internal carotid artery ( ica ) dissections may occur spontaneously or following trauma , whereas extracranial carotid artery dissections are rare conditions that account for a significant proportion of ischemic strokes in young adults ( 1 ) . on the other hand , iatrogenic dissection is a kind of traumatic dissection that may occur as a complication of neurointerventional procedures ( 2 - 4 ) . the interventionalist has to decide whether to continue with the intracranial procedure or manage the dissection by either using antithrombotics or endovascular management during or after the intervention ( 5 ) . current paper reports a dissection of the extracranial segment of the ica in a stroke case which occurred as a result of repetitive movement of the balloon guiding catheter during stent - assisted thrombectomy ( sat ) that progressed to late occlusion days after the dissection . a 66-year - old woman was brought to the emergency department with persistent symptoms of right - sided hemiparesis and aphasia . she had the same complaints twice within six hours , but not lasting more than five minutes . she was examined by cranial magnetic resonance imaging ( mri ) , including magnetic resonance angiography ( mra ) , axial fluid attenuated inversion recovery ( flair ) images , susceptibility weighted images ( swi ) , and diffusion weighted images ( dwi ) ; these revealed a patchy , restricted diffusion in the left hippocampus and left occipital lobe . mra showed a thrombus occluding the ophthalmic segment of the ica extending to the supraclinoid segment ( figure 1 a ) . under treatment with heparin , it showed a new diffusion restriction in the territory of the middle cerebral artery ( mca ) with total occlusion of the left mca in m1 segment . there was only restriction on dwi without any signal change on flair sequences , which were compatible with hyperacute ischemia . as the stroke symptoms were within the first six hours , without established findings of infarction on mri , she was admitted for emergent sat , which has to be performed within the critical time window in the anterior circulation of six hours for intraarterial thrombolysis and eight hours for sat . under general anesthesia , an 8f balloon guiding catheter ( corail , balt , france ) was placed at the distal part of the left ica cervical segment in order to decrease the migration of the dislodged thrombus . the occlusion site was reached with transend 14 microwire ( stryker , usa ) and rebar 2.8 mm microcatheter ( covidien , usa ) and sat was performed with 5  30 mm solitaire ( covidien , usa ) stent three times ( figure 1 b ) . focal dissection of the ica at the distal cervical segment was noticed due to the repeated to and fro movement of the inflated balloon guiding catheter during the thrombectomy procedure , although the balloon was inflated and deflated during every sat pass . for anterior circulation strokes , while withdrawing the thrombus with the aid of the thrombectomy stent , there is a risk of dislodgment of the thrombus to distal branches of the mca and anterior cerebral artery ( aca ) . in order to decrease the risk of dislodgment , it is preferred to use a balloon guiding catheter to stop the flow and perform suction during withdrawal of the thrombus . the dissection did not cause any flow disturbance or progression at the left ica and the mca was recanalized after the fourth sat ( figure 1 c ) . the patient had no additional symptoms and her clinical status progressively improved over the following days . the patient was placed on a low dose of heparin during the follow - up period , which is the accepted follow - up guideline for dissections and she was coumadinized on the seventh day . the etiology of the stroke was accepted as being of cardioembolic origin because she was diagnosed as having atrial fibrillation on electrocardiography . there was no pathological signal on mri after the stroke treatment and her 24-hour control computed tomography . on the seventh day before discharge , the left ica lumen was almost occluded on a color doppler ultrasonography scan . although the patient was on coumadin treatment , the dissection flap at the cervical ica segment had progressed to the ophthalmic segment distally , downwards to the ica orifice , and was occluded on mra . the patient was asymptomatic at discharge and a follow - up scan six to eight weeks later was planned . she did not have any complaints during the eight weeks , but the dissected ica segment did not recanalize and the occlusion extended from the ica orifice to the ophthalmic segment of the ica based on mra , despite being on coumadin therapy ( figure 2 ) . iatrogenic dissection as a complication of neurointerventional procedures usually occurs when there is a tear in the intima of the arterial wall leading to intrusion of blood within the layers and formation of a false lumen . a false lumen often causes flow limitation to a variable extent ( 1 , 5 , 6 ) . reported an incidence of 0.25% and akins et al . reported cervical carotid artery dissection in five cases of 144 ( 3.5% ) during endovascular treatment for acute stroke ( 7 , 8) . none of these studies reported the complications in relation with the catheter type except for akins et al . they reported the incidence of dissection to be 4.5 % using the solitaire device which was the thrombectomy stent used in the present case ( 8) . as mentioned before , there are very few cases in the literature , because some operators may consider small and asymptomatic dissections to be  technical events  , rather than complications , and therefore not report them ( 5 ) . although it has not been statistically proven that iatrogenic dissections occur more frequently during neurointerventional procedures than during diagnostic cerebral angiography , the risk of iatrogenic dissection may be slightly elevated in neurointerventional procedures due to an increased number of vascular runs , catheter exchanges , and distal placement of catheters ( 5 ) . argued that most cases had multiple manipulations , ranging from one to six , in the dissected vessels ( 7 ) . in this study , it was noted that the dissection of the extracranial ica after three sat passes during the stroke treatment was due to the repetitive movement of the balloon guiding catheter , which was not identified in a search of literature . although there is no specific therapy for dissection of the ica , the most common application for symptomatic spontaneous or traumatic dissections is intravenous administration of heparin . hart and easton recommend a follow - up protocol which consists of using heparin for seven days and coumadin for three months . if there is no sign of ischemia , aspirin may be recommended for dissections ( 5 , 9 ) . there are reports that suggest stenting as an optional treatment , whereas paramasivam et al . stented cases with luminal stenosis of over 70% and poor intracranial circulation ( 7 ) . stroke resulting from dissection usually occurs within the first week , however it may occur after up to a one month period . for this reason , it is suggested to administer anticoagulant therapy for at least one month ( 10 ) . in this case , the intervention was continued without treating the proximal dissection as there was no progression of the dissection to cause any flow disturbance or poor intracranial circulation . a dissection of the ica with a balloon guiding catheter and its progression to the proximal segment of the vessel is a rare condition . although the dissection is not usually progressive and does not usually cause stenosis , silent occlusion may be the outcome in the dissected segment . for this reason , anticoagulant therapy and follow - up imaging are necessary for nonprogressive iatrogenic dissections following neurointerventional procedures .
dissection of the internal carotid artery ( ica ) is a rare condition that accounts for a significant proportion of ischemic strokes in young adults . 
 iatrogenic dissection as a complication of neurointerventional procedures is a traumatic dissection which has been reported relatively rare in the literature . in this report , a case of dissection of the ica is reported that was caused by repetitive movement of the balloon guiding catheter during stent - assisted thrombectomy ( sat ) , resulting in occlusion of the ica .