Pulmonary vascular sequelae after lung transplantation occur in approximately

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1 Case Reports Pranav Loyalka, MD Cihan Cevik, MD Sriram Nathan, MD Igor D. Gregoric, MD iswajit Kar, MD mit Parulekar, MD Scott. Scheinin, MD Harish Seethamraju, MD Key words: ngioplasty, balloon/instrumentation; constriction, pathologic/ diagnosis; lung transplantation/adverse effects; postoperative complications/ etiology; pulmonary veins/ pathology/radiography; pulmonary veno-occlusive disease/diagnosis/surgery; treatment outcome; ultrasonography, interventional From: Departments of Cardiology (Drs. Cevik, Kar, Loyalka, and Nathan), Cardiothoracic Surgery (Dr. Gregoric), and Cardiopulmonary Transplantation (Dr. Scheinin), Texas Heart Institute at St. Luke s Episcopal Hospital; Department of Internal Medicine (Drs. Parulekar and Seethamraju), Section of Pulmonary, Critical Care, & Sleep Medicine, aylor College of Medicine; and Department of Cardiology (Dr. Kar), Michael E. Deakey Veterans ffairs Medical Center and aylor College of Medicine; Houston, Texas ddress for reprints: Cihan Cevik, MD, Department of Cardiology, Texas Heart Institute at St. Luke s Episcopal Hospital, 6720 ertner ve., Houston, TX ccevik@sleh.com 2012 by the Texas Heart Institute, Houston Percutaneous Stenting to Treat Pulmonary Vein Stenosis after Single-Lung Transplantation Pulmonary vein stenosis after lung transplantation is rare. Untreated, it can cause transplant failure and death. We describe the case of a 56-year-old man in whom pulmonary vein stenosis developed after single-lung transplantation. He was successfully treated with angioplasty and stent implantation guided by intravascular ultrasonography. To our knowledge, this is the first report of using this method to evaluate the pulmonary vein after lung transplantation, to confirm the diagnosis of pulmonary vein stenosis, and to guide the sizing and positioning of a stent. In lung-transplant recipients, percutaneous stent implantation may preclude reoperation and salvage the transplanted lung when used as treatment for pulmonary vein stenosis. (Tex Heart Inst J 2012;39(4):560-4) Pulmonary vascular sequelae after lung transplantation occur in approximately 1% of patients and are associated with graft failure, repeat transplantation, and a high mortality rate. 1 These sequelae usually involve the pulmonary artery and are typically treated surgically. Pulmonary vein stenosis (PVS) is rare after lung transplantation. Patients usually present with dyspnea, hemoptysis, alveolar infiltrates on chest radiography, impaired gas exchange, and oxygen desaturation. The clinical picture of PVS is similar to that of pneumonia, reperfusion injury, and transplant rejection 1 ; accordingly, the diagnosis of PVS in lung-transplant recipients can be challenging and might be overlooked. lthough reoperation is currently the preferred treatment, the best treatment option is unknown. We describe the percutaneous implantation of a stent to relieve venous obstruction in a patient after left-lung transplantation. Case Report 56-year-old man with end-stage idiopathic pulmonary fibrosis underwent orthotopic left-lung transplantation without cardiopulmonary bypass. The procedure was uneventful, and an intraoperative transesophageal echocardiogram showed normal venous flow. However, the patient s clinical condition and oxygen saturation level did not improve after the procedure. chest radiograph revealed pulmonary venous congestion, which did not resolve after therapy with intravenous diuretics (Fig. 1). Results of bronchoscopy and transbronchial biopsies excluded the possibility of acute transplant rejection or infection and showed diffuse alveolar infiltrates. Contrastenhanced computed tomography (CT) revealed significant left-lower PVS: the crosssectional area of the lower left pulmonary vein (PV) was 0.17 cm 2, whereas the areas of the upper right and lower right PVs were each 2.0 cm 2 (Fig. 2). ecause reoperation posed a high risk to the patient, percutaneous angioplasty and stent implantation were recommended. The patient provided consent and was brought to the catheterization laboratory. n 8.5F gilis NxT Steerable Introducer (St. Jude Medical, Inc.; St. Paul, Minn) was placed in the right femoral vein and advanced over the wire into the right atrium, and transseptal puncture was performed under the guidance of intracardiac echocardiography. The gilis sheath was then introduced into the left atrium, and the transseptal needle and dilator were removed in STORQ guidewire (Cordis Endovascular Systems, Inc., a Johnson & Johnson company; Miami Lakes, Fla) was advanced into the lower left PV, and a 5F multipurpose catheter was advanced over the wire into that vein. During the pullback of the multi- 560 Stenting to Treat PVS after Lung Transplantation

2 Fig. 1 Chest radiograph shows left pulmonary venous congestion after lung transplantation. purpose catheter, a transpulmonary venous gradient of 8 mmhg was recorded from the stenotic vein. When the lower left PV was re-evaluated with the use of intravascular ultrasonography (IVUS), the obstruction was confirmed; the cross-sectional area of the vein was 0.2 cm2 in the obstructed segment versus 1.7 cm2 in the poststenotic segment (Fig. 3). The stenotic segment was dilated with a 9 u 20-mm dmiral Xtreme over-the-wire balloon (Invatec Inc.; ethlehem, Pa), at nominal pressure, 3 times for 30 seconds each (Fig. 4). However, after the angioplasty, the transpulmonary venous gradient was 7 mmhg. 10 u 25-mm Express LD iliac stent (oston Scientific Corporation; Natick, Mass) was deployed into the stenotic segment at nominal pressure (Fig. 4). fter stent deployment, a pulmonary venogram revealed that the obstruction had disappeared (Fig. 5). C D Fig. 2 ) Contrast-enhanced computed tomogram shows the patient s chest. ) Significant left-lower pulmonary vein stenosis has a cross-sectional area of 0.17 cm 2. C), D) Consecutive frames show the obstructed segment longitudinally (arrows). Texas Heart Institute Journal Stenting to Treat PVS after Lung Transplantation 561

3 The transpulmonary venous gradient was 0 mmhg. The patient s oxygen saturation level improved, and his dyspnea resolved. Chest radiography showed that the left-lower-lobe infiltrate had also resolved. The patient was asymptomatic after 1 month s therapy with aspirin (325 mg) and clopidogrel (75 mg). Fig. 3 Intravascular ultrasonographic images of the left lower pulmonary vein. ) Obstruction is confirmed, with a cross-sectional area of stenosis of 0.2 cm 2. ) The poststenotic segment has a cross-sectional area of 1.7 cm 2. Fig. 4 ngiograms show ) the 9 20-mm dmiral Xtreme over-the-wire balloon used to dilate the stenotic segment, and ) the mm Express LD iliac stent that was deployed into the stenotic segment at nominal pressure. 562 Stenting to Treat PVS after Lung Transplantation

4 Fig. 5 Pulmonary venogram shows no obstruction (arrow) after stent deployment. Discussion We used IVUS to measure the gradient across the stenotic vein during the procedure and to confirm the diagnosis of PVS in our patient. To our knowledge, the use of IVUS in this situation has not been reported previously. We think that using IVUS to evaluate the PV was important, because it enabled optimal viewing of the stenotic segment and the mechanism of the obstruction, and it helped us to size and position the stent appropriately. Pulmonary vein stenosis is a well-known sequela of catheter-guided atrial fibrillation ablation procedures. lung ventilation/perfusion scan that indicates abnormal blood flow within the stenotic vessel can suggest PVS. Magnetic resonance angiography, CT, and transesophageal echocardiography are typically used to diagnose PVS. Cardiac catheterization with transseptal puncture and selective pulmonary venography are currently the gold-standard techniques for confirming a diagnosis of PVS. The diagnosis of PVS is essential and depends upon the mean visual angiographic stenosis and mean trans-stenotic gradient. In our patient, CT and IVUS yielded additional information for evaluation of the stenosis. Packer and co-authors 2 reported 80% 13% mean angiographic stenosis and a 12 5-mmHg mean trans-stenotic gradient in 23 patients with PVS. Our patient had an 80% angiographic stenosis with an 8-mmHg gradient, and CT and IVUS determined the cross-sectional area of stenosis to be 0.17 cm 2 and 0.2 cm 2, respectively. We believe that any gradient greater than 7 mmhg could be significant if the patient s clinical presentation, chest radiograph, or ventilation/perfusion scan suggests diminished blood flow within the distribution of the stenosed vein. The optimal method of treating iatrogenic PVS that results from catheter-guided atrial fibrillation ablation is controversial, although angioplasty with or without stent implantation is usually performed. These patients are usually given warfarin postprocedurally, because atrial fibrillation may recur. 3 In contrast, our patient was in sinus rhythm, and the cause of his PVS was different; therefore, we prescribed aspirin and clopidogrel instead of warfarin. The ideal antiplatelet and anticoagulative therapy for patients in whom PVS develops after lung transplantation is unclear because of the infrequency of such cases. Pulmonary vein stenosis after lung transplantation is less common than iatrogenic, ablation-related PVS. It can cause respiratory distress and render the transplanted lung unviable, resulting in death. Furthermore, reoperation to relieve the obstruction increases the patient s risk of death substantially. The treatment of PVS with percutaneous stent implantation after lung transplantation has been reported in 3 other patients. 1,4,5 In each, a bare-metal stent was used, and each procedure was uneventful, with no in-hospital death. However, because PV stenting can cause anastomotic rupture, this procedure should not be performed without standby surgical support and interventional rescue therapy, such as the deployment of covered stents. Nonetheless, percutaneous angioplasty with or without stent implantation could be a promising treatment option in these patients, and a potentially safer alternative to surgery for treating PVS after lung transplantation. The use of IVUS guidance during the procedure could also improve the patient s outcome by yielding useful information about stent size and apposition, thereby reducing the risk of restenosis and the need for reintervention. cknowledgments The authors thank Nicole Stancel, PhD, and Stephen N. Palmer, PhD, ELS, of the Texas Heart Institute at St. Luke s Episcopal Hospital, for editorial assistance. References 1. Clark SC, Levine J, Hasan, Hilton CJ, Forty J, Dark JH. Vascular complications of lung transplantation. nn Thorac Surg 1996;61(4): Packer DL, Keelan P, Munger TM, reen JF, sirvatham S, Peterson L, et al. Clinical presentation, investigation, and management of pulmonary vein stenosis complicating ablation for atrial fibrillation. Circulation 2005;111(5): Holmes DR Jr, Monahan KH, Packer D. Pulmonary vein stenosis complicating ablation for atrial fibrillation: clinical spectrum and interventional considerations. JCC Cardiovasc Interv 2009;2(4): Pazos-Lopez P, Pineiro-Portela M, ouzas-mosquera, Peteiro-Vazquez J, Vazquez-Gonzalez N, Rueda-Nunez F, et al. Texas Heart Institute Journal Stenting to Treat PVS after Lung Transplantation 563

5 Images in cardiovascular disease. Pulmonary vein stenosis after lung transplantation successfully treated with stent implantation. Circulation 2010;122(25): Zimmermann GS, Reithmann C, Strauss T, Hatz R, renner P, Uberfuhr, et al. Successful angioplasty and stent treatment of pulmonary vein stenosis after single-lung transplantation. J Heart Lung Transplant 2009;28(2): Stenting to Treat PVS after Lung Transplantation