Intestinal replacement therapy: timing and indications for referral of patients to an intestinal rehabilitation and transplant program

Innate and Adaptive Immune Responses in Intestinal Transplant Rejection: Through the Lens of Inflammatory Bowel and Intestinal Graft-Versus-Host Diseases

Intestinal transplantation is a life-saving procedure utilized for patients failing total parenteral nutrition. However, intestinal transplantattion remains plagued with low survival rates and high risk of allograft rejection. The authors explore roles of innate (macrophages, natural killer cells, innate lymphoid cells) and adaptive immune cells (Th1, Th2, Th17, Tregs) in inflammatory responses, particularly inflammatory bowel disease and graft versus host disease, and correlate these findings to intestinal allograft rejection, highlighting which effectors exacerbate or suppress intestinal rejection. Better understanding of this immunology can open further investigation into potential biomolecular targets to develop improved therapeutic treatment options and immunomonitoring techniques to combat allograft rejection and enhance patient lives.

Intestinal Rehabilitation Program for Adult Patients with Intestinal Failure: A 20-Year Analysis of Outcomes in the Single-Center Experience at a Tertiary Hospital

BACKGROUND & AIMS

The intestinal rehabilitation program (IRP) is a specialized approach to managing patients with intestinal failure (IF). The goal of IRP is to reduce the patient's dependence on parenteral nutrition by optimizing nutrition intake while minimizing the risk of complications and providing individualized medical and surgical treatment. We aimed to provide a thorough overview of our extensive history in adult IRP.

METHODS

We reviewed the medical records of adults with IF treated at our center's IRP over the past two decades. We collected data on demographic and clinical results, such as the causes of IF, the current status of the remaining bowel, nutritional support, and complications or mortality related to IF or prolonged parenteral nutrition.

RESULTS

We analyzed a total of 47 adult patients with a median follow-up of 6.7 years. The most common cause of IF was massive bowel resection due to mesenteric vessel thrombosis (38.3%). Twenty-eight patients underwent rehabilitative surgery, including 12 intestinal transplants. The 5-year survival rate was 81.9% with 13 patients who expired due to sepsis, liver failure, or complication after transplantation. Of the remaining 34 patients, 18 were successfully weaned off from parenteral nutrition.

CONCLUSION

Our results of IRP over two decades suggest that the individualized and multidisciplinary program for adult IF is a promising approach for improving patient outcomes and achieving nutritional autonomy.

Nutrition in intestinal transplantation: centre stage or supporting act?

PURPOSE OF REVIEW

Intestinal transplantation (ITx), whether isolated or combined with other organs, is now a valid treatment option in some patients with chronic intestinal failure or extensive venous mesenteric thrombosis. The aim in these patients is not only to restore nutritional autonomy, but also to minimize the risk of complications, both short and long term. Despite parenteral nutrition playing a central part in the management of intestinal failure patients, there are little data about the perioperative and postoperative nutritional management of ITx patients, due to small patient populations per centre. In this review, we collected the scientific data available to date.

RECENT FINDINGS

In this review, we will bundle the limited scientific information about diet after intestinal and multivisceral transplantation combined with recommendations from our own clinical practice in 28 ITx patients in University Hospitals Leuven, Belgium. We will discuss the immediate preoperative period, surgical complications necessitating dietary interventions and the late postoperative phase in a stable outpatient transplant recipient.

SUMMARY

Although no specific research has been done in the field of ITx, we can extrapolate some findings from other solid organ transplants. Prehabilitation might prove to be of importance; Preserving kidney and liver function in the pretransplant period should be pursued. Transition from parenteral to enteral and oral nutrition can be complex due to inherent surgical procedures and possible complications. Ultimately, the goal is to give patients nutritional autonomy, while also minimizing the risk of foodborne infections by teaching patients well tolerated food practices.

Serotonin as a Mitogen in the Gastrointestinal Tract: Revisiting a Familiar Molecule in a New Role

Serotonin signaling is ubiquitous in the gastrointestinal (GI) system, where it acts as a neurotransmitter in the enteric nervous system (ENS) and influences intestinal motility and inflammation. Since its discovery, serotonin has been linked to cellular proliferation in several types of tissues, including vascular smooth muscle, neurons, and hepatocytes. Activation of serotonin receptors on distinct cell types has been shown to induce well-known intracellular proliferation pathways. In the GI tract, potentiation of serotonin signaling results in enhanced intestinal epithelial proliferation, and decreased injury from intestinal inflammation. Furthermore, activation of the type 4 serotonin receptor on enteric neurons leads to neurogenesis and neuroprotection in the setting of intestinal injury. It is not surprising that the mitogenic properties of serotonin are pronounced within the GI tract, where enterochromaffin cells in the intestinal epithelium produce 90% of the body's serotonin; however, these proliferative effects are attributed to increased serotonin signaling within the ENS compartment as opposed to the intestinal mucosa, which are functionally and chemically separate by virtue of the distinct tryptophan hydroxylase enzyme isoforms involved in serotonin synthesis. The exact mechanism by which serotonergic neurons in the ENS lead to intestinal proliferation are not known, but the activation of muscarinic receptors on intestinal crypt cells indicate that cholinergic signaling is essential to this signaling pathway. Further understanding of serotonin's role in mucosal and enteric nervous system mitogenesis may aid in harnessing serotonin signaling for therapeutic benefit in many GI diseases, including inflammatory bowel disease, malabsorptive conditions, and cancer.

Rejection of intestinal allotransplants is driven by memory T helper type 17 immunity and responds to infliximab

Intestinal transplantation (ITx) can be life-saving for patients with advanced intestinal failure experiencing complications of parenteral nutrition. New surgical techniques and conventional immunosuppression have enabled some success, but outcomes post-ITx remain disappointing. Refractory cellular immune responses, immunosuppression-linked infections, and posttransplant malignancies have precluded widespread ITx application. To shed light on the dynamics of ITx allograft rejection and treatment resistance, peripheral blood samples and intestinal allograft biopsies from 51 ITx patients with severe rejection, alongside 37 stable controls, were analyzed using immunohistochemistry, polychromatic flow cytometry, and reverse transcription-PCR. Our findings inform both immunomonitoring and treatment. In terms of immunomonitoring, we found that while ITx rejection is associated with proinflammatory and activated effector memory T cells in the blood, evidence of treatment efficacy can only be found in the allograft itself, meaning that blood-based monitoring may be insufficient. In terms of treatment, we found that the prominence of intra-graft memory TNF-α and IL-17 double-positive T helper type 17 (Th17) cells is a leading feature of refractory rejection. Anti-TNF-α therapies appear to provide novel and safer treatment strategies for refractory ITx rejection; with responses in 14 of 14 patients. Clinical protocols targeting TNF-α, IL-17, and Th17 warrant further testing.

Type 3 innate lymphoid cells are associated with a successful intestinal transplant

Although innate lymphoid cells (ILCs) play fundamental roles in mucosal barrier functionality and tissue homeostasis, ILC-related mechanisms underlying intestinal barrier function, homeostatic regulation, and graft rejection in intestinal transplantation (ITx) patients have yet to be thoroughly defined. We found protective type 3 NKp44⁺ ILCs (ILC3s) to be significantly diminished in newly transplanted allografts, compared to allografts at 6 months, whereas proinflammatory type 1 NKp44^- ILCs (ILC1s) were higher. Moreover, serial immunomonitoring revealed that in healthy allografts, protective ILC3s repopulate by 2-4 weeks postoperatively, but in rejecting allografts they remain diminished. Intracellular cytokine staining confirmed that NKp44⁺ ILC3 produced protective interleukin-22 (IL-22), whereas ILC1s produced proinflammatory interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Our findings about the paucity of protective ILC3s immediately following transplant and their repopulation in healthy allografts during the first month following transplant were confirmed by RNA-sequencing analyses of serial ITx biopsies. Overall, our findings show that ILCs may play a key role in regulating ITx graft homeostasis and could serve as sentinels for early recognition of allograft rejection and be targets for future therapies.

Intestinal failure in adults and children

Intestinal failure (IF) is rare, but it represents one of the most complex medical-surgical management pathologies, both in adults and children. The first-line treatment is parenteral nutrition (PN). However, new alternatives in the field of intestinal rehabilitation have opened up in recent decades, with the rise of multidisciplinary teams and the development of new hormone therapies as the first non-symptomatic approach to IF.

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.

Visceral transplantation in patients with intestinal-failure associated liver disease: Evolving indications, graft selection, and outcomes

Intestinal failure (IF)-associated liver disease (IFALD) is widely recognized as a lethal complication of long-term parenteral nutrition. The pathophysiology of IFALD is poorly understood but appears to be multifactorial and related to the inflammatory state in the patient with IF. Visceral transplant for IFALD includes variants of intestine, liver, or combined liver-intestine allografts. Graft selection for an individual patient depends on the etiology of IF, abdominal and vascular anatomy, severity of IFALD, and potential for intestinal rehabilitation. The past decade has witnessed dramatic improvement in the management of IFALD, principally due to improved lipid emulsion formulations and the multidisciplinary care of the patient with IF. As the recognition and treatment of IFALD continue to improve, the requirement of liver-inclusive visceral grafts appears to be decreasing, representing a paradigm shift in the care of the patient with IF. This review highlights the current indications, graft selection, and outcomes of visceral transplantation for IFALD.

The use of vascular homografts in pediatric small bowel transplantation: Single-center experience over a decade

Intestinal transplantation in children has evolved with more isolated small intestine transplants being performed compared to combined liver-intestine transplants. Consequently, surgical techniques have changed, frequently requiring the use of vascular homografts of small caliber to revascularize the isolated small intestine, the impact of which on outcomes is unknown. Among 106 pediatric intestine and multivisceral transplants performed at our center since 2003, 33 recipients of an isolated small intestine graft were included in this study. Outcome parameters were thrombotic complications, graft, and patient survival. A total of 29 of 33 (87.9%) patients required arterial and/or venous homografts from the same donor, mainly iliac or carotid artery and iliac or innominate vein, respectively (donor's median age 1.1 years [2 months to 23 years], median weight 10 kg [14.7-48.5]). Post-transplant, there were three acute arterial homograft thromboses and one venous thrombosis resulting in two peri-operative graft salvages and two graft losses. Three of four thromboses occurred in patients with primary hypercoagulable state, including the two graft losses. Overall, at a median of 4.1 years (1-10.2) from transplant, 29 of 33 (88%) patients are alive with 26 of 33 (79%) functioning grafts. The procurement of intact, size-matched donor vessels and the management of effective post-transplant anticoagulation are critical.

Intestinal Rehabilitation Programs in the Management of Pediatric Intestinal Failure and Short Bowel Syndrome

Intestinal failure is a rare, debilitating condition that presents both acute and chronic medical management challenges. The condition is incompatible with life in the absence of the safe application of specialized and individualized medical therapy that includes surgery, medical equipment, nutritional products, and standard nursing care. Intestinal rehabilitation programs are best suited to provide such complex care with the goal of achieving enteral autonomy and oral feeding with or without intestinal transplantation. These programs almost all include pediatric surgeons, pediatric gastroenterologists, specialized nurses, and dietitians; many also include a variety of other medical and allied medical specialists. Intestinal rehabilitation programs provide integrated interdisciplinary care, more discussion of patient management by involved specialists, continuity of care through various treatment interventions, close follow-up of outpatients, improved patient and family education, earlier treatment of complications, and learning from the accumulated patient databases. Quality assurance and research collaboration among centers are also goals of many of these programs. The combined and coordinated talents and skills of multiple types of health care practitioners have the potential to ameliorate the impact of intestinal failure and improve health outcomes and quality of life.

Intestinal transplantation

Intestinal transplantation has now emerged as a lifesaving therapeutic option and standard of care for patients with irreversible intestinal failure. Improvement in survival over the years has justified expansion of the indications for intestinal transplantation beyond the original indications approved by Center for Medicare and Medicaid services. Management of patients with intestinal failure is complex and requires a multidisciplinary approach to accurately select candidates who would benefit from rehabilitation versus transplantation. Significant strides have been made in patient and graft survival with several advancements in the perioperative management through timely referral, improved patient selection, refinement in the surgical techniques and better understanding of the immunopathology of intestinal transplantation. The therapeutic efficacy of the procedure is well evident from continuous improvements in functional status, quality of life and cost-effectiveness of the procedure. This current review summarizes various aspects including current practices and evidence based recommendations of intestinal transplantation.

Intestinal and multivisceral transplantation

Intestinal transplantation has shown exceptional growth over the past 10 years. At the end of the 1990’s, intestinal transplantation moved out of the experimental realm to become a routine practice in treating patients with severe complications related to total parenteral nutrition and intestinal failure. In the last years, several centers reported an increasing improvement in survival outcomes (about 80%), during the first 12 months after surgery, but long-term survival is still a challenge. Several advances led to clinical application of transplants. Immunosuppression involved in intestinal and multivisceral transplantation was the biggest gain for this procedure in the past decade due to tacrolimus, and new inducing drugs, mono- and polyclonal anti-lymphocyte antibodies. Despite the advancement of rigid immunosuppression protocols, rejection is still very frequent in the first 12 months, and can result in long-term graft loss. The future of intestinal transplantation and multivisceral transplantation appears promising. The major challenge is early recognition of acute rejection in order to prevent graft loss, opportunistic infections associated to complications, post-transplant lymphoproliferative disease and graft versus host disease; and consequently, improve results in the long run.

The current state of intestine transplantation: indications, techniques, outcomes and challenges

Intestine transplantation is the least common form of organ transplantation in the United States and often deemed one of the most difficult. Patient and graft survival have historically trailed well behind other organ transplants. Over the past 5-10 years registry reports and single center series have demonstrated improvements to patient survival after intestinal transplantation that now match patient survival for those without life-threatening complications on parenteral nutrition. For various reasons including improvements in medical care of patients with intestinal failure and difficulty accessing transplant care, the actual number of intestine transplants has declined by 25% over the past 6 years. In light of the small numbers of intestine transplants, many physicians and the lay public are often unaware that this is a therapeutic option. The aim of this review is to describe the current indications, outcomes and advances in the field of intestine transplantation and to explore concerns over future access to this important and life-saving therapy.

Intestinal Transplantation from Living Donors

Intestinal transplantation (ITx) represents the physiologic alternative to total parenteral nutrition (TPN) for patients suffering from life-threatening complications of irreversible intestinal failure. The number of transplants performed worldwide has been increasing for several years until recently. ITx has recently become a valid therapeutic option with a graft survival rate between 80 % and 90 % at 1 year, in experienced centers. These results have been achieved due to a combination of several factors: better understanding of the pathophysiology of intestinal graft, improved immunosuppression techniques, more efficient strategies for the monitoring of the bowel graft, as well as control of infectious complications and posttransplant lymphoproliferative disease (PTLD). In fact, this procedure is associated with a relatively high rate of complications, such as infections, acute rejection, graft versus host disease (GVHD), and PTLD, if compared to the transplantation of other organs. These complications may be, at least in part, the consequence of the peculiarity of this graft, which contains gut-associated lymphoid tissue and potentially pathogenic enteric flora. Furthermore, in these patients, the existing disease and the relative malnutrition could predispose them to infectious complications. Additionally, other factors associated with the procedure, such as laparotomy, preservation injury, abnormal motility, and lymphatic disruption, could all be implicated in the development of complications.

Life-threatening risk factors and the role of intestinal transplantation in patients with intestinal failure

PURPOSE

We elucidated the life-threatening risk factors for intestinal failure (IF) and characterized the role of intestinal transplantation (ITx) in affected patients.

METHODS

We conducted a retrospective review of 38 patients with short bowel (SB) and 19 with motility disorders (MD). The SB patients were divided into three categories according to the length of their residual small bowel and the presence of the ileocecal valve. The four disease subcategories were grouped into two categories: low-risk category (mild and moderated SB) and high-risk category (extensive SB and MD). The age at the introduction of parenteral nutrition (PN) was <1 year in 50 patients (infant group, IG) and 1-15 years in 7 patients (pediatric group, PG).

RESULTS

Enteral autonomy was rarely achieved in the high-risk category (p < 0.0001). IG was associated with a higher incidence of developing intestinal failure-associated liver disease (IFALD) (p = 0.004). Eight patients died, due to IFALD in four, sepsis in three and acute heart failure in one. Twenty-eight patients (49 %) are currently alive without PN, including four after ITx.

CONCLUSION

The treatment of high-risk IF is still challenging. Inclusion of ITx in appropriate timing, along with aggressive medical, nutritional and surgical management, may reduce advanced morbidity and mortality of high-risk IF.

Nucleotide oligomerization domain 2 polymorphisms in patients with intestinal failure

BACKGROUND

Nucleotide oligomerization domain 2 (NOD2) has been associated with intestinal immunity after the discovery that its polymorphisms are linked to Crohn's disease (CD). Intestinal failure (IF) represents a wider spectrum of diseases where intestinal homeostasis has been disrupted.

AIM

To evaluate the prevalence of NOD2 mutations in a population with IF as well as its association with the different conditions causing this problem.

METHODS

One hundred ninety-two consecutive patients with IF and 103 healthy controls were genotyped for the three most common NOD2 polymorphisms. Genotypes were compared between the groups and were related to the entities causing IF.

RESULTS

A high percentage (26%) of patients had at least one of the three most common NOD2 polymorphisms, while only a 4.8% of healthy controls had a mutant genotype. In patients with IF, specific mutations for the 702W, 908R and 1007fs alleles were 11, 5 and 12.5%, respectively, compared with 0.9% (P = 0.0003), 1.9% (P = 0.1) and 1.9% (P = 0.001) in the control group. If we consider patients with any cause of IF other than CD, the percentage is still as high as 18.8%, with specific mutation frequencies of 7.6% (702W; P = 0.01), 5.8% (908R; P = 0.1) and 8.2% (1007fs; P = 0.002). We could not establish an association between a NOD2 mutant genotype with any other specific clinical condition other than CD.

CONCLUSION

Our finding supports the importance of NOD2 in the maintenance of intestinal immune homeostasis and may be important to a variety of intestinal stressors.

Isolated intestinal transplantation for megacystis microcolon intestinal hypoperistalsis syndrome: case report

MMIHS is a rare congenital disease. It is characterized by distended urinary bladder, small colon and intestinal hypoperistalsis, or aperistalsis with normal morphology. There is no specific treatment for MMIHS, and most patients have to be maintained by TPN, which frequently causes TPN-related liver failure, loss of venous access, or catheter-related sepsis. The prognosis of patients with MMIHS is poor, and most patients die early. Multivisceral transplantation including stomach, duodenum, intestine, and liver has been used for the treatment of patients with MMIHS because these patients often have liver failure. We report an eight-yr-old patient with MMIHS who was treated with isolated intestinal transplantation. She had completely oral intake during the four yr of follow-up. The experience in this case suggests isolated intestinal transplantation may be indicated in selected cases with MMIHS.

Waitlist characteristics of patients at a single-center intestinal and multivisceral transplant program

Intestinal transplantation (ITX) can be a successful treatment for patients with irreversible intestinal failure and associated severe complications. Because of long waiting periods and organ shortages, the precise identification of eligible patients and their early referral to centers that perform ITX is important. We retrospectively analyzed all patients who were referred to our center between 2000 and 2011 concerning their referral criteria, waitlist characteristics, and outcome. A total of 87 patients (47 male patients, 40 female patients; median age 39.8 ± 13.4 years) were referred to our center. All patients presented with intestinal failure caused by short bowel syndrome or motility disorders. About 80.5% of patients were evaluated for isolated ITX, modified multivisceral (mMVTX), or multivisceral transplantation (MVTX). About 56.3% were listed at EUROTRANSPLANT, 33.3% suffered from severe secondary organ failure requiring MVTX, and 34.5% were transplanted. 14.3% (all MVTX-candidates) died on the waitlist as a result of infectious complications. The high proportion of MVTX candidates underlines the need for early referral to specialized centers. MVTX-candidates have a high waitlist mortality for different reasons. However, the current allocation policy for MVTX does not mirror the severity of disease and may therefore contribute to high waitlist mortality.

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.

The impact of MELD/PELD revisions on the mortality of liver-intestine transplantation candidates

Patients listed for liver-intestine transplantation suffer higher waiting list mortality than those listed for liver-only, thus leading to policy revisions seeking to close the gap. We sought to determine the impact of key model for end-stage liver disease (MELD)/pediatric end-stage liver disease (PELD) policy modifications on the waiting list mortality of adult and pediatric liver-intestine candidates as compared to liver-only candidates. Analysis of UNOS data separated into adult and pediatric categories and based on time periods of policy implementation revealed higher mortality in liver-intestine candidates over all time periods studied (p < 0.001 pediatric and adult). After implementation of a revision to augment their MELD scores based on a sliding scale, adult liver-intestine candidates with calculated MELD > 15 no longer suffered higher mortality although this change did not completely eliminate the mortality disparity for candidates with MELD < 15 (p < 0.01). The waiting list mortality of pediatric liver-intestine candidates dropped significantly after a revision that gave them 23 additional MELD/PELD points (p < 0.01) although the mortality disparity with pediatric liver-only candidates was not eliminated. Following this revision, mortality in pediatric liver-only and liver-intestine Status 1 candidates was similar, however more liver-intestine candidates were listed as Status 1B. This data demonstrates that a mortality disparity remains for liver-intestine candidates compared with candidates listed for liver-only.

Intestinal transplantation: current status and future directions

Three decades after the first intestinal transplant was performed in humans, this life-saving procedure has come of age and now offers hope of long-term survival in a small group of patients with life-threatening complications of intestinal failure and parenteral nutrition. Success rates have greatly improved, largely through advances in immunosuppression protocols, improved surgical technique and postoperative care, and accumulated experience. Management of the intestinal transplant recipient entails careful surveillance, prevention, and treatment of rejection and infection, as well as optimization of feeding and nutrition. With this approach, survival and quality of life are demonstrably improved, such that intestinal transplantation is now an established and accepted procedure for this very select group of highly-complex patients.

Use of the aspartate aminotransferase to platelet ratio index to follow liver fibrosis progression in infants with short gut

BACKGROUND

Infants with parenteral nutrition dependence may develop liver dysfunction and progress to liver failure requiring transplantation. The aspartate aminotransferase-to-platelet ratio index (APRI) has good correlation with liver fibrosis progression in adults. This study applies APRI scoring to parenteral nutrition-dependant, short-gut infants to determine hepatic fibrosis progression.

METHODS

Laboratory values and biopsies were collected from initial intestinal resection (time 0) up to transplantation (end). Fibrosis scoring ranged from F0 (normal) to F4 (cirrhosis). Children were divided into 3 groups: (1) isolated intestine; and combined liver/intestine with gestational age (2) 34 weeks or greater and (3) 30 weeks or less. Liver function values over time, including calculated APRI, were analyzed as predictors of fibrosis.

RESULTS

Fifteen children who had 33 biopsies were included. Median APRI by fibrosis grade was F < or = 2: 1.88, F3: 3.23, and F4: 14.16 (P < .01). Median APRI at transplant by study group was (1) isolated intestine: 2.47, (2) liver/intestine 35 weeks or longer EGA: 14.16, and (3) liver/intestine 30 weeks or less EGA: 14.74 (P = .04).

CONCLUSION

Progression of APRI up to 60 days initially demonstrates similar values among study groups, but over time the score distinguishes those children with impending liver cirrhosis and differentiates fibrosis grade and study group.

How immunocompromised are short bowel patients receiving home parenteral nutrition? Apropos a case of disseminated Fusarium oxysporum sepsis

BACKGROUND

Catheter-related sepsis is the most frequent complication in patients receiving home parenteral nutrition (HPN) for short bowel syndrome (SBS). A low-grade systemic inflammatory state and an altered mucosal immune response, as well as diminished intestinal barrier function have been characterized in these patients. The possibility of systemic immunocompromise has only recently been suggested.

CASE DESCRIPTION

A 45-year-old female with traumatic SBS was admitted for possible catheter-related sepsis. She was asplenic and had insulin-dependent diabetes mellitus as a result of a pancreatic resection. A large skin ulceration was present on her left calf, which appeared unusual for a disseminated bacterial infection. Chest x-ray and computed tomography scan revealed multiple subpleural pulmonary infiltrates consistent with bacterial or fungal dissemination. Blood cultures from the port system and from the peripheral blood grew Staphylococcus haemolyticus and Fusarium oxysporum. The port system was removed, and flucloxacillin and voriconazole were given for 33 and 35 days, respectively. Clinical signs of disseminated sepsis resolved slowly. Bone marrow biopsy ruled out primary hematologic disease.

CONCLUSIONS

(1) Catheter-related sepsis in patients on HPN is usually caused by Gram-positive or Gram-negative bacteria or by Candida species. Identification of molds in blood cultures strongly suggests Fusarium species, which should be treated appropriately with voriconazole or amphotericin B. (2) HPN and SBS aggravated by asplenism and diabetes mellitus can cause severe immunocompromise. (3) Fusaria have a strong tendency to persist or reappear after bone marrow transplantation, which is therefore relatively contraindicated in these patients.

Human gut microbiome adopts an alternative state following small bowel transplantation

Small bowel transplants provide an exceptional opportunity for long-term study of the microbial ecology of the human small bowel. The ileostomy created at time of transplant for ongoing monitoring of the allograft provides access to samples of ileal effluent and mucosal biopsies. In this study, we used qPCR to assay the bacterial population of the small bowel lumen of 17 small bowel transplant patients over time. Surprisingly, the posttransplant microbial community was found to be dominated by Lactobacilli and Enterobacteria, both typically facultative anaerobes. This represents an inversion of the normal community that is dominated instead by the strictly anaerobic Bacteroides and Clostridia. We found this inverted community also in patients with ileostomies who did not receive a transplant, suggesting that the ileostomy itself is the primary ecological determinant shaping the microbiota. After surgical closure of the ileostomy, the community reverted to the normal structure. Therefore, we hypothesized that the ileostomy allows oxygen into the otherwise anaerobic distal ileum, thus driving the transition from one microbial community structure to another. Supporting this hypothesis, metabolomic profiling of both communities demonstrated an enrichment for metabolites associated with aerobic respiration in samples from patients with open ileostomies. Viewed from an ecological perspective, the two communities constitute alternative stable states of the human ileum. That the small bowel appears to function normally despite these dramatic shifts suggests that its ecological resilience is greater than previously realized.

Present prospects and future perspectives of intestinal and multivisceral transplantation

PURPOSE OF REVIEW

This article reviews the most current indications, technical aspects and results of intestinal and multivisceral transplantation.

RECENT FINDINGS

The introduction of induction therapy in the past 8 years, combined with advancements on surgical technique and clinical management, was vital for the improvement in patient and graft survival.

SUMMARY

Intestinal transplantation is now a viable option for patients with intestinal failure who have failed parenteral nutrition. The improvement in the survival of intestinal and multivisceral transplant recipients has extended its use to selected patients with neoplastic disease, extensive splanchnic thrombosis and abdominal catastrophes.

Liver and intestine transplantation in the United States 1998-2007

Liver transplantation numbers in the United States remained constant from 2004 to 2007, while the number of waiting list candidates has trended down. In 2007, the waiting list was at its smallest since 1999, with adults > or =50 years representing the majority of candidates. Noncholestatic cirrhosis was most commonly diagnosed. Most age groups had decreased waiting list death rates; however, children <1 year had the highest death rate. Use of liver allografts from donation after cardiac death (DCD) donors increased in 2007. Model for end-stage liver disease (MELD)/pediatric model for end-stage liver disease (PELD) scores have changed very little since 2002, with MELD/PELD <15 accounting for 75% of the waiting list. Over the same period, the number of transplants for MELD/PELD <15 decreased from 16.4% to 9.8%. Hepatocellular carcinoma exceptions increased slightly. The intestine transplantation waiting list decreased from 2006, with the majority of candidates being children <5 years old. Death rates improved, but remain unacceptably high. Policy changes have been implemented to improve allocation and recovery of intestine grafts to positively impact mortality. In addition to evaluating trends in liver and intestine transplantation, we review in depth, issues related to organ acceptance rates, DCD, living donor transplantation and MELD/PELD exceptions.

Pediatric intestinal retransplantation: techniques, management, and outcomes

BACKGROUND

Intestinal retransplantation (Re-ITx) has historically been associated with high morbidity and mortality.

METHODS

The outcomes of all children receiving Re-ITx between 1990 and 2007 at our center were reviewed.

RESULTS

One hundred seventy-two children received primary intestinal grafts. Fourteen children (8.1%) were retransplanted with 15 grafts. Causes of graft failure were acute cellular rejection (ACR, n=4), liver failure (n=2), chronic rejection (n=3), posttransplant lymphoproliferative disorder (n=1), graft dysmotility or dysfunction (n=3), ACR with severe infection (n=1), and arterial graft aneurysm (n=1). Initial transplants were isolated bowel in nine, liver-bowel in five, and one multivisceral. The mean time of initial graft survival was 34.2 months. Re-ITx was with isolated bowel in two, liver-bowel in four, and multivisceral in nine (four with kidney). Initial immunosuppression was Tac-Pred based in nine and rabbit antithymocyte globulin-Tac based in six cases. Re-ITx was carried out under Tac-Pred in six, rabbit antithymocyte globulin-Tac in eight, and alemtuzumab monoclonal anti-CD52 antibody in one. Ten (71.4%) patients are alive with functioning grafts at a mean current follow-up time of 55.9 months. Four patients died from posttransplant lymphoproliferative disorder, severe ACR, fungal sepsis, and bleeding from pseudoaneurysm, respectively, at a mean time of 5.7 months post-Re-ITx. All surviving patients weaned-off total parenteral nutrition at a median time of 32 days and 90% are off intravenous fluids.

CONCLUSIONS

Improved long-term survival and outcome in pediatric Re-ITx may be attributed to improvements in initial immunosuppression protocols, technical modifications, proper timing, and improved infectious disease monitoring. Careful patient selection and posttransplant management are essential for successful long-term outcome.

Current status of small bowel and multivisceral transplantation

Intestinal transplantation has shown exceptional growth over the past 20 years with remarkable progress. As with other solid organ transplants, intestinal transplantation has moved out of the experimental realm to become the stan dard of care for many patients with intestinal failure. Intestinal transplantation may soon be extended routinely to patients who, although not strictly meeting the criteria for intestinal failure, may benefit from intestinal transplantation, such as patients who have nonresectable indolent tumors or diffuse thrombosis of the portomesenteric system. As clinical experience has increased with intestinal transplantation, outcomes have improved. The currently reported 1-year graft and patient survival rate is 80%, which approaches that for other solid abdominal organs. Unfortunately, most of the gains in survival are seen in the first postoperative year, with long-term survival remaining basically unchanged since the early 1990s. With improved outcomes, more centers have entered into the intestinal transplant arena. In the United States alone, 20 centers performed at least one intestinal transplant in 2007. Increase in access to intestinal transplantation and more widespread awareness of this option likely will result in a consistent increase in the number of yearly transplants for the foreseeable future. Immunosuppressive regimens continue to evolve, with induction therapy being the major change in the past 5 years. Although rejection rates in the first year after transplant have been reduced by induction therapy, long-term side effects of heavy immunosuppression continue to weigh negatively on transplant outcomes. The future for immunosuppression lies in two areas: (1) individual monitoring of the immunosuppression level for each individual patient and (2) development of serum and tissue markers for the early identification of rejection. It is likely that a combination of technologies will allow immunosuppression to be tailored to each recipient. Development of these approaches to immunosuppression is necessary to predict graft dysfunction ahead of irreversible graft injury and allows adjustments in immunosuppression before the onset of rejection. Intestinal transplantation continues to be performed only in situations in which all other therapeutic modalities have failed. No randomized trials compare intestinal transplantation to long-term PN to establish guidelines for a timely referral for this treatment option. Late referral remains a crippling problem in the field of intestinal transplantation, with a great number of patients in need of simultaneous liver transplantation at the time of listing for intestinal transplantation. Early referral for isolated intestinal transplant will reduce the need for simultaneous multiorgan transplants and increase the residual organs available for patients in need of (primarily) liver transplantation.

Collaborative strategies to reduce mortality and morbidity in patients with chronic intestinal failure including those who are referred for small bowel transplantation

Intestinal transplant wait-list mortality is higher than for other organ transplants. The objective of this workshop was to identify the main problems contributing to high mortality in adults and children candidates for intestinal transplantation and provide recommendations on how to correct them.

OUTCOME

To facilitate this, 63 relevant articles identified from the medical literature from 1987 to 2007 were reviewed. Consensus was achieved on several important definitions relevant to this review. For children and adults on parenteral nutrition (PN) the main mortality risk factors were identified as were the main risks of mortality for those on the waiting list for intestinal transplants.

RECOMMENDATIONS

(1) Primary care givers managing intestinal failure patients should establish a link with an intestinal failure programs early and collaboration with intestinal failure programs should be initiated for patients whose PN requirements are anticipated to be more than 50% 3 months after initiating PN; (2) intestinal failure programs should include both intestinal rehabilitation and intestinal transplantation or have active collaborative relationships with centers performing intestinal transplantation; (3) National registries for intestinal failure patients should be established and organizations that provide home PN solutions should be expected to participate.

CONCLUSION

There are many unresolved issues in adults and children with PN dependent intestinal failure. To address these, a key recommendation of this group is to establish national intestinal failure databases that can support multicenter studies and lead to the adoption of universally accepted standards of patient care with the goal of improving outcomes in all long-term intestinal failure patients including those requiring intestinal transplantation.

Nutrition and quality of life following small intestinal transplantation

BACKGROUND

The outcome from small bowel transplantation (SBTx) has improved progressively over the past decade raising questions as to whether indications should be broadened from those currently followed based on "TPN (total parenteral nutrition) failure."

OBJECTIVE AND METHODS

To assess current outcome, we studied the effect of transplantation on nutritional autonomy, organ function, and quality of life (QoL) measured by a validated self-administered questionnaire containing 26 domains and 130 questions, for a minimum of 12 months in a cohort of 46 consecutively transplanted patients between June 2003 and July 2004. The majority of transplanted patients (76%) had intestinal failure because of extreme short bowel, the remainder having either chronic pseudo-obstruction or porto-mesenteric vein thrombosis (PMVT). All but the PMVT patients were dependent on home TPN (HPN) (median 2, range 0-25 yr) and had developed serious recurrent infective complications with (25%) or without central vein thrombosis and liver failure. Sixty-one percent received a liver in addition to a small intestine.

RESULTS

Follow-up was for a mean of 21 (range 12-36) months. Five patients died, two with chronic graft rejection. All the remaining patients have graft survival with an average of 1.2 (range 0-5) episodes of acute rejection. All patients were weaned from TPN by a median of 18 days (range 1-117 days) and from tube feeding by day 69 (range 22-272 days). There was a significant improvement in overall assessment of QoL and in 13 of 26 of the specific domains examined.

CONCLUSION

Our results confirm the claim that a new era has dawned for SBTx, such that, with continued progress, it can potentially become an alternative to HPN for the management of permanent intestinal failure, rather than a last-chance treatment for "TPN failure."

Small bowel transplantation

Until very recently, outcomes from small bowel transplantation (SBTx) lagged behind those in liver, heart, and kidney transplantation because of the magnitude of the immunologic burden; the strong expression of histocompatibility antigens; and the contamination in grafts by bacterial organisms. With novel techniques of immune-induction therapies, such as recipient "preconditioning" with lymphocyte reduction, followed by the more subtle use of immunosuppression-based single-agent tacrolimus, graft and host 1-year survival is now over 90% in the most active US centers, a finding that parallels the outcomes in liver and kidney transplantation. In contrast to the alternative therapy for permanent intestinal failure, home total parenteral nutrition (TPN), SBTx improves quality of life and restores digestive and absorptive function, making patients nutritionally autonomous. With survival beyond 1 to 3 years, the procedure is cost-effective. Current results support expansion of the indications for SBTx from use as salvage therapy for patients with TPN failure to preemptive therapy for patients at risk of developing TPN failure.