Chest computed tomography imaging improves potential lung donor assessment

"Horses for courses" computed tomography or predicted total lung capacity for size matching in lung transplantation

Size-matching donors to recipients in lung transplantation continues to be a clinical challenge. Predicted total lung capacity equations, or more simply, donor and recipient heights, while widely used, are imprecise and may not be representative of the pool of donors and recipients. These inherent limitations may result in size discrepancies. The advent of easily accessible software and the widespread availability of computed tomography (CT) imaging in donor assessments have made it possible to directly measure lung volumes in donors and recipients. As a result, there is a growing interest in adopting personalized CT volumetry as an alternative. This article explores both methods and underscores the potential benefits and precision offered by CT.

Imaging of Lung Transplantation

Lung transplantation is the only curative treatment for end-stage lung disease, which is caused by a wide variety of pathologies and encountered in a diverse range of patients. Potential recipients, as well as donors are carefully evaluated by imaging prior to transplant for contraindications to the transplant. After transplantation, recipients are imaged in the immediate, early, intermediate, and late periods for complications that may arise and require intervention. Radiography and computed tomography are the 2 most commonly used imaging modalities used to evaluate the chest after lung transplantation.

Computed tomography-based machine learning for donor lung screening before transplantation

BACKGROUND

Assessment and selection of donor lungs remain largely subjective and experience based. Criteria to accept or decline lungs are poorly standardized and are not compliant with the current donor pool. Using ex vivo computed tomography (CT) images, we investigated the use of a CT-based machine learning algorithm for screening donor lungs before transplantation.

METHODS

Clinical measures and ex situ CT scans were collected from 100 cases as part of a prospective clinical trial. Following procurement, donor lungs were inflated, placed on ice according to routine clinical practice, and imaged using a clinical CT scanner before transplantation while stored in the icebox. We trained and tested a supervised machine learning method called dictionary learning, which uses CT scans and learns specific image patterns and features pertaining to each class for a classification task. The results were evaluated with donor and recipient clinical measures.

RESULTS

Of the 100 lung pairs donated, 70 were considered acceptable for transplantation (based on standard clinical assessment) before CT screening and were consequently implanted. The remaining 30 pairs were screened but not transplanted. Our machine learning algorithm was able to detect pulmonary abnormalities on the CT scans. Among the patients who received donor lungs, our algorithm identified recipients who had extended stays in the intensive care unit and were at 19 times higher risk of developing chronic lung allograft dysfunction within 2 years posttransplant.

CONCLUSIONS

We have created a strategy to ex vivo screen donor lungs using a CT-based machine learning algorithm. As the use of suboptimal donor lungs rises, it is important to have in place objective techniques that will assist physicians in accurately screening donor lungs to identify recipients most at risk of posttransplant complications.

Transplant Outcomes After Exposure of Deceased Kidney Donors to Contrast Medium

BACKGROUND

The administration of contrast medium is associated with acute kidney injury; however, the effect of exposure of a deceased organ donor to contrast medium on kidney transplant outcomes has been poorly studied.

METHODS

A retrospective analysis of all deceased kidney donors between 2011 and 2021 and their corresponding recipients in the Netherlands was conducted. Multivariable analyses were performed to assess the associations between contrast medium exposure and delayed graft function (DGF)/graft survival. Linear mixed models were used to assess the differences in mean estimated glomerular filtration rate values in recipients 1 to 6 y after transplantation.

RESULTS

In total, 2177 donors and 3638 corresponding kidney graft recipients were included. Twenty-four percent of the donors (n = 520) were exposed to contrast medium, corresponding to 23% of recipients (n = 832). DGF was observed in 36% (n = 1321) and primary nonfunction in 3% (n = 122) of recipients. DGF rates for donation after brain death (DBD) and donation after circulatory death (DCD) donors showed no significant effect of contrast medium exposure ( P  = 0.15 and P  = 0.60 for DBD and DCD donors, respectively). In multivariable analyses, contrast medium administration was not significantly associated with a higher DGF risk (odds ratio 1.06; 95% confidence interval, 0.86-1.36; P  = 0.63) nor was a significant predictor for death-censored graft failure (hazard ratio 1.01; 95% confidence interval, 0.77-1.33; P  = 0.93). Linear mixed models showed no difference in mean estimated glomerular filtration rate values in recipients 1 to 6 y posttransplantation ( P  = 0.78).

CONCLUSIONS

This study indicates that contrast medium administration in DBD and DCD donors has no negative effect on early and long-term kidney graft function.

Characteristics of donor lungs declined on site and impact of lung allocation policy change

OBJECTIVE

National and institutional data suggest an increase in organ discard rate (donor lungs procured but not implanted) after a new lung allocation policy was introduced in 2017. However, this measure does not include on-site decline rate (donor lungs declined intraoperatively). The objective of this study is to examine the impact of the allocation policy change on on-site decline.

METHODS

We used a Washington University (WU) and our local organ procurement organization (Mid-America Transplant [MTS]) database to abstract data on all accepted lung offers from 2014 to 2021. An on-site decline was defined as an event in which the procuring team declined the organs intraoperatively, and the lungs were not procured. Logistic regression models were used to investigate potentially modifiable reasons for decline.

RESULTS

The overall study cohort comprised 876 accepted lung offers, of which 471 donors were at MTS with WU or others as the accepting center and 405 at other organ procurement organizations with WU as the accepting center. At MTS, the on-site decline rate increased from 4.6% to 10.8% (P = .01) after the policy change. Given the greater likelihood of non-local organ placement and longer travel distance after policy change, the estimated cost of each on-site decline increased from $5727 to $9700. In the overall group, latest partial pressure of oxygen (odds ratio [OR], 0.993; 95% confidence interval [CI], 0.989-0.997), chest trauma (OR, 2.474; CI, 1.018-6.010), chest radiograph abnormality (OR, 2.902; CI, 1.289-6.532), and bronchoscopy abnormality (OR, 3.654; CI, 1.813-7.365) were associated with on-site decline, although lung allocation policy era was unassociated (P = .22).

CONCLUSIONS

We found that nearly 8% of accepted lungs are declined on site. Several donor factors were associated with on-site decline, although lung allocation policy change did not have a consistent impact on on-site decline.

Ultrasound Scanning in Lung Procurement. Protocol for Decision-Making With the Purpose of Increasing Transplant Eligible Lungs

BACKGROUND

The main obstacle to obtaining lungs for transplantation is the shortage of donors. Once potential donors have been offered to transplant programs, the acceptance rate is highly variable, ranging from 5% to 20%. Minimizing donor leakage by converting potential lung donors into real donors is one of the key elements to improve results, and it is essential to have tools that facilitate decision-making in this scenario. The selection and rejection of transplantation-eligible lungs are usually made with chest x-rays; however, lung ultrasound scanning has shown better sensitivity and specificity for diagnosing pulmonary pathologies. Lung ultrasound scanning allows us to identify the reversible causes of low PaO2/fraction of inspired oxygen (FIO2) ratio, thus enabling the establishment of specific interventions, which, if proved successful, could turn lungs into transplant-eligible lungs. The available literature on its use in managing brain death donors and lung procurement is extremely scarce.

METHODS

A simple protocol aimed at identifying and treating the main reversible causes of low PaO2/FIO2 ratio to aid in decision-making is presented in this paper.

CONCLUSION

Lung ultrasound is a powerful, useful, and cheap technique available at the donor's bedside. It is conspicuously underused, despite being potentially helpful in decision-making by minimizing the discarding of donors, thus probably increasing the number of lungs sui for transplantation.

CT-based Machine Learning for Donor Lung Screening Prior to Transplantation

Background

Assessment and selection of donor lungs remains largely subjective and experience based. Criteria to accept or decline lungs are poorly standardized and are not compliant with the current donor pool. Using ex vivo CT images, we investigated the use of a CT-based machine learning algorithm for screening donor lungs prior to transplantation.

Methods

Clinical measures and ex-situ CT scans were collected from 100 cases as part of a prospective clinical trial. Following procurement, donor lungs were inflated, placed on ice according to routine clinical practice, and imaged using a clinical CT scanner prior to transplantation while stored in the icebox. We trained and tested a supervised machine learning method called dictionary learning , which uses CT scans and learns specific image patterns and features pertaining to each class for a classification task. The results were evaluated with donor and recipient clinical measures.

Results

Of the 100 lung pairs donated, 70 were considered acceptable for transplantation (based on standard clinical assessment) prior to CT screening and were consequently implanted. The remaining 30 pairs were screened but not transplanted. Our machine learning algorithm was able to detect pulmonary abnormalities on the CT scans. Among the patients who received donor lungs, our algorithm identified recipients who had extended stays in the ICU and were at 19 times higher risk of developing CLAD within 2 years post-transplant.

Conclusions

We have created a strategy to ex vivo screen donor lungs using a CT-based machine learning algorithm. As the use of suboptimal donor lungs rises, it is important to have in place objective techniques that will assist physicians in accurately screening donor lungs to identify recipients most at risk of post-transplant complications.

Potential Role of Computed Tomography Volumetry in Size Matching in Lung Transplantation

BACKGROUND

Accumulated knowledge on the outcomes related to size mismatch in lung transplantation derives from predicted total lung capacity equations rather than individualized measurements of donors and recipients. The increasing availability of computed tomography (CT) makes it possible to measure the lung volumes of donors and recipients before transplantation. We hypothesize that CT-derived lung volumes predict a need for surgical graft reduction and primary graft dysfunction.

METHODS

Donors from the local organ procurement organization and recipients from our hospital from 2012 to 2018 were included if their CT exams were available. The CT lung volumes and plethysmography total lung capacity were measured and compared with predicted total lung capacity using Bland Altman methods. We used logistic regression to predict the need for surgical graft reduction and ordinal logistic regression to stratify the risk for primary graft dysfunction.

RESULTS

A total of 315 transplant candidates with 575 CT scans and 379 donors with 379 CT scans were included. The CT lung volumes closely approximated plethysmography lung volumes and differed from the predicted total lung capacity in transplant candidates. In donors, CT lung volumes systematically underestimated predicted total lung capacity. Ninety-four donors and recipients were matched and transplanted locally. Larger donor and smaller recipient lung volumes estimated by CT predicted a need for surgical graft reduction and were associated with higher primary graft dysfunction grade.

CONCLUSION

The CT lung volumes predicted the need for surgical graft reduction and primary graft dysfunction grade. Adding CT-derived lung volumes to the donor-recipient matching process may improve recipients' outcomes.

The 20-year paradigm shift toward organ recovery centers: 2500 donors at Mid-America Transplant and broader adoption across the United States

On March 1, 2001, Mid-America Transplant, the organ procurement organization (OPO) located in St Louis, Missouri, performed the first organ recovery of a brain-dead donor in a hospital-independent, free-standing, organ recovery center (ORC), with successful transplantation of a liver. This was the inception of a paradigm shift in donor management and organ procurement, moving away from the traditional method of using the donor hospital. In the last 20 years, many advances have occurred in the ORC. Brain-dead donors are moved within hours of authorization to fully equipped intensive care units. Some ORCs are equipped with computed tomography scanners, portable radiography, laboratory facilities, bronchoscopy, and a cardiac catheterization laboratory. ORCs have dedicated surgical suites, and operating time is frequently during the day and is rarely delayed. Donor management in an ORC is more consistent, efficient, and effective than that in a donor hospital, and studies have demonstrated increased organ yield. Multiple studies have demonstrated a cost benefit of an ORC as well as providing an ideal environment for donor research studies. Currently, there are 24 of 57 OPOs that are using an independent or hospital-based ORC to manage their donors. We review the history and describe the current state of ORCs.

The role of radiology in addressing the challenge of lung cancer after lung transplantation

The importance of lung cancer as a complication of lung transplantation is increasingly recognised. It may become an important survival-limiting factor in lung transplant patients as management of other complications continues to improve and utilisation of extended criteria donors grows. Radiology can play a key role in tackling this issue at multiple stages in the transplantation pathway and follow-up process. Routine chest CT as part of pre-transplant recipient assessment (and donor assessment if available) can identify suspicious lung lesions with high sensitivity and detect chronic structural lung diseases such as pulmonary fibrosis associated with an increased risk of malignancy post-transplant. Pre-transplant CT also provides a comparison for later CT studies in the assessment of nodules or masses. The potential role of regular chest CT for lung cancer screening after transplantation is less certain due to limited available evidence on its efficacy. Radiologists should be cognisant of how the causes of pulmonary nodules in lung transplant patients may differ from the general population, vary with time since transplantation and require specific recommendations for further investigation/follow-up as general guidelines are not applicable. As part of the multidisciplinary team, radiology is involved in an aggressive diagnostic and therapeutic management approach for nodular lung lesions after transplant both through follow-up imaging and image-guided tissue sampling. This review provides a comprehensive overview of available clinical data and evidence on lung cancer in lung transplant recipients, and in particular an assessment of the current and potential roles of pre- and post-transplant imaging. KEY POINTS: • Lung cancer after lung transplantation may become an increasingly important survival-limiting factor as mortality from other complications declines. • There are a number of important roles for radiology in tackling the issue which include pre-transplant CT and supporting an aggressive multidisciplinary management strategy where lung nodules are detected in transplant patients. • The introduction of routine surveillance chest CT after transplant in addition to standard clinical follow-up as a means of lung cancer screening should be considered.

Centralized Organ Recovery and Reconditioning Centers

An increased focus on improving efficiency and decreasing costs has resulted in alternative models of donor management and organ recovery. The specialized donor care facility model provides highly efficient and cost-effective donor care at a free-standing facility, resulting in improved organ yield, shorter ischemic times, decreased travel, and fewer nighttime operations. Ex vivo lung perfusion (EVLP) improves utilization of extended criteria donor lungs, and centralized EVLP facilities have the potential to increase transplant volumes for smaller transplant programs in specified geographic regions. These alternative models are increasingly being used in the United States to improve waitlist mortality and combat the ongoing donor organ shortage.

Management of the Potential Lung Donor

The use of donor management protocols has significantly improved recovery rates; however, the inherent instability of lungs after death results in low utilization rates of potential donor lungs. Donor lungs are susceptible to direct trauma, aspiration, neurogenic edema, ventilator-associated barotrauma, and ventilator-associated pneumonia. After irreversible brain injury and determination of futility of care, the goal of medical management of the donor shifts to maintaining hemodynamic stability and maximizing the likelihood of successful organ recovery.

Advanced considerations in organ donors

The rising need for lung transplantation over recent years has not paralleled the availability of suitable lung allografts. The number of lung transplantations performed each year in the United States remains limited by an inadequate supply of suitable donors as well as low donor utilization rates. While several methods have been proposed for increasing the donor pool, there is considerable disparity between acceptance and utilization of these practices among transplant centers. In this review article, we explore various approaches for enhancing donor selection and expanding the donor pool. We discuss the use of “extended criteria” donors including high risk groups such as drug overdose donors, and we examine the role of techniques in donor assessment and selection such as the use of computed tomography for accurate size matching. We review topics in donor management such as the establishment of specialized donor care facilities and the implementation of lung-focused resuscitation protocols, and we discuss advancements in donor procurement such as the utilization of local procurement teams. We also review barriers to donation, such as variability in organ procurement organization (OPO) consent practices, as well as patient-specific factors such as religious or cultural beliefs. Addressing these aspects of donor evaluation, management, and accessibility is essential in maximizing the number of lungs available for transplantation within the existing donor pool.

Successful lung transplantation after prone positioning in an ineligible donor: a case report

Atelectasis is a reversible factor in hypoxemia among brain-dead donors. In ineligible donors, prone positioning reverses atelectasis and improves oxygenation. We present a successful lung transplantation after salvaging a previously unviable lung. A 37-year-old woman presented with acute pontine hemorrhage that progressed to brain death. The initial partial pressure of oxygen (PaO₂)/fraction of inspired oxygen (FiO₂) ratio of the donor’s lung was 342 mmHg. The PaO₂/FiO₂ ratio dropped to 49 mmHg due to atelectasis. There was no improvement despite recruitment maneuvers, bronchoscopy, and chest percussion. After placing the donor in the prone position for four hours, electrical impedance tomography showed improved atelectasis. The donor did not experience hemodynamic instability. The lung was transplanted into a patient with Kartagener’s syndrome with situs inversus. The surgical procedure was uneventful. He was successfully weaned from the mechanical ventilator on the second-day post-transplantation and was discharged from the hospital after 4 weeks.

Specialized Donor Care Facility Model and Advances in Management of Thoracic Organ Donors

BACKGROUND

Donor hearts and lungs are more susceptible to the inflammatory physiologic changes that occur after brain death. Prior investigations have shown that protocolized management of potential organ donors can rehabilitate donor organs that are initially deemed unacceptable. In this review we discuss advances in donor management models with particular attention to the specialized donor care facility model. In addition we review specific strategies to optimize donor thoracic organs and improve organ yield in thoracic transplantation.

METHODS

We performed a literature review by searching the PubMed database for medical subject heading terms associated with organ donor management models. We also communicated with our local organ procurement organization to gather published and unpublished information first-hand.

RESULTS

The specialized donor care facility model has been shown to improve the efficiency of organ donor management and procurement while reducing costs and minimizing travel and its associated risks. Lung protective ventilation, recruitment of atelectatic lung, and hormone therapy (eg, glucocorticoids and triiodothyronine/thyroxine) are associated with improved lung utilization rates. Stroke volume-based resuscitation is associated with improved heart utilization rates, whereas studies evaluating hormone therapy (eg, glucocorticoids and triiodothyronine/thyroxine) have shown variable results.

CONCLUSIONS

Lack of high-quality prospective evidence results in conflicting practices across organ procurement organizations, and best practices remain controversial. Future studies should focus on prospective, randomized investigations to evaluate donor management strategies. The specialized donor care facility model fosters a collaborative environment that encourages academic inquiry and is an ideal setting for these investigations.

Bacterial products in donor airways prevent the induction of lung transplant tolerance

Although postoperative bacterial infections can trigger rejection of pulmonary allografts, the impact of bacterial colonization of donor grafts on alloimmune responses to transplanted lungs remains unknown. Here, we tested the hypothesis that bacterial products present within donor grafts at the time of implantation promote lung allograft rejection. Administration of the toll-like receptor 2 (TLR2) agonist Pam₃ Cys₄ to Balb/c wild-type grafts triggered acute cellular rejection after transplantation into B6 wild-type recipients that received perioperative costimulatory blockade. Pam₃ Cys₄ -triggered rejection was associated with an expansion of CD8⁺ T lymphocytes and CD11c⁺ CD11b^hi MHC (major histocompatibility complex) class II⁺ antigen-presenting cells within the transplanted lungs. Rejection was prevented when lungs were transplanted into TLR2-deficient recipients but not when MyD88-deficient donors were used. Adoptive transfer of B6 wild-type monocytes, but not T cells, following transplantation into B6 TLR2-deficient recipients restored the ability of Pam₃ Cys₄ to trigger acute cellular rejection. Thus, we have demonstrated that activation of TLR2 by a bacterial lipopeptide within the donor airways prevents the induction of lung allograft tolerance through a process mediated by recipient-derived monocytes. Our work suggests that donor lungs harboring bacteria may precipitate an inflammatory response that can facilitate allograft rejection.

Donor management using a specialized donor care facility is associated with higher organ utilization from drug overdose donors

Drug overdoses have tripled in the United States over the last two decades. With the increasing demand for donor organs, one potential consequence of the opioid epidemic may be an increase in suitable donor organs. Unfortunately, organs from donors dying of drug overdose have poorer utilization rates than other groups of brain-dead donors, largely due to physician and recipient concerns about viral disease transmission. During the study period of 2011 to 2016, drug overdose donors (DODs) account for an increasingly greater proportion of the national donor pool. We show that a novel model of donor care, known as specialized donor care facility (SDCF), is associated with an increase in organ utilization from DODs compared to the conventional model of hospital-based donor care. This is likely related to the close relationship of the SDCF with the transplant centers, leading to improved communication and highly efficient donor care.

Ventilation in the prone position improves oxygenation and results in more lungs being transplanted from organ donors with hypoxemia and atelectasis

BACKGROUND

Hypoxemia is the most common barrier to lungs being transplanted from eligible organ donors who are brain dead (BD). Atelectasis is the principal reversible contributing factor to hypoxemia after brain death. We evaluated prospectively whether ventilation in the prone position in donors who are BD would reverse atelectasis, improve oxygenation, and result in more lungs being transplanted.

METHODS

Organ donors managed at the recovery center of 1 organ procurement organization over a 2-year period who exhibited hypoxemia (partial pressure of arterial oxygen [PaO₂]/fraction of inspired oxygen of <300 mm Hg) and had evidence of atelectasis were ventilated in the prone position for 12 hours or longer during donor management. A subset underwent computed tomography (CT) imaging to quantify the degree of atelectasis before and after prone positioning. Outcomes were compared with those of a control group with hypoxemia and atelectasis managed similarly but in the supine position in the previous 2 years.

RESULTS

A total of 40 lung-eligible donors who were BD with hypoxemia and atelectasis were managed in a prone position and compared with 79 donors in supine position. Baseline PaO₂ was similar between the prone and the supine groups (194 ± 78 vs 177 ± 77 mm Hg, p = 0.26) but increased more in the prone group at 4 hours (by 113 vs 54 mm Hg, p = 0.001) and remained 74-mm Hg higher at 12 hours (340 vs 266 mm Hg, p = 0.0006). CT-graded atelectasis was significantly reduced after ventilation in the prone position but persisted in the supine group (p = 0.001). Final PaO₂ was not significantly higher (344 vs 306, p = 0.12), but lungs were more often transplanted in the prone group (45% vs 24%, p = 0.03).

CONCLUSIONS

Ventilation in the prone position reverses atelectasis and rapidly and sustainably improves oxygenation in organ donors who are BD with hypoxemia. This effect appears to translate into more lungs being transplanted.

Clinical Outcomes of Lung Transplants From Donors With Unexpected Pulmonary Embolism

BACKGROUND

Pulmonary embolism (PE) is unexpectedly detected in some donor lungs during organ procurement for lung transplantation. Anecdotally, such lungs are usually implanted; however, the impact of this finding on recipient outcomes remains unclear. We hypothesized that incidentally detected donor PE is associated with adverse short-term and long-term outcomes among lung transplant recipients.

METHODS

We analyzed a prospectively maintained database of all lung donors procured by a single surgeon and transplanted at our institution between 2009 and 2018. A standardized approach was used for all procurements and included antegrade and retrograde flush. Pulmonary embolism was defined as macroscopic thrombus seen in the pulmonary artery during the donor procurement operation.

RESULTS

A total of 501 consecutive lung procurements were performed during the study period. The incidence of donor PE was 4.4% (22 of 501). No organs were discarded owing to PE. Donors with PE were similar to donors without PE in baseline characteristics and Pao₂. Recipients in the two groups were also similar. Pulmonary embolism was associated with a higher likelihood of acute cellular rejection grade 2 or more (10 of 22 [45.5%] vs 120 of 479 [25.1%], P = .03). Multivariable Cox modeling demonstrated an association between PE and the development of chronic lung allograft dysfunction (hazard ratio 2.02; 95% confidence interval, 1.23 to 3.30; P = .005).

CONCLUSIONS

Lungs from donors with incidentally detected PE may be associated with a higher incidence of recipient acute cellular rejection as well as reduced chronic lung allograft dysfunction-free survival. Surgeons must use caution when transplanting lungs with incidentally discovered PE. These preliminary findings warrant corroboration in larger data sets.

Histopathologic and radiologic assessment of nontransplanted donor lungs

Donor organ shortage results in significant waiting list mortality. Donor lung assessment is currently based on donors' history, gas exchange, chest X-ray, bronchoscopy findings, and ultimately in situ inspection but remains subjective. We correlated histopathology and radiology in nontransplanted donor lungs with the clinical indications to decline the offered organ. Sixty-two donor lungs, not used for transplantation (2010-2019), were procured, air-inflated, frozen, scanned with computed tomography, systematically sampled, and histologically and radiologically assessed. Thirty-nine (63%) lungs were declined for allograft-related reasons. In 13/39 (33%) lungs, histology could not confirm the reason for decline, in an additional 8/39 (21%) lungs, histologic abnormalities were only considered mild. In 16/39 (41%) lungs, radiology could not confirm the reason for decline. Twenty-three (37%) donor lungs were not transplanted due to extrapulmonary causes, of which three (13%) lungs displayed severe histologic abnormalities (pneumonia, n = 2; emphysema, n = 1), in addition to mild emphysema in 9 (39%) lungs and minor bronchopneumonia in 1 (4%). Radiology revealed ground-glass opacities in 8/23 (35%) and emphysema in 4/23 (17%) lungs. Histopathologic and radiologic assessment of nontransplanted donor lungs revealed substantial discrepancy with the clinical reason for decline. Optimization of donor lung assessment is necessary to improve current organ acceptance rates.

Ex vivo lung CT findings may predict the outcome of the early phase after lung transplantation

Purpose

We developed an ex vivo lung CT (EVL-CT) technique that allows us to obtain detailed CT images and morphologically assess the retrieved lung from a donor for transplantation. After we recovered the lung graft from a brain-dead donor, we transported it to our hospital and CT images were obtained ex vivo before lung transplant surgery. The objective of this study was to investigate the correlation between the EVL-CT findings and post-transplant outcome in patients who underwent bilateral lung transplantation (BLT) or single lung transplantation (SLT).

Methods

We retrospectively reviewed the records of 70 patients with available EVL-CT data who underwent BLT (34 cases) or SLT (36 cases) in our hospital between October 2007 and September 2017. The recipients were divided into 2 groups (control group, infiltration group) according to the findings of EVL-CT of the lung graft in BLT and SLT, respectively. Recipients in the control group were transplanted lung grafts without any infiltrates (BLT control group, SLT control group). Recipients in the infiltration group received lung grafts with infiltrates (BLT infiltration group, SLT infiltration group).

Results

The recipients in the BLT infiltration group showed significantly slower recovery from primary graft dysfunction and a longer mechanical ventilation period and ICU stay period than those in the BLT control group. The mechanical ventilation period was significantly longer in the recipients in the SLT infiltration group than those in the SLT control group.

Conclusion

EVL-CT may predict the outcome of the early phase after lung transplantation.