Acquired Pulmonary Vein Stenosis: One Problem, Two Mechanisms Anna M. Booher, MD and David S. Bach, MD, Ann Arbor, Michigan
Until the last decade, acquired pulmonary vein (PV) stenosis in the adult population was a rare finding, caused by neoplasm or inflammatory conditions such as sarcoidosis or fibrosing mediastinitis. With the increased use of catheter-based ablation for the treatment of atrial fibrillation, PV stenosis is increasingly recognized as a complication of this procedure. Additionally, PV stenosis has been described as a rare complication of cardiac surgery. This report describes two cases of PV stenosis, one acquired as a result of multiple left atrial ablation procedures and the other after surgical cannulation of the right upper PV. (J Am Soc Echocardiogr 2010;23:904.e1-904.e3.) Keywords: Pulmonary vein anatomy, Cardiac surgery, Atrial fibrillation, Catheter-based ablation procedure
Until the last decade, acquired pulmonary vein (PV) stenosis in the adult population was due to rare causes such as neoplasm or to inflammatory conditions such as sarcoidosis or fibrosing mediastinitis.1 However, with the increased use of catheter-based ablation for the treatment of atrial fibrillation, PV stenosis is increasingly recognized as a complication of this procedure. Additionally, PV stenosis has been described as a rare complication of cardiac surgery. Two cases of acquired PV stenosis are presented.
CASE PRESENTATIONS Case 1 A 49 year-old man presented with a 13-year history of atrial fibrillation. Other medical history included type 2 diabetes mellitus, hypertension, obstructive sleep apnea, hyperlipidemia, and chronic back pain. After medical therapy for atrial arrhythmias was unsuccessful, the patient underwent 5 radiofrequency atrial ablation procedures over the course of 5 years; the first 4 procedures were for atrial fibrillation, and the most recent was for left atrial flutter. Prior to planned electrical cardioversion for atrial flutter, transesophageal echocardiography (TEE) was performed to exclude left atrial thrombus. Although not well seen on 2-dimensional imaging of the ostium of the left upper PV (Figure 1, Video 1), there was associated color variancing suggestive of flow acceleration on color-flow Doppler imaging (Video 2). Continuous-wave Doppler evaluation revealed a high antegrade flow velocity (maximum, 1.9 m/s) consistent with left upper PV stenosis (mean gradient, 4.8 mm Hg) (Figure 2). Retrospective review of a transthoracic echocardiogram obtained 2 weeks prior to TEE demonstrated turbulent flow in the left atrium in the apical 4-chamber view. From the Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan. Reprint requests: Anna M. Booher, MD, University of Michigan Cardiovascular Center, 1500 E Medical Center Drive, Ann Arbor, MI 48109-5853 (E-mail:
[email protected]). 0894-7317/$36.00 Copyright 2010 by the American Society of Echocardiography. doi:10.1016/j.echo.2009.12.015
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Case 2 A 62-year-old woman underwent TEE after recent aortic valve replacement. Surgery was performed for aortic regurgitation, with the implantation of a 19-mm stentless aortic bioprosthesis. There was no history of transcatheter or surgical therapy for atrial arrhythmias. Her postoperative course was complicated by renal failure requiring hemodialysis and subsequent hospitalization with diarrhea, abdominal pain, shortness of breath, and weakness. She was found to have elevated B-type natriuretic peptide, and echocardiography was performed to assess left ventricular (LV) systolic function. Transthoracic echocardiography revealed normal LV systolic function, systolic narrowing of the LV outflow tract (diameter, 15 mm), and elevated mean and peak LV outflow gradients (23 and 48 mm Hg, respectively). Because the aortic valve prosthesis was not well seen, TEE was performed to evaluate the LV outflow tract and the aortic valve prosthesis. On TEE, the LV outflow tract was narrow but unobstructed, and the aortic valve prosthesis functioned normally. However, note was made of anatomic narrowing of the ostium of the right upper PV (Figure 3, Video 3) and turbulent antegrade flow entering the left atrium from the right upper PV (Video 4). Spectral Doppler interrogation of PV flow revealed an antegrade peak velocity > 2 m/s. The operative report from the aortic valve replacement procedure was reviewed, confirming placement of a venting cannula in the right upper PV, with no other reference to direct injury to a PV or the left atrium.
DISCUSSION During the past decade, advances in electrophysiology have led to better understanding of the pathophysiology of atrial fibrillation, and electroanatomic mapping techniques have been developed that allow for catheter-based radiofrequency ablation and electrical isolation of the PV ostia for the treatment of atrial fibrillation and flutter. It is estimated that nearly 50,000 atrial fibrillation ablations procedures are now performed annually in the United States, with clinical success rates reported to be >80%.2,3 However, PV stenosis remains a potential complication of catheter ablation for atrial fibrillation, with a current reported incidence of 1% to 3%.4,5
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Figure 1 Still-frame two-dimensional image of the left atrial appendage (LAA) and left upper PV (LUPV) entering into the left atrium (LA).
Figure 2 Continuous-wave Doppler of the left upper PV with peak velocity of 1.9 m/s and mean gradient of 4.8 mm Hg. In 2003, Saad et al5 reported on 18 patients with severe PV stenosis following catheter ablation of atrial fibrillation. In that study, the median number of stenosed PVs was 2, and total occlusion of a PV was seen in 7 patients. As seen in our first case, stenosis more commonly involved a left-sided PV. The proposed explanation for this was that the ablation catheter can move more easily into a left-sided PV with respiration, and stenosis is more likely when energy is delivered within the PV rather than in the preferred ostial location. Multidetector computed tomography is considered the gold standard for PV evaluation before and after ablation.6 However, even though imaging of the inferior PVs using TEE can be difficult, TEE has been shown to be of value in diagnosing and following patients with PV stenosis. De Piccoli et al7 published a series of 96 patients undergoing atrial fibrillation ablation and found that during 1 year of follow up, PV diameter on TEE decreased by 5% and peak flow velocities increased by 32% in all patients. In those with PV stenoses $ 50% on computed tomography, flow velocities were shown to double over baseline values, and the diameter of the PV on echocardiographic imaging was significantly reduced. Others have shown that severe PV stenosis, as defined at cardiac catheterization, correlates well with a peak velocity $ 2 m/s on spectral Doppler interrogation
Figure 3 Still-frame two-dimensional image of the right upper PV (RUPV) with narrowing near the ostium (yellow arrow). Also shown is the left atrium (LA) and right pulmonary artery (RPA). of the PVs.8 Although the absolute reduction in PV diameter was not well seen on 2-dimensional images (Figure 1, Video 1) in our first case, the stenosis is readily evident on the basis of color-flow and spectral Doppler evaluation. This example underscores the importance of, and incremental diagnostic value afforded by, careful Doppler examination. PV stenosis also has been described as a rare complication of cardiac surgery. Most commonly, it is described in the pediatric literature after repair of complex congenital conditions in which the atria and PVs are directly manipulated, such as in anomalous pulmonary venous return or atrial switch operations (the Mustard procedure) in D-transposition of the great vessels.9,10 In adults who undergo cardiac surgery, PV stenosis has been reported after autotransplantation for myxoma and after inadvertent injury of the left atrium or PV.11,12 However, as a component of cardiopulmonary bypass, a left atrial vent is placed. In patients with significant aortic insufficiency, the right upper PV is a preferred site for cannula placement; when the vent is removed, the defect is sutured. In case 2, suture repair of the right upper PV cannulation site is the most plausible explanation for isolated right upper PV stenosis. To our knowledge, this is the first reported case of PV stenosis acquired by this mechanism. In conclusion, even as experience increases and interventional techniques improve, acquired PV stenosis remains a potential complication of atrial fibrillation ablation; it also is a rare complication of cardiac surgery. Symptoms can develop even in instances when stenosis is not severe, and lesions can progress over time. Echocardiography has an important role in the diagnosis and follow-up of patients with acquired PV stenosis. Of note, both cases presented here were noted as incidental findings on TEE performed for another indication. Close attention should be paid to pulmonary symptoms in patients with recent ablation or open surgical procedures to facilitate the diagnosis and management of this condition.
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3. Oral H, Knight BP, Ozaydin M, Tada H, Chugh A, Hassan S, et al. Clinical significance of early recurrences of atrial fibrillation after pulmonary vein isolation. J Am Coll Cardiol 2002;40:100-4. 4. Holmes DR Jr, Monahan KH, Packer D. Pulmonary vein stenosis complicating ablation for atrial fibrillation: clinical spectrum and interventional considerations. JACC Cardiovasc Interv 2009;2:267-76. 5. Saad EB, Marrouche NF, Saad CP, Ha E, Bash D, White RD, et al. Pulmonary vein stenosis after catheter ablation of atrial fibrillation: emergence of a new clinical syndrome. Ann Intern Med 2003;138:634-8. 6. Scharf C, Sneider M, Case I, Chugh A, Lai SW, Pelosi F Jr, et al. Anatomy of the pulmonary veins in patients with atrial fibrillation and effects of segmental ostial ablation analyzed by computed tomography. J Cardiovasc Electrophysiol 2003;14:150-5. 7. De Piccoli B, Rossillo A, Zanella C, Bonso A, Themistoclakis S, Corrado A, et al. Role of transoesophageal echocardiography in evaluating the effect of catheter ablation of atrial fibrillation on anatomy and function of the pulmonary veins. Europace 2008;10:1079-84.
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8. Vick GW III, Murphy DJ Jr, Ludomirsky A, Morrow WR, Morriss MJ, Danford DA, et al. Pulmonary venous and systemic ventricular inflow obstruction in patients with congenital heart disease: detection by combined two-dimensional and Doppler echocardiography. J Am Coll Cardiol 1987; 9:580-7. 9. Devaney EJ, Ohye RG, Bove EL. Pulmonary vein stenosis following repair of total anomalous pulmonary venous connection. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2006;51-5. 10. Ussia G, Marasini M, Zannini L, Pongiglione G. Acquired pulmonary vein obstruction after open-heart surgery. Eur J Cardiothorac Surg 2002;22: 465-7. 11. Rosetti M, Tighe DA, Chandok D, Gammie JS, Griffith BP, Folland ED. An unusual cause of pulmonary vein stenosis: a case report and review of the literature. Echocardiography 2006;23:685-8. 12. Anh D, Dudar B, Ananthasubramaniam K. Acquired isolated left pulmonary vein stenosis: a complication of bronchogenic cyst removal diagnosed by transesophageal echocardiography. Echocardiography 2006;23:73-4.