Ann Thorac Surg 2008;86:1375-1377. doi:10.1016/j.athoracsur.2008.04.006
© 2008 The Society of Thoracic Surgeons
Case Reports
Minimally Invasive Epicardial Left Atrial Ablation and Appendectomy for Refractory Atrial Tachycardia
Jeremy R. McGarvey, MDa,
David Schwartzman, MDb,
Takeyoshi Ota, MDa,
Marco A. Zenati, MDa,*
a Division of Cardiac Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
b Atrial Arrhythmia Center, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
Accepted for publication April 3, 2008.
* Address correspondence to Dr Zenati, Cardiac Surgery, University of Pittsburgh, Suite C-700, 200 Lothrop St, Pittsburgh, PA 15213 (Email: zenatim{at}upmc.edu).
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Abstract
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Surgical removal or epicardial radiofrequency ablation of the left atrial appendage (LAA) is occasionally required when endocardial ablations fail. We report a modified minimally invasive surgical approach for elimination of recurrent atrial arrhythmias arising from the LAA, including both radiofrequency ablation and appendectomy. Ablation of the LAA base was performed using the Medtronic Cardioblate bipolar radiofrequency device (Medtronic, Minneapolis, MN), and left atrial appendectomy was then completed using the EndoGIA stapling system (US Surgical, Norwalk, CT). This procedure successfully isolated and removed the tachycardia focus, and normal sinus rhythm was restored. Elimination of LAA arrhythmias using a combination of epicardial radiofrequency ablation and appendectomy ensures electrical isolation while minimizing surgical invasiveness.
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Introduction
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The left atrial appendage (LAA) is an unusual site of origin for atrial tachycardias (AT), constituting the focus in only 3% to 7.7% [1, 2]. Percutaneous endocardial radiofrequency (RF) ablation of the LAA is generally successful at eliminating AT circuitry [3, 4]. Several series have shown that AT foci within the nontrabeculated LAA base are especially responsive to endocardial RF ablations, with the small percentage of recurrences requiring only repeat endocardial ablation for definitive cure [2, 5]. Nonetheless, epicardial foci or anatomic limitations, such as those within the trabeculated portion or apex of the LAA, remain a potential barrier and recurrence risk for percutaneous epicardial ablation of AT. We present a case of longstanding atrial tachycardia refractory to endocardial RF ablation that was cured after combined minimally invasive epicardial ablation and left atrial appendectomy.
A 46-year-old woman presented to our institution with a greater than 40 years history of supraventricular tachycardia that was highly symptomatic, despite appropriate combination antiarrhythmic pharmacotherapy. Electrophysiologic study of the arrhythmia found a tachycardia cycle length of 460 ms, and subsequent activation mapping (CARTO; Biosense-Webster, Diamond Bar, CA) localized the tachycardia to a 2 cm2 area in the superior portion of the trabeculated LAA (Fig 1). At the time of mapping, RF ablation was applied to the endocardial surface using an irrigated ablation catheter. After administration of RF energy to the site, the tachycardia ceased with subsequent restoration of normal sinus rhythm. Graded dose isoproterenol at that time failed to induce arrhythmia; however, within 24 hours postprocedurally the atrial tachycardia returned. Pharmacotherapy was reinstituted at that time; however, the patient continued to have frequent and worsening episodes of highly symptomatic AT over the course of the following weeks.
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Fig 1. Left atrial appendage (arrow) and left superior pulmonary vein (arrowhead) as viewed from intercostal access port. Site of focal atrial tachycardia.
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Given continuing AT, the patient was referred for surgical intervention. Under general endotracheal anesthesia with differential lung ventilation, two 15-mm ports were created at the fifth and seventh left intercostal spaces, respectively, for access and video-assistance to the left chest and heart. The pericardium was incised posterior to the phrenic nerve and the LAA was exposed. A Medtronic Cardioblate bipolar RF device (Cardioblate; Medtronic, Minneapolis, MN) was introduced into the left chest and positioned at the base of the LAA flush with the wall of the left atrium (Fig 2) [6]. Confirmation that the entire LAA was captured by the Cardioblate device was made with transesophogeal echocardiography. Three sequential applications of RF energy were performed at approximately 30 watts of energy each; pacing from the tip of the LAA failed to capture the ventricle at 10 mA, indicating complete electrical isolation. Electrocardiogram at that time showed physiologic pacing from the sinus node at a normal rate and rhythm. An Endo GIA stapler with reinforced Seamguard buttresses (Endo GIA, US Surgical, Norwalk, CT) was introduced through the trocar port, and the LAA was captured cleanly at the base and was stapled (Fig 3). The LAA was then removed and sent for histologic examination. Close examination of the staple line did not reveal any evidence of bleeding. The patient was extubated in the operating room and was discharged home on postoperative day 4. There was no recurrence of atrial tachycardia or symptoms for the duration of her 2-year follow-up period without medications.
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Fig 2. Capture and electrical isolation of left atrial appendage with Medtronic Cardioblate Bipolar RF device (Medtronic, Minneapolis, MN).
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Fig 3. Removal of left atrial appendage with Endo GIA 60/35 AutoSuture (Endo GIA, US Surgical, Norwalk, CT) with Gore-Tex (W. L. Gore & Assoc, Flagstaff, AZ) buttresses.
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Comment
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The AT foci originating in the LAA (although rare) are often successfully ablated and cured through a percutaneous endocardial approach. However, in even rarer instances, such cases will be refractory to endocardial RF ablation and require surgical ablation or LAA removal, or both, to cure the tachyarrhythmia. A surgical approach may be especially considered if the tachyarrhythmia focus is located in the thin-walled apex or trabeculated portion of the LAA. In such circumstances, a minimally invasive approach is preferred. Accordingly, Yamada and colleagues [7] have described a minimally invasive approach to the left atrial appendectomy for cure of an LAA tachycardia focus; however, no epicardial ablations were performed. In our case, we first delivered circumferential irrigated RF energy to the LAA base, and we subsequently confirmed isolation and elimination of the recurrent AT. The left atrial appendectomy just distal to the ablation lesion then definitively removed the LAA, which reduced the potential for recurrence and eliminated the risk of thromboembolism while ensuring adequate tissue healing. By performing epicardial ablation prior to appendectomy, additional applications of RF energy are possible in cases in which the AT focus is not initially eliminated, unlike the approach described by Yamada and colleagues [7]. Conversely, if appendectomy is first performed without resolution of the AT, subsequent epicardial RF ablations may be unfeasible or unsafe due to inadequate atrial tissue proximal to the stapled edge. As such, combination epicardial ablation, and then appendectomy seems to be a more accommodating minimally invasive option for treatment of arrhythmias arising from the LAA.
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References
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- Hachiya H, Ernst S, Ouyang F, et al. Topographic distribution of focal left atrial tachycardias defined by electrocardiographic and electrophysiological data Circ J 2005;69:205-210.[Medline]
- Wang Y-W, Li X-B, Quan X, et al. Focal atrial tachycardia originating from the left atrial appendage: electrocardiographic and electrophysiologic characterization and long-term outcomes of radiofrequency ablation J Cardiovasc Electrophysiol 2007;18:459.[Medline]
- Graffigna A, Vigana M, Pagani F, et al. Surgical treatment for ectopic atrial tachycardia Ann Thorac Surg 1992;54:338-343.[Abstract]
- Hillock RJ, Singarayar S, Kalman JM, et al. Tale of two tails: the tip of the atrial appendages is an unusual site for focal atrial tachycardia Heart Rhythm 2006;3:467-469.[Medline]
- Yamada T, Murakami Y, Yoshida Y, et al. Electrophysiologic and electrocardiographic characteristics and radiofrequency catheter ablation of focal atrial tachycardia originating from the left atrial appendage Heart Rhythm 2007;4:1284-1291.[Medline]
- Bonanomi G, Schwartzman D, Francischelli D, Hebsgaard K, Zenati MA. A new device for beating heart bipolar radiofrequency atrial ablation J Thorac Cardiovasc Surg 2003;126:1859-1866.[Abstract/Free Full Text]
- Yamada Y, Ajiro Y, Shoda M, et al. Video-assisted thoracoscopy to treat atrial tachycardia arising from left atrial appendage J Cardiovasc Electrophysiol 2006;17:895-898.[Medline]
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Abstract
Introduction
