Perfadex for clinical lung procurement: is it an advance?

Single- and Double-Lung Transplantation: Results of an Initial Experience of 39 Cases in Ceará (Northeast Brazil)

INTRODUCTION

The lung transplantation (LTx) program began in Ceará in 2011 and the first LTx was performed on June 11, 2011. The aim of this study was to present the initial results of the 6-year experience of our program.

METHODS

We retrospectively reviewed our experience on LTx from June 2011 to August 2017. Data on recipients and transoperative and postoperative outcomes were recorded in a database.

RESULTS

Twenty-two (56.4%) were single LTx, 15 (38.5%) were double, and 2 (5.1%) bilateral lobar. The mean age was 47.5 ± 15 years, and 26 (66.7%) were men. Twenty-eight (71.8%) had pulmonary fibrosis; 5 (12.8%) had pulmonary emphysema, 3 (7.7%) had bronchiectasis; 2 (5.1%) had pulmonary hypertension, and 1 (2.6%) had lymphangioleiomyomatosis. Complications occurred in 82% (32/39) and in-hospital mortality was 30.8% (single LTx = 27.8% and double LTx = 33.3%). The main complications were infection in 17 (43.5%) cases and primary graft dysfunction in 7 (17.9%). There was a significant improvement in pulmonary function in the first year of follow-up (forced expiratory volume pre-LTx = 37% ± 16% and 12 months post-LTx = 72% ± 22%, P = .001); and overall survival at 36 months was 59.0%, with no difference between single- and double-lung transplants.

CONCLUSIONS

Idiopathic pulmonary fibrosis was the most common underlying disease and single LTx was the most commonly performed operation. There was a high incidence of postoperative complications and in-hospital mortality, but the 36-month follow-up showed a marked improvement in lung function and a global survival similar to the literature.

Prolonged Mouse Cardiac Graft Cold Storage via Attenuating Ischemia-Reperfusion Injury Using a New Antioxidant-Based Preservation Solution

BACKGROUND

One of the major events in ischemia-reperfusion (I/R)-induced heart injury in cardiac transplantation is the generation of reactive oxygen species. We hypothesized that a novel preservation solution called SBI-SEIIKU II (SS-II) contains 3 antioxidant reagents: L-cysteine, glycine, ascorbic acid/ascorbic acid-2-phosphate magnesium, which can block the generation of reactive oxygen species to result in a prolongation of the cold storage time via attenuating I/R injury.

METHODS

C57BL/6CrSlc(B6) mice underwent syngeneic mice heterotopic heart transplantation, and the animals were derived into 3 groups: recipients with nonpreserved grafts (control group), recipients with grafts preserved in histidine-tryptophan-ketoglutarate (HTK) for 24 and 48 hours (HTK group), and recipients with grafts preserved in SS-II for 24 and 48 hours (SS-II group).

RESULTS

After 48 hours of preservation, there were no grafts that survived in the HTK group; however, the SS-II group had a high survival rate. After 24 hours of preservation, SS-II decreased the oxidative damage, myocardial apoptosis, and the infiltration of macrophages and neutrophils in the cardiac grafts in the early phase and suppressed the development of myocardial fibrosis in long-term grafts compared with HTK.

CONCLUSIONS

The SS-II prolongs the acceptable cold storage time and protects the myocardium from I/R injury via inhibiting oxidative stress-associated damage. We believe that this novel preservation solution may be simple and safe for use in the clinical transplantation field.

Preservation solutions for cardiac and pulmonary donor grafts: a review of the current literature

Hypothermic preservation of donor grafts is imperative to ameliorate ischemia related cellular damage prior to organ transplantation. Numerous solutions are in existence with widespread variability among transplant centers as to a consensus regarding the optimal preservation solution. Here, we present a concise review of pertinent preservation studies involving cardiac and pulmonary allografts in an attempt to minimize the variability among institutions and potentially improve graft and patient survival. A biochemical comparison of common preservation solutions was undertaken with an emphasis on Euro Collins (EC), University of Wisconsin (UW), histidine-tryptophan-ketoglutarate (HTK), Celsior (CEL), Perfadex (PER), Papworth, and Plegisol. An appraisal of the literature ensued containing the aforementioned preservation solutions in the setting of cardiac and pulmonary transplantation. Available evidence supports UW solution as the preservation solution of choice for cardiac transplants with encouraging outcomes relative to notable contenders such as CEL. Despite its success in the setting of cardiac transplantation, its use in pulmonary transplantation remains suboptimal and improved outcomes may be seen with PER. Together, we suggest, based on the literature that the use of UW solution and PER for cardiac and pulmonary transplants, respectively may improve transplant outcomes such as graft and patient survival.

Dynamic instability of central airways and peripheral airspace in rat lungs perfused with cold preservation solutions

BACKGROUND/AIMS

For lung preservation, one of two types of solutions is commonly employed: Euro-Collins (EC) or low potassium dextran glucose (LPDG). These two solutions have been compared regarding biological, morphometrical and physiological outcomes in many experiments. However, the dynamic mechanics of perfused lung are not well understood because the dynamic characteristics cannot be assessed under static conditions; hence, the primary goal of the present study was to assess this in perfused rat lungs during the preservation period, comparing EC with LPDG at 0 or 9 h at 4°C.

METHODS

Lung impedance was measured using a forced oscillation technique. Lung resistance and elastance values were obtained by the fast Fourier transform algorithm. The instability of central airways and heterogeneity of ventilation were estimated.

RESULTS

In the EC group, airway resistance and instability were high after perfusion, and the lung elastance was high and more heterogeneous after cold storage. In contrast, those parameters were stable in the LPDG group during cold storage.

CONCLUSION

Such dynamic stability might facilitate the handling of lung grafts and eliminate injurious cyclic ventilation stress after reperfusion. Thus, we conclude that the impedance frequency characteristic represents a novel informative parameter for investigating lung preservation techniques.

Low potassium dextran is superior to University of Wisconsin solution in high-risk lung transplant recipients

BACKGROUND

The ideal solution for recovery of donor lungs remains unknown. Low potassium dextran (LPD) solution is most common, but University of Wisconsin (UW) solution is also used. The United Network for Organ Sharing (UNOS) database allows assessment of preservation solutions in a large cohort of lung transplant (LTx) patients.

METHODS

We retrospectively reviewed the UNOS data set for adult primary LTx patients (2005-2008) whose donor lungs were recovered with UW or LPD solution. Patients were stratified by UW vs LPD, and secondarily grouped by quartiles of the lung allocation score (LAS) to examine high-risk recipients. Kaplan-Meier (KM) short-term mortality (30 days, 90 days, 1 year) and rejection in the first year were examined for intervals with adequate follow-up. Cox proportional hazard regression using 11 variables examined all cause 1-year mortality.

RESULTS

Of 4,455 patients, 4,161 (93.4%) received LPD lungs and 294 (6.6%) received UW lungs, and 1,105 patients (24.8%) died during the study. There was no mortality difference based on flush solution with all patients examined together. However, patients in the upper 2 LAS quartiles (Q3: 37.8-45.4, Q4: > 45.4) receiving LPD lungs had greater 1-year survival of 81.5% vs 73.5% (p = 0.02). On multivariable analysis, flush with UW solution resulted in an increased risk of 1-year mortality (hazard ratio, 1.77. 95% confidence interval, 1.21-2.58; p = 0.003) vs LPD. Preservation solution did not affect rejection rates in the year after LTx. KM modeling demonstrated the effect of flush solution on survival (p = 0.02).

CONCLUSIONS

This study is the largest modern cohort to evaluate the effect of donor lung flush solutions on survival in adult LTx. UW solution increases the risk of 1-year mortality in high-risk LTx recipients.

Does reperfusion injury still cause significant mortality after lung transplantation?

OBJECTIVES

Severe reperfusion injury after lung transplantation has mortality rates approaching 40%. The purpose of this investigation was to identify whether our improved 1-year survival after lung transplantation is related to a change in reperfusion injury.

METHODS

We reported in March 2000 that early institution of extracorporeal membrane oxygenation can improve lung transplantation survival. The records of consecutive lung transplant recipients from 1990 to March 2000 (early era, n = 136) were compared with those of recipients from March 2000 to August 2006 (current era, n = 155). Reperfusion injury was defined by an oxygenation index of greater than 7 (where oxygenation index = [Percentage inspired oxygen] x [Mean airway pressure]/[Partial pressure of oxygen]). Risk factors for reperfusion injury, treatment of reperfusion injury, and 30-day mortality were compared between eras by using chi(2), Fisher's, or Student's t tests where appropriate.

RESULTS

Although the incidence of reperfusion injury did not change between the eras, 30-day mortality after lung transplantation improved from 11.8% in the early era to 3.9% in the current era (P = .003). In patients without reperfusion injury, mortality was low in both eras. Patients with reperfusion injury had less severe reperfusion injury (P = .01) and less mortality in the current era (11.4% vs 38.2%, P = .01). Primary pulmonary hypertension was more common in the early era (10% [14/136] vs 3.2% [5/155], P = .02). Graft ischemic time increased from 223.3 +/- 78.5 to 286.32 +/- 88.3 minutes in the current era (P = .0001). The mortality of patients with reperfusion injury requiring extracorporeal membrane oxygenation improved in the current era (80.0% [8/10] vs 25.0% [3/12], P = .01).

CONCLUSION

Improved early survival after lung transplantation is due to less severe reperfusion injury, as well as improvements in survival with extracorporeal membrane oxygenation.

Does the method of lung preservation influence outcome after transplantation? An analysis of 681 consecutive procedures

OBJECTIVE

Despite 50 years of lung preservation research, the optimal preservation technique is undefined. Using data from a national cohort, we investigated outcomes with different preservation methods after adult lung transplantation.

METHODS

Early (30-day), late (30-day to 3-year), and overall (3-year) mortalities, adjusted for differences in donor and recipient characteristics, were compared by using Cox regression. Intensive care unit length of stay and the number of rejection episodes were secondary outcomes.

RESULTS

Six hundred eighty-one eligible lung transplantations between July 1995 and June 2003 were preserved with Euro-Collins solution (n = 284), blood albumin (n = 139), core cooling (n = 107), or low potassium dextran solution (n = 151). There was significantly increased use of low potassium dextran solution over time (P < .001). Unadjusted 3-year survival was similar across the groups (P = .72), with the highest 3-year survival in the low potassium dextran group (62%; 95% confidence interval, 51%-72%) and the lowest in the blood albumin group (49%; 95% confidence interval, 39%-58%). Risk-adjusted early (P = .70), late (P = .27), and overall (P = .72) survival was similar across the groups and was not affected by ischemic time. Freedom from death caused by primary graft dysfunction was again highest in the low potassium dextran group (95%; 95% confidence interval, 90%-98%) and lowest in the blood albumin group (91%; 95% confidence interval, 85%-95%). There was no difference in intensive care unit length of stay. An increased incidence of rejection was apparent with increasing ischemic time (P = .067).

CONCLUSION

The methods of lung preservation in current use do not seem to affect early or midterm survival after transplantation, but increasing ischemic time might predispose to increased rejection.

Reducing Ischemia–Reperfusion Injury in Clinical Lung Transplantation

OBJECTIVE

Acute graft dysfunction secondary to ischemia-reperfusion injury (IRI) continues to be the most common cause of early mortality after lung transplantation. The perioperative management with aprotinin could decrease the incidence of severe IRI.

METHODS

A retrospective analysis was conducted of the data from 180 patients who underwent either single lung (56%) or bilateral sequential lung transplantation for similar end-stage lung disease between 1997 and 2005. The most recent 68 patients were managed perioperatively with the high-dose aprotinin infusion regimen (aprotinin group). The ISHLT grade III injury score was used for the diagnosis of severe IRI, which is based on a Pao(2)-FIo(2) ratio of less than 200 mmHg.

RESULTS

Grade III injury was observed in 18% of the patients who were not managed with aprotinin (control group, 152 grafts, 64% single transplants, 68% male, 54 +/- 8 years of age). Early ECMO support was required in 25% of these patients. The associated mortality rate was 40%. Despite significantly longer cold ischemic times (290 +/- 14 minutes vs 231 +/- 14 minutes), older donors (42 +/- 12 years of age), and more frequently observed severely elevated systolic PAP of greater than 60 mmHg (60% vs 48%) as well as more frequently required extracorporeal circulatory support (24%* vs 12%) in the aprotinin group, the incidence of severe IRI (8%) and associated mortality (9%) was markedly reduced.

CONCLUSIONS

The use of aprotinin in LTX surgery, which had strong beneficial effects on patient outcomes, significantly decreased the incidence of severe posttransplant IRI.

Effect of Preservation Solution on Graft Viability in Single-Lung Transplantation From Heart-Beating Donors in Pigs

BACKGROUND

Low-potassium-dextran preservation solution Perfadex (PER) may provide better outcome of transplanted lungs than high-potassium Euro-Collins (EC) solution. However, there are no comparative studies of the recipient inflammatory response to the graft.

PURPOSE

The purpose of this study was to compare EC versus PER as preservation solutions with respect to the functional performance and inflammatory response in single-lung transplantation from heart-beating donors in pigs.

MATERIALS AND METHODS

The donor left lung flushed with the corresponding cold preservation solution was stored at 3 degrees C for 3 hours. We assessed hemodynamic values and pulmonary function in the recipient over a 2-hour reperfusion period calculated as percent of basal values, and expressed as mean of the reperfusion period. Interleukin-8 (IL-8) concentration in the donor was estimated in bronchoalveolar lavage fluid 2 hours after recipient reperfusion. Biopsies of the donor right lung and the transplanted lung were obtained to measure myeloperoxidase (MPO) activity. IL-8 and MPO values were expressed as percent of the donor value. We evaluated the wet/dry pulmonary weight ratio (W/D), polymorphonuclear neutrophil count (PMN), and a score of histological damage in the transplanted graft.

RESULTS

Pulmonary function evaluated by % static: 66.6 +/- 6.8 (EC), 82.3 +/- 10.2 (PER), and dynamic: 74.0 +/- 7.3 (EC), 89.3 +/- 7.7 (PER) compliances, as well as % IL-8: 562.5 +/- 168.6 (EC), 232.3 +/- 148.7 (PER), % MPO: 485.9 +/- 194.9 (EC), 140.8 +/- 21.1 (PER), W/D: 9.9 +/- 3.1 (EC), 6.8 +/- 1.4 (PER), PMN 13.5 +/- 6.8 (EC), 5.5 +/- 3.3 (PER) and the histological damage score: 3.0 +/- 1.5 (EC), 0.7 +/- 0.4 (PER) showed significant differences between the EC and the PER (P < .01).

CONCLUSIONS

PER affords good lung preservation with early graft function and modest evidences of inflammation, lung injury, and edema compared with the EC perfused lung.

Estudio comparativo de dos soluciones de preservación en la función inicial del trasplante bipulmonar en humanos

OBJECTIVE

Compare the influence of two preservation liquids, Euro-Collins (EC) and Perfadex (P) in the pulmonary graft function in the initial phase of lung transplant in humans.

DESIGN

Retrospective study.

SCOPE

Lung transplant unit of the ICU of a university hospital.

PATIENTS

A total of 79 patients were subjected to a transplant of both lungs. The pulmonary grafts were preserved with EC in 23 cases and with P in 56 cases.

VARIABLES OF INTEREST

Pulmonary function was assessed on admission in the intensive care unit (ICU) with the PaO2/FiO2 ratio. Mortality, graft dysfunction stay in ICU and time of mechanical ventilation were also assessed at 30 days.

RESULTS

The PaO2/FiO2 ratio was significantly greater in the P group than in the EC both on admission (p<0.006) and at 12 hours (p=0.032) in the ICU. Graft dysfunction incidence was less in group P than in EC (p<0.045). There were no differences in regards to mortality at 30 days, stay in ICU and time of mechanical ventilation between both groups.

CONCLUSION

Preservation of the pulmonary graft with P as preservation liquid compared with EC is associated with better graft function in the initial phases of transplant of both lungs and with a decrease in the incidence of graft dysfunction.

Early outcomes comparing Perfadex, Euro-Collins, and Papworth solutions in lung transplantation

BACKGROUND

Despite improved surgical techniques and medical management, primary graft dysfunction (PGD) remains a major cause of early morbidity and mortality after lung transplantation. Different types of lung preservation solutions have been developed and applied to clinical use; however, the relative clinical efficacy of these solutions to prevent PGD remains controversial. This study aimed to investigate the effect of the three solutions most commonly used (Perfadex [Vitrolife, Göteborg, Sweden], Papworth, and Euro-Collins [Baxter Healthcare, Old Toongabbie NSW, Australia]) on posttransplant outcomes.

METHODS

Early outcomes from 157 consecutive lung transplants (113 bilateral and 44 single) performed at The Alfred Hospital were compared across three preservation solutions.

RESULTS

Posttransplant oxygenation (p = 0.57), pulmonary vascular resistance (p = 0.34), intubation hours (p = 0.66), intensive care unit days (p = 0.34), severe PGD (grade 3) (p = 0.70), 30-day mortality (p = 0.87), and 3-month % predicted forced expiratory volume in 1 second (p = 0.58) were not statistically different; however, Perfadex trended toward superiority among the three solutions. After adjustment of donor, recipient, and operative factors in multivariate analysis, Perfadex was significantly associated with the prevention of moderate to severe PGD (grade 2 to 3) at 48 hours posttransplant (odds ratio = 0.26 [0.10 to 0.72], p < 0.01) compared with Papworth (odds ratio = 0.75 [0.32 to 1.75], p = 0.51) and Euro-Collins (reference) solutions.

CONCLUSIONS

Although any advantageous effects of Perfadex on early posttransplant outcomes were generally subtle and statistically nonsignificant, Perfadex prevented moderate to severe PGD. Switching preservation solution from Euro-Collins (or Papworth) to Perfadex would appear to usefully contribute to a strategy to reduce PGD in lung transplantation.

Does Perfadex Affect Outcomes In Clinical Lung Transplantation?

BACKGROUND

The use of a low-potassium-based preservation solution improves gas exchange in experimental models of lung transplantation. However, its efficacy in reducing the incidence of primary graft dysfunction (PGD) and improving patient outcomes in the clinical setting is controversial.

METHODS

In this study we measured: oxygenation index (OI); International Society of Heart and Lung Transplantation (ISHLT) PGD grades; extubation times; intensive care unit (ICU) and hospital length of stay; 30-day, 90-day and 1-year survival rates; and bronchiolitis obliterans syndrome (BOS)-free survival. We compared 115 consecutive (2001 to 2004) lung recipients who received allografts preserved with Perfadex, a low-potassium dextran (LPD) solution, and compared the results with the previous 116 consecutive (1999 to 2001) lung recipients who received allografts preserved with modified Euro-Collins (MEC) solution. Recipients were classified as having severe PGD (ISHLT Grade III) if the lowest arterial oxygenation (P) to fraction of inspired oxygen (F) (P/F ratio) within 48 hours post-transplantation was <200.

RESULTS

Baseline characteristics of the 2 cohorts were similar except for recipient age (LPD 53.5 vs MEC 49.9 years; p = 0.03). There were no differences in donor age, gender, category of transplant, indication for transplant, use of cardiopulmonary bypass or pre-operative pulmonary artery pressures. When gas-exchange parameters were measured upon arrival to the ICU (T0), at 24 hours post-transplant (T24) and at 48 hours post-transplant (T48), the only significant finding was that the incidence of ISHLT Grade III PGD at T24 was lower in the LPD group compared with the MEC group (8% vs 20%, p = 0.03). The incidence of severe PGD at other timepoints was not statistically different (LPD vs MEC: T0, 17% vs 26%; T0 to T48, 25% vs 31%). Both groups had similar extubation rates at 48 hours post-transplant (LPD 64% vs MEC 67%). The 30-day survival (LPD 93% vs MEC 95%), 90-day survival (LPD 89% vs MEC 89%), 1-year patient survival (LPD 80% vs MEC 77%) and 1-year BOS-free survival (LPD 70% vs MEC 74%) were not statistically different.

CONCLUSIONS

Lung preservation with LPD as compared with MEC does not improve early gas exchange or impact 90-day and 1-year mortality. Continued investigation into lung preservation solution composition is necessary to reduce the incidence of PGD.

Lung preservation

Better understanding of the mechanisms of ischemia-reperfusion injury, improvement in the technique of lung preservation, and the recent introduction of a new preservation solution specifically developed for the lungs have helped to reduce the incidence of primary graft dysfunction after lung transplantation. Currently, the limitation in extending the ischemic time is more often related to the increasing use of non-ideal lung donors rather than to poor lung preservation. In this review, we have focused our attention on the experimental and clinical work performed to optimize the methods of lung preservation from the time of retrieval to the period of reperfusion after graft implantation.

Plasmolemmal potassium gradient does not affect lung protection by an ATP-regulated potassium channel opener

BACKGROUND

We have previously shown that metabolic arrest induced with ATP-regulated potassium channel openers (PCOs) can improve lung preservation by adding Aprikalim (a PCO, Rhone-Poulene Roher) to modified Euro-Collins solution for pulmonary artery flush. Because the membrane hyperpolarizing effects of a PCO potentially competes with the depolarizing effects of a hyperkalemic solution, this study evaluated the effects of the potassium gradient on PCO-mediated lung protection.

STUDY DESIGN

Twenty rabbits underwent lung protection in four groups. Group 1 underwent harvest and reperfusion as a "no ischemia" control. Groups 2, 3, and 4 underwent harvest followed by 18 hours of cold ischemic storage before reperfusion. Groups 1 and 4 received Euro Collins as the pulmonary flush at induction of ischemia. Group 2 received Euro Collins plus Aprikalim (100 microM); and group 3 received lactated Ringer's plus Aprikalim. After ischemic storage, the lungs were reperfused with autologous blood for 2 hours. Every 30 minutes, the lungs were given a 10-minute 100% fractional inspired oxygen (F(i)O(2)) challenge to measure maximal gas exchange as an indication of graft function.

RESULTS

Repeated measures ANOVA showed Aprikalim improved graft function after 18 hours of cold ischemia (p < 0.0001). No significant differences were found when Aprikalim was used in either Euro-Collins (group 2) or lactated Ringer's (group 3) solution.

CONCLUSIONS

The ability of the PCO Aprikalim to preserve gas exchange in a model of hypothermic pulmonary ischemia-reperfusion injury was not affected by the plasmolemmal potassium gradient. This is consistent with recent findings in myocardial protection studies that the protective effects of PCOs may be intracellular.

Experimental study of extracorporeal lung resection in dogs: ex situ sleeve resection and autotransplantation of the pulmonary lobe after extended pneumonectomy for central lung cancer

OBJECTIVE

Extracorporeal lung resection as an alternative to pneumonectomy for central lung cancer is a procedure in which the unilateral lung is extirpated, removing the pulmonary lobe with the cancers and replanting the residual pulmonary lobe. The aim of this study was to investigate whether extracorporeal lung resection for lung cancer can be performed safely.

METHODS

Nineteen dogs were divided into the control and extracorporeal lung resection groups. The former (n = 5) underwent lung autotransplantion, and the latter was subdivided into ND1 (n = 7) and ND2 (n = 7) groups on the basis of the manner of lymph node dissection. By comparing the 3 groups, the adverse effects of lymph node dissection were examined.

RESULTS

All dogs in the control group had no complications. Four dogs in the ND1 group survived for 90 to 630 days after the operation. In the ND2 group 5 dogs succumbed within 30 days after the operation, although the other 2 dogs survived for 391 and 573 days, respectively. Bronchopulmonary fistulas were seen in 1 of the ND1 dogs and 3 of the ND2 dogs. Two of the latter were free of thrombus formation in the pulmonary arteries and veins of the autografts. In the ND2 group, compared with the control and ND1 group, the tissue blood flow at the bronchial anastomotic site indicated reduction between the 3rd and 14th postoperative days.

CONCLUSION

The extensive lymph node dissection had severe adverse effects on bronchial anastomotic healing in extracorporeal lung resection. Therefore extracorporeal lung resection can be applied to only a very limited number of patients with N0 or N1 disease.