How to counteract the lack of donor tissue in cardiac surgery? Initial experiences with a newly established homograft procurement program.

Homograft heart valves may have significant advantages and are preferred for the repair of congenital valve malformations, especially in young women of childbearing age, athletes and in patients with active endocarditis. A growing problem, however, is the mismatch between tissue donation and the increasing demand. The aim of this paper is to describe the initiation process of a homograft procurement program to attenuate the shortage of organs. A comprehensive description of the infrastructure and procedural steps required to initiate a cardiac and vascular tissue donation program combined with a prospective follow-up of all homografts explanted at our institution. Between January 2020 and May 2022, 28 hearts and 12 pulmonary bifurcations were harvested at our institution and delivered to the European homograft bank. Twenty-seven valves (19 pulmonary valves, 8 aortic valves) were processed and allocated for implantation. The reasons for discarding a graft were either contamination (n = 14), or morphology (n = 13) or leaflet damage (n = 2). Five homografts (3 PV, 2 AV) have been cryopreserved and stored while awaiting allocation. One pulmonary homograft with a leaflet cut was retrieved by bicuspidization technique and awaits allocation, as a highly requested small diameter graft. The implementation of a tissue donation program in cooperation with a homograft bank can be achieved with reasonable additional efforts at a transplant center with an in-house cardiac surgery department. Challenging situations with a potential risk of tissue injury during procurement include re-operation, harvesting by a non-specialist surgeon and prior central cannulation for mechanical circulatory support.

Deceased organ donation activity and efficiency in Switzerland between 2008 and 2017: achievements and future challenges.

BACKGROUND: Various actions have been taken during the last decade to increase the number of organs from deceased donors available for transplantation in Switzerland. This study provides an overview on key figures of the Swiss deceased organ donation and transplant activity between 2008 and 2017. In addition, it puts the evolution of the Swiss donation program's efficiency in relation to the situation in the neighboring countries. METHODS: This study is an analysis of prospective registry data, covering the period from 1 January 2008 to 31 December 2017. It includes all actual deceased organ donors (ADD) in Switzerland. Donor data were extracted from the Swiss Organ Allocation System. The "donor conversion index" (DCI) methodology and data was used for the comparison of donation program efficiency in Switzerland, Germany, Austria, Italy and France. RESULTS: During the study period there were 1116 ADD in Switzerland. The number of ADD per year increased from 91 in 2008 to 145 in 2017 (+ 59%). The reintroduction of the donation after cardiocirculatory death (DCD) program in 2011 resulted in the growth of annual percentages of DCD donors, reaching a maximum of 27% in 2017. The total number of organs transplanted from ADD was 3763 (3.4 ± 1.5 transplants per donor on average). Of these, 48% were kidneys (n = 1814), 24% livers (n = 903), 12% lungs (n = 445), 9% hearts (n = 352) and 7% pancreata or pancreatic islets (n = 249). The donation program efficiency assessment showed an increase of the Swiss DCI from 1.6% in 2008 to 2.7% in 2017 (+ 69%). The most prominent efficiency growth was observed between 2012 and 2017. Even though Swiss donation efficiency increased during the study period, it remained below the DCI of the French and Austrian donation programs. CONCLUSION: Swiss donation activity and efficiency grew during the last decade. The increased donation efficiency suggests that measures implemented so far were effective. The lower efficiency of the Swiss donation program, compared to the French and Austrian programs, may likely be explained by the lower consent rate in Switzerland. This issue should be addressed in order to achieve the goal of more organs available for transplantation.

The use of life-saving extracorporeal membrane oxygenation (ECMO) for pregnant woman with status asthmaticus.

INTRODUCTION: Status asthmaticus can develop into a life-threatening disorder that requires mechanical ventilation. Severe respiratory failure during pregnancy can worsen maternal and fetal outcomes. Previous case studies have demonstrated extracorporeal membrane oxygenation (ECMO) as a life-saving measure for pregnant women with acute respiratory distress syndrome (ARDS) as well as non-pregnant patients with status asthmaticus. CASE STUDY: A 25-year-old woman, who was 5 weeks pregnant, was admitted with status asthmaticus and severe hypercapnic respiratory failure. Despite rescue therapies such as pressure control ventilation with high inspiratory pressures, inhaled beta2 agonists and antimuscarinic drugs, intravenous salbutamol, methylprednisolone and magnesium sulfate, her condition gradually deteriorated. Veno-venous ECMO was initiated for respiratory support and the patient's clinical condition as well as the gas exchange improved within the next few days. ECMO was removed and the patient was extubated after 2 days. Sonography, however, revealed a retrochorial hematoma; the patient was diagnosed with abortus imminens and successfully treated with magnesium substitution and bed rest. Finally, she gave birth to a healthy boy at 38 weeks of gestation. CONCLUSIONS: This is the first case report on the successful use of ECMO in a pregnant woman with severe respiratory insufficiency due to status asthmaticus, who failed to respond to invasive mechanical ventilation and maximum pharmacological treatment. Despite this life-threatening condition, the use of ECMO in our patient has greatly improved the chance of survival for the mother and the baby, who was born without any complications.

Impact of time interval between donor brain death and cold preservation on long-term outcome in lung transplantation.

OBJECTIVES: Brain death (BD) is associated with various systemic responses and a cascade of inflammatory reactions. It is still unknown how the time interval from BD to cold preservation (CP) affects outcome after lung transplantation (LTx). This report investigates the impact of the time interval from BD to CP on long-term outcome in LTx. METHODS: We reviewed 250 consecutive recipients who underwent LTx at our institution between January 2000 and December 2011. In Group I (n = 212), the time interval from BD to CP was <24 h, and in Group II (n = 38) >24 h. Cox proportional hazard regression analysis was performed to determine the risk factors affecting survival. RESULTS: The median time from BD to CP was 18.6 h (range 9-65). The rate of postoperative complications was comparable (P = 0.8). The 30-day mortality rate was 7.5% in Group I and 0% in Group II. The 5-year survival rate was better in Group II [70% (95% CI: 48.5-83.8%)] than in Group I [66% (95% CI: 58.3-72.5%)] without statistical significance (P = 0.3). Intraoperative extracorporeal membrane oxygenation (ECMO) use was identified as a significant risk factor for survival [HR = 1.7, (95% CI: 1.1-2.6), P = 0.01]. CONCLUSION: In our cohort, the time interval from BD to CP had no impact on long-term outcome after LTx.

Noninvasive cardiac output and blood pressure monitoring cannot replace an invasive monitoring system in critically ill patients.

BACKGROUND: Monitoring of cardiac output and blood pressure are standard procedures in critical care medicine. Traditionally, invasive techniques like pulmonary artery catheter (PAC) and arterial catheters are widely used. Invasiveness bears many risks of deleterious complications. Therefore, a noninvasive reliable cardiac output (CO) and blood pressure monitoring system could improve the safety of cardiac monitoring. The aim of the present study was to compare a noninvasive versus a standard invasive cardiovascular monitoring system. METHODS: Nexfin HD is a continuous noninvasive blood pressure and cardiac output monitor system and is based on the development of the pulsatile unloading of the finger arterial walls using an inflatable finger cuff. During continuous BP measurement CO is calculated. We included 10 patients with standard invasive cardiac monitoring system (pulmonary artery catheter and arterial catheter) comparing invasively obtained data to the data collected noninvasively using the Nexfin HD. RESULTS: Correlation between mean arterial pressure measured with the standard arterial monitoring system and the Nexfin HD was r2 = 0.67 with a bias of -2 mmHg and two standard deviations of +/- 16 mmHg. Correlation between CO derived from PAC and the Nexfin HD was r2 = 0.83 with a bias of 0.23 l/min and two standard deviations of +/- 2.1 l/min; the percentage error was 29%. CONCLUSION: Although the noninvasive CO measurement appears promising, the noninvasive blood pressure assessment is clearly less reliable than the invasively measured blood pressure. Therefore, according to the present data application of the Nexfin HD monitoring system in the ICU cannot be recommended generally. Whether such a tool might be reliable in certain critically ill patients remains to be determined.