Novel portable hypothermic machine perfusion preservation device enhances cardiac viability of donated human hearts.

Introduction: Heart transplant remains the gold standard treatment for patients with advanced heart failure. However, the list of patients waiting for a heart transplant continues to increase. We have developed a portable hypothermic oxygenated machine perfusion device, the VP.S ENCORE®, to extend the allowable preservation time. The purpose of this study was to test the efficacy of the VP.S. ENCORE® using deceased donors derived hearts. Methods: Hearts from brain-dead donors not utilized for transplant (n = 11) were offered for research from the Texas Organ Sharing Alliance (TOSA), South and Central Texas' Organ Procurement Organization (OPO) and were preserved in the VP.S ENCORE® for 4 (n = 2), 6 (n = 3), and 8 (n = 3) hours or were kept in static cold storage (SCS) (n = 3). After preservation, the hearts were placed in an isolated heart Langendorff model for reperfusion and evaluated for cardiac function. Results: The mean donor age was 37.82 ± 12.67 with the youngest donor being 19 and the oldest donor being 58 years old. SCS hearts mean weight gain (%) was -1.4 ± 2.77, while perfused at 4 h was 5.6 ± 6.04, perfused at 6 h 2.1 ± 6.04, and 8 h was 7.2 ± 10.76. Venous and arterial lactate concentrations were less than 2.0 mmol/L across all perfused hearts. Left ventricular contractility (+dPdT, mmHg/s) for 4 h (1,214 ± 1,064), 6 (1,565 ± 141.3), and 8 h (1,331 ± 403.6) were within the range of healthy human heart function. Thus, not significant as compared to the SCS group (1,597 ± 342.2). However, the left ventricular relaxation (mmHg/s) was significant in 6-hour perfused heart (p < 0.05) as compared to SCS. Gene expression analysis of inflammation markers (IL-6, IL-1ß) showed no significant differences between SCS and perfused hearts, but a 6-hour perfusion led to a downregulated expression of these markers. Discussion: The results demonstrate that the VP.S ENCORE® device enhances cardiac viability and exhibits comparable cardiac function to a healthy heart. The implications of these findings suggest that the VP.S ENCORE® could introduce a new paradigm in the field of organ preservation, especially for marginal hearts.

Liver biopsy in assessment of extended criteria donors.

The safety and liver utilization with prerecovery liver biopsy (PLB) in extended criteria liver donors are unclear. We conducted a retrospective cohort study in 1323 brain death donors (PLB = 496) from 3 organ procurement organizations (OPOs). Outcomes were complications, preempted liver recovery (PLR), and liver transplantation (LT). Additional analyses included liver-only and propensity score-matched multiorgan donor subgroups. PLB donors were older (57 versus 53 years; P < 0.001). Hepatitis C antibody positivity (14.3% versus 9.6%, P = 0.01) and liver-only donors (42.6% versus 17.5%; P < 0.001) were more prevalent. The PLB cohort had fewer complications (31.9% versus 42.3%; P < 0.001). In the PLB cohort, PLR was significantly higher (odds ratio [OR], 3.45; 95% confidence interval [CI], 2.42-4.92) and LT lower (OR, 0.69; 95% CI, 0.52-0.91). In liver-only and propensity score-matched multiorgan donor subgroups, PLR was significantly higher (OR, 1.76; 95% CI, 1.06-2.94 and OR, 2.29; 95% CI, 1.37-3.82, respectively) without a decrease in LT (OR, 0.71; 95% CI, 0.43-1.18 and OR, 0.91; 95% CI, 0.63-1.33, respectively) in PLB subgroups. In conclusion, in extended criteria liver donors, PLB is safe and decreases futile liver recovery without decreasing LT. Increased use of PLB, especially in liver-only donors, is likely to save costs to OPOs and transplant centers and improve efficiencies in organ allocation. Liver Transplantation 24 182-191 2018 AASLD.

Organ Procurement Organization Survey of Practices and Beliefs Regarding Prerecovery Percutaneous Liver Biopsy in Donation After Neurologic Determination of Death.

BACKGROUND: Prerecovery liver biopsy (PLB) allows histological evaluation of the organ before procurement. The opinions and what factors might influence PLB use within Organ Procurement Organizations (OPOs) are unknown. METHODS: A survey instrument was distributed by the Association of OPOs to the clinical directors of all 58 OPOs. Descriptive statistics were calculated. Results were also stratified based on OPO characteristics. RESULTS: Forty-nine (84.5%) of 58 OPOs responded to the survey; 40 (81.6%) of 49 currently perform PLB. This did not vary based on land mass, population, livers discarded, transplanted, donor age, or recipient MELD scores. Donor age, obesity, alcohol abuse, hepatitis serology, liver only donor, imaging results, and transplant center request were the most common indications for PLB in over 80% of OPOs. The median rate of performance is 5% to 10% of donors. Most use interventional radiologists to perform and the donor hospital pathologist/s to interpret PLB. Most OPOs believe PLBs are safe, reliable, useful, and performed often enough. Most say they did not believe they are easy to obtain. Beliefs were mixed regarding accuracy. The topics likely to influence PLB use were utility and accuracy of PLB, and availability of staff to perform PLB. OPOs that perform PLB more often were more likely to have favorable opinions of safety and pathologist availability, and more influenced by safety, reliability, availability, and a national consensus on the use of PLB. CONCLUSIONS: Considerable variability exists in the use of PLB. Additional information on the utility, accuracy, and safety of PLB are needed to optimize its use.

Identifying Potential Ventilator Auto-Triggering Among Organ Procurement Organization Referrals.

CONTEXT: Ventilator auto-trigger is the delivery of an assisted mechanical ventilated breath over the set ventilator frequency in the absence of a spontaneous inspiratory effort and can be caused by inappropriate ventilator trigger sensitivity. Ventilator auto-trigger can be misinterpreted as a spontaneous breath and has the potential to delay or prevent brain death testing and confuse health-care professionals and/or patient families. OBJECTIVE: To determine the frequency of organ donor referrals from 1 Organ Procurement Organization (OPO) that could benefit from an algorithm designed to assist organ recovery coordinators to identify and correct ventilator auto-triggering. DESIGN: This retrospective analysis evaluated documentation of organ donor referrals from 1 OPO in central Texas during the 2013 calendar year that resulted in the withdrawal of care by the patient's family and the recovery of organs. MAIN OUTCOME MEASURES: The frequency of referrals that presented with absent brain stem reflexes except for additional respirations over the set ventilator rate was determined to assess for the need of the proposed algorithm. RESULTS: Documentation of 672 organ procurement organization referrals was evaluated. Documentation from 42 referrals that resulted in the withdrawal of care and 21 referrals that resulted in the recovery of organs were identified with absent brain stem reflexes except for spontaneous respirations on the mechanical ventilator. As a result, an algorithm designed to identify and correct ventilator auto-trigger could have been used 63 times during the 2013 calendar year.