Clinical intestinal transplantation: a decade of experience at a single center

Innovative surgical techniques in the intestine and multivisceral transplant

PURPOSE OF REVIEW

This timely review delves into the evolution of multivisceral transplantation (MVT) over the past six decades underscoring how advancements in surgical techniques and immunosuppression have driven transformation, to provide insight into the historical development of MVT, shedding light on its journey from experimentation to a valuable clinical approach.

RECENT FINDINGS

The review presents contemporary enhancements in surgical methods within the context of intestinal transplantation. The versatility of MVT is emphasized, accommodating diverse organ combinations and techniques. Both isolated intestinal transplantation (IIT) and MVT have seen expanded indications, driven by improved parenteral nutrition, transplantation outcomes, and surgical innovations. Surgical techniques are tailored based on graft type, with various approaches for isolated transplantation. Preservation strategies and ostomy techniques are also covered, along with graft assessment advancements involving donor-specific antibodies.

SUMMARY

This review's findings underscore the remarkable evolution of MVT from experimental origins to a comprehensive clinical practice. The progress in surgical techniques and immunosuppression has broadened the spectrum of patients who can benefit from intestinal transplant, including both IIT and MVT. The expansion of indications offers hope to patients with complex gastrointestinal disorders. The detection of donor-specific antibodies in graft assessment advances diagnostic accuracy, ultimately improving patient outcomes.

Timing and Complications of Intestinal Ostomy Takedown After Intestinal and Multivisceral Transplantation

BACKGROUND

Ileostomies are typically created at the time of intestinal and multivisceral transplantation to assist in graft monitoring with endoscopy and biopsies. Often, these ostomies are reversed with a takedown procedure once there is stable graft function, but data are limited on associated complications of the takedown procedure for patients with intestinal transplants.

METHODS

To assess complications associated with takedowns in this patient population, we performed a retrospective analysis of patients who had an intestinal transplant with elective ostomy takedown after transplant. No prisoners were used in the study and this manuscript is in compliance with the Helsinki Congress and the Declaration of Istanbul.

RESULTS

A total of 16 patients, 10 isolated patients with intestinal transplants and 6 patients with multivisceral transplants, were included in the study, and takedown occurred at a mean of (236.8 ± 117.1) days after transplant. Of the 16 patients, 5 patients (31%) had uncomplicated courses after takedown with no infection, no rejection, and no hospital readmission within 3 months of takedown. The rest of the patients (69%) developed either infection or rejection within 3 months of takedown, and 1 patient died of infection after ileostomy takedown.

CONCLUSION

This case series highlights the high risk of complications after ileostomy takedown for patients with intestinal transplants and contributes to the growing debate regarding the role of ileostomy creation and reversal in patients with intestinal transplants.

Liver Inclusion Appears to Be Protective Against Graft Loss-Due-to Chronic But Not Acute Rejection Following Intestinal Transplantation

In intestinal transplantation, while other centers have shown that liver-including allografts have significantly more favorable graft survival and graft loss-due-to chronic rejection (CHR) rates, our center has consistently shown that modified multivisceral (MMV) and full multivisceral (MV) allografts have significantly more favorable acute cellular rejection (ACR) and severe ACR rates compared with isolated intestine (I) and liver-intestine (LI) allografts. In the attempt to resolve this apparent discrepancy, we performed stepwise Cox multivariable analyses of the hazard rates of developing graft loss-due-to acute rejection (AR) vs. CHR among 350 consecutive intestinal transplants at our center with long-term follow-up (median: 13.5 years post-transplant). Observed percentages developing graft loss-due-to AR and CHR were 14.3% (50/350) and 6.6% (23/350), respectively. Only one baseline variable was selected into the Cox model indicating a significantly lower hazard rate of developing graft loss-due-to AR: Transplant Type MMV or MV (p < 0.000001). Conversely, two baseline variables were selected into the Cox model indicating a significantly lower hazard rate of developing graft loss-due-to CHR: Received Donor Liver (LI or MV) (p = 0.002) and Received Induction (p = 0.007). In summary, while MMV/MV transplants (who receive extensive native lymphoid tissue removal) offered protection against graft loss-due-to AR, liver-containing grafts appeared to offer protection against graft loss-due-to CHR, supporting the results of other studies.

Intestinal and Multivisceral Transplantation: Indications and Surgical Techniques

Intestinal transplantation and multivisceral transplantation are technically challenging and complex procedures mainly performed on patients with irreversible and non-medically manageable end-stage intestinal failure. Increasingly, other organs besides small intestines are included in the allograft for which the terms "composite intestinal transplantation" and "multivisceral transplantation" are used. Commonly, complex vascular reconstructions are used for these procedures. Knowledge of surgical anatomy hence is essential for accurate interpretation of postoperative imaging in these patients. This article reviews the indications and most common surgical techniques for intestinal and multivisceral transplantations.

Endoscopy in the Surgically Altered Bowel

Improved utilization of surgical interventions to improve patient outcomes has led to an increased need to endoscopically evaluate and treat the bowel after surgery. The best outcomes are attained when the endoscopist coordinates with the surgeon, and in some cases the pathologist or radiologist to plan the procedure. Understanding the anatomy and pathology anticipated can allow planning for sedation, bowel cleanse and equipment needed. Surgically altered anatomy can create challenges that with planning can be overcome. This article will review how to prepare and navigate several of the most commonly encountered surgical interventions.

Lymphohematopoietic graft-versus-host responses promote mixed chimerism in patients receiving intestinal transplantation

In humans receiving intestinal transplantation (ITx), long-term multilineage blood chimerism often develops. Donor T cell macrochimerism (≥4%) frequently occurs without graft-versus-host disease (GVHD) and is associated with reduced rejection. Here we demonstrate that patients with macrochimerism had high graft-versus-host (GvH) to host-versus-graft (HvG) T cell clonal ratios in their allografts. These GvH clones entered the circulation, where their peak levels were associated with declines in HvG clones early after transplant, suggesting that GvH reactions may contribute to chimerism and control HvG responses without causing GVHD. Consistently, donor-derived T cells, including GvH clones, and CD34+ hematopoietic stem and progenitor cells (HSPCs) were simultaneously detected in the recipients' BM more than 100 days after transplant. Individual GvH clones appeared in ileal mucosa or PBMCs before detection in recipient BM, consistent with an intestinal mucosal origin, where donor GvH-reactive T cells expanded early upon entry of recipient APCs into the graft. These results, combined with cytotoxic single-cell transcriptional profiles of donor T cells in recipient BM, suggest that tissue-resident GvH-reactive donor T cells migrated into the recipient circulation and BM, where they destroyed recipient hematopoietic cells through cytolytic effector functions and promoted engraftment of graft-derived HSPCs that maintain chimerism. These mechanisms suggest an approach to achieving intestinal allograft tolerance.

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.

Utilization of Vicryl Bridging Mesh in Orthotopic Liver Transplantation to Achieve Tension-Free Abdominal Wall Closure: A Case Series

Difficulty in primary fascial closure of the abdomen in transplant patients is a common challenge. Abdominal wall tension may have detrimental effects on the newly transplanted graft due to compression, and blood flow hindrance, potentially leading to ischemia or thrombosis and possibly graft failure. Furthermore, patients will be at risk of developing fascial ischemia and dehiscence. Myocutaneous flaps, temporary closure with silastic mesh, abdominal wall transplants, and even graft reduction, bowel resection, and splenectomies have been practiced with varying degrees of success. In this study, we present four cases of patients who underwent orthotopic liver transplantation (OLT) with bridging Vicryl knitted mesh (ETHICON VKML VICRYL-Polyglactin 910-30 × 30 cm) to relieve the tension during the closure. Our results show that these patients, despite having a high average Model End-Stage Liver Disease (MELD) score of 25, had a good liver function at the time of discharge and continue to upon follow-up. They had a relatively short length of stay (LOS) in both the intensive care unit (ICU) and in the hospital, an average of 3.5 days and 9 days, respectively. Our case series successfully show that utilizing a bridging Vicryl knitted mesh is a reasonable approach to attain tension-free abdominal closure in OLT with satisfying results.

Small bowel transplant: state-of-the-art vascular and nonvascular imaging

BACKGROUND

Small bowel transplant (SBT) is a surgical procedure that may be used in patients with pathology resulting in severe intestinal failure resistant to conventional forms of surgical and nonsurgical treatment. Intestinal failure is defined as the failure of enterocytes to absorb sufficient macronutrients, water, and/or electrolytes to sustain homeostasis and/or promote growth. With the advancement of surgical techniques and advancements in perioperative transplant management, SBT has become an increasingly common treatment for intestinal failure, with survival rates for SBT comparable to those for other solid organ transplants.

MATERIALS AND METHODS

This review provides background on SBT, its variations, and the associated preoperative and postoperative imaging studies with regard to surgical planning and anticipated complications.

RESULTS AND CONCLUSIONS

With the increasing use of SBT, radiologists will be expected to be familiar with the diagnostic studies and available endovascular interventions associated with this procedure.

Association of More Intensive Induction With Less Acute Rejection Following Intestinal Transplantation: Results of 445 Consecutive Cases From a Single Center

BACKGROUND

In intestinal transplantation, acute cellular rejection (ACR) remains a significant challenge to achieving long-term graft survival. It is still not clear which are the most important prognostic factors.

METHODS

We performed a Cox multivariable analysis of the hazard rates of developing any ACR, severe ACR, and cause-specific graft loss during the first 60 months posttransplant among 445 consecutive intestinal transplant recipients at our institution since 1994. Of particular interest was to determine the prognostic influence of induction type: rabbit antithymocyte globulin (rATG; 2 mg/kg × 5)/rituximab (150 mg/m × 1; begun in 2013), alemtuzumab (2001-2011), and less intensive forms.

RESULTS

First ACR and severe ACR occurred in 61.3% (273/445) and 22.2% (99/445) of cases. The following 3 multivariable predictors were associated with significantly lower hazard rates of developing ACR and severe ACR: transplant type modified multivisceral or full multivisceral (P = 0.0009 and P < 0.000001), rATG/rituximab induction (P < 0.000001 and P < 0.01), and alemtuzumab induction (P = 0.004 and P = 0.07). For both ACR and severe ACR, the protective effects of rATG/rituximab and alemtuzumab were highly significant (P ≤ 0.000005 for ACR; P ≤ 0.01 for severe ACR) but only during the first 24 days posttransplant (when the ACR hazard rate was at its peak). The prognostic effects of rATG/rituximab and alemtuzumab on ACR/severe ACR disappeared beyond 24 days posttransplant (ie, nonproportional hazards). While significant protective effects of both rATG/rituximab and alemtuzumab existed during the first 6 months posttransplant for the hazard rate of graft loss-due-to-rejection (P = 0.01 and P = 0.003), rATG/rituximab was additionally associated with a consistently lower hazard rate of graft loss-due-to-infection (P = 0.003). All significant effects remained after controlling for the propensity-to-be-transplanted since 2013.

CONCLUSIONS

More intensive induction was associated with a significant lowering of ACR risk, particularly during the early posttransplant period.

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.

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.

Transplant Critical Care: Is there a Need for Sub-specialized Units? - A Perspective

The critical care involved in solid-organ transplantation (SOT) is complex. Pre-, intra- and post-transplant care can significantly impact both – patients’ ability to undergo SOT and their peri-operative morbidity and mortality. Much of the care necessary for medical optimization of end-stage organ failure (ESOF) patients to qualify and then successfully undergo SOT, and the management of peri-operative and/or long-term complications thereafter occurs in an intensive care unit (ICU) setting. The current literature specific to critical care in abdominal SOT patients was reviewed. This paper provides a contemporary perspective on the potential multifactorial advantages of sub-specialized transplant critical care units in providing efficient, comprehensive, and collaborative multidisciplinary care.

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.

Liver-inclusive intestinal transplantation results in decreased alloimmune-mediated rejection but increased infection

Background and aims

A co-transplanted liver allograft has been thought to protect other organs from rejection-mediated injury; however, detailed analyses of co-transplanted liver on intestinal allograft outcomes have not been conducted to date. The aim of the study was to compare immune-mediated injury, causes of graft failure and clinical outcomes between recipients who underwent either a liver-inclusive intestinal transplant (LITx) or liver-exclusive intestinal transplant (LETx).

Methods

Between May 2000 and May 2010, 212 adult patients undergoing LITx (n =76) and LETx (n =136) were included. LITx underwent either liver combined intestinal or full multivisceral transplantation. LETx underwent either isolated intestinal or modified multivisceral transplantation.

Results

During 44.9 ± 31.4 months of follow-up, death-censored intestinal graft survival was significantly higher for LITx than LETx (96.9%, 93.2% and 89.9% vs 91.4%, 69.3% and 60.0% at 1, 3 and 5 years; p =0.0001). Incidence of graft loss due to rejection was higher in LETx than in LITx (30.9% vs 6.6%; p <0.0001), while infection was the leading cause of graft loss due to patient death in LITx (25.0% vs 5.1%; p <0.0001). Despite similar immunosuppression, the average number (0.87 vs 1.42, p =0.02) and severity of acute cellular rejection episode (severe grade: 7.9% vs 21.3%; p =0.01) were lower in LITx than in LETx. Incidence of acute antibody-mediated rejection was also significantly lower in LITx than in LETx (3.6% vs 15.2%; p =0.03). Incidence of chronic rejection was reduced in LITx (3.9% vs 24.3%; p =0.0002).

Conclusions

Intestinal allografts with a liver component appear to decrease risk of rejection but increase risk of infection. Our findings emphasize that LITx has characteristic immunologic and clinical features. Lower immunosuppression may need to be considered for patients who undergo LITx to attenuate increased risk of infection.

Anesthetic management for intestinal transplantation: A decade of experience

BACKGROUND

Intestinal transplantation (ITx) is the definitive therapy for patients suffering from intestinal failure. Previously published reports suggest that these cases should be managed perioperatively with the same intensive monitors and techniques as in liver transplantation.

METHODS

We retrospectively reviewed the anesthetic management of 67 isolated intestinal, intestinal-pancreas, and intestinal-kidney transplants over the previous decade (2005-2015) in our tertiary care institution.

RESULTS

Patients were typically managed with a single arterial line, a single central venous catheter, and rarely intensive modalities such as a pulmonary artery catheter, a transesophageal echocardiography, a second arterial catheter or central venous catheter, a rapid infusion system, a cell salvage device, or viscoelastic testing. Significant hemodynamic derangements were rare, and the rate of postreperfusion syndrome was 8.96%. Our fluid administration type and volume and transfusion type and volume were similar to previous reports in which more intensive anesthetic management was employed.

CONCLUSION

We demonstrate that ITx can safely occur without utilizing the intensive resources requisite for a liver transplant.

Guidelines for the assessment and acceptance of potential brain-dead organ donors

Organ transplantation is the only alternative for many patients with terminal diseases. The increasing disproportion between the high demand for organ transplants and the low rate of transplants actually performed is worrisome. Some of the causes of this disproportion are errors in the identification of potential organ donors and in the determination of contraindications by the attending staff. Therefore, the aim of the present document is to provide guidelines for intensive care multi-professional staffs for the recognition, assessment and acceptance of potential organ donors.

Ten-Year Experience With Bowel Transplantation at Seoul St. Mary's Hospital

A retrospective review of intestinal transplantation (ITx) at Seoul St. Mary's Hospital was made by collecting clinical data over the past 10 years. Fifteen consecutive cases from 2004 were analyzed. Five children and 10 adults (6 months to 69 years of age) were included. Primary diseases in adults included 4 mesenteric vessel thromboses, 2 strangulations, and 1 each of visceral myopathy, malignant gastrointestinal stromal tumor (GIST), mesenteric lymphangiectasis, and injury. Pediatric cases involved 2 Hirschsprung disease, 2 visceral myopathy, and 1 necrotizing enterocolitis. Three of 7 stomas were closed using a serial transverse enteroplasty procedure before transplantation. The ITx were performed using 3 living-donor Itx, 12 deceased-donor ITx, 14 isolated Itx, and 1 modified multivisceral transplantation. Daclizumab, basiliximab, alemtusumab, or basiliximab with rabbit antithymocyte globulin (rATG) was used for the induction; tacrolimus monotherapy was used as the basic maintenance immunosuppressant; and m-TOR inhibitor was used for renal dysfunction patients. Seven cases of acute cellular rejection were treated with rATG. Three cases of antibody-mediated rejection were treated with rituximab alone or with rituximab and bortezomib combination. There were 4 cases of early mortality within 6 months after Itx. Causes of death were declamping shock, cardiac tamponade with acute cellular rejection, dysmotility, and sepsis. Surgical complications consisted of 1 feeding jejunostomy displacement, and a minor leakage at a colo-colostomy site. One-year survival of the patient and graft was 73.33% (Kaplan-Meier survival curve). Although the total number of ITx is small, its social impact has been remarkable in changing the related laws and reimbursement policy in Korea.

Short Bowel Syndrome: Clinical Guidelines for Nutrition Management

Intestinal failure is a condition in which inadequate digestion or absorption of fluid, electrolytes, and nutrients leads to dehydration or malnutrition. The most common cause of intestinal failure is short bowel syndrome (SBS) defined as <200 cm of functional small intestine. SBS may result from congenital abnormalities or from surgical resection. For the past 3 decades, patients with severe SBS were managed with home parenteral nutrition (HPN). With the emergence of new therapies, the clinician now has multiple options to treat these patients. These include intestinal rehabilitation regimens whereby patients are treated with specialized oral diets, soluble fiber, oral rehydration solutions (ORS), and trophic factors to enhance absorption. There are also a variety of surgical techniques available to preserve intestinal length. Small bowel and multivisceral transplantation has evolved during the last decade to be a valid therapeutic option for those patients who cannot be rehabilitated or who fail HPN. These are interrelated services designed to offer the patient the best therapeutic options to meet their individual needs. This article reviews the principles associated with the nutrition management of this very complex and diverse group of patients.

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.

Intestinal Transplantation in Pediatric Patients

Intestine transplantation has evolved into a feasible alternative for children with permanent intestinal failure and life-threatening complications related to total parenteral nutrition. Although the first transplantations were done nearly 40 years ago, long-term survival has only been achieved in the last decade. Nearly 700 intestinal transplantations have been performed internationally since 1985, with an overall patient survival of greater than 50%. Improvements in patient selection, medical management, and assessment and treatment for rejection and infection have contributed to the increased survival. This article will discuss current results and medical management strategies for this innovative type of transplantation for children with end-stage short gut syndrome.

An Analysis of the Long-Term Complications of Intestine Transplant Recipients

Background

One-year survival rates for intestine transplant recipients have increased to 70%, but it is believed that the complications following the procedure do not diminish after the first year as is seen in other forms of solid-organ transplantation.

Objective

To review the ongoing medical requirements of an increasing number of long-term survivors of intestinal transplantation.

Method

A retrospective medical chart review was completed on all patients who received intestinal transplantation at the University of Nebraska Medical Center from September 1990 through March 2003. One hundred forty-six transplantations were performed on 128 patients—53 intestinal, 70 liver/intestinal, and 23 intestinal with liver and pancreas or kidney.

Results

Seventy-six patients survived longer than 365 days and form the study group. Major reasons for readmissions were infections, gastrointestinal complications, dehydration, and rejection. The average number of rehospitalizations per patient per year remained constant. Death in patients with more than 365 days survival (N=23) was the result of sepsis (56%) and multiple other complications (44%).

Conclusion

The number of readmissions each year per patient remains constant and medical problems remain complex and life threatening. Patients with intestinal transplantation will continue to require regular expert follow-up care and careful attention to even the smallest medical problem even years following transplantation.

Is There a Role for Living Donor Intestine Transplants?

The use of living donors with intestinal transplantation is controversial because it may not significantly improve candidate access to organs when intestine-only grafts are needed, and may involve excessive donor risk when combined liver-intestine grafts are required. Although limited data are available for comparison at this time, graft and patient survival rates for intestinal transplantations using living donors are no different than for deceased donor transplantations. Potential benefits that may be provided to the intestine transplant recipient through the use of living donors include better HLA matching, shorter ischemia times, better bowel preparation, and better opportunities for introducing immunomodulatory strategies. Conversely, living intestine donors are at risk for mortality, significant morbidity, financial loss, and psychologic trauma. The long-term outcomes of living intestine donors have not yet been reported. Ultimately, these data are essential before the wider use of living donors can be advocated for intestinal transplantation.

Immunosuppressant Strategies for Intestinal Transplantation: A Review of a Tolerogenic Regimen

Intestinal, combined liver-intestinal, and multivisceral transplantation are now considered the standard of care for children and adults with permanent intestinal failure. Early attempts at intestinal transplantation were discouraging because of the high incidence of technical complications, rejection, and infection. Advances in the field of transplantation, including the introduction of tacrolimus, improved surgical techniques, and improvements in postoperative care, have led to a renewed interest in intestinal transplantation since 1990. The most significant achievement, however, has been the effective control of rejection and life-threatening infections. This article focuses on the experience to date of innovative strategies that induce lymphocyte depletion and reduction in the incidence of rejection. In this setting, low-maintenance immunosuppression is clinically achievable with an acceptable rate of allograft rejection. Subsequently, the long-term complications of immunosuppression are significantly reduced with achievement of better long-term survival, and an overall improvement in the quality of life.

Decision Making in Intestinal Transplantation

Intestinal transplantation is an accepted lifesaving option to treat appropriately selected patients with end-stage failure of the gastrointestinal tract. The evaluation of each candidate involves complex judgments. When to perform an isolated intestinal transplantation versus a combined transplantation with the liver and/or other organs often requires thoughtful considerations and an individualized approach. In addition, performing venous drainage of the isolated graft is potentially complex. We discuss the significant advances in surgical and medical decision making in the evaluation and management of patients with intestinal failure.

Cholestasis in Preterm Infants

Cholestasis in preterm infants has a multifactorial etiology. Risk factors include degree of prematurity, lack of enteral feeding, intestinal injury, prolonged use of parenteral nutrition (PN), and sepsis. Soy-based parenteral lipid emulsions have been implicated in the pathophysiology of PN-associated liver injury. Inflammation plays an important role. Medical therapies are used; however, their effects have not consistently proven effective. Evaluation of cholestasis involves laboratory work; direct bilirubin levels are used for diagnosis and trending. Adverse outcomes include risk for hepatobiliary dysfunction, irreversible liver failure, and death. Early enteral feedings as tolerated is the best way to prevent and manage cholestasis.

Intestinal Failure: Adaptation, Rehabilitation, and Transplantation

Intestinal failure (IF) is a state in which the nutritional demands are not met by the gastrointestinal absorptive surface. A majority of IF cases are associated with short-bowel syndrome, which is a result of malabsorption after significant intestinal resection for numerous reasons, some of which include Crohn's disease, vascular thrombosis, and radiation enteritis. IF can also be caused by obstruction, dysmotility, and congenital defects. Recognition and management of IF can be challenging, given the complex nature of this condition. This review discusses the management of IF with a focus on intestinal rehabilitation, parenteral nutrition, and transplantation.

Difficulties, guidelines and review of developing an acute rejection model after rat intestinal transplantation

Experimental small bowel transplantation (SBT) in rats has been proven to be a useful tool for the study of ischemia-reperfusion and immunological aspects related to solid organ transplantation. However, the model is not completely refined, specialized literature is scarce and complex technical details are typically omitted or confusing. Most studies related to acute rejection (AR) use the orthotopic standard, with small sample sizes due to its high mortality, whereas those studying chronic rejection (CR) use the heterotopic standard, which allows longer term survival but does not exactly reflect the human clinical scenario. Various animal strains have been used, and the type of rejection and the timing of its analysis differ among authors. The double purpose of this study was to develop an improved unusual AR model of SBT using the heterotopic technique, and to elaborate a guide useful to implement experimental models for studying AR. We analyzed the model's technical details and expected difficulties in overcoming the learning curve for such a complex microsurgical model, identifying the potential problem areas and providing a step-by-step protocol and reference guide for future surgeons interested in the topic. We also discuss the historic and more recent options in the literature.

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 transplantation: The anesthesia perspective

Intestinal transplantation is a complex and challenging surgery. It is very effective for treating intestinal failure, especially for those patients who cannot tolerate parenteral nutrition nor have extensive abdominal disease. Chronic parental nutrition can induce intestinal failure associated liver disease (IFALD). According to United Network for Organ Sharing (UNOS) data, children with intestinal failure affected by liver disease secondary to parenteral nutrition have the highest mortality on a waiting list when compared with all candidates for solid organ transplantation. Intestinal transplant grafts can be isolated or combined with the liver/duodenum/pancreas. Organ Procurement and Transplantation Network (OPTN) has defined intestinal donor criteria. Living donor intestinal transplant (LDIT) has the advantages of optimal timing, short ischemia time and good human leukocyte antigen matching contributing to lower postoperative complications in the recipient. Thoracic epidurals provide excellent analgesia for the donors, as well as recipients. Recipient management can be challenging. Thrombosis and obstruction of venous access maybe common due to prolonged parenteral nutrition and/or hypercoaguability. Thromboelastography (TEG) is helpful for managing intraoperative product therapy or thrombosis. Large fluid shifts and electrolyte disturbances may occur due to massive blood loss, dehydration, third spacing etc. Intestinal grafts are susceptible to warm and cold ischemia and ischemia-reperfusion injury (IRI). Post-reperfusion syndrome is common. Cardiac or pulmonary clots can be monitored with transesophageal echocardiography (TEE) and treated with recombinant tissue plasminogen activator. Vasopressors maybe used to ensure stable hemodynamics. Post-intestinal transplant patients may need anesthesia for procedures such as biopsies for surveillance of rejection, bronchoscopy, endoscopy, postoperative hemorrhage, anastomotic leaks, thrombosis of grafts etc. Asepsis, drug interactions between anesthetic and immunosuppressive agents and venous access are some of the anesthetic considerations for this group.

Long-term endoscopic follow-up in small bowel transplant recipients: single-center series

BACKGROUND

The reliability of endoscopic findings after adult intestinal transplantation on short-term follow-up has been shown. The aim of this study was to evaluate in a long-term follow-up the diagnostic value of endoscopies compared with the biopsy value.

METHODS

We evaluated 52 endoscopies over a period of 2 years (2 in each patient in 2010 and 1 in each patient in 2011, plus 1 endoscopy for suspected post-transplant lymphoproliferative disease [PTLD]) on 17 recipients transplanted between the years 2000 and 2006 (more than 5 years of follow-up).

RESULTS

All the 52 endoscopic findings were comparable to biopsy definitive results: only 1 case of mild enteritis and 1 case of Epstein-Barr virus (EBV) chronic infection at biopsy were not diagnosed by endoscopy. One case of rectal PTLD and 1 of EBV-related enteritis were diagnosed by use of both procedures. Specificity was 98%: we did not calculate sensitivity because no episodes of rejection were diagnosed because recipients were stable in long-term follow-up.

CONCLUSIONS

Endoscopy is a reliable procedure even on a long-term follow-up after intestinal transplantation, allowing a support to biopsy for diagnosis on adult recipients, especially for EBV infections and PTLD surveillance.

Protein-engineered scaffolds for in vitro 3D culture of primary adult intestinal organoids

Though in vitro culture of primary intestinal organoids has gained significant momentum in recent years, little has been done to investigate the impact of microenvironmental cues provided by the encapsulating matrix on the growth and development of these fragile cultures. In this work, the impact of various in vitro culture parameters on primary adult murine organoid formation and growth are analyzed with a focus on matrix properties and geometric culture configuration. The air-liquid interface culture configuration was found to result in enhanced organoid formation relative to a traditional submerged configuration. Additionally, through use of a recombinantly engineered extracellular matrix (eECM), the effects of biochemical and biomechanical cues were independently studied. Decreasing mechanical stiffness and increasing cell adhesivity were found to increase organoid yield. Tuning of eECM properties was used to obtain organoid formation efficiency values identical to those observed in naturally harvested collagen I matrices but within a stiffer construct with improved ease of physical manipulation. Increased ability to remodel the surrounding matrix through mechanical or enzymatic means was also shown to enhance organoid formation. As the engineering and tunability of recombinant matrices is essentially limitless, continued property optimization may result in further improved matrix performance and may help to identify additional microenvironmental cues that directly impact organoid formation, development, differentiation, and functional behavior. Continued culture of primary organoids in recombinant matrices could therefore prove to be largely advantageous in the field of intestinal tissue engineering for applications in regenerative medicine and in vitro tissue mimics.

The concept of gut rehabilitation and the future of visceral transplantation

In the 1990s, the introduction of visceral transplantation fuelled interest in other innovative therapeutic modalities for gut rehabilitation. Ethanol lock and omega-3 lipid formulations were introduced to reduce the risks associated with total parenteral nutrition (TPN). Autologous surgical reconstruction and bowel lengthening have been increasingly utilized for patients with complex abdominal pathology and short-bowel syndrome. Glucagon-like peptide 2 analogue, along with growth hormone, are available to enhance gut adaptation and achieve nutritional autonomy. Intestinal transplantation continues to be limited to a rescue therapy for patients with TPN failure. Nonetheless, survival outcomes have substantially improved with advances in surgical techniques, immunosuppressive strategies and postoperative management. Furthermore, both nutritional autonomy and quality of life can be restored for more than two decades in most survivors, with social support and inclusion of the liver being favourable predictors of long-term outcome. One of the current challenges is the discovery of biomarkers to diagnose early rejection and further improve liver-free allograft survival. Currently, chronic rejection with persistence of preformed and development of de novo donor-specific antibodies is a major barrier to long-term graft function; this issue might be overcome with innovative immunological and tolerogenic strategies. This Review discusses advances in the field of gut rehabilitation, including intestinal transplantation, and highlights future challenges. With the growing interest in individualized medicine and the value of health care, a novel management algorithm is proposed to optimize patient care through an integrated multidisciplinary team approach.

Intestinal transplant registry report: global activity and trends

The Registry has gathered information on intestine transplantation (IT) since 1985. During this time, individual centers have reported progress but small case volumes potentially limit the generalizability of this information. The present study was undertaken to examine recent global IT activity. Activity was assessed with descriptive statistics, Kaplan-Meier survival curves and a multiple variable analysis. Eighty-two programs reported 2887 transplants in 2699 patients. Regional practices and outcomes are now similar worldwide. Current actuarial patient survival rates are 76%, 56% and 43% at 1, 5 and 10 years, respectively. Rates of graft loss beyond 1 year have not improved. Grafts that included a colon segment had better function. Waiting at home for IT, the use of induction immune-suppression therapy, inclusion of a liver component and maintenance therapy with rapamycin were associated with better graft survival. Outcomes of IT have modestly improved over the past decade. Case volumes have recently declined. Identifying the root reasons for late graft loss is difficult due to the low case volumes at most centers. The high participation rate in the Registry provides unique opportunities to study these issues.

Engineering of three-dimensional microenvironments to promote contractile behavior in primary intestinal organoids

Multiple culture techniques now exist for the long-term maintenance of neonatal primary murine intestinal organoids in vitro; however, the achievement of contractile behavior within cultured organoids has thus far been infrequent and unpredictable. Here we combine finite element simulation of oxygen transport and quantitative comparative analysis of cellular microenvironments to elucidate the critical variables that promote reproducible intestinal organoid contraction. Experimentally, oxygen distribution was manipulated by adjusting the ambient oxygen concentration along with the use of semi-permeable membranes to enhance transport. The culture microenvironment was further tailored through variation of collagen type-I matrix density, addition of exogenous R-spondin1, and specification of culture geometry. "Air-liquid interface" cultures resulted in significantly higher numbers of contractile cultures relative to traditional submerged cultures. These interface cultures were confirmed to have enhanced and more symmetric oxygen transport relative to traditional submerged cultures. While oxygen availability was found to impact in vitro contraction rate and the orientation of contractile movement, it was not a key factor in enabling contractility. For all conditions tested, reproducible contractile behavior only occurred within a consistent and narrow range of collagen type-I matrix densities with porosities of approximately 20% and storage moduli near 30 Pa. This suggests that matrix density acts as a "permissive switch" that enables contractions to occur. Similarly, contractions were only observed in cultures with diameters less than 15.5 mm that had relatively large interfacial surface area between the compliant matrix and the rigid culture dish. Taken together, these data suggest that spatial geometry and mechanics of the microenvironment, which includes both the encapsulating matrix as well as the surrounding culture device, may be key determinants of intestinal organoid functionality. As peristaltic contractility is a crucial requirement for normal digestive tract function, this achievement of reproducible organoid contraction marks a pivotal advancement towards engineering physiologically functional replacement tissue constructs.

Multivisceral transplantation: where do we stand?

Intestinal transplantation is the definitive therapy for patients with irreversible intestinal failure and can be combined with transplantation of other abdominal organs, such as stomach, spleen, and pancreas with or without liver. There is an increasing trend in the volume of intestinal and multivisceral transplantation in the past few decades and there is also increasing trend in patient and graft survival primarily due to improved patient selection, advances in immunosuppression, and improved perioperative management. This review summarizes the various key elements in patient selection, types of grafts, and updates in the perioperative management involved in multivisceral transplantation.

Intestinal transplantation: review of operative techniques

The improvement of outcomes in intestinal transplantation (ITx) over the last two decades has been made possible through standardization in surgical techniques, improvements in immunosuppressive and induction protocols, and post-operative patient care. From a surgical technical point of view, all different types of small bowel containing transplants can be categorized into three main prototypes, including isolated small bowel, liver-small bowel, and multivisceral transplantations. In this review, we describe these three main prototypes and discuss the most important technical modifications of each type, as well as donor and recipient procedures, and highlight the more recent operative technical topics of discussion in the literature.

India's first successful intestinal transplant: the road traveled and the lessons learnt

Intestinal transplant is a therapeutic challenge not just surgically but also logistically because of the multidisciplinary expertise and resources required. A large proportion of patients who undergo massive bowel resection and develop intestinal failure have poor outcome, because of inability to sustain long-term parenteral nutrition and limited availability of intestinal and multi-visceral transplantation facilities. We report the first successful isolated intestinal transplant from India.

Hypoxia enhances protective effect of placental-derived mesenchymal stem cells on damaged intestinal epithelial cells by promoting secretion of insulin-like growth factor-1

Apoptosis and necrosis of intestinal epithelial cells (IECs), induced by ischemia-reperfusion (I/R) injury, can lead to dysfunction of the intestinal barrier, which could cause multiple organ dysfunction syndromes. Mesenchymal stem cells (MSCs) have the potential of providing protective effects on damaged IECs via paracrine action. This study investigated whether hypoxia can enhance the protective effect of placental-derived MSCs (pMSCs) on H2O2-treated-caco2 cells, and explored the possible mechanism. The pMSCs isolated by tissue culture were fibroblast-like, positive for CD73, CD90 and CD105 and can differentiate into chondrocytes and endothelial cells. Five days after treatment with H2O2, the numbers of living caco2 cells significantly decreased. More live H2O2-treated-caco2 cells were observed in pMSCs hypoxia culture medium (pMSCs-HCM) than pMSCs normoxia culture medium (pMSCs-NCM), and the application of a specific antibody that blocked insulin-like growth factor-1 (IGF-1) leads to a significant decrease of the protective effect of pMSCs-HCM. Hypoxia can promote IGF-1 expression of pMSCs at mRNA and protein levels, and caco2 stably expressed IGF-1 receptor. Knocking down IGF-1 expression in pMSCs by siRNA resulted in a significant attenuation of the increase in apoptosis of H2O2-treated-caco2 cultured in pMSCs-HCM. In conclusion, hypoxia can increase the protective effect of pMSCs on H2O2-treated-caco2 cells via a promotion of their paracrine actions, and the key cytokine involved is IGF-1.