Diagnosis and interventions of vascular complications in lung transplant

Pulmonary Embolism Following Lung Transplantation: Prevention and Management

Thromboembolic events are the third leading cardiovascular diagnosis following stroke and myocardial infarction. In the United States, 300,000 to 600,000 people per year are diagnosed with venous thromboembolism, either deep venous thrombosis or pulmonary embolism (PE). Of those patients, thousands die from PE despite heightened vigilance and improved therapies. Lung transplant recipients are at increased risk of developing PE due to multiple risk factors unique to this population. Additionally, the transplant recipients are more susceptible to morbid complications from PE. As a result, prevention, timely recognition, and intervention of PE in the lung transplant population are of the utmost importance.

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.

Surgical Complications After Lung Transplantation: The Reina Sofía Hospital Experience

OBJECTIVE

To assess the incidence of surgical complications after lung transplantation and its influence on early mortality and long-term survival.

METHODS

Retrospective review of 792 lung transplants (LTs) performed from 1994 to 2022. Among them, 769 with complete data were selected. Patients with and without surgical complications were compared by univariable and multivariable analyses.

RESULTS

There were 385 single LTs (50%), 371 double LTs (48%), 8 bilobar LTs (1%), and 5 combined liver LTs (1%). Two hundred forty-nine patients presented surgical complications (32%) as follows: bronchial (n = 61), vascular (n = 55), pneumothorax (n = 33), and phrenic nerve palsy (n = 22). Thirty-day mortality (noncomplicated vs complicated) was 57 (41%) vs 80 (59%), P < .001. Transplants for bronchiectasis (58%), pulmonary hypertension (50%), and re-transplants (78%) presented more surgical complications (P < .001). Double LT (40%), bilobar LT (88%), and combined liver LT (100%) presented more surgical complications (P < .001). Complicated recipients were younger (49 ± 15 vs 45 ± 17 years; P = .001), with longer ischemic times (429 ± 67 vs 450 ± 76 min [2nd graft]; P = .007), and required extracorporeal support (ECLS) more often (43% vs 57%; P < .001). Survival at 1, 5, 10, 15, and 20 years (noncomplicated vs complicated): 78%, 63%, 52%, 41%, 31% vs 52%, 42%, 35%, 26%, 22%; P < .001). Predictors of mortality were the need for ECLS (odds ratio [OR] 4.14; P < .001), postoperative ventilation (hours) (OR 1.01; P < .001), and vascular complications (OR 4.78; P < .001).

CONCLUSION

Surgical complications remain an important source of morbidity and mortality after lung transplantation. Complex surgical procedures requiring ECLS develop frequent surgical complications needing long postoperative ventilation that are associated with early mortality and poorer long-term survival.

Wireless pulmonary artery sensor implantation in a unilateral lung transplant recipient

Patients with lung transplantation can have concomitant left ventricular failure which can either precede the lung transplantation or develop after. Implantable wireless pulmonary artery (PA) pressure monitors to guide hemodynamic management in heart failure such as the CardioMEMS device (Abbott, Sylmar, CA, USA) have been shown to improve outcomes. However, in a lung transplant recipient there are unique physiological and practical considerations when contemplating to implant a PA pressure sensor such as safety of implanting the device, choice of site of implantation, accuracy of wedge tracings to calibrate, and exclusion of vascular stenoses post transplantation. We discuss these considerations in the context of a man in his early 60s with a known left lung transplant two years previously who developed worsening heart failure needing invasive monitoring. Right lung PA sensor placement was considered, but on selective pulmonary angiography the right PA was found to be of small caliber and with significant tortuosity. After careful hemodynamic assessment, the PA sensor was implanted in the PA of the transplanted lung which is the first such case to our knowledge.

Learning objective

We report the first documented case of an implantable wireless pulmonary artery pressure monitor (CardioMEMs) into a transplanted lung. Device-related complications, such as pulmonary artery injury, infection, and hemoptysis, must be assessed after placement. Given the changes in pulmonary artery pressures after lung transplantation, recalibration of the CardioMEMs device may need to be considered if placed within first year of transplant.

Imaging in Lung Transplantation: Surgical Techniques and Complications

Lung transplant is an established treatment for patients with end-stage lung disease. As a result, there is increased demand for transplants. Despite improvements in pretransplant evaluation, surgical techniques, and postsurgical care, the average posttransplant life expectancy is only around 6.5 years. Early recognition of complications on imaging and treatment can improve survival. Knowledge of surgical techniques and imaging findings of surgical and nonsurgical complications is essential. This review covers surgical techniques and imaging appearance of postsurgical and nonsurgical complications, including allograft dysfunction, infections, neoplasms, and recurrence of primary lung disease.

Mismatched Perfusion Defects on Routine Ventilation-Perfusion Scans after Lung Transplantation

BACKGROUND

Incidental pulmonary embolism (PE) is a challenging entity with unclear treatment implications. Our program performs routine ventilation-perfusion (VQ) scans at 3-months post-transplant to establish airway and vascular function. We sought to determine the prevalence and prognostic implications of mismatched perfusion defects (MMPD) found on these studies, hypothesizing they would be associated with a benign prognosis.

METHODS

We studied VQ scans obtained routinely at 3-months post-transplant from double lung transplant recipients 2005-2016 for studies with MMPD interpreted as high or intermediate probability for PE. We tested the relationship between MMPD and 1-year survival via chi square testing, overall survival via Kaplan Meier analysis with log rank testing and peak forced expiratory volume in 1 second (FEV1) percent predicted via t-testing.

RESULTS

373 patients met inclusion criteria, of whom 35 (9%) had VQ scans with MMPDs interpreted by radiologists as high or intermediate probability for PE. Baseline recipient and donor characteristics were similar between groups. 7 patients (20%) in the MMPD group were treated with therapeutic anticoagulation. Patients with MMPD had similar 1-year survival (100% vs. 98%, p = 1.00), overall survival (log rank p = 0.90) and peak FEV1% predicted (94% [SD 20%] vs. 92% [SD 21%]; p = 0.58). Anticoagulation did not affect these relationships.

CONCLUSION

Mismatched perfusion defects on routine post-transplant VQ scan were not associated with a difference in survival or lung function. A conservative approach to these changes may be a viable option in the absence of other anticoagulation indications. This article is protected by copyright. All rights reserved.

Complications of Lung Transplantation: Update on Imaging Manifestations and Management

As lung transplantation has become the most effective definitive treatment option for end-stage chronic respiratory diseases, yearly rates of this surgery have been steadily increasing. Despite improvement in surgical techniques and medical management of transplant recipients, complications from lung transplantation are a major cause of morbidity and mortality. Some of these complications can be classified on the basis of the time they typically occur after lung transplantation, while others may occur at any time. Imaging studies, in conjunction with clinical and laboratory evaluation, are key components in diagnosing and monitoring these conditions. Therefore, radiologists play a critical role in recognizing and communicating findings suggestive of lung transplantation complications. A description of imaging features of the most common lung transplantation complications, including surgical, medical, immunologic, and infectious complications, as well as an update on their management, will be reviewed here. Keywords: Pulmonary, Thorax, Surgery, Transplantation Supplemental material is available for this article. © RSNA, 2021.

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

Lung transplant is increasingly performed for the treatment of end-stage lung disease. As the number of lung transplants and transplant centers continues to rise, radiologists will more frequently participate in the care of patients undergoing lung transplant, both before and after transplant. Potential donors and recipients undergo chest radiography and CT as part of their pretransplant assessment to evaluate for contraindications to transplant and to aid in surgical planning. After transplant, recipients undergo imaging during the postoperative hospitalization and also in the long-term outpatient setting. Radiologists encounter a wide variety of conditions leading to end-stage lung disease and a myriad of posttransplant complications, some of which are unique to lung transplantation. Familiarity with these pathologic conditions, including their imaging findings and their temporal relationship to the transplant, is crucial to accurate radiologic interpretation. Knowledge of the surgical techniques and expected postoperative appearance prevents confusing normal posttransplant imaging findings with complications. A basic understanding of the indications, contraindications, and surgical considerations of lung transplant aids in imaging interpretation and protocoling and also facilitates communication between radiologists and transplant physicians. Despite medical and surgical advances over the past several decades, lung transplant recipients currently have an average posttransplant life expectancy of only 6.7 years. As members of the transplant team, radiologists can help maximize patient survival and hopefully increase posttransplant life expectancy and quality of life in the coming decades. ^©RSNA, 2021 An invited commentary by Bierhals is available online. Online supplemental material is available for this article.

Cardiovascular complications in cystic fibrosis: A review of the literature

Cystic fibrosis is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, leading to dysfunction of the CFTR protein. CFTR dysfunction leads to disease in the respiratory and gastrointestinal systems. Disorders of the cardiovascular system in individuals with CF are usually attributed to secondary effects from progressive lung disease. However, CFTR has been localized to vascular endothelium and smooth muscle, suggesting that CFTR dysfunction may directly impact cardiovascular function. As treatments for CF improve and life-expectancy increases, the risk of vascular disease may increase in prevalence related to primary and secondary CFTR dysfunction, chronic systemic inflammation, nutritional health and hyperglycemia in individuals with CF related diabetes. Here we review the available literature on CF and the cardiovascular system, examining the secondary effects and evidence for direct CFTR dysfunction in the heart, aorta, pulmonary vessels, and vasculature, as well as future directions and treatment options.

Early postoperative complications in lung transplant recipients

Lung transplantation has become an established therapy for end-stage lung diseases. Early postoperative complications can impact immediate, mid-term, and long-term outcomes. Appropriate management, prevention, and early detection of these early postoperative complications can improve the overall transplant course. In this review, we highlight the incidence, detection, and management of these early postoperative complications in lung transplant recipients.