Technical challenges in a program of carotid artery stenting

From the Eastern Vascular Society

Technical challenges in a program of carotid arterystentingH. Michael Choi, MD,a Robert W. Hobson II, MD,a,b Jonathan Goldstein, MD,b

Elie Chakhtoura, MD,b Brajesh K. Lal, MD,a Paul B. Haser, MD,a,b Salvador A. Cuadra, MD,a

Frank T. Padberg, Jr, MD,a and Zafar Jamil, MDa,b Newark, NJ

Objectives: Successful carotid artery stenting (CAS) involves gaining access to the common carotid artery, characterizingand crossing the lesion, deploying an anti-embolic device and stent, and retrieving the anti-embolic device. These steps arecritical determinants of the complexity of the procedure. The frequency with which technical challenges are encounteredduring CAS is ill-defined. The purpose of this investigation was to review the incidence and types of technical challengesencountered during CAS and determine their effect on outcome.Methods: Data were prospectively collected for 194 consecutive CAS procedures (177 patients) and separated into group1, standard CAS technique, and group 2, procedures with technical challenges requiring modifications to the technique.Technical challenges were defined as difficult femoral arterial access (aortoiliac occlusive disease), complex aortic archanatomy (elongated or bovine arch, deep takeoff of the innominate artery, tandem stenoses (CCA, innominate artery),difficult internal carotid artery anatomy (tortuosity, high-grade stenosis), and circumferential internal carotid arterycalcification. The incidence of technical challenges, types of technical modifications required, and effect on outcomes weredetermined.Results: Fifty technically challenging situations (26%) were encountered in 194 CAS procedures (group 2), which requiredadvanced technical skills. Standard methodols were used in the other 144 procedures (group 1, 74%). No significantdifferences in 30-day stroke and death rates were noted between the groups (group 1, 3.1%; group 2, 2.0%; P � .564).Conclusions: Twenty-six percent of the procedures required a modification in the standard technique for successful CAS.Circumferential calcification and severe tortuosity continue to be relative contraindications to CAS. Recognition of thesetechnical challenges and increasing facility with the methods to manage them will enable expanded use of CAS withoutincreased morbidity and mortality. ( J Vasc Surg 2004;40:746-51.)

Data from prospective randomized trials have con-firmed the efficacy of carotid endarterectomy (CEA) totreat symptomatic1-3 and asymptomatic4,5 carotid occlu-sive disease. As a potentially less invasive alternative, carotidartery stenting (CAS) is currently being investigated inrandomized clinical trials in patients at high risk6 and goodrisk.7-10 However, subsets of patients, including those withrecurrent stenosis, anatomically high carotid lesions, his-tory of neck irradiation, and severe medical comorbid con-ditions, may benefit from CAS,11 and are currently beingmanaged with these techniques.

The Society for Vascular Surgery has published currentminimal catheter and guide wire skills for vascular surgeonsfor performance of interventional procedures.12 However,the Society has not defined the minimal requirements nec-essary for the performance of CAS. CAS requires advancedskills as well as clinical judgment in the selection of patients.We have documented our recommended procedural out-

From the Division of Vascular Surgery, Department of Surgery,a UMDNJ-New Jersey Medical School, and the Division of Cardiology, Departmentof Medicine,b St Michael’s Medical Center.

Competition of interest: none.Presented at the Eighteenth Annual Meeting of the Eastern Vascular Soci-

ety, Philadelphia, Pa, Apr 29-May 2, 2004.Reprint requests: Robert W. Hobson II, MD, Division of Vascular Surgery,

UMDNJ-New Jersey Medical School, ADMC, Bldg 6, Rm 620, 30Bergen St, Newark, NJ 07101 (e-mail: [email protected]).

0741-5214/$30.00Copyright © 2004 by The Society for Vascular Surgery.doi:10.1016/j.jvs.2004.07.021

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line for CAS.13,14 However, modified techniques are fre-quently required, which prompted a review of our clinicalseries.

METHODS

Performance of CAS at our institution was initiated bya team of vascular surgeons and cardiologists in 1996.During the period September 1996 to March 2004, 194consecutive CAS procedures were performed in 177 pa-tients. Indications for CAS included high-grade carotidrecurrent stenosis after previous CEA in 110 patients(57%); high risk in patients with medical comorbid condi-tions, as previously defined by our group,15 in 53 patients(27%); radiation-induced stenoses in 13 patients (7%); pa-tients at normal risk with symptomatic stenosis randomizedto CAS in 9 instances (4.5%); in-stent recurrent stenosis in6 patients (3%); and anatomically high bifurcation in 3patients (1.5%). Asymptomatic stenoses were stented in128 patients (66%), and symptomatic lesions in 66 patients(34%). This cohort of patients included 99 men (56%) and78 women (44%), with mean age of 71 years (range, 45-93years).

CAS protocol. CAS was performed with modifica-tions as described.13,14 Patients received pretreatment withaspirin and clopidogrel. Combined antiplatelet medicationwas continued for a minimum of 4 weeks after CAS, andaspirin therapy alone thereafter. Procedures were per-formed in the awake patient with local anesthesia for the

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femoral puncture site, with occasional supplemental mini-mal intravenous sedation.

Standard retrograde access was performed in the com-mon femoral artery, and a 6F vascular sheath (Cordis) wasinserted. Aortic arch angiography was generally performedwith a 5F pigtail catheter (Cook). Weight-adjusted heparinwas administered (60 U/kg), with activated clotting timemaintained at 225 to 300 seconds throughout the proce-dure. A 0.035-inch, 145-cm Wholey modified guide wire(Mallinckrodt) in a 5F Vitek catheter (Cook) was intro-duced for selective cannulation of the common carotidartery (CCA). The Wholey guide wire was commonly ex-changed for a 0.035-inch, 260-cm Connors guide wire(Meditech/Boston Scientific) for advancement of the Vitekcatheter into the CCA and a 6F 90cm length Raabe sheath(Cook Inc.) was advanced over the Vitek and Connorsguide wire into the CCA. Digital angiography was per-formed to confirm the severity of carotid stenosis, andpre-procedural cerebral angiograms were also obtained atthis time. The stenoses were crossed with anti-embolicdevices (AED) mounted on a 0.014-inch wire with deploy-ment of the AED in the internal carotid artery (ICA), distalto the stenosis. An ACCUNET (Guidant) anti-embolicfilter device was used in all cases in which the ACCULINKstents (Guidant) were used. A Filterwire (Boston Scientific)or PercuSurge Guardwire (Medtronics) was used in cases inwhich Wallstents (Boston Scientific) were delivered. Thestent was treated with post-deployment angioplasty with 5to 5.5 � 20-mm Ultra-soft balloons (Boston Scientific)inflated to 8 to 10 atm. A completion angiogram wasroutinely obtained, and the AED was re-sheathed andremoved. Ipsilateral cervical and intracranial carotid an-giography was performed to assess technical success and toexclude distal cerebral embolization. Post-procedure, pa-tients were monitored in an intermediate care unit over-night, and duplex ultrasound scanning of the cervical ca-rotid artery and stent was performed the followingmorning, with subsequent discharge thereafter.

Modified procedural techniques. Procedures werecategorized according to the above protocol (group 1, n �144) or modified (group 2, n � 50) on the basis ofassignment to 1 of 6 clinical categories (Table). Technical

Table I. Technical challenges and required modifications

Technical challenges

Category Description n

1 High-grade stenosis 242 Complex aortic arch anatomy 12

3 Difficult femoral artery access 7

4 Tandem stenotic lesions 35 Circumferential calcification 26 Internal carotid artery tortuosity 2

CCA, Common carotid artery; CEA, carotid endarterectomy.

modifications were documented, and results for groups 1and 2, including 30-day stroke and death rates, were as-sessed for statistical significance with the Fisher exact test.

Category 1. Category 1 included high-grade (�80%-90%; minimal lumen diameter �1.0 mm) stenosis thatprecluded passage of the AED (n � 24). The ICA stenosiswas crossed with an 0.014-inch high-torque floppy“buddy” wire (Cordis), and predilation was performedwith a 2.5-mm or 3-mm low-profile coronary balloon(Boston Scientific). The stenosis was then crossed with theAED using the buddy wire to assist its passage. The 0.014-inch high-torque floppy wire was then removed, and theAED deployed.

Category 2. This category included complex aorticarch anatomy, bovine configuration, or more proximalorigin of the innominate artery (type 3) (n � 12). The CCAor innominate artery was cannulated with a 5F 100-cmJB-2 (Boston Scientific), 5F 100-cm Berenstein (Cordis),or 5F 100-cm Simmons-2 (Boston Scientific) catheter.

Category 3. This category included patients withcompromised femoral access (n � 7). Three patients un-derwent treatment with transbrachial techniques, and 4patients with direct surgical exposure of the CCA. Brachialartery exposures were performed in the cardiac catheteriza-tion laboratory with use of local anesthesia. Carotid expo-sures were performed with local anesthesia, with placementof a 6F vascular sheath by means of standard techniques inthe operating room with C-arm technology. Brachial arteryexposure and access was obtained ipsilateral to the carotidstenosis in 2 patients, and brachial arterial access was ob-tained contralateral to the carotid stenosis in a third patient.An arteriotomy was made in the brachial artery, and an 8Fsheath was inserted. A Wholey wire over a 7F LIMAcatheter (Cordis) was used to access the ipsilateral CCA in2 patients, and a 5F Vitek catheter (Cook) was used tocannulate the CCA in the contralateral case. AEDs couldnot be safely placed in these patients, because of arterialtortuosity. Two balloon-mounted stents (Genesis; BostonScientific) were placed, and 1 Wallstent (Boston Scientific)was placed to cover ICA stenoses.

Category 4. This category included tandem stenoses(n � 3). Patients with tandem stenoses (Fig 1, A and B)

rformance of carotid artery stenting

Technical modifications

Technicalchallenges (%) Description n

48 Buddy wire with predilation 2424 Alternative catheters 11

Direct CCA cutdown 114 Direct CCA cutdown 4

Transbrachial access 36 Multiple stents 34 Elective CEA 24 Elective CEA 1

in pe

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received 2 Wallstents (Boston Scientific). Two patientsunderwent standard treatment, but 1 patient required acutdown because of a proximal CCA lesion, which wastreated in retrograde fashion with a Wallstent, and thesheath was then adjusted anterograde for management ofthe ICA stenosis with a second Wallstent.

Category 5. This category included ICA tortuosity (n� 2). One patient had greater than 90-degree angulation,with redundancy of the ICA on pretreatment angiograms(Fig 2). This resulted in cancellation of the CAS procedureand performance of CEA with posterior wall plication andsynthetic patching. The other patient with tortuous anat-omy on angiograms demonstrated a lesser degree of steno-sis (40%), and is being observed with serial carotid duplexultrasound scans.

Category 6. This category included ICA circumferentialcalcification (n � 2). One patient underwent CAS (Fig 3), andwas observed to have 40% residual stenosis on the post-procedure angiogram. This stenosis progressed and becameassociated with distal in-stent recurrent stenosis greater than80% 6 months after CAS. CEA with removal of the stent andpatch angioplasty was performed. In the other patient circum-ferential calcification was diagnosed at intraprocedural an-giography, and the CAS procedure was terminated. Thispatient underwent CEA preferentially.

RESULTS

The technical success rate for CAS was 98% (190 of194). Procedures were canceled in 3 patients, and immedi-ate CEA was performed because of tortuosity in 1 patientand circumferential calcification in 1 patient. Three patientsunderwent transbrachial CAS procedures successfully, and

Fig 2. Carotid angiogram demonstrates a tortuous internal ca-rotid artery (ICA; arrow) in a patient with symptomatic high-grade stenosis.

Fig 1. A, Selective carotid arteriogram confirms tandem stenoses(arrows) in the common carotid artery (CCA) and internal carotidartery (ICA) in a patient with a history of neck irradiation. B, Com-pletion arteriogram after placement of stents in the CCA and ICA.

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in 4 patients CAS was performed through surgical CCAexposure. Advanced interventional techniques were re-quired in 26% of our procedures (50 of 194), and thetechnical modifications necessary are summarized in theTable.

One patient in group 1 died suddenly of an apparentacute myocardial infarction 10 days after discharge, and asecond patient died after evacuation of a retroperitonealhematoma complicated with fatal intracranial hemorrhage2 days after CAS. Two non-disabling strokes also occurredin group 1; no strokes were observed in group 2. Onepatient in group 2, with severe chronic obstructive pulmo-nary disease, died of respiratory complications of pneumo-nia and congestive heart failure 15 days after discharge afterCAS. There were no differences in 30-day stroke and deathrates between group 1 (4 of 127, 3.1%) and group 2 (1 of50, 2%; P � .564). Periprocedural stent thrombosis was notobserved. One patient required removal of the stent, be-cause of in-stent recurrent stenosis accompanied by endar-terectomy of the calcified plaque 6 months after the originalCAS procedure. Hematomas developed in 4 patients ingroup 1. Two patients required operative repair, and theother 2 patients required transfusions but nonoperativemanagement. One patient with a groin hematoma in group2 required blood transfusion but not operative interven-tion. Other medical complications, including transient bra-dycardia and hypotension, were noted in fewer than onethird of patients, and were equally balanced betweengroups, without contributing to more serious adverseevents. Contrast agent–induced renal failure did not occurin either group.

Fig 3. Selective carotid angiogram demonstrates circumferentialplaque calcification in a patient with symptomatic high-gradestenosis.

DISCUSSION

Our program in CAS was initiated in 1996 through acollaborative effort of vascular surgeons, neurologists, andcardiologists. Initially our cases included primarily recur-rent stenosis after previous CEA, and thereafter was ex-panded to include other indications, such as radiation-induced stenosis, anatomically high lesions above thesecond cervical vertebra, and patients with more severemedical comorbid conditions. While some smaller clinicalseries, including our cases,16 have reported low complica-tion rates in patients with recurrent stenosis after CEA,collected data17 from multiple centers confirm a 30-daystroke and death rate of 3.7% in 358 patients. These data arecomparable to complications reported in patients with ath-erosclerotic stenosis, which emphasizes the importance ofapplying our technical recommendations to all patientsundergoing CAS.

Review of our clinical experience with CAS demon-strated that in 50 procedures (26%) technical modificationsto our usual protocol were required. Technical success wasachieved in 98% (190 of 194) of procedures, and no differ-ences in 30-day stroke and death rates were noted betweenthe groups (group 1, 3.1%; group 2, 2.0%; P � .564).Circumferentially calcified plaques and severe tortuositywere identified as contraindications to CAS. These contra-indications to CAS are based on anecdotal observationsfrom our clinical series, and will require further confirma-tion by other clinicians. Data from this clinical series dem-onstrate comparability with recently published results. Cre-monesi et al18 reported a 1.1% stroke and death rate and a99.5% technical success rate, and Wholey et al19 reviewedthe world experience by questionnaire and reported a3.98% stroke and death rate, with a technical success rate of98.9% in 12,254 cases.

The most commonly encountered technical challengewas high-grade stenosis that impeded safe placement of anAED (category 1). Although predilatation was used inthese cases to facilitate subsequent passage of AEDs, only 7of 194 (3.6%) cases were managed without the recom-mended placement of an AED. These devices are usedroutinely in CAS, and mounting evidence supports theiruse in all CAS procedures. While data were self-reportedfrom 53 centers, Wholey et al19 reported a 30-day strokerate of 3.22%, and death rate of 6.93%, in patients withsymptomatic disease, with and without cerebral protection.Comparable data from patients with asymptomatic diseasewere 2.51% and 4.78, respectively. A recent clinical alertwas posted by the EVA-3S investigators,20 because ofstroke and death rates that were 3.9 times higher withoutcerebral protection in the early part of their trial, andrecommended avoidance of CAS in the absence of an AED.While nearly half of our cases composed category 1, manyof our patients were managed in trial protocols that re-quired use of specific AEDs. SAPPHIRE investigators didnot report as high an incidence of difficulty in placement ofAEDs. However, this may have been related to the lowerincidence of angiographically confirmed stenosis greater

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than 80% to 90%,21 thereby easing the passage of a first-generation AED. Because the profile of AEDs decreasesfrom first-generation devices (generally 5F) to rapid ex-change systems (generally 3.0F-3.7F), we anticipate a de-crease in the number of these cases.

Complex aortic arch anatomy (category 2) was man-aged with use of alternative catheters, which facilitated theCAS procedures. Compromised femoral arterial access (cat-egory 3) can be managed with alternative techniques whentransfemoral access cannot be achieved. Surgical exposureof the CCA has been reported as a safe alternative.22 Thetransbrachial exposure also has its proponents; however, itsperformance precluded use of an AED in our patients,which might increase complications in a larger series. How-ever, Al-Mubarek et al23 reported using a distal balloonoccluder (Percusurge; Medtronics) during transbrachialCAS. Other opportunities for successful CAS include thetransradial approach, as described by Levy et al.24

Tandem stenoses (category 4) were managed with mul-tiple stents. While this required an alternative plan, the useof 2 or 3 stents to cover extensive or tandem stenosesappears to be well tolerated without increased complica-tions.

Circumferential calcification and severe tortuosity (cat-egories 5 and 6) of the carotid artery became contraindica-tions for CAS in our series. This has also been documentedand reported by d’Audiffret et al.25 In their experience withCAS, 2 patients required conversion to open endarterec-tomy because of residual stenosis and kinking. Althoughsome case reports advocate use of CAS for kinked ICA,26

treatment with endarterectomy is recommended, particu-larly when the tortuousity exceeds 90 degrees. Our experi-ence with CAS in the presence of a circumferential calcifiedcarotid plaque resulted in unacceptable subsequent devel-opment of in-stent recurrent stenosis. This patient ulti-mately required endarterectomy. Another patient in ourrecent experience has undergone CEA, and 2 additionalpatients did not undergo CAS because of angiographicallyobserved circumferential calcification.

Basic catheter and guide wire skills are required beforelearning techniques for CAS.13 These skills are possessed byvascular surgeons who have separately acquired the skills orhave graduated from accredited fellowships in vascular sur-gery. Cardiologists who have completed fellowships ininterventional cardiology are similarly able to proceed.Further analysis of data from training programs will beessential to confirm these impressions.

The appreciation of pathophysiologic features and non-invasive diagnosis of carotid occlusive disease by our groupalso contributed to our program’s success. While basic skillsare acceptable for performance of most CAS procedures,advanced techniques are necessary to perform CAS in asmany as one fourth of patients. CAS in patients included inthese categories should be deferred if the operator is inex-perienced or is initiating a program in CAS. However, asthese additional skills are acquired, CAS can be performedwithout an increased incidence of complications.

REFERENCES

1. North American Symptomatic Carotid Endarterectomy Trial Collabora-tors. Beneficial effect of carotid endarterectomy in symptomatic patientswith high-grade carotid stenosis. N Engl J Med 1991;325:445-53.

2. European Carotid Surgery Trialist’s Collaborative Group. MRC Euro-pean Carotid Surgery Trial: interim results for symptomatic patientswith severe (70-99%) or with mild (0-29%) carotid stenosis. Lancet1991;337:1235-43.

3. Mayberg MR, Wilson SE, Yatsu F, Weiss DG, Messina L, Hershey LA,et al. Carotid endarterectomy and prevention of cerebral ischemia insymptomatic carotid stenosis. JAMA 1991;266:3289-94.

4. Hobson RW II, Weiss DG, Fields WS, Goldstone J, Moore WS, TowneJB, et al. Efficacy of carotid endarterectomy for asymptomatic carotidstenosis. The Veterans Affair Cooperative Study Group. N Engl J Med1993;328:221-7.

5. Executive Committee for the Asymptomatic Carotid AtherosclerosisStudy. Endarterectomy for asymptomatic carotid artery stenosis. JAMA1995;273:1421-8.

6. Yadav JS. Carotid stenting in high-risk patients: design and rationale ofthe SAPPHIRE trial. Cleve Clin J Med 2004;71(suppl 1):S45-6.

7. Hobson RW II. CREST (Carotid Revascularization Endarterectomyversus Stent Trial): background, design, and current status. Semin VascSurg 2000;13:139-43.

8. CAVATAS Investigators. Endovascular versus surgical treatment inpatients with carotid stenosis in the Carotid Artery and Vertebral ArteryTransluminal Angioplasty Study (CAVATAS). a randomized trial. Lan-cet 2001;357:1729-37.

9. Hobson RW II. Rational and status of randomized clinical trials incarotid artery stenting. Semin Vasc Surg 2003;16:311-6.

10. Ringleb PA, Kunze A, Allenberg JR, Hennerici MG, Jansen O, MaurerPC, et al. Evaluation of stent-protected angioplasty for therapy ofsymptomatic stenoses of the carotid artery: SPACE and other random-ized trials. Nervenartz 2003;74:482-8.

11. Veith FJ, Amor M, Ohki T, Beebe HG, Bell PR, Bolia A, et al. Currentstatus of carotid bifurcation angioplasty and stenting based on a con-sensus of opinion leaders. J Vasc Surg 2001;33(2 suppl):S111-6.

12. White RA, Hodgson KJ, Ahn SS, Hobson RW II, Veith FJ. Endovas-cular interventions training and credentialing for vascular surgeons. JVasc Surg 1999;29:177-86.

13. Hobson RW II, Goldstein J, Jamil Z, Lee BC, Padberg FT Jr, HannaAK, et al. Carotid restenosis: operative and endovascular management.J Vasc Surg 1999;29:228-38.

14. Hobson RW II, Lal BK, Chakhtoura EY, Goldstein J, Kubicka R, HaserPB, et al. Carotid artery closure for endarterectomy does not influenceresults of angioplasty-stenting for restenosis. J Vasc Surg 2002;35:435-8.

15. Hobson RW II, Lal BK, Chaktoura EY, Goldstein J, Haser PB, KubickaR, et al. Carotid artery stenting: analysis of data for 105 patients at highrisk. J Vasc Surg 2003;37:1234-9.

16. Hobson RW II, Goldstein J, Jamil Z, Lee BC, Padberg FT Jr, PappasPJ, et al. Carotid restenosis: operative and endovascular management. JVasc Surg 1999;29:228-38.

17. New G, Roubin GS, Iyer SS, Vitek JJ, Wholey MH, Diethrich EB, et al.Safety, efficacy and durability of carotid artery stenting for restenosisfollowing carotid endarterectomy: a multicenter study. J Endovasc Ther2000;7:345-52.

18. Cremonesi A, Manetti R, Castriota F, Setacci C. Protected carotidstenting: clinical advantages and complications of embolic protectiondevices in 442 consecutive patients. Stroke 2003;34:1936-43.

19. Wholey MH, Al-Mubarek N, Wholey MH. Updated review of theglobal carotid artery stent registry. Cathet Cardiovasc Interv 2003;60:259-66.

20. Mas JL, Chatellier G, Branchereau A, Becquemin JP, Bonneville JF,Crochet D, et al. Carotid angioplasty and stenting with and withoutcerebral protection: clinical alert from the Endarterectomy Versus An-gioplasty in Patients with Severe Carotid Stenosis (EVA-3S) trial. Stroke2004;35:E18-21.

21. Public Advisory Committee of the Food and Drug Administration.Circulatory System Device Panel meeting, Gaithersburg, Md, Apr 21,2004.

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22. Stecker MS, Lalka SG, Agarwal DM, Johnson MS, Willing SJ. Stentplacement in common carotid and internal carotid artery stenoses withthe use of an open transcervical approach in a patient with previousendarterectomy. J Vasc Interv Radiol 2002;13:413-7.

23. Al-Mubarek N, Vitek JJ, Iyer SS, New G, Roubin GS. Carotid stentingwith distal-balloon protection via the transbrachial approach. J Endo-vasc Ther 2001;8:571-5.

24. Levy EI, Kim SH, Bendok RB, Qureshi AI, Guterman LR, HopkinsLN. Transradial stenting of the cervical internal carotid artery: technical

case report. Neurosurgery 2003;53:448-52.25. d’Audiffret A, Desgranges P, Kobeiter H, Becquemin JP. Technical

aspects and current results of carotid stenting. J Vasc Surg 2001;33:1001-7.

26. Ramazin-Ali A, Schillinger M, Haumer M, Wilfort A, Minar E. Carotidstenting in a case of combined kinking and stenosis. Cardiovasc IntervRadiol 2001;24:197-9.

Submitted Apr 29, 2004; accepted Jul 13, 2004.

DISCUSSION

Dr Daniel B. Walsh (Lebanon, NH). The first question thatcomes to my mind is, How many of these technical difficultiescould you anticipate prior to the procedure? It seems to me thatcertainly tortuosity, calcification, those kinds of things, are readilyseen with preoperative duplex scanning.

Dr Hung M. Choi. All of our patients undergo preoperativeduplex scanning. We are now more vigilant, and can predict manyof these cases, especially tortuosity and calcification, as you men-tioned, with preoperative duplex scanning or MRA.

Dr Sean D. O’Donnell (Washington, DC). I may havemissed. I didn’t see how many of your difficult cases were due totype B or C arches. And I was wondering what you would suggestin the way of guides or other techniques to deal with the type B andC arch.

Dr Choi. In our series the bovine and type B or C archesnumbered 12, and constituted the second most common technicalchallenge. For our standard cases, we used a Vitek-type catheterand 0.035-inch Wholey or glide wire. However, for the moredifficult arches we have used a JB-2, Simmons, or Berensteincatheter and an 0.035-inch Amplatz Connors wire. In our experi-ence, these modifications in technique have helped facilitate can-nulations and stent deliveries without increasing stroke risk.

Dr Manish Mehta (Albany, NY). Over the years we’ve cer-tainly learned a lot from your institution regarding refining thetechniques of carotid stenting, so I think we all appreciate that.

There are a few technical points. We do things a little differ-ently, and I think we can do it better on our end, so we needed yourinput on that.

First, predilate, never predilate, or only predilate if needed?Second, sizing the balloon to the lesion. You always have

poststenotic dilatation. We always run into trouble, saying, Do westay with the 4-mm balloon? Do we go to 4.5 mm? Do we go to 5mm? Because it looks seductive. And we try to stay on the lowerend, just to avoid dissections and other problems. But I’m just notsure what the right thing to do here is.

Third, do you guys use atropine routinely? If you don’t, at thetime of doing the angioplasty to maintain hemodynamic stabilityand prevent bradycardia?

Fourth, I know you put a quarter by the neck. We used to dosimilar things; we used to use a dime. I trained at Montefiore, and

that’s what Tak used to do. But there’s a graduate wire, and thereare other wires that have markers on them. I think that might helpwith a more precise measurement, especially because there are a lotof times that you need that.

And I know I’ve read your papers in the past, or papers fromyour institution, about management of in-stent stenosis or recur-rent in-stent stenosis, with angioplasty versus carotid endarterec-tomy. And I wonder if you can comment on that. How do youdecide whether you’re going to try angioplasty again versus backoff? Is it the second time, the third time? And what’s your experi-ence?

Dr Choi. To your first question, to pre-dilate or not, with thefirst-generation anti-embolic devices, we generally have pre-di-lated. These anti-embolic devices have profiles that exceed 5F.However, the newer devices, the filter wire and the new generationACCUNET for example, are in the 3.0F to 3.5F side, and havegenerally not required pre-dilation prior to placement of an anti-embolic device.

Your second question was about the poststent angioplasty. Wealso tend to undersize angioplasty balloons. However, we generallyuse 5.0-mm to 5.5-mm balloons, and stay within the confines ofthe stent to prevent dissection. In so doing, we have not observedarterial disruptions or dissections.

Third, we generally administer atropine (0.5-1.0 mg IV) priorto use of balloon angioplasty or stent deployment when bradycar-dia or hypotension occasionally are observed. A reference diameteris useful, and a coin taped to the neck or the 6F sheath arecommonly used for this purpose.

And your last question was regarding recurrent stenosis. Gen-erally, in-stent recurrent restenosis (�80%) is managed with bal-loon angioplasty. Our experience was previously documented [JVasc Surg 2003;38:1162-9]. Life table analysis predicted in-stentrecurrent stenosis greater than 80% in 6.4% of patients at 60months. Repeat angioplasty was performed once in 3 patients, 3times in 1 patient, and angioplasty with repeat stenting in 1 patient,without complications. As can be seen from our review, mostinstances of in-stent recurrent stenosis occur early after CAS, andcan be managed successfully with endovascular techniques.