Lung Donation After Controlled Circulatory Determination of Death: A Review of Current Practices and Outcomes

Postoperative Acute Kidney Injury and Long-Term Outcomes After Lung Transplantation

BACKGROUND

This study sought to characterize perioperative risk factors of acute kidney injury (AKI) and report outcomes associated with its development in the immediate postoperative setting after lung transplantation.

METHODS

Study investigator performed a retrospective analysis of all adult patients undergoing primary lung transplantation at a single institution from January 1, 2011 to December 31, 2021 AKI was defined using Kidney Disease: Improving Global Outcomes (KDIGO) criteria after lung transplantation and was stratified on the basis of whether patients required renal replacement therapy (RRT; AKI-no RRT vs AKI-RRT).

RESULTS

Of the 754 patients included, 369 (48.9%) any AKI developed in the postoperative period (252 AKI-no RRT vs 117 AKI-RRT). Risk factors for postoperative AKI included higher preoperative creatinine levels (odds ratio [OR], 5.15; P < .001), lower preoperative estimated glomerular filtration rate (OR, 0.99; P < 0.018), delayed chest closure (OR, 2.72; P < .001), and higher volumes of postoperative blood products (OR, 1.09; P < .001) in the multivariable analysis. On univariate analysis, both AKI groups were also associated with higher rates of pneumonia (P < .001), reintubation (P < .001), mortality on index admission (P < 0.001), longer ventilator duration (P < .001), longer intensive care unit length of stay (P < .001), and longer hospital length of stay (P < .001), with the highest rates in the AKI-RRT group. In a multivariable survival analysis, postoperative AKI-no RRT (hazard ratio [HR], 1.50; P = .006) and AKI-RRT (HR, 2.70; P < .001) were associated with significantly worse survival independent of severe grade 3 primary graft dysfunction at 72 hours (HR, 1.45; P = .038).

CONCLUSIONS

The development of postoperative AKI was associated with numerous preoperative and intraoperative factors. Postoperative AKI remained significantly associated with poorer posttransplantation survival. Severe cases of AKI necessitating RRT portended the worst survival after lung transplantation.

Donation after circulatory death (DCD)-lung procurement

The number of lungs available for lung transplantation is far lower than the number of patients awaiting them. Consequently, there is a significant attrition rate while awaiting transplantation. Lung procurement rates are lower than those of other solid organs. Lungs are procured from only 15–20% of donors compared with 30% of decreased donors for hearts. The reason for this low retrieval rate is related to a number of factors. Brain death is associated with neurogenic pulmonary edema. Additionally, injury to the lung itself may occur before or after brain death. Aspiration of gastric contents, pneumonia, previous thoracic trauma, ventilator-associated injury, atelectasis, and pulmonary thrombosis/embolism may all contribute to lung injury before consideration for harvest. Donation after circulatory death (DCD) is one category of nontraditional organ donation now being performed in increasing numbers as a way to increase the number of lungs available for transplantation. In some studies, estimates show that utilization of DCD lung procurement could increase the number of lungs available by up to 50%.

Effect on the donor lungs of using abdominal normothermic regional perfusion in controlled donation after circulatory death

OBJECTIVES

Controlled donation after circulatory death (cDCD) donors are becoming a common source of organs for transplantation globally. However, the graft survival rate of cDCD abdominal organs is inferior to that of organs from brain-dead donors. The rapid retrieval (RR) technique is used by most donor organ procurement teams. The abdominal normothermic regional perfusion (A-NRP) technique has been implemented to minimize warm ischaemic damage to the abdominal organs. However, there is limited information on the effect of A-NRP on the quality of the donor lungs. This study aimed to compare lung transplantation outcomes using lungs procured from cDCD donors using the A-NRP and abdominal RR techniques.

METHODS

A single-centre retrospective analysis of consecutive transplant recipients of cDCD lungs from June 2013 to December 2019 was performed. The recipients were divided into 2 cohorts according to the abdominal procurement technique used. The recipient and donor characteristics (age, sex, cause of brain injury, warm ischaemic time, diagnosis, lung allocation score and other factors), incidence of primary graft dysfunction and early survival were monitored.

RESULTS

Twenty-eight consecutive lung transplantation recipients were identified (median age 59 years; 61% male); 14 recipients received lungs using the A-NRP and 14 using abdominal RR for abdominal organ retrieval. There were no significant differences in the baseline characteristics, primary graft dysfunction (P = 0.70), hospital mortality (P = 1.0) and 1-year survival rate (P = 1.0) between the 2 groups.

CONCLUSIONS

No difference was observed in lung transplantation outcomes irrespective of the abdominal organ procurement technique used (A-NRP or abdominal RR).

Utilization of extracorporeal membrane oxygenation in DCD and DBD lung transplants: a 2-year single-center experience

Donation after circulatory death (DCD) has the potential to expand the lung donor pool. We aimed to assess whether DCD affected the need for perioperative extracorporeal membrane oxygenation (ECMO) and perioperative outcomes in lung transplantation (LTx) as compared to donation after brain death (DBD). All consecutive LTxs performed between April 2017 and March 2019 at our tertiary center were analyzed. Donor and recipient preoperative characteristics, utilization of ECMO, and perioperative clinical outcomes were compared between DCD and DBD LTx. Multivariate models (frequentist and Bayes) were fitted to evaluate an independent effect of DCD on the intra- and postoperative need for ECMO. Out of 105 enrolled patients, 25 (23.8%) were DCD LTx. Donors' and preoperative recipients' characteristics were comparable between the groups. Intraoperatively, mechanical circulatory support (MCS) was more common in DCD LTx (56.0% vs. 36.2%), but the adjusted difference was minor (RR = 1.16, 95% CI 0.64-2.12; P = 0.613). MCS duration, and first and second lung ischemia time were longer in the DCD group. Postoperatively, DCD recipients more commonly required ECMO (32.0% vs. 7.5%) and the difference remained considerable after adjustment for the pre- and intraoperative covariates: RR = 4.11 (95% CI 0.95-17.7), P = 0.058, Bayes RR = 4.15 (95% CrI 1.28-13.0). Sensitivity analyses (two DCD-DBD matching procedures) supported a higher risk of postoperative ECMO need in DCD patients. Incidence of delayed chest closure, postoperative chest drainage, and renal replacement therapy was higher in the DCD group. Early postoperative outcomes after DCD LTx appeared generally comparable to those after DBD LTx. DCD was associated with a higher need for postoperative ECMO which could influence clinical outcomes. However, as the DCD group had a significantly higher use of EVLP with more common ECMO preoperatively, this might have contributed to worse outcomes in the DCD group.