Importance and Potential of European Cross-Border Deceased Donor Organ Allocation Through FOEDUS-EOEO Platform

The FOEDUS-EOEO platform was relaunched in 2015 to allocate deceased donor organs across European borders when there are no suitable recipients in the donor's country. We analyzed organ offers from 01.06.2015-31.12.2021 and present the number of offers and transplants, and utilization as percentage of transplanted organs. 1,483 organs were offered, 287 were transplanted (19.4% utilization). Yearly number of offers and transplants increased from 2017 to 2021, while utilization stabilized after 2018. Utilization was highest for organs offered by Slovakia (47.2%), followed for organs offered by Lithuania, France, Greece, and Czechia (19.3%-22.9%). The most frequently offered organ was the heart (n = 405; 27.3%), followed by the lungs (n = 369; 24.9%) and the liver (n = 345; 23.3%). Utilization differed significantly by organ type (highest for liver, 35.7%; followed by heart, 18.8%; and kidney, 18.3%) and by donor age (highest for 1 to 5 year-old donors (25.0%)). FOEDUS-EOEO allowed for many European patients receiving a long-awaited transplant, especially for very young pediatric patients waiting for a liver, a heart, or a kidney. The increasing number of participating countries has increased both the number of offered organs and, to a lesser extent, the number of transplanted organs.

The impact of perceived donor liver quality on post-transplant outcome

BACKGROUND

We analysed the impact of perceived liver donor quality on transplant recipient outcomes.

METHODS

this prospective cohort study included all deceased liver donors during 2008-2018 in the Swiss Transplant Cohort Study. Perceived low-quality liver donors were defined when refused for ≥5 top listed recipients or for all recipients in at least one centre before being transplanted. The effect of liver donor quality on relisting or recipient death at 1 week and 1 year after transplantation was analysed using Kaplan-Meier and Cox proportional hazard models. A 1:3 matching was also performed using a recipient score.

RESULTS

Of 973 liver donors, 187 (19.2%) had perceived poor-quality. Males, obesity, donation after circulatory death and alanine aminotransferase values were significantly associated with perceived poor-quality, with no significant effect of the perceived quality on re-listing or death within the first week and first year post-transplant [(aHR) = 1.45, 95% CI: (0.6, 3.5), P = 0.41 and aHR = 1.52 (95% CI 0.98-2.35), P = 0.06], adjusting by recipient age and gender, obesity, diabetes, prior liver transplantation and model for end-stage liver disease (MELD) score. At 1 year, prior liver transplantation and higher MELD score associated with higher risk of re-listing or death.

CONCLUSION

Comparable post-transplant outcomes with different perceived quality liver donors stresses the need to improve donor selection in liver transplantation.

The MELD upgrade exception: a successful strategy to optimize access to liver transplantation for patients with high waiting list mortality

BACKGROUND

MELD exceptions are designed to equipoise liver transplant waiting list survival. We aimed to analyze the impact of the MELD Upgrade rule and all other MELD exceptions on the liver transplant waiting list outcomes during 2012-2017 in Switzerland.

METHODS

We conducted a nationwide cohort study including all adult patients registered on the Swiss liver transplant waiting list between 2012 and 2017. Waiting list mortality and access to transplantation were analyzed, considering MELD exceptions as time-dependent covariates.

RESULTS

730 patients were included. Patients with MELD Upgrade exceptions had a higher risk of dying while on the waiting list (OR 2.13; CI 95% 1.30-3.47) and also an increased likelihood of receiving a liver transplantation, when compared to patients without MELD exceptions. Patients with any type of MELD exceptions were more likely to be transplanted when compared to patients without MELD exceptions. The proportion of patients with MELD exceptions increased from 2012 to 2017 (44% vs 88%). Allocation MELD at the time of transplantation showed an annual increase (23 ± 8 points vs 32 ± 5 points, p < 0.001).

CONCLUSION

Only patients with MELD Upgrade exceptions had the expected combination of higher waiting list mortality and quicker access to liver transplantation.

Organ donation after circulatory death as compared with organ donation after brain death in Switzerland - an observational study

AIMS OF THE STUDY

Organ donation after circulatory death (DCD) was reintroduced in Switzerland in 2011 and accounts for a third of deceased organ donors today. Controversy persists if DCD transplants are of similar quality to transplants following donation after brain death (DBD), mainly due to warm ischaemia time DCD organs are exposed to. We compared DCD with DBD in Switzerland.

METHODS

Data on deceased adults who were referred to and approved for organ donation from 1 September 2011 to 31 December 2019 were retrospectively analysed (217 DCD, 840 DBD donors). We compared DCD and DBD donor/organ characteristics, transplant rates of lungs, liver, kidneys, and pancreas, and early liver and kidney graft function in the recipient. The effect of DCD/DBD on transplant rates (organ transplanted or not) and 72-hour recipient graft function (moderate/good vs delayed graft function / organ loss) was analysed using multivariable logistic regression. Among utilised DCD donors, we analysed the effect of functional warm ischaemia time (FWIT) and donor age on 72-hour post-transplant liver and kidney graft function, also using multivariable logistic regression.

RESULTS

DCD donors were more often male (64.5% vs 56.8% p = 0.039), presented with heart disease (36.4% vs 25.5%, p <0.001), were resuscitated before hospital admission (41.9% vs 30.7%, p = 0.006), and died from anoxia (41.9% vs 23.9%). Kidney function before transplantation was comparable, lung, liver and pancreas function were poorer in DCD than DBD. Eighty-one and 91% of approved DCD and DBD donors were utilised (p <0.001). Median FWIT in DCD was 29 minutes (interquartile range 25-35). DCD transplant rates ranged from 4% (pancreas) to 73% (left kidney) and were all lower compared with DBD. Seventy-two-hour liver graft function was comparable between DCD and DBD (94.2% vs 96.6% moderate/good, p = 0.199). DCD kidney transplants showed increased risk of delayed graft function or early organ loss (odds ratios 8.32 and 5.05; 95% confidence intervals CI 5.28-13.28 and 3.22-7.95; both p <0.001, for left and right kidney transplants, respectively). No negative effect of prolonged FWIT or higher donor age was detected.

CONCLUSION

Despite less favourable donor/organ characteristics compared with donation after brain death, donation after circulatory death donors are increasingly referred and today provide an important source for scarce transplants in Switzerland. We identified a higher risk for delayed graft function or early organ loss for DCD kidney transplants, but not for DCD liver transplants. When carefully selected and allowed for other risk factors in organ allocation, prolonged functional warm ischaemia time or higher age in donation after circulatory death does not seem to be associated with impaired graft function early after transplantation.

Access of non-residents to transplantation of deceased donor organs: practices and strategies in the European setting

The access of non-resident patients to the deceased donor waiting list (DDWL) poses different challenges. The European Committee on Organ Transplantation of the Council of Europe (CD-P-TO) has studied this phenomenon in the European setting. A questionnaire was circulated among the Council of Europe member states to inquire about the criteria applied for non-residents to access their DDWL. Information was compiled from 28 countries. Less than 1% of recipients of deceased donor organs were non-residents. Two countries never allow non-residents to access the DDWL, four allow access without restrictions and 22 only under specific conditions. Of those, most give access to non-resident patients already in their jurisdictions who are in a situation of vulnerability (urgent life-threatening conditions). In addition, patients may be given access: (i) after assessment by a specific committee (four countries); (ii) within the framework of official cooperation agreements (15 countries); and (iii) after patients have officially lived in the country for a minimum length of time (eight countries). The ethical and legal implications of these policies are discussed. Countries should collect accurate information about residency status of waitlisted patients. Transparent criteria for the access of non-residents to DDWL should be clearly defined at national level.

Impact of cardiopulmonary resuscitation on organ donation in Switzerland

AIMS OF THE STUDY

The lack of suitable donor organs limits the number of solid organ transplants. Patients who underwent cardiopulmonary resuscitation (CPR) after cardiac arrest may represent a sizeable subgroup of deceased organ donors, as they often progress to brain death or have life-sustaining therapy withdrawn. We aimed to quantify deceased organ donation after CPR in Switzerland for the first time by analysing the characteristics of potential and utilised organ donors after CPR.

METHODS

Data on deceased adult and paediatric patients who were reported to and approved by Swisstransplant for organ donation were analysed, including both donation after brain death (DBD) and donation after controlled cardiocirculatory death (cDCD) from 2016 to 2018. We analysed baseline characteristics of potential donors who underwent CPR in the context of their hospitalisation, as compared with donors without prior CPR. Considering the varying characteristics between these two donor groups, we assessed the effect of CPR on different allocation outcomes (donor and organ utilisation, organ yield per utilised donor) using multivariable regression. Additionally, we present selected CPR circumstances and compared different subgroups of CPR donors according to duration of CPR and duration of no-flow time.

RESULTS

Of the 461 deceased potential organ donors included in the analysis, 173 (37.5%) underwent CPR. CPR donors were, on average, younger (median age 53 vs 62, p &lt;0.001), had different causes of death (p &lt;0.001), and were more often of the cDCD type (30.1% vs 18.4%, p = 0.004) as compared with non-CPR donors. Of the 173 CPR donors, 152 (87.9%) could be utilised (minimum one organ transplanted), and in the multivariable analysis, utilisation rate was higher in the CPR donor group than in the non-CPR donor group (odds ratio 3.3, 95% confidence interval 1.1&ndash;11.5; p = 0.046). Organ specific utilisation of heart, liver, and kidney, and total organ yield per donor, did not differ significantly between CPR and non-CPR donors.

CONCLUSION

Our study reveals that a substantial proprotion of deceased organ donors in Switzerland underwent CPR in context of their hospitalisation. CPR donors are different from non-CPR donors with respect to age, cause of death and donation type. However, when carefully selected according to their haemodynamic condition, CPR donors are comparable to non-CPR donors in terms of donor and organ utilisation, as well as the average organ yield. Thus, all patients who are resuscitated from cardiac arrest but who subsequently progress to death should be evaluated for organ donation. How CPR donors compare with non-CPR donors regarding transplant outcomes should be studied further.

SARS-CoV-2 / COVID-19 in patients on the Swiss national transplant waiting list

AIMS OF THE STUDY

The impact of coronavirus disease 2019 (COVID-19) on patients listed for solid organ transplantation has not been systematically investigated to date. Thus, we assessed occurrence and effects of infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on patients on the Swiss national waiting list for solid organ transplantation.

METHODS

Patient data were retrospectively extracted from the Swiss Organ Allocation System (SOAS). From 16 March to 31 May 2020, we included all patients listed for solid organ transplantation on the Swiss national waiting list who were tested positive for SARS-CoV-2. Severity of COVID-19 was categorised as follows: stage I, mild symptoms; stage II, moderate to severe symptoms; stage III, critical symptoms; stage IV, death. We compared the incidence rate (laboratory-confirmed cases of SARS-CoV-2), the hospital admission rate (number of admissions of SARS-CoV-2-positive individuals), and the case fatality rate (number of deaths of SARS-CoV-2-positive individuals) in our study population with the general Swiss population during the study period, calculating age-adjusted standardised incidence ratios and standardised mortality ratios, with 95% confidence intervals (CIs).

RESULTS

A total of 1439 patients were registered on the Swiss national solid organ transplantation waiting list on 31 May 31 2020. Twenty-four (1.7%) waiting list patients were reported to test positive for SARS-CoV-2 in the study period. The median age was 56 years (interquartile range 45.3&ndash;65.8), and 14 (58%) were male. Of all patients tested positive for SARS-CoV-2, two patients were asymptomatic, 14 (58%) presented in COVID-19 stage I, 3 (13%) in stage II, and 5 (21%) in stage III. Eight patients (33%) were admitted to hospital, four (17%) required intensive care, and three (13%) mechanical ventilation. Twenty-two patients (92%) of all those infected recovered, but two male patients aged &gt;65 years with multiple comorbidities died in hospital from respiratory failure. Comparing our study population with the general Swiss population, the age-adjusted standardised incidence ratio was 4.1 (95% CI 2.7&ndash;6.0).

CONCLUSION

The overall rate of SARS-CoV-2 infections in candidates awaiting solid organ transplantation was four times higher than in the Swiss general population; however, the frequency of testing likely played a role. Given the small sample size of affected patients, conclusions have to be drawn cautiously and results need verification in larger cohorts.

Management of allergy transfer upon solid organ transplantation

Allergy transfer upon solid organ transplantation has been reported in the literature, although only few data are available as to the frequency, significance, and management of these cases. Based on a review of 577 consecutive deceased donors from the Swisstransplant Donor-Registry, 3 cases (0.5%) of fatal anaphylaxis were identified, 2 because of peanut and 1 of wasp allergy. The sera of all 3 donors and their 10 paired recipients, prospectively collected before and after transplantation for the Swiss Transplant Cohort Study, were retrospectively processed using a commercial protein microarray fluorescent test. As early as 5 days posttransplantation, newly acquired peanut-specific IgE were transiently detected from 1 donor to 3 recipients, of whom 1 liver and lung recipients developed grade III anaphylaxis. Yet, to define how allergy testing should be performed in transplant recipients and to better understand the impact of immunosuppressive therapy on IgE sensitization, we prospectively studied 5 atopic living-donor kidney recipients. All pollen-specific IgE and >90% of skin prick tests remained positive 7 days and 3 months after transplantation, indicating that early diagnosis of donor-derived IgE sensitization is possible. Importantly, we propose recommendations with respect to safety for recipients undergoing solid-organ transplantation from donors with a history of fatal anaphylaxis.

Heart allocation and transplantation in Switzerland since the introduction of the Swiss Organ Allocation System (SOAS)

OBJECTIVE

To provide an overview of heart allocation and transplantation in Switzerland since the introduction of the Swiss Organ Allocation System (SOAS).

METHODS

This study is a retrospective analysis of SOAS data related to heart transplantation between 1 July 2007 and 30 June 30 2013.

RESULTS

During the study period, 300 patients were newly waitlisted for a heart transplant in Switzerland, 199 were transplanted and 52 deceased while on the waiting list. Of the 723 hearts offered by Swisstransplant to the three university hospitals with a heart transplantation programme (Bern, Lausanne and Zurich), 199 (27.5%) were transplanted. Of these, 183 (92.0%) were procured in Switzerland and 16 (8.0%) were offered by a foreign organ procurement organisation. Fifty-two hearts were transplanted to patients who were listed in urgent status, equalling an urgent transplant rate of 26.1%. Whereas the overall waiting list mortality was 19.0%, it was as high as 31.8% in patients older than 60 years.

CONCLUSIONS

Our study showed a growing Swiss heart transplant waiting list, as significantly more patients were newly waitlisted than transplanted. Compared with the international data, the acceptance rate of heart offers and the rate of urgent transplantations were relatively low, while the waiting list mortality was higher. The fact that the mortality was highest in candidates aged 60 and above suggests that the new generation of ventricular assist devices as destination therapy should be considered as an alternative to transplantation in selected patients.

Organ transplantation in Switzerland: impact of the new transplant law on cold ischaemia time and organ transports

BACKGROUND

On 1 July 2007 a new transplant law came into force in Switzerland. The principal item of this new law is the change from centre-oriented allocation to patient-oriented national allocation of organs. The aim of the present study is to assess the impact on cold ischaemia time (CIT) and transport requirements.

METHODS

From 1 July 2006 to 30 June 2008 168 brain-dead donors were registered by Swisstransplant in Switzerland. Donors have been analysed in a retrospective cohort study design. Donor characteristics, transportation requirements and CIT were assessed from the Necroreport.

RESULTS

74 donors (44%) were allocated in the period before the introduction of the new law (period A) and 94 donors (56%) after the new law. Donor characteristics were similar. In period A, 114 organs (37.9%) were allocated within the procurement centre, compared to 54 organs (15.5%) in period B. Transport time for liver and kidney was remarkably longer in period B. Overall, CITs remained largely stable except for a significant increase of nearly 115 minutes in the liver graft median CIT (p <0.01).

CONCLUSIONS

The new Swiss transplant law clearly entails an increase in the frequency of organ transports. Overall CIT is not affected. However, liver transplantation is afflicted by an increase in transports and CIT. This may affect mid-term outcome and should therefore be followed closely.

Strategies for single particle manipulation using acoustic and flow fields

Acoustic radiation forces have often been used for the manipulation of large amounts of micrometer sized suspended particles. The nature of acoustic standing wave fields is such that they are present throughout the whole fluidic volume; this means they are well suited to such operations, with all suspended particles reacting at the same time upon exposure. Here, this simultaneous positioning capability is exploited to pre-align particles along the centerline of channels, so that they can successively be removed by means of an external tool for further analysis. This permits a certain degree of automation in single particle manipulation processes to be achieved as initial identification of particles' location is no longer necessary, rather predetermined. Two research fields in which applications are found have been identified. First, the manipulation of copolymer beads and cells using a microgripper is presented. Then, sample preparation for crystallographic analysis by positioning crystals into a loop using acoustic manipulation and a laminar flow will be presented.

Temperature dependence of normal sensory nerve action potentials

Sensory conduction velocities of normal subjects are increasing linearly with rising temperature. The duration of the compound sensory action potentials recorded from the median nerve at the wrist and elbow shows a negative temperature coefficient. The peak-to-peak amplitude of these potentials increases from 22 degrees to approximately 26 degrees C and then decreases progressively again up to 36 degrees C. It is believed that this behavior is due to a combination of decreasing temporal dispersion, height and duration of the individual spike potentials.