Changing pattern of organ donation at a single center: are potential brain dead donors being lost to donation after cardiac death?

Assessment of mechanical and biocompatible performance of ultra-large nitinol endovascular devices fabricated via a low-energy laser joining process

Nitinol is an excellent candidate material for developing various self-expanding endovascular devices due to its unique properties such as superelasticity, biocompatibility and shape memory effect. A low-energy laser joining technique suggests a high potential to create various large diameter Nitinol endovascular devices that contain complex geometries. The primary purpose of the study is to investigate the effects of laser joining process parameters with regard to the mechanical and biocompatible performance of Nitinol stents. Both the chemical composition and the microstructure of the laser-welded joints were evaluated using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). In vitro study results on cytotoxicity demonstrated that the joining condition of 8 Hz frequency and 1 kW laser power showed the highest degree of endothelial cell viability after thermal annealing in 500°C for 30 min. Also, in vitro study results showed the highest oxygen content at 0.9 kW laser power, 8 Hz frequency, and 0.3 mm spot size after the thermal annealing. Mechanical performance test results showed that the optimal condition for the highest disconnecting force was found at 1 Hz frequency and 1 kW power with 0.6 mm spot size. Two new endovascular devices have been fabricated using the optimized laser joining parameters, which have demonstrated successful device delivery and retrieval, as well as acute biocompatibility.

Implementation of donation after circulatory death kidney transplantation can safely enlarge the donor pool: A systematic review and meta-analysis

BACKGROUND

Donation after circulatory death (DCD) kidney transplantation has been introduced to address organ shortage. However, DCD kidneys are not accepted worldwide due to concerns about inferior quality. To investigate whether these concerns are justified, we performed a systematic review and meta-analysis to investigate DCD graft outcomes compared to donation after brain death (DBD).

MATERIALS AND METHODS

EMBASE, Medline, Cochrane, Web of Science and Google Scholar were searched from database inception until September 2020. Exclusion criteria were studies reporting on pediatric/dual kidney transplants, multi-organ transplants or studies including normothermic perfusion techniques. The primary outcome was graft survival. Secondary outcomes were primary non-function (PNF), delayed graft function (DGF), 3-months biopsy-proven acute rejection (BPAR), 1-year estimated Glomerular Filtration Rate (eGFR), patient survival, and urologic complications. A random-effects model was used for meta-analysis. Meta-regression analysis was performed in case of high between-study heterogeneity.

RESULTS

Fifty-one studies were included, comprising 73,454 DCD and 518,229 DBD recipients. One-year graft loss was increased in DCD recipients (death-censored: risk ratio (RR) 1.10 (95%-confidence interval (CI) 1.04-1.16), all-cause: RR 1.13 (95%-CI 1.08-1.19)). Ten-year graft loss was similar to DBD (death-censored: RR 1.02 (95%-CI 0.92-1.13), all-cause: RR 1.03 (95%-CI 0.94-1.13)). DCD recipients had an increased risk of PNF (RR 1.43 (95%-CI 1.26-1.62)), DGF (RR 2.02 (95%-CI 1.88-2.16)), and 1-year mortality (RR 1.10 (95%-CI 1.01-1.21)). No differences were observed for 3-months BPAR, ureter stenosis/leakage, 1-year eGFR and 10-year mortality.

CONCLUSION

Long-term DCD kidney transplant outcomes are similar to DBD despite a higher risk of PNF, DGF, and a 13% increased risk of graft loss in the first year after transplantation. These results should encourage implementation of DCD programs.

Changes in Clinical Features and Demographics in Donors After Brain Death Over the Past 20 Years: A Single-Center Experience in the Republic of Korea

OBJECTIVES

We investigated clinical characteristics and demographics of brain death in patients from a single center in Korea to identify possible changes in organ procurement by comparing early and late periods.

MATERIALS AND METHODS

Potential donors diagnosed as brain dead and who had provided organ donation consent from May 2000 to May 2020 were considered. Donors were divided into 2 categories: early period (2000-2010) and late period (2011-2020).Demographic data, clinicalrisk factors, cause of death, use ofinotropic and vasoconstrictor agents, laboratory findings, intensive care unit stay data, loss of donors, and number of donated organs were analyzed.

RESULTS

Mean age of donors significantly increased in the late period (36.0 ± 12.0 vs 46.0 ± 15.1 years), but there were no significant differences in the proportion of females and the number of pediatric donors (<18 years). The number of donors who smoked decreased (61% vs 41%), but hypertension rate increased significantly in the late period (17.4% vs 31.0%). In the late period, fewer brain dead donors were lost (19.0% vs 7.59%) and use of vasoconstrictor agents was more frequent (25.3% vs 64.5%) than use of inotropic agents (73.1% vs 49.3%). In the late period, heart(19.0% vs 37.3%) and lung (0% vs 18.3%) procurement rates increased and the number of transplanted organs per donorincreased (2.58 ± 1.6 vs 3.14 ± 1.50; P = .016). Causes of death were primarily from head traumas (34.4%), cerebral aneurysms (21.7%), spontaneous intracerebral hemorrhage (21.3%), and asphyxia/hanging (16.3%). Head trauma decreased in the late period (46% vs 29.7%; P = .021) but still constituted the most common cause of death.

CONCLUSIONS

We found no definite demographic changes in brain dead donors. Donors with cerebrovascular disease increased annually, but trauma was still the most common cause of brain death, with suicides being highly frequent.

Comparison of pediatric brain-dead donors to donation after circulatory death donors in the United States

In pediatrics, an increasing need for transplantable organs exists. This study aimed to describe the epidemiology of pediatric deceased donors in the United States. This retrospective observational study utilized data from the Organ Procurement and Transplantation Network (OPTN) from 2000 to 2015. Patients were stratified based on method of organ donation. Demographic variables and mechanism of death were then compared. A total of 14,481 deceased pediatric organ donors, donation after brain death (DBD) and donation after circulatory death (DCD), were included in the study, of which 8% were DCD donors. A significant difference (p<0.001) existed between the two donor groups with respect to ethnicity and mechanism of death. The annual trend of DCD and DBD donors showed an inverse relationship. During the 15-year study period the number of DBD donors decreased from 985 to 785 per year while DCD donors increased from 15 to 146 per year. As well, overall organs transplanted per year decreased from 3,475 to 3,117 over the 15-year study period. Significant differences exist between pediatric DBD donors and DCD donors, specifically with respect to ethnicity and mechanism of death. The number of pediatric DBD donors is decreasing while the number of pediatric DCD is slowly rising, making it increasingly important to be able to characterize these donors to better identify eligible DCD donors to optimize organ utilization.

Protein Profiles of Pretransplant Grafts Predict Early Allograft Dysfunction After Liver Transplantation From Donation After Circulatory Death

BACKGROUND

Predicting the development of early allograft dysfunction (EAD) following liver transplantation (LT) remains challenging for transplant clinicians. The objectives of this study are to investigate the potential relationship between the protein profiles of pretransplant grafts and the onset of EAD, and then combine with clinical parameters to construct a mathematically predictive model.

METHODS

Clinical data of 121 LT procedures from donation after circulatory death at the authors' center were analyzed. The expression levels of 7 studied proteins were determined by immunohistochemistry. Another independent cohort of 37 subjects was designed for further validation of the predictive model.

RESULTS

With an incidence of 43.0% (52/121), EAD was linked to significantly increased risk of acute kidney injury and renal replacement therapy, as well as reduced 6-month patient and liver graft survival. Allograft weight and high intrahepatic vascular endothelial growth factor (VEGF) expression were identified as independent risk factors of EAD and survival outcomes. Liver grafts with high VEGF expression exhibited delayed functional recovery within the first postoperative week. The combination of VEGF overexpression and EAD yielded the highest frequency of renal dysfunction and the worst survival. Based on allograft weight and intrahepatic VEGF expression, an EAD risk assessment model was developed. The incidence of EAD differed significantly between grafts with risk scores ≥-1.72 and <-1.72. The model functioned well in the validation cohort.

CONCLUSIONS

Pretransplant intrahepatic protein profiling contributes to the estimation of early graft performance and recipient outcomes following LT. The predictive model could allow for an accurate prediction of EAD.

How Inaccurate Metrics Hide the True Potential for Organ Donation in the United States

BACKGROUND

There is a discrepancy between the reported increase in donor conversion rates and the number of organs available for transplant.

METHODS

Secondary analysis of data obtained from the Scientific Registry of Transplant Recipients from January 2003 through December 2015 was performed. The primary outcomes were the (1) number of brain-dead donors from whom solid organs were recovered and (2) number of the organs transplanted. Descriptive statistics and growth plots were used to examine the trajectory of organ donation, recovery, and transplantation outcomes over the 11-year period.

RESULTS

From 2003 to 2006, the number of brain-dead donors increased from 6187 to 7375, remaining relatively stable at approximately 7200 thereafter. The average eligible deaths per organ procurement organization dropped from 182.7 (standard deviation [SD]: 131.3) in 2003 to 149.3 (SD: 111.4) in 2015. This suggests a total of 12 493 unrealized potential donors (2006-2015).

CONCLUSIONS

Since 2006, a steady decline in the number of donor-eligible deaths was reported. In 2003, the reported eligible deaths was 11 326. This number peaked in 2004 at 11 346, tumbling to 9781 eligible donors in 2015, despite a 9% increase in the US population. From 2006 to 2015, the data indicate an artificial depression and underestimation of the true potential of brain-dead donors in the United States of conservatively 12 493 donors or 39 728 missing organs. New metrics providing objective but verifiable counts of the donor pool are needed.

Outcomes of Donation After Circulatory Death Liver Grafts From Donors 50 Years or Older: A Multicenter Analysis

BACKGROUND

As the population in the United States continues to age, an increase in the number of potential donation after circulatory death (DCD) donors with advanced chronological age can be expected. The aim of this study was to analyze a multi-institutional experience in liver transplantation using DCD donors 50 years or older.

METHODS

All DCD liver transplant (LT) performed at Mayo Clinic Florida, Mayo Clinic Rochester, and Mayo Clinic Arizona from 2002 to 2016 were included. Recipients of DCD LT were divided into 2 groups: those with donors 50 years or older (N = 155) and those with donors younger than 50 years(N = 316).

RESULTS

Graft survival was similar between the DCD donors 50 years or older group and DCD donors younger than 50 group(P = 0.99). Graft survival at 1, 3, and 5 years was 87.0%, 75.6%, and 71.8% in the DCD donors 50 years or older group and 85.8%, 76.0%, and 70.4% in the DCD donors younger than 50 group.The rate of total biliary complications (32.3% vs 23.7%; P = 0.049) and of anastomotic strictures (16.1% vs 8.2%; P = 0.01) were higher in the DCD donors 50 years or older compared with the DCD donors younger than 50 group. No statistical significant difference in the rate of ischemic cholangiopathy (11.6% vs 7.6%; P = 0.15) was seen between the 2 groups. Due to homogeneous practice patterns at the involved institutions, additional Cox regression analysis using national data obtained from Scientific Registry of Transplant Recipients was used to evaluate predictors of graft failure in DCD donors 50 years or older. Significant predictors of graft failure included: a calculated Model for End-Stage Liver Disease score of 30 or higher (P < 0.001), mechanical ventilation at the time of transplant (P < 0.001), medical condition (in intensive care unit) (P = 0.002), and cold ischemia time (P < 0.001).

CONCLUSIONS

The present study demonstrates that acceptable graft and patient survival can be achieved with the usage of DCD LT with donors 50 years or older. Optimizing recipient selection criteria and minimizing cold ischemia time may further improve outcomes.

The use of old donors in liver transplantation

The process of ageing has an impact on the entire human body including the organ systems. In transplantation, professionals are daily faced with risk assessment of suitable donor offers , whether to accept a liver graft for a specific recipient. In this context, livers from elderly donors are more frequently accepted for transplantation, to increase the donor pool and compensate the high waiting list mortality. In the current practice it is not unusual to accept 60-year old donor livers for transplantation, as the donor demographics have significantly changed over the years. However, controversy exists regarding the use of livers from donors above 70 or 80 years, particular in combination with other risk factors, e.g. liver steatosis, warm ischaemia or long cold storage. This review focuses first on the impact of ageing on liver morphology and function. Second, we will highlight outcome after transplantation from elderly donors. Finally, we describe further risk factors and donor-recipient selection under the scope of old donor organs and include our institutional experience and policy.

The Current State of Liver Transplantation in the United States: Perspective From American Society of Transplant Surgeons (ASTS) Scientific Studies Committee and Endorsed by ASTS Council

This article is a review of the salient points and a future prospective based on the 2014 Organ Procurement and Transplantation Network (OPTN)/Scientific Registry of Transplant Recipients (SRTR) liver donation and transplantation data report recently published by the American Journal of Transplantation. Emphasis of our commentary and interpretation is placed on data relating to waitlist dynamics, organ utilization rates, the impact of recent advances in the treatment of hepatitis C, and the increases in end-stage renal disease among liver transplant candidates. Finally, we share our vision on potential areas of innovation that are likely to significantly improve the field of liver transplantation in the near future.

Transplantation of Declined Liver Allografts Following Normothermic Ex-Situ Evaluation

The demand for liver transplantation (LT) exceeds supply, with rising waiting list mortality. Utilization of high-risk organs is low and a substantial number of procured livers are discarded. We report the first series of five transplants with rejected livers following viability assessment by normothermic machine perfusion of the liver (NMP-L). The evaluation protocol consisted of perfusate lactate, bile production, vascular flows, and liver appearance. All livers were exposed to a variable period of static cold storage prior to commencing NMP-L. Four organs were recovered from donors after circulatory death and rejected due to prolonged donor warm ischemic times; one liver from a brain-death donor was declined for high liver function tests (LFTs). The median (range) total graft preservation time was 798 (range 724-951) min. The transplant procedure was uneventful in every recipient, with immediate function in all grafts. The median in-hospital stay was 10 (range 6-14) days. At present, all recipients are well, with normalized LFTs at median follow-up of 7 (range 6-19) months. Viability assessment of high-risk grafts using NMP-L provides specific information on liver function and can permit their transplantation while minimizing the recipient risk of primary graft nonfunction. This novel approach may increase organ availability for LT.

A novel compartmentalised stent graft to isolate the perfusion of the abdominal organs

Donation after cardiac death has been adopted to address the critical shortage of donor organs for transplant. Recovery of these organs is hindered by low blood flow that leads to permanent organ injury. We propose a novel approach to isolate the perfusion of the abdominal organs from the systemic malperfusion of the dying donor. We reasoned that this design could improve blood flow to organs without open surgery, while respecting the ethical principle that cardiac stress not be increased during organ recovery. Conditions within the stent were analysed using a computational fluid dynamics (CFD) method and validated on two prototypes in vitro. The hydrodynamic pressure drop across the stent was measured as 0.14-0.22 mmHg, which is a negligible influence. Device placement studies were also conducted on swine model fluoroscopically. All these results demonstrated the feasibility of rapidly isolating the perfusion to abdominal organs using a compartmentalised stent graft design.

Early allograft dysfunction after liver transplantation: an intermediate outcome measure for targeted improvements

BACKGROUND

The term early allograft dysfunction (EAD) identifies liver transplant (LT) allografts with initial poor function and portends poor allograft and patient survival. Aims of this study are to use EAD as an intermediate outcome measure in a large single center cohort and identify donor, recipient and peri-operative risk factors.

MATERIAL AND METHODS

In 1950 consecutive primary LT, donor, recipient and peri-operative data were collected. EAD was defined by the presence of one or more of the following: total bilirubin ≥ 10 mg/dL (171 μmol/L) or, INR ≥ 1.6 on day 7, and ALT/AST > 2,000 IU/L within the first 7 days.

RESULTS

The incidence of EAD was 26.5%. 1-, 3-, and 5-year allograft and patient survival for patients who developed EAD were significantly inferior to those who did not (P < 0.01 at all time points). Multivariate analysis demonstrated associations in the development of EAD with recipient pre-operative ventilator status, donation after cardiac death allografts, donor age, allograft size, degree of steatosis, operative time and intra-operative transfusion requirements (all P < 0.01). Patients with EAD had a significantly longer hospitalization at 20.9 ± 38.9 days (median: 9; range: 4-446) compared with 10.7 ± 13.5 days (median: 7; range: 3-231) in patients with no EAD (P < 0.01).

CONCLUSIONS

This is the largest single center experience demonstrating incidence of EAD and identifying factors associated with development of EAD. EAD is a useful intermediate outcome measure for allograft and patient survival. Balancing recipient pretransplant conditions, donor risk factors and intra-operative conditions are necessary for avoiding EAD.

Targeting the Innate Immune Response to Improve Cardiac Graft Recovery after Heart Transplantation: Implications for the Donation after Cardiac Death

Heart transplantation (HTx) is the ultimate treatment for end-stage heart failure. The number of patients on waiting lists for heart transplants, however, is much higher than the number of available organs. The shortage of donor hearts is a serious concern since the population affected by heart failure is constantly increasing. Furthermore, the long-term success of HTx poses some challenges despite the improvement in the management of the short-term complications and in the methods to limit graft rejection. Myocardial injury occurs during transplantation. Injury initiated in the donor as result of brain or cardiac death is exacerbated by organ procurement and storage, and is ultimately amplified by reperfusion injury at the time of transplantation. The innate immune system is a mechanism of first-line defense against pathogens and cell injury. Innate immunity is activated during myocardial injury and produces deleterious effects on the heart structure and function. Here, we briefly discuss the role of the innate immunity in the initiation of myocardial injury, with particular focus on the Toll-like receptors and inflammasome, and how to potentially expand the donor population by targeting the innate immune response.

The Use of Donation After Cardiac Death Allografts Does Not Increase Recurrence of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) recurrence in patients undergoing liver transplantation (LT) with donation after brain death (DBD) and donation after cardiac death (DCD) allografts has not previously been investigated. Rates and patterns of HCC recurrences were investigated in patients undergoing DBD (N = 1633) and DCD (N = 243) LT between 2003 and 2012. LT for HCC was identified in 397 patients (340 DBD and 57 DCD). No difference in tumor number (p = 0.26), tumor volume (p = 0.34) and serum alphafetoprotein (AFP) (p = 0.47) was seen between the groups. HCC recurrence was identified in 41 (12.1%) patients in the DBD group and 7 (12.3%) patients in the DCD group. There was no difference in recurrence-free survival (p = 0.29) or cumulative incidence of HCC recurrence (p = 0.91) between the groups. Liver allograft was the first site of recurrence in 22 (65%) patients in the DBD group and two (37%) patients in the DCD group (p = 0.39). LT for HCC with DBD and DCD allografts demonstrate no difference in the rate of HCC recurrence. Previously published differences in survival demonstrated between recipients with HCC receiving DBD and DCD allografts despite statistical adjustment can likely be explained by practice patterns not captured by variables contained in the SRTR database.

Competition in liver transplantation: helpful or harmful?

Improved outcomes of liver transplantation have led to increases in the numbers of US transplant centers and candidates on the list. The resultant and ever-expanding organ shortage has created competition among centers, especially in regions with multiple liver transplant programs. Multiple reports now document that competition among the country's transplant centers has led to the listing of increasingly high-risk patients and the utilization of more marginal liver allografts. The transplant and medical communities at large should carefully re-evaluate these practices and promote innovative approaches to restoring trust in the allocation of donor organs and confirming that there is nationwide conformity in the guidelines used for evaluating and listing potential candidates for this scarce resource.

Inferior long-term outcomes of liver-kidney transplantation using donation after cardiac death donors: single-center and organ procurement and transplantation network analyses

Limited data are available for outcomes of simultaneous liver-kidney (SLK) transplantation using donation after cardiac death (DCD) donors. The outcomes of 12 DCD-SLK transplants and 54 SLK transplants using donation after brain death (DBD) donors were retrospectively compared. The baseline demographics were similar for the DCD-SLK and DBD-SLK groups except for the higher liver donor risk index for the DCD-SLK group (1.8 ± 0.4 versus 1.3 ± 0.4, P = 0.001). The rates of surgical complications and graft rejections within 1 year were comparable for the DCD-SLK and DBD-SLK groups. Delayed renal graft function was twice as common in the DCD-SLK group. At 1 year, the serum creatinine levels and the iothalamate glomerular filtration rates were similar for the groups. The patient, liver graft, and kidney graft survival rates at 1 year were comparable for the groups (83.3%, 75.0%, and 82.5% for the DCD-SLK group and 92.4%, 92.4%, and 92.6% for the DBD-SLK group, P = 0.3 for all). The DCD-SLK group had worse patient, liver graft, and kidney graft survival at 3 years (62.5%, 62.5%, and 58.9% versus 90.5%, 90.5%, and 90.6%, P = 0.03 for all) and at 5 years (62.5%, 62.5%, and 58.9% versus 87.4%, 87.4%, and 87.7%, P < 0.05 for all). An analysis of the Organ Procurement and Transplantation Network database showed inferior 1- and 5-year patient and graft survival rates for DCD-SLK patients versus DBD-SLK patients. In conclusion, despite comparable rates of surgical and medical complications and comparable kidney function at 1 year, DCD-SLK transplantation was associated with inferior long-term survival in comparison with DBD-SLK transplantation.

Standardized deceased donor kidney donation rates in the UK reveal marked regional variation and highlight the potential for increasing kidney donation: a prospective cohort study†

Background

The UK has implemented a national strategy for organ donation that includes a centrally coordinated network of specialist nurses in organ donation embedded in all intensive care units and a national organ retrieval service for deceased organ donors. We aimed to determine whether despite the national approach to donation there is significant regional variation in deceased donor kidney donation rates.

Methods

The UK prospective audit of deaths in critical care was analysed for a cohort of patients who died in critical care between April 2010 and December 2011. Multivariate logistic regression was used to identify the factors associated with kidney donation. The logistic regression model was then used to produce risk-adjusted funnel plots describing the regional variation in donation rates.

Results

Of the 27 482 patients who died in a critical care setting, 1528 (5.5%) became kidney donors. Factors found to influence donation rates significantly were: type of critical care [e.g. neurointensive vs general intensive care: OR 1.53, 95% confidence interval (CI) 1.34–1.75, P<0.0001], patient ethnicity (e.g. ‘Asian’ vs ‘white’: OR 0.17, 95% CI 0.11–0.26, P<0.0001), age (e.g. age >69 vs age 18–39 yr: OR 0.2, 0.15–0.25, P<0.0001), and cause of death [e.g. ‘other’ (excluding ‘stroke’ and ‘trauma’) vs ‘trauma’: OR 0.04, 95% CI 0.03–0.05, P<0.0001]. Despite correction for these variables, kidney donation rates for the 20 UK kidney donor regions showed marked variation. The overall standardized donation rate ranged from 3.2 to 7.5%. Four regions had donation rates of >2 standard deviations (sd) from the mean (two below and two above). Regional variation was most marked for donation after circulatory death (DCD) kidney donors with 9 of the 20 regions demonstrating donation rates of >2 sd from the mean (5 below and 4 above).

Conclusions

The marked regional variation in kidney donation rates observed in this cohort after adjustment for factors strongly associated with donation rates suggests that there is considerable scope for further increasing kidney donation rates in the UK, particularly DCD.

Update on islet transplantation

Clinical islet transplantation has progressed considerably over the past 12 years, and >750 patients with type 1 diabetes have received islet transplants internationally over this time. Many countries are beginning to accept the transition from research to accepted and funded clinical care, especially for patients with brittle control that cannot be stabilized by more conventional means. Major challenges remain, including the need for more than one donor, and the requirement for potent, chronic immunosuppression. Combining immunological tolerance both to allo- and autoantigens, and a limitless expandable source of stem cell- or xenograft-derived insulin-secreting cells represent remaining hurdles in moving this effective treatment to a potential cure for all those with type 1 or 2 diabetes.

Pediatric organ donation and transplantation

BACKGROUND AND OBJECTIVES

There is increasing unmet need for solid organ donation. Alternative donor sources, such as donation after circulatory determination of death (DCDD), are needed. The objective of this study was to examine the impact of DCDD on trends in pediatric organ donation and transplantation.

METHODS

Data were obtained from the Organ Procurement and Transplantation Network for US organ recipients and donors from 2001 to 2010 stratified according to age, organ, and deceased donor type (DCDD or donation after neurologic determination of death). Additional data included transplant wait-list removals due to death.

RESULTS

From 2001 to 2010, pediatric organ transplant recipients increased from 1170 to 1475. Organs from DCDD donors were transplanted into children infrequently but increased from 1 to 31. Pediatric donation after neurologic determination of death decreased by 13% whereas DCDD increased by 174% (50 to 137). Recipients of pediatric grafts decreased from 3042 to 2751. Adults receiving grafts from pediatric donors decreased from 2243 to 1780; children receiving pediatric grafts increased from 799 to 971. Transplant recipients receiving pediatric DCDD grafts were few but increased annually from 50 to 128 adults and 0 to 9 children. Pediatric candidates dying waiting for an organ decreased from 262 to 110.

CONCLUSIONS

From 2001 to 2010, children received more solid organ transplants and fewer children died waiting. Organ recovery from pediatric and adult DCDD donors increased. The number of pediatric recipients of DCDD grafts remains small. Adults primarily receive the direct benefit from pediatric DCDD but other changes in organ allocation have directly benefited children.

An international comparison of the effect of policy shifts to organ donation following cardiocirculatory death (DCD) on donation rates after brain death (DBD) and transplantation rates

During the past decade an increasing number of countries have adopted policies that emphasize donation after cardiocirculatory death (DCD) in an attempt to address the widening gap between the demand for transplantable organs and the availability of organs from donation after brain death (DBD) donors. In order to examine how these policy shifts have affected overall deceased organ donor (DD) and DBD rates, we analyzed deceased donation rates from 82 countries from 2000–2010. On average, overall DD, DBD and DCD rates have increased over time, with the proportion of DCD increasing 0.3% per year (p = 0.01). Countries with higher DCD rates have, on average, lower DBD rates. For every one-per million population (pmp) increase in the DCD rate, the average DBD rate decreased by 1.02 pmp (95% CI: 0.73, 1.32; p<0.0001). We also found that the number of organs transplanted per donor was significantly lower in DCD when compared to DBD donors with 1.51 less transplants per DCD compared to DBD (95% CI: 1.23, 1.79; p<0.001). Whilst the results do not infer a causal relationship between increased DCD and decreased DBD rates, the significant correlation between higher DCD and lower DBD rates coupled with the reduced number of organs transplanted per DCD donor suggests that a national policy focus on DCD may lead to an overall reduction in the number of transplants performed.

The faltering solid organ donor pool in the United States (2001-2010)

BACKGROUND

Organ shortage is the greatest challenge facing the field of organ transplantation today. Use of more organs of marginal quality has been advocated to address the shortage.

METHOD

We examined the pattern of donation and organ use in the United States as shown in the Organ Procurement and Transplantation Network/United Network for Organ Sharing database of individuals who were consented for and progressed to organ donation between January 2001 and December 2010.

RESULTS

There were 66,421 living donors and 73,359 deceased donors, including 67,583 (92.1%) identified as donation after brain death and 5,776 (7.9%) as donation after circulatory death (DCD). Comparing two periods, era 1 (01/2001-12/2005) and era 2 (01/2006-12/2010), the number of deceased donors increased by 20.3% from 33,300 to 40,059 while there was a trend for decreasing living donation. The DCD subgroup increased from 4.9 to 11.7% comparing the two eras. A significant increase in cardiovascular/cerebrovascular disease as a cause of death was also noted, from 38.1% in era 1 to 56.1% in era 2 (p<0.001), as was a corresponding decrease in the number of deaths due to head trauma (48.8 vs. 34.9%). The overall discard rate also increased from 13,411 (11.5%) in era 1 to 19,516 (13.7%) in era 2. This increase in discards was especially prominent in the DCD group [440 (20.9%) in era 1 vs. 2,089 (24.9%) in era 2].

CONCLUSIONS

We detect a significant change in pattern of organ donation and use in the last decade in the United States. The transplant community should consider every precaution to prevent the decay of organ quality and to improve the use of marginal organs.

Deceased donor risk factors influencing liver transplant outcome

As the pressure for providing liver transplantation to more and more candidates increases, transplant programs have begun to consider deceased donor characteristics that were previously considered unacceptable. With this trend, attention has focused on better defining those donor factors that can impact the outcome of liver transplantation. This review examines deceased donor factors that have been associated with patient or graft survival as well as delayed graft function and other liver transplant results.

Declining liver utilization for transplantation in the United States and the impact of donation after cardiac death

Worsening donor liver quality resulting in decreased organ utilization may be contributing to the recent decline in liver transplants nationally. We sought to examine trends in donor liver utilization and the relationship between donor characteristics and nonuse. We used the United Network for Organ Sharing database to review all deceased adult organ donors in the United States from whom at least 1 solid organ was transplanted into a recipient. Trends in donor characteristics were examined. Multivariate logistic regression was used to evaluate the association between donor characteristics and liver nonuse between 2004 and 2010. Population attributable risk proportions were determined for donor factors associated with nonuse. We analyzed 107,259 organ donors. The number of unused livers decreased steadily from 1958 (66% of donors) in 1988 to 841 (15%) in 2004 but then gradually increased to 1345 (21%) in 2010. The donor age, the body mass index (BMI), and the prevalence of diabetes and donation after cardiac death (DCD) all increased over time, and all 4 factors were independently associated with liver nonuse. DCD had the highest adjusted odds ratio (OR) for nonuse, and the odds increased nearly 4-fold between 2004 [OR = 5.53, 95% confidence interval (CI) = 4.57-6.70] and 2010 (OR = 21.31, 95% CI = 18.30-24.81). The proportion of nonuse attributable to DCD increased from 9% in 2004 to 28% in 2010. In conclusion, the proportion of donor livers not used has increased since 2004. Older donor age, greater BMI, diabetes, and DCD are all independently associated with nonuse and are on the rise nationally. Current trends may lead to significant declines in liver transplant availability.

Establishment of a rat liver transplantation model with prolonged biliary warm ischemia time

AIM: To investigate the impact of different time points of secondary warm ischemia on bile duct in a rat autologous liver transplantation model with external bile drainage.

METHODS: One hundred and thirty-six male inbred SD rats were randomly assigned to one of four groups (I-IV) according to the secondary warm ischemia time of 0, 10, 20 and 40 min. A rat model of autologous liver transplantation with continuous external biliary drainage under ether anesthesia was established. Ten rats in each group were used to evaluate the one-week survival rate. At 6 h, 24 h, 3 d and 7 d after reperfusion of the hepatic artery, 6 rats were killed in each group to collect the blood sample via the infrahepatic vena cava and the median lobe of liver for assay. Warm ischemia time of liver, cold perfusion time, anhepatic phase, operative duration for biliary external drainage and survival rates in the four groups were analyzed for the establishment of models.

RESULTS: No significant difference was shown in warm ischemia time, anhepatic phase and operative duration for biliary external drainage among the four groups. Five of the 40 rats in this study evaluated for the one-week survival rate died, including three deaths of severe pulmonary infection in group IV. A significant decrease of one-week survival rate in group IV was noted compared with the other three groups. With the prolongation of the biliary warm ischemia time, the indexes of the liver function assessment were significantly elevated, and biliary epithelial cell apoptosis index also increased. Pathological examinations showed significantly aggravated inflammation in the portal area and bile duct epithelial cell injury with the prolonged secondary warm ischemia time. Microthrombi were found in the micrangium around the biliary tract in some sections from groups III and IV.

CONCLUSION: The relationship between secondary warm ischemia time and the bile duct injury degree is time-dependent, and 20 min of secondary warm ischemia time is feasible for the study of bile duct injury.

Effects of warm ischemia time on biliary injury in rat liver transplantation

AIM: To investigate the effect of different secondary warm ischemia time (SWIT) on bile duct injury in liver-transplanted rats.

METHODS: Forty-eight male inbred Sprague-Dawley rats were randomly assigned into four groups: a sham-operation group and three groups with secondary biliary warm ischemia time of 0 min, 10 min and 20 min. A rat model of autologous liver transplantation under ether anesthesia was established, and six rats were killed in each group and blood samples and the median lobe of the liver were collected for assay at 6 h and 24 h after hepatic arterial reperfusion.

RESULTS: With prolongation of biliary warm ischemia time, the level of vascular endothelial growth factor-A was significantly decreased, and the value at 24 h was higher than that at 6 h after hepatic arterial reperfusion, but with no significant difference. The extended biliary SWIT led to a significant increase in bile duct epithelial cell apoptosis, and a decrease in the number of blood vessels, the bile duct surrounding the blood vessels and bile duct epithelial cell proliferation in the early postoperative portal area. Pathologic examinations showed that inflammation of the rat portal area was aggravated, and biliary epithelial cell injury was significantly worsened.

CONCLUSION: A prolonged biliary warm ischemia time results in aggravated injury of the bile duct and the surrounding vascular plexus in rat autologous orthotopic liver transplantation.

Excellent clinical outcomes from a national donation-after-determination-of-cardiac-death lung transplant collaborative

Donation-after-Determination-of-Cardiac-Death (DDCD) donor lungs can potentially increase the pool of lungs available for Lung Transplantation (LTx). This paper presents the 5-year results for Maastricht category III DDCD LTx undertaken by the multicenter Australian National DDCD LTx Collaborative. The Collaborative was developed to facilitate interaction with the Australian Organ Donation Authority, standardization of definitions, guidelines, education and audit processes. Between 2006 and 2011 there were 174 actual DDCD category III donors (with an additional 37 potentially suitable donors who did not arrest in the mandated 90 min postwithdrawal window), of whom 71 donated lungs for 70 bilateral LTx and two single LTx. In 2010 this equated to an "extra" 28% of donors utilized for LTx. Withdrawal to pulmonary arterial flush was a mean of 35.2 ± 4.0 min (range 18-89). At 24 h, the incidence of grade 3 primary graft dysfunction was 8.5%[median PaO(2)/FiO(2) ratio 315 (range 50-507)]. Overall the incidence of grade 3 chronic rejections was 5%. One- and 5-year actuarial survival was 97% and 90%, versus 90% and 61%, respectively, for 503 contemporaneous brain-dead donor lung transplants. Category III DDCD LTx therefore provides a significant, practical, additional quality source of transplantable lungs.

Asystole to cross-clamp period predicts development of biliary complications in liver transplantation using donation after cardiac death donors

This study sought to determine the procurement factors that lead to development of intrahepatic bile duct strictures (ITBS) and overall biliary complications in recipients of donation after cardiac death (DCD) liver grafts. Detailed information for different time points during procurement (withdrawal of support; SBP < 50 mmHg; oxygen saturation <30%; mandatory wait period; asystole; incision; aortic cross clamp) and their association with the development of ITBS and overall biliary complications were examined using logistic regression. Two hundred and fifteen liver transplants using DCD donors were performed between 1998 and 2010 at Mayo Clinic Florida. Of all the time periods during procurement, only asystole-cross clamp period was significantly different between patients with ITBS versus no ITBS (P = 0.048) and between the patients who had overall biliary complications versus no biliary complications (P = 0.047). On multivariate analysis, only asystole-cross clamp period was significant predictor for development of ITBS (P = 0.015) and development of overall biliary complications (P = 0.029). Hemodynamic changes in the agonal period did not emerge as risk factors. The results of the study raise the possibility of utilizing asystole-cross-clamp period in place of or in conjunction with donor warm ischemia time in determining viability or quality of liver grafts.

Strategies toward single-donor islets of Langerhans transplantation

PURPOSE OF REVIEW

The current review addresses a critical need in clinical islet transplantation, namely the routine transition from the requirement of two to four donors down to one donor per recipient. The ability to achieve single-donor islet transplantation will provide many more islet grafts for treatment of an ever-expanding patient base with type 1 diabetes (T1DM) with poor glycemic control. Avoiding exposure of recipients to multiple different donor human leukocyte associated (HLA) antigens is critical if risk of donor sensitization is to be avoided. This point is important as further islet or pancreas transplants in the remote future or the potential future need for a solid organ kidney transplant may become prohibitive if the recipient is sensitized.

RECENT FINDINGS

This review addresses systematically all areas that contribute to the success or failure of single-donor islet engraftment, beginning with donor-related factors, optimizing islet isolation and culture conditions, and describes a series of strategies in the treatment of the recipient to prevent inflammation, apoptosis, islet thrombosis, and improve metabolic functional outcome, all of which will lead to improved single-donor engraftment success.

SUMMARY

If single-donor islet transplantation can be achieved routinely, therapy will become more widely available, more accepted by the transplant community (currently pancreas transplantation requires only a single donor), and this situation will have a major impact overall as an effective treatment option in T1DM.

Events in procurement as risk factors for ischemic cholangiopathy in liver transplantation using donation after cardiac death donors

The use of donation after cardiac death (DCD) liver grafts is controversial because of the overall increased rates of graft loss and morbidity, which are mostly related to the consequences of ischemic cholangiopathy (IC). In this study, we sought to determine the factors leading to graft loss and the development of IC and to compare patient and graft survival rates for recipients of DCD liver grafts and recipients of donation after brain death (DBD) liver grafts in a large series at a single transplant center. Two hundred liver transplants with DCD donors were performed between 1998 and 2010 at Mayo Clinic Florida. Logistic regression models were used in the univariate and multivariate analyses of predictors for the development of IC. Additional analyses using Cox regression models were performed to identify predictors of graft survival and to compare outcomes for DCD and DBD graft recipients. In our series, the patient survival rates for the DCD and DBD groups at 1, 3, and 5 years was 92.6%, 85%, and 80.9% and 89.8%, 83.0%, and 76.6%, respectively (P = not significant). The graft survival rates for the DCD and DBD groups at 1, 3, and 5 years were 80.9%, 72.7%, and 68.9% and 83.3%, 75.1%, and 68.6%, respectively (P = not significant). In the DCD group, 5 patients (2.5%) had primary nonfunction, 7 patients (3.5%) had hepatic artery thrombosis, and 3 patients (1.5%) experienced hepatic necrosis. IC was diagnosed in 24 patients (12%), and 11 of these patients (5.5%) required retransplantation. In the multivariate analysis, the asystole-to-cross clamp duration [odds ratio = 1.161, 95% confidence interval (CI) = 1.021-1.321] and African American recipient race (odds ratio = 5.374, 95% CI = 1.368-21.103) were identified as significant factors for predicting the development of IC (P < 0.05). This study has established a link between the development of IC and the asystole-to-cross clamp duration. Procurement techniques that prolong the nonperfusion period increase the risk for the development of IC in DCD liver grafts.

Remarkable changes in the choice of timing to discuss organ donation with the relatives of a patient: a study in 228 organ donations in 20 years

Introduction

We studied whether the choice of timing of discussing organ donation for the first time with the relatives of a patient with catastrophic brain injury in The Netherlands has changed over time and explored its possible consequences. Second, we investigated how thorough the process of brain death determination was over time by studying the number of medical specialists involved. And we studied the possible influence of the Donor Register on the consent rate.

Methods

We performed a retrospective chart review of all effectuated brain dead organ donors between 1987 and 2009 in one Dutch university hospital with a large neurosurgical serving area.

Results

A total of 271 medical charts were collected, of which 228 brain dead patients were included. In the first period, organ donation was discussed for the first time after brain death determination (87%). In 13% of the cases, the issue of organ donation was raised before the first EEG. After 1998, we observed a shift in this practice. Discussing organ donation for the first time after brain death determination occurred in only 18% of the cases. In 58% of the cases, the issue of organ donation was discussed before the first EEG but after confirming the absence of all brain stem reflexes, and in 24% of the cases, the issue of organ donation was discussed after the prognosis was deemed catastrophic but before a neurologist or neurosurgeon assessed and determined the absence of all brain stem reflexes as required by the Dutch brain death determination protocol.

Conclusions

The phases in the process of brain death determination and the time at which organ donation is first discussed with relatives have changed over time. Possible causes of this change are the introduction of the Donor Register, the reintroduction of donation after circulatory death and other logistical factors. It is unclear whether the observed shift contributed to the high refusal rate in The Netherlands and the increase in family refusal in our hospital in the second studied period. Taking published literature on this subject into account, it is possible that this may have a counterproductive effect.

Is organ donation from brain dead donors reaching an inescapable and desirable nadir?

The brain dead patient is the ideal multiorgan donor. Conversely, brain death (BD) is an undesirable outcome of critical care medicine. Conditions that can lead to the state of BD are limited. An analysis showed that a (aneurysmal) subarachnoid hemorrhage, traumatic brain injury, or intracerebral hemorrhage in 83% precede the state of BD. Because of better prevention and treatment options, we should anticipate on an inescapable and desirable decline of BD. In this article, we offer arguments for this statement and discuss alternatives to maintain a necessary level of donor organs for transplantation.