Ex Situ Left Ventricular Pressure-Volume Loop Analyses for Donor Hearts: Proof of Concept in an Ovine Experimental Model.

Ex situ heart perfusion (ESHP) has emerged as an important strategy to preserve donation after brain death (DBD) and donation after circulatory death (DCD) donor hearts. Clinically, both DBD and DCD hearts are successfully preserved using ESHP. Viability assessment is currently based on biochemical values, while a reliable method for graft function assessment in a physiologic working mode is unavailable. As functional assessment during ESHP has demonstrated the highest predictive value of outcome post-transplantation, this is an important area for improvement. In this study, a novel method for ex situ assessment of left ventricular function with pressure-volume loop analyses is evaluated. Ovine hearts were functionally evaluated during normothermic ESHP with the novel pressure-volume loop system. This system provides an afterload and adjustable preload to the left ventricle. By increasing the preload and measuring end-systolic elastance, the system could successfully assess the left ventricular function. End-systolic elastance at 60 min and 120 min was 2.8 ± 1.8 mmHg/mL and 2.7 ± 0.7 mmHg/mL, respectively. In this study we show a novel method for functional graft assessment with ex situ pressure-loop analyses during ESHP. When further validated, this method for pressure-volume assessments, could be used for better graft selection in both DBD and DCD donor hearts.

Surgical treatment of esophago-tracheobronchial fistulas after esophagectomy.

The aim of this study was to evaluate the surgical treatment of esophago-tracheobronchial fistulas (ETBFs) that occurred after esophagectomy with gastric conduit reconstruction in a tertiary referral center for esophageal surgery. All patients who underwent surgical repair for an ETBF after esophagectomy with gastric conduit reconstruction were included in a tertiary referral center. The primary outcome was successful recovery after surgical treatment for ETBF, defined as a patent airway at 90 days after the surgical fistula repair. Secondary outcomes were details on the clinical presentation, diagnostics, and postoperative course after fistula repair. Between 2007 and 2022, 14 patients who underwent surgical repair for an ETBF were included. Out of 14 patients, 9 had undergone esophagectomy with cervical anastomosis and 5 esophagectomy with intrathoracic anastomosis after which 13 patients had developed anastomotic leakage. Surgical treatment consisted of thoracotomy to cover the defect with a pericardial patch and intercostal flap in 11 patients, a patch without interposition of healthy tissue in 1 patient, and fistula repair via cervical incision with only a pectoral muscle flap in 2 patients. After surgical treatment, 12 patients recovered (86%). Mortality occurred in two patients (14%) due to multiple organ failure. This study evaluated the techniques and outcomes of surgical repair of ETBFs following esophagectomy with gastric conduit reconstruction in 14 patients. Treatment was successful in 12 patients (86%) and generally consisted of thoracotomy and coverage of the defect with a bovine pericardial patch followed by interposition with an intercostal muscle.

Circadian rhythms in pump parameters of patients on contemporary left ventricular assist device support.

BACKGROUND: Algorithms to monitor pump parameters are needed to further improve outcomes after left ventricular assist device (LVAD) implantation. Previous research showed a restored circadian rhythm in pump parameters in patients on HeartWare (HVAD) support. Circadian patterns in HeartMate3 (HM3) were not studied before, but this is important for the development of LVAD monitoring algorithms. Hence, we aimed to describe circadian patterns in HM3 parameters and their relation to patterns in heart rate (HR). METHODS: 18 HM3 patients were included in this study. HM3 data were retrieved at a high frequency (one sample per 1 or 2 h) for 1-2 weeks. HR was measured using a wearable biosensor. To study overall patterns in HM3 parameters and HR, a heatmap was created. A 24-h cosine was fitted on power and HR separately. The relationship between the amplitude of the fitted cosines of power and HR was calculated using Spearman correlation. RESULTS: A lower between patient variability was found in power compared with flow and PI. 83% of the patients showed a significant circadian rhythmicity in power (p < 0.001-0.04), with a clear morning increase. All patients showed significant circadian rhythmicity in HR (p < 0.001-0.02). The amplitudes of the circadian rhythm in power and HR were not correlated (Spearman correlation of 0.32, p = 0.19). CONCLUSIONS: A circadian rhythm of pump parameters is present in the majority of HM3 patients. Higher frequency pump parameter data should be collected, to enable early detection of complications in the future development of predictive algorithms.

Radiological Screening Methods in Deceased Organ Donation: An Overview of Guidelines Worldwide.

Organ transplantation is performed worldwide, but policies regarding donor imaging are not uniform. An overview of the policies in different regions is missing. This study aims to investigate the various protocols worldwide on imaging in deceased organ donation. An online survey was created to determine the current policies. Competent authorities were approached to fill out the survey based on their current protocols. In total 32 of the 48 countries approached filled out the questionnaire (response rate 67%). In 16% of the countries no abdominal imaging is required prior to procurement. In 50%, abdominal ultrasound (US) is performed to screen the abdomen and in 19% an enhanced abdominal Computed Tomography (CT). In 15% of the countries both an unenhanced abdominal CT scan and abdominal US are performed. In 38% of the countries a chest radiographic (CXR) is performed to screen the thorax, in 28% only a chest CT, and in 34% both are performed. Policies regarding radiologic screening in deceased organ donors show a great variation between different countries. Consensus on which imaging method should be applied is missing. A uniform approach will contribute to quality and safety, justifying (inter)national exchange of organs.

Waiting list mortality and the potential of donation after circulatory death heart transplantations in the Netherlands.

BACKGROUND: With more patients qualifying for heart transplantation (HT) and fewer hearts being transplanted, it is vital to look for other options. To date, only organs from brain-dead donors have been used for HT in the Netherlands. We investigated waiting list mortality in all Dutch HT centres and the potential of donation after circulatory death (DCD) HT in the Netherlands. METHODS: Two different cohorts were evaluated. One cohort was defined as patients who were newly listed or were already on the waiting list for HT between January 2013 and December 2017. Follow-up continued until September 2018 and waiting list mortality was calculated. A second cohort of all DCD donors in the Netherlands (lung, liver, kidney and pancreas) between January 2013 and December 2017 was used to calculate the potential of DCD HT. RESULTS: Out of 395 patients on the waiting list for HT, 196 (50%) received transplants after a median waiting time of 2.6 years. In total, 15% died while on the waiting list before a suitable donor heart became available. We identified 1006 DCD donors. After applying exclusion criteria and an age limit of 50 years, 122 potential heart donors remained. This number increased to 220 when the age limit was extended to 57 years. CONCLUSION: Waiting list mortality in the Netherlands is high. HT using organs from DCD donors has great potential in the Netherlands and could lead to a reduction in waiting list mortality. Cardiac screening will eventually determine the true potential.

Listing criteria for heart transplantation in the Netherlands.

The updated listing criteria for heart transplantation are presented on behalf of the three heart transplant centres in the Netherlands. Given the shortage of donor hearts, selection of those patients who may expect to have the greatest benefit from a scarce societal resource in terms of life expectancy and quality of life is inevitable. The indication for heart transplantation includes end-stage heart disease not remediable by more conservative measures, accompanied by severe physical limitation while on optimal medical therapy, including ICD/CRT­D. Assessment of this condition requires cardiopulmonary stress testing, prognostic stratification and invasive haemodynamic measurements. Timely referral to a tertiary centre is essential for an optimal outcome. Chronic mechanical circulatory support is being used more and more as an alternative to heart transplantation and to bridge the progressively longer waiting time for heart transplantation and, thus, has become an important treatment option for patients with advanced heart failure.

Dilemmas concerning heart procurement in controlled donation after circulatory death.

With an expanding population at risk for heart failure and the resulting increase in patients admitted to the waiting list for heart transplantation, the demand of viable organs exceeds the supply of suitable donor hearts. Use of hearts after circulatory death has reduced this deficit. Two primary techniques for heart procurement in circulatory death donors have been described: direct procurement and perfusion and thoraco-abdominal normothermic regional perfusion. While the former has been accepted as an option for heart procurement in circulatory death donors, the latter technique has raised some ethical questions in relation to the dead donor rule. In this paper we discuss the current dilemmas regarding these heart procurement protocols in circulatory death donors.

Residual cardiovascular risk reduction guided by lifetime benefit estimation in patients with symptomatic atherosclerotic disease: effectiveness and cost-effectiveness.

AIMS: To determine the (cost)-effectiveness of blood pressure lowering, lipid-lowering, and antithrombotic therapy guided by predicted lifetime benefit compared to risk factor levels in patients with symptomatic atherosclerotic disease. METHODS AND RESULTS: For all patients with symptomatic atherosclerotic disease in the UCC-SMART cohort (1996-2018; n = 7697) two treatment strategies were compared. The lifetime benefit-guided strategy was based on individual estimation of gain in cardiovascular disease (CVD)-free life with the SMART-REACH model. In the risk factor-based strategy, all patients were treated the following: low-density lipoprotein cholesterol (LDL-c) < 1.8 mmol/L, systolic blood pressure <140 mmHg, and antithrombotic medication. Outcomes were evaluated for the total cohort using a microsimulation model. Effectiveness was evaluated as total gain in CVD-free life and events avoided, cost-effectiveness as incremental cost-effectivity ratio (ICER). In comparison to baseline treatment, treatment according to lifetime benefit would lead to an increase of 24 243 CVD-free life years [95% confidence interval (CI) 19 980-29 909] and would avoid 940 (95% CI 742-1140) events in the next 10 years. For risk-factor based treatment, this would be an increase of 18 564 CVD-free life years (95% CI 14 225-20 456) and decrease of 857 (95% CI 661-1057) events. The ICER of lifetime benefit-based treatment with a treatment threshold of ≥1 year additional CVD-free life per therapy was €15 092/QALY gained and of risk factor-based treatment €9933/QALY gained. In a direct comparison, lifetime benefit-based treatment compared to risk factor-based treatment results in 1871 additional QALYs for the price of €36 538/QALY gained. CONCLUSION: Residual risk reduction guided by lifetime benefit estimation results in more CVD-free life years and more CVD events avoided compared to the conventional risk factor-based strategy. Lifetime benefit-based treatment is an effective and potentially cost-effective strategy for reducing residual CVD risk in patients with clinical manifest vascular disease.

Immediate impact of COVID-19 on transplant activity in the Netherlands.

The rapid emergence of the COVID-19 pandemic is unprecedented and poses an unparalleled obstacle in the sixty-five year history of organ transplantation. Worldwide, the delivery of transplant care is severely challenged by matters concerning - but not limited to - organ procurement, risk of SARS-CoV-2 transmission, screening strategies of donors and recipients, decisions to postpone or proceed with transplantation, the attributable risk of immunosuppression for COVID-19 and entrenched health care resources and capacity. The transplant community is faced with choosing a lesser of two evils: initiating immunosuppression and potentially accepting detrimental outcome when transplant recipients develop COVID-19 versus postponing transplantation and accepting associated waitlist mortality. Notably, prioritization of health care services for COVID-19 care raises concerns about allocation of resources to deliver care for transplant patients who might otherwise have excellent 1-year and 10-year survival rates. Children and young adults with end-stage organ disease in particular seem more disadvantaged by withholding transplantation because of capacity issues than from medical consequences of SARS-CoV-2. This report details the nationwide response of the Dutch transplant community to these issues and the immediate consequences for transplant activity. Worrisome, there was a significant decrease in organ donation numbers affecting all organ transplant services. In addition, there was a detrimental effect on transplantation numbers in children with end-organ failure. Ongoing efforts focus on mitigation of not only primary but also secondary harm of the pandemic and to find right definitions and momentum to restore the transplant programs.

Surgery promotes implantation of disseminated tumor cells, but does not increase growth of tumor cell clusters.

INTRODUCTION: Local recurrence and peritoneal dissemination is common after intentionally curative resection of colorectal carcinoma. It is not yet clear which mechanisms stimulate post-operative intra-abdominal tumor development. Enhanced adhesion or growth of tumor cells and/or post-operative immuno suppression may influence tumor recurrence. AIMS OF THE STUDY: In the present study, we evaluated effects of local and remote surgery on intra-abdominal tumor development. MATERIALS AND METHODS: A standardized intra-abdominal trauma was inflicted by rubbing both uterus horns in laparotomy groups, while a dorsolateral thoracotomy was performed in thoracotomy groups (on day -1, 0, or +3). To induce tumor development rats were injected intra-peritoneally with the coloncarcinoma cell line CC531s on day 0 and evaluated after 21 days. RESULTS: Rats undergoing laparotomy and injection on day 0 showed significantly higher tumorload than control rats (195 +/- 20 vs. 47 +/- 29, P < 0.001). When a laparotomy was performed, the day before tumor inoculation even higher tumorload was seen (245 +/- 37 vs. 195 +/- 20, P < 0.01). Strikingly, performing a thoracotomy on the day before or on the same day as tumor inoculation resulted in enhanced tumorload compared to controls as well (135 +/- 84 vs. 47 +/- 29; P < 0.001 and 88 +/- 38 vs. 47 +/- 29; P < 0.02, respectively). Either laparotomy or thoracotomy 3 days after tumor cell inoculation did not affect growth of pre-existing tumor cell clusters. CONCLUSIONS: The (post) surgical intra-peritoneal microenvironment enhances successful implantation of spilled tumor cells, whereas growth of adhered tumor cell clusters is not affected. The inflammatory response as a result of remote surgery promotes successful tumor development as well.