Diagnosis and interventions of vascular complications in lung transplant

Abstract

Though rare, pulmonary vascular complications after lung transplantation carry high morbidity and mortality. Knowledge of the normal and abnormal appearance of lung transplant vasculature is essential for timely and appropriate diagnosis and management of complications. Appropriate selection of surgical and endovascular treatments depend on the availability of expertise and requires a multidisciplinary approach to ensure the best outcomes.

Keywords: Transplantation; anastomosis; stent; thrombosis; vascular.

Figure 1

An illustration of normal pulmonary arterial anastomosis. (A) Normal appearance the pulmonary arterial anastomoses with thin folds (orange arrows) and no significant change in caliber. CT images (B,C) demonstrate mild caliber change of the right and left pulmonary arterial anastomoses consistent with normal folds (red arrows). PT, main pulmonary artery; RPA, right pulmonary artery; LPA, Left pulmonary artery; A, aorta; SVC, superior vena cava; DA, descending aorta; RB, right main bronchus; LB, left main bronchus; E, esophagus; AZ, azygous vein.

Figure 2

An illustration of normal and stenotic pulmonary venous anastomosis. (A) Normal appearance of pulmonary venous anastomosis; (B) left inferior pulmonary venous anastomotic stenosis (black arrow). PV, pulmonary vein; LA, left atrium.

Figure 3

Pulmonary arterial anastomotic stenosis. (A) Right pulmonary arterial anastomotic stenosis with significant narrowing and poststenotic dilatation (yellow arrow); (B) left PA anastomosis with moderate stenosis is seen on contrast enhanced CT (red arrow). PT, main pulmonary artery; RPA, right pulmonary artery; LPA, left pulmonary artery; A, aorta; SVC, superior vena cava; DA, descending aorta; RB, right main bronchus; LB, left main bronchus; E, esophagus; AZ, azygous vein.

Figure 4

Pulmonary venous anastomotic stenosis. Non-contrast CT image demonstrates a hourglass deformity of the right pulmonary vein (red arrow) in a patient presenting with pulmonary edema and arterial hypertension three months after lung transplant consistent with pulmonary venous stenosis.

Figure 5

Pulmonary thromboembolism complications post lung transplant. Coronal CT (A) and pulmonary arteriogram (B) demonstrate segmental filling defect within the left lower lobe (white arrows) in a post lung transplant patient consistent with thromboembolism.

Figure 6

Endovascular treatment of pulmonary thromboembolism in a post lung transplant patient. Axial contrast enhanced CT (A) showing a normal right pulmonary artery transplant anastomosis with acute-appearing thrombus immediately distal to the anastomosis extending into lobar branches (red arrows). Coronal CTA (B) showing a normal right pulmonary artery transplant anastomosis with acute-appearing thrombus immediately distal to the anastomosis extending into lobar branches (red arrows). Fluoroscopic spot film (C) showing an expansile filling defect in the right inferior pulmonary artery (red arrow) with distal stasis during gentle contrast injection (blue arrow). Fluoroscopic spot film (D) showing the position of a 10-cm infusion length thrombolysis catheter (red arrow) for continued thrombolysis infusion therapy. Right pulmonary angiogram (E) was obtained after 12 h of thrombolysis. Note that although there are residual filling defects, there is interval improved flow. Patient was subsequently treated with systemic anticoagulation. Ventilation and perfusion scan (F) performed 6 months after thrombolysis shows matched non-segmental defects in the right upper and lower lobes, sequelae of prior thromboembolism (orange arrows). CXR (G) at 6 months post lysis shows residual scarring in the area of prior infarcts and a chronically blunted right costophrenic sulcus (orange arrows).