Indications for Intestinal Transplantation.

Outcomes for patients with chronic intestinal failure have improved with organization of experts into multidisciplinary teams delivering care in intestinal rehabilitation programs. There have been improvements in understanding of intestinal failure complications as well as development of newer therapies that have amplified the improvements in survival. In spite of this encouraging trend, patients who fail PN are often referred too late for intestinal transplantation. The author proposes a more rational framework that might allow earlier identification of intestinal failure patients at risk for PN-failure, who could appropriately be considered earlier for intestinal transplantation with improvements in overall outcomes.

Risk factors for renal dysfunction after isolated intestinal transplantation.

INTRODUCTION: Kidney dysfunction is a known complication of intestinal transplantation; however, the rate of development and risk factors for chronic kidney disease (CKD) remain poorly defined. METHODS: This was a single-center retrospective review of isolated adult intestinal allograft recipients from 2011 to 2019. Patients who died or experienced graft loss within 1-year or had a prior transplant were excluded. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation at 0-, 6- and 12-months post-transplant, and multivariable linear regression was performed to identify variables associated with adjusted eGFR at 1-year. Independent variables included age, ethnicity, BMI, history of diabetes/hypertension, vasopressor use, TPN and stoma days, urinary or bloodstream infections, intravenous contrast exposure, rejection, concomitant immunosuppression, and time above the therapeutic range of tacrolimus. Variables with a p < .1 in univariate analysis were considered for multivariable modeling. RESULTS: Thirty-three patients were included with a mean age of 43.9 ± 13.0. A mean 42.3% decline in eGFR was observed at 1-year post-transplant, with 15.2% of patients developing new stage 4/5 CKD. Factors associated with a greater decline in adjusted eGFR in the univariate model included increasing age, decreased BMI, stoma days, and vasopressor use. In the adjusted multivariable model patient age (ß = -.77, p < .01) and stoma days (ß = -.06, p < .01) remained significant. Tacrolimus and sirolimus exposure were not associated with decline in eGFR at 1 year. CONCLUSIONS: Renal dysfunction is common following intestinal transplantation. The need for stoma creation should be carefully considered, and reversal should be performed when feasible for renal protection.

Knowledge of chronic intestinal failure among US gastroenterologists: Cause for concern and learning opportunity.

BACKGROUND: Chronic intestinal failure (CIF) is an ultrarare disease, with an estimated national prevalence of ∼25,000 cases. There is a suspicion of widespread lack of expertise in CIF care, but no formal assessment tool or data exist. We developed and validated a knowledge test in CIF and now report our preliminary results from testing CIF knowledge in a cohort of US gastroenterologists. METHOD: We developed a 20-question knowledge test in CIF, covering four key components of IF. After internal testing, refinement, and revision, we administered the test to a convenience sample of experts and nonexperts in IF. We then deployed the validated test to a cohort of 100 US gastroenterologists. RESULTS: The test had a Cronbach alpha of 0.74, suggesting a reliable test, with a threshold score to discriminate experts and nonexperts of 13.4 (maximum 20) and with a sensitivity of 81.3% and specificity of 86.4%. The overall mean score of 8.2 for the 100 US gastroenterologists was at the level of nonexperts in our convenience sample. CONCLUSION: The preliminary results of our validated knowledge test in IF among a broad group of US gastroenterologists demonstrate lack of knowledge in IF.

Impact of the acuity circle model for liver allocation on multivisceral transplant candidates.

Liver allocation was updated on February 4, 2020, replacing a Donor Service Area (DSA) with acuity circles (AC). The impact on waitlist outcomes for patients listed for combined liver-intestine transplantation (multivisceral transplantation [MVT]) remains unknown. The Organ Procurement and Transplantation Network/United Network for Organ Sharing database was used to identify all candidates listed for both liver and intestine between January 1, 2018 and March 5, 2021. Two eras were defined: pre-AC (2018-2020) and post-AC (2020-2021). Outcomes included 90-day waitlist mortality and transplant probability. A total of 127 adult and 104 pediatric MVT listings were identified. In adults, the 90-day waitlist mortality was not statistically significantly different, but transplant probability was lower post-AC. After risk-adjustment, post-AC was associated with a higher albeit not statistically significantly different mortality hazard (sub-distribution hazard ratio[sHR]: 8.45, 95% CI: 0.96-74.05; p = .054), but a significantly lower transplant probability (sHR: 0.33, 95% CI: 0.15-0.75; p = .008). For pediatric patients, waitlist mortality and transplant probability were similar between eras. The proportion of patients who underwent transplant with exception points was lower post-AC both in adult (44% to 9%; p = .04) and pediatric recipients (65% to 15%; p = .002). A lower transplant probability observed in adults listed for MVT may ultimately result in increased waitlist mortality. Efforts should be taken to ensure equitable organ allocation in this vulnerable patient population.

Tacrolimus time-in-therapeutic range is associated with freedom from acute rejection and graft failure following intestinal transplantation.

BACKGROUND: Trough-adjusted tacrolimus is commonly prescribed following intestinal transplantation to prevent allograft rejection. Despite established practice, there remains limited direct evidence linking tacrolimus levels with improved clinical outcomes. METHODS: This was a single-center review of all adult non-liver containing intestinal allograft recipients from 2011 to 2018. Patients received lymphocyte depleting induction and maintenance immunosuppression consisting of tacrolimus and a corticosteroid taper. Tacrolimus time-in-therapeutic range (TAC-TTR) was calculated for all patients from the date of transplant until 1-year post-transplant using Rosendaal's method. Cox-Proportional hazards modeling was utilized to assess freedom from acute rejection and graft failure stratified by TAC-TTR quartile. RESULTS: 47 patients were included in the review. Mean TAC-TTR for the cohort was 30.2% ± 11.4. Fifteen episodes of acute rejection were observed, 8 of which were severe. Patients in the highest TAC-TTR quartile >36% had a lower incidence of acute rejection and graft failure relative to patients with a TAC-TTR <20%. Cox-Proportional hazards modeling found a 10% decrease in TAC-TTR was associated with an increased hazard for acute rejection (2.03), severe acute rejection (2.19), and graft loss (3.33). CONCLUSION: The results of this study suggest that decreasing TAC-TTR is a risk factor for both acute rejection as well as intestinal allograft failure.

Enhanced virtual crossmatch in intestinal transplantation: association with outcomes and application in practice.

Background: The presence of preformed donor-specific antibodies in recipient serum against anti-human leukocyte antigen is a significant risk factor that negatively affects the outcomes of intestinal transplantation. Avoiding high-risk intestinal transplantation by physical and virtual cross matches has had limited success due to time constraints and ineffective correlation, respectively. Methods: We developed a guideline to improve the association between physical and virtual cross matches using the retrospective data of 56 consecutive primary adult isolated intestinal transplantations from a single center. Results: The mean fluorescence intensity of 2,000 for positive donor-specific antibodies revealed the best association between physical and virtual cross matches among different cut-off values, but with an unacceptable false positive rate of 54%. An enhanced virtual cross match with the summation of the mean fluorescence intensity of each anti-human leukocyte antigen improved the association between physical and virtual cross matches, with a sensitivity of 83% and specificity of 98%. Conclusions: This enhanced virtual cross match more effectively predicts high-risk intestinal transplantation and is a better substitute for physical cross-match than the current virtual cross match. It also helps to avoid ill-considered abandonment of intestinal transplantation that is unnecessarily deemed high risk based on a simple virtual cross match.

"Stoma or no stoma": First report of intestinal transplantation without stoma.

Recent data suggest that frequent endoscopy and biopsy without evidence of graft dysfunction does not appear to confer survival advantage after intestinal transplantation. After abandoning protocol surveillance, endoscopic examination was decreased significantly at our center. These observations led us to question the need for stoma creation in intestinal transplantation. Herein, we report clinical outcomes of intestinal transplantation without stoma, compared to conventional transplant with stoma. Data analysis was limited to adult intestinal transplantation without liver allograft between 2015 and 2018. We compared patient and graft survival, frequency of endoscopic evaluation, episodes of acute rejection, nutritional therapy, and renal function between "Control group (with stoma)," n = 18 grafts in 16 patients and "Study group (without stoma)," n = 16 grafts in 15 patients. Overall outcome was similar between the 2 groups with respect to graft and patient survival, episodes of acute rejection, and its response to treatment. Nutritional outcomes were similar in both groups. Fewer antidiarrheal medications were required in the study group, but this did not translate into demonstrable gains in preservation of renal function, despite an apparent trend to improvement. Intestinal transplantation without stoma appears to be an acceptable practice model without obvious adverse impact on outcome.

Teduglutide for the treatment of adults with intestinal failure associated with short bowel syndrome: pooled safety data from four clinical trials.

BACKGROUND: In multiple clinical studies, teduglutide reduced parenteral support (PS) with a consistent safety profile in adults with short bowel syndrome-associated intestinal failure (SBS-IF). The objective of this study was to assess adverse events (AEs) from a pooled data set. METHODS: Safety data from four prospective clinical trials of teduglutide in patients with SBS-IF were assimilated. AEs were evaluated in patient groups based on treatment received in each study and in populations stratified to create distinct subgroups based on aetiology, bowel anatomy and baseline PS volume requirements. RESULTS: Safety data are reported for up to 2.5 years, totalling 222 person-years exposure to teduglutide. In most patients, AEs were reported as mild or moderate in severity in all patient groups and occurred at comparable rates between patients who received teduglutide or placebo. Several common gastrointestinal AEs, including abdominal pain, nausea and abdominal distension, were reported more frequently earlier in the course of treatment, with their frequency declining over time. Fewer gastrointestinal AEs were reported in patients with vascular causes of SBS-IF and patients with most of their colon-in-continuity than in other patient subgroups. Across the patient stratification subgroups, the predominant treatment-emergent AEs for which patients receiving teduglutide had a significantly increased relative risk were abdominal distension and gastrointestinal stoma complication compared with patients receiving placebo. CONCLUSIONS: Teduglutide had a safety profile consistent with prior adult data and no new safety concerns were identified. The most frequently reported AEs were gastrointestinal in origin, consistent with the underlying disease condition and intestinotrophic actions of teduglutide. CLINICAL TRIAL REGISTRY INFORMATION: NCT00081458/EudraCT, 2004-000438-35; NCT00798967/EudraCT, 2008-006193-15; NCT00172185/EudraCT, 2004-000439-27; NCT00930644/EudraCT, 2009-011679-65.

Routine surveillance endoscopy and biopsy after isolated intestinal transplantation-Revisiting the gold standard.

The value of endoscopy and biopsy after intestinal transplantation in the absence of clinical concerns has never been investigated. We examined clinical yield of routine surveillance endoscopy and biopsy (control group, n = 28, Jan 2011 to Jun 2014). Most episodes of acute rejection were diagnosed when there were clinical symptoms or signs such as increased stoma output, fever, or bacteremia, but not by routine surveillance endoscopy and biopsy. The new protocol abandoned routine surveillance. Intestinal allografts were examined only when relevant clinical symptoms and/or signs raised concern for graft dysfunction. We compared outcomes between control and study groups (new protocol, n = 25, Jul 2014 to Dec 2016). Incidence of acute rejection (32% vs 32%), graft salvage rate after acute rejection treatment (78% vs 63%), patient survival (75% vs 88% 1 year, 71% vs 83% 3 years after intestinal transplantation), and graft survival (68% vs 80% 1 year, 61% vs 76% 3 years after intestinal transplantation) were similar between control and study groups. Protocol-driven, routine surveillance endoscopy, and biopsy do not appear to confer any survival advantage to patients or grafts. Endoscopy and biopsy "for cause" without routine surveillance seem to be effective and adequate to monitor intestinal allografts.

Is There a Role for Desensitization in Intestinal Transplantation?

Human leukocyte antigen allosensitization prior to transplant can increase the risk of early graft loss and prolong waitlist times for intestinal transplant candidates. Desensitization offers a potential therapeutic option to reduce the quantity of preformed antibodies prior to organ allocation and facilitate transplantation with a more immunologically compatible donor allograft. However, there remains a paucity of data to guide the use of desensitization in the setting of intestinal transplantation. As a result, in this review we evaluate the existing literature supporting the role of desensitization therapy in intestinal transplant, describe our own experience with the implementation of a risk-stratified desensitization protocol, and finally explore barriers and unanswered questions that continue to limit the widespread adoption of desensitization as a management strategy for highly sensitized intestinal transplant candidates.

Single-Center Experience with the Use of Teduglutide in Adult Patients with Short Bowel Syndrome.

BACKGROUND: Teduglutide is a glucagon-like peptide 2 (GLP-2) analog that has been approved for the treatment of adult short bowel syndrome (SBS)-associated intestinal failure (IF; SBS-IF). Teduglutide increases villus height and crypt depth in the small bowel mucosa, promoting nutrition absorption and enteral independence from parenteral nutrition (PN). We aim to report our single-center experience with teduglutide in adult patients with SBS to provide real-world context to its use. METHOD: We conducted a retrospective analysis on patients managed within our tertiary-level intestinal rehabilitation program to identify patients with SBS-IF treated with teduglutide from 2009-2015. The current report includes all patients at our center who had any exposure to teduglutide, including those who received commercial drug after approval by the Food and Drug Administration (FDA) and outside the scope of clinical trials. RESULTS: A total of 18 patients were treated with teduglutide. Eleven patients (61%) achieved complete enteral independence from PN and/or intravenous fluids (IV) at a median time of 10 months (range: 3-36 months). PN/IV volume requirement was reduced in all patients except two. Ten of the 11 patients (91%) who achieved enteral autonomy had colon. All patients off PN/IV required additional oral vitamins and electrolyte supplementations. CONCLUSION: Our preliminary experience is consistent with prior reports of successful partial or complete weaning from PN/IV with teduglutide treatment in adult patients with SBS. The presence of colon appears to be favorable in obtaining enteral independence from PN/IV, regardless of residual small bowel length. Patients on teduglutide may remain at high risk of micronutrient deficiencies.

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

BACKGROUND: The ideal donor in intestinal transplantation (ITX) is generally considered to be 50% to 70% of recipient body weight. This may be due to concerns for "small for size" syndrome as seen in liver transplantation. We report our experience using smaller donors (donor-recipient weight ratio [DRWR], < 50%) in ITX recipients. METHODS: We studied a group of ITX recipients with DRWR of 50% or less to unmatched controls who received intestinal allografts with DRWR greater than 50%. We examined patient and graft survival and enteral autonomy from parenteral nutrition as surrogate markers for safety of using smaller donors and ease of abdominal wall closure between groups to determine the value. RESULTS: There was no difference in overall patient and graft survival, time to enteral autonomy from parenteral nutrition, and weight gain after ITX over time between groups. The need for complicated abdominal closure techniques was significantly more frequent in the control group than in the study group (34.6% vs 6.9%, P = 0.01). Secondary abdominal closure occurred more frequently in the control group (15.4% vs 0%, P = 0.014). Wound revisions also occurred more frequently in the control group (15.4% vs 0%, P = 0.028). CONCLUSIONS: Our data suggest that ITX using smaller donors (DRWR ≤ 50%) seems to be an acceptable practice without adverse impact on surgical complications, nutritional autonomy, and patient and graft survival. Abdominal wall closure seems easier in recipients of smaller donors and "small for size" syndrome as described in liver transplantation does not occur with intestinal allografts.

Deceased Donor Organ Transplantation Performed in the United States for Noncitizens and Nonresidents.

Since 2012, the Organ Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing (UNOS) has required transplant centers to record the citizenship residency status of patients undergoing transplantation in the United States. This policy replaced the 5% threshold of the non-US citizen/nonresidents (NC/NR) undergoing organ transplantation that could result in an audit of transplant center activity. Since April 1, 2015, the country of residence for the NC/NR on the waitlist has also been recorded. We analyzed the frequency of NC/NR deceased donor organ transplants and waitlist registrations at all US transplant centers by data provided by UNOS for that purpose to the UNOS Ad Hoc International Relations Committee. During the period of 2013 to 2016, 1176 deceased donor transplants (of all organs) were performed in non-US citizen/non-US resident (NC/NR) candidates (0.54% of the total number of transplants). We focused on high-volume NC/NR transplant centers that performed more than 5% of the deceased donor kidney or liver transplants in NC/NR or whose waitlist registrants exceeded 5% NC/NR. This report was prepared to fulfill the transparency policy of UNOS to assure a public trust in the distribution of organs. When viewed with a public awareness of deceased donor organ shortages, it suggests the need for a more comprehensive understanding of current NC/NR activity in the United States. Patterns of organ specific NC/NR registrations and transplantations at high-volume centers should prompt a review of transplant center practices to determine whether the deceased donor and center resources may be compromised for their US patients.

Pre-emptive Intestinal Transplant: The Surgeon's Point of View.

Pre-emptive transplantation is a well-established practice for certain types of end-organ failure such as in the use of kidney transplantation. For irreversible intestinal failure, total parenteral nutrition (TPN) remains the gold standard, due to the suboptimal long-term results of intestinal transplantation. As such, the only role for pre-emptive transplantation, if at all, will be for patients identified to be at high risk of complications and mortality while on definitive long-term TPN. In these patients, the timing of early listing and transplantation could become life-saving, taking into account that mortality on the waiting list is still the highest for intestinal candidates. The development of simulation models or pre-transplant scoring systems could help in selecting patients based on potential outcome on TPN or with transplantation, and recent reports from high-volume centers identify few underlying pathologic conditions and some TPN complications as at higher risk of increased morbidity and mortality. A pre-emptive transplant could be used as a rehabilitative procedure in a well-selected case-by-case scenario, among TPN patients at risk of liver failure, repeated central line infections, mesenteric infarction, short bowel syndrome (SBS) <50 cm or with end stoma, congenital mucosal disease, desmoid tumors: These conditions must be carefully evaluated, not to underestimate the clinical stage nor to over-estimate the impact of a temporary situation. At the present time, diseases with a variable and unpredictable course, such as intestinal dysmotility disorders, or quality of life and financial issues are still far from being considered as indications for a pre-emptive transplant.

Independence From Parenteral Nutrition and Intravenous Fluid Support During Treatment With Teduglutide Among Patients With Intestinal Failure Associated With Short Bowel Syndrome.

BACKGROUND: In phase III clinical studies, treatment with teduglutide was associated with clinically meaningful reductions (≥20% from baseline) in parenteral support (PS; parenteral nutrition and/or intravenous fluids) requirements in adult patients with intestinal failure associated with short bowel syndrome (SBS-IF). This analysis reports clinical characteristics of patients who achieved complete independence from PS during teduglutide treatment. MATERIALS AND METHODS: Post hoc analysis of adult patients who achieved complete PS independence during treatment with teduglutide 0.05 mg/kg/d. Data were pooled from 5 teduglutide clinical trials (2 phase III placebo-controlled trials [NCT00081458 and NCT00798967] and their respective extension studies [NCT00172185, NCT00930644, NCT01560403]). Descriptive statistics were used; no between-group comparisons were performed because of the small sample size and lack of comparator. RESULTS: Of 134 patients, 16 gained oral or enteral autonomy after a median of 5 years of PS dependence and 89 weeks of teduglutide treatment. Demographic and baseline disease characteristics varied among patients (median age, 55 years; 50% men; median baseline PS volume, 5.1 L/wk; median residual small intestine length, 52.5 cm). Most patients who achieved PS independence had colon-in-continuity; however, there was no significant difference in the frequency of PS independence among patients who maintained colon-in-continuity vs those who did not. CONCLUSION: Findings from this post hoc analysis suggest that oral or enteral autonomy is possible for some patients with SBS-IF who are treated with teduglutide, regardless of baseline characteristics and despite long-term PS dependence.

Surgical management of short bowel syndrome.

For patients with short bowel syndrome (SBS), surgery can play an important role in preventing, mitigating, and, in some cases, reversing intestinal failure (IF). During intestinal resection, bowel length should be conserved to the fullest extent possible to avoid dependence on parenteral nutrition (PN). Bowel salvage may be improved by initially preserving tissue of questionable viability and later reevaluating during "second-look" procedures. Once the patient is stabilized, ostomy reversal and recruitment of distal unused bowel should be prioritized whenever feasible. Following progression to IF, surgical management of SBS depends on the symptoms and anatomical characteristics of the individual patient. For carefully selected patients with rapid intestinal transit and dilated bowel, longitudinal intestinal lengthening and tailoring (LILT) and serial transverse enteroplasty (STEP) procedures may provide benefit. Outcomes following STEP and LILT are generally similar, and the choice between these procedures may rest on surgeon preference. For patients with rapid intestinal transit in the absence of bowel dilation, segmental reversal of the small bowel may reduce PN requirements. Intestinal transplantation is the standard of care for patients in whom intestinal rehabilitation attempts have failed and who are at risk of life-threatening complications of PN. Because patients awaiting isolated intestine transplant show increased survival compared with patients awaiting combined intestine-liver transplant, early referral of appropriate patients, before the development of advanced liver disease, is critical to enhancing patient outcomes.

Cholangiolocellular carcinoma in a pediatric patient with small duct sclerosing cholangitis: a case report.

Although guidelines exist for routine screening for malignancy in adults with primary sclerosing cholangitis, no imaging guidelines exist for the pediatric population. Cholangiolocellular carcinoma is a rare malignant liver tumor that has been found in adults with chronic liver disease. We present a case of cholangiolocarcinoma found in an adolescent boy with small duct sclerosing cholangitis. The diagnosis of small duct sclerosing cholangitis was made at the age of 6 at which time he also had advanced fibrosis histologically, but no evidence of decompensation either clinically or biochemically. Several years after this diagnosis, a small liver lesion was found incidentally on computed tomography scan following a motorcycle accident. This lesion was shown to be stable by magnetic resonance imaging over the course of 2 years. At 15 years of age, magnetic resonance imaging findings changed with features suggestive of malignancy. This led to resection of the lesion. Pathologic examination confirmed the presence of cholangiolocarcinoma, a tumor found primarily in adults with a history of viral hepatitis. To our knowledge, this is the first such report in a pediatric patient.

Benign liver masses and lesions in children: 53 cases over 12 years.

BACKGROUND: Primary liver masses in children may require intervention because of symptoms or concern about malignant transformation. OBJECTIVES: To review the management and outcome of benign liver masses in children. METHODS: We conducted a retrospective chart review of children with liver masses referred to our institution during the period 1997-2009. RESULTS: Benign liver masses were identified in 53 children. Sixteen of these children (30%) had hemangioma/infantile hepatic hemangioendothelioma (IHH) and 15 (28%) had focal nodular hyperplasia. The remainder had 6 cysts, 4 hamartomas, 3 nodular regenerative hyperplasia, 2 adenomas, 2 vascular malformations, and one each of polyarteritis nodosa, granuloma, hepatic hematoma, lymphangioma, and infarction. Median age at presentation was 6 years, and 30 (57%) were female. Masses were initially noticed on imaging studies performed for unrelated symptoms in 33 children (62%), laboratory abnormalities consistent with liver disease in 11 (21%), and palpable abdominal masses in 9 (17%). Diagnosis was made based on characteristic radiographic findings in 31 (58%), but histopathological examination was required for the remaining 22 (42%). Of the 53 children, 27 (51%) were under observation while 17 (32%) had masses resected. Medications targeting masses were used in 9 (17%) and liver transplantation was performed in 4 (8%). The only death (2%) occurred in a child with multifocal IHH unresponsive to medical management and prior to liver transplant availability. CONCLUSIONS: IHH and focal nodular hyperplasia were the most common lesions. The majority of benign lesions were found incidentally and diagnosed radiologically. Expectant management was sufficient in most children after diagnosis, although surgical intervention including liver transplant was occasionally necessary.