The effect of donor graft type on survival after liver transplantation for hepatoblastoma in children

BACKGROUND

Liver transplantation (LT) is the only potentially curative option for children with unresectable hepatoblastoma (HBL). Although post-transplant outcomes have improved in the contemporary era, the impact of donor graft type on survival remains unclear.

METHODS

Using the United Network for Organ Sharing database (02/2002-06/2021), demographics, clinical characteristics, and patient and graft survival were analyzed in children (<18 years) who underwent LT for HBL according to donor graft type. The Kaplan-Meier method, log-rank tests, and Cox regression modeling were used to evaluate the effect of whole, partial, and split deceased donor liver transplantation (DDLT) and living donor liver transplantation (LDLT) on patient and graft survival.

RESULTS

A total of 590 pediatric HBL LT recipients (344 whole graft DDLT; 62 partial graft DDLT; 139 split graft DDLT; 45 LDLT) were included. During 2012-2021 the proportion of LDLTs for HBL decreased to about 5% compared with about 11% during 2002-2011. No significant differences were identified by donor graft type in either patient survival (log-rank test, p = .45) or graft survival (log-rank test, p = .69). The results remained similar during the 2002-2011 era, while during the 2012-2021 era, split graft DDLT was associated with decreased graft loss risk versus whole graft DDLT (hazard ratio: 0.48, 95% confidence interval: 0.23-0.99, p = .046) without any other significant between-group differences.

CONCLUSIONS

Utilizing non-whole liver grafts can increase access to LT in children with unresectable HBL while ensuring favorable outcomes. LDLT is underutilized in children with HBL in the United States, and efforts to explore LDLT options should be undertaken.

Postoperative considerations based on graft type after anterior cruciate ligament reconstruction a narrative review

Background and Objective

Graft selection for anterior cruciate ligament reconstruction (ACLR) affects rehabilitation throughout the course of postoperative care.

Methods

A search of PubMed and EBSCO was performed and abstracts independently reviewed by two authors. This search was also supplemented with additional evidence relevant to each phase of ACLR rehabilitation.

Key Content and Findings

Direct implications of graft type on clinical decisions vary throughout treatment phases, transitioning from potential differences in acute postoperative pain management immediately after surgery to facilitating sufficient and appropriate lower extremity loading in subsequent weeks. Regardless of graft type, surgical limb weakness persists throughout the course of rehabilitation; however, harvest site selection for autografts contributes to disproportionate weakness of the harvested muscle group and the potential for surgical-induced tendinopathy. In later phases of rehabilitation, as athletes are transitioning into return to sport (RTS), treatment decisions and protocols are less affected by graft type but expectations for meeting clinical milestones and the time required to do so does differ between graft types.

Conclusions

Targeted strengthening interventions to address muscle weakness following graft harvest in autografts should be continued throughout the rehabilitation process. Lingering deficits in quadriceps strength symmetry may also influence time to meet progression and RTS criteria following graft harvest from the extensor mechanism.

Reassessing Geographic, Logistical, and Cold Ischemia Cutoffs in Liver Transplantation

INTRODUCTION

Liver acceptance patterns vary significantly between transplant centers. Data pertaining to outcomes of livers declined by local and regional centers and allocated nationally remains limited.

PROJECT AIM

The objective was to compare post-liver transplant outcomes between liver allografts transplanted as a result of national and local-regional allocation.

DESIGN

This was a retrospective evaluation of 109 nationally allocated liver allografts used for transplant by a single center. Outcomes of nationally allocated grafts were compared to standard allocation grafts (N  =  505) during the same period.

RESULTS

Recipients of nationally allocated grafts had lower model for end stage liver disease scores (17 vs 22, P  =  .001). Nationally allocated grafts were more likely to be post-cross clamp offers (29.4% vs 13.4%, P  =  .001) and have longer cold ischemia times (median hours 7.8 vs 5.5, P  =  .001). Early allograft dysfunction was common (54.1% vs 52.5%, P  =  .75) and did not impact hospital length of stay (median 5 vs 6 days, P  =  .89). There were no differences in biliary complications (P  =  .11). There were no differences in patient (P  =  .88) or graft survival (P  =  .35). In a multivariate model, after accounting for differences in cold ischemia time and posttransplant biliary complications, nationally allocated grafts were not associated with increased risk for graft loss (HR 0.9, 95% CI 0.4-1.8). Abnormal liver biopsy findings (33.0%) followed by donor donation after circulatory death status (22.9%) were the most common reasons for decline by local-regional centers.

CONCLUSION

Despite longer cold ischemia times, patient and graft survival outcomes remain excellent and comparable to those seen from standard allocation grafts.

Association of DGF and Early Readmissions on Outcomes Following Kidney Transplantation

Concerns regarding outcomes and early resource utilization are potential deterrents to broader use of kidneys at risk for delayed graft function (DGF). We assessed outcomes specific to kidneys with DGF that required early readmission following transplant. Three groups were identified: 1) recipients with DGF not requiring readmission, 2) recipients with DGF having an isolated readmission, and 3) recipients with DGF requiring ≥2 readmissions. Most recipients either required a single readmission (26.8%, n = 247) or no readmission (56.1%, n = 517); 17.1% (n = 158), had ≥2 readmissions. Recipients requiring ≥2 readmissions were likely to be diabetic (53.8%, p = 0.04) and have longer dialysis vintage (p = 0.01). Duration of DGF was longer with increasing number of readmissions (p < 0.001). There were no differences in patient survival for those with DGF and 0, 1 and ≥2 readmissions (p = 0.13). Graft survival, however, was lower for those with ≥2 readmissions (p < 0.0001). This remained true when accounting for death-censored graft loss (p = 0.0012). Additional subgroup analysis was performed on mate kidneys with and without DGF and mate kidneys, both with DGF, with and without readmissions. For these subgroups, there were no differences in patient or graft survival. As a whole, patients with DGF have excellent outcomes, however, patients with DGF requiring ≥2 readmissions have lower graft survival. A better understanding of recipient variables contributing to multiple readmissions may allow for improvements in the utilization of DGF at-risk kidneys.

Bone-Patellar Tendon-Bone Autograft Harvest Prolongs Extensor Latency during Gait 2 yr after ACLR

PURPOSE

Bone-patellar tendon-bone (BPTB) graft harvest for anterior cruciate ligament reconstruction alters patellar tendon properties, which inflict poor quadriceps neuromuscular function. BPTB autografts are associated with higher rates of posttraumatic osteoarthritis, which in turn is associated with pathological gait. The purpose of this study was to investigate the latency between the time of peak quadriceps activity and the peak knee flexion moment during gait, between those with BPTB grafts ( n = 23) and other graft types (hamstring autograft or allografts, n = 54), 5 ± 2 months and 2 yr (25 ± 3 months) after anterior cruciate ligament reconstruction. We hypothesized that longer latencies would be observed in the BPTB graft group in the involved limb. We expected latencies to shorten over time.

METHODS

Knee moments and quadriceps EMG were collected during gait, and vastus medialis, vastus lateralis, rectus femoris (RF), and quadriceps latencies were calculated. Linear mixed-effects models were used to compare latencies between graft types and over the two time points.

RESULTS

The main effects of graft type were observed for vastus medialis ( P = 0.005) and quadriceps ( P = 0.033) latencies with the BPTB graft group demonstrating longer latencies. No main effects of graft type were observed for vastus lateralis ( P = 0.051) and RF ( P = 0.080) latencies. Main effects of time were observed for RF latency ( P = 0.022).

CONCLUSIONS

Our hypothesis that the BPTB graft group would demonstrate longer extensor latency was supported. Contrary to our second hypothesis, however, latency only improved in RF and regardless of graft type, indicating that neuromuscular deficits associated with BPTB grafts may persist 2 yr after surgery. Persistent deficits may be mediated by changes in the patellar tendon's mechanical properties. Graft-specific rehabilitation may be warranted to address the long-term neuromechanical deficits that are present after BPTB graft harvest.

Impact of allograft types on outcomes after pediatric liver transplantation due to biliary atresia

BACKGROUND

Several surgical strategies, including split donor transplantation and living donor transplantation, have been used to increase the donor liver pool. This report focuses on the effects of whole, split, and LDLT on recipient outcomes.

METHODS

We retrospectively analyzed the records of all patients with biliary atresia at Tianjin First Central Hospital between April 2013 and December 2019.

RESULTS

A total of 882 patients were included and divided into three groups by graft type, with 198 in the whole-liver-transplantation group, 78 in the split liver transplantation group, and 606 in the LDLT group. The median follow-up time was 39 months, patient survival rates of three groups were 94.4%, 88.5%, and 95.0%, respectively, and graft survival rates were 90.2%, 83.3%, and 94.7%, respectively. We divided the split liver transplantation group into two subgroups according to the donor's age, and patient survival rates exhibited a significant difference only in the group whose donor age was over 45 years. The postoperative complication rates were significantly higher with respect to hepatic artery thrombosis, portal stenosis, and AR; and lower in hepatic venous stenosis, PTLDs, CMV virus, and EBV infection in the WLT group. Our multivariate model showed that donor age ≥45 years, RBC transfusion, pneumonia, and HAT were the independent predictors of allograft loss.

CONCLUSIONS

The survival of split liver transplantation group was slightly lower. The types of complications are different from different graft types. Therefore, postoperative monitoring and treatment need to be adjusted according to the different graft types used.

Decreasing Significance of Early Allograft Dysfunction with Rising Use of Nonconventional Donors

Background and Objectives: Early allograft dysfunction (EAD) is considered a surrogate marker for adverse post-liver transplant (LT) outcomes. With the increasing use of nonconventional donors, EAD has become a more frequent occurrence. Given this background, we aimed to assess the prevalence and impact of EAD in an updated cohort inclusive of both conventional and nonconventional liver allografts. Materials and Methods: Perioperative and one-year outcomes were assessed for a total of 611 LT recipients with and without EAD from Mayo Clinic Arizona. EAD was defined as the presence of one or more of the following: bilirubin > 10 mg/dL on day 7, INR > 1.6 on day 7, or ALT and/or AST > 2000 IU/L within the first 7 days of LT. Results: Within this cohort, 31.8% of grafts (n = 194) came from donation after circulatory death (DCD) donors, 17.7% (n = 108) were nationally shared, 16.4% (n = 100) were allocated as post-cross clamp, and 8.7% contained moderate steatosis. EAD was observed in 52.2% (n = 321) of grafts in the study cohort (79% in DCD grafts and 40% in DBD grafts). EAD grafts had higher donor risk index (DRI) scores (1.9 vs. 1.6, p < 0.0001), were more likely to come from DCD donors (48% vs. 13.8%, p < 0.0001), were regionally allocated (p = 0.003), and had higher cold ischemia times (median 6.0 vs. 5.5 h, p = 0.001). Primary nonfunction events were rare in both groups (1.3% vs. 0.3%, p = 0.22). Post-LT acute kidney injury occurred at a similar frequency in recipients with and without EAD (43.6% vs. 30.3%, p = 0.41), and there were no differences in ICU (median 2 vs. 1 day, p = 0.60) or hospital (6 vs. 5 days, p = 0.24) length of stay. For DCD grafts, the rate of ischemic cholangiopathy was similar in the two groups (14.9% EAD vs. 17.5% no EAD, p = 0.69). One-year patient survival for grafts with and without EAD was 96.0% and 94.1% (HR 1.2, 95% CI 0.7−1.8; p = 0.54); one-year graft survival was 92.5% and 92.1% (HR 1.0, 95% CI 0.7−1.5; p = 0.88). Conclusions: In this cohort, EAD occurred in 52% of grafts. The occurrence of EAD, however, did not portend inferior outcomes. Compared to those without EAD, recipients with EAD had similar post-operative outcomes, as well as one-year patient and graft survival. EAD should be managed supportively and should not be viewed as a deterrent to utilization of non-ideal grafts.

Outcomes of Dual Kidney Transplants from High KDPI Kidneys are Superior Compared to Single Kidney High KDPI Transplants at One-Year

Dual kidney transplantation (DKT), utilizing two adult kidneys from the same donor for one recipient, has been used as way to expand the available donor pool. These kidneys often come from high Kidney Donor Profile Index donors (KDPI >85%). Data comparing outcomes between high KDPI DKT and single kidney transplants (SKT) remain limited. We assessed outcomes of 336 high KDPI kidney transplants performed at our center; 11.0% (n = 37) were DKT. Recipients of DKT were older (p = 0.02) and donors had a higher KDPI score (median 96% vs. 91%, p<0.0001). DKT operative time was higher compared to SKT (+1.4 hours, p<0.0001). There were no differences in delayed graft function (54.1% vs. 51.5%, p = 0.77) and hospital length of stay (median 4.0 vs. 3.0 days, p = 0.21) between DKT and SKT. Grade I Clavien-Dindo complications occurred in 8.1% of DKT and 13.7% of SKT (p = 0.008). There were no grade IVa, IVb or V complications in either group. DKT had more glomerulosclerosis (p = 0.04), interstitial fibrosis (p = 0.02), tubular atrophy (p = 0.01), and arterial thickening (p = 0.03) on one-year protocol biopsies. Estimated glomerular filtration was higher for DKT at one- (p = 0.004) and two-years post-transplant (p = 0.01). There were no differences in patient (HR 1.3, 95% CI 0.5-3.3, p = 0.58) or graft (HR 1.1, 95% CI 0.5-2.3, p = 0.83) survival. Good outcomes can be achieved with DKT using high KDPI kidneys with moderate chronic changes. DKT is a good option to help further utilize high KDPI kidneys and minimize discard. This article is protected by copyright. All rights reserved.

A Review on Finite Element Modeling and Simulation of the Anterior Cruciate Ligament Reconstruction

The anterior cruciate ligament (ACL) constitutes one of the most important stabilizing tissues of the knee joint whose rapture is very prevalent. ACL reconstruction (ACLR) from a graft is a surgery which yields the best outcome. Taking into account the complicated nature of this operation and the high cost of experiments, finite element (FE) simulations can become a valuable tool for evaluating the surgery in a pre-clinical setting. The present study summarizes, for the first time, the current advancement in ACLR in both clinical and computational level. It also emphasizes on the material modeling and properties of the most popular grafts as well as modeling of different surgery techniques. It can be concluded that more effort is needed to be put toward more realistic simulation of the surgery, including also the use of two bundles for graft representation, graft pretension and artificial grafts. Furthermore, muscles and synovial fluid need to be included, while patellofemoral joint is an important bone that is rarely used. More realistic models are also required for soft tissues, as most articles used isotropic linear elastic models and springs. In summary, accurate and realistic FE analysis in conjunction with multidisciplinary collaboration could contribute to ACLR improvement provided that several important aspects are carefully considered.

Performance and Return to Sport After Anterior Cruciate Ligament Reconstruction in Professional Baseball Players

Background:

Anterior cruciate ligament reconstruction (ACLR) is the gold standard treatment for ACL tears to allow baseball players to return to sport (RTS). The optimal graft type and femoral tunnel drilling technique are currently unknown.

Hypothesis:

There is a high rate of RTS in professional baseball players after ACLR, with no significant difference in RTS rates or performance between cases and controls or between graft types or femoral drilling techniques.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

All professional baseball players who underwent ACLR between 2010 and 2015 were included. Demographic and performance data (pre- and postoperative) for each player were recorded. Performance metrics were then compared between cases and matched controls.

Results:

A total of 124 players (mean age, 23.7 ± 4.1 years; 83% minor league players) underwent ACLR. Of these, 80% returned to sport (73% to the same or higher level) at a mean 310 ± 109 days overall and 333 ± 126 days at the same or higher level. The most common graft type was an ipsilateral bone–patellar tendon–bone (BTB) autograft (n = 87; 70%). A total of 91 players underwent concomitant meniscal debridement or repair. No significant difference in any of the primary performance metrics existed from before to after ACLR. Compared with matched controls, no significant difference existed in RTS rates or any performance metrics after ACLR. No significant difference existed in RTS rates or primary performance outcome measures between graft types or femoral drilling techniques.

Conclusion:

The RTS rate for professional baseball players after ACLR was 80%. No significant difference in performance metrics existed between BTB and hamstring autografts or between femoral drilling techniques. Furthermore, no significant difference in performance or RTS rates existed between cases and matched controls. Femoral drilling technique and graft type did not affect performance and RTS rates in professional baseball players after ACLR.

The Incidence of Subsequent Meniscal Surgery Is Higher in the Anterior Cruciate Ligament-Reconstructed Knee Than in the Contralateral Knee

BACKGROUND

A goal of anterior cruciate ligament (ACL) reconstruction is to provide a meniscal protective effect for the knee.

PURPOSE

(1) To evaluate whether there was a different likelihood of subsequent meniscal surgery in the ACL-reconstructed knee or in the normal contralateral knee and (2) to compare the risk factors associated with subsequent meniscal surgery in the ACL-reconstructed knee and contralateral knee.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Using an integrated health care system's ACL reconstruction registry, patients undergoing primary ACL reconstruction, with no meniscal injury at the time of index surgery and a normal contralateral knee, were evaluated. Subsequent meniscal tears associated with ACL graft revision were excluded. Subsequent meniscal surgery in either knee was the outcome of interest. Sex, age, and graft type were assessed as potential risk factors. Survival analysis was used to compare meniscal surgery-free survival rates and to assess risk factors of subsequent meniscal surgery.

RESULTS

Of 4087 patients, there were 32 (0.78%) patients who underwent subsequent meniscal surgery in the index knee and 9 (0.22%) in the contralateral knee. The meniscal surgery-free survival rate at 4 years was 99.08% (95% CI, 98.64%-99.37%) in the index knee and 99.65% (95% CI, 99.31%-99.82%) in the contralateral knee. There was a 3.73 (95% CI, 1.73-8.04; P < .001) higher risk of subsequent meniscal surgery in the index knee compared with the contralateral knee, or a 0.57% absolute risk difference. After adjustments, allografts (hazard ratio [HR], 5.06; 95% CI, 1.80-14.23; P = .002) and hamstring autografts (HR, 3.11; 95% CI, 1.06-9.10; P = .038) were risk factors for subsequent meniscal surgery in the index knee compared with bone-patellar tendon-bone (BPTB) autografts.

CONCLUSION

After ACL reconstruction, the overall risk of subsequent meniscal surgery was low. However, the relative risk of subsequent meniscal surgery in the ACL-reconstructed knee was higher compared with the contralateral knee. Only graft type was found to be a risk factor for subsequent meniscal surgery in the ACL-reconstructed knee, with a higher risk for allografts and hamstring autografts compared with BPTB autografts.

Infections in anterior cruciate ligament reconstruction

Context:

Anterior cruciate ligament (ACL) reconstruction is a safe, common, and effective method of restoring stability to the knee after injury, but evolving techniques of reconstruction carry inherent risk. Infection after ACL reconstruction, while rare, carries a high morbidity, potentially resulting in a poor clinical outcome.

Evidence Acquisition:

Data were obtained from previously published peer-reviewed literature through a search of the entire PubMed database (up to December 2012) as well as from textbook chapters.

Results:

Treatment with culture-specific antibiotics and debridement with graft retention is recommended as initial treatment, but with persistent infection, consideration should be given to graft removal. Graft type likely has no effect on infection rates.

Conclusion:

The early diagnosis of infection and appropriate treatment are necessary to avoid the complications of articular cartilage damage and arthrofibrosis.

Is left lobe adult-to-adult living donor liver transplantation ready for widespread use? The US experience (1998-2010)

OBJECTIVES

Living donor liver transplantation (LDLT) is an accepted treatment for patients with end-stage liver disease. To minimize risk to the donor, left lobe (LL) LDLT may be an ideal option in adult LDLT.

METHODS

This study assessed the outcomes of LL-LDLT compared with right lobe (RL) LDLT in adults (1998-2010) as reported to the United Network for Organ Sharing (UNOS) Organ Procurement and Transplantation Network (OPTN).

RESULTS

A total of 2844 recipients of LDLT were identified. Of these, 2690 (94.6%) underwent RL-LDLT and 154 (5.4%) underwent LL-LDLT. A recent increase in the number of LL-LDLTs was noted: average numbers of LL-LDLTs per year were 5.2 during 1998-2003 and 19.4 during 2004-2010. Compared with RL-LDLT recipients, LL-LDLT recipients were younger (mean age: 50.5 years vs. 47.0 years), had a lower body mass index (BMI) (mean BMI: 24.5 kg/m(2) vs. 26.8 kg/m(2)), and were more likely to be female (64.6% vs. 41.9%). Donors in LL-LDLT had a higher BMI (mean BMI: 29.4 kg/m(2) vs. 26.5 kg/m(2)) and were less likely to be female (30.9% vs. 48.1%). Recipients of LL-LDLT had a longer mean length of stay (24.9 days vs. 18.2 days) and higher retransplantation rates (20.3% vs. 10.9%). Allograft survival in LL-LDLT was significantly lower than in RL-LDLT and there was a trend towards inferior patient survival. In Cox regression analysis, LL-LDLT was found to be associated with an increased risk for allograft failure [hazard ratio (HR): 2.39)] and inferior patient survival (HR: 1.86).

CONCLUSIONS

The number of LL-LDLTs has increased in recent years.