Endovascular Interventions || Carotid Artery Stenting: Complication Management

129R.S. Dieter et al. (eds.), Endovascular Interventions, DOI 10.1007/978-1-4614-7312-1_8, © Springer Science+Business Media New York 2014

Carotid artery stenting (CAS) is an alternative revasculariza-tion procedure to carotid endarterectomy (CEA) for stroke prevention in selected patients. CAS is particularly attractive for patients who are at increased risk of complications with surgery, reducing the rate of myocardial infarction [ 1 ] . Yet CAS is not without its own potential for complications. The endovascular specialist who performs CAS must be expert in identifying and treating these complications. The techniques of performing CAS are discussed in another chapter and will not be reviewed again here.

Carotid Artery Stenting: Complication Management

John P. Reilly and Christopher J. White

8

J. P. Reilly , MD (*) Department of Cardiology , Ochsner Medical Center, John Ochsner Heart and Vascular Institute , 1514 Jefferson Highway , New Orleans , LA , USA

C. J. White , MD Department of Cardiology , Ochsner Health System , New Orleans , LA , USA

Contents

Slow Flow After Carotid Stenting ............................................... 130

Intracranial Hemorrhage ............................................................. 137

Summary ........................................................................................ 137

Reference........................................................................................ 137

130 J.P. Reilly and C.J. White

Case

The patient is a 78-year-old woman who presents to the of fi ce for consultation. Two weeks ago she was evaluated in the emergency department for a 15-min episode of expres-sive aphasia. She was diagnosed with a transient ischemic attack (TIA). She has hypertension, diabetes, and a history of tobacco use. Her left ventricular ejection fraction is 35 % due to an idiopathic non-ischemic cardiomyopathy and has New York Heart Association class II dyspnea on exertion. Carotid ultrasound performed last week revealed greater than 80 % stenosis of the left internal carotid artery (LICA). It is determined that she is not a surgical candidate for CEA due to her age and history of congestive heart failure. She is brought to the catheterization laboratory where angiogra-phy con fi rms a severe stenosis (Fig. 8.1 ). She underwent carotid artery stenting with distal embolic protection using a Filter Wire EZ (Boston Scienti fi c, Natick, MA) and an 8.0 × 29 mm Wallstent (Boston Scienti fi c, Natick, MA). After deployment of the stent, angiography demonstrates slow fl ow in the LICA, with normal rate of fl ow in the external carotid artery (Fig. 8.2 ). Resolution of Slow Flow: Procedure 1. As with all endovascular intervention, the operator

must maintain wire position in the vessel until completion of the intervention. This principle is par-ticularly important when a complication is identi fi ed.

2. Next the interventionalist must exclude the presence of an obstructive lesion that is restricting fl ow producing the slow fl ow present on the angiogram.

3. Fluoroscopy and angiography of the deployed stent to assure that the stent is fully expanded and that there is no signi fi cant recoil.

4. This angiogram is also examined to exclude the presence of dissection in the vessel. The edges of the stent as well as the location where the distal embolic protection device (EPD) was deployed must be examined for dissection.

5. An injection of 200 mcg of nitroglycerin may be made to treat spasm potentially due to the EPD. Extreme care must be taken to eliminate the possibility of

Fig. 8.1 Digital subtraction angiogram demonstrating a high-grade stenosis of the left internal carotid artery

Fig. 8.2 Angiogram after deployment of a stent in the carotid bifurcation. Near top of image the embolic protection device is seen. The complete fi lling of the external carotid and minimal fi lling of the internal carotid artery demonstrates the relative slow fl ow into the internal carotid artery

Slow Flow After Carotid Stenting

1318 Carotid Artery Stenting: Complication Management

injecting air bubbles into the cerebral circulation, which become obstructive emboli in these vessels. When connecting the syringe with nitroglycerin to the manifold, allow the pressure in the sheath system to expel all air out through the stopcock. The syringe is then connected to the manifold identifying fl uid-to- fl uid contact to exclude air. The interventionalist is reminded that a loose tuohy borst will introduce air into the system if vigorously aspirated in an effort to speed the process.

6. After fl ushing the nitroglycerin into the vessel, a follow-up angiogram is performed to check for resolution of the slow fl ow.

This Case After administration of 200 mcg of nitroglycerin, follow-up angiography demonstrated brisk fl ow in the LICA, at the same rate as the ECA (Fig. 8.3 ). A second angiographic run demonstrated residual spasm at the level of the angle of the jaw, the position of the EPD (Fig. 8.4 ). It is likely that the EPD was the cause for the spasm that resulted in slow fl ow.

Fig. 8.3 Digital subtraction angiogram after the administration of intra-arterial nitroglycerin and resolution of vasospasm. Equal fi lling of the internal and external carotid arteries demonstrates res-olution of slow fl ow

Fig. 8.4 Digital subtraction angiogram demonstrating residual vasospasm of the internal carotid artery at the level of the embolic protection device


Case

The patient is a 68-year-old man with a history of hyper-tension, diabetes, and coronary artery disease. He has pre-vious history of coronary artery bypass graft surgery, percutaneous coronary intervention, renal artery stenting, and lower extremity angioplasty. He presented to the emer-gency department with a 30-min episode of expressive aphasia. His primary care physician ordered a carotid ultrasound that demonstrated greater than 80 % stenosis of the left internal carotid artery (LICA). He was brought to the catheterization laboratory for angiography to con fi rm the stenosis and perform CAS. Angiography con fi rmed a severe stenosis of the LICA (Fig. 8.5 ). The patient under-went stenting using distal embolic protection with a 5.5 mm Accunet fi lter device and deployment of an 8.0 × 30 mm Acculink stent. After deployment of the stent, a 5.0 × 20 mm coronary balloon was used to postdilate the stent. Angiography revealed slow fl ow in the LICA, with normal fl ow in the external carotid artery (Fig. 8.6 ). Resolution of Slow Flow: Procedure The above six steps are followed for this case of slow fl ow after carotid artery stenting. If the administration of nitroglycerin does not resolve the slow fl ow, then exces-sive debris in the EPD may be the etiology of slow fl ow.

7. A passive aspiration catheter should be placed on the 0.014″ wire of the EPD. The Pronto extraction cath-eter (Vascular Solutions, Minneapolis, MN), the Export aspiration catheter (Medtronic Vascular, Santa Rosa, CA), and Diver aspiration catheter (formerly Invatec, Purchased by Medtronic) may all be used for this purpose.

8. The aspiration device is advanced to the stent and aspiration initiated. The entire column of blood from the stent to the EPD should be aspirated.

9. The second syringe of blood should be aspirated focused near the EPD to ensure that the debris cap-tured in the EPD is evacuated.

10. An angiogram should be performed to assess the fl ow rate. If fl ow in the ICA and ECA are equal, then aspi-ration has been successful.

11. The distal EPD all have an anchor point to which the fi lter is tethered 10–15 mm proximal to the most proximal part of the EPD. The EPD itself may be

Fig. 8.5 Digital subtraction angiogram of the left internal carotid artery demonstrating a high-grade stenosis above the bifurcation

Fig. 8.6 Angiogram after deployment of a stent in the carotid bifurcation. The complete fi lling of the external carotid and minimal fi lling of the internal carotid artery demonstrates the relative slow fl ow into the internal carotid artery


20–30 mm in length. Therefore, the aspiration cathe-ter is a minimum of 30 mm from the most distal por-tion of the EPD, challenging the ability to evacuate the device completely.

12. If slow fl ow persists, a workhorse 0.014″ coronary wire should be advanced to the ICA and carefully steered into the distal tip of the EPD. Care must be taken not to jostle the position of the EPD, once it loses contact with the vessel wall, debris may embo-lize out of the EPD.

13. The aspiration catheter then may be advanced on this second wire, which will allow it to be brought closer to the distal tip of the EPD.

14. Aspirate the debris from the EPD. 15. Perform angiography to assess if this aspiration has

resolved the slow fl ow. This Case After deployment of the Acculink stent, with slow fl ow on angiography, the patient developed right-sided weak-ness and expressive aphasia. An Export catheter was advanced over the EPD wire and passive aspiration was performed. Follow-up angiography revealed normal fl ow in both the internal and external carotids (Fig. 8.7 ). The expressive aphasia resolved and there was immediate improvement in the right-sided weakness. The hemipare-sis was completely resolved at 30-day follow-up.

After CAS, patients may develop neurologic symp-toms with stenosis or occlusion evident on intracerebral angiography (Fig. 8.8 ). In cases with acute onset of neu-rologic symptoms appropriate for the vascular distribu-tion that is compromised on the angiogram, intervention of the intracerebral vessels should be attempted. 1. If a long 6 French sheath is still in place in the com-

mon carotid artery, the intervention may be performed through this access.

2. For tortuous or calci fi ed arteries in the petrous por-tion of the distal internal carotid artery, a sheath in the common carotid may not provide suf fi cient support. In such cases a 6 Fr guiding catheter is positioned at the bifurcation of the carotid artery. A straight stiff Amplatz wire is placed inside a 4 Fr Berenstein catheter. The Berenstein catheter is used to steer the Amplatz wire into the internal carotid artery. The guiding catheter is then telescoped over the Berenstein and advanced to the internal carotid artery.

3. A hydrophilic wire is loaded into an over-the-wire balloon or Transit catheter (Cordis Endovascular, Miami Lake, FL). This system is advanced through a tuohy borst to the tip of the guide.

4. The balloon should be of small caliber than the ves-sel. With a balloon-to-vessel ratio of 0.8.

Fig. 8.8 Digital subtraction angiogram demonstrating occlusion of the left middle cerebral artery

Fig. 8.7 Angiogram after the use of an aspiration device to remove debris from the embolic protection device. Equal fi lling of the inter-nal and external carotid arteries demonstrates resolution of slow fl ow


5. The hydrophilic wire is carefully directed past the occlusion.

6. The wire is removed from the balloon catheter and the contrast dye is injected through the lumen to con fi rm that the distal tip of the balloon catheter is in a vessel.

7. At this point a non-hydrophilic wire may be replaced though the wire lumen of the balloon. Hydrophilic wires are more likely to cause wire-tip perforations, so these wires should be removed when possible. It may be bene fi cial to choose a more supportive wire, such as a balanced heavy weight or Sport (Abbott Vascular, Abbott Park, IL).

8. The balloon is then positioned across the occlusion of the artery and in fl ated. High-pressure in fl ations are not required. In fact they are to be avoided in the intracerebral vessels.

9. Follow-up angiography is performed to assess if ade-quate angiographic result has been obtained. If lesion has normal fl ow, without dissection and less than 50 % stenosis, this is a suf fi cient angiographic result (Fig. 8.9 ).

10. If post-angioplasty angiography demonstrates a per-sistent fi lling defect that is consistent with thrombus, the interventionalist may consider the administration of thrombolytic drugs.

11. An over-the-wire balloon or a Transit catheter (Cordis Endovascular, Miami Lakes) is brought to the point of occlusion over the wire that is present.

12. Once at the point of occlusion, the wire is removed.

13. The lumen of this catheter is aspirated to assure that no residual air bubbles are present.

14. Tissue Plasminogen Activator (tPA) is slowly injected in 1- or 2-mg increments. Rapid bolus injection must be avoided as this will likely result in re fl ux of the drug and possible running off into non-obstructed vessels with brisker fl ow. Thus, the effective drug delivery at the desired point is diminished. The drug should be suf fi ciently diluted so that 2 mg of tPA are present in 10 mL of solution.

15. Angiography is performed intermittently to assess progress. As much as 5 mg or possibly 10 mg may be administered depending on the size of the thrombotic embolus.

16. If angiography does not demonstrate that throm-bolytic therapy is making progress, the intervention-alist must remember that the embolus may be atherosclerotic in nature and not amenable to thrombolytic therapy. In this case additional throm-bolytic only increases the risk.

Fig. 8.9 Right panel : Digital subtraction angiogram demonstrating occlusion of the left middle cerebral artery. Middle panel : Balloon in fl ated in the middle cerebral artery to treat the occlusion. Left

panel : Digital subtraction angiogram after angioplasty demonstrat-ing reestablishment of fl ow to the middle cerebral artery


Case

The patient is a 62-year-old man who is referred for con-sultation regarding a TIA 2 weeks ago. He has a history of chronic obstructive pulmonary disease that requires the use of home oxygen therapy. Carotid ultrasound demonstrated a 70–79 % stenosis. He was brought to the catheterization laboratory; angiography con fi rmed a severe stenosis of the internal carotid artery (Fig. 8.10 ). There is a type I arch. 1. A 5 Fr Vitek catheter was loaded into a 6 Fr shuttle

sheath (Cook Medical, Bloomington, IN) to engage the common carotid artery.

2. An 0.035″ stiff-angled Glidewire (Terumo, Somerset, NJ) was advanced into the common carotid artery and the Vitek catheter was advanced over the wire.

3. The shuttle sheath was then advanced over the Vitek catheter in a telescoping fashion.

4. The patient underwent carotid artery stenting using a distal embolic protection device in the usual manner as described in the previous chapter. Upon completion of fi nal angiograms, the shuttle sheath was removed. The patient immediately reported a sharp pain in the right neck. During questioning about the pain, the patient developed a dense left-sided hemiparesis.

5. The 5 Fr Vitek catheter is reinserted to perform angiog-raphy. A dissection in the proximal portion of the com-mon carotid artery is revealed (Fig. 8.11 ).

6. The shuttle sheath was advanced again near the ostium of the common carotid artery.

7. An 0.014 balanced heavy weight (BHW) coronary guidewire was steered through the true lumen beyond the dissection. If adequate position in the true lumen cannot be assured with angiography from the sheath, then injection through an over-the-wire system should be performed to con fi rm the position in the true lumen.

8. An 8 × 18 mm balloon-expandable stent was advanced over the wire and positioned to cover the dissection. The stent was deployed at 12 atm. A balloon-expand-able stent was chosen in this case due to the position of the dissection. Near the ostium of the common carotid is located within the trunk of the body and protected from external compression. Balloon-expandable stents also allow for more precise deployment of position as opposed to self-expanding stents. For dissections in the cervical portions of the carotid artery, self-expand-ing stents should be chosen. The cervical portions of the carotid are subject to twisting of the neck and exter-

nal compression. Self-expanding stents will resume their designed shape as opposed to balloon-expandable stents which may be crimped by these forces.

9. Angiography con fi rmed resolution of dissection (Fig. 8.12 ). The patient’s hemiparesis immediately resolved.

Fig. 8.10 Digital subtraction angiogram demonstrating severe stenosis of the internal carotid artery


Fig. 8.11 Digital subtraction angiogram demonstrating dissection of the common carotid artery

Fig. 8.12 Digital subtraction angiogram demonstrating fi nal angio-graphic result after successful stenting of the common carotid artery


Intracranial Hemorrhage

Patients with focal neurologic fi ndings after CAS in the setting of normal blood pressure should be considered to have intracranial hemorrhage. The presence of headache or

loss of consciousness is even more concerning. If symptoms occur within the fi rst 2 h after CAS, blood should be drawn to measure the activated clotting time. If it is still prolonged, reversal with protamine should be administered. These patients should be brought to the computed tomographic (CT) scanner immediately for a non-contrast CT scan (Fig. 8.13 ). The radiologist must be informed that the patient has undergone CAS, as the radiographic contrast agent used for the CAS procedure may create artifact that may be con-strued to be hemorrhage. If there is evidence of intracranial hemorrhage, an immediate neurosurgical consultation should be obtained.

Summary

The cases discussed above describe the mechanical compli-cations that may occur with CAS and provide an approach to endovascular treatment of those complications, spasm, obstructed EPD, macro-emboli to the intracerebral vessels, and dissection of the carotid. The interventionalist who per-forms CAS must be familiar with these methods to secure an angiographically and clinically successful procedure.

Reference

1. Yadav JS, Wholey MH, Kuntz RE, Fayad P, Katzen BT, Mishkel GJ, et al. Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med. 2004;351(15):1493–501.

Fig. 8.13 Non-contrast computed tomography scan of the head dem-onstrating intracranial hemorrhage. Although contrast from angiogra-phy may enhance the brain on non-contrast CT imaging, the evidence of mass effect and sulcal effacement suggests that the high attenuation mass in the left hemisphere is not due to artifact

Documents

Endovascular Interventions || Carotid Artery Stenting: Complication Management