a 57yearold woman who had initially been implanted with a double chamber pacemaker for complete atrioventricular block was upgraded to crtp at another center after a year due to left ventricular dysfunction and dyspnea .
she was referred to us 3 months after the upgrade due to wound infection by pseudomonas sp caused by gossybypoma ( retained compress ) .
preoperative transthoracic ( tte ) and transesophageal ( toe ) echocardiography did not reveal any signs of endocarditis , and the patient was afebrile with negative blood cultures . a patent foramen ovale ( pfo ) with a small left to right shunt
traction with locking stylets allowed complete extraction of the activefixation right atrial and right ventricular leads , and the coronary sinus lead was explanted by simple traction .
the following morning she developed sudden dysarthria and left facial palsy , and emergent cerebral angiography revealed an occlusion of the right frontal branch of the middle cerebral artery ( fig .
mechanical thrombectomy with a solitaire fr revascularization device ( covidien , plymouth , mn , usa ) retrieved a thrombus attached to dense fibrinous tissue ( fig .
normal vessel flow was recovered ( fig . 2c and d ) , and neurological recovery was complete within 60 min of symptom onset .
oral antibiotics were continued for a further 2 weeks , and followup at 6 months was uneventful .
transesophageal echocardiography of the bicaval view in 2 dimensions ( a ) and using color doppler ( b ) , showing a mobile interatrial septum ( asterisk ) with a patent foramen ovale ( solid arrow ) .
( a and b ) occlusion of frontal branch of right middle cerebral artery ( arrow ) with hypoperfusion of a large territory ( asterisk ) .
( c and d ) restored flow after mechanical thrombectomy . ( a ) the solitaire 
 fr revascularization device ( covidien ) used for mechanical thrombectomy .
herein , we describe the case of a patient suffering acute ischemic stroke due to paradoxical embolization of dense fibrous material through a pfo following transvenous lead extraction ( tle ) .
endocardial pacemaker leads cause fibrin deposits on their surface which may form sheaths in over 85% of patients 1 or adhere with the vessel walls , tricuspid valves , and endocardium .
thrombi can be detected on the leads in around 30% of patients by toe and intracardiac ultrasound 2 , 3 , and findings of asymptomatic pulmonary emboli in up to 15% of patients as well as increased pulmonary pressure point toward a high rate of subclinical embolism in patients with cardiovascular implantable electronic devices ( cieds ) 1 , 3 , 4 .
one particular concern is the risk of systemic thromboembolism in patients with intracardiac shunts and cieds ; in all shunts other than pfos , the risk of systemic thromboembolism is doubled 5 and such conditions are at present considered a contraindication for endocardial lead placement 6 . in the case of pfos , the risk is less well documented , but retrospective data points toward a hazard ratio of > 3 for stroke 7 , although study bias may have exaggerated this figure .
tle is a valuable technique for management of device infection and lead failure , and its safety has improved thanks to technological advances and increasing experience .
preliminary data from the electra registry 8 , the only prospective european registry of tle , show a relatively low rate of major complications ( 2.53.9% depending on the procedural volume of centers ) .
one complication of particular concern when extracting leads is the risk of systemic embolism . indeed , residual fibrous deposits persisting after tle have been described 9 , sometimes large enough as to be described as 
our case illustrates that these residual deposits may not always be visible with toe , probably because they may be confined to the vessels ( e.g. , innominate or subclavian vein ) but may embolize later .
although the rate of stroke seems to be low ( 0.1% ) during tle , our case highlights the potentially dramatic consequences of systemic embolization , even in the absence of visible vegetations on the leads .
moreover , current guidelines offer no clear recommendations to help lower the risk of embolization during tle 10 .
routine anticoagulation , used by some centers mainly to lower the rate of venous occlusion , is probably of little use due to the fibrinous nature of the tissue .
the use of distal embolization protection devices during tle in patients with vegetations has been reported in several cases , whether in the pulmonary 11 or systemic circulation 12 .
however , the efficacy of these devices seems limited by the risk of delayed embolism as demonstrated in our case , and because residual dense fibrinous tissue probably persists for several days or weeks .
based on our case and these considerations , we believe paradoxical embolism causing stroke is a real concern in patients with pfos undergoing tle . although its incidence seems to be low , the consequences can be catastrophic and the costs linked with the morbidity of stroke are important .
although this may raise the concern of additional cost , most patients undergoing tle have a preoperative echocardiographic examination , either tte or toe , in order to evaluate preoperative tricuspid valve regurgitation or presence of vegetations .
the additional cost and time linked to evaluate for a pfo is negligible . in case of pfos with large shunts
, we suggest considering percutaneous pfoclosure before extraction in noninfected patients or surgical extraction and pfoclosure in patients with endocarditis . in cases with small pfos
, we recommend strict avoidance of maneuvres increasing righttoleft shunting ( e.g. , coughing , valsalva ) and 2448 h neurological surveillance .
the effectiveness of mechanical thrombectomy in cases of embolization after lead extraction is also highlighted in this case . because of the dense fibrous nature of embolus ( or in cases where the embolus is of foreign body material ) , pharmacological thrombolysis is likely to be ineffective , as well as increasing the bleeding risk considerably in the postoperative period .
therefore , we strongly suggest performing tle in centers with neuroradiological standby , as rapid action may prevent irreversible sequellae .
 key clinical messagesystemic embolization is a dreaded complication of transvenous lead extraction ( tle ) , even without visible vegetations . 
 preoperative patent foramen ovale evaluation is important , justifying neurological surveillance or consideration of surgical extraction in selected cases . in case of stroke after tle , 
 mechanical thrombectomy is a successful therapy , and should be readily available . 
Case Report
Case Discussion
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