Donor lung assessment using selective pulmonary vein gases

OBJECTIVES

Standard donor lung assessment relies on imaging, challenge gases and subjective interpretation of bronchoscopic findings, palpation and visual assessment. Central gases may not accurately represent true quality of the lungs. We report our experience using selective pulmonary vein gases to corroborate the subjective judgement.

METHODS

Starting, January 2012, donor lungs have been assessed by intraoperative bronchoscopy, palpation and visual judgement of lung collapse upon temporary disconnection from ventilator, central gases from the aorta and selective pulmonary vein gases. Partial pressure of oxygen (pO₂) <300 mmHg on FiO₂ of 1.0 was considered low. The results of the chest X-ray and last pO₂ in the intensive care unit were also collected. Post-transplant primary graft dysfunction and survival were monitored.

RESULTS

To date, 259 consecutive brain-dead donors have been assessed and 157 transplants performed. Last pO₂ in the intensive care unit was poorly correlated with intraoperative central pO₂ (Spearman's rank correlation r_s = 0.29). Right inferior pulmonary vein pO₂ was associated (Mann-Whitney, P < 0.001) with findings at bronchoscopy [clean: median pO₂ 443 mmHg (25th-75th percentile range 349-512) and purulent: 264 mmHg (178-408)]; palpation [good: 463 mmHg (401-517) and poor: 264 mmHg (158-434)] and visual assessment of lung collapse [good lung collapse: 429 mmHg (320-501) and poor lung collapse: 205 mmHg (118-348)]. Left inferior pulmonary pO₂ was associated (P < 0.001) with findings at bronchoscopy [clean: 419 mmHg (371-504) and purulent: 254 mmHg (206-367)]; palpation [good: 444 mmHg (400-517) and poor 282 mmHg (211-419)] and visual assessment of lung collapse [good: 420 mmHg (349-496) and poor: 246 mmHg (129-330)]. At 72 h, pulmonary graft dysfunction 2 was in 21/157 (13%) and pulmonary graft dysfunction 3 in 17/157 (11%). Ninety-day and 1-year mortalities were 6/157 (4%) and 13/157 (8%), respectively.

CONCLUSIONS

Selective pulmonary vein gases provide corroborative objective support to the findings at bronchoscopy, palpation and visual assessment. Central gases do not always reflect true function of the lungs, having high false-positive rate towards the individual lower lobe gas exchange. Objective measures of donor lung function may optimize donor surgeon assessment, allowing for low pulmonary graft dysfunction rates and low 90-day and 1-year mortality.

Donors with a prior history of cardiac surgery are a viable source of lung allografts

OBJECTIVES

End-stage lung disease continues to rise despite the lack of suitable lung donors, limiting the numbers of lung transplants performed each year. Expanded donor criteria, use of donation after cardiac death donors and the advent of ex vivo lung perfusion have resulted only in a slight increase in donor lung utilization. Organ donors with prior cardiac surgery (DPCS) present risks and technical challenges; however, they may be a potential source of suitable lung allografts with an experienced procurement surgeon. We present our experience having evaluated potential lung donors with a prior history of cardiac surgery, resulting in successful transplant outcomes.

METHODS

This is a single-institution retrospective review of brain-dead organ donors that were evaluated for lung donation in the period 2012-15. Donor and recipient characteristics were collected. Post-lung transplant survival was recorded.

RESULTS

From 2012 to 2015, 259 donors were evaluated, 12 with a prior history of cardiac surgery of which 4 had coronary artery bypass, 3 had aortic root replacement, 2 had aortic valve replacement, 1 pulmonary embolectomy, 1 two-time reoperative valve replacement and 1 paediatric congenital ventricular septal defect repair. DPCS, 6/12 (50% dry run) provided suitable allografts generating six single-lung transplants (three right and three left, 1 donor provided twin single-lung transplants) and one double-lung transplant. Interval between cardiac surgery and procurement for those rejected was median 5840 (IQR 2350-8640) days and interval for the donors that provided allografts was median 438 (IQR 336-1095) days (Mann-Whitney, P = 0.07). Recipient 1-year survival from DPCS is 100%. Recipient 1-year survival was 92% in allografts explanted from donors with no prior cardiac surgery (2012-13).

CONCLUSION

To date, this is the largest single-centre experience using lung allografts from brain-dead DPCS. Our experience shows despite predicted technical difficulties, with good communication between thoracic and abdominal teams, successful transplant outcomes are possible, when surgeons with experience in reoperative cases are sent for lung procurements.