Optimizing pediatric liver transplantation: Evaluating the impact of donor age and graft type on patient survival outcome.

BACKGROUND: We examined the combined effects of donor age and graft type on pediatric liver transplantation outcomes with an aim to offer insights into the strategic utilization of these donor and graft options. METHODS: A retrospective analysis was conducted using a national database on 0-2-year-old (N = 2714) and 3-17-year-old (N = 2263) pediatric recipients. These recipients were categorized based on donor age (≥40 vs <40 years) and graft type. Survival outcomes were analyzed using the Kaplan-Meier and Cox proportional hazards models, followed by an intention-to-treat (ITT) analysis to examine overall patient survival. RESULTS: Living and younger donors generally resulted in better outcomes compared to deceased and older donors, respectively. This difference was more significant among younger recipients (0-2 years compared to 3-17 years). Despite this finding, ITT survival analysis showed that donor age and graft type did not impact survival with the exception of 0-2-year-old recipients who had an improved survival with a younger living donor graft. CONCLUSIONS: Timely transplantation has the largest impact on survival in pediatric recipients. Improving waitlist mortality requires uniform surgical expertise at many transplant centers to provide technical variant graft (TVG) options and shed the conservative mindset of seeking only the "best" graft for pediatric recipients.

A retrospective cohort study of socioeconomic deprivation and post-liver transplant survival in adults.

The Area Deprivation Index is a granular measure of neighborhood socioeconomic deprivation. The relationship between neighborhood socioeconomic deprivation and recipient survival following liver transplantation (LT) is unclear. To investigate this, the authors performed a retrospective cohort study of adults who underwent LT at the University of Washington Medical Center from January 1, 2004, to December 31, 2020. The primary exposure was a degree of neighborhood socioeconomic deprivation as determined by the Area Deprivation Index score. The primary outcome was posttransplant recipient mortality. In a multivariable Cox proportional analysis, LT recipients from high-deprivation areas had a higher risk of mortality than those from low-deprivation areas (HR: 1.81; 95% CI: 1.03-3.18, p =0.04). Notably, the difference in mortality between area deprivation groups did not become statistically significant until 6 years after transplantation. In summary, LT recipients experiencing high socioeconomic deprivation tended to have worse posttransplant survival. Further research is needed to elucidate the extent to which neighborhood socioeconomic deprivation contributes to mortality risk and identify effective measures to improve survival in more socioeconomically disadvantaged LT recipients.

Transplant renal vein stent placement complicated by obstructive hematuria: A case report.

BACKGROUND: Renal vein stenosis is uncommon following transplantation. We report acute renal vein stenosis post-transplant treated with an endovascular stent and complicated by urinary obstruction from clot formation. METHODS: Retrospective case report. RESULTS: A 16-year-old female 3 years post-transplant suffered anuria post-stenting with renal ultrasound demonstrating obstructive clot in the collecting system, a previously unreported complication. Subsequent nephroureteral JJ stent placement resulted in high-volume urine output. CONCLUSION: This article underscores the high index of suspicion required for renal vein stenosis following transplantation and the need to monitor urine output closely following stent placement.

An ethical analysis of obesity as a contraindication to pediatric liver transplant candidacy.

Childhood obesity is becoming more prevalent in the United States (US) and worldwide, including among children in need of a liver transplant. Unlike with heart and kidney failure, end-stage liver disease (ESLD) is unique in that no widely available medical technology can re-create the life-sustaining function of a failing liver. Therefore, delaying a life-saving liver transplant for weight loss, for example, is much harder, if not impossible for many pediatric patients, especially those with acute liver failure. For adults in the United States, guidelines consider obesity a contraindication to liver transplant. Although formal guidelines are lacking in children, many pediatric transplant centers also consider obesity a contraindication to a pediatric liver transplant. Variations in practice among pediatric institutions may result in biased and ad hoc decisions that worsen healthcare inequities. In this article, we define and report the prevalence of childhood obesity among children with ESLD, review existing guidelines for liver transplant in adults with obesity, examine pediatric liver transplant outcomes, and discuss the ethical considerations of using obesity as a contraindication to pediatric liver transplant informed by the principles of utility, justice, and respect for persons.

Contrast-enhanced voiding urosonography (CEVUS) as a safe alternate means of assessing vesicoureteral reflux in pediatric kidney transplant patients.

BACKGROUND: Although voiding cystourethrogram (VCUG) is currently the gold standard in VUR evaluation, there is ionizing radiation exposure. Contrast-enhanced voiding urosonography (CEVUS) uses ultrasound contrast agents to visualize the urinary tract and has been reported to be safe and effective in VUR evaluation in children. CEVUS application has yet to be specifically described in VUR evaluation in the pediatric kidney transplant population. The purpose of this study was to report the use of CEVUS and VCUG in evaluating and managing VUR in pediatric renal transplant patients. METHODS: Retrospective review was conducted for pediatric kidney transplant patients (18 years and younger) who underwent VCUG or CEVUS to assess for transplant VUR from July 2019 through June 2021. Demographic information, reason for VUR evaluation, fluoroscopy time, and postimaging complications were evaluated. Costs of imaging modalities were also considered. RESULTS: Eight patients were evaluated for transplant VUR during the study period. Of the 3 patients who underwent VCUG, all 3 had VUR (median grade 3). Median fluoroscopy time was 18 s and dose-area product was 18.7 uGy*m2 . Of the 5 patients who underwent CEVUS, 4 had VUR (median grade 4). There were no complications for either modality. Based on clinical and radiographic findings, patients were recommended no intervention, behavioral modification, or ureteral reimplantation. The total cost of CEVUS was $800 less than that of VCUG. CONCLUSION: CEVUS can provide an alternate means of safely evaluating VUR in kidney transplant patients with similar outcomes, potentially lower costs, and no exposure to ionizing radiation.

Use of DCD organs: Expanding the donor pool to increase pediatric transplantation.

The number of children being listed for transplant continues to be greater than the number of available organs. In fact, over the past decade, rates of liver and kidney transplants in pediatric transplantation are essentially unchanged (Am J Transplant. 2020;20:193 and Am J Transplant. 2020;20:20). The use of DCD donors offers a potential solution to organ scarcity; however, the use of DCD organs in pediatric transplantation remains a rare event. Pediatric transplants done using carefully chosen DCD donor organs have shown to have outcomes similar to those seen with the use of donation after brain death (DBD) donors. Herein, we review the literature to examine the utilization of DCD livers and kidneys, outcomes of these allografts, and assess if DCD organs are a viable method to increase organ availability in pediatric transplantation.

An ethical analysis of obesity as a contraindication of pediatric kidney transplant candidacy.

The inclusion of body mass index (BMI) as a criterion for determining kidney transplant candidacy in children raises clinical and ethical challenges. Childhood obesity is on the rise and common among children with kidney failure. In addition, obesity is reported as an independent risk factor for the development of CKD and kidney failure. Resultantly, more children with obesity are anticipated to need kidney transplants. Most transplant centers around the world use high BMI as a relative or absolute contraindication for kidney transplant. However, use of obesity as a relative or absolute contraindication for pediatric kidney transplant is controversial. Empirical data demonstrating poorer outcomes following kidney transplant in obese pediatric patients are limited. In addition, pediatric obesity is distributed inequitably among groups. Unlike adults, most children lack independent agency to choose their food sources and exercise opportunities; they are dependent on their families for these choices. In this paper, we define childhood obesity and review (1) the association and impact of obesity on kidney disease and kidney transplant, (2) existing adult guidelines and rationale for using high BMI as a criterion for kidney transplant, (3) the prevalence of childhood obesity among children with kidney failure, and (4) the existing literature on obesity and pediatric kidney transplant outcomes. We then discuss ethical considerations related to the use of obesity as a criterion for kidney transplant.

Identifying Liver Transplant Candidates at Risk of Wait List Removal Due to Nonadherence Using a Quality-of-Life Survey: A Competing Risk Analysis.

OBJECTIVES: We investigated whether the Liver Disease Health-Related Quality of Life Short Form or the Area Deprivation Index could be used to help identify liver transplant candidates at risk of delisting due to nonadherence. MATERIALS AND METHODS: We conducted a retrospective study of 358 adults (≥18 years old) listed for liver transplant at the University of Washington Medical Center from September 1, 2012, to August 30, 2017, who completed the Liver Disease Health-Related Quality of Life Short Form prior to listing. Wait list removal because of substance use or lack of attendance to clinical appointments was prospectively determined by a multidisciplinary transplant committee. A competing risk analysis was used to estimate risk of delisting for nonadherence. RESULTS: Among 358 liver transplant candidates, delisting occurred in 23 patients (6.4%) for nonadherence, 205 (57.3%) for transplant, 79 (22.1%) because of death or too sick, and 51 (14.2%) for other reasons. In the multivariable competing risk analysis, Liver Disease Health-Related Quality of Life Short Form responses indicating "poor memory" (subdistribution hazard ratio: 3.53; 95% CI, 1.49-8.36; P = .004) and "poor future outlook" (subdistribution hazard ratio: 2.94; 95% CI, 1.07-8.07; P = .03) were associated with higher risk of delisting for nonadherence. Female sex (subdistribution hazard ratio: 0.31; 95% CI, 0.10-0.93; P = .04) and previous abdominal surgery (subdistribution hazard ratio: 0.36; 95% CI, 0.14-0.92; P = .03) were associated with lower risk of delisting for nonadherence. The Area Deprivation Index was not associated with wait list removal. CONCLUSIONS: Liver Disease Health-Related Quality of Life Short Form responses indicating "poor memory" and "poor future outlook" were associated with increased risk of wait list removal due to nonadherence. Proactively identifying patients at high risk of nonadherence may help transplant programs better direct resources toward helping patients improve adherence and avoid delisting.

Gender and racial disparities in the transplant surgery workforce.

PURPOSE OF REVIEW: This review explores trends in the United States (US) transplant surgery workforce with a focus on historical demographics, post-fellowship job market, and quality of life reported by transplant surgeons. Ongoing efforts to improve women and racial/ethnic minority representation in transplant surgery are highlighted. Future directions to create a transplant workforce that reflects the diversity of the US population are discussed. RECENT FINDINGS: Representation of women and racial and ethnic minorities among transplant surgeons is minimal. Although recent data shows an improvement in the number of Black transplant surgeons from 2% to 5.5% and an increase in women to 12%, the White to Non-White transplant workforce ratio has increased 35% from 2000 to 2013. Transplant surgeons report an average of 4.3 call nights per week and less than five leisure days a month. Transplant ranks 1st among surgical sub-specialties in the prevalence of three well-studied facets of burnout. Concerns about lifestyle may contribute to the decreasing demand for advanced training in abdominal transplantation by US graduates. SUMMARY: Minimal improvements have been made in transplant surgery workforce diversity. Sustained and intentional recruitment and promotion efforts are needed to improve the representation of women and minority physicians and advanced practice providers in the field.

Donor-Recipient BSA Matching Is Prognostically Significant in Solitary and En Bloc Kidney Transplantation From Pediatric Circulatory Death Donors.

BACKGROUND: As the rate of early postoperative complications decline after transplant with pediatric donation after circulatory death (DCD) kidneys, attention has shifted to the long-term consequences of donor-recipient (D-R) size disparity given the pernicious systemic effects of inadequate functional nephron mass. METHODS: We conducted a retrospective cohort study using Organ Procurement and Transplantation Network data for all adult (aged ≥18 y) recipients of pediatric (aged 0-17 y) DCD kidneys in the United States from January 1, 2004 to March 10, 2020. RESULTS: DCD pediatric allografts transplanted between D-R pairs with a body surface area (BSA) ratio of 0.10-0.70 carried an increased risk of all-cause graft failure (relative risk [RR], 1.36; 95% confidence interval [CI], 1.10-1.69) and patient death (RR, 1.32; 95% CI, 1.01-1.73) when compared with pairings with a ratio of >0.91. Conversely, similar graft and patient survivals were demonstrated among the >0.70-0.91 and >0.91 cohorts. Furthermore, we found no difference in death-censored graft survival between all groups. Survival analysis revealed improved 10-y patient survival in recipients of en bloc allografts (P = 0.02) compared with recipients of single kidneys with D-R BSA ratios of 0.10-0.70. A similar survival advantage was demonstrated in recipients of solitary allografts with D-R BSA ratios >0.70 compared with the 0.10-0.70 cohort (P = 0.02). CONCLUSIONS: Inferior patient survival is likely associated with systemic sequelae of insufficient renal functional capacity in size-disparate DCD kidney recipients, which can be overcome by appropriate BSA matching or en bloc transplantation. We therefore suggest that in DCD kidney transplantation, D-R BSA ratios of 0.10-0.70 serve as criteria for en bloc allocation or alternative recipient selection to optimize the D-R BSA ratio to >0.70.

Pediatric biliary disorders: Multimodality imaging evaluation with clinicopathologic correlation.

The spectrum of pathologies affecting the biliary tree in the pediatric population varies depending on the age of presentation. While in utero insults can result in an array of anatomic variants and congenital anomalies in newborns, diverse acquired biliary pathologies are observed in older children. These acquired pathologies display different presentations and consequences than adults. Multimodality imaging assessment of the pediatric biliary system is requisite to establishing an appropriate management plan. Awareness of the imaging features of the various biliary pathologies and conveying clinically actionable information is essential to facilitate appropriate patient management. In this paper, we will illustrate the anatomy and embryology of the pediatric biliary system. Then, we will provide an overview of the imaging modalities used to assess the biliary system. Finally, we will review the unique features of the pediatric biliary pathologies, complemented by histopathologic correlation and discussions of clinical management.

Do funding sources influence long-term patient survival in pediatric liver transplantation?

BACKGROUND: Socioeconomic status has been associated with inferior outcomes after multiple surgical procedures, but has not been well studied with respect to pediatric liver transplantation. This study evaluated the impact of insurance status (as a proxy for socioeconomic status) on patient and allograft survival in pediatric first-time liver transplant recipients. METHODS: Our retrospective analysis of the UNOS data base from January 2002 through September 2017 revealed 6997 pediatric patients undergoing first-time isolated liver transplantation. A mixed Cox proportional hazards model adjusted for donor, recipient, and program characteristics determined the RR of insurance status on allograft and patient survival. All results were considered significant at P < .05. All statistical results were obtained using R version 3.5.1 and coxme version 2.2-10. RESULTS: Medicaid status had a significant negative impact on long-term survival after controlling for multiple covariates. Pediatric patients undergoing first-time isolated liver transplantation with Medicaid insurance had a RR of 1.42 [confidence interval: 1.18-1.60] of post-transplant death. CONCLUSION: Pediatric patients undergoing first-time isolated liver transplantation have multiple risk factors that may impact long-term survival. Having Medicaid insurance almost doubles the chances of dying post-liver transplant. This patient population may require more global support post-transplant to improve long-term survival.

Extinguishing burnout: National analysis of predictors and effects of burnout in abdominal transplant surgery fellows.

Burnout among surgeons has been attributed to increased workload and decreased autonomy. Although prior studies have examined burnout among transplant surgeons, no studies have evaluated burnout in abdominal transplant surgery fellows. The objective of our study was to identify predictors of burnout and understand its impact on personal and patient care during fellowship. A survey was sent to all abdominal transplant surgery fellows in an American Society of Transplant Surgeons-accredited fellowship. The response rate was 59.2% (n = 77) and 22.7% (n = 17) of fellows met criteria for burnout. Fellows with lower grit scores were more likely to exhibit burnout compared with fellows with higher scores (3.6 vs 4.0, P = .026). Those with burnout were more likely to work >100 hours per week (58.8% vs 27.6%, P = .023), have severe work-related stress (58.8% vs 22.4%, P = .010), consider quitting fellowship (94.1% vs 20.7%, P < .001), or make a medical error (35.3% vs 5.2%, P = .003). This national analysis of abdominal transplant fellows found that burnout rates are relatively low, but few fellows engage in self-care. Personal and program-related factors attribute to burnout and it has unacceptable effects on patient care. Transplant societies and fellowship programs should develop interventions to give fellows tools to prevent and combat burnout.

Decreased Incidence of Hepatic Artery Thrombosis in Pediatric Liver Transplantation Using Technical Variant Grafts: Report of the Society of Pediatric Liver Transplantation Experience.

OBJECTIVE: To evaluate risk factors for hepatic artery thrombosis (HAT) and examine the long-term outcomes of graft and patient survival after HAT in pediatric recipients of liver transplantation. STUDY DESIGN: Using multicenter data from the Society of Pediatric Liver Transplantation, Kaplan-Meier and Cox regression analyses were performed on first-time pediatric (aged <18 years) liver transplant recipients (n = 3801) in the US and Canada between 1995 and 2016. RESULTS: Of children undergoing their first liver transplantation, 7.4% developed HAT within the first 90 days of transplantation and, of those who were retransplanted, 20.7% developed recurrent HAT. Prolonged warm ischemia times increased the odds of developing HAT (OR, 1.11; P = .02). Adolescents aged 11-17 years (OR, 0.53; P = .03) and recipients with split, reduced, or living donor grafts had decreased odds of HAT (OR, 0.59; P < .001 compared with whole grafts). Fifty percent of children who developed HAT developed graft failure within the first 90 days of transplantation (adjusted hazard ratio, 11.87; 95% CI, 9.02-15.62) and had a significantly higher post-transplant mortality within the first 90 days after transplantation (adjusted hazard ratio, 6.18; 95% CI, 4.01-9.53). CONCLUSIONS: These data from an international registry demonstrate poorer long-term graft and patient survival in pediatric recipients whose post-transplant course is complicated by HAT. Notably, recipients of technical variant grafts had lower odds of HAT compared with whole liver grafts.

Livers From Pediatric Donation After Circulatory Death Donors Represent a Viable and Underutilized Source of Allograft.

Despite increased numbers of donation after circulatory death (DCD) donors, pediatric DCD livers are underused. To investigate possible reasons for this discrepancy, we conducted a retrospective cohort study using 2 data sets from the Organ Procurement and Transplantation Network for all deceased liver donors and for all recipients of DCD liver transplants from March 8, 1993, to June 30, 2018. Pediatric (0-12 years) and adolescent (13-17 years) DCD donors were compared with those aged 18-40 years. We found that pediatric DCD allografts are recovered at a significantly lower rate than from 18-to-40-year-old donors (27.3% versus 56.3%; P < 0.001). However, once recovered, these organs are transplanted at a similar rate to those from the 18-to-40-year-old donor cohort (74.7% versus 74.2%). Significantly more pediatric DCD livers (odds ratio [OR], 3.75; confidence interval [CI], 3.14-4.47) were not recovered compared with adult organs, which were most commonly not recovered due to organ quality (10.2% versus 7.1%; P < 0.001). The 10-year relative risks (RRs) for graft failure and patient death were similar between pediatric and adult DCD donors, with adolescent DCD livers demonstrating improved outcomes. DCD livers transplanted into pediatric donors were protective against graft failure (RR, 0.46; 95% confidence interval [CI], 0.21-0.99) and patient death (RR, 0.16; 95% CI, 0.04-0.69). In conclusion, despite lower rates of recovery, pediatric DCD livers represent a viable organ source for certain adults and children.

The impact of public health service increased risk donors in pediatric liver transplantation.

Many transplant programs are reluctant to use organs from deceased donors designated as "PHS increased risk" due to misconceptions regarding the quality of those organs. This study evaluated the impact of PHS increased risk donors on patient and allograft survival in pediatric patients undergoing liver transplantation. Retrospective analysis of the UNOS database from January 2005 through September 2017 revealed 5615 pediatric patients who underwent isolated liver transplantation; of these, 5057 patients received primary isolated liver transplants and 558 patients received isolated liver retransplants. PHS increased risk organs were used in 6.7% and 5.4% of the children receiving primary isolated and retransplant livers, respectively. Cox proportional hazards models adjusted for donor and recipient characteristics determined the relative risk of PHS status on allograft and patient survival. Sicker children (those in ICU [P < .001] and on life support [P = .04]) were more likely to receive PHS increased risk donor organs. There were no differences in overall patient (P = .61) or allograft (P = .68) survival between pediatric patients receiving PHS positive vs PHS negative deceased donor organs; adjusted models also demonstrated no statistically significant differences in patient or allograft survival. Excellent patient and allograft survival can be accomplished with PHS increased risk organs.

Endovascular treatment of surgical mesoportal and portosystemic shunt dysfunction in pediatric patients.

BACKGROUND: Published data describing the endovascular treatment of dysfunctional mesoportal and portosystemic shunts in the pediatric population are limited. OBJECTIVE: We sought to describe the treatment and follow-up of such shunts managed by interventional radiology at a single pediatric hospital. We hypothesized that stenotic and occluded pediatric portosystemic and mesoportal shunts can be maintained patent by interventional radiology in the moderate term. MATERIALS AND METHODS: We conducted a single-center retrospective study at a tertiary pediatric hospital. We included children with surgical mesoportal (meso-Rex) or portosystemic (mesocaval, splenorenal or splenocaval) shunts treated with attempted angioplasty or stenting from 2010 to 2018. Technical success was defined as catheterization and intervention upon the shunt with venographic evidence of flow improvement. The primary outcome variables were shunt patency at 1 month, 6 months, 12 months and 24 months post-procedure and freedom from reintervention. RESULTS: Twenty pediatric patients (11 boys, 9 girls; mean age 8.25 years, range 1.3-17 years) met inclusion criteria. Fifty-two interventions (primary and reintervention) on 13 splenorenal, 3 meso-Rex, 2 mesocaval and 2 splenocaval shunts were performed because of evidence of shunt failure, including gastrointestinal bleeding, hypersplenism, or radiographic evidence of a flow defect. The 11 stenotic shunts were treated with 100% technical success, while the remaining 9 occluded shunts were treated with 66.7% technical success. The mean number of reinterventions was 1.9 (standard deviation [SD] = 3.1) per child, which did not differ between stenotic and occluded shunts (P=0.24). Primary patency at 1-month, 6-month, 12-month and 24-months follow-up visits was 17/17 (100%), 10/16 (62.5%), 7/15 (46.7%) and 4/10 (40%), respectively. However, 100% of shunts were either primary patent or primary-assisted patent by endovascular reintervention. There were no cases of shunt occlusion following initial technical success. Finally, the median freedom from reintervention duration was 387 days (SD=821 days). CONCLUSION: Dysfunctional portosystemic surgical shunts are effectively managed by endovascular methods. While many shunts require reintervention, combined primary patency and assisted primary patency rates are excellent.

Doppler ultrasound predictors of transplant hepatic venous outflow obstruction in pediatric patients.

OBJECTIVE: To investigate Doppler US and catheter venogram correlates to improve detection of transplant HVOO and avoid unnecessary invasive imaging procedures. MATERIALS AND METHODS: A retrospective review was performed in all pediatric OLT patients undergoing catheter venography of the hepatic veins between 2007 and 2017 at a single large tertiary pediatric liver transplant institution. RESULTS: Forty-four transplant hepatic venograms in 32 OLT patients were included (mean 1.38, range 1-4 venograms per patient). All venograms were preceded by an independent Doppler US examination. Twenty-one (47.7%) venograms were performed for the investigation of suspected HVOO based on Doppler US alone, 19 (43.2%) were performed for TJLB without suspected HVOO, 4 (9.1%) were performed for both. Sixteen (36.3%) instances of >50% anastomotic stenosis were identified. Mean peak anastomotic velocities were 208 cm/s and 116 cm/s in the presence and absence of a >50% venographic stenosis, respectively (P < 0.004). In all cases where there was a monophasic waveform seen on Doppler US, there was a > 50% stenosis seen on hepatic vein venogram. In all cases where a triphasic waveform was seen on Doppler US, there was no stenosis seen on hepatic vein venogram. CONCLUSION: While a Doppler US velocity threshold providing both high sensitivity and specificity has yet to be identified, increasing peak anastomotic velocity and decreasing intrahepatic venous velocity correlate strongly with venographic outflow stenosis. The presence of a triphasic intrahepatic waveform provides good NPV.