Ex Vivo Lung Perfusion Increases the Pool of Lung Grafts: Analysis of Its Potential and Real Impact on a Lung Transplant Program

Background

Among the strategies to increase the number of lung transplants, ex vivo lung perfusion (EVLP) represents a novel technique to expand the donor pool.

Methods

Data from donors referred to our center were retrospectively analyzed to identify grafts that could potentially be potentially reconditioned by EVLP and for comparison with those obtained by clinical application of EVLP program in our center.

Results

Among 75 rejected lungs, 23 organs have been identified as potentially treatable with EVLP with a hypothetic increase of lung transplant activity of 53%. After the introduction of the EVLP program in our center, lung transplantation with reconditioned grafts was performed in 7 (23%) patients with a 30% increase in transplant procedures.

Conclusion

Although less than expected, EVLP increased the number of lungs suitable for transplantation.     

Do we need to cool the lung graft after ex vivo lung perfusion? A preliminary study

Background

After normothermic ex vivo lung perfusion (EVLP), pulmonary grafts are usually flush-cooled and stored on ice until implantation although evidence for this practice lacks. We compared outcomes between 2 post-EVLP preservation strategies in a porcine left single-lung transplantation model.

Material and methods

After cold flush and 2-h EVLP, donor lungs were prepared and split. In [C], (n = 5) lungs cooled on device to 15°C were preserved in ice-water; in [W] (n = 5), lungs were disconnected from EVLP at 37°C and kept at room temperature. The left lung was transplanted in a recipient animal. Posttransplant, 6 h-monitoring included hourly assessment of pulmonary vascular resistance, pulmonary artery pressure, plateau airway pressure, compliance, and oxygenation before and after exclusion of the right lung. Lung biopsies and bronchoscopy with bronchoalveolar lavage (BAL) were performed at retrieval, at the end of EVLP (R lung), and 1 and 6 h after reperfusion (L lung).

Results

Lungs in [W] showed the highest compliance (P < 0.05) and the lowest plateau airway pressure (not statistically significant) throughout the whole reperfusion period. Oxygenation and pulmonary artery pressure were similar between groups. Pulmonary vascular resistance was stable in [C], but rose after reperfusion in [W]. Histologic signs of lung injury and BAL neutrophilia were more pronounced in [C] at 1 h (not statistically significant and P < 0.05, respectively). BAL cytokine levels and lung tissue expression of intercellular adhesion molecule 1 did not differ between groups.

Conclusions

Normothermic preparation after EVLP results in similar graft performances compared with lung cooling after EVLP.     

Transplantation of initially rejected donor lungs using ex vivo lung perfusion: A 5-year experience

Background

Ex vivo lung perfusion (EVLP) is a method for the evaluation and reconditioning of high-risk donor lungs to increase the pool of potential donor lungs.

Methods

We reviewed all consecutive patients who received lung transplants from May 2012 to May 2017 with follow-up until July 2021. EVLP was used in lungs initially rejected due to inadequate oxygenation but without other contraindications. Lungs with improved oxygenation levels above the threshold were transplanted. The primary endpoint was the time to graft failure, which was defined as the time from surgery to death or re-transplantation, whichever occurred first. The secondary outcome was freedom from chronic lung allograft dysfunction.

Results

A total of 157 patients underwent transplantation during the study period. Thirty-nine patients received EVLP-treated donor lungs. Restricted mean graft survival time up to 7 years is 5.14 years for non-EVLP and 4.19 for EVLP, the difference being −0.95 (confidence interval [CI]—1.93 to 0.04, p = .059). The hazard ratio is 1.66 (CI 1.00–2.75, p = .046). Chronic lung allograft dysfunction was the highest contributor to mortality in both groups. There were significant differences in freedom from chronic lung allograft dysfunction at 12 and 24 months of follow-up (p = .005 and p = .030, respectively). Subgroup analyses revealed that the first patients who received EVLP in 2012–2013 had a substantially worse 5-year graft survival than those who received EVLP more recently in 2016–2017 (14.3% vs. 60.0%). For the latter, the 5-year graft survival was observed to be remarkably close to the non-EVLP group (60.8%).

Conclusion

Long-term survival was significantly lower, and lung function was poorer among recipients in the EVLP group than in the non-EVLP group. However, the outcome of patients who received EVLP-treated lungs was observed to improve steadily after the first 2 years after EVLP was introduced in Denmark.     

Extracorporeal lung perfusion and ventilation to improve donor lung function and increase the number of organs available for transplantation

Introduction

Ex vivo lung perfusion (EVLP) has been validated as a valuable technique to increase the pool of organs available for lung transplantation.

Material and Methods

After a preclinical experience, we obtained permission from the Ethics Committee of our institution to transplant lungs after EVLP reconditioning. ABO compatibility, size match, and donor arterial oxygen pressure (PaO₂)/fraction of inspired oxygen (FiO₂) ≤ 300 mm Hg were considered to be inclusion criteria, whereas the presence of chest trauma and lung contusion, evidence of gastric content aspiration, pneumonia, sepsis, or systemic disease were exclusion criteria. We only considered subjects on an extra corporeal membrane oxygenation (ECMO) bridge to transplantation with rapid functional deterioration. Using Steen solution with packed red blood cells oxygenated with 21% O₂, 5% to 7% CO₂ was delivered, targeted with a blood flow of approximately 40% predicted cardiac output. Once normothermic, the lungs were ventilated with a tidal volume of 7 mL/kg a PEEP of 5 cmH₂O and a respiratory rate of 7 bpm. Lungs were considered to be suitable for transplantation if well oxygenated [P(v-a) O₂ > 350 mm Hg on FiO₂ 100%], in the absence of deterioration of pulmonary vascular resistance and lung mechanics over the perfusion time.

Results

From March to September 2011, six lung transplantations were performed, including two with EVLP. The functional outcomes were similar between groups: at T72 posttransplantation, the median PaO₂/FiO₂ were 306 mm Hg (range, 282 to 331 mm Hg) and 323 mm Hg (range, 270 to 396 mm Hg) (P = 1, EVLP versus conventional). Intensive care unit ICU and hospital length of stay were similar (P = .533 and P = .663, respectively) with no mortality at 60 days in both groups. EVLP donors were older (49 ± 6 y versus 21 ± 7 y, P < .05), less well oxygenated (184 ± 6 mm Hg versus 570 ± 30, P < .05), displaying higher Oto scores (9.5 ± 0.7 versus 1.7 ± 1.5, P < .05).

Conclusions

The first 6 months of the EVLP program allowed us to increase the number of organs available for transplantation with short-term outcomes comparable to conventional transplantations.     

Pioglitazone attenuates lung injury by modulating adipose inflammation

Background

Pioglitazone modulates adipocyte differentiation and enhances adiponectin promoter activity to increase plasma adiponectin levels. We investigated the effects of pioglitazone on cecal ligation and puncture (CLP)-induced visceral-adipose-tissue inflammation and lung injury in mice.

Materials and methods

Eight-wk-old male mice were assigned to three groups: (1) a sham-operated control group, (2) a CLP group, and (3) a pioglitazone-treated CLP group. Pioglitazone (10 mg/kg) was injected intraperitoneally for 7 d. Serum, lung, and visceral adipose tissue were collected 24 h after surgery. Tumor necrosis factor α (TNF-α) levels in peritoneal lavage fluid were measured by an enzyme-linked immunosorbent assay, and TNF-α and interleukin 6 messenger RNA (mRNA) expression levels in visceral adipose tissue were quantified by real-time polymerase chain reaction. Lung tissue specimens were stained with hematoxylin-eosin, and the terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling method was used to evaluate tissue damage.

Results

TNF-α levels in peritoneal lavage fluid were significantly higher in the CLP group than in the sham group. TNF-α levels in the pioglitazone-treated CLP group were significantly lower than those in the CLP group. TNF-α and interleukin 6 mRNA expression levels of visceral adipose tissue were significantly higher in the CLP group than in the sham group. Pioglitazone treatment decreased the mRNA expression levels of these cytokines compared with the respective values in the CLP group. Histopathologic analysis of lung tissue revealed significantly increased numbers of terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling–positive cells in the CLP group compared with the sham group.

Conclusions

Pioglitazone effectively prevents lung injury caused by CLP-induced sepsis by maintaining the anti-inflammatory status of visceral adipose tissue.     

The consumption of glucose during ex vivo lung perfusion correlates with lung edema

Introduction

Ex vivo lung perfusion (EVLP) has been recently proposed to recondition organs before transplantation from donors with marginal or unacceptable features. The aim of our investigation was to explore glucose consumption during EVLP.

Materials and Methods

We investigated 8 domestic pigs (mean weight, 21 ± 0.8 kg). After perfusion with Perfadex, retrieval, and back table surgery, we initiated EVLP. The lungs were perfused with Steen solution with added methylprednisolone, cefazoline, and heparin. The blood flow was gradually increased with a target of 40% of the estimated cardiac output (or less if the pulmonary artery pressure was >15 mm Hg), while keeping the left atrial pressure between 3 and 5 mm Hg. The temperature of the perfusate was increased from 25°C to 37°C. Once the temperature of the lung outflow was >32°C, we began gas flow (4 L/min, 5%-8% CO₂ in air) and mechanical ventilation. EVLP parameters and blood gases were measured throughout the experiment; glucose consumption was calculated as (glucose initial-glucose final)/time. The wet to dry ratio was also calculated as an index of lung edema.

Results

When stratified by median glucose consumption (0.237 mg/min), high glucose consumers (0.588 ± 0.17) were characterized by worse lung function, as assessed by oxygenation (partial pressure of oxygen/inspiratory fraction of oxygen [PaO₂/FiO₂] 326 ± 63 mm Hg vs 218 ± 84; P = .083 low vs high, respectively), and lung edema (wet/dry ratio 6.5 ± 0.7 vs 8.6 ± 0.9; P = .012). Glucose consumption correlated with wet to dry ratio (R² = 0.663; P = .014).

Conclusions

We found that the worse the lung function, the greater the consumption of glucose during EVLP. This observation suggests the need to explore lung metabolism during EVLP to possibly obtain metrics for evaluation.     

Feasibility of Lung Transplantation From Donation After Circulatory Death Donors Following Portable Ex Vivo Lung Perfusion: A Pilot Study

Background

Donation after circulatory death (DCD) has the potential to significantly alleviate the shortage of transplantable lungs. We report our initial experience with the use of portable ex vivo lung perfusion (EVLP) with the Organ Care System Lung device for evaluation of DCD lungs.

Methylene blue attenuates ischemia–reperfusion injury in lung transplantation

Background

Ischemia–reperfusion injury (IRI) is one of the principal obstacles for the lung transplantation (LTx) success. Several strategies have been adopted to minimize the effects of IRI in lungs, including ex vivo conditioning of the grafts and the use of antioxidant drugs, such as methylene blue (MB). We hypothesized that MB could minimize the effects of IRI in a LTx rodent model.

Methods

Forty rats were divided into four groups (n = 10) according to treatment (saline solution or MB) and graft cold ischemic time (3 or 6 h). All animals underwent unilateral LTx. Recipients received 2 mL of saline or MB intraperitoneally before transplantation. After 2 h of reperfusion, arterial blood and exhaled nitric oxide samples were collected and bronchoalveolar lavage performed. Then animals were euthanized, and histopathology analysis as well as cell counts and cytokine levels measurements in bronchoalveolar lavage fluid were performed.

Results

There was a significant decrease in exhaled nitric oxide, neutrophils, interleukin-6, and tumor necrosis factor-α in MB-treated animals. PaO₂ and uric acid levels were higher in MB group.

Conclusions

MB was able in attenuating IRI in this LTx model.     

Treatment with 3‐aminobenzamide during ex vivo lung perfusion of damaged rat lungs reduces graft injury and dysfunction after transplantation

Ex vivo lung perfusion (EVLP) with pharmacological reconditioning may increase donor lung utilization for transplantation (LTx). 3‐Aminobenzamide (3‐AB), an inhibitor of poly(ADP‐ribose) polymerase (PARP), reduces ex vivo lung injury in rat lungs damaged by warm ischemia (WI). Here we determined the effects of 3‐AB reconditioning on graft outcome after LTx. Three groups of donor lungs were studied: Control (Ctrl): 1 hour WI + 3 hours cold ischemia (CI) + LTx; EVLP: 1 hour WI + 3 hours EVLP + LTx; EVLP + 3‐AB: 1 hour WI + 3 hours EVLP + 3‐AB (1 mg^.mL^?1) + LTx. Two hours after LTx, we determined lung graft compliance, edema, histology, neutrophil counts in bronchoalveolar lavage (BAL), mRNA levels of adhesion molecules within the graft, as well as concentrations of interleukin‐6 and 10 (IL‐6, IL‐10) in BAL and plasma. 3‐AB reconditioning during EVLP improved compliance and reduced lung edema, neutrophil infiltration, and the expression of adhesion molecules within the transplanted lungs. 3‐AB also attenuated the IL‐6/IL‐10 ratio in BAL and plasma, supporting an improved balance between pro‐ and anti‐inflammatory mediators. Thus, 3‐AB reconditioning during EVLP of rat lung grafts damaged by WI markedly reduces inflammation, edema, and physiological deterioration after LTx, supporting the use of PARP inhibitors for the rehabilitation of damaged lungs during EVLP.     

Pretreatment with sildenafil alleviates early lung ischemia-reperfusion injury in a rat model

Background

Lung ischemia-reperfusion (I/R) injury plays an important role in lung transplantation. Less well known is the role of sildenafil in lung I/R injury; therefore, we attempted to determine whether sildenafil could alleviate lung apoptosis and tissue injury in a rat model.

Methods

Forty male Sprague-Dawley rats were randomized into four groups: saline + sham, saline + I/R, sildenafil + sham, and sildenafil + I/R groups. Three hours before the operation, each rat received normal saline or sildenafil (10 mg/kg) by lavage. The animals designed to I/R injury were subjected to 2 h of ischemia induced by occlusion of left pulmonary artery, veins, and bronchus, followed by reperfusion for 2 h. The lung tissue was harvested for the analysis of the expression of Bax, Bcl-2, p53, caspase 3, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and wet/dry (W/D) weight ratio.

Results

Compared with the saline + sham group, the saline + I/R group had significant increases in Bax, p53, Bax/Bcl-2 ratio, caspase 3, IL-6, TNF-α, and W/D weight ratio but a decrease in Bcl-2 (P < 0.05). Compared with the saline + I/R group, sildenafil + I/R group had significant decreases in Bax, p53, Bax/Bcl-2 ratio, caspase 3, IL-6, TNF-α level, and W/D weight ratio but an increase in Bcl-2 expression (P < 0.05). Compared with the sildenafil + sham group, there were significant increases in p53 and TNF-α expression in the sildenafil + I/R group (P < 0.05).

Conclusions

Pretreatment with sildenafil alleviates lung apoptosis and tissue injury in a rat model.     

Innovative,simplified orthotopic lung transplantation in rats

Background

Various techniques of orthotopic single lung transplantation in rats have been reported; however, their widespread use has been limited owing to the complexity of the procedure. We report a novel microsurgical lung transplantation model in rats with a high survival rate that can be performed by one surgeon alone.

Methods

A total of 90 left lung allografts were transplanted from Fischer to Wistar Kyoto rats. We developed a triple axis precision system to place and stabilize the vascular clips intrathoracically to clamp the bronchovascular structures, thereby avoiding interference with the heart and contralateral lung movement. A single-suture bronchial anastomosis technique and proximal cuffing approach for vascular anastomosis was used, rendering surgical assistance unnecessary.

Results

In our recent series, both short-term (12 h) and long-term (21 d) survival was 100%. The lungs showed excellent perfusion and ventilation immediately on transplantation. Blood gas samples drawn from the left pulmonary vein and the histologic sections revealed excellent graft function. The donor operation lasted 20 ± 2 min, donor left lung dissection required 20 ± 2 min, and implantation required 90 ± 5 min.

Conclusions

The present innovative method of left orthotopic single lung transplantation can be performed by one experienced surgeon alone, with excellent results and a high degree of reproducibility.     

Mesenchymal stem cells attenuate ischemia–reperfusion injury after prolonged cold ischemia in a mouse model of lung transplantation: a preliminary study

Purpose

Mesenchymal stem cells (MSCs) suppress inflammation and immune responses. We conducted this study to find out if MSCs attenuate ischemia–reperfusion injury in a mouse model of lung transplantation.

Methods

C57BL/6J mouse lungs perfused with low-potassium dextran glucose solution were preserved at 4 °C for 18 h. Human MSCs were slowly injected into the left pulmonary artery of the lung grafts, and orthotopic left lung transplantation was then performed. The lung isografts were reperfused for 6 h, and bronchoalveolar lavage fluid (BALF) from the left lung graft was collected. We measured the protein concentration, cell count, and proinflammatory cytokine concentrations in the BALF.

Results

The protein concentration and cell count in the BALF were significantly lower in the MSC-administered grafts than in the PBS-administered controls. Concentrations of proinflammatory cytokines, including IL-1β, IL-17A, and TNF-α, in BALF tended to be lower in the MSC-administered grafts than in the controls, but the difference was not significant.

Conclusion

The pre-transplant administration of MSCs via the pulmonary artery of the lung graft attenuated ischemia–reperfusion injury after prolonged cold ischemia in this mouse model of lung transplantation.

     

Comparison of extracellular-type-Kyoto solution and Perfadex as a preservation solution in a pig ex vivo lung perfusion model: impact of potassium level

Background

The ex vivo lung perfusion (EVLP) system has been used successfully to assess donor lungs. Perfadex (PX) is usually the flush and preservation solution in EVLP systems. We have used the extracellular-type-Kyoto (ET-K) solution containing 44 mEq/L potassium for clinical lung transplantation, investigating whether it rather than PX affects the EVLP system.

Methods

We used domestic slaughterhouse pigs to analyze the EVLP system. After 20-minute warm ischemia and 6-hour cold ischemia, EVLP was performed for 2 hours. Pig heart-lung blocks were divided into the PX (n = 5) and ET-K (n = 5) groups depending on the flush/cold preservation solution. At the beginning, we discarded the first 100 mL of effluent in the PX group and the first 200 mL in the ET-K group. We measured pulmonary physiological data and potassium levels.

Results

In both groups, perfusion for 2 hours showed no differences between the 2 groups with respect to the final flow, pulmonary arterial pressure, pulmonary vascular resistance, PaO₂/FiO₂, and shunt fraction. The potassium level in the perfusate was 4.4 mEq/L for the PX and 5.4 mEq/L for the ET-K group.

Conclusion

The pig EVLP system was not affected when ET-K was used instead of PX as the flush/preservation solution. The initial 200 mL of effluent should be discarded when using the ET-K to ensure that the potassium level does not increase.     

Pepsin concentrations are elevated in the bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis after lung transplantation

Background

Aspiration of gastroesophageal refluxate has been implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and the progression of bronchiolitis obliterans syndrome after lung transplantation. The goals of the present study were to identify lung transplant patients at the greatest risk of aspiration and to investigate the causative factors.

Materials and methods

From September 2009 to November 2011, 252 bronchoalveolar lavage fluid (BALF) samples were collected from 100 lung transplant patients. The BALF pepsin concentrations and the results of transbronchial biopsy, esophageal function testing, barium swallow, and gastric emptying scan were compared among those with the most common end-stage lung diseases requiring lung transplantation: IPF, chronic obstructive pulmonary disease, cystic fibrosis, and α₁-antitrypsin deficiency.

Results

Patients with IPF had higher BALF pepsin concentrations and a greater frequency of acute rejection than those with α₁-antitrypsin deficiency, cystic fibrosis, or chronic obstructive pulmonary disease (P = 0.037). Moreover, the BALF pepsin concentrations correlated negatively with a lower esophageal sphincter pressure and distal esophageal amplitude; negatively with distal esophageal amplitude and positively with total esophageal acid time, longest reflux episode, and DeMeester score in those with chronic obstructive pulmonary disease; and negatively with the upright acid clearance time in those with IPF.

Conclusions

Our results suggest that patients with IPF after lung transplantation are at increased risk of aspiration and a greater frequency of acute rejection episodes, and that the risk factors for aspiration might be different among those with the most common end-stage lung diseases who have undergone lung transplantation. These results support the role of evaluating the BALF for markers of aspiration in assessing lung transplant patients as candidates for antireflux surgery.     

Effects of Inhaled Nitric Oxide on Primary Graft Dysfunction in Lung Transplantation

Introduction and Objectives

Inhaled nitric oxide (iNO) is a gaseous drug with known properties of specific pulmonary vasodilation and improved oxygenation. In some clinical trials on lung transplantation (LT) in animals, it has been demonstrated to reduce primary graft dysfunction (PGD) by limiting neutrophil adhesion and the inflammatory cascade. Our objective was to assess whether iNO showed this immunomodulatory effect by determining interleukin (IL)-6, -8, and -10 levels in blood and bronchoalveolar lavage (BAL) in LT patients, and its relationship with PGD incidence.

Materials and Methods

Forty-nine LT patients were recruited and included in the iNO or in the control group. Patients in the first group were given iNO (10 ppm) from the start of LT to 48 hours afterward. BAL and blood samples were taken preimplantation and at 12, 24, and 48 hours after graft reperfusion.

Results

The iNO group displayed a significantly lower incidence (P < .035) of PGD (17.2%) than the control group (45%). Significant differences (P < .05) were also observed in the iNO group with lower levels of IL-6 (in blood at 12 hours), IL-8 (in blood and BAL at 12 and 24 hours), and IL-10 (in blood at 12 and 24 hours and BAL at 24 hours).

Conclusions

PGD is associated with the development of an inflammatory process that is reduced by giving iNO to lung recipients. In our series, the iNO group displayed significantly lower content of IL-6, IL-8, and IL-10 in the majority of samples at 12 and 24 hours compared with the control group.     

Ex Vivo Lung Perfusion: Early Report of Brazilian Experience

Introduction

Only about 15% of the potential candidates for lung donation are considered suitable for transplantation. A new method for ex vivo lung perfusion (EVLP) can be used to evaluate and recondition “marginal,” nonacceptable lungs. We have herein described an initial experience with ex vivo perfusion of 8 donor lungs deemed nonacceptable.

Materials and Methods

After harvesting, the lungs were perfused ex vivo with Steen Solution, an extracellular matrix with high colloid osmotic pressure. A membrane oxygenator connected to the circuit received gas from a mixture of nitrogen and carbon dioxide, maintaining a normal mixed venous blood gas level in the perfusate. The lungs were gradually rewarmed, reperfused, and ventilated for evaluation through analyses of oxygenation capacity, pulmonary vascular resistance (PVR), lung compliance (LC), and biopsy.

Results

The arterial oxygen pressure (with inspired oxygen fraction of 100%) increased from a mean of 206 mm Hg in the organ donor at the referring hospital to a mean of 498 mm Hg during the ex vivo evaluation. After 1 hour of EVLP, PVR varied from 440-1454 dynes/sec/cm⁵; LC was in the range of 26-90 mL/cmH₂O. There was no histological deterioration after 10 hours of cold ischemia and 1 hour of EVLP.

Conclusions

The ex vivo evaluation model can improve oxygenation capacity of “marginal” lungs rejected for transplantation. It has great potential to increase lung donor availability and, possibly, reduce time on the waiting list.     

Association of IL-17F Gene Polymorphisms With Renal Transplantation Outcome

Objective

Although interleukin 17 (IL-17) has some roles in renal transplantation, the influence of IL-17 gene single-nucleotide polymorphisms (SNPs) on renal transplantation has not been studied.

Methods

The associations of 5 IL-17F gene SNPs (–1507G/A, 6329G/A, 7384A/G, 7470G/A, and 7489A/G) with renal transplantation outcome were analyzed. Polymerase chain reaction with sequence-specific primers (for –1507G/A and 6329G/A) and direct sequencing (for 7384A/G, 7470G/A, and 7489A/G) were performed on 282 renal transplantation recipients and 210 healthy controls.

Results

IL-17F SNPs were not associated with acute rejection. Recipients with G allele on 7489A/G showed lower graft survival than recipients without G allele (P = .04). In multivariate analysis, G allele on 7489A/G was an independent risk factor for graft failure (odds ratio = 2.77, P = .03).

Conclusion

IL-17F gene SNP 7489A/G was associated with renal graft failure. Further studies are needed in larger number of patients.     

Establishment of an Ex Vivo Lung Perfusion Model Using Non-Heart-Beating Large Pigs

Background

Functional evaluation of potentially damaged lungs donated after cardiac death is crucial for widespread clinical transplantation. To date, the mean weight of animals used in studies of ex vivo lung perfusion (EVLP) has been 60 kg; however, in the clinical setting, donor weight may be greater.

Objective

To investigate EVLP using lungs from large pigs (mean weight, 115 kg) to simulate human adult lungs donated after cardiac death.

Materials and Methods

Five heart-lung blocks were obtained at 20 minutes after death at the slaughterhouse. The lungs were flushed and preserved on ice for 6 hours before being connected to an ex vivo lung circuit, and were perfused for at least 2 hours.

Results

In all cases, perfusion was sustained for at least 2 hours. Mean (SEM) final flow rate was 4.9 (0.1) L/min, pulmonary artery pressure was 14.8 (1.7) mm Hg, and oxygen tension/fraction of inspired oxygen was 518.0 (18.0) mm Hg. The shunt fraction was 20.5% (4.0%). Histologic analysis demonstrated no significant pulmonary edema at the end of perfusion.

Conclusion

We successfully completed EVLP using lungs from large pigs.     

Diverticulitis occurs early after lung transplantation

Background

Lung transplantation recipients are at an increased risk for developing diverticulitis. However, the incidence and natural history of diverticulitis have not been well characterized. Our objective was to identify patient and transplant-related factors that may be associated with an increased risk of developing diverticulitis in this patient population.

Materials and methods

This is a retrospective single institution study. All patients who received a lung transplant between May 2008 and July 2013 were evaluated using an existing lung transplantation database. Patient-related factors, the incidence and timing of diverticulitis, and outcomes of medical and surgical management were measured.

Results

Of the 314 patients who received a lung transplant, 14 patients (4.5%) developed diverticulitis. All episodes (100%) of diverticulitis occurred within the first 2 y after transplantation. Eight patients (57%) required surgery with a mortality rate of 12.5%. Six patients (43%) were managed medically and did not require surgery with a mean follow-up period of 442 d.

Conclusions

Diverticulitis is common after lung transplantation and occurs with a higher incidence compared with the general population. Diverticulitis occurs early in the posttransplant period, and the majority of patients require surgery. Patients who respond promptly to medical treatment may not require elective resection. A greater awareness of the risk of diverticulitis in the early posttransplant period may allow for earlier diagnosis and treatment.