Low volume is associated with worse patient outcomes for pediatric liver transplant centers

Center Volume and Survival Relationship for Neonates With Congenital Diaphragmatic Hernia Treated With Extracorporeal Life Support

OBJECTIVES

Literature is emerging regarding the role of center volume as an independent variable contributing to improved outcomes. A higher volume of index procedures may be associated with decreased morbidity and mortality. This association has not been examined for the subgroup of infants with congenital diaphragmatic hernia (CDH) receiving extracorporeal life support (ECLS). Our study aims to examine the risk-adjusted association between center volume and outcomes in CDH-ECLS neonates, hypothesizing that higher center volume confers a survival advantage.

DESIGN

Multicenter, retrospective comparative study using the Extracorporeal Life Support Organization database.

SETTING

One hundred twenty international pediatric centers.

PATIENTS

Neonates with CDH managed with ECLS from 2000 to 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The cohort included 4,985 neonates with a mortality rate of 50.6%. For the 120 centers studied, mean center volume was 42.4 ± 34.6 CDH ECLS cases over the 20-year study period. In an adjusted model, higher ECLS volume was associated with lower odds of mortality: odds ratio (OR) 0.995 (95% CI, 0.992-0.999; p = 0.014). For an increase in one sd in volume, that is, 1.75 cases annually, the OR for mortality was lower by 16.7%. Volume was examined as a categorical exposure variable where low-volume centers (fewer than 2 cases/yr) were associated with 54% higher odds of mortality (OR, 1.54; 95% CI, 1.03-2.29) compared with high-volume centers. On-ECLS complications (mechanical, neurologic, cardiac, hematologic metabolic, and renal) were not associated with volume. The likelihood of infectious complications was higher for low- (OR, 1.90; 95% CI, 1.06-3.40) and medium-volume (OR, 1.87; 95% CI, 1.03-3.39) compared with high-volume centers.

CONCLUSIONS

In this study, a survival advantage directly proportional to center volume was observed for CDH patients managed with ECLS. There was no significant difference in most complication rates. Future studies should aim to identify factors contributing to the higher mortality and morbidity observed at low-volume centers.

Integration of a dedicated management protocol in the care of pediatric liver cancer: From specialized providers to complication reduction

INTRODUCTION

Up to a third of children undergoing partial hepatectomy for primary hepatic malignancies experience at least one perioperative complication, with a presumed deleterious effect on both short- and long-term outcomes. We implemented a multidisciplinary treatment protocol in the management of these patients in order to improve complication rates following partial hepatectomy.

METHODS

A retrospective chart review was completed for all patients < 18 years of age who underwent liver resection at our institution between 2002 and 2019 for primary hepatic cancer. Demographic, intraoperative, postoperative, pathologic, and outcome data were analyzed for perioperative complications using the CLASSIC and Clavien-Dindo (CD) scales, event-free survival (EFS) and overall survival (OS).

RESULTS

A total of 73 patients were included in the analysis with 33 prior-to and 40 after dedicated provider protocol implementation. Perioperative complication rates decreased from 52% to 20% (p = 0.005) with major complications going from 18% to 10% (p = 0.31). On multivariable logistic regression, protocol implementation was associated with a reduction in any (OR 0.29 [95% CI 0.09 - 0.89]) but not major complications. On multivariate cox models, post protocol implementation was associated with improved event free survival (EFS) (HR 0.19 (0.036 - 0.195). Among patients with a diagnosis of hepatoblastoma (n = 62), the occurrence of a major perioperative complication was associated with a worse EFS (HR=5.45, p = 0.03) on multivariate analysis, however this did not translate into an impact on overall survival.

CONCLUSIONS

Our results demonstrate that, for children with primary liver malignancies, a dedication of patients to high-volume surgeons can improve rates of complications of liver resections and may improve the oncological outcome of hepatoblastoma.

Living donor liver transplant outcomes during the COVID-19 pandemic: does a decrease in case volume impact the overall outcomes?

Background

High-volume centers (HVCs) are classically associated with better outcomes. During the coronavirus disease 2019 (COVID-19) pandemic, there has been a decrease in the regular liver transplantation (LT) activity at our center. This study analyzed the effect of the decline in LT on posttransplant patient outcomes at our HVC.

Methods

We compared the surgical outcomes of patients who underwent LT during the COVID-19 pandemic lockdown (April 1, 2020 to September 30, 2020) with outcomes in the pre-pandemic calendar year (April 1, 2019 to March 31, 2020).

Results

During the 6 months of pandemic lockdown, 60 patients underwent LT (43 adults and 17 children) while 228 patients underwent LT (178 adults and 50 children) during the pre-pandemic calendar year. Patients in the pandemic group had significantly higher model for end-stage liver disease (MELD) scores (24.39±9.55 vs. 21.14±9.17, P=0.034), Child-Turcotte-Pugh scores (11.46±2.32 vs. 10.25±2.24, P=0.03), and incidence of acute-on-chronic liver failure (30.2% vs. 10.2%, P=0.002). Despite performing LT in sicker patients with COVID-19-related challenges, the 30-day (14% vs. 18.5%, P=0.479), 3-month (16.3% vs. 20.2%, P=0.557), and 6-month mortality rates (23.3% vs. 28.7%, P=0.477) were lower, but not statistically significant when compared to the pre-pandemic cohort.

Conclusions

During the COVID-19 pandemic lockdown the number of LT procedures performed at our HVC declined by half because prevailing conditions allowed LT in very sick patients only. Despite these changes, outcomes were not inferior during the pandemic period compared to the pre-pandemic calendar year. Greater individualization of patient care contributed to non-inferior outcomes in these sick recipients.

Learning Curve Analysis of Microvascular Hepatic Artery Anastomosis for Pediatric Living Donor Liver Transplantation: Initial Experience at A Single Institution

Background

The incidence of hepatic artery thrombosis in pediatric living donor liver transplantation (LDLT) is significantly higher than that in adults, and is closely related to the surgeon’s experience with hepatic artery anastomosis. However, there are few studies on the learning curve of hepatic artery anastomosis among surgeons.

Methods

We collected data related to 75 patients who underwent pediatric LDLT and hepatic artery anastomosis independently by the same surgeon. Cumulative sum method (CUSUM) was used to analyse the duration of hepatic artery anastomosis and determine the cut-off value. Patients were divided into two phases according to CUSUM. We analysed the intraoperative and postoperative data and survival outcomes of the included patients.

Results

Total anastomosis duration decreased with an increased number of completed procedures, and the average duration was 42.4 ± 2.20 min. A cut-off value and two phases were identified: 1–43 cases and 44–75 cases. Intraoperative blood loss was significantly lower in phase 2 than in phase 1. The immediate functional changes of total bilirubin (TBIL) and direct bilirubin (DBIL) were significantly also lower in phase 2 than in phase 1. Other functional outcomes, postoperative complications, and the long-term survival rate were not significantly different between the two phases.

Conclusions

Technical competence in pediatric LDLT hepatic artery anastomosis may be achieved after completing 43 cases. It is a safe procedure with a surgical loupe that can be systematized and adopted by pediatric surgeons with sufficient experience via a relatively long learning curve.

Immunologic benefits of maternal living donor allografts in pediatric liver transplantation: fewer rejection episodes and no evidence of de novo allosensitization

BACKGROUND

Pediatric liver transplant (LT) recipients of maternal living liver donor (LLD) grafts have been reported to experience fewer rejection episodes. However, it is unclear whether this benefit translates to reduction in developing donor-specific antibody (DSA) among maternal-LLD recipients. The aim of this study was to compare immunologic outcomes among maternal-LLD, non-maternal-LLD, and deceased donor liver transplant (DDLT) recipients.

METHODS

Children (≤18 years) who underwent LT between 1/1998 and 12/2019 at two high-volume LT centers in North America were evaluated. Patients were divided into three groups by type of graft received (maternal-LLD, non-maternal LLD, and DDLT). Clinical variables and outcomes were compared according to each graft type.

RESULTS

A total of 450 pediatric primary LT were analyzed: 275 (61.1%) DDLT, 73 (16.2%) maternal-LLD, and 102 (22.6%) non-maternal-LLD. Children receiving LLD grafts were less likely to develop rejection when compared to the DDLT group (DDLT 46.9% vs. maternal-LLD 31.5% vs. non-maternal-LLD 28.4%, p = 0.001). There was no difference in rejection rates between maternal and non-maternal-LLD recipients. A higher percentage of maternal-LLD recipients were on immunosuppression monotherapy compared to non-maternal-LLD and DDLT recipients (6.7% vs. 1.2 vs. 2.4%, respectively). A subgroup of 68 patients were tested for DSA post-LT. Maternal-LLD recipients were less likely to develop de novo DSA (maternal-LLD 11.8% vs. non-maternal-LLD 19.3% vs. DDLT 43%, p = 0.018). None of the maternal-LLD recipients developed antibody-mediated rejection.

CONCLUSIONS

These data support the concept of immunologic benefit of maternal-LLD in pediatric LT, with lower rates of rejection and allosensitization post-LT when compared to DDLT recipients.

Center Variability in Acute Rejection and Biliary Complications After Pediatric Liver Transplantation

Transplant center performance and practice variation for pediatric post-liver transplantation (LT) outcomes other than survival are understudied. This was a retrospective cohort study of pediatric LT recipients who received transplants between January 1, 2006, and May 31, 2017, using United Network for Organ Sharing (UNOS) data that were merged with the Pediatric Health Information System database. Center effects for the acute rejection rate at 1 year after LT (AR1) using UNOS coding and the biliary complication rate at 1 year after LT (BC1) using inpatient billing claims data were estimated by center-specific rescaled odds ratios that accounted for potential differences in recipient and donor characteristics. There were 2216 pediatric LT recipients at 24 freestanding children's hospitals in the United States during the study period. The median unadjusted center rate of AR1 was 36.92% (interquartile range [IQR], 22.36%-44.52%), whereas that of BC1 was 32.29% (IQR, 26.14%-40.44%). Accounting for recipient case mix and donor factors, 5/24 centers performed better than expected with regard to AR1, whereas 3/24 centers performed worse than expected. There was less heterogeneity across the center effects for BC1 than for AR1. There was no relationship observed between the center effects for AR1 or BC1 and center volume. Beyond recipient and allograft factors, differences in transplant center management are an important driver of center AR1 performance, and less so of BC1 performance. Further research is needed to identify the sources of variability so as to implement the most effective solutions to broadly enhance outcomes for pediatric LT recipients.

Worse Outcomes Associated With Liver Transplants: An Increasing Trend

Background and aim Since individuals in the early stages of liver cirrhosis are typically asymptomatic, the prevalence of liver cirrhosis may be underestimated. Liver cirrhosis has a significant morbidity and mortality rate, with 1.03 million deaths worldwide each year. For end-stage liver disease, liver transplantation is a potential therapeutic option. The goal of our research was to examine the current trend in liver transplants using data from a national database. Methods Using the International Classification of Diseases (ICD)-9 codes, we identified individuals who had a liver transplant during the index hospital admission in the Nationwide Inpatient Sample from 2007 to 2011. This national sample of patients is from the United States. We looked at the yearly trend in liver transplants and related outcomes, such as duration of hospitalization (DOH), hospital expenses, and mortality in the hospital. In order to find determinants of mortality, we used a multivariate analysis. Results There were 25,331 patients hospitalized (weighted for national estimate). Between 2007 and 2011, the number of transplants grew by 1.2%. The majority of transplant recipients were Caucasian (57%), with an average age of 54 years, had a private healthcare plan (53%), and had average earnings in the upper quartile by zip code (26%). Patients with a higher Charlson Comorbidity Index (79% had a score of four) were more likely to be admitted to a southern hospital (33%), an academic hospital (>99%), and a large capacity hospital (90%). Seventy percent of liver transplant recipients received cadaver donors. Hepatitis C was the most prevalent reason for transplant (30%), followed by hepatocellular carcinoma (HCC) (29%) and alcoholic liver disease (25%). In 2011, compared to 2007, there was an upward rise in fatality (from 3.8% to 5.1%), average hospital expenditures (from $335,504 to $498,369), and DOH (from 17.4 to 22.7 days). The cost of hospitalization was two billion dollars per year. The independent variables related to an increased mortality on multivariate analysis were African American race (OR: 2.0, 95%, CI: 1.2-3.2; p=0.005) and large capacity hospitals (OR: 2.5, 95% CI: 1.6-4.1; p=0.0002). Predictors linked to lower mortality included private healthcare coverage (vs. Medicare: OR: 0.7, 95%, CI: 0.51-0.97; p=0.03), academic hospital (OR: 0.6, 95% CI: 0.4-0.8; p=0.005), cadaver donor (OR: 0.6, 95% CI: 0.5-0.8; p=0.002), HCC (OR: 0.6, 95% CI: 0.4-0.9; p=0.01), and non-alcoholic steatohepatitis (NASH) cirrhosis (OR: 0.4, 95% CI: 0.2-0.9; p=0.02). Conclusion Our study found an increasing trend in worse outcomes (increased mortality, average hospital costs, and average DOH) after a liver transplant. Patients of the African American race and large capacity hospitals were associated with a higher risk of death, whereas private healthcare plans, academic hospitals, cadaver donors, HCC, and NASH cirrhosis were associated with a lower risk.

Practice variation in the immediate postoperative care of pediatric liver transplant patients: Framework for a national consensus

Advancements in critical care management have led to improvement in pediatric LT outcomes. However, there are no specific guidelines for many aspects of immediate post-LT care. This survey examines practice variations in the immediate postoperative care of pediatric LT patients at a large number of active US centers. This study is a cross-sectional survey of medical directors at PALISI-affiliated PICU in the United States. Centers performing pediatric LT were analyzed. Study measures included PICU practices regarding staffing, composition of the multidisciplinary team, early post-LT graft and patient monitoring, and anticoagulation. Of the thirty-five responding centers, twenty-five had a LT program which accounted for one-half of all US pediatric LTs. For analysis, centers were categorized by volume: high (7), medium (11), and low (7). The majority of PICU teams included an intensivist (80%) and hepatologist (84%). High-volume centers were less likely to have 24-hour in-house attending coverage (29%, compared to 64% (medium) and 100% (low)). High-volume centers were most likely to have pre-printed orders, but least likely to have written PICU management protocols. Most centers utilize routine daily liver ultrasound. Routine prophylactic anticoagulation, and the agent of choice, was variable. There is marked inconsistency in post-LT practice across PALISI centers in regards to team composition and immediate post-LT management. A national US consensus for post-LT PICU practices would facilitate outcomes research and would establish a platform for multicenter studies.

Pediatric liver transplantation in Australia and New Zealand: The case for a collaborative anesthetic database

BACKGROUND

Liver transplantation is conducted with strict oversight of organizational structure and clinical practice. However, specific regulations pertaining to the delivery of anesthetic services are lacking and consideration of departmental structure and mechanisms for quality control must occur at a local level. Busy centers collect and process sufficient data to guide this process but those with low case loads may not generate enough data for useful analysis. In Australia and New Zealand, pediatric liver transplants are performed at only four locations. As these operations are not equally distributed geographically or temporally there are periods of low activity at some centers. As anesthesia affects patient outcome, quality assurance activities are important in this setting.

AIMS

Provide a global overview of the structure and function of liver transplantation networks. Identify issues related to provision of pediatric anesthetic services with specific reference to Australasia. Examine anesthetic data from a single pediatric center to illustrate benefits and limitations of such activity.

METHODS

Pediatric liver transplant centers from Australia and New Zealand were surveyed to determine the organizational and logistical issues related to a liver transplant service. An audit of 15 years of liver transplants from a single center was conducted for benchmarking purposes and to identify changes in anesthetic practice over time.

RESULTS

Pediatric liver transplants performed in Queensland from January 2005 to December 2019 were reviewed. Changes in transfusion practice reflected international trends. Morbidity and mortality were comparable to international data. Important complications such as hepatic artery and portal vein thrombosis were uncommon and did not generate enough data for further analysis.

CONCLUSIONS

Combining the anesthetic liver transplant data from all sites in a single registry would expand data collection and generate broadly applicable findings. We propose the establishment of an Australasian pediatric anesthetic liver transplant database.

Association of balanced abdominal organ transplant center volumes with patient outcomes

BACKGROUND

The volume-outcome relationship for organ-specific transplantation is well-described; it is unknown if the relative balance of kidney compared with liver volumes within an institution relates to organ-specific outcomes. We assessed the association between relative balance within a transplant center and outcomes.

METHODS

National retrospective analysis of isolated kidney and liver transplants in United States 2005-2014 followed through 2019. Latent class analysis defined transplant center phenotypes. Multivariate Cox models estimated death-censored graft loss and mortality.

RESULTS

Latent class analysis identified four phenotypes: kidney only (n = 117), kidney dominant (n = 36), mixed/balanced (n = 90), and liver dominant (n = 13). Compared to mixed centers, the risk of kidney graft loss was higher at kidney-dominant (HR 1.07, p < .001) and liver-dominant (HR 1.10, p < .001) centers, while kidney-only (HR 1.06, p = .01) centers had higher mortality. Liver graft loss was not associated with phenotype, but risk of patient death was lower (HR 0.93, p = .02) at liver dominant and higher (HR 1.06, p = .02) at kidney-dominant centers.

CONCLUSIONS

A mixed phenotype was associated with improved kidney transplant outcomes, whereas liver transplant outcomes were best at liver-dominant centers. While these findings need to be verified with center-level resources, optimization of shared resources could improve patient and organ outcomes.

Outcomes of Pediatric Liver Transplantation in Korea Using Two National Registries

Background: This retrospective study aimed to evaluate overall survival and the risk factors for mortality among Korean pediatric liver transplantation (LT) patients using data from two national registries: the Korean Network Organ Sharing (KONOS) of the Korea Centers for Disease Control and Prevention and the Korean Organ Transplantation Registry (KOTRY). Methods: Prospectively collected data of 755 pediatric patients who underwent primary LT (KONOS, February 2000 to December 2015; KOTRY, May 2014 to December 2017) were retrospectively reviewed. Results: The 1-, 5-, 10-, and 15-year survival rates were 90.6%, 86.7%, 85.8%, and 85.5%, respectively, in KONOS, and the 1-month, 3-month, 1-year, and 2-year survival rates were 92.1%, 89.4%, 89.4%, and 87.2%, respectively, in KOTRY. There was no significant difference in survival between the two registries. Multivariate analysis identified that body weight ≥6 kg (p <0.001), biliary atresia as underlying liver disease (p = 0.001), and high-volume center (p < 0.001) were associated with better survival according to the KONOS database, while hepatic artery complication (p < 0.001) was associated with poorer overall survival rates according to the KOTRY database. Conclusion: Long-term pediatric patient survival after LT was satisfactory in this Korean national registry analysis. However, children with risk factors for poor outcomes should be carefully managed after LT.

Most pediatric transplant centers are low volume, adult-focused, and in proximity to higher volume pediatric centers

BACKGROUND

Independent studies provide evidence that low volume pediatric solid organ transplant centers have inferior outcomes compared to high volume pediatric centers. The study assessed whether patients treated at low volume pediatric centers have access to higher volume pediatric centers, which offer potentially better outcomes.

METHODS

We analyzed center specific data on 467 pediatric solid organ transplant centers in the U.S using the Organ Procurement and Transplantation Network database from 2002 to 2014. The proximities of low volume pediatric centers to high volume pediatric centers were determined using Maptive, a tool based on Google Maps.

RESULTS

Most low volume pediatric transplant centers focused on transplantation of adults (84% heart, 83% liver, and 93% kidney programs). A majority of low volume pediatric centers (77% for heart, 53% for lung, 68% for liver and 90% for kidney) were within 150 miles of high volume centers. Among all children listed for transplantation, 30.7% were listed in low volume pediatric centers. Most low volume pediatric centers are adult focused and near high volume pediatric centers.

CONCLUSION

We need greater scrutiny of outcomes, particularly waitlist outcomes, of low volume pediatric solid organ transplant centers located close to high volume pediatric solid organ transplant centers.

TYPE OF STUDY AND LEVEL OF EVIDENCE

Retrospective Comparative Study, Level III.

Effect of Case Volume on Mortality After Pediatric Liver Transplantation in Korea

BACKGROUND

The purpose of this study was to evaluate whether institutional case-volume affects clinical outcomes after pediatric liver transplantation.

METHODS

We conducted a nationwide retrospective cohort study using the database of Korean National Healthcare Insurance Service. Between January 2007 and December 2016, 521 pediatric liver transplantations were performed at 22 centers in Korea. Centers were categorized according to the average annual number of liver transplantations: >10, 1 to 10, and <1.

RESULTS

In-hospital mortality rates in the high-, medium-, and low-volume centers were 5.8%, 12.5%, and 32.1%, respectively. After adjustment, in-hospital mortality was significantly higher in low-volume centers (adjusted odds ratio, 9.693; 95% confidence interval, 4.636-20.268; P < 0.001) and medium-volume centers (adjusted odds ratio, 3.393; 95% confidence interval, 1.980-5.813; P < 0.001) compared to high-volume centers. Long-term survival for up to 9 years was better in high-volume centers.

CONCLUSIONS

Centers with higher case volume (>10 pediatric liver transplantations/y) had better outcomes after pediatric liver transplantation, including in-hospital mortality and long-term mortality, compared to centers with lower case volume (≤10 liver transplantations/y).

Post-transplantation Outcomes in Patients with PA or MMA: A Review of the Literature

Introduction

Liver transplantation is recognised as a treatment option for patients with propionic acidemia (PA) and those with methylmalonic acidemia (MMA) without renal impairment. In patients with MMA and moderate-to-severe renal impairment, combined liver–kidney transplantation is indicated. However, clinical experience of these transplantation options in patients with PA and MMA remains limited and fragmented. We undertook an overview of post-transplantation outcomes in patients with PA and MMA using the current available evidence.

Methods

A literature search identified publications on the use of transplantation in patients with PA and MMA. Publications were considered if they presented adequate demographic and outcome data from patients with PA or MMA. Publications that did not report any specific outcomes for patients or provided insufficient data were excluded.

Results

Seventy publications were identified of which 38 were full papers. A total of 373 patients underwent liver/kidney/combined liver–kidney transplantation for PA or MMA. The most typical reason for transplantation was recurrent metabolic decompensation. A total of 27 post-transplant deaths were reported in patients with PA [14.0% (27/194)]. For patients with MMA, 18 post-transplant deaths were reported [11% (18/167)]. A total of 62 complications were reported in 115 patients with PA (54%) with cardiomyopathy (n = 12), hepatic arterial thrombosis (HAT; n = 14) and viral infections (n = 12) being the most commonly reported. A total of 52 complications were reported in 106 patients with MMA (49%) with viral infections (n = 14) and renal failure/impairment (n = 10) being the most commonly reported.

Conclusions

Liver transplantation and combined liver–kidney transplantation appears to benefit some patients with PA or MMA, respectively, but this approach does not provide complete correction of the metabolic defect and some patients remain at risk from disease-related and transplantation-related complications, including death. Thus, all treatment avenues should be exhausted before consideration of organ transplantation and the benefits of this approach must be weighed against the risk of perioperative complications on an individual basis.

A survey of the anesthetic management of pediatric kidney transplantation in France

BACKGROUND

Renal transplantation is the best available therapeutic option for end-stage renal failure in both children and adults. However, little is known about anesthetic practice during pediatric renal transplantation.

MATERIAL AND METHODS

The study consisted of a national survey about anesthetic practice during pediatric renal transplantation in France. French tertiary pediatric centers performing renal transplants were targeted, and one physician from each team was asked to complete the survey. The survey included patient data, preoperative assessment and optimization data, and intraoperative anesthesia data (drugs, ventilation, and hemodynamic interventions).

RESULTS

Twenty centers performing kidney transplantation were identified and contacted to complete the survey, and eight responded. Surveyed centers performed 96 of the 122 pediatric kidney transplantations performed in France in 2017 (79%). Centers consistently performed echocardiography and ultrasound examinations of the great veins preoperatively and consistently employed esophageal Doppler cardiac output estimation and vasopressors intraoperatively. All other practices were found to be heterogeneous. Central venous pressure was monitored in six centers, and dopamine was administered perioperatively in two centers.

CONCLUSIONS

The current study provides a snapshot of the perioperative management of pediatric kidney transplantation in France. Results emphasize the need for both standardization of practice and awareness of recent evidence against the use of CVP monitoring and dopamine infusions.

The Volume-outcome Relationship in Deceased Donor Kidney Transplantation and Implications for Regionalization

OBJECTIVE

The aim of this study was to investigate the volume-outcome relationship in kidney transplantation by examining graft and patient outcomes using standardized risk adjustment (observed-to-expected outcomes). A secondary objective was to examine the geographic proximity of low, medium, and high-volume kidney transplant centers in the United States.

SUMMARY OF BACKGROUND DATA

The significant survival benefit of kidney transplantation in the context of a severe shortage of donor organs mandates strategies to optimize outcomes. Unlike for other solid organ transplants, the relationship between surgical volume and kidney transplant outcomes has not been clearly established.

METHODS

The Scientific Registry of Transplant Recipients was used to examine national outcomes for adults undergoing deceased donor kidney transplantation from January 1, 1999 to December 31, 2013 (15-year study period). Observed-to-expected rates of graft loss and patient death were compared for low, medium, and high-volume centers. The geographic proximity of low-volume centers to higher volume centers was determined to assess the impact of regionalization on patient travel burden.

RESULTS

A total of 206,179 procedures were analyzed. Compared with low-volume centers, high-volume centers had significantly lower observed-to-expected rates of 1-month graft loss (0.93 vs 1.18, P<0.001), 1-year graft loss (0.97 vs 1.12, P<0.001), 1-month patient death (0.90 vs 1.29, P=0.005), and 1-year patient death (0.95 vs 1.15, P=0.001). Low-volume centers were frequently in close proximity to higher volume centers, with a median distance of 7 miles (interquartile range: 2 to 75).

CONCLUSIONS

A robust volume-outcome relationship was observed for deceased donor kidney transplantation, and low-volume centers are frequently in close proximity to higher volume centers. Increased regionalization could improve outcomes, but should be considered carefully in light of the potential negative impact on transplant volume and access to care.

Institutional volume affects long-term survival following lung transplantation in the USA

OBJECTIVES

The aim of this study was to evaluate the impact of institutional volume on long-term outcomes following lung transplantation (LTx) in the USA.

METHODS

Adults undergoing LTx were identified in the United Network for Organ Sharing registry. Patients were divided into equal size tertiles according to the institutional volume. All-cause mortality following LTx was evaluated using the risk-adjusted multivariable Cox regression and the Kaplan-Meier analyses, and compared between these volume cohorts at 3 points: 90 days, 1 year (excluding 90-day deaths) and 10 years (excluding 1-year deaths). Lowess smoothing plots and receiver-operating characteristic analyses were performed to identify optimal volume thresholds associated with long-term survival.

RESULTS

A total of 13 370 adult LTx recipients were identified. The mean annual centre volume was 33.6 ± 20.1. After risk adjustment, low-volume centres were found to be at increased risk for 90-day mortality, [hazard ratio (HR) 1.56, P < 0.001], 1-year mortality excluding 90-day deaths (HR 1.46, P < 0.001) and 10-year mortality excluding 1-year deaths (HR 1.22, P < 0.001). These findings persisted when the centre volume was modelled as a continuous variable. The Kaplan-Meier analysis also demonstrated significant reductions in survival at each of these time points for low-volume centres (each P < 0.001). The 10-year survival conditional on 1-year survival was 37.4% in high-volume centres vs 28.0% in low-volume centres (P < 0.001). The optimal annual volume threshold for long-term survival was 26 LTx/year.

CONCLUSIONS

The institutional volume impacts long-term survival following LTx, even after excluding deaths within the first post-transplant year. Identifying the processes of care that lead to longer survival in high-volume centres is prudent.

Should more donation after cardiac death livers be used in pediatric transplantation?

INTRODUCTION

There is a mismatch that exists in donor liver organ supply and demand. DCD livers represents a potential source to increase the number of liver grafts available for use in pediatric recipients; however, there has been hesitancy to use such organs. We evaluated patient and allograft outcomes in pediatric liver transplant recipients of DCD livers.

METHODS

The UNOS database was queried to examine outcomes in all liver transplant recipients from 1993 to 2017. Patients were then divided according to adult and pediatric status, DBD or DCD allograft status, and era of transplant. Donor and recipient demographic data were examined, and patient and allograft survival were calculated. A P-value of <0.05 was considered to be significant.

RESULTS

A total of 57 pediatric recipients received a DCD liver allograft. DCD recipients were older than DBD recipients. There was no difference in the final PELD score between the groups. There were no differences in causes of allograft failure between the DCD and DBD groups. Importantly, the overall allograft survival in the DCD and DBD groups was similar, as was allograft survival based on era.

CONCLUSION

Pediatric liver transplant recipients of DCD allografts have comparable patient and allograft survival when compared to DBD allograft recipients. Use of DCD allografts in the pediatric liver transplant population should be strongly considered to increase the donor organ pool.

The Shrinking Landscape of Pediatric Surgery: Is Less More?

The Fred MacLeod Lecture was given at the 49th Annual Canadian Association of Pediatric Surgeons meeting held October 5-7th, 2017, in Banff, Alberta, Canada.

Understanding the relationship between hospital volume and patient outcomes for infants with gastroschisis

BACKGROUND

For many surgical operations, there is a well-established relationship between surgical volume and outcome. We investigated whether this relationship exists for infants with gastroschisis.

METHODS

Using the Kids' Inpatient Database for years 2003, 2006, 2009, and 2012, we identified all patients undergoing gastroschisis repair. Controlling for patient characteristics and complexity of disease (comorbid intestinal atresia/perforation, necrotizing enterocolitis, and respiratory distress syndrome), we compared surgical outcomes (mortality, length of stay, and incidence of TPN cholestasis) by hospital volume based on quartile for gastroschisis cases treated per year.

RESULTS

We identified 7769 patients treated at 743 hospitals. The majority of hospitals were low-volume (n=445), while only 49 were high-volume. The overall mortality rate was 4.3%, and the median length of stay was 34days. Adjusting for clinical and demographic characteristics, patients treated at high-volume hospitals had similar rates of TPN cholestasis and similar mortality rates, but a higher chance for a prolonged length of stay compared to those treated at low-volume hospitals.

CONCLUSIONS

Using national data, we found that gastroschisis patients treated at high-volume hospitals did not have improved outcomes. The benefits of high-volume hospitals, which seem to be important for complex pediatric surgery, may not apply to treatment of gastroschisis.

LEVEL OF EVIDENCE

Level III Retrospective Study.

Inferior Outcomes on the Waiting List in Low-Volume Pediatric Heart Transplant Centers

Low case volume has been associated with poor outcomes in a wide spectrum of procedures. Our objective was to study the association of low case volume and worse outcomes in pediatric heart transplant centers, taking the novel approach of including waitlist outcomes in the analysis. We studied a cohort of 6482 candidates listed in the Organ Procurement and Transplantation Network for pediatric heart transplantation between 2002 and 2014; 4665 (72%) of the candidates underwent transplantation. Candidates were divided into groups according to the average annual transplantation volume of the listing center during the study period: more than 10, six to 10, three to five, or fewer than three transplantations. We used multivariate Cox regression analysis to identify independent risk factors for waitlist and posttransplantation mortality. Of the 6482 candidates, 24% were listed in low-volume centers (fewer than three annual transplantations). Of these listed candidates in low-volume centers, only 36% received a transplant versus 89% in high-volume centers (more than 10 annual transplantations) (p < 0.001). Listing at a low-volume center was the most significant risk factor for waitlist death (hazard ratio [HR] 4.5, 95% confidence interval [CI] 3.5-5.7 in multivariate Cox regression and HR 5.6, CI 4.4-7.3 in multivariate competing risk regression) and was significant for posttransplantation death (HR 1.27, 95% CI 1.0-1.6 in multivariate Cox regression). During the study period, one-fourth of pediatric transplant candidates were listed in low-volume transplant centers. These children had a limited transplantation rate and a much greater risk of dying while on the waitlist.

Poor outcomes for children on the wait list at low-volume kidney transplant centers in the United States

BACKGROUND

Low case volume has been associated with worse survival outcomes in solid organ transplantation. Our aim was to analyze wait-list outcomes in conjunction with posttransplant outcomes.

METHODS

We studied a cohort of 11,488 candidates waitlisted in the Organ Procurement and Transplantation Network (OPTN) for pediatric kidney transplant between 2002 and 2014, including both deceased- and living-donor transplants; 8757 (76 %) candidates received a transplant. Candidates were divided into four groups according to the average volume of yearly transplants performed in the listing center over a 12-year period: more than ten, six to nine, three to five, and fewer than three. We used multivariate Cox regression analysis to identify independent risk factors for wait list and posttransplant mortality.

RESULTS

Twenty-seven percent of candidates were listed at low-volume centers in which fewer than three transplants were performed annually. These candidates had a limited transplant rate; only 49 % received a transplant versus 88 % in high-volume centers (more than ten transplants annually) (p < 0.001). Being listed at a low-volume center showed a fourfold increased risk for death while on the wait list [hazard ratio (HR) 4.0 in multivariate Cox regression and 6.1 in multivariate competing risk regression]. It was not a significant risk factor for posttransplant death in multivariate Cox regression.

CONCLUSIONS

Pediatric transplant candidates are listed at low-volume transplant centers are transplanted less frequently and have a much greater risk of dying while on the wait list. Further studies are needed to elucidate the reasons behind the significant outcome differences.

Increased pediatric sub-specialization is associated with decreased surgical complication rates for inpatient pediatric urology procedures

INTRODUCTION

Increased case volumes and training are associated with better surgical outcomes. However, the impact of pediatric urology sub-specialization on perioperative complication rates is unknown.

OBJECTIVES

To determine the presence and magnitude of difference in rates of common postoperative complications for elective pediatric urology procedures between specialization levels of urologic surgeons. The Nationwide Inpatient Sample (NIS), a nationally representative administrative database, was used.

STUDY DESIGN

The NIS (1998-2009) was retrospectively reviewed for pediatric (≤18 years) admissions, using ICD-9-CM codes to identify urologic surgeries and National Surgical Quality Improvement Program (NSQIP) inpatient postoperative complications. Degree of pediatric sub-specialization was calculated using a Pediatric Proportion Index (PPI), defined as the ratio of children to total patients operated on by each provider. The providers were grouped into PPI quartiles: Q1, 0-25% specialization; Q2, 25-50%; Q3, 50-75%; Q4, 75-100%. Weighted multivariate analysis was performed to test for associations between PPI and surgical complications.

RESULTS

A total of 71,479 weighted inpatient admissions were identified. Patient age decreased with increasing specialization: Q1, 7.9 vs Q2, 4.8 vs Q3, 4.8 vs Q4, 4.6 years, P < 0.01). Specialization was not associated with race (P > 0.20), gender (P > 0.50), or comorbidity scores (P = 0.10). Mortality (1.5% vs 0.2% vs 0.3% vs 0.4%, P < 0.01) and complication rates (15.5% vs 11.7% vs 9.6% vs 10.9%, P < 0.0001) both decreased with increasing specialization. Patients treated by more highly specialized surgeons incurred slightly higher costs (Q2, +4%; Q3, +1%; Q4 + 2%) but experienced shorter length of hospital stay (Q2, -5%; Q3, -10%; Q4, -3%) compared with the least specialized providers. A greater proportion of patients treated by Q1 and Q3 specialized urologists had CCS ≥2 than those seen by Q2 or Q4 urologists (12.5% and 12.2%, respectively vs 8.4% and 10.9%, respectively, P = 0.04). Adjusting for confounding effects, increased pediatric specialization was associated with decreased postoperative complications: Q2 OR 0.78, CI 0.58-1.05; Q3 OR 0.60, CI 0.44-0.84; Q4 OR 0.70, CI 0.58-0.84; P < 0.01.

DISCUSSION

Providers with proportionally higher volumes of pediatric patients achieved better postoperative outcomes than their less sub-specialized counterparts. This may have arisen from increased exposure to pediatric anatomy and physiology, and greater familiarity with pediatric techniques.

LIMITATION

The NIS admission-based retrospective design did not enable assessment of long-term outcomes, repeated admissions, or to track a particular patient across time. The study was similarly limited in evaluating the effect of pre-surgical referral patterns on patient distributions.

CONCLUSIONS

Increased pediatric sub-specialization among urologists was associated with a decreased risk of mortality and surgical complications in children undergoing inpatient urologic procedures.

Results of pediatric living donor compared to deceased donor liver transplantation in the PELD/MELD era: Experience from two centers on two different continents

The LDLT option in the pediatric population allows recipients to be transplanted early. A total of 202 consecutive pediatric liver transplants from two different institutions--108 (LDLT) and 94 (DDLT)--were retrospectively compared. Overall, one- and three-yr patient and graft survival were similar between DDLT and LDLT. ACR was greater in recipients of DDLT at one and three yr (50.8% and 61.0%) compared to LDLT (30.8% and 32.2%) (p = 0.002). When the data were stratified according to PELD/MELD score, LDLT with a low score had better one- and three-yr graft survival (96.2% and 96.2%) compared to DDLT (88.2% and 85.2%) (p = 0.02), with comparable patient survival (p = 0.75). Patient and graft survival were similar between DDLT and LDLT in the high PELD/MELD group. Lower incidence of ACR in both low and high PELD/MELD groups was (29.6% and 34.3%) for LDLT compared to DDLT (50.3% and 53.3%, p = 0.002 and p = 0.028, respectively). Regardless of PELD/MELD score, status, age group, and recipient weight, LDLT provides excellent patient and graft survival with a lower incidence of rejection compared to DDLT.

Disparities in Adherence to Pediatric Sepsis Guidelines across a Spectrum of Emergency Departments: A Multicenter, Cross-Sectional Observational In Situ Simulation Study

BACKGROUND

Each year in the United States, 72,000 pediatric patients develop septic shock, at a cost of $4.8 billion. Adherence to practice guidelines can significantly reduce mortality; however, few methods to compare performance across a spectrum of emergency departments (EDs) have been described.

OBJECTIVES

We employed standardized, in situ simulations to measure and compare adherence to pediatric sepsis guidelines across a spectrum of EDs. We hypothesized that pediatric EDs (PEDs) would have greater adherence to the guidelines than general EDs (GEDs). We also explored factors associated with improved performance.

METHODS

This multi-center observational study examined in situ teams caring for a simulated infant in septic shock. The primary outcome was overall adherence to the pediatric sepsis guideline as measured by six subcomponent metrics. Characteristics of teams were compared using multivariable logistic regression to describe factors associated with improved performance.

RESULTS

We enrolled 47 interprofessional teams from 24 EDs. Overall, 21/47 teams adhered to all six sepsis metrics (45%). PEDs adhered to all six metrics more than GEDs (93% vs. 22%; difference 71%, 95% confidence interval [CI] 43-84). Adherent teams had significantly higher Emergency Medical Services for Children readiness scores, MD composition of physicians to total team members, teamwork scores, provider perceptions of pediatric preparedness, and provider perceptions of sepsis preparedness. In a multivariable regression model, only greater composite team experience had greater adjusted odds of achieving an adherent sepsis score (adjusted odds ratio 1.38, 95% CI 1.01-1.88).

CONCLUSIONS

Using standardized in situ scenarios, we revealed high variability in adherence to the pediatric sepsis guideline across a spectrum of EDs. PEDs demonstrated greater adherence to the guideline than GEDs; however, in adjusted analysis, only composite team experience level of the providers was associated with improved guideline adherence.

Pediatric Liver Transplant Center Volume and the Likelihood of Transplantation

BACKGROUND

Low case volume has been associated with poorer surgical outcomes in a multitude of surgical procedures. We studied the association among low case volume, outcomes, and the likelihood of pediatric liver transplantation.

METHODS

We studied a cohort of 6628 candidates listed in the Organ Procurement and Transplantation Network for primary pediatric liver transplantation between 2002 and 2012; 4532 of the candidates went on to transplantation. Candidates were divided into groups according to the average volume of yearly transplants performed in the listing center over 10 years: >15, 10 to 15, 5 to 9, and <5. We used univariate and multivariate Cox regression analyses with bootstrapping on transplant recipient data and identified independent recipient and donor risk factors for wait-list and posttransplant mortality.

RESULTS

38.5% of the candidates were listed in low-volume centers, those in which <5 transplants were performed annually. These candidates had severely reduced likelihood of transplantation with only 41% receiving a transplant. For the remaining candidates, listed at higher volume centers, the transplant rate was 85% (P < .001). Being listed at a low-volume center was a significant risk factor in multivariate Cox regression analysis for both wait-list mortality (hazard ratio, 3.27; confidence interval, 2.53-4.23) and posttransplant mortality (hazard ratio, 2.21; confidence interval, 1.43-3.40).

CONCLUSIONS

38.5% of pediatric transplant candidates are listed in low-volume transplant centers and have lower likelihood of transplantation and poorer outcomes. If further studies substantiated these findings, we would advocate consolidating pediatric liver transplantation in higher volume centers.

Hospital Surgical Volume and Associated Postoperative Complications of Pediatric Urological Surgery in the United States

PURPOSE

Hospital and provider surgical volume have been increasingly linked to surgical outcomes. However, this topic has rarely been addressed in children. We investigated whether hospital surgical volume impacts complication rates in pediatric urology.

MATERIALS AND METHODS

We retrospectively reviewed the Nationwide Inpatient Sample (1998 to 2011) for pediatric (18 years or younger) hospitalizations for urological procedures. We used ICD-9-CM codes to identify elective urological interventions and NSQIP® postoperative in hospital complications. Annual hospital surgical volume was calculated and dichotomized as high volume (90th percentile or above) or non-high volume (below 90th percentile).

RESULTS

We identified 158,805 urological admissions (114,634 high volume and 44,171 non-high volume hospitals). Of the hospitals 75% recorded fewer than 5 major pediatric urology cases performed yearly. High volume hospitals showed treatment of significantly younger patients (mean 5.4 vs 9.6 years, p < 0.001) and were more likely to be teaching hospitals (93% vs 71%, p < 0.001). The overall rate of NSQIP identified postoperative complications was higher at non-high volume vs high volume hospitals (11.6% vs 9.3%, p = 0.003). After adjusting for confounding effects patients treated at non-high volume hospitals remained more likely to suffer multiple NSQIP tracked postoperative complications, including acute renal failure (OR 1.4, p = 0.04), urinary tract infection (OR 1.3, p = 0.01), postoperative respiratory complications (OR 1.5, p = 0.01), systemic sepsis (OR 2.0, p ≤ 0.001), postoperative bleeding (OR 2.5, p < 0.001) and in hospital death (OR 2.2, p = 0.007).

CONCLUSIONS

Urological procedures performed in children at non-high volume hospitals were associated with an increased risk of in hospital, NSQIP identified postoperative complications, including a small but significant increase in postoperative mortality, mostly following nephrectomy and percutaneous nephrolithotomy.

Association of center volume with outcomes in critically ill children with acute asthma

BACKGROUND

Little is known about the relation between center volume and outcomes in children requiring intensive care unit (ICU) admission for acute asthma.

OBJECTIVE

To evaluate the association of center volume with the odds of receiving positive pressure ventilation and length of ICU stay.

METHODS

Patients 2 to 18 years of age with the primary diagnosis of asthma were included (2009-2012). Center volume was defined as the average number of mechanical ventilator cases per year for any diagnoses during the study period. In multivariable analysis, the odds of receiving positive pressure ventilation (invasive and noninvasive ventilation) and ICU length of stay were evaluated as a function of center volume.

RESULTS

Fifteen thousand eighty-three patients from 103 pediatric ICUs with the primary diagnosis of acute asthma met the inclusion criteria. Seven hundred fifty-two patients (5%) received conventional mechanical ventilation and 964 patients (6%) received noninvasive ventilation. In multivariable analysis, center volume was not associated with the odds of receiving any form of positive pressure ventilation in children with acute asthma, with the exception of high- to medium-volume centers. However, ICU length of stay varied with center volume and was noted to be longer in low-volume centers compared with medium- and high-volume centers.

CONCLUSION

In children with acute asthma, this study establishes a relation between center volume and ICU length of stay. However, this study fails to show any significant relation between center volume and the odds of receiving positive pressure ventilation; further analyses are needed to evaluate this relation in more detail.

Morbidity and mortality associated with liver resections for primary malignancies in children

PURPOSE

Liver resection (LR) is a high-risk procedure with limited data in the pediatric surgical literature regarding short-term outcomes. Our aim was to characterize the patient population and short-term outcomes for children undergoing LR for malignancy.

METHODS

We studied 126 inpatient admissions for children ≤20 years of age undergoing LR in 2009 using the Kids' Inpatient Database. Patients had a principal diagnosis of a primary hepatic malignancy and LR listed as one of the first five procedures. Transplantations were excluded. Complications were defined by ICD-9 codes. High-volume centers performed at least 5 LR.

RESULTS

The mean age was 5.83 years. The morbidity and mortality rates were 30.7 and 3.7%, respectively. The most common causes of morbidity were digestive system complications (7.4%), anemia (7.3%), and respiratory complications (3.8%). 43.9% received a blood product transfusion. The average length of stay was 10.04 days. When compared to low-volume centers, high-volume centers increased the likelihood of a complication fourfold (P = 0.011) but had 0% mortality (P = 0.089).

CONCLUSION

LR remains a procedure fraught with multiple complications and a significant mortality rate. High-volume centers have a fourfold increase in likelihood of complications compared to low-volume centers and may be related to extent of hepatic resection.

Liver Transplant Center Performance Profiling: 2005–2011 Reports of the Scientific Registry for Transplant Recipients

Context

Transplant center performance profiling provides important information for various concerned parties. Comparing a transplant center's performance against the performance of the best-in-class centers may help in understanding the performance thresholds for the underperforming centers.

Objectives

(1) To identify and describe “Centers for Medicare and Medicaid Services (CMS)-red-flag” performers and the “best-in-class” performers and (2) to examine the relationships between a center's performance profile and outcomes such as 1-year observed mortality, 1-month observed mortality, 1-year risk-adjusted mortality, and volume.

Methods

The data for analysis was obtained from the published reports on the Scientific Registry for Transplant Recipients (SRTR) website for adult liver transplant programs compiled for the rolling 2½-year cohorts of patients and included 7 cohorts of liver transplant recipients in the study from January through July 1, 2002, through December 31, 2010. We defined 4 performance profiles: CMS-red-flag, lower-than-expected, higher-than-expected, and best-in-class performers.

Results

The current SRTR methods classify approximately 7% of the adult liver centers as CMS-red-flag performers and 6% of the centers as best-in-class performers in every reported period. Neither of the low-volume centers (<30 liver transplants per 2½-year cohort) was profiled as CMS-red-flag until the 2010 reporting period. The transplant center's profile was significantly associated with the 1-year and 1-month observed mortality rates in every reported cohort ( P < .001).

Conclusion

The CMS-red-flag profile can be characterized with the following: (1) the highest observed 1-year mortality, (2) the highest observed 1-month mortality, (3) a very large difference between the observed and adjusted mortality rates, and (4) the center volume greater than 30 liver transplants per 2½-year cohort. The SRTR methods are not sensitive for performance profiling in the centers that perform fewer than 30 orthotopic liver transplants per 2½-year cohort.

Liver transplantation for children with biliary atresia in the pediatric end-stage liver disease era: the role of insurance status

Socioeconomic status influences health outcomes, although its impact on liver transplantation (LT) in children with biliary atresia (BA) is unknown. We hypothesized that governmental insurance [public insurance (PU)], rather than private insurance (PR), would be associated with poorer outcomes for children with BA. Children with BA who underwent first isolated LT between January 2003 and June 2011 were identified from United Network for Organ Sharing Standard Transplant Analysis and Research files. We identified 757 patients with PR and 761 patients with PU. The race/ethnicity distribution was significantly different between the groups (65% white, 12% black, and 10% Hispanic in the PR group and 33% white, 26% black, and 29% Hispanic in the PU group, P < 0.01). Wait-list mortality was higher for the PU group versus the PR group [46/1654 (2.7%) versus 29/1895 (1.5%), P < 0.01]. PR patients were older than PU patients at transplant (2.4 ± 4.5 versus 1.5 ± 3.0 years, P < 0.01). The donor types differed between the groups: 165 children (21.8%) in the PR group received living donor grafts, whereas 79 children (10.4%) in the PU group did (P < 0.01). The 1- and 5-year posttransplant patient survival rates were greater for the PR group versus the PU group (98.0% versus 94.1% at 1 year, P < 0.01; 97.8% versus 92.2% at 5 years, P < 0.01). Cox proportional hazards models revealed that the insurance type (PU), the donor type (deceased), and life support were significant risk factors for death. A separate analysis of deceased donor LT revealed that the PU group still had significantly worse patient and graft survival. In conclusion, PU coverage is an independent risk factor for significantly increased wait-list and posttransplant mortality in children with BA. Further studies are needed to unearth the reasons for these important differences in outcomes.

Relationship between pediatric blood and marrow transplant center volume and day +100 mortality: Pediatric Blood and Marrow Transplant Consortium experience

The number of patients receiving a BMT is currently being used as a factor in the accreditation process in determining whether a center can provide a high-quality BMT. Such criteria particularly impact pediatric BMT centers as most of them perform a relatively small number of BMTs. To determine whether patient volume is a valid marker of pediatric BMT center's capabilities, the Pediatric Blood and Marrow Transplant Consortium (PBMTC) evaluated data from its registry to define the relationship between a pediatric transplant center's patient volume and day +100 mortality. The analyses evaluated 2575 transplants from 60 centers reporting to the PBMTC between the years 2002 and 2004. The volume-outcome relationship was evaluated while adjusting for 46 independent data categories divided between nine variables that were known- or suspected-mortality risk factors. We found no association between transplant center volume and day +100 mortality in several analyses. A calculated intraclass correlation coefficient also indicated that differences in individual transplant center volume contributed to only 1% of the variance in day +100 mortality within the PBMTC. The results of this study suggest that factors other than transplant center volume contribute to variation in day +100 mortality among pediatric patients.

Association of center volume with mortality and complications in pediatric heart surgery

OBJECTIVE

Previous analyses have suggested center volume is associated with outcome in children undergoing heart surgery. However, data are limited regarding potential mediating factors, including the relationship of center volume with postoperative complications and mortality in those who suffer a complication. We examined this association in a large multicenter cohort.

METHODS

Children 0 to 18 years undergoing heart surgery at centers participating in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2006-2009) were included. In multivariable analysis, we evaluated outcomes associated with annual center volume, adjusting for patient factors and surgical risk category.

RESULTS

A total of 35 776 patients (68 centers) were included. Overall, 40.6% of patients had ≥1 complication, and the in-hospital mortality rate was 3.9%. The mortality rate in those patients with a complication was 9.0%. In multivariable analysis, lower center volume was significantly associated with higher in-hospital mortality. There was no association of center volume with the rate of postoperative complications, but lower center volume was significantly associated with higher mortality in those with a complication (P = .03 when volume examined as a continuous variable; odds ratio in centers with <150 vs >350 cases per year = 1.59 [95% confidence interval: 1.16-2.18]). This association was most prominent in the higher surgical risk categories.

CONCLUSIONS

These data suggest that the higher mortality observed at lower volume centers in children undergoing heart surgery may be related to a higher rate of mortality in those with postoperative complications, rather than a higher rate of complications alone.

Impact of center volume on outcomes of increased-risk liver transplants

The use of high-risk donor livers, which is reflective of the gross national shortage of organs available for transplantation, has gained momentum. Despite the demand, many marginal livers are discarded annually. We evaluated the impact of center volume on survival outcomes associated with liver transplantation using high-donor risk index (DRI) allografts. We queried the Scientific Registry of Transplant Recipients database for deceased donor liver transplants (n = 31,576) performed between 2002 and 2008 for patients who were 18 years old or older, and we excluded partial and multiple liver transplants. A high-DRI cohort (n = 15,668), which was composed of patients receiving grafts with DRIs > 1.90, was analyzed separately. Transplant centers (n = 102) were categorized into tertiles by their annual procedure volumes: high-volume centers (HVCs; 78-215 cases per year), medium-volume centers (MVCs; 49-77 cases per year), and low-volume centers (LVCs; 5-48 cases per year). The endpoints were allograft survival and recipient survival. In comparison with their lower volume counterparts, HVCs used donors with higher mean DRIs (2.07 for HVCs, 2.01 for MVCs, and 1.91 for LVCs), more donors who were 60 years old or older (18.02% for HVCs, 16.85% for MVCs, and 12.39% for LVCs), more donors who died after a stroke (46.52% for HVCs, 43.71% for MVCs, and 43.36% for LVCs), and more donation after cardiac death organs (5.04% for HVCs, 4.45% for MVCs, and 3.51% for LVCs, all P values < 0.001). Multivariate risk-adjusted frailty models showed that increased procedure volume at a transplant center led to decreased risks of allograft failure [hazard ratio (HR) = 0.93, 95% confidence interval (CI) = 0.89-0.98, P = 0.002] and recipient death (HR = 0.90, 95% CI = 0.83-0.97, P = 0.004) for high-DRI liver transplants. In conclusion, HVCs more frequently used higher DRI livers and achieved better risk-adjusted allograft and recipient survival. A greater understanding of the outcomes of transplantation with high-DRI livers may improve their utilization, the postoperative outcomes, and future allocation practices.

A multivariate analysis of pre-, peri-, and post-transplant factors affecting outcome after pediatric liver transplantation

OBJECTIVE

The purpose of this study was to identify significant, independent factors that predicted 6 month patient and graft survival after pediatric liver transplantation.

SUMMARY BACKGROUND DATA

The Studies of Pediatric Liver Transplantation (SPLIT) is a multicenter database established in 1995, of currently more than 4000 US and Canadian children undergoing liver transplantation. Previous published analyses from this data have examined specific factors influencing outcome. This study analyzes a comprehensive range of factors that may influence outcome from the time of listing through the peri- and postoperative period.

METHODS

A total of 42 pre-, peri- and posttransplant variables evaluated in 2982 pediatric recipients of a first liver transplant registered in SPLIT significant at the univariate level were included in multivariate models.

RESULTS

In the final model combining all baseline and posttransplant events, posttransplant complications had the highest relative risk of death or graft loss. Reoperation for any cause increased the risk for both patient and graft loss by 11 fold and reoperation exclusive of specific complications by 4 fold. Vascular thromboses, bowel perforation, septicemia, and retransplantation, each independently increased the risk of patient and graft loss by 3 to 4 fold. The only baseline factor with a similarly high relative risk for patient and graft loss was recipient in the intensive care unit (ICU) intubated at transplant. A significant center effect was also found but did not change the impact of the highly significant factors already identified.

CONCLUSIONS

We conclude that the most significant factors predicting patient and graft loss at 6 months in children listed for transplant are posttransplant surgical complications.

Impact of hospital volume on in-hospital mortality of infants undergoing repair of congenital diaphragmatic hernia

OBJECTIVES

Congenital diaphragmatic hernia (CDH) remains a significant cause of neonatal morbidity and mortality.

SUMMARY OF BACKGROUND DATA

Previous studies have suggested that hospital volume is an independent predictor of in-hospital mortality. We sought to validate this effect using a large national database incorporating 37 free-standing children's hospitals in the United States.

METHODS

Infants who underwent repair of CDH from 2000 to 2008 at Pediatric Health Information Systems-member hospitals were evaluated. Hospitals were categorized by tertiles into low-volume (≤6 cases/yr), medium-volume (6-10 cases/yr), and high-volume (>10 cases/yr). Using generalized linear mixed models with random effects, we computed the risk-adjusted odds ratio of mortality by yearly hospital volume of CDH repair, after adjustment for salient patient and hospital characteristics.

RESULTS

There were 2203 infants who underwent repair with an overall survival of 82%. Average yearly hospital volume of CDH repair varied from 1.4 to 17.5 cases per year. Smaller birthweight (adjusted odds ratio [aOR]: 0.56 per kg, P < 0.001), year of birth (P < 0.001), chromosomal abnormalities (aOR: 3.83, P < 0.01), longer time to repair (aOR: 1.12 per week, P < 0.05), the thoracic approach for repair (P < 0.02), and requirement for extracorporeal membrane oxygenation (aOR: 10.31, P < 0.0001), or inhaled nitric oxide (aOR: 5.25, P < 0.0001) were each independently associated with mortality. Compared with low-volume hospitals, medium-volume (aOR: 0.56, P < 0.05) and high-volume (aOR: 0.44, P < 0.01) hospitals had a significantly lower mortality. The rate of extracorporeal membrane oxygenation use at each facility was not independently associated with mortality.

CONCLUSIONS

This large study suggests that hospitals which perform high volumes of CDH repair achieve lower in-hospital mortality. These data support the paradigm of regionalized centers of excellence for the management of infants with this morbid condition.