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Surgical Management of Acute Complications and Critical Restenosis following Carotid Artery Stenting
ANNALSof VASCULAR SURGERY n latemationl Jeuraal of Yascaler $organf1
Surgical Management of Acute Complications and Critical Restenosis following Carotid Artery Stenting Erik L. Owens, MD, L2 Norman H. Kumins, MD, L2 John J. Bergan, MD, L2 and Steve R. Sparks, MD,]'2 San Diego, California
Carotid artery angioplasty with stenting (CAS) is being increasingly used in the treatment of extracranial carotid artery stenosis. As in other catheter-based approaches to the treatment of arterial disease, surgical intervention may be required because of either acute complications or correct critical restenosis. We have reviewed our experience managing early complications and critical inostent restenoses after CAS in a tertiary care university hospital and a Veterans Affairs Medical Center. During the last 5 years, 22 carotid arteries (21 patients) underwent CAS. One patient developed thrombosis and rupture of the carotid artery during stenting. Two other patients (3 arteries) developed critical restenosis within 12 months. Subsequent surgical reconstructions included an internal carotid artery (ICA)-to-external carotid artery (ECA) transposition and a common carotid artery (CCA)-to-ICA bypass with reversed saphenous vein (RSV). The patient who underwent CCA-to-ICA bypass later required subclavian-to-tCA bypass because of rapidly progressive intimal hyperplasia and subsequent occlusion of the CCA. The other patient has not had surgical repair because of his deteriorating condition and significant comorbidities. During the same time period, two additional patients were referred from outside institutions specifically for surgical intervention after carotid stenting. One had delayed rupture of the carotid artery 1 day after stenting and underwent urgent surgical repair. Another patient had early, critical restenosis within the stent and underwent placement of a CCA-to-ICA interposition graft using RSV. Acute treatment failures after CAS can be successfully managed using standard surgical techniques. Patients who develop critical in-stent restenosis requiring surgical repair may need more challenging surgical reconstructions to maintain cerebral perfusion.
INTRODUCTION The indications for carotid e n d a r t e r e c t o m y (CEA) are well defined following the publication of large, multicenter, randomized trials for both symptom-
~Division of Vascular Surgery, Department of Surgery, University of California, San Diego, CA. 2 Section of Vascular Surgery, VA San Diego Healthcare System, San Diego, CA. Presented at the Annual meeting of the Southern California Vascular Surgical Society, Santa Barbara, CA, April 27-29, 200I. Correspondence to: E.L. Owens, MD, Chief, Surgical Service (112), VA San Diego Healthcare System, VASDHS (i12) 3350 La Jolla Village 168
atic and asymptomatic disease. >3 Carotid artery angioplasty with stenting (CAS) has recently emerged as an alternative t r e a t m e n t option for patients with carotid stenosis. 4 The reported stroke rate a r o u n d the time of CAS varies b e t w e e n 1- and
Drive, San Diego, CA 92161, USA. Phone: 858/552-8585, ext. 3621, Fax: 858-552-4317, E-mail: [email protected]. Ann Vasc Surg 2002; 16:168-I75 DO[: 10.i007/si0016-001-0152-2 9 Annals of Vascular Surge~. Inc. Published online: March 15, 2002
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15%. 4~2 In addition to concerns regarding periprocedural neurologic complications, the durability of CAS has not been well established. Restenosis rates are not well k n o w n and the optimal m a n a g e m e n t of this potential o u t c o m e is not yet defined. 13'14 Repeat angioplasty, CEA, and carotid artery reconstruction h a v e all b e e n used to treat restenosis after CAS.~Sd9 A large, multicenter trial is currently p l a n n e d to study the efficacy of CAS. 2~ If the results of this trial (or others) d e m o n s t r a t e c o m p a r a b l e safety and efficacy to that of CEA, CAS will certainly gain m o r e widespread acceptance. Even if CAS is not ultimately used in the routine t r e a t m e n t of carotid artery stenosis, it is likely that CAS will continue to be used to treat select subsets of patients d e e m e d nonsurgical patients. Surgeons, m a y therefore be increasingly asked to m a n a g e patients w h o experience either complications a r o u n d the time of CAS or w h o develop critical restenosis after CAS within the stented carotid artery (in-stent restenosis). In this series of case reports we describe our experience in a c o m b i n e d university and Veterans Affairs (VA) healthcare system with the evaluation and t r e a t m e n t of patients w h o came to the attention of the vascular surgeons after u n d e r g o i n g carotid angioplasty and/ or stenting. The reported cases occurred over a 5-year period from 1996 t h r o u g h 2000. During this time, formal carotid artery angioplasty or stent trials w e r e not being conducted at either institution. The vascular surgeons in this healthcare system advocated the judicious use of CAS and reserved CAS for only those patients w h o had either comorbidities or surgical a n a t o m y that they felt m a d e CEA prohibitive. O t h e r clinicians, however, were able to refer patients directly to the interventionalist for CAS. A retrospective review of the medical charts s h o w that 22 patients (23 arteries) u n d e r w e n t CAS during the 5-year period in either the VA Medical Center or the two university hospitals. Of the 5 patients reported, here, three patients (4 arteries) came from this set of 22 patients. The remaining two patients (2 arteries) were referred from other area hospitals.
ferred to the vascular surgeons for progressive neck swelling ipsilateral to the stented carotid artery. He had no neurologic deficits. A duplex ultrasound revealed a localized h e m a t o m a at the carotid bifurcation with no evidence of extraluminal flow within the h e m a t o m a . Flow within the stented area a p p e a r e d normal. He was t a k e n directly to the operating room. Once the h e m a t o m a was evacuated, active bleeding was seen from the anterior surface of the distal internal carotid artery (ICA). A p p r o x i m a t e l y one-half of the stent circumference was seen protruding t h r o u g h the anterior wall of the ICA. The ICA was o p e n e d p r o x i m a l and distal to the stent. The overlying anterior surface of the ICA was t h e n incised a n d the stent was gently extracted. A standard end a r t e r e c t o m y was possible since the r e m a i n i n g walls of the ICA had b e e n minimally damaged. Several repair sutures were, required, h o w e v e r , along the distal anterior ICA w h e r e the stent had disrupted the artery wall. The patient's recovery was uneventful.
CASE REPORTS
Patient 3
Patient 1
A 70-year-old male u n d e r w e n t CAS with a Palmaz stent at an outside hospital for a s y m p t o m a t i c 70% stenosis. The procedure was reportedly completed w i t h o u t complication. The next day, he was re-
Patient 2
A 65-year-old male u n d e r w e n t CAS for a s y m p tomatic 70% left ICA stenosis in p r e p a r a t i o n for c o r o n a r y artery bypass. During CAS, t h r o m b u s was n o t e d within the stent shortly after d e p l o y m e n t . The patient b e g a n to experience right u p p e r extremity weakness. Local thrombolysis and repeat angioplasty of the area p r o d u c e d no significant i m p r o v e m e n t a n d eventually resulted in evidence of contrast extravasation. Vascular surgery consultation was requested. The patient was transferred to the operating r o o m w i t h o u t r e m o v i n g the intraluminal devices. Only m i n i m a l bleeding was present f r o m a small defect in the anterior ICA. Once the arteries were clamped, the wire and sheath were r e m o v e d from the femoral artery access site. The carotid bifurcation was opened, the stent was removed, and the ICA was allowed to back-bleed. A small a m o u n t of t h r o m b u s was retrieved from the distal ICA. A s h u n t was placed and a standard e n d a r t e r e c t o m y was performed. T h r o m b u s was present within the stent at the time of removal. The patient had only fine m o t o r defecits in the right h a n d after 6 m o n t h s .
A 72-year-old male u n d e r w e n t CAS for a s y m p tomatic carotid stenosis. At the time of d e p l o y m e n t , the stent was placed across the carotid bifurcation, placing the external carotid artery (ECA) w h a t is typically t e r m e d stent-jaiI. The patient did well initially. However, duplex surveillance at 1 year re-
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Fig. 1. A Arteriography d e m o n s t r a t i n g 65% stenosis of ICA. B Postprocedure arteriography s h o w i n g a widely p a t e n t carotid system. C Arteriography d e m o n s t r a t i n g in-stent restenosis 7 m o n t h s after CAS.
vealed >9O% in-stent stenosis with the most significant stenosis occurring at the p r o x i m a l end of the stent in the c o m m o n carotid artery (CCA). It was also n o t e d that the EGA was occluded. The patient was referred for vascular surgery evaluation. Since the stent h a d b e e n in place for nearly a year, a standard e n d a r t e r e c t o m y was felt to be not possible. This patient u n d e r w e n t a n interposition graft with reversed s a p h e n o u s vein (RSV) and h a d an u n e v e n t f u l postoperative recovery. The findings at the time of operation confirmed that a standard CEA w o u l d not h a v e b e e n possible. This was primarily due to the intense i n f l a m m a t o r y response involving the entire circumference of the arteries, especially in the area of the smaller-caliber distal ICA. Patient 4 R i g h t s i d e . A 64-year-old male presented to the vascular surgeons at the San Diego Veteran Affairs Medical Center after u n d e r g o i n g several extracranial cerebrovascular interventions by other physicians. He initially presented with 60-70% stenosis of the right ICA and >90% stenosis of the left ICA d o c u m e n t e d by duplex ultrasonography. He h a d no s y m p t o m s attributable to either lesion. Arteriography confirmed a 70% stenosis in the right ICA (Fig. IA). The left ICA stenosis appeared to be > 9 0 % . The patient first u n d e r w e n t carotid angioplasty and stenting of the right ICA. The ICA was stented with a Palmaz stent. No complications occurred and the post-procedure arteriography revealed a widely patent carotid system (Fig. 1B). Aspirin at 325 mg/ day was administered after the procedure. The patient was referred to the vascular surgeons 7 m o n t h s after CAS with in-stent restenosis. Du-
plex u l t r a s o n o g r a p h y d e m o n s t r a t e d >90% stenosis based on a p e a k systolic velocity (PSV) of 400 cm/ sec and an end diastolic velocity (EDV) of 198 cm/ sec. Arteriography confirmed these findings (Fig. IC). The patient was a s y m p t o m a t i c but with the rapid d e v e l o p m e n t of critical in-stent restenosis, it was felt that surgical reconstruction of the right carotid was indicated. The stent had b e e n placed entirely within the proximal ICA a n d did not p r o t r u d e into the bifurcation. An u n i n v o l v e d portion of distal ICA was felt to be surgically accessible a n d the CCA and ECA were both disease-free. It was felt that these factors m a d e reconstruction with an ICA-to-ECA transposition possible. At operation, the c o m m o n , internal, and external carotid arteries were exposed t h r o u g h a standard CEA incision. The area a r o u n d the stented portion of the ICA was associated with dense inf l a m m a t o r y tissue that m a d e dissection difficult. A standard e n d a r t e r e c t o m y was impractical, as the stent was firmly e m b e d d e d in the l u m e n of the ICA and its r e m o v a l would h a v e d a m a g e d the entire circumference of the artery. The ICA-to-ECA transposition provided in-line flow from the CCA to the ICA. In addition, this reconstruction provided an all-arterial reconstruction w i t h o u t prosthetic material in a patient w h o had d e m o n s t r a t e d the p r o p e n s i t y to form severe intimal hyperplasia. The p a t i e n t recovered uneventfully and s h o w e d no signs of restenosis after 8 months, w h e n arteriography was p e r f o r m e d to evaluate the contralateral side (Fig. 2). Patient 4 L e f t side. The same 64-year-old male u n d e r w e n t left CEA {or the a s y m p t o m a t i c > 9 0 % ICA stenosis
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Fig. 2. There are no signs of restenosis 8 months after ICA-to-ECA transposition with arteriography performed to evaluate the contralateral carotid artery.
Fig. 3. Arteriography demonstrating >90% stenosis of left ICA. shortly after the right CAS procedure (Fig. 3). At the initial duplex surveillance 3 m o n t h s after CEA, the PSV within the endarterectomized left ICA was 382 cm/sec and the EDV was 142 cm/sec, representing early >80% restenosis. The patient was referred for arteriography.
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The degree of stenosis was confirmed to be critical and the patient u n d e r w e n t angioplasty w i t h o u t stent placement. Three m o n t h s after angioplasty, duplex surveillance of the left ICA once again identified critical restenosis with PSV >500 cm/sec. At this time, the vascular surgeons were asked to participate in a p l a n n e d repeat CEA or reconstruction. As expected, the carotid bifurcation was intensely inflamed and scarred. Vascular control was accomplished at sites r e m o t e to the inflamed bifurcation. The carotid bifurcation was o p e n e d and no identifiable e n d a r t e r e c t o m y plane could be established. Plans for repeat CEA were a b a n d o n e d . A portion of s a p h e n o u s vein was prep a r e d and interposed from the proximal CCA to the distal ICA. In addition, the ECA was a n a s t o m o s e d to the vein graft in an end-to-side fashion. Intraoperative duplex u l t r a s o n o g r a p h y indi-cated a PSV of 90-100 cm/sec in the vein graft and distal ICA. The patient did well postoperatively. Within 1 m o n t h , duplex surveillance s h o w e d a PSV of 120 cm/sec in the reconstructed ICA. Three m o n t h s postoperatively, however, repeat duplex surveillance revealed art obstructive w a v e f o r m in the m o s t proximal CCA and a stenotic area at the CCA-vein graft anastomosis with a PSV of >500 cm/sec and EDV of >200 cm/sec. Flow was retrograde in the ECA, with sluggish antegrade flow in the ICA. At this time, the patient c o m p l a i n e d of blurry vision in the ipsilateral eye. He had no o t h e r focal cerebral or visual symptoms. An ophthalmologic evaluation revealed no other source for his blurry vision and confirmed the suspicion that retinal ischemia was the probable cause. A discussion was held with the patient regarding a n o t h e r a t t e m p t at carotid reconstruction with the goal of alleviating his visual s y m p t o m s . An arteriogram was obtained to confirm the duplex findings and better define the a n a t o m y . By the time of arteriography, the patient's, CCA h a d occluded w i t h o u t any n e w symptoms. Flow was m a i n t a i n e d in his reconstructed carotid bifurcation retrograde from the ECA into the ICA as h a d b e e n seen in the previous duplex e x a m (Fig. 4A). The patient was functioning at a very high level, including driving and golfing. He w a n t e d i m p r o v e m e n t in his vision if possible. A subclav i a n - t o - c a r o t i d bifurcation bypass graft to using p o l y t e t r a f l u o r o t h y l e n e (PTFE) was thus performed. The distal PTFE graft was actually anast o m o s e d to the wall of the previous vein graft in an end-to-side fashion (Fig. 4B). Postoperatively, the patient had complete resolution of the blurry vision.
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Fig. 4. A Arteriography demonstrating occluded right CCA but with flow to ICA maintained via EGA. Note large ipsilateral vertebral artery. B Intraoperative arteriography of PTFE bypass from subclavian artery to previously reconstructed carotid bifurcation.
Patient 5
The Vascular Lab at the San Diego Veterans Medical Center provided surveillance carotid imaging for this elderly, institutionalized male after he u n d e r w e n t a right CEA in 1992. During surveillance, he developed bilateral CCA stenoses just proximal to each bifurcation. Each carotid bifurcation r e m a i n e d essentially disease-free. Because of his p o o r health no i n t e r v e n t i o n was considered until it was noted during a surveillance duplex e x a m that his left carotid system, was occluded. He r e m a i n e d asymptomatic. At that same visit, velocities within the right CCA lesion were also n o t e d to h a v e increased dramatically. Peak systolic velocities in the midCCA were in the 400-420 cm/sec range and the EDV was I40-150 cm/sec. Given his frail health, a decision was m a d e to obtain an arteriogram to assess for possible CAS. Arteriography confirmed the duplex findings. The right bifurcation was free of significant disease but a long portion of the CCA was n a r r o w e d by a focal stenosis just below the bifurcation that corresponded to the high-velocity area. This lesion was felt to be >90% (Fig. 5A). Since he was in such p o o r health, CAS was felt to be a reasonable t r e a t m e n t option. An 8 • 40 Wall stent was therefore placed, with good technical results (Figs. 5B and 5C). Initial duplex surveillance of the stented area s h o w e d a PSV of 211 cm/sec and EDV of 60 cm/sec 6 m o n t h s after CAS. At I year, the velocities in this area had increased to a PSV of 481 cm/sec a n d EDV of I00 cm/sec. These velocities were once again felt to be consistent with significant stenosis. The patient has not u n d e r g o n e s u b s e q u e n t intervention be-
cause of his deteriorating health and because he has r e m a i n e d asymptomatic. If the patient w e r e a better operative candidate, a surgical reconstruction using the subclavian artery as inflow w o u l d m o s t likely be considered to m a i n t a i n cerebral perfusion.
DISCUSSION
CEA is a widely accepted procedure for w h i c h the indications, complications, and overall results h a v e b e e n clearly d o c u m e n t e d . 1-3 If the ultimate result and longtime durability of CEA could be offered in a m i n i m a l l y invasive form, there is little doubt that such a m e t h o d would gain widespread acceptance. Minimally invasive and catheter-based t r e a t m e n t m e t h o d s n o w exist for a wide variety of pathologic states. These disorders w e r e previously treated with o p e n surgical procedures. Less invasive t r e a t m e n t m e t h o d s usually simplify the required anesthetic, thereby decreasing the overall risk of cardiopulm o n a r y complications. In addition, patients typically enjoy reduced hospital stays and r e t u r n to n o r m a l activity sooner. W h e t h e r carotid stenting will provide the same a d v a n t a g e s over CEA is not k n o w n . The overall efficacy a n d safety of these n e w procedures m u s t often be d e t e r m i n e d while b o t h the t e c h n o l o g y and the expertise of the physicians p e r f o r m i n g the procedures are still maturing. Carotid artery stenting has e m e r g e d as a potential, m i n i m a l l y invasive c o u n t e r p a r t to surgical CEA. This t e c h n i q u e gained initial interest in treating patients with prohibitive risks for CEA. These patients were felt to be higher risk because of either significant medical comorbidities or difficult surgical access.
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Fig. 5. A Arteriography demonstrating 90% stenosis in CCA proximal to previous right CEA. The left carotid system is occluded. B Placement of 8 • 40 Wall stent in CCA. C Postdeployment arteriography after Wall stent placement.
Multicentered, r a n d o m i z e d trials to evaluate the use of CAS in patients with m o r e typical surgical risks are being planned, t9 Those clinicians prom o t i n g CAS h o p e that initially poor results will i m p r o v e with m o r e experience, proper case selection, and evolving technology. It m a y be several years before b o t h the overall results of CAS are better k n o w n a n d a consensus regarding acceptable indications for its use emerges. In the m e a n t i m e , CAS will m o s t likely be used in a variety of indications, depending on the experience of the treating physician or institution. W h e n catheter-based modalities are used to treat arterial occlusive disease, surgical i n t e r v e n t i o n m a y be required for either periprocedural complications or restenosis that develops in the treated area. The various technical occurrences that often arise at peripheral sites of catheter-based intervention, such as local dissection, m i n o r extravasation of contrast, and t h r o m b u s formation, m a y not be as well tolerated if they occur during carotid artery manipulations. Earlier surgical referral m a y be required for similar technical occurrences during CAS that, in other anatomical locations, might be clinically insignificant or are treated with additional catheter-based m a n e u v e r s . Standard surgical techniques used during CEA a p p e a r to be a d e q u a t e for m a n a g i n g periprocedural CAS complications such as carotid artery r u p t u r e or t h r o m b u s formation, as the stent has not had time to b e c o m e incorporated into the arterial wall and can thus be easily r e m o v e d . The e n d a r t e r e c t o m y plane will m o s t likely be intact and a standard CEA should be possible.
The cases reported here suggest several technical issues that should be addressed w h e n treating patients with acute complications a r o u n d the time of CAS. If t h r o m b u s is present in the carotid artery, consideration should be given to leaving the intraluminal devices in place until surgical exposure is achieved. This could potentially decrease the chance of dislodging intraarterial t h r o m b u s before the ICA is opened a n d allowed to back-bleed. Also, generous exposure of the arteries should be obtained, since the stent often extends b e y o n d the typical sites of clamping, both proximally and distally. While a shunt was placed in the patient in this series w h o developed a neurologic deficit during CAS, it is unclear w h e t h e r this should be considered the standard approach. The stent edges are sharp, so care should be t a k e n in m a n i p u l a t i n g the arteries. Lastly, reconstruction options and the potential n e e d for conduit should be considered in these situations, since the arteries m a y be circumferentially damaged, thus m a k i n g a standard CEA difficult. After technically successful angioplasty a n d / o r stenting, restenosis of the treated artery is k n o w n to be a potential outcome. 14 In-stent restenosis in the carotid artery, h o w e v e r , would appear to h a v e m o r e profound implications on future surgical reconstruction than in other anatomical locations. An iliac artery angioplasty or stent placement, for example, does not typically complicate future surgical bypass procedures. Since the i n t e r v e n t i o n occurs at sites r e m o t e to the future vascular anastomoses, access to undisturbed inflow and outflow vessels is preserved. An aortofemoral bypass, if necessary, can be easily constructed.
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However, if restenosis occurs in the carotid artery after CAS and repeat intraluminal t r e a t m e n t is not possible or not indicated, surgical options are immediately limited because of the physical presence of the stent. Unlike the acute periprocedural situation, the patient w h o requires surgical intervention m o n t h s or years after CAS m a y not be a candidate for a standard CEA. The i n f l a m m a t o r y reaction within the stented artery causes the stent to become adherent to the arterial wall, thus making stent removal difficult. Even if the stent can be removed, identification of the endarterect o m y plane m a y not be possible. If e n d a r t e r e c t o m y c a n n o t be performed, creative reconstruction options are required for revascularization. In addition, access to a n o r m a l CCA and distal ICA could be limited by the stent itself. This further complicates the carotid reconstruction and could potentially eliminate some, if not all, forms of surgical reconstruction. Currently, no definitive evidence exists concerning the optimal m a n a g e m e n t of in-stent restenosis after CAS. Most reports cite an incidence of restenosis after CAS of about 2-5%. 4'6-11 M e a n follow-up in these series, however, rarely exceeds 1 year. Furthermore, Gil-Peralta et al. noted that 32% of their patients had restenosis of at least 30% after a m e a n of I8.7 months, suggesting that an even higher rate of restenosis m a y occur over the longer term. 5 A recent report by Chaktoura et al. indicated an 8% in-stent restenosis rate after CAS with an average follow-up period of 18 months, z~ Repair options for in-stent restenosis after CAS include additional catheterbased procedures, standard endarterectomy, bypass with prosthetic or vein conduit, or ICA-ECA transposition. Repeat angioplasty and even re-stenting have been used to treat in-stent restenosis after CAS with mixed results. 2~ Reports of surgical interventions in these patients have also been reported. Standard CEA has been used to treat restenosis after CAS. Vale and colleagues reported successful endarterectomy 6 m o n t h s after CAS with the Cook balloon-expandable stainless steel stent. ~5 They noted that the operation was complicated by the length of ICA exposure required, the difficulty in opening the stented artery, and the care necessary in removing the plaque and stent to avoid vessel wall penetration. They n o t e d that the arterial wall was thinned by the stent but that the normal cleavage plane was still present to allow safe but careful endarterectomy. Calvey and Gough, by contrast, reported no difficulty in performing a standard endarterectomy for restenosis after CAS
with a Strecker balloon-expandable stent. ~6 Both C o u m a n s et al. and J o h n s o n et al. reconstructed the carotid artery with a reversed saphenous CCAto-ICA bypass after CAS restenosis, i7,18 If the CCA, ECA, and the distal ICA are diseasefree and are surgically accessible, ECA-ICA transposition represents an excellent option. This approach preserves in-line flow from the CCA to the ICA and provides an all-arterial reconstruction w i t h o u t prosthetic material. Transposition is possible only if the CCA, ECA, and distal ICA are free of stenosis or can easily u n d e r g o endarterectomy. Stents placed across the bifurcation into the CCA or far into the previously normal, distal ICA clearly decrease the likelihood of performing this form of reconstruction.
CONCLUSION During the evolution of CAS, surgeons m a y be increasingly called u p o n to assist with periprocedural complications of carotid angioplasty and stenting. Standard surgical techniques used during routine surgical CEA appear to be sufficient to m a n a g e acute complications. Patients w h o develop critical in-stent restenosis after CAS, however, may require complex carotid reconstructions to maintain cerebral perfusion. The feasibility and type of reconstruction employed are highly dependent on the physical location of the stent and the quality of each individual carotid artery. While these reconstructions are familiar to most vascular surgeons, they are infrequently performed a n d are typically utilized for indications such as t r a u m a or malignancy. The use of these complex reconstructions in patients with carotid occlusive disease w h o have u n d e r g o n e CAS represents a novel application for these types of reconstructions. Surgeons practicing in institutions w h e r e CAS is performed should be aware of these reconstruction options w h e n asked to m a n a g e patients with critical in-stent restenosis after CAS.
REFERENCES 1. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade stenosis. N Engl J Med 1991;325:445-453. 2. Barnett HJ, Taylor DW, Eliasziw M, et al. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. N Engl J Med 1998;339:1415-I425. 3. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid artery stenosis. JAMA I995;273:1421-1428.
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4. Kritpracha B, Beebe HG. Carotid artery stenosis: t r e a t m e n t by angioplasty with or w i t h o u t stent. A n n Vasc Surg 1998; 12:621-624. 5. Gil-Peralta A, Mayol A, Marcos JR, et al. P e r c u t a n e o u s t r a n s l u m i n a l angioplasty of the s y m p t o m a t i c atherosclerotic carotid arteries. Results, complications, and follow-up. Stroke 1996;27:2271-2273. 6. Diethrich EB, Ndiaye M, Reid DB. Stenting in the carotid artery: initial experience in 110 patients. J Endovasc Surg 1996;3:42-62. 7. A1-Mubarak N, Gomez CR, Vitek J J, et al. Stenting of s y m p t o m a t i c stenosis of t h e intracranial internal carotid artery. A m J Neuroradiol 1998;19:1949-1951. 8. Yadav JS, Roubin GS, Iyer S, et al. Elective Stenting of the extracranial carotid arteries. Circulation 1997;21;95:376-381. 9. Bergeron P, B e c q u e m i n JP, J a u s s e r a n JM, et al. Percutan e o u s stenting of the internal carotid artery: the E u r o p e a n CAST I Study. J Endovasc Surg 1999;6:155-159. 10. T h e r o n JG, Payelle GG, C o s k u n O, et al. Carotid artery stenosis: t r e a t m e n t with protected balloon angioplasty a n d stent placement. Radiology 1996;201:627-636. 11. Naylor AR, Bolia A, Abbott RJ, et al. R a n d o m i z e d s t u d y of carotid angioplasty a n d stenting versus carotid endarterectomy: a stopped trial. J Vasc Surg 1998;28:326-334. 12. Jordan WD Jr, Schroeder PT, Fisher WS, et al. A comparison of angioplasty with stenting versus e n d a r t e r e c t o m y for the t r e a t m e n t of carotid artery stenosis. A n n Vasc Surg 1997;11:2-8.
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13. Beebe HG, Kritpracha B. Carotid stenting versus carotid endarterectomy: update on the controversy. Semin Vasc Surg 1998;l 1:46-51. 14. A h n SS, Concepcion B. Indications and results o{ arterial stents for occlusive disease. World J Surg 1996;20:644648. 15. Vale FL, Fisher WS 3rd, Jordan WD Jr, et al. Carotid endarterectomy performed after progressive carotid stenosis following angioplasty a n d stent placernent. Case report. J Neurosurg 1997;87:940-943. 16. Calvey TA, Gough MJ. A late complication of internal carotid artery stenting. J Vasc Surg 1998;27:753-755. 17. C o u m a n s JV, W a t s o n VE, Picken CA, et al. S a p h e n o u s vein interposition graft for recurrent carotid stenosis after prior e n d a r t e r e c t o m y a n d stent placement. Case report. J Neurosurg 1999;90:567-570. 18. J o h n s o n SP, Fujitani RM, Leyendecker JR, et al. Stent deformation a n d intimal hyperplasia complicating t r e a t m e n t of a post-carotid e n d a r t e r e c t o m y intimal flap with a Palmaz stent. J Vasc Surg 1997;25:764-768. 19. Hobson RW 2nd. Carotid angioplasty-stent: clinical experience a n d role for clinical trials. J Vasc Surg 2001;33(2 Suppl):S117-S123. 20. C h a k t o u r a EY, Hobson RW 2nd, Goldstein J, et al. In-stent restenosis after carotid angioplasty: incidence a n d m a n a g e m e n t . J Vase Surg 200i;33:220-225. 21. Raithel D, S c h u n n C, Hetzel G, et al. T r e a t m e n t of restenosis. Zentralbl Chir 2000;i25:270-274.z
Surgical Management of Acute Complications and Critical Restenosis following Carotid Artery Stenting Erik L. Owens, MD, L2 Norman H. Kumins, MD, L2 John J. Bergan, MD, L2 and Steve R. Sparks, MD,]'2 San Diego, California
Carotid artery angioplasty with stenting (CAS) is being increasingly used in the treatment of extracranial carotid artery stenosis. As in other catheter-based approaches to the treatment of arterial disease, surgical intervention may be required because of either acute complications or correct critical restenosis. We have reviewed our experience managing early complications and critical inostent restenoses after CAS in a tertiary care university hospital and a Veterans Affairs Medical Center. During the last 5 years, 22 carotid arteries (21 patients) underwent CAS. One patient developed thrombosis and rupture of the carotid artery during stenting. Two other patients (3 arteries) developed critical restenosis within 12 months. Subsequent surgical reconstructions included an internal carotid artery (ICA)-to-external carotid artery (ECA) transposition and a common carotid artery (CCA)-to-ICA bypass with reversed saphenous vein (RSV). The patient who underwent CCA-to-ICA bypass later required subclavian-to-tCA bypass because of rapidly progressive intimal hyperplasia and subsequent occlusion of the CCA. The other patient has not had surgical repair because of his deteriorating condition and significant comorbidities. During the same time period, two additional patients were referred from outside institutions specifically for surgical intervention after carotid stenting. One had delayed rupture of the carotid artery 1 day after stenting and underwent urgent surgical repair. Another patient had early, critical restenosis within the stent and underwent placement of a CCA-to-ICA interposition graft using RSV. Acute treatment failures after CAS can be successfully managed using standard surgical techniques. Patients who develop critical in-stent restenosis requiring surgical repair may need more challenging surgical reconstructions to maintain cerebral perfusion.
INTRODUCTION The indications for carotid e n d a r t e r e c t o m y (CEA) are well defined following the publication of large, multicenter, randomized trials for both symptom-
~Division of Vascular Surgery, Department of Surgery, University of California, San Diego, CA. 2 Section of Vascular Surgery, VA San Diego Healthcare System, San Diego, CA. Presented at the Annual meeting of the Southern California Vascular Surgical Society, Santa Barbara, CA, April 27-29, 200I. Correspondence to: E.L. Owens, MD, Chief, Surgical Service (112), VA San Diego Healthcare System, VASDHS (i12) 3350 La Jolla Village 168
atic and asymptomatic disease. >3 Carotid artery angioplasty with stenting (CAS) has recently emerged as an alternative t r e a t m e n t option for patients with carotid stenosis. 4 The reported stroke rate a r o u n d the time of CAS varies b e t w e e n 1- and
Drive, San Diego, CA 92161, USA. Phone: 858/552-8585, ext. 3621, Fax: 858-552-4317, E-mail: [email protected]. Ann Vasc Surg 2002; 16:168-I75 DO[: 10.i007/si0016-001-0152-2 9 Annals of Vascular Surge~. Inc. Published online: March 15, 2002
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15%. 4~2 In addition to concerns regarding periprocedural neurologic complications, the durability of CAS has not been well established. Restenosis rates are not well k n o w n and the optimal m a n a g e m e n t of this potential o u t c o m e is not yet defined. 13'14 Repeat angioplasty, CEA, and carotid artery reconstruction h a v e all b e e n used to treat restenosis after CAS.~Sd9 A large, multicenter trial is currently p l a n n e d to study the efficacy of CAS. 2~ If the results of this trial (or others) d e m o n s t r a t e c o m p a r a b l e safety and efficacy to that of CEA, CAS will certainly gain m o r e widespread acceptance. Even if CAS is not ultimately used in the routine t r e a t m e n t of carotid artery stenosis, it is likely that CAS will continue to be used to treat select subsets of patients d e e m e d nonsurgical patients. Surgeons, m a y therefore be increasingly asked to m a n a g e patients w h o experience either complications a r o u n d the time of CAS or w h o develop critical restenosis after CAS within the stented carotid artery (in-stent restenosis). In this series of case reports we describe our experience in a c o m b i n e d university and Veterans Affairs (VA) healthcare system with the evaluation and t r e a t m e n t of patients w h o came to the attention of the vascular surgeons after u n d e r g o i n g carotid angioplasty and/ or stenting. The reported cases occurred over a 5-year period from 1996 t h r o u g h 2000. During this time, formal carotid artery angioplasty or stent trials w e r e not being conducted at either institution. The vascular surgeons in this healthcare system advocated the judicious use of CAS and reserved CAS for only those patients w h o had either comorbidities or surgical a n a t o m y that they felt m a d e CEA prohibitive. O t h e r clinicians, however, were able to refer patients directly to the interventionalist for CAS. A retrospective review of the medical charts s h o w that 22 patients (23 arteries) u n d e r w e n t CAS during the 5-year period in either the VA Medical Center or the two university hospitals. Of the 5 patients reported, here, three patients (4 arteries) came from this set of 22 patients. The remaining two patients (2 arteries) were referred from other area hospitals.
ferred to the vascular surgeons for progressive neck swelling ipsilateral to the stented carotid artery. He had no neurologic deficits. A duplex ultrasound revealed a localized h e m a t o m a at the carotid bifurcation with no evidence of extraluminal flow within the h e m a t o m a . Flow within the stented area a p p e a r e d normal. He was t a k e n directly to the operating room. Once the h e m a t o m a was evacuated, active bleeding was seen from the anterior surface of the distal internal carotid artery (ICA). A p p r o x i m a t e l y one-half of the stent circumference was seen protruding t h r o u g h the anterior wall of the ICA. The ICA was o p e n e d p r o x i m a l and distal to the stent. The overlying anterior surface of the ICA was t h e n incised a n d the stent was gently extracted. A standard end a r t e r e c t o m y was possible since the r e m a i n i n g walls of the ICA had b e e n minimally damaged. Several repair sutures were, required, h o w e v e r , along the distal anterior ICA w h e r e the stent had disrupted the artery wall. The patient's recovery was uneventful.
CASE REPORTS
Patient 3
Patient 1
A 70-year-old male u n d e r w e n t CAS with a Palmaz stent at an outside hospital for a s y m p t o m a t i c 70% stenosis. The procedure was reportedly completed w i t h o u t complication. The next day, he was re-
Patient 2
A 65-year-old male u n d e r w e n t CAS for a s y m p tomatic 70% left ICA stenosis in p r e p a r a t i o n for c o r o n a r y artery bypass. During CAS, t h r o m b u s was n o t e d within the stent shortly after d e p l o y m e n t . The patient b e g a n to experience right u p p e r extremity weakness. Local thrombolysis and repeat angioplasty of the area p r o d u c e d no significant i m p r o v e m e n t a n d eventually resulted in evidence of contrast extravasation. Vascular surgery consultation was requested. The patient was transferred to the operating r o o m w i t h o u t r e m o v i n g the intraluminal devices. Only m i n i m a l bleeding was present f r o m a small defect in the anterior ICA. Once the arteries were clamped, the wire and sheath were r e m o v e d from the femoral artery access site. The carotid bifurcation was opened, the stent was removed, and the ICA was allowed to back-bleed. A small a m o u n t of t h r o m b u s was retrieved from the distal ICA. A s h u n t was placed and a standard e n d a r t e r e c t o m y was performed. T h r o m b u s was present within the stent at the time of removal. The patient had only fine m o t o r defecits in the right h a n d after 6 m o n t h s .
A 72-year-old male u n d e r w e n t CAS for a s y m p tomatic carotid stenosis. At the time of d e p l o y m e n t , the stent was placed across the carotid bifurcation, placing the external carotid artery (ECA) w h a t is typically t e r m e d stent-jaiI. The patient did well initially. However, duplex surveillance at 1 year re-
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:
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Fig. 1. A Arteriography d e m o n s t r a t i n g 65% stenosis of ICA. B Postprocedure arteriography s h o w i n g a widely p a t e n t carotid system. C Arteriography d e m o n s t r a t i n g in-stent restenosis 7 m o n t h s after CAS.
vealed >9O% in-stent stenosis with the most significant stenosis occurring at the p r o x i m a l end of the stent in the c o m m o n carotid artery (CCA). It was also n o t e d that the EGA was occluded. The patient was referred for vascular surgery evaluation. Since the stent h a d b e e n in place for nearly a year, a standard e n d a r t e r e c t o m y was felt to be not possible. This patient u n d e r w e n t a n interposition graft with reversed s a p h e n o u s vein (RSV) and h a d an u n e v e n t f u l postoperative recovery. The findings at the time of operation confirmed that a standard CEA w o u l d not h a v e b e e n possible. This was primarily due to the intense i n f l a m m a t o r y response involving the entire circumference of the arteries, especially in the area of the smaller-caliber distal ICA. Patient 4 R i g h t s i d e . A 64-year-old male presented to the vascular surgeons at the San Diego Veteran Affairs Medical Center after u n d e r g o i n g several extracranial cerebrovascular interventions by other physicians. He initially presented with 60-70% stenosis of the right ICA and >90% stenosis of the left ICA d o c u m e n t e d by duplex ultrasonography. He h a d no s y m p t o m s attributable to either lesion. Arteriography confirmed a 70% stenosis in the right ICA (Fig. IA). The left ICA stenosis appeared to be > 9 0 % . The patient first u n d e r w e n t carotid angioplasty and stenting of the right ICA. The ICA was stented with a Palmaz stent. No complications occurred and the post-procedure arteriography revealed a widely patent carotid system (Fig. 1B). Aspirin at 325 mg/ day was administered after the procedure. The patient was referred to the vascular surgeons 7 m o n t h s after CAS with in-stent restenosis. Du-
plex u l t r a s o n o g r a p h y d e m o n s t r a t e d >90% stenosis based on a p e a k systolic velocity (PSV) of 400 cm/ sec and an end diastolic velocity (EDV) of 198 cm/ sec. Arteriography confirmed these findings (Fig. IC). The patient was a s y m p t o m a t i c but with the rapid d e v e l o p m e n t of critical in-stent restenosis, it was felt that surgical reconstruction of the right carotid was indicated. The stent had b e e n placed entirely within the proximal ICA a n d did not p r o t r u d e into the bifurcation. An u n i n v o l v e d portion of distal ICA was felt to be surgically accessible a n d the CCA and ECA were both disease-free. It was felt that these factors m a d e reconstruction with an ICA-to-ECA transposition possible. At operation, the c o m m o n , internal, and external carotid arteries were exposed t h r o u g h a standard CEA incision. The area a r o u n d the stented portion of the ICA was associated with dense inf l a m m a t o r y tissue that m a d e dissection difficult. A standard e n d a r t e r e c t o m y was impractical, as the stent was firmly e m b e d d e d in the l u m e n of the ICA and its r e m o v a l would h a v e d a m a g e d the entire circumference of the artery. The ICA-to-ECA transposition provided in-line flow from the CCA to the ICA. In addition, this reconstruction provided an all-arterial reconstruction w i t h o u t prosthetic material in a patient w h o had d e m o n s t r a t e d the p r o p e n s i t y to form severe intimal hyperplasia. The p a t i e n t recovered uneventfully and s h o w e d no signs of restenosis after 8 months, w h e n arteriography was p e r f o r m e d to evaluate the contralateral side (Fig. 2). Patient 4 L e f t side. The same 64-year-old male u n d e r w e n t left CEA {or the a s y m p t o m a t i c > 9 0 % ICA stenosis
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Fig. 2. There are no signs of restenosis 8 months after ICA-to-ECA transposition with arteriography performed to evaluate the contralateral carotid artery.
Fig. 3. Arteriography demonstrating >90% stenosis of left ICA. shortly after the right CAS procedure (Fig. 3). At the initial duplex surveillance 3 m o n t h s after CEA, the PSV within the endarterectomized left ICA was 382 cm/sec and the EDV was 142 cm/sec, representing early >80% restenosis. The patient was referred for arteriography.
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The degree of stenosis was confirmed to be critical and the patient u n d e r w e n t angioplasty w i t h o u t stent placement. Three m o n t h s after angioplasty, duplex surveillance of the left ICA once again identified critical restenosis with PSV >500 cm/sec. At this time, the vascular surgeons were asked to participate in a p l a n n e d repeat CEA or reconstruction. As expected, the carotid bifurcation was intensely inflamed and scarred. Vascular control was accomplished at sites r e m o t e to the inflamed bifurcation. The carotid bifurcation was o p e n e d and no identifiable e n d a r t e r e c t o m y plane could be established. Plans for repeat CEA were a b a n d o n e d . A portion of s a p h e n o u s vein was prep a r e d and interposed from the proximal CCA to the distal ICA. In addition, the ECA was a n a s t o m o s e d to the vein graft in an end-to-side fashion. Intraoperative duplex u l t r a s o n o g r a p h y indi-cated a PSV of 90-100 cm/sec in the vein graft and distal ICA. The patient did well postoperatively. Within 1 m o n t h , duplex surveillance s h o w e d a PSV of 120 cm/sec in the reconstructed ICA. Three m o n t h s postoperatively, however, repeat duplex surveillance revealed art obstructive w a v e f o r m in the m o s t proximal CCA and a stenotic area at the CCA-vein graft anastomosis with a PSV of >500 cm/sec and EDV of >200 cm/sec. Flow was retrograde in the ECA, with sluggish antegrade flow in the ICA. At this time, the patient c o m p l a i n e d of blurry vision in the ipsilateral eye. He had no o t h e r focal cerebral or visual symptoms. An ophthalmologic evaluation revealed no other source for his blurry vision and confirmed the suspicion that retinal ischemia was the probable cause. A discussion was held with the patient regarding a n o t h e r a t t e m p t at carotid reconstruction with the goal of alleviating his visual s y m p t o m s . An arteriogram was obtained to confirm the duplex findings and better define the a n a t o m y . By the time of arteriography, the patient's, CCA h a d occluded w i t h o u t any n e w symptoms. Flow was m a i n t a i n e d in his reconstructed carotid bifurcation retrograde from the ECA into the ICA as h a d b e e n seen in the previous duplex e x a m (Fig. 4A). The patient was functioning at a very high level, including driving and golfing. He w a n t e d i m p r o v e m e n t in his vision if possible. A subclav i a n - t o - c a r o t i d bifurcation bypass graft to using p o l y t e t r a f l u o r o t h y l e n e (PTFE) was thus performed. The distal PTFE graft was actually anast o m o s e d to the wall of the previous vein graft in an end-to-side fashion (Fig. 4B). Postoperatively, the patient had complete resolution of the blurry vision.
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Fig. 4. A Arteriography demonstrating occluded right CCA but with flow to ICA maintained via EGA. Note large ipsilateral vertebral artery. B Intraoperative arteriography of PTFE bypass from subclavian artery to previously reconstructed carotid bifurcation.
Patient 5
The Vascular Lab at the San Diego Veterans Medical Center provided surveillance carotid imaging for this elderly, institutionalized male after he u n d e r w e n t a right CEA in 1992. During surveillance, he developed bilateral CCA stenoses just proximal to each bifurcation. Each carotid bifurcation r e m a i n e d essentially disease-free. Because of his p o o r health no i n t e r v e n t i o n was considered until it was noted during a surveillance duplex e x a m that his left carotid system, was occluded. He r e m a i n e d asymptomatic. At that same visit, velocities within the right CCA lesion were also n o t e d to h a v e increased dramatically. Peak systolic velocities in the midCCA were in the 400-420 cm/sec range and the EDV was I40-150 cm/sec. Given his frail health, a decision was m a d e to obtain an arteriogram to assess for possible CAS. Arteriography confirmed the duplex findings. The right bifurcation was free of significant disease but a long portion of the CCA was n a r r o w e d by a focal stenosis just below the bifurcation that corresponded to the high-velocity area. This lesion was felt to be >90% (Fig. 5A). Since he was in such p o o r health, CAS was felt to be a reasonable t r e a t m e n t option. An 8 • 40 Wall stent was therefore placed, with good technical results (Figs. 5B and 5C). Initial duplex surveillance of the stented area s h o w e d a PSV of 211 cm/sec and EDV of 60 cm/sec 6 m o n t h s after CAS. At I year, the velocities in this area had increased to a PSV of 481 cm/sec a n d EDV of I00 cm/sec. These velocities were once again felt to be consistent with significant stenosis. The patient has not u n d e r g o n e s u b s e q u e n t intervention be-
cause of his deteriorating health and because he has r e m a i n e d asymptomatic. If the patient w e r e a better operative candidate, a surgical reconstruction using the subclavian artery as inflow w o u l d m o s t likely be considered to m a i n t a i n cerebral perfusion.
DISCUSSION
CEA is a widely accepted procedure for w h i c h the indications, complications, and overall results h a v e b e e n clearly d o c u m e n t e d . 1-3 If the ultimate result and longtime durability of CEA could be offered in a m i n i m a l l y invasive form, there is little doubt that such a m e t h o d would gain widespread acceptance. Minimally invasive and catheter-based t r e a t m e n t m e t h o d s n o w exist for a wide variety of pathologic states. These disorders w e r e previously treated with o p e n surgical procedures. Less invasive t r e a t m e n t m e t h o d s usually simplify the required anesthetic, thereby decreasing the overall risk of cardiopulm o n a r y complications. In addition, patients typically enjoy reduced hospital stays and r e t u r n to n o r m a l activity sooner. W h e t h e r carotid stenting will provide the same a d v a n t a g e s over CEA is not k n o w n . The overall efficacy a n d safety of these n e w procedures m u s t often be d e t e r m i n e d while b o t h the t e c h n o l o g y and the expertise of the physicians p e r f o r m i n g the procedures are still maturing. Carotid artery stenting has e m e r g e d as a potential, m i n i m a l l y invasive c o u n t e r p a r t to surgical CEA. This t e c h n i q u e gained initial interest in treating patients with prohibitive risks for CEA. These patients were felt to be higher risk because of either significant medical comorbidities or difficult surgical access.
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Fig. 5. A Arteriography demonstrating 90% stenosis in CCA proximal to previous right CEA. The left carotid system is occluded. B Placement of 8 • 40 Wall stent in CCA. C Postdeployment arteriography after Wall stent placement.
Multicentered, r a n d o m i z e d trials to evaluate the use of CAS in patients with m o r e typical surgical risks are being planned, t9 Those clinicians prom o t i n g CAS h o p e that initially poor results will i m p r o v e with m o r e experience, proper case selection, and evolving technology. It m a y be several years before b o t h the overall results of CAS are better k n o w n a n d a consensus regarding acceptable indications for its use emerges. In the m e a n t i m e , CAS will m o s t likely be used in a variety of indications, depending on the experience of the treating physician or institution. W h e n catheter-based modalities are used to treat arterial occlusive disease, surgical i n t e r v e n t i o n m a y be required for either periprocedural complications or restenosis that develops in the treated area. The various technical occurrences that often arise at peripheral sites of catheter-based intervention, such as local dissection, m i n o r extravasation of contrast, and t h r o m b u s formation, m a y not be as well tolerated if they occur during carotid artery manipulations. Earlier surgical referral m a y be required for similar technical occurrences during CAS that, in other anatomical locations, might be clinically insignificant or are treated with additional catheter-based m a n e u v e r s . Standard surgical techniques used during CEA a p p e a r to be a d e q u a t e for m a n a g i n g periprocedural CAS complications such as carotid artery r u p t u r e or t h r o m b u s formation, as the stent has not had time to b e c o m e incorporated into the arterial wall and can thus be easily r e m o v e d . The e n d a r t e r e c t o m y plane will m o s t likely be intact and a standard CEA should be possible.
The cases reported here suggest several technical issues that should be addressed w h e n treating patients with acute complications a r o u n d the time of CAS. If t h r o m b u s is present in the carotid artery, consideration should be given to leaving the intraluminal devices in place until surgical exposure is achieved. This could potentially decrease the chance of dislodging intraarterial t h r o m b u s before the ICA is opened a n d allowed to back-bleed. Also, generous exposure of the arteries should be obtained, since the stent often extends b e y o n d the typical sites of clamping, both proximally and distally. While a shunt was placed in the patient in this series w h o developed a neurologic deficit during CAS, it is unclear w h e t h e r this should be considered the standard approach. The stent edges are sharp, so care should be t a k e n in m a n i p u l a t i n g the arteries. Lastly, reconstruction options and the potential n e e d for conduit should be considered in these situations, since the arteries m a y be circumferentially damaged, thus m a k i n g a standard CEA difficult. After technically successful angioplasty a n d / o r stenting, restenosis of the treated artery is k n o w n to be a potential outcome. 14 In-stent restenosis in the carotid artery, h o w e v e r , would appear to h a v e m o r e profound implications on future surgical reconstruction than in other anatomical locations. An iliac artery angioplasty or stent placement, for example, does not typically complicate future surgical bypass procedures. Since the i n t e r v e n t i o n occurs at sites r e m o t e to the future vascular anastomoses, access to undisturbed inflow and outflow vessels is preserved. An aortofemoral bypass, if necessary, can be easily constructed.
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However, if restenosis occurs in the carotid artery after CAS and repeat intraluminal t r e a t m e n t is not possible or not indicated, surgical options are immediately limited because of the physical presence of the stent. Unlike the acute periprocedural situation, the patient w h o requires surgical intervention m o n t h s or years after CAS m a y not be a candidate for a standard CEA. The i n f l a m m a t o r y reaction within the stented artery causes the stent to become adherent to the arterial wall, thus making stent removal difficult. Even if the stent can be removed, identification of the endarterect o m y plane m a y not be possible. If e n d a r t e r e c t o m y c a n n o t be performed, creative reconstruction options are required for revascularization. In addition, access to a n o r m a l CCA and distal ICA could be limited by the stent itself. This further complicates the carotid reconstruction and could potentially eliminate some, if not all, forms of surgical reconstruction. Currently, no definitive evidence exists concerning the optimal m a n a g e m e n t of in-stent restenosis after CAS. Most reports cite an incidence of restenosis after CAS of about 2-5%. 4'6-11 M e a n follow-up in these series, however, rarely exceeds 1 year. Furthermore, Gil-Peralta et al. noted that 32% of their patients had restenosis of at least 30% after a m e a n of I8.7 months, suggesting that an even higher rate of restenosis m a y occur over the longer term. 5 A recent report by Chaktoura et al. indicated an 8% in-stent restenosis rate after CAS with an average follow-up period of 18 months, z~ Repair options for in-stent restenosis after CAS include additional catheterbased procedures, standard endarterectomy, bypass with prosthetic or vein conduit, or ICA-ECA transposition. Repeat angioplasty and even re-stenting have been used to treat in-stent restenosis after CAS with mixed results. 2~ Reports of surgical interventions in these patients have also been reported. Standard CEA has been used to treat restenosis after CAS. Vale and colleagues reported successful endarterectomy 6 m o n t h s after CAS with the Cook balloon-expandable stainless steel stent. ~5 They noted that the operation was complicated by the length of ICA exposure required, the difficulty in opening the stented artery, and the care necessary in removing the plaque and stent to avoid vessel wall penetration. They n o t e d that the arterial wall was thinned by the stent but that the normal cleavage plane was still present to allow safe but careful endarterectomy. Calvey and Gough, by contrast, reported no difficulty in performing a standard endarterectomy for restenosis after CAS
with a Strecker balloon-expandable stent. ~6 Both C o u m a n s et al. and J o h n s o n et al. reconstructed the carotid artery with a reversed saphenous CCAto-ICA bypass after CAS restenosis, i7,18 If the CCA, ECA, and the distal ICA are diseasefree and are surgically accessible, ECA-ICA transposition represents an excellent option. This approach preserves in-line flow from the CCA to the ICA and provides an all-arterial reconstruction w i t h o u t prosthetic material. Transposition is possible only if the CCA, ECA, and distal ICA are free of stenosis or can easily u n d e r g o endarterectomy. Stents placed across the bifurcation into the CCA or far into the previously normal, distal ICA clearly decrease the likelihood of performing this form of reconstruction.
CONCLUSION During the evolution of CAS, surgeons m a y be increasingly called u p o n to assist with periprocedural complications of carotid angioplasty and stenting. Standard surgical techniques used during routine surgical CEA appear to be sufficient to m a n a g e acute complications. Patients w h o develop critical in-stent restenosis after CAS, however, may require complex carotid reconstructions to maintain cerebral perfusion. The feasibility and type of reconstruction employed are highly dependent on the physical location of the stent and the quality of each individual carotid artery. While these reconstructions are familiar to most vascular surgeons, they are infrequently performed a n d are typically utilized for indications such as t r a u m a or malignancy. The use of these complex reconstructions in patients with carotid occlusive disease w h o have u n d e r g o n e CAS represents a novel application for these types of reconstructions. Surgeons practicing in institutions w h e r e CAS is performed should be aware of these reconstruction options w h e n asked to m a n a g e patients with critical in-stent restenosis after CAS.
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