Successful Covered Stent Treatment and Long-term Follow up of Multiple Pulmonary Vein Stenoses Guided by Rotational Angiography with 3D Reconstruction

1 Cardiac Arrhythmia Service, Steward St Elizabeth’s Medical Center of Boston, Tufts University School of Medicine, Boston, MA

2 Vascular Medicine & Interventional PV Lab, Vascular & Endovascular Medicine Fellowship Program, The Miriam and Rhode Island Hospitals, Providence, RI

3 The Warren Alpert School of Medicine of Brown University, Providence, RI

4 Eastern Maine Medical Center Electrophysiology Laboratory, Bangor, ME

5 Steward St Elizabeth’s Medical Center of Boston, MA

The authors report no conflicts of interest for the published content.

Manuscript received July 31, 2013, Final version accepted September 15, 2013.

Address correspondence to: Michael V. Orlov, MD, PhD, 736 Cambridge St, Boston, MA 02135. E-mail: michael.orlov@tufts.edu

Introduction

This 45-year-old Caucasian male with a history of highly symptomatic paroxysmal AF underwent radiofrequency catheter PV isolation procedures on two occasions at two different outside institutions. He developed dyspnea on minimal exertion, decreased exercise tolerance, and hemoptysis soon after the second PV isolation. Multislice computed tomography (CT) and cardiac magnetic resonance imaging (MRI) revealed subtotal thrombotic occlusion of the left superior PV (LSPV) and significant stenoses of the left inferior PV (LIPV) and the right superior PV (RSPV). However, the extent and severity of the stenoses remained controversial despite several opinions by experienced radiologists. The patient was thus referred for further evaluation.

Figure 1: Pre-procedural pulmonary vein (PV) stenoses visualization using several imaging modalities. (a) The posterior view on three-dimensional (3D) left atrium (LA) shell (red) produced by rotational angiography with 3D reconstruction (3DATG). Right superior PV (RSPV) stenosis (white arrow) is clearly seen at its junction with the LA. (b) Two-dimensional slice of the LA in the anterior–posterior view from 3DATG. The virtual computed tomography (CT) slice demonstrates coronal plane through the posterior part of the left atrium and RSPV–LA junction. The diameter of the stenosed segment of RSPV is measured at 4.17 mm. (c) Standard CT slice in the axial plane. Aortic root (Ao), right ventricular outflow tract (RVOT), right atrium (RA) and left atrium (LA), and LA appendage (LAA) are shown. Black arrow points to the proximal occlusion of left superior pulmonary vein. (d) Direct left inferior PV (LIPV) angiography shows its stenosis due to septation (white arrow) 2–3 cm from the ostium. Transseptal sheath (black arrow) and a guidewire in the LIPV (black arrowheads) are also shown. Ao: aortic root; RVOT: right ventricular outflow tract; RA: right atrium; LA: left atrium, LAA: left atrial appendage.

The LSPV could not be accessed due to its total occlusion. Immediately post procedure, the PCWP/LA gradient disappeared and cardiac output increased from 3.1 l/min to 4.1 l/min ( Table 1 ). Mild pulmonary arterial hypertension persisted (of note, the patient was previously diagnosed with obstructive sleep apnea).

Figure 3: Thirty-month follow up results. (a) Chest X-ray in the anterior–posterior view shows widely patent stents in right superior pulmonary vein (RSPV) (white arrow) and left inferior pulmonary vein (LIPV) (white arrowhead). (b) Three-dimensional left atrium (LA) shell by rotational angiography with three-dimensional reconstruction (3DATG) in a posterior-anterior view illustrating wide patency of RSPV (white arrow) and LIPV (white arrowhead). Black arrow points to the presumed ostium of the chronically occluded left superior pulmonary vein. LA appendage is shown in green.

Discussion

We report the first case of PTFE stent implantation guided by 3DATG to treat post-ablation PV stenoses. 3DATG was utilized to define the PV ostium, its antral portion, and to avoid stent protrusion into the LA body. The procedure was successful despite some technical challenges. During the 2-year follow-up period the patient has sustained dramatic clinical improvement. Repeat 3DATG at 13 and 30 months demonstrated widely patent stents.

Confirming the clinical diagnosis of PV stenosis with hemodynamic values can be challenging. In the Mayo Clinic series, the stenotic orifice diameter was 3±2 mm and the stenosis was deemed severe with a trans-stenotic gradient of 10–12 mmHg. 2 On the other hand, Di Biase et al. 11 have shown that even total PV occlusion can be asymptomatic if there is no concomitant stenosis of the other ipsilateral PV. However, intervention should not be deferred for less than severe stenosis if the cumulative stenotic index is more than 75%. In our case, the stenotic segment diameters were not very narrow: 5.8 mm in the LIPV and 4.17 mm in the RSPV. There was a minimal resting PV/LA gradient suggesting non-critical obstruction. Limited handgrip exercise increased the gradient to only 4 mmHg. We suspected that the gradient would have been significantly higher with real exercise. Given the fact that the LSPV was occluded, the LIPV was the only drainage for the left lung, and with intraoperative multimodality imaging, we concluded that the patient had a severe PV stenosis necessitating intervention. A significant drop in the PCWP/LA gradient, coupled with dramatic clinical improvement, confirmed our suspicion that the severity of PV stenosis was initially underestimated by baseline hemodynamic and pre-procedural anatomical measurements. Excellent clinical results despite the occluded LSPV can be probably explained by the now widely patent LIPV draining blood from the entire left lung.

PV stenting may be technically challenging. An intimal flap with transient neurologic deficit, PV tear resulting in tamponade, hemoptysis and PV dissection have been reported. 4,9 We encountered an incomplete stent dilatation causing its dislodgement on the guiding catheter. Fortunately, the stent was successfully repositioned using a partially inflated balloon and apposed satisfactorily, as confirmed by IVUS. Multimodality imaging was helpful to resolve this complex issue. Loss of access and subsequent rewiring of the vein through a partially expanded stent to the distal PV proved to be challenging and prolonged the procedure. Therefore, maintaining stable access to the distal PV throughout the procedure is of paramount importance.

Conclusion

Multiple stenoses of PVs after AF ablation can be successfully treated with PTFE-covered stents that maintain their patency over an extended follow-up (>30 months). 3DATG is an important part of a complex imaging strategy to guide the assessment of such patients and direct their intra- and postoperative management.

References

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