Non-heart-beating Donors Lungs Research Articles

The airflow and cooling characteristics in the airway of NHBD lung with hypothermic ventilation

Hypothermic ventilation through trachea can cool Non-heart beating donor (NHBD) lungs noninvasively in vivo, thus avoiding warm ischemic damage. However, previous experimental studies with large lungs have shown poor cooling effect in bronchial terminal of NHBD lungs. To investigate the airflow and cooling characteristics of this process, a physiologically realistic upper airway model was established. In addition, droplet spraying was considered to enhance the heat transfer during the cooling process. The results show that the irregular geometry of realistic airway will lead to non-uniformity distribution of internal flow and temperature, and the local cooling effect in different regions is related to the velocity distribution. The secondary flow at the bifurcation can forcibly strengthen the heat exchange between the cold air and the hot air in the nearby low-speed area. Increasing the ventilation flow will strengthen the turbulence and heat exchange in the airway, so as to improve the overall cooling effect. The synergistic effect of cold air and droplet spraying can enhance the cooling effect in the airway. And large droplets (i.e. 10 μm) are conducive to the cooling enhancement of the central airway, while small droplets (i.e. 2 μm) are conducive to the cooling of the distal bronchus.

The protective effect of hypercapnia on ischemia-reperfusion injury in lungs

Lifesaving therapy for patients with end-stage lung disease is lung transplantation. However, there are not enough available donors. A relatively new method of transplantation from non-heart-beating donors (NHBDs) allows the treatment of the lung outside the body and could increase the number of suitable lungs. We have focused on hypercapnic ventilation, which has the possibility of reducing reactive oxygen species damage.We used four experimental and two control groups of adult rats. Each experimental group underwent the protocol of NHBD lung harvesting. The lungs were than perfused in an ex vivo model and we measured weight gain, arterial-venous difference in partial pressure of oxygen and perfusion pressure.We observed that hypercapnic ventilation during reperfusion reduces the development of pulmonary oedema and has a protective effect on the oxygen transport ability of the lungs after warm ischemia. The effect of CO2 on pulmonary oedema and on oxygen transport ability after warm ischemia could be of clinical importance for NHBD transplantation.

Emergency medical services knowledge and attitudes about non-heart-beating donors: Effect of an educational intervention

More than 750,000 people die of sudden death each year, and many are potential non-heart-beating donors (NHBDs) for lung transplant. Although critical, the role of emergency medical services (EMS) personnel in assisting with recovery of NHBD lungs has not been studied. The purpose of this study was to assess knowledge of and attitudes about NHBDs among EMS personnel, evaluate the extent to which knowledge and personal experience with organ donation is associated with attitude, and ascertain the effectiveness of an intervention designed to teach EMS professionals about NHBDs. EMS professionals (n = 361) completed measures of knowledge of and attitudes about NHBDs and then watched a presentation by a transplant doctor about traditional organ donation, NHBDs, and transplantation. Participants were able to ask questions during and after the presentation. Participants completed the measures again 3 months later. EMS professionals had a high rate of personal experience with organ donation and positive attitudes toward traditional organ donation. However, they showed lack of knowledge about NHBDs and felt less skilled in being part of the NHBD process, consistent with knowledge scores. The educational intervention was somewhat effective in improving knowledge about NHBDs. Scores improved significantly on 5 of 13 items. Lung recovery from NHBDs offers the potential of a very large supply for transplantation. This research suggests that with additional training, EMS professionals may be willing to be part of a NHBD recovery team.

The Effects of Hydrogen Gas Inhalation On Non-Heart-Beating Donor Lung During Ex Vivo Lung Perfusion.

Purpose: The shortage of donor lung is a limiting factor in lung transplantation (LTx). In order to resolve this problem, non-heart-beating donor (NHBD) lungs are evaluated in ex vivo lung perfusion (EVLP) system prior to LTx. In this study, the effects of hydrogen gas inhalation on NHBD lungs were investigated during EVLP. Methods: Ten 40kg female pigs were randomly divided into control (n=5) and study group (n=5). After cardiac arrest and one hour of warm ischemic injury, the lungs were harvested after flushing with Perfadex solution, and the lungs assessed in the EVLP system for 4 hours. Steen solution was used as perfusate. During EVLP, the lungs were ventilated in the control group with room air (0.2 of FiO2), and with 2% hydrogen gas in the study group. Oxygen capacity, pulmonary vascular resistance and peak airway pressure were measured every hour for 4 hours during EVLP. After the EVLP, lung specimens were excised for measurement of p38, JNK, and ERK 1/2 phosphorylation, and the expression of IL-1ß, IL-6, IL-8, and TNF-α. Pathologic evaluation was performed using lung injury severity score after H & E stain, and wet/dry ratio was examined. Results: Oxygen capacity in the study group was higher than the control group but did not show a significant difference (p = 0.0862). However, pulmonary vascular resistance (p = 0.0111) and peak airway pressure (p = 0.0189) were significantly lower in the study group. The extents of phosphorylation of p38, JNK, and ERK 1/2 were lower in the study group, but did not show statistically significant difference. The expression of IL-1ß (p = 0.0317), IL-6 (p = 0.0159), IL-8 (p = 0.0195), and TNF-α (p = 0.0159) were all significantly lower in the study group. Lung injury score (p = 0.0358) and wet/dry ratio (p = 0.040) were also lower in the study group.Conclusion: Inhalation of hydrogen gas in NHBD lungs during EVLP may improve the function of damaged lungs, and might possibly increase the utilization of NHBD lungs.

Effects of exogenous surfactant on the non‐heart‐beating donor lung graft in experimental lung transplantation – a stereological study

The use of non-heart-beating donor (NHBD) lungs may help to overcome the shortage of lung grafts in clinical lung transplantation, but warm ischaemia and ischaemia/reperfusion injury (I/R injury) resulting in primary graft dysfunction represent a considerable threat. Thus, better strategies for optimized preservation of lung grafts are urgently needed. Surfactant dysfunction has been shown to contribute to I/R injury, and surfactant replacement therapy is effective in enhancing lung function and structural integrity in related rat models. In the present study we hypothesize that surfactant replacement therapy reduces oedema formation in a pig model of NHBD lung transplantation. Oedema formation was quantified with (SF) and without (non-SF) surfactant replacement therapy in interstitial and alveolar compartments by means of design-based stereology in NHBD lungs 7 h after cardiac arrest, reperfusion and transplantation. A sham-operated group served as control. In both NHBD groups, nearly all animals died within the first hours after transplantation due to right heart failure. Both SF and non-SF developed an interstitial oedema of similar degree, as shown by an increase in septal wall volume and arithmetic mean thickness as well as an increase in the volume of peribron-chovascular connective tissue. Regarding intra-alveolar oedema, no statistically significant difference could be found between SF and non-SF. In conclusion, surfactant replacement therapy cannot prevent poor outcome after prolonged warm ischaemia of 7 h in this model. While the beneficial effects of surfactant replacement therapy have been observed in several experimental and clinical studies related to heart-beating donor lungs and cold ischaemia, it is unlikely that surfactant replacement therapy will overcome the shortage of organs in the context of prolonged warm ischaemia, for example, 7 h. Moreover, our data demonstrate that right heart function and dysfunctions of the pulmonary vascular bed are limiting factors that need to be addressed in NHBD.

Surfactant application in experimental lung transplantation

Non-heart-beating donor (NHBD) utilization can significantly increase the limited donor lung pool. However, optimal preservation of organ function is crucial as the development of ischemia/reperfusion injury (IRI) can result in severe surfactant inactivation. Exogenic surfactant application is effective in prevention and therapy of IRI. Studies on optimal timing of Curosurf, including application in NHBDs, have not been done, but could help to optimize NHBD lung transplantation. The extracorporeal screening model (ESM) included rat lungs (Sprague-Dawley, n = 5/group) preserved with Perfadex. In 3 test groups, Curosurf was administered before flush preservation (T1), after 4-hour ischemia (T2) or during reperfusion (T3). Results after extracorporeal reperfusion were compared with controls. The transplantation model (TM) consisted of asystolic pigs (n = 5/group) ventilated for 7 hours with warm ischemia (WIT, Groups 1 and 2). In Group 2, 100 mg/kg BW Curosurf was bronchoscopically administered before preservation. After 3-hour cold storage, left lung transplantation was performed and data were compared with sham control data (Group 3). For the ESM, T1 lung oxygenation (SurfT1 167±47.4 mm Hg) was superior to others (SurfT2 47.3±15.3 mm Hg, SurfT3 77.2±48.8 mm Hg, controls 65.5±46.2 mm Hg; p<0.02). Stereology demonstrated poorer intra-alveolar edema formation in controls (1.86±2.53% of parenchyma) compared with surfactant-treated lungs (<0.02% of parenchyma) (p<0.02). Intra-alveolar erythrocyte sequestration as an indicator of vascular leakage was significantly lower in T1 lungs (0.15±0.12% of parenchyma) compared with all other groups (>0.74% of parenchyma). For TM, mortality was 80% in the untreated group and 100% in the Curosurf group, suggesting that a 7-hour WIT is above the limit for NHBD utilization. Donor lung pre-treatment with endobronchial pre-preservation Curosurf offers optimal preservation quality when compared with post-ischemic application or during reperfusion and results in improved functional outcome when compared with controls. Expensive NHBD pre-treatment with Curosurf cannot improve poor allograft outcome after extended WIT and should therefore not be considered. Seven-hour WIT seems generally to be above the limits for use in NHBD lung donors.

Protective effects of ischemic postconditioning on non-heart-beating donor in rat lung transplantation

To explore the protective effects of ischemic postconditioning on non-heart-beating donor (NHBD) in rat NHBD lung transplantation model. Forty Sprague-Dawley rats were randomized into the ischemic postconditioning group (IPO group) and the control group (C group), 10 pairs in each group in which left lung orthotopic transplantations from NHBDs were done with " two-cuff-one-stent technique". In the C group, perfusion was resumed by declamping pulmonary artery immediately after transplantation, whereas in the IPO group, 5 cycles of 1-min reperfusion and 1-min reocclusion of pulmonary artery were applied as postcontioning before full recovery of perfusion. Compared with the C group, water content of donor lungs was lower and pathological changes were milder in the IPO group, meanwhile compliance, structure and function of donor lungs were better preserved. Furthermore, the expression of cell apoptosis and MDA content in donor lungs were lower in the IPO group, while SOD content was higher. Ischemic postconditioning can reduce ischemic reperfusion injury of NHBD lung transplantation and preserve the structure and function of donor lungs. It can inhibit lipid peroxidation and cell apoptosis in NHBD lungs after transplantation.

Protective Effect of Hypercapnia on Ischemia – Reperfusion Injury in Lungs Retrieved from Non‐heart‐beating Donors

Lungs retrieved from non‐heart‐beating donors (NHBD) might alleviate the shortage of suitable organs for transplantation. Since hypercapnia has protective effect on free radical damage, in present study we investigated a possible protective effect of hypercapnic ventilation during reperfusion in lungs retrieved from NHBD.Experimental rats underwent the protocol of NHBD lung harvesting: 90 minutes of warm ischemia after pentobarbital euthanasia followed by 60 min of cold ischemia (12°C). Then we measured perfusion pressure, lung weight gain and arterio ‐ venous difference in O2 partial pressure in isolated, Salt solution + Ficol perfused lungs. In controls, lungs were harvested immediately after euthanasia.We used four groups of rats: Control group – C Control group, isolated lungs ventilated with hypercapnic gas (10%CO2) ‐ CH Experimental rats – warm + cold ischemia – W Experimental rats, hypercapnic ventilation – WH Warm ischemia deteriorates lung functions (W vs C). We found that hypercapnic ventilation reduced pulmonary edema (WH vs. W) and improved oxygen transport ability (WH vs. W, no difference in WH vs. C). We conclude that hypercapnia prevents ischemia – reperfusion injury in NHBD lungs.Supported by Czech Science Foundation, GACR P303/10/P343 and GACR 305/08/0108

91 Reconditioning of Lungs from Non-Heart-Beating Donors with Normothermic Ex Vivo Lung Perfusion

Purpose To resolve the shortage of donor lungs, the use of non-heart-beating donors (NHBD) has come into practice. An ideal method of preservation that can improve the quality of NHBD lungs has been investigated. Normothermic ex vivo lung perfusion (EVLP) enables organ viability assessment before transplantation. In this study, we investigated whether NHBD lungs can be resuscitated after warm ischemia by normothermic EVLP. Methods and Materials Four hours after cardiac arrest, the beagles were allocated into 2 groups (n=6 each): static cold storage (SCS) or normothermic EVLP using STEEN solution for 3.5 h. The physiological lung functions were evaluated during normothermic EVLP. In both groups, left lungs were then transplanted and reperfused for 4 h to investigate posttransplant lung functions. Results In each group, one beagle has died due to severe pulmonary edema after 2 h of reperfusion. Lung oxygenation significantly improved with normothermic EVLP (p Conclusions Normothermic ex vivo lung perfusion could resuscitate NHBD lungs injured by 4 h of warm ischemia.

90 Clinical Lung Transplantation after Ex Vivo Evaluation of Uncontrolled Non Heart-Beating Donors Lungs: Initial Experience

<h3>Purpose</h3> To describe the first series of Ex Vivo evaluations of human lungs from Maastricht type I non heart-beating donors and clinical transplantations with these organs. <h3>Methods and Materials</h3> Eight potential male donors entered the non heart-beating protocol after sudden cardiac arrest in the street and unsuccessful resuscitation. Bipulmonary blocks were topically cooled and flushed with antegrade and retrograde cold Perfadex. A normothermic Ex Vivo evaluation was initiated, perfusing the lungs with a flow 40% of the estimated cardiac output and protectively ventilating after reaching 32°C. Oxygenation tests were performed hourly. Three criteria were to be met for acceptance: ΔpO2(difference between atrium and pulmonary artery pO2) over 400mmHg, stable or improving evaluation data and surgeon approval of lung appearance and procedure. <h3>Results</h3> Ex Vivo evaluation was correctly perfomed in all cases. Average perfusion time was 273min. Four blocks did not pass the evaluation because of low oxygenation and declining compliance. Bronchiolitis, diffuse emphysema and bone marrow emboli were found in the pre-Ex Vivo pathology analyses of rejected lungs. Four blocks passed the evaluation after an average time of perfusion of 270min. The mean ΔpO2 was 461mmHg and the mean compliance was 87.2mlL/cmH2O with a tendency to increase in each evaluation. Acceptable blocks were cold preserved until implantation. Four bilateral lung transplantations were performed (3 emphysema, 1 bronchiectasis) with a total "out of the body" time of 15h19m and 17h35m for first and second lung. There were no cases of grade 3 PGD (31.6% PGD=0; 10.5% PGD=1) Two patients died of non-Ex Vivo related causes after 92 and 122 days. Two patients are alive and well after 204 and 333 days, with no signs of BOS. <h3>Conclusions</h3> Ex vivo evaluation of uncontrolled non-heart beating donor-lungs enables us to ensure an optimal function under physiological conditions before clinical implantation and promises a more widespread use of this kind of donors in the future.

Non-heart-beating donation in Spain

The aim of our study was to describe our protocol of non-heart-beating-donor (NHBD) lung transplantation and discuss data regarding the situation of NHBD and lung transplantation in Spain. Experimental work regarding NHBD led our National Organization of Transplants to develop several working groups with the objective of investigating the possibility of using uncontrolled NHBD in our country. This turned into a flexible and useful legal mechanism that allowed immediate judicial permission to preserve-and harvest-those organs. Several harvesting programs for mainly abdominal organs (kidney and liver) started in Spain during the late 1980s, with good mid-term results. The collaboration between two hospitals in Madrid-Hospital Clinico San Carlos and Hospital Puerta de Hierro as transplantation hospital-led to the development of a successful NHBD lung program for uncontrolled donors that is a pioneer in the world. In Spain, donation after cardiac arrest represents 6.7% of all transplants, mainly from types I (dead on arrival) and II (unsuccessful resuscitation) donors. NHBD for lung transplantation is concentrated in Madrid, with approximately 60 potential NHBDs per year. With this additional source of organs we have so far been able to perform 32 lung transplantations, which represents an increase of 13% of our annual transplantation rates. NHBD is no longer just a promising source of organs for lung transplantations, it is a real one. We hope that in the near future many other units will develop similar protocols to improve the use of these grafts and decrease the mortality rate among those on the waiting lists.

Nitric Oxide Ventilation of Rat Lungs from Non-Heart-Beating Donors Improves Posttransplant Function

Lungs from non-heart-beating donors (NHBDs) would enhance the donor pool. Ex vivo perfusion and ventilation of NHBD lungs allows functional assessment and treatment. Ventilation of rat NHBD lungs with nitric oxide (NO) during ischemia, ex vivo perfusion and after transplant reduced ischemia-reperfusion injury (IRI) and improved lung function posttransplant. One hour after death, Sprague-Dawley rats were ventilated for another hour with either 60% O2 or 60% O2/40 ppm NO. Lungs were then flushed with 20-mL cold Perfadex, stored cold for 1 h, perfused in an ex vivo circuit with Steen solution and warmed to 37 degrees C, ventilated 15 min, perfusion-cooled to 20 degrees C, then flushed with cold Perfadex and stored cold. The left lung was transplanted and ventilated separately. Recipients were sacrificed after 1 h. NO-ventilation was associated with significantly reduced wet:dry weight ratio in the ex vivo circuit, better oxygenation, reduced pulmonary vascular resistance, increased lung tissue levels of cGMP, maintained endothelial NOS eNOS, and reduced increases in tumor necrosis factor alpha (TNF-alpha) and inducible nitric oxide synthase (iNOS). NO-ventilation had no effect on MAP kinases or NF-kappaB activation. NO administration to NHBDs before and after lung retrieval may improve function of lungs from NHBDs.

The mode of death in the non-heart-beating donor has an impact on lung graft quality☆☆☆

We hypothesised that the agonal phase prior to cardiac death may negatively influence the quality of the pulmonary graft recovered from non-heart-beating donors (NHBDs). Different modes of death were compared in an experimental model. Non-heparinised pigs were divided into three groups (n=6 per group). Animals in group I [FIB] were sacrificed by ventricular fibrillation resulting in immediate circulatory arrest. In group II [EXS], animals were exsanguinated (45+/-11 min). In group III [HYP], hypoxic cardiac arrest (13+/-3 min) was induced by disconnecting the animal from the ventilator. Blood samples were taken pre-mortem in HYP and EXS for measurement of catecholamine levels. After 1 h of in situ warm ischaemia, unflushed lungs were explanted and stored for 3 h (4 degrees C). Left lung performance was then tested during 60 min in our ex vivo reperfusion model. Total protein concentration in bronchial lavage fluid was measured at the end of reperfusion. Pre-mortem noradrenalin (mcg l(-1)) concentration (baseline: 0.03+/-0) increased to a higher level in HYP (50+/-8) vs EXS (15+/-3); p=0.0074. PO(2) (mmHg) at 60 min of reperfusion was significantly worse in HYP compared to FIB (445+/-64 vs 621+/-25; p<0.05), but not to EXS (563+/-51). Pulmonary vascular resistance (dynes s cm(-5)) was initially higher in EXS (p<0.001) and HYP (NS) vs FIB (15824+/-5052 and 8557+/-4933 vs 1482+/-61, respectively) but normalised thereafter. Wet-to-dry weight ratio was higher in HYP compared to FIB (5.2+/-0.3 vs 4.7+/-0.2, p=0.041), but not to EXS (4.9+/-0.2). Total protein (g l(-1)) concentration was higher, although not significant in HYP and EXS vs FIB (18+/-6 and 13+/-4 vs 4.5+/-1.3, respectively). Pre-mortem agonal phase in the NHBD induces a sympathetic storm leading to capillary leak with pulmonary oedema and reduced oxygenation upon reperfusion. Graft quality appears inferior in NHBD lungs when recovered in controlled (HYP) vs uncontrolled (EXS and FIB) setting.

Detection of bronchial function of NHBD lung following one-h warm ischemia by organ bath model

This study investigated the feasibility and effects of organ bath to be used for detection of bronchial function of non-heart-beating donor (NHBD) lung after 1-h warm ischemia. Sixteen Swedish pigs were divided into two groups randomly: heart-beating donor (HBD) group and NHBD with 1-h warm ischemia (NHBD-1 h) group. The bronchial rings whose lengths and inner diameters were both 1.5 mm were obtained from isolated left lungs of all the pigs. Acetylcholine, arachidonic acid natrium and papaverine were used to test and compare the contractile and relaxant function of bronchial smooth muscles and epithelium-dependent relaxation (EpiDR) response between HBD and NHBD-1 h groups. The results showed that there was no significant difference in the values of bronchial precontraction between HBD and NHBD-1 h groups (5.18+/-0.07 vs 5.10+/-0.11 mN, P>0.05). No significant difference in the values of EpiDR responses between HBD and NHBD-1 h groups (1.26+/-0.05 vs 1.23+/-0.07 mN, P>0.05) was observed either. During the process of EpiDR induction, the rings had no spontaneous relaxation in two groups. In addition, papaverine solution completely relaxed the bronchial smooth muscles of all bronchial rings. It was concluded that after warm ischemia for 1 h, the contractile and relaxant abilities of bronchial smooth muscles, and the epithelium-dependent adjustment both kept intact. Organ bath model could be a liable and scientific way to evaluate the bronchial function of NHBD lung.

Pre-arrest Administration of the Cell-permeable Free Radical Scavenger Tempol Reduces Warm Ischemic Damage of Lung Function in Non–Heart-beating Donors

Lungs retrieved from non-heart-beating donors (NHBDs) may alleviate the shortage of suitable organs for transplantation. The critical point is the preservation of lungs during warm ischemia, when severe damage is caused by free radicals. We investigated the effect of ventilation, pre-arrest administration of heparin, and the cell-permeable free radical scavenger, tempol, on the function of NHBD grafts. Six experimental and two control groups (n = 6 per group) were established. All experimental groups underwent a protocol of NHBD lung harvesting, which included 1 hour of warm ischemia after pentobarbital euthanasia followed by 90 minutes of cold ischemia. The groups were constructed as follows: Group An-non-ventilated during warm ischemia, no heparin; Group Av-room-air ventilated during warm ischemia, no heparin; Group Hn-non-ventilated, heparin added pre-arrest; Group Hv-ventilated, heparin; Group Tn-non-ventilated, heparin and tempol added pre-arrest; Group Tv-ventilated, tempol, heparin; Group Ac-control group, no warm and cold ischemia, lungs harvested immediately after euthanasia; and Group Tc-controls with tempol added pre-arrest. The lungs were then perfused ex vivo and the perfusion pressure, lung weight and arteriovenous difference in oxygen partial pressure were measured. We found that room-air ventilation during warm ischemia caused severe pulmonary edema during reperfusion. Heparinization prevented an increase in perfusion pressure and ameliorated the oxygen transport ability. Pre-arrest administration of tempol prevented edema formation after ventilation during warm ischemia and had a positive effect on the oxygen transport ability of the lungs. The free radical scavenger tempol, which has a very good ability to permeate biologic membranes, contributes to better preservation of lungs retrieved from NHBDs.

Results of Clinical Lung Transplant From Uncontrolled Non-Heart-Beating Donors

The scarcity of grafts for lung transplant and the growing number of candidates expecting an organ has led to an increase of deaths in patients waiting for lung transplantation. Non-heart-beating donors (NHBD) represent a promising source of grafts for those who are involved in clinical lung transplantation. We present the results of our series of 17 out-of-hospital NHBD lung transplantations performed since 2002. We have collected data from 17 donors and recipients involved in NHBD lung transplants since 2002, as well as data referring to the type of procedure and peri-operative events. We describe the incidence of post-operative complications with special attention to primary graft disfunction (PGD), bronchial healing, bronchiolitis obliterans syndrome (BOS), and survival. We used Kaplan-Meier method to obtain the survival curve. G2-G3 PGD was reported in 9 patients (53%), with a complete restoration of the partial pressure of arterial oxygen/fraction of inspired oxygen ratio in 170 hours for G2 and 168 hours for G3. There were no deaths directly related to PGD. Acute rejection was detected in 7 patients (41%), 4 of which exceeded grade 1. The incidence of BOS after transplantation was 1 (7%) of 14 patients during the first year, 2 (11%) of 9 in the second year, and 2 (50%) of 4 in the third year. Hospital mortality rate was 17%. The survival rates were 82% at 3 months, 69%, at 1 year, and 58% at 3 years. Mid-term results confirm the adequacy of uncontrolled NHBD as a promising complementary source of lung donors for clinical transplant.

Endobronchial Donor Pre-Treatment With Ventavis: Is a Second Administration During Reperfusion Beneficial to Optimize Post-Ischemic Function of Non-Heart Beating Donor Lungs?

Lung retrieval from non-heart-beating donors (NHBD) has been introduced into clinical practice successfully. However, because of potentially deleterious effects of warm ischemia on microvascular integrity, use of NHBD lungs is limited by short tolerable time periods before preservation. Recently, improvement of NHBD graft function was demonstrated by donor pre-treatment using aerosolized Ventavis (Schering Inc., Berlin, Germany). Currently, there is no information whether additional application of this approach in reperfusion can further optimize immediate graft function. Asystolic pigs (n = 5/group) were ventilated for 180-min of warm ischemia (groups 1-3). In groups 2 and 3, 100 microg Ventavis were aerosolized over 30-min using an ultrasonic nebulizer (Optineb). Lungs were then retrogradely preserved with Perfadex and stored for 3-h. After left lung transplantation and contralateral lung exclusion, grafts were reperfused for 6-h. Only in group 3, another dose of 100 microg Ventavis was aerosolized during the first 30-min of reperfusion. Hemodynamics, pO2/FiO2 and dynamic compliance were monitored continuously and compared to controls. Intraalveolar edema was quantified stereologically, and extravascular-lung-water-index (EVLWI) was measured. Statistics comprised ANOVA analysis with repeated measurements. Dynamic compliance was significantly lower in both Ventavis groups, but additional administration did not result in further improvement. Oxygenation, pulmonary hemodynamics, EVLWI and intraalveolar edema formation were comparable between groups. Alveolar deposition of Ventavis in NHBD lungs before preservation significantly improves dynamic lung compliance and represents an important strategy for improvement of preservation quality and expansion of warm ischemic intervals. However, additional application of this method in early reperfusion is of no benefit.

Tempol Reduces Warm Ischemic Damage of Lung Functions In Non‐Heart‐Beating Donors if Added Pre‐arrestly but Doesn’t Have any Protective Effect on Ischemia – Reperfusion Injury

Lungs retrieved from non-heart-beating donors (NHBD) may alleviate the critical shortage of suitable organs for transplantation. We tested the role of cell permeable reactive oxygen species scavenger – Tempol – in protection of warm ischemic and reperfusion injury of lung functions in experimental model of NHBD. We measured perfusion pressure, weight gain and arterio - venous difference in O2 partial pressure in Salt solution + Ficol perfused lungs isolated from Wistar rats in following two experiments: A Experimental rats underwent the protocol of NHBD lung harvesting: 1 hour of warm ischemia after pentobarbital euthanasia followed with 90 min of cold ischemia (12°C). Under these conditions we compared room-air ventilated rats with non-ventilated during warm ischemia and we were interested in possible protective effect of Tempol (100mg/kg) added pre-arrestly. In controls, lungs were harvested immediately after euthanasia. B We used the same protocol as in A and observed the effect of Tempol added into perfusate at the beginning of reperfusion of NHBD lungs. Ventilation during warm ischemia deteriorates lung functions by the effect of reactive oxygen species. This mechanism was in part A inhibited by pre-arrest administration of Tempol, which prevented development of lung edema and improved oxygen transport ability. In part B Tempol added into the perfusate deteriorated lung functions by causing pulmonary edema. This could be caused by Tempol-mediated inhibition of hypoxic pulmonary vasoconstriction Supported by GAUK 45/2005/C

Effective 6-Hour Preservation in Non-heart-beating Donor Canine Lungs with Topical Cooling: Assessment from Histopathological Aspects

This study assesses the possibility of preserving and transplanting non-heart-beating donor (NHBD) lungs under topical cooling for 6 h. The donor dogs were killed and heparinized after cardiac arrest. After 10 min of cardiac massage, the bilateral lungs were deflated. In group 1 (n = 6), the recipient dogs were transplanted and the lungs preserved at 4 degrees C for 6 h. In group 2 (n = 2), the recipients received lungs preserved at room temperature for 4 h. In both groups the right main bronchus, pulmonary artery, and pulmonary vein were clamped and ventilated to examine the lung function. The mean total ischemic time before reperfusion was 7 h 48 min (group 1) and 5 h 55 min (group 2). All dogs in group 1 survived with excellent hemodynamics and gas exchange function. Both dogs in group 2 revealed congestion immediately after reperfusion, and consequently died. We concluded that it is possible to use NHBD lungs for clinical lung transplantation if topical cooling can be initiated soon after irreversible cardiac arrest. Topical cooling of NHBD lungs allows at least 6 h for preparation before transplantation.

Donor pretreatment using the aerosolized prostacyclin analogue iloprost optimizes post-ischemic function of non-heart beating donor lungs

Background Ischemia-reperfusion injury accounts for one-third of early deaths after lung transplantation. To expand the limited donor pool, lung retrieval from non-heart-beating donors (NHBD) has been introduced recently. However, because of potentially deleterious effects of warm ischemia on microvascular integrity, use of NHBD lungs is limited by short tolerable time periods before preservation. After intravenous prostanoids are routinely used to ameliorate reperfusion injury, the latest evidence suggests similar efficacy of inhaled prostacyclin. Therefore, the impact of donor pretreatment with the prostacyclin analogue iloprost on postischemic NHBD lung function and preservation quality was evaluated. Methods Asystolic pigs (5 per group) were ventilated for 180 minutes of warm ischemia (Group 2). In Group 3, 100 μg iloprost was aerosolized during the final 30 minutes of ventilation with a novel mobile ultrasonic nebulizer. Lungs were then retrogradely preserved with Perfadex and stored for 3 hours. After left lung transplantation and contralateral lung exclusion, hemodynamics, rO 2/F iO 2, and dynamic compliance were monitored for 6 hours and compared with sham-operated controls (Group 1). Pulmonary edema was determined both stereologically and by wet-to-dry weight ratio (W/D). Statistics comprised analysis of variance with repeated measures and Mann-Whitney test. Results Flush preservation pressures, dynamic compliance, inspiratory pressures, and W/D were significantly superior in iloprost-treated lungs, and oxygenation and pulmonary hemodynamics were comparable between groups. Stereology revealed a trend toward lower intraalveolar edema formation in iloprost-treated lungs compared with untreated grafts. Conclusions Alveolar deposition of Iloprost in NHBD lungs before preservation ameliorates postischemic edema and significantly improves lung compliance. This easily applicable innovative approach, which uses a mobile ultrasonic nebulizer, offers an important strategy for improvement of pulmonary preservation quality and might expand the pool of donor lungs.