The High Incidence of Occult Carcinoma in Total Hepatectomy Specimens of Patients Treated for Unresectable Colorectal Liver Metastases With Liver Transplant.

OBJECTIVE: To describe the rate of occult carcinoma deposits in total hepatectomy specimens from patients treated with liver transplant (LT) for colorectal liver metastases (CRLM). BACKGROUND: Previous studies have shown that patients with CRLM treated with systemic therapy demonstrate a high rate of complete radiographic response or may have disappearing liver metastases. However, this does not necessarily translate into a complete pathologic response, and residual invasive cancer may be found in up to 80% of the disappearing tumors after resection. METHODS: Retrospective review of 14 patients who underwent LT for CRLM, at 2 centers. Radiographic and pathologic correlation of the number of tumors and their viability before and after LT was performed. RESULTS: The median (interquartile range) number of tumors at diagnosis was 11 (4-23). The median number of chemotherapy cycles was 24 (16-37). Hepatic artery infusion was used in 5 patients (35.7%); 6 (42.9%) underwent surgical resection, and 5 (35.7%) received locoregional therapy. The indication for LT was unresectability in 8 patients (57.1%) and liver failure secondary to oncologic treatment in the remaining 6 (42.9%). Before LT, 7 patients (50%) demonstrated fluorodeoxyglucose-avid tumors and 7 (50%) had a complete radiographic response. Histopathologically, 11 patients (78.6%) had a viable tumor. Nine (64.2%) of the 14 patients were found to have undiagnosed metastases on explant pathology, with at least 22 unaccounted viable tumors before LT. Furthermore, 4 (57.1%) of the 7 patients who demonstrated complete radiographic response harbored viable carcinoma on explant pathology. CONCLUSIONS: A complete radiographic response does not reliably predict a complete pathologic response. In patients with unresectable CRLM, total hepatectomy and LT represent a promising treatment options to prevent indolent disease progression from disappearing CRLM.

Saudi association for the study of liver diseases and transplantation position statement on the hepatology workforce in Saudi Arabia.

The field of hepatology has evolved significantly over the last two decades. Hepatology practice in Saudi Arabia (SA) was dominated by hepatitis B and C viruses but is now being overtaken by patients with non-alcoholic fatty liver disease. These patients require greater medical attention as their care is more complex compared to patients with viral hepatitis. In addition, liver transplantation (LT) has expanded significantly in SA over the last three decades. There is a necessity to increase the hepatology workforce to meet the demand in SA. The time has come to reinforce the transplant hepatology fellowship program, that was launched recently, and to develop a nurse practitioner practice model to meet these demands. In addition, SA is going through a health care reform to enhance health care delivery which may affect the financial compensation polices of various specialties including gastroenterology and hepatology. Therefore, the Saudi Association for the Study of Liver diseases and Transplantation (SASLT) established a task force to discuss the current and future demands in the hepatology workforce in SA, as well as to discuss different avenues of financial compensation for transplant hepatologists in LT centers.

Patient-specific genetic factors predict treatment failure in sofosbuvir-treated patients with chronic hepatitis C.

BACKGROUND & AIMS: According to pivotal clinical trials, cure rates for sofosbuvir-based antiviral therapy exceed 96%. Treatment failure is usually assumed to be because of virological resistance-associated substitutions or clinical risk factors, yet the role of patient-specific genetic factors has not been well explored. We determined if patient-specific genetic factors help predict patients likely to fail sofosbuvir treatment in real-world treatment situations. METHODS: We recruited sofosbuvir-treated patients with chronic hepatitis C from five Canadian treatment sites, and performed a case-control pharmacogenomics study assessing both previously published and novel genetic polymorphisms. Specifically studied were variants predicted to impair CES1-dependent production of sofosbuvir's active metabolite, interferon-λ signalling variants expected to impact a patient's immune response to the virus and an HLA variant associated with increased spontaneous and treatment-induced viral clearance. RESULTS: Three hundred and fifty-nine sofosbuvir-treated patients were available for analyses after exclusions, with 34 (9.5%) failing treatment. We identified CES1 variants as novel predictors for treatment failure in European patients (rs115629050 or rs4513095; odds ratio (OR): 5.43; 95% confidence interval (CI): 1.64-18.01; P = .0057), replicated associations with IFNL4 variants predicted to increase interferon-λ signalling (eg rs12979860; OR: 2.25; 95% CI: 1.25-4.06; P = .0071) and discovered a novel association with a coding variant predicted to enhance the activity of IFNL4's receptor (rs2834167 in IL10RB; OR: 1.81; 95% CI: 1.01-3.24; P = .047). CONCLUSIONS: Ultimately, this work demonstrates that patient-specific genetic factors could be used as a tool to identify patients at higher risk of treatment failure and allow for these patients to receive effective therapy sooner.

The Saudi Critical Care Society practice guidelines on the management of COVID-19 in the ICU: Therapy section.

BACKGROUND: The rapid increase in coronavirus disease 2019 (COVID-19) cases during the subsequent waves in Saudi Arabia and other countries prompted the Saudi Critical Care Society (SCCS) to put together a panel of experts to issue evidence-based recommendations for the management of COVID-19 in the intensive care unit (ICU). METHODS: The SCCS COVID-19 panel included 51 experts with expertise in critical care, respirology, infectious disease, epidemiology, emergency medicine, clinical pharmacy, nursing, respiratory therapy, methodology, and health policy. All members completed an electronic conflict of interest disclosure form. The panel addressed 9 questions that are related to the therapy of COVID-19 in the ICU. We identified relevant systematic reviews and clinical trials, then used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach as well as the evidence-to-decision framework (EtD) to assess the quality of evidence and generate recommendations. RESULTS: The SCCS COVID-19 panel issued 12 recommendations on pharmacotherapeutic interventions (immunomodulators, antiviral agents, and anticoagulants) for severe and critical COVID-19, of which 3 were strong recommendations and 9 were weak recommendations. CONCLUSION: The SCCS COVID-19 panel used the GRADE approach to formulate recommendations on therapy for COVID-19 in the ICU. The EtD framework allows adaptation of these recommendations in different contexts. The SCCS guideline committee will update recommendations as new evidence becomes available.

Novel variant in glycophorin c gene protects against ribavirin-induced anemia during chronic hepatitis C treatment.

BACKGROUND: The current use of ribavirin in difficult-to-cure chronic hepatitis C patients (HCV) and patients with severe respiratory infections is constrained by the issue of ribavirin-induced hemolytic anemia that affects 30% of treated patients, requiring dosage modification or discontinuation. Though some genetic variants have been identified predicting this adverse effect, known clinical and genetic factors do not entirely explain the risk of ribavirin-induced anemia. METHODS: We assessed the associations of previously identified variants in inosine triphosphatase (ITPA), solute carrier 28A2 (SLC28A2) and vitamin D receptor (VDR) genes with ribavirin-induced anemia defined as hemoglobin decline of ≥30 g/L on treatment, followed by a staged discovery (n = 114), replication (n = 74), and combined (n = 188) genome-wide association study to uncover potential new predictive variants. RESULTS: We identified a novel association in the gene coding glycophorin C (rs6741425; OR:0.12, 95%CI:0.04-0.34, P = 2.94 × 10-6) that predicts protection against ribavirin-induced anemia. We also replicated the associations of ITPA and VDR genetic variants with the development of ribavirin-induced anemia (rs1127354; OR:0.13, 95%CI:0.04-0.41, P = 8.66 ×10-5; and rs1544410; OR:1.65, 95%CI:1.01-2.70, P = 0.0437). CONCLUSIONS: GYPC variation affecting erythrocyte membrane strength is important in predicting risk for developing ribavirin-induced anemia. ITPA and VDR genetic variants are also important predictors of this adverse reaction.

The Rochester Relapse Risk Scale: Developing a Standardized Approach to Predicting Substance Relapse in Liver Transplant Candidates.

OBJECTIVES: Substance abuse is a risk factor for nonadherence and graft failure after orthotopic liver transplant. This study aimed to evaluate the ability of an internally developed tool, the Rochester Relapse Risk Scale, to predict substance relapse in liver transplant candidates. MATERIALS AND METHODS: This single-center, retrospective, observational study included adult patients evaluated for orthotopic liver transplant using the Rochester Relapse Risk Scale. Primary outcome was rate of substance relapse, as measured by the risk scale, which stratified patients into relapse risk levels based on the number of factors present. RESULTS: In total, 303 patients (71.6% men, 90.4% White, median age of 55 years [interquartile range, 49-60 y]) were included. Median follow-up time was 212 days (interquartile range, 73-661 d). Seventy-four patients (24.4%) relapsed at 127 days (interquartile range, 55-461 d) after evaluation, with 60.8% who relapsed within 6 months. Relapse rates correlated with assigned risk level, with 8.3% relapsing at low, 19.0% at low-moderate, 25.3% at moderate, 33.8% at moderate-high, and 40.0% at high risk. High-risk cohorts had significantly shorter median time to relapse versus low-risk cohorts (104 vs 154 days; P = .001). CONCLUSIONS: Assignment of relapse risk level according to the Rochester Relapse Risk Scale aligned with rates of relapse. Additional studies are needed to refine the tool, assess inter-rater reliability, and confirm findings in prospective, multicenter studies.

Use of COVID-19 vaccines in patients with liver disease and post-liver transplantation: Position statement of the Saudi association for the study of liver diseases and transplantation.

Patients with chronic liver disease (CLD) and liver transplant recipients are at increased risk of morbidity and mortality from coronavirus disease 2019 (COVID-19). Although several studies demonstrated the safety and efficacy of COVID-19 vaccines in the general population, data in CLD patients and liver transplant recipients are lacking. Two COVID-19 vaccines were approved by the Saudi Food and Drug Authority and rolled out to several million recipients in Saudi Arabia. These vaccines are mRNA-based vaccine BNT162b2 from Pfizer/BioNTech and adenovirus-based AZD1222 from Oxford/AstraZeneca from three manufacturing sites (EU Nodes, Serum Institute of India, and South Korea Bio). The Saudi Association for the Study of Liver diseases and Transplantation (SASLT) has reviewed the available evidence and issued interim recommendations for COVID-19 vaccination in CLD and liver transplant recipients. Since there is no evidence contradicting the safety and immunogenicity of the currently approved COVID-19 vaccines in patients with CLD and hepatobiliary cancer and liver transplant recipients, the SASLT recommends vaccination in those patient populations. CLD and hepatobiliary cancer patients and liver transplant recipients should be prioritized depending on the risk factors for severe COVID-19. In transplant recipients, the optimal timing of vaccination remains unknown; however, immunization is recommended after the initial immunosuppression phase. Patients with CLD and liver transplant candidates or recipients should be closely monitored after COVID-19 vaccination. These patient populations should be included in future clinical trials to provide further evidence on the efficacy and safety of COVID-19 vaccines.

Estimating the effect of increasing utilization of living donor liver transplantation using observational data.

There has been a recent increase in enthusiasm for expansion of living donor liver transplantation (LDLT) programmes. Using all adults initially placed on the waiting list in the United States, we estimated the risk of overall mortality under national strategies which differed in their utilization of LDLT. We used a generalization of inverse probability weighting which can estimate the effect of interventions in the setting of finite resources. From 2005 to 2015, 93 812 eligible individuals were added to the waitlist: 51 322 received deceased donor grafts while 1970 underwent LDLT. Individuals who underwent LDLT had more favourable prognostic factors, including lower mean MELD score at transplant (14.6 vs. 20.5). The 1-year, 5-year and 10-year cumulative incidence of death under the current level of LDLT utilization were 18.0% (95% CI: 17.8, 18.3%), 41.2% (95% CI: 40.8, 41.5%) and 57.4% (95% CI: 56.9, 57.9%) compared to 17.9% (95% CI: 17.7, 18.2%), 40.6% (95% CI: 40.2, 40.9%) and 56.4% (95% CI: 55.8, 56.9%) under a strategy which doubles LDLT utilization. Expansion of LDLT utilization would have a measurable, modest effect on the risk of mortality for the entire cohort of individuals who begin on the transplant waiting list.

Gastrointestinal and liver manifestations of COVID-19.

The novel coronavirus 2 (SARS-CoV-2) has spread worldwide. While patients typically present with fever and symptoms of a respiratory illness, patients have also presented with gastrointestinal symptoms such as diarrhea, vomiting and abdominal pain. In addition, some patients were reported to have liver injury. In this article, we review gastrointestinal and liver aspects of COVID-19. In addition, we provide general gastroenterologists with guidance on the management of patients with gastrointestinal and liver disorders from COVID-19.

Cholestasis and disseminated histoplasmosis in a psoriatic patient on infliximab: case report and review of literature.

BACKGROUND: Histoplasma capsulatum is the most common endemic mycosis in the United States and frequently presents as an opportunistic infection in immunocompromised hosts. Though liver involvement is common in disseminated histoplasmosis, primary gastrointestinal histoplasmosis of the liver in absence of lung involvement is rare. Similarly, cholestatic granulomatous hepatitis in liver histoplasmosis is rarely seen. CASE PRESENTATION: We present a rare case of primary gastrointestinal histoplasmosis manifesting with acute granulomatous hepatitis and cholestasis in a 48-year-old female with psoriatic arthritis, receiving methotrexate and infliximab. The epidemiology, risk factors, clinical presentation, diagnosis, and treatment of histoplasmosis is discussed. Furthermore, we review the published cases of biopsy-proven disseminated histoplasmosis with cholestatic jaundice to highlight histoplasmosis involvement in the liver. CONCLUSION: Histoplasmosis should be considered in immunosuppressed patients with fever, chills, abdominal pain and cholestasis with progressive jaundice, particularly in subjects without evidence of biliary obstruction. Future studies are needed to accurately assess the risk of this fungal infection, specifically in patients on immunomodulatory therapy for autoimmune disease.

Saudi association for the study of liver diseases and transplantation position statement on liver transplantation during the COVID-19 pandemic.

The World Health Organization (WHO), on March 11th 2020, upgraded the status of the novel coronavirus disease (COVID-19) from epidemic to pandemic. Over two million individuals have been infected with SARS-CoV-2, the virus causing COVID-19, and as of April, 14th 2020, there were over 5000 confirmed cases in Saudi Arabia (SA). Many countries, including SA, have imposed major restrictions on travel, and everyday life, and the implications of these necessary changes are being felt in liver transplant (LT) centers in SA. Concerns remain that there is an increased risk for individuals over 65 years of age, with underlying medical conditions, or for those who are immunocompromised. Therefore, the Saudi Association for the Study of Liver Diseases and Transplantation (SASLT) established an urgent task force to launch a statement that can be utilized by LT centers as a guidance in the management of patients with advanced liver disease from the time of LT listing to the post-operative care of transplanted patients.

Extracorporeal liver support in patients with liver failure: a systematic review and meta-analysis of randomized trials.

PURPOSE: Acute liver failure (ALF) and acute on chronic liver failure (ACLF) are associated with significant mortality and morbidity. Extracorporeal liver support (ECLS) devices have been used as a bridge to liver transplant; however, the efficacy and safety of ECLS are unclear. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to examine the efficacy and safety of ECLS in liver failure. METHODS: We searched MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials from inception through March 13, 2019. RCTs comparing ECLS to usual care in ALF or ACLF were included. We used the Grading of Recommendations Assessment, Development and Evaluation approach to assess the certainty of the evidence. RESULTS: We identified 25 RCTs (1796 patients). ECLS use was associated with reduction in mortality (RR 0.84; 95% CI 0.74, 0.96, moderate certainty) and improvement in hepatic encephalopathy (HE) (RR 0.71; 95% CI 0.60, 0.84, low certainty) in patients with ALF or ACLF. The effect of ECLS on hypotension (RR 1.46; 95% CI 0.98, 2.2, low certainty), bleeding (RR 1.21; 95% CI 0.88, 1.66, moderate certainty), thrombocytopenia (RR 1.62; 95% CI 1.0, 2.64, very low certainty) and line infection (RR 1.92; 95% CI 0.11, 33.44, low certainty) was uncertain. CONCLUSIONS: ECLS may reduce mortality and improve HE in patients with ALF and ACLF. The effect on other outcomes is uncertain. However, the evidence is limited by risk of bias and imprecision, and larger trials are needed to better determine the effect of ECLS on patient-important outcomes.

Exercise Training for Liver Transplant Candidates.

BACKGROUND AND AIMS: Frailty is associated with increased morbidity and mortality, and this is tightly linked to liver decompensation and increased complication rates among liver transplant (LT) candidates. The aim of the study was to evaluate the efficacy of a structured in- and outpatient exercise training program for cirrhotic patients who were referred for liver transplant evaluation. METHODS: We retrospectively reviewed 458 consecutive LT patients. There were 200 patients who underwent LT prior to the implementation of an exercise training program (non-ETP) and 258 LT patients who underwent a comprehensive exercise training program (ETP). Baseline characteristics, readmission rate, and length of hospital stay (LOS) were analyzed and compared between the 2 groups. RESULTS: The ETP group were more likely to have diabetes mellitus and coronary artery disease. However, there was no significant difference in the postoperative complication rates between the 2 groups except for more infections in the ETP group compared to the non-ETP group. There was a trend toward lower 90-day readmission rate in the ETP group (17.9% vs 20%) and shorter LOS (14 vs 17 days). CONCLUSION: There was a trend toward reduced 90-day readmission and shorter length of stay after implementation of an exercise training program.

Position statement on the diagnosis and management of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is a major national and international health burden. It is one of the most common liver diseases worldwide and the most common cause of abnormal liver enzymes in many developed countries. Non-alcoholic fatty liver disease is also known as an important cause of cryptogenic cirrhosis and second leading cause for liver transplantation. It is commonly associated with metabolic syndrome. Non-alcoholic steatohepatitis (NASH) is the progressive phenotype of NAFLD. In spite of promising performance of non-invasive tools, liver biopsy remains the gold standard test for NASH diagnosis. Over decades, many drugs have been investigated in phase 2 and 3; however, no approved therapy to date. Despite the alarming global rates of NAFLD, there are no local community-based studies on the prevalence of NAFLD or local practice guidelines on its management; this expert review aims to fill this gap.

The role of imaging in determining prognosis for primary sclerosing cholangitis: A systematic review.

BACKGROUND/AIMS: Primary sclerosing cholangitis (PSC) is a chronic, progressive, fibrotic bile duct disease. Resultant complications include infection, progressive liver disease and cancer. While diagnosis relies extensively on imaging, the role of imaging in determining prognosis is unclear. The aim of this study was to systematically review existing imaging indices and features that predict PSC progression. MATERIALS AND METHODS: We performed a systematic review of imaging features that predict PSC progression. PubMed, EMBASE, MEDLINE, Clinicaltrials.gov and the Cochrane Library were searched from inception to November 2018 for relevant studies. Pertinent data were extracted and assessed. Study quality was evaluated using the Newcastle-Ottawa scale (NOS). RESULTS: The search returned 2504 results. Nine studies were included in the final review. Four studies evaluated the prognostic value of imaging features and five evaluated prognostic algorithms. The mean NOS score was 4.44 ± 0.98 on a scale of 0 to 9. Imaging features that were of prognostic value were degree of intrahepatic duct narrowing, the presence of a dominant biliary duct stricture and percentage of narrowed intraheptic ducts. Three imaging indices (one endoscopic retrograde cholangiopancreatography (ERCP)-based and two magnetic resonance-based) had been derived. The ERCP index was validated in a second cohort and subsequently updated to improve its predictive ability. The magnetic resonance cholangiopancreatography (MRCP) index was validated in two studies and was found to be predicative of transplant-free survival. A modified MRCP index (MRCP-risk score) was evaluated in a prospective multicenter study and was found to be predicative of PSC-related disease progression. CONCLUSION: In conclusion, ERCP and MRCP-based indices have short-term prognostic value in PSC. However, more studies are required to validate their predictability of disease-related progression, such as liver decompensation, ascending cholangitis, cholangiocarcinoma and liver transplantation.

Can we reduce ischemic cholangiopathy rates in donation after cardiac death liver transplantation after 10 years of practice? Canadian single-centre experience

Background: Outcomes in liver transplantation with organs obtained via donation after cardiocirculatory death (DCD) have been suboptimal compared to donation after brain death, attributed mainly to the high incidence of ischemic cholangiopathy (IC). We evaluated the effect of a 10-year learning curve on IC rates among DCD liver graft recipients at a single centre. Methods: We analyzed all DCD liver transplantation procedures from July 2006 to July 2016. Patients were grouped into early (July 2006 to June 2011) and late (July 2011 to July 2016) eras. Those with less than 6 months of follow-up were excluded. Primary outcomes were IC incidence and IC-free survival rate. Results: Among the 73 DCD liver transplantation procedures performed, 70 recipients fulfilled the selection criteria, 32 in the early era and 38 in the late era. Biliary complications were diagnosed in 19 recipients (27%). Ischemic cholangiopathy was observed in 8 patients (25%) in the early era and 1 patient (3%) in the late era (p = 0.005). The IC-free survival rate was higher in the late era than the early era (98% v. 79%, p = 0.01). The warm ischemia time (27 v. 24 min, p = 0.049) and functional warm ischemia time (21 v. 17 min, p = 0.002) were significantly lower in the late era than the early era. Conclusion: We found a significant reduction in IC rates and improvement in ICfree survival among DCD liver transplantation recipients after a learning curve period that was marked by more judicious donor selection with shorter procurement times.

Contexte: L'issue des greffes de foie suite à un don d'organe après décès cardiocirculatoire (DDC) a été sous-optimale comparativement aux dons suivant la mort cérébrale. Cela serait surtout attribuable à une forte incidence de cholangiopathie ischémique (CI). Nous avons évalué l'effet d'une courbe d'apprentissage échelonnée sur 10 ans sur les taux de CI chez des receveurs de greffe de foie après DDC dans un seul centre. Méthodes: Nous avons analysé toutes les greffes de foie consécutives à des DDC entre juillet 2006 et juillet 2016. Les patients ont été regroupés en 2 époques, la première, de juillet 2006 à juin 2011, et la seconde, de juillet 2011 à juillet 2016. Ceux pour lesquels on disposait de moins de 6 mois de suivi ont été exclus. Les paramètres principaux étaient l'incidence de CI et le taux de survie sans CI. Résultats: Parmi les 73 greffes de foie par suite de DDC, 70 receveurs répondaient aux critères de sélection, 32 pour la première époque et 38 pour la seconde époque. Des complications biliaires ont été diagnostiquées chez 19 receveurs (27 %). La cholangiopathie ischémique a été observée chez 8 patients (25 %) de la première époque et 1 patient (3 %) de la seconde (p = 0,005). Le taux de survie sans CI a été plus élevé pendant la seconde époque que pendant la première (98 % c. 79 %, p = 0,01). Le temps d'ischémie chaude (27 minutes c. 24, p = 0,049) et le temps d'ischémie chaude fonctionnelle (21 minutes c. 17, p = 0,002) ont été significativement plus courts durant la seconde époque que durant la première. Conclusion: Nous avons observé une réduction significative des taux de CI et une amélioration de la survie sans CI chez les receveurs de greffes de foie par DDC après une courbe d'apprentissage qui a été marquée par une sélection plus judicieuse des donneurs et des délais d'obtention plus courts.

The Effect of the Opioid Epidemic on Donation After Circulatory Death Transplantation Outcomes.

BACKGROUND: The opioid epidemic and the deaths of otherwise healthy individuals due to drug overdose in the United States has major implications for transplantation. The current extent and safety of utilization of liver and kidney grafts from donation after circulatory death (DCD) donors who died from opioid overdose is unknown. METHODS: Using national data from 2006 to 2016, we estimated the cumulative incidence of graft failure for recipients of DCD grafts, comparing the risk among recipients of organs from donors who died of anoxic drug overdose and recipients of organs from donors who died of other causes. RESULTS: One hundred seventy-nine (6.2%) of 2908 liver graft recipients and 944 (6.1%) of 15520 kidney graft recipients received grafts from donors who died of anoxic drug overdose. Grafts from anoxic drug overdose donors were less frequently used compared with other DCD grafts (liver, 25.9% versus 29.6%; 95% confidence interval [CI] for difference, -6.7% to -0.7%; kidney, 81.0% versus 84.7%; 95% CI for difference, -7.3% to -0.1%). However, the risk of graft failure at 5 years was similar for recipients of anoxic drug overdose donor grafts and recipients of other grafts (liver risk difference, 1.8%; 95% CI, -7.8% to 11.8%; kidney risk difference, -1.5%; 95% CI, -5.4% to 3.1%). CONCLUSIONS: In the context of the current opioid epidemic, utilization of anoxic drug overdose DCD donor grafts does not increase the risk of graft failure and may help to address waitlist demands.