CASE REPORT – ADULT CARDIAC
Interactive CardioVascular and Thoracic Surgery 21 (2015) 803–804 doi:10.1093/icvts/ivv256 Advance Access publication 22 September 2015
Cite this article as: Ventosa-Fernandez G, Quintana E, Castellá M, Pereda D. Exclusion of the left atrial appendage with the TigerPaw II system: a word of caution. Interact CardioVasc Thorac Surg 2015;21:803–4.
Exclusion of the left atrial appendage with the TigerPaw II system: a word of caution Guillermo Ventosa-Fernandez, Eduard Quintana, Manuel Castellá and Daniel Pereda* Department of Cardiovascular Surgery, Hospital Clínic of Barcelona, University of Barcelona, Barcelona, Spain * Corresponding author. Department of Cardiovascular Surgery, Hospital Clínic of Barcelona, 170th Villarroel St, 08036 Barcelona, Spain. Tel: +34-932275515; fax: +34-922275749; e-mail: [email protected]
(D. Pereda). Received 16 June 2015; received in revised form 13 August 2015; accepted 17 August 2015
Abstract Exclusion of the left atrial appendage (LAA) may significantly reduce the incidence of stroke associated with atrial fibrillation (AF), since this is the main thrombus source. LAA closure is becoming a therapeutic target for preventing AF-related stroke, attracting much interest in recent years. Different devices are available to provide LAA exclusion during cardiac surgery. We describe herein our experience with the recently introduced TigerPaw II system for LAA exclusion, and report a high prevalence of device malfunction. Design improvements may address these issues and increase safety for new technological devices designed for surgical LAA closure. Keywords: Atrial fibrillation • Left atrial appendage • Surgical occlusion • Stroke
Atrial fibrillation (AF) affects up to 1.3% of the general population, with a yearly risk of stroke in non-rheumatic AF of 5%. Loss of contractile function in AF and blood stasis on the left atrial appendage (LAA) represents the main source of thromboembolism, with 90% of thromboembolisms originating in the LAA . Oral anticoagulants have been used for reducing stroke risk in AF but patients are not always in therapeutic range and they may discontinue treatment or present contraindications. On the other hand, lifelong treatment carries a significant cumulative risk of bleeding and the need for frequent monitoring. New anticoagulants do not overcome all these downsides and are not indicated for valvular AF , the commonest among cardiac surgery patients. Exclusion or amputation of the LAA may significantly reduce the incidence of stroke , attracting much interest in recent years from both the interventional  and surgical perspectives and with different manufactured devices available to simplify procedures. TigerPaw II system is designed for open chest LAA closure with an implantable fastener of titanium connectors that staples the LAA tissue, embedded in two rims of silicone that adapts to the LAA morphology and seals the puncture sites . Recently, the U.S. Food and Drug Administration made a Class I recall due to safety concerns and the device is not currently on the market.
CLINICAL SUMMARY From November 2014, we started using the TigerPaw II device (Maquet, Inc., Rastatt, Germany) approved for LAA exclusion at
our institution. Until March 2015, 11 patients with preoperative AF scheduled for elective non-endoscopic cardiac procedures received concomitant LAA exclusion by means of the TigerPaw II system. Device-related problems were observed in 5 of 11 procedures (45%) performed by three different surgeons and occurred throughout the series, including the last 2 cases and after a number of uneventful cases. Incomplete closure of the rims either proximally or distally was the most frequently observed malfunction. In 2 cases, the incompletely closed devices could be removed without tissue damage and additional TigerPaw II clips were deployed uneventfully. In 3 cases, a tear at the base of the LAA was accompanied by severe bleeding (Figs 1 and 2). This was managed by device removal in all the 3 cases, along with LAA amputation and external closure in 2 patients and by internal suture of the LAA in the remaining. In all patients who did not present any complication or device dysfunction, intraoperative transoesophageal echocardiography showed effective LAA closure. There were no further complications postoperatively.
DISCUSSION Despite a lack of a high level of evidence supporting surgical LAA exclusion, current guidelines advise concomitant surgical LAA excision in patients with AF . Surgical LAA exclusion may become an effective and cost-saving adjuvant to oral anticoagulation (or serve as an alternative in those with contraindications), providing lifelong protection against cardioembolic stroke.
© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
G. Ventosa-Fernandez et al. / Interactive CardioVascular and Thoracic Surgery
Figure 1: White arrow shows incomplete device closure with LAA tear and bleeding. Black arrow shows the torn LAA. LAA: left atrial appendage.
Different devices are available to provide LAA exclusion during cardiac surgery, potentially overcoming reported unreliability of internal closure  and long-term infectious and embolic concerns with endovascular devices. Specifically-designed devices for this purpose are an interesting strategy that may reduce complications, achieve high and reproducible rates of complete LAA exclusion and simplify the procedure, particularly with minimally invasive approaches. We describe herein our experience with the TigerPaw II system for LAA exclusion and report a high prevalence of device malfunction and worrisome complications, from unreliable LAA sealing to some cases of severe LAA tearing and bleeding. We can speculate on potential causes of failure, like the fixed pin length that sometimes does not perfectly accommodate the width of the LAA wall, the tension transmitted to tissues by the deployment system and the absence of a safety mechanism allowing reopening and repositioning before release. Design improvements may address these issues and increase safety but, in its current available form, we consider the device unreliable and potentially dangerous. Recently, the FDA has initiated a Class I recall of this device and it is currently not commercially available due to concerns regarding safety.
Funding This research was conducted with departamental resources only. Conflict of interest: none declared.
Figure 2: Same case presented in Fig. 1. White arrow shows the proximal, closed portion of the system. Black arrows show the incompletely sealed portion of the device. Red arrow shows the tear at the base of the excised LAA. LAA: left atrial appendage.
 García-Fernández MA, Pérez-David E, Quiles J, Peralta J, García-Rojas I, Bermejo J et al. Role of left atrial appendage obliteration in stroke reduction in patients with mitral valve prosthesis: a transesophageal echocardiographic study. J Am Coll Cardiol 2003;42:1253–8.  January CT, Wann LS, Alpert JS, Calkins H, Cigarroa JE, Cleveland JC Jr et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation. Circulation 2014;130:2071–104.  Reddy VY, Sievert H, Halperin J, Doshi SK, Buchbinder M, Neuzil P et al. Percutaneous left atrial appendage closure vs warfarin for atrial fibrillation: a randomized clinical trial. JAMA 2014;312:1988–98.  Slater AD, Tatooles AJ, Coffey A, Pappas PP, Bresticker M, Greason K et al. Prospective clinical study of a novel left atrial appendage occlusion device. Ann Thorac Surg 2012;93:2035–40.  Kanderian AS, Gillinov AM, Pettersson GB, Blackstone E, Klein AL. Success of surgical left atrial appendage closure assessment by transesophageal echocardiography. J Am Coll Cardiol 2008;52:924–9.