), nonalcoholic fatty liver disease (3%), ulcerative colitis (2%), and other (15%). Indications for transplant included intestinal failure-associated liver disease (IFALD) (27%), loss of central venous access (17%), FAP/desmoid disease (5%), extensive portomesenteric venous thrombosis (PMVT) (20%), widespread mesenteric arterial ischemia (WMAI) (13%), re-transplant (8%), and other (10%). Overall 1-year/5-year patient survival rates were 77%/62%. One-year/5-year patient survival rates were 92%/83%, 85%/65%, and 71%/33% for SBT, MMVT, and MVT. One-year/5-year survival rates for patients with IFALD, PMVT, and other indications who underwent MVT were 80%/20%, 65%/55%, and 55%/35%. The greatest proportion of patient deaths occurred during the first year after transplant (50% in year 1, 23% in year 2, 9% in year 3, 5% in year 4, and 14% in year 5), particularly in the MVT group. Referrals to our United Kingdom center are increasing, and the indications for transplant are becoming more diverse. Our patient survival rates remain comparable with figures reported worldwide.

Intestinal Failure and Transplant: The Australian Experience (2009 to 2014)

BACKGROUND

A joint adult and pediatric intestinal transplant (ITx) program for Australia was developed in 2009 to provide life-saving ITx to patients with irreversible intestinal failure (IF). We aimed to analyze the outcomes of patients treated by our service over the past 5 years.

METHODS

A retrospective medical record review was conducted on all IF patients referred to our service. Patient demographics, underlying disease, nutrition support, TPN complications, and current transplant program status were evaluated.

RESULTS

Fifty-seven patients (35 adults, 40.4 ± 12.4 years; 22 children, 6.3 ± 4.3 years) throughout Australia and New Zealand have been referred. Leading causes of IF were short bowel syndrome followed by pseudo-obstruction. Forty patients (70%) exhibited at least 1 life-threatening complication of PN at referral: liver failure, impending loss of venous access, and/or recurrent line sepsis. Three patients have undergone ITx with 100% survival (median follow-up, 1161 days). Four patients (8%) are listed for transplant, 6 patients (12%) are awaiting transplant assessment, and 4 patients (8%) have died (2 while awaiting transplantation, 2 during assessment period). Causes of death included sepsis and intracranial bleed. Two-thirds of all referred patients (n = 40) were deferred or rejected from wait-listing.

CONCLUSIONS

After 5 years of establishing the first dedicated ITx program in Australia and New Zealand, early results indicate that ITx is an available and life-saving option for IF patients in these countries. Current barriers to ITx in Australia include a shortage of appropriate donors and a high rate of donor-specific antibodies among potential recipients. Growing awareness of the service and early referral to assist appropriate patient selection will aid in the program's success.

Choice of Allograft in Patients Requiring Intestinal Transplantation: A Critical Review

Intestinal transplantation (ITx) is indicated in patients with irreversible intestinal failure (IF) and life-threatening complications related to total parenteral nutrition (TPN). ITx can be classified into three main types. Isolated intestinal transplantation (IITx), that is, transplantation of the jejunoileum, is indicated in patients with preserved liver function. Combined liver-intestine transplantation (L-ITx), that is, transplantation of the liver and the jejunoileum, is indicated in patients with liver failure related to TPN. Thus, patients with cirrhosis or advanced fibrosis should receive a combined allograft, while patients with lower grades of liver fibrosis can usually safely undergo ITx. Reflecting their degree of sickness, the waitlist mortality rate and the early posttransplant outcomes of patients receiving L-ITx are worse than IITx. However, L-ITx is associated with better long-term graft and patient survival. Multivisceral transplantation (MVTx), that is, transplantation of the organs dependent on the celiac axis and superior mesenteric artery, can be classified into full MVTx if it includes the liver and modified MVTx if it does not. The most common indications for MVTx are extensive portomesenteric thrombosis and diffuse gastrointestinal pathology such as motility disorders and polyposis syndrome. Every patient with IF should undergo a multidisciplinary evaluation by an experienced ITx team.

The Leuven Immunomodulatory Protocol Promotes T-Regulatory Cells and Substantially Prolongs Survival After First Intestinal Transplantation

Intestinal transplantation (ITx) remains challenged by frequent/severe rejections and immunosuppression-related complications (infections/malignancies/drug toxicity). We developed the Leuven Immunomodulatory Protocol (LIP) in the lab and translated it to the clinics. LIP consists of experimentally proven maneuvers, destined to promote T-regulatory (Tregs)-dependent graft-protective mechanisms: donor-specific blood transfusion (DSBT); avoiding high-dose steroids/calcineurin-inhibitors; and minimizing reperfusion injury and endotoxin translocation. LIP was tested in 13 consecutive ITx from deceased donors (2000-2014) (observational cohort study). Recipient age was 37 years (2.8-57 years). Five-year graft/patient survival was 92%. One patient died at 9 months due to aspergillosis, another at 12 years due to nonsteroidal anti-inflammatory drug-induced enteropathy. Early acute rejection (AR) developed in two (15%); late AR in three (23%); all were reversible. No chronic rejection (CR) occurred. No malignancies developed and estimated glomerular filtration rate remained stable post-Tx. At last follow-up (3.5 years [0.5-12.5 years]), no donor-specific antibodies were detected and 11 survivors were total parenteral nutrition free with a Karnofsky score >90% in 8 recipients (follow-up >1 years). A high frequency of circulating CD4⁺ CD45RA^- Foxp3^hi memory Tregs was found (1.8% [1.39-2.21]), comparable to tolerant kidney transplant (KTx) recipients and superior to stable immunosuppression (IS)-KTx, KTx with CR, and healthy volunteers. In this ITx cohort we show that DSBT in a low-inflammatory/pro-regulatory environment activates Tregs at levels similar to tolerant-KTx, without causing sensitization. LIP limits rejection under reduced IS and thereby prolongs long-term survival to an extent not previously attained after ITx.

Pharmacological strategies to enhance adaptation in intestinal failure

PURPOSE OF REVIEW

Intestinal failure because of more or less extensive resection of parts of the small and large intestine (short bowel syndrome) results from the reduction of absorptive surface of the remaining intestine and frequently results in dependence on parenteral nutrition. Parenteral nutrition, although lifesaving, is associated with short and long-term complications as well as with reduced quality of life and overall survival.

RECENT FINDINGS

Pharmacological enhancement of the physiological intestinal adaptive response by subcutaneous application of the glucagon-like peptide 2 analogue teduglutide results in an improved, hyperadaptive response. This is reflected by decreased parenteral calorie and fluid requirements, decreased parenteral nutrition infusion days per week including complete weaning off parenteral nutrition with complete oral autonomy, improved quality of life, and metabolic and nutritional stability.

SUMMARY

The advent of teduglutide as an authority-approved specific medication for intestinal failure in parenteral nutrition-dependent short bowel syndrome offers an effective and beneficial treatment for these patients. As a result, patients are more stable whether for medical or further surgical management including intestinal transplantation. Long-term efficacy and safety still have to be proven.

Generation of an artificial intestine for the management of short bowel syndrome

PURPOSE OF REVIEW

This article discusses the current state of the art in artificial intestine generation in the treatment of short bowel syndrome.

RECENT FINDINGS

Short bowel syndrome defines the condition in which patients lack sufficient intestinal length to allow for adequate absorption of nutrition and fluids, and thus need parenteral support. Advances toward the development of an artificial intestine have improved dramatically since the first attempts in the 1980s, and the last decade has seen significant advances in understanding the intestinal stem cell niche, the growth of complex primary intestinal stem cells in culture, and fabrication of the biomaterials that can support the growth and differentiation of these stem cells. There has also been recent progress in understanding the role of the microbiota and the immune cells on the growth of intestinal cultures on scaffolds in animal models. Despite recent progress, there is much work to be done before the development of a functional artificial intestine for short bowel syndrome is successfully achieved.

SUMMARY

Continued concerted efforts by cell biologists, bioengineers, and clinician-scientists will be required for the development of an artificial intestine as a clinical treatment modality for short bowel syndrome.

The role of osmotic self-inflatable tissue expanders in intestinal transplant candidates

Intestinal transplantation (ITx) is often associated with decreased abdominal domain, rendering abdominal closure difficult. Pre-transplant placement of tissue expanders (TE) can overcome this challenge; however it can be associated with life-threatening complications. This review aimed to comprehensively summarize all available literature on TE in ITx candidates and include the technical details of osmotic, self-inflatable TE -a technique undescribed before. PubMed, EMBASE and CCTR were searched until April 30, 2016. Based on structured data abstraction and detailed analysis, eighteen cases of TE (inflatable) in ITx candidates were found. Localisation of placement was: subcutaneously in 11; intraperitoneally in 4; 1 patient had 1 TE placed retromuscularly and 1 intraperitoneally; 1 patient had biplanar TE (intraperitoneally placed and extending retromuscularly) and in 1 localisation was unreported. Complication rate was high (61%), injection- or intraperitoneal-related, resulting in life-threatening infections/hematoma. With successful expansion, physiological graft protection -by skin+/-fascia- was always achieved. In completion of this review, we describe our own experience with two patients (7.5-, 34-year-old females), in whom osmotic TE were placed subcutaneously pre-ITx. No TE-related complications occurred and both patients underwent uncomplicated ITx with respectively primary skin and skin + fascia closure. The pros and cons of each TE type and placement are discussed, resulting in the overall conclusions that TE offer an important benefit in graft-protection following ITx. Osmotic TE are safer than conventional prostheses by avoiding percutaneous injections. Subcutaneous placement seems to be safer and more reliable.

Management of Crohn's Disease in the New Era of Gut Rehabilitation and Intestinal Transplantation

Despite recent therapeutic advances, patients with Crohn's disease (CD) continue to experience high recurrence with cumulative structural damage and ultimate loss of nutritional autonomy. With short bowel syndrome, strictures, and enteric fistulae being the underlying pathology, CD is the second common indication for home parenteral nutrition (HPN). With development of intestinal failure, nutritional management including HPN is required as a rescue therapy. Unfortunately, some patients do not escape the HPN-associated complications. Therefore, the concept of gut rehabilitation has evolved as part of the algorithmic management of these patients, with transplantation being the ultimate life-saving therapy. With type 2 intestinal failure, comprehensive rehabilitative measures including nutritional care, pharmacologic manipulation, autologous reconstruction, and bowel lengthening is often successful, particularly in patients with quiescent disease. With type 3 intestinal failure, transplantation is the only life-saving treatment for patients with HPN failure and intractable disease. With CD being the second common indication for transplantation in adults, survival outcome continues to improve because of surgical innovation, novel immunosuppression, and better postoperative care. Despite being a rescue therapy, the procedure has achieved survival rates similar to other solid organs, and comparable to those who continue to receive HPN therapy. With similar technical, immunologic, and infectious complications, survival is similar in the CD and non-CD recipients. Full nutritional autonomy is achievable in most survivors with better quality of life and long-term cost-effectiveness. CD recurrence is rare with no impact on graft function. Further progress is anticipated with new insights into the pathogenesis of CD and mechanisms of transplant tolerance.

En Bloc Multivisceral and Kidney Transplantation in an HIV Patient: First Case Report

The continual improvement in outcome with highly active antiretroviral therapy (HAART) for human immunodeficiency virus (HIV) infection and visceral transplantation for gut failure stimulated our interest in lifting HIV infection as a contraindication for intestinal and multivisceral transplantation. This report is the first to describe visceral transplantation in a patient with HIV infection. A HAART regimen was introduced in the setting of short-gut syndrome with successful suppression of HIV viral load. The indication for en bloc multivisceral and kidney transplantation was end-stage liver failure with portomesenteric venous thrombosis and chronic renal insufficiency. The underlying hepatic pathology was alcoholic and home parenteral nutrition-associated cirrhosis. Surgery was complicated due to technical difficulties with excessive blood loss and long operative time. The complex posttransplant course included multiple exploratory laparotomies due to serious intra-abdominal and systemic infections. Heavy immunosuppression was required to treat recurrent episodes of severe allograft rejection. Posttransplant oral HAART successfully sustained undetectable viral load. Unfortunately, the patient succumbed to sepsis 3 months posttransplant. With new insights into the biology of gut immunity, mechanisms of allograft tolerance, and HIV-associated immune dysregulation, successful outcome is anticipated, particularly in patients who are in need of isolated intestinal and less-organ-contained visceral allografts.