The University of Alberta Negative Pressure Ventilation Ex-Vivo Lung Perfusion (NPV-EVLP) Trial

The University of Alberta Negative Pressure Ventilation Ex-Vivo Lung Perfusion (NPV-EVLP) Trial

This project is focused on helping one of the most vulnerable patient populations in medicine, patients with end-stage chronic lung disease. Lung transplantation is the only cure for end-stage lung disease, however, due to the persistent shortage of donor organs, either due to low organ donation rates or unacceptable organs, only a minority of patients receive desperately needed lung transplants. Currently less than 30% of potential donated thoracic organs are being used for transplantation. The major causes for under utilization of donor thoracic organs are injury sustained by the lungs in trauma or emergency resuscitation or lungs that come from donors who are pronounced dead due to cardiac arrest (known as DCD donors). It has been hypothesized that these injuries may be reversible or repairable if there was an opportunity to evaluate and repair these organs outside of the body (ex-vivo), prior to transplantation. In fact, studies have shown that the use of normothermic Ex-Vivo Lung Perfusion (EVLP) has increased the rate of donor organ utilization at centers that have adopted the technology.

Current methodology for all clinically available EVLP devices uses Positive Pressure Ventilation (PPV). Researchers at the University of Alberta (UofA), however, have developed an EVLP device that will apply Negative Pressure Ventilation (NPV) to the lungs, as opposed to PPV, which is the most ideal mimicry of native lung physiology. The objective of this early feasibility safety trial is to show that the UofA developed NPV-EVLP device is acceptable in evaluating and improving the quality of marginal donor lungs compared to currently used EVLP devices, ultimately allowing for these types of donor lungs to be safely transplanted into patients on the lung transplant recipient waitlist.

5.2 PRE-NPV-EVLP Donor Eligibility Criteria

5.2.1 Donor MUST meet ANY ONE of the following Inclusion Criteria to proceed with NPV-EVLP:

1. Best ratio of the PaO2 to FiO2 of < 300mmHg;
2. Pulmonary edema, defined as bilateral interstitial infiltrates without evidence of infection, detected on the last chest radiograph by the lung-transplantation physician assessing the donor;
3. Poor lung deflation or inflation during direct intraoperative visual examination at the donor site;
4. Donor age is ≥ 55 years;
5. Expected cold ischemic time > 6 hours;
6. Blood transfusions ≥ 10 units; or
7. Donation after cardiac death (DCD), as defined by Maastricht category III (donor without a heartbeat and with cardiocirculatory death imminent after withdrawal of treatment) or category IV (cardiocirculatory death in a brain-dead donor).

5.2.2 Donor Exclusion Criteria to NOT proceed with NPV-EVLP:

1. Donor lungs with established pneumonia;
2. Severe mechanical lung injury (i.e., contusions in more than one lobe) or trauma determined by chest x-ray, bronchoscopy, CT scan or visual inspection; or
3. Gross gastric aspiration within the lungs
4. Donor lungs have active infectious disease such as HIV, Hepatitis B, Hepatitis C, West Nile Virus (WNV), HTLV, or Syphillis (if this information not available at start of EVLP, it should be re-assessed prior to transplant).

5.3 POST-NPV-EVLP Donor Eligibility Criteria

5.3.1 Donor Inclusion Criteria to proceed with Transplant:

1. Surgeon must be satisfied with the clinical evaluation and appearance of the lungs; if not, reason for refusal must be documented;
2. Lungs show PaO2/FiO2 ratio ≥ 350mmHg; AND
3. Deterioration of less than 15% from baseline for physiological measurements pulmonary vascular resistance (PVR), dynamic compliance and peak inspiratory pressure.

5.3.2 Donor Exclusion Criteria to proceed with Transplant:

1. Lungs show a PaO2/FiO2 ratio of < 350mmHg;
2. Greater than 15% functional deterioration across the following physiological parameters: PVR, dynamic compliance and peak inspiratory pressure;
3. Donor lungs are positive for infectious disease such as HIV, Hepatitis B, Hepatitis C, West Nile Virus (WNV),HTLV, or Syphillis.

5.4 Recipient Eligibility Criteria

5.4.1 Recipient Inclusion Criteria

1. Patients on our institution's waitlist requiring bilateral transplantation
2. Male or Female 18 years of age or older
3. Written informed consent provided.

5.4.2Recipient Exclusion Criteria

1. Multi-organ recipient or re-transplant
2. HIV, Hepatitis, or other infection that excludes subject from transplant in the study
3. Subject is on hemodialysis or has chronic severe renal dysfunction
4. Concurrent cardiac procedure
5. Recipient is on Nova Lung, ECMO or on mechanical ventilation (CPAP and BiPAP not exclusionary)