Imaging Course of Lung Transplantation: From Patient Selection to Postoperative Complications

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.

Pulmonary transplant complications: a radiologic review

Lung transplantation has become the definitive treatment for end stage respiratory disease. Numbers and survival rates have increased over the past decade, with transplant recipients living longer and with greater comorbidities, resulting in greater complexity of care. Common and uncommon complications that occur in the immediate, early, intermediate, and late periods can have significant impact on the course of the transplant. Fortunately, advancements in surgery, medical care, and imaging as well as other diagnostics work to prevent, identify, and manage complications that would otherwise have a negative impact on survivability. This review will focus on contextualizing complications both categorically and chronologically, with highlights of specific imaging and clinical features in order to inform both radiologists and clinicians involved in post-transplant care.

Special Considerations and Techniques of Interventions in Lung Transplant Recipients

Lung transplant remains an important treatment option for patients with end-stage lung diseases providing improvement in survival rates and quality of life. Specialized considerations should be applied with interventions of lung transplant recipients as they host specific anatomic variations and high risk towards certain complications. In this article, we highlight the role of interventional radiology for lung transplant recipients along with discussion of interventional techniques. Specific emphasis is placed on describing and explaining the techniques pertained to the points of anastomosis, diagnosis and treatment of malignancies, and management of complications in lung transplant recipients.

Early chest CT abnormalities to predict the subsequent occurrence of chronic lung allograft dysfunction

INTRODUCTION

Chronic lung allograft dysfunction (CLAD) can take two forms: bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS). The aim was to determine if chest-CT abnormalities after lung transplantation (LTx) could predict CLAD before respiratory functional deterioration.

MATERIALS AND METHODS

This monocentric retrospective study analyzed consecutive patients who underwent LTx from January 2015 to December 2018. Initial CT post-LTx (CTi) and a follow-up CT at least 9 months post-LTx (CTf) were reviewed. CLAD was defined as a persistent respiratory functional decline (> 20% of basal FEV1) outside acute episode. A Cox regression was performed in univariate, then in multivariate analysis (including features with p < 0.01 in univariate or of clinical importance) to determine risk factors for CLAD. Subgroup analyses were made for BOS, RAS, and death.

RESULTS

Among 118 LTx patients (median (min-max) 47 (18-68) years), 25 developed CLAD during follow-up (19 BOS). The median time to CLAD since LTx was 570 days [150-1770]. Moderate pulmonary artery stenosis (30-50%) was associated with the occurrence of CLAD on CTi (hazard ratio HR = 4.6, CI [1.6-13.2]) and consolidations and pleural effusion on CTf (HR = 2.6, CI [1.3-4.9] and HR = 4.5, CI [1.5-13.6] respectively). The presence of mosaic attenuation (HR = 4.1, CI [1.4-12.5]), consolidations (HR = 2.6, CI [1.3-5.4]), and pleural effusions (p = 0.01, HR = 5.7, CI [1.4-22.3]) were risk factors for BOS on CTf. The consolidations (p = 0.029) and pleural effusions (p = 0.001) were risk factors for death on CTf.

CONCLUSIONS

CTi and CTf in the monitoring of LTx patients could predict CLAD. Moderate pulmonary artery stenosis, mosaic pattern, parenchyma condensations, and pleural effusions were risk factors for CLAD.

CRITICAL RELEVANCE STATEMENT

There is a potential predictive role of chest CT in the follow-up of LTx patients for chronic lung allograft dysfunction (CLAD). Early chest CT should focus on pulmonary artery stenosis (risk factor for CLAD in this study). During the follow-up (at least 9 months post-LTx), parenchymal consolidations and pleural effusions were shown to be risk factors for CLAD, and death in subgroup analyses.

KEY POINTS

• Pulmonary artery stenosis (30-50%) on initial chest-CT following lung transplantation predicts CLAD HR = 4.5; CI [1.6-13.2]. • Pleural effusion and consolidations 1 year after lung transplantation predict CLAD and death. • Early evaluation of lung transplanted patients should evaluate pulmonary artery anastomosis.

Complicações dos transplantes pulmonares na tomografia computadorizada: ensaio iconográfico

Resumo Transplantes pulmonares são procedimentos progressivamente mais realizados em todo o mundo como opção para tratamento de doenças pulmonares em estágio terminal. Apesar dos avanços laboratoriais, da técnica cirúrgica e da seleção de doadores e receptores, a mortalidade nesses procedimentos ainda é significativa, em razão de complicações típicas dos pacientes transplantados. Este trabalho consiste em uma revisão da literatura acerca do tema, ilustrando as complicações abordadas por meio de imagens de tomografia computadorizada.

Complications of lung transplantation on computed tomography: pictorial essay

Lung transplantation is becoming increasingly more common as an alternative treatment for end-stage lung disease. Despite advances in laboratory testing, surgical technique, and donor/recipient selection, lung transplantation is still associated with significant mortality, due to postoperative complications. This paper consists of a brief review of postoperative complications in lung transplant recipients, illustrating those complications with computed tomography images.

Imaging of pulmonary infections after lung transplantation: a pictorial essay of early and late computed tomography findings

Pulmonary infections are among the most common complications after lung transplants and a major cause of morbidity and mortality in these patients. Computed tomography is one of the main non-invasive diagnostic tools for detecting lung infections but characterizing the correct etiology may be very challenging. Indeed, although several pathogens show typical patterns at imaging, others, such as bacteria, may demonstrate quite unspecific features. Therefore, additional parameters, like the timing of the infection, should be evaluated to support the radiologists in narrowing the differential diagnoses. In fact, it has been demonstrated that several pathogens, like Candida albicans, usually occurring within the first month after the transplant, frequently occur at specific time points. Thus, aim of this review is to make radiologists and clinicians familiar with the computed tomography patterns of pulmonary infections occurring after lung transplant, considering the etiology and the time of onset, according to the extensive experience gained in our tertiary center.