- Email: [email protected]
Stent-grafts in the Treatment of Emergent or Urgent Carotid Artery Disease: Review of 25 Cases
Stent-grafts in the Treatment of Emergent or Urgent Carotid Artery Disease: Review of 25 Cases Hanno Hoppe, MD, Stanley L. Barnwell, MD, PhD, Gary M. Nesbit, MD, and Bryan D. Petersen, MD
PURPOSE: To report the authors’ initial experience with carotid artery stent-grafts in a comparatively large patient series for the treatment of acute bleeding and impending rupture or the prevention of distal embolization. MATERIALS AND METHODS: This retrospective study was approved by the institutional review boards and performed according to HIPPA standards. Twenty-five patients were treated with 27 carotid artery stent-grafts (Gore Viabahn, n ⴝ 10; Bard Fluency, n ⴝ 9; polytetrafluoroethylene— covered Palmaz, n ⴝ 5; and Wallgraft, n ⴝ 3). Thirteen stent-grafts were placed in patients with carotid blow-out syndrome (including three patients with carotid-airway fistula), 12 in patients with either pseudoaneurysm (n ⴝ 9) or true aneurysm (n ⴝ 3), and two in patients with intractable high-grade bare stent restenosis. RESULTS: The technical success rate was 100% (27 of 27 cases). No acute procedural transient ischemic attacks or strokes occurred. Procedural dissections occurred in two of the 27 cases (7.4%). Short-term complications occurred in three of the 27 cases (11%) (repeat hemorrhage, n ⴝ 2; common carotid artery occlusion, n ⴝ 1). The overall patient mortality rate was 36% (nine of 25 patients, all with carotid blow-out syndrome). Six-month follow-up in 15 of the 16 living patients demonstrated widely patent stent-grafts. Two patients with pseudoaneurysm also demonstrated patent stents at 18- and 33-month follow-up. CONCLUSIONS: Stent-grafts may be useful in the treatment of carotid artery bleeding syndrome, aneurysm, and stenosis, with a high procedural success rate in selected cases. The results of mid-term follow-up are encouraging, but results of long-term follow-up must be evaluated in future studies. J Vasc Interv Radiol 2008; 19:31– 41 Abbreviations:
CCA ⫽ common carotid artery, FDA ⫽ Food and Drug Administration, ICA ⫽ internal carotid artery, PTFE ⫽ polytetrafluoroethylene
RECENTLY, covered stents or stentgrafts have become a more frequent alternative in the treatment of vascular diseases that could once only be treated with surgical intervention. At present, stent-grafts are successfully
From the Dotter Interventional Institute, Oregon Health and Sciences University, L-342, 3181 SW Sam Jackson Park Rd, Portland, OR 97201 (H.H., S.L.B., G.M.N., B.D.P.); and the Department of Angiography, Portland Veterans Administration Medical Center, Portland, OR (B.D.P.). Received March 12, 2007; final revision received August 7, 2007; accepted August 19, 2007. Address correspondence to B.D.P.; E-mail: [email protected] None of the authors have identified a conflict of interest. © SIR, 2008 DOI: 10.1016/j.jvir.2007.08.024
used for the treatment of aneurysm, pseudoaneurysm, vascular injury, and intractable intimal hyperplasia in various vascular beds (1– 6). It has been difficult to place stent-grafts in the carotid artery because of the risk of cerebral infarction resulting from acute dissection, occlusion, or embolism, which may be caused by the large device profile and size and lack of flexibility of delivery systems (3). Additional concerns include the presumed risk of latent occlusion from thrombus formation or intimal hyperplasia. As reported in a previous study (7), carotid stent-grafts had an advantage in lowering the cerebral embolization rate, but had an excessive incidence of in-stent restenosis. The use of stentgrafts in the treatment of carotid artery disease has been previously described
as anecdotal experiences in various case reports (8 –12), whereas we present data from a larger series of patients in whom this technique has been used, including results of mid-term angiographic and clinical follow-up. The purpose of this retrospective study was to evaluate our initial experience with stent-grafts in the carotid artery in a comparatively large patient series with vascular lesions requiring emergent or urgent treatment for acute bleeding or impending rupture or to prevent distal embolization.
MATERIALS AND METHODS Study Population This retrospective study was approved by the institutional review
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Summary of Results in 25 Patients Treated with the Placement of 27 Carotid Artery Stent-Grafts Patient No./ Age/Sex
Indication for Treatment
Location of Stent-Graft
Type of Stent-Graft
Comments
1/61/F
CBS
R CCA/ICA
PTFE Palmaz
2/86/F 3/75/M 4/67/F 5/62/F 6/33/M 7/87/F
CBS CBS CBS CBS CBS CBS CBS CBS
L CCA L CCA L CCA R CCA L CCA R CCA/ICA R CCA L ICA
PTFE Palmaz PTFE Palmaz PTFE Palmaz PTFE Palmaz Fluency Fluency Wallgraft Wallgraft
8/63/F 9/61/M
CBS Carotid-airway fistula
L CCA/ICA R CCA
Wallgraft Fluency
10/64/F 11/52/M 12/68/M 13/20/F
Carotid-airway fistula Carotid-airway fistula Pseudoaneurysm Pseudoaneurysm
Viabahn Viabahn Fluency Viabahn
14/67/M 15/53/M
Pseudoaneurysm Pseudoaneurysm dissection Pseudoaneurysm dissection Pseudoaneurysm stenosis Pseudoaneurysm stenosis Pseudoaneurysm stenosis Pseudoaneurysm dissection Aneurysm Aneurysm Aneurysm In-stent stenosis In-stent stenosis
and
R CCA R CCA L CCA/ICA L ICA (cervical/ petrous) R ICA R ICA (petrous)
Viabahn Fluency
R external carotid artery embolization for pseudoaneurysm L CCA dissection — L CCA embolization — — — Repeat hemorrhage and death L external carotid artery embolization for pseudoaneurysm — Surgical removal of stent-graft without pathologic findings after 10 d because of previous bypass surgery — Repeat hemorrhage — L external carotid artery embolization for bleeding — —
and
L ICA
Viabahn
L petrous ICA dissection
and
R ICA
Viabahn
—
and
L CCA
Fluency
—
and
L CCA
Fluency
—
and
R ICA
Viabahn
—
L ICA (petrous) L ICA (petrous) L CCA L CCA/ICA R ICA
Viabahn Viabahn Fluency Fluency Viabahn
— — — — —
16/44/F 17/47/M 18/63/F 19/67/F 20/57/M 21/55/M 22/74/M 23/65/M 24/65/M 25/80/M
Note.—CBS ⫽ carotid blow-out syndrome, HNC ⫽ head and neck cancer, L ⫽ left, R ⫽ right * Clinical follow-up as of January 2007.
boards and was performed according to Health Insurance Portability and Accountability Act standards. We reviewed the images and medical records from all patients who were treated with stent-grafts in the carotid vasculature from March 1998 to November 2006. Twenty-seven stentgrafts were placed in the common and internal carotid arteries in 25 patients (11 women, 14 men). The mean patient age (⫾standard deviation) was 61 years ⫾ 16.3 (range, 20 – 87 years). Written, informed consent for placement was obtained from all patients. Data for this study were obtained from imaging studies and medical
records. Data were collected and analyzed in terms of overall outcomes and, in addition, categorized according to the indication for stent placement. Indications Twenty-seven stent-grafts were placed in 27 procedures and 25 patients. All cases were emergent or urgent in nature. Thirteen stent-grafts were placed in patients with carotid blow-out syndrome, including three patients with carotid-airway fistulas. These patients were terminally ill with progressive head and neck cancer and had under-
gone multiple surgeries and irradiation. These patients had sentinel hemorrhage or profuse, poorly controlled hemorrhage. They were not surgical candidates because they had an incomplete circle of Willis or contralateral carotid artery occlusion. Three stent-grafts were placed in one patient with bilateral disease. Twelve more patients with either pseudoaneurysm (n ⫽ 9) or true aneurysm (n ⫽ 3) of their common carotid artery (CCA) or internal carotid artery (ICA) were treated to prevent impending rupture. Two other patients had developed intractable high-grade stenoses due to intimal hyperplasia within previously
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Angio Longest Follow-up (mo)
Outcome at Follow-up
Origin and Extension of Disease
Time between Death and Last Procedure
1
Occlusion of R CCA
HNC, extended disease
1 y, 2 mo
Death (primary disease)
HNC, extended disease HNC, extended disease
3 mo 1 y, 6 mo
Death (primary disease) Death (primary disease)
HNC, HNC, HNC, HNC,
5 mo 48 h 6 mo
Death (primary disease) Clinically well at 18 mo Death (procedure related) Death (primary disease)
10 mo 5 mo
Death (primary disease) Death (primary disease)
4
Patent
6
Patent
extended extended extended extended
disease disease disease disease
HNC, extended disease HNC, extended disease
6
Patent
Cause of Death or Results at Clinical Follow-up*
Pending 6
Patent
HNC, extended disease HNC, extended disease Trauma Trauma
6 and 33 6
Patent Patent
Trauma Trauma
Clinically well at 36 mo Clinically well at 24 mo
6
Patent
Atheromatous disease
Clinically well at 40 mo
6 and 18
Patent
Spontaneous
Clinically well at 30 mo
6
Patent
HNC, irradiation
Clinically well at 30 mo
6
Patent
Carotid endarterectomy
Clinically well at 23 mo
6
Patent
Atheromatous disease
Clinically well at 16 mo
6 6 6 6 6
Patent Patent Patent Patent Patent
Atheromatous Atheromatous Atheromatous Atheromatous Atheromatous
Clinically well at 41 Lost to follow-up at Lost to follow-up at Clinically well at 25 Clinically well at 45
placed bare carotid stents, which had failed previous interventions. These patients were then treated with stentgrafts to prevent distal embolism or stroke. Technique Stent placement was performed with the patient under moderate sedation by using intravenous administration of fentanyl and midazolam. Blood pressure, electrocardiographic parameters, arterial oxygen saturation, and respiratory rate were continuously monitored. With use of a percutaneous transfemoral approach, initial di-
24 h
disease disease disease disease disease
agnostic arteriography of the carotid and intracranial vascular anatomy was performed by using a high-resolution biplane, digital subtraction angiography unit (Philips Medical Systems, Bothell, Wash). Stent-graft placement required the placement of large 8.5– 12-F, 80-cm-long delivery sheaths (Cook, Bloomington, Ind) into the common or internal carotid artery. This was generally performed over a stiff 260-cmlong exchange-length guide wire (Amplatz Super Stiff; Boston Scientific, Natick, Mass). Stent-grafts were then deployed across the involved arterial segments (CCA, n ⫽ 12; CCA and ICA, n ⫽ 5; ICA, n ⫽ 10 [including four
Lost to follow-up at 18 mo Death (procedural related) Clinically well at 17 mo Clinically well at 30 mo
mo 39 mo 15 mo mo mo
in the petrous ICA]) by using biplane fluoroscopic angiography with road map guidance. The choice of a particular stent was determined by both the availability and the diameter and length of the target lesion. Five homemade polytetrafluoroethylene (PTFE)– covered Palmaz stents (Cordis, Miami, Fla) were used on a humanitarian basis before receiving U.S. Food and Drug Administration (FDA) approval. The following FDA-approved stent-grafts were used: 10 Viabahn stents (Gore, Newark, Del), nine Fluency stents (Bard, Tempe, Ariz), and three Wallgrafts (Boston Scientific, Minneapolis, Minn). In general, cerebral protection de-
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vices were not usually used in patients with acute bleeding or aneurysmal disease. After receiving FDA approval, distal filter protection devices were used in four patients with lesions associated with stenotic lesions. The Emboshield cerebral protection device (Abbott Laboratories, Abbott Park, Ill) was used in two different patients with complex lesions, that is, high-grade stenoses associated with pseudoaneurysms caused by previous dissection. The Accunet device (Guidant, St Paul, Minn) and the EPI device (Boston Scientific) were used in the two patients who were treated for in-stent restenosis of their carotid stents. After placement of the stent-graft, it was dilated to the normal artery size by using angioplasty balloon catheters, being careful not to dilate outside the confines of the stent-graft. At the conclusion of the procedure, control cerebral and carotid angiograms were obtained for all patients. Heparin was intravenously administered depending on the situation and was not used in patients who were acutely bleeding. Heparin was administered in 15 of the 27 procedures (56%) in patients with more stable lesions in a manner to elevate the activated clotting time to 250 seconds or greater. All patients received 75 mg of clopidogrel orally every day (Plavix; Bristol-Myers Squibb/Sanofi Pharmaceuticals Partnership, New York, NY) for 6 months and 325 mg of aspirin orally every day. Additional external carotid artery embolization was performed in three patients by using Nester coils (Cook) and/or GDC coils (Target Therapeutics, Fremont, Calif). Complications and Follow-up Technical success and procedural complications were collected and recorded. Neurologic complications were categorized as minor and major per SIR reporting standards (13). Complications at follow-up were categorized as shortterm complications if they occurred within 30 days or less after stent-graft placement and as mid-term complications if they occurred more than 30 days after stent-graft placement. Patients were followed up with both clinical and angiographic examinations. Repeat hemorrhage was diagnosed clinically, with computed tomography and/or ultrasonography, or with angiography.
Statistics Data were entered into a worksheet (Excel 2003; Microsoft, Redmond, Wash). Descriptive and summary statistics were calculated (GraphPad InStat V3.0 for Windows; GraphPad, San Diego, Calif) and tables created.
RESULTS Overall Outcomes Results are summarized in the Table. All 27 carotid stent-grafts were placed successfully in 25 patients (Figs 1 and 2). The technical success rate was 100% (27 of 27 cases). No minor or major neurologic complications occurred. Procedural complications occurred in two of the 27 cases (7.4%). In one patient treated for carotid blowout syndrome, a dissection of the proximal CCA was caused by introduction of an 8.5-F sheath, which was subsequently treated with two bare self-expanding nitinol stents (Smart; Cordis). At follow-up, there was normal luminal integrity with only slight filling of the false lumen of the dissection. In a patient with a pseudoaneurysm, the tip of a 0.035-inch guide wire caused a dissection of the petrous ICA, which was subsequently treated with a bare stent (Precise; Cordis). At control angiography, there was excellent flow and no substantial residual dissection. Both patients did well without ischemic or embolic symptoms. Short-term complications occurred in four of the 27 cases (15%). One occlusion of the right CCA occurred within 30 days of placement of a PTFE-covered Palmaz stent for carotid blow-out syndrome (Fig 3). One early rupture with repeat hemorrhage occurred after placement of a Viabahn stent-graft for the treatment of carotid blow-out syndrome with carotid-airway fistula and eventual patient death. This patient had received large amounts of transfused blood products during transportation to our institution for treatment. The stent-graft procedure was uncomplicated and angiography demonstrated the correct placement of the Viabahn, with a patent lumen, excellent blood flow, and no evidence of extravasation. After initial complete cessation of hemorrhage, there was slow repeat bleeding, which built to eventual substantial hemorrhage. Re-
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peat angiography demonstrated no evidence of contrast medium extravasation and the correct placement of the stent. The patient’s activated partial thromboplastin time at this point was 178 seconds, and he was most likely in massive disseminated intravascular coagulopathy secondary to enormous blood loss. The patient was urgently transferred to the operating room for surgical intervention and died within 24 hours. This patient had undergone total laryngectomy with an interposition flap 2 weeks earlier. He was admitted from the emergency department with a flap infection. In the hospital, he had a “Herald bleed” followed by a massive hemorrhage. A massive transfusion protocol was begun, and the patient received more than 20 units of blood products. He was taken to angiography, where bleeding was first controlled with placement of a balloon and then a stent-graft. Because of disseminated intravascular coagulation from the massive transfusion, the infected flap continued to ooze from the margins; however, the massive bleeding was controlled. The patient was taken to the operating room to débride the flap, control the ooze from the margins of the failing surgical flap. In the operating room, the patient had respiratory arrest, primarily due to pulmonary edema and “stiff lungs” from the massive resuscitation efforts and fluid. He could not be revived. At autopsy, the stent-graft could be seen through a large rent or hole in the right carotid artery, in good position, surrounded by necrotic and purulent material. Three stent-grafts were placed in the same patient for bilateral carotid blow-out syndrome. After successful placement of a PTFE-covered Palmaz stent in the left CCA for acute bleeding, repeat hemorrhage occurred 9 days later. Repeat angiography demonstrated slight flow around the balloon-expandable device, which was then expanded from 6 to 8 mm in diameter with a balloon angioplasty catheter. This further expansion of the device resulted in device rupture and massive extravasation. A second PTFE-covered Palmaz stent was placed inside of the first, resulting in control of extravasation with excellent flow. However, after discussion with the referring ear, nose, and throat surgeons and due to the uncertain durability of the new “homemade” device, this device was embolized 1 day later to provide definitive
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Figure 1. Images in a 63-year-old woman (patient no. 8) with laryngeal and tongue cancer. A vein bypass graft was recently placed in her left carotid artery. The left external carotid artery had been previously occluded. She developed massive hemoptysis and was referred for angiography. (a) Angiogram of the left CCA (a-p) demonstrates occlusion of the external carotid artery. A vein patch graft arises from the distal CCA up to the ICA at the level of the lower portion of the jaw (arrowheads). There is a pseudoaneurysm of the distal graft anastomois (arrow). There is no active extravasation beyond the pseudoaneurysm at this point. (b) A 6 ⫻ 50-mm Wallgraft was deployed and dilated by using a 5 ⫻ 40-mm-long vascular balloon. (c) Left carotid angiogram (a-p) obtained after stent-graft deployment demonstrates diminishing flow to the wall of the graft into the pseudoaneurysm. There is continued mild filling of the pseudoaneurysm through the porous Dacron graft material (arrow) because the patient was receiving heparin. (d) Follow-up left carotid angiogram (a-p) obtained the next day demonstrates complete patency of the left CCA, ICA, and bypass graft, with no filling of the pseudoaneurysm. No irregularities, intraluminal filling defects, or other abnormalities are noted. There is excellent flow through the stent-graft.
control of the arterial bleeding. Five months later, another PTFE-covered Palmaz stent was successfully placed in the same patient for contralateral carotid blow-out syndrome. In another patient treated for acute bleeding due to carotid blow-out syndrome, bleeding recurred after it was initially controlled with placement of a Wallgraft in the CCA. This repeat bleeding occurred 48 hours after treatment and resulted in the patient’s death. At autopsy, there was evidence that the tumor had extended cephalad beyond the CCA and into the ICA, to a new or additional bleeding site beyond the distal aspect of the Wallgraft. The initial placement of the Wallgraft was not extended into the ICA due to vessel tortousity and fear of vessel perforation or embolic complication. The patient died 48 hours later. In an “intend-to-treat” analysis, two patients with carotid blow-out syndrome—this patient with the Wallgraft and the patient with the Viabahn mentioned ear-
lier— died related to the procedure, for a procedural-related mortality rate of 8%. The overall patient mortality rate was 36% (nine of 25 patients, all with carotid blow-out syndrome). In one patient with carotid blowout syndrome, surgical removal of the stent-graft was performed 10 days after stent placement because the patient had subsequently undergone a carotid-subclavian bypass and endovascular CCA occlusion to avoid potential stent-graft infection due to a coexistent fistula.
drome and/or airway fistula). Two patients treated for a pseudoaneurysm demonstrated a patent stent at longterm follow-up 18 (Fig 4) and 33 (Fig 5) months after stent-graft placement, respectively. In one patient treated for pseudoaneurysm, angiographic follow-up is still pending, but the patient is alive and asymptomatic at 18 months. The average clinical follow-up time was 28 months (range, 15– 45 months). Three patients were lost to follow-up at 15, 18, and 39 months, respectively.
Follow-up
DISCUSSION
The overall patient mortality rate was 36% (nine of 25 patients, all with carotid blow-out syndrome). At 6-month angiographic follow-up, widely patent stent-grafts were found in 15 patients (11 with aneurysm and/or pseudoaneurysm, two with in-stent restenosis, and two with carotid blow-out syn-
This study represents a rather large experience in the use of stent-grafts for the treatment of patients with bleeding or aneurysmal diseases of the carotid vasculature and demonstrates that stent-grafts can be used as an alternative treatment in a heterogeneous population of patients who would be
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Figure 2. Images in an 80-year-old man (patient no. 25) with right cervical ICA stenosis. (a) Digital subtraction angiogram (lateral projection) of the right carotid artery demonstrates proximal right ICA stenosis (arrow). (b) Right carotid artery angiogram (lateral projection) demonstrates cervical ICA stenosis, which was initially treated with a 10 ⫻ 38-mm Dynalink stent (Abbott Laboratories, Abbott Park, Ill) 5 years earlier, with a good initial result. (c) Right carotid digital subtraction angiogram (lateral projection) obtained 4 years later, in 2005, shows the asymptomatic right ICA in-stent stenosis of 80% (arrow). A stent had been placed in the left CCA (arrowhead) 3 years earlier for a 60% stenosis caused by an ulcerated plaque at the origin of the left ICA. (d) Right carotid angiogram (lateral projection) obtained after angioplasty of the right ICA demonstrates irregular residual stenosis greater than 50% (arrow). (e) A 6 ⫻ 25-mm Viabahn stent-graft was placed within the previously placed Dynalink stent, and angioplasty was performed with a 5.5 ⫻ 20-mm balloon. (f) Right carotid angiogram obtained in the lateral projection after stent-graft placement demonstrates wide patency without abnormality.
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Figure 3. Images in a 61-year-old woman (patient no. 1) with squamous cell carcinoma of the piriform sinus, soft palate, and tongue who underwent surgery and radiation therapy. The woman also has a large orocutaneous fistula. The patient presented to the emergency room with profuse bleeding through her fistula. (a) Angiogram of the right CCA (a-p) demonstrates a pseudoaneurysm (arrow) with early filling extending about the region of the bifurcation in the proximal segment of the right external carotid artery. The pseudoaneurysm fills from the region of the external carotid artery origin before its previous embolization site. There is acute bleeding with contrast medium extravasation (arrowheads). (b) A P424 Palmaz stent-graft covered with thin-walled Gore-Tex was placed with preservation of antegrade flow through the parent vessel and complete closure of the pseudoaneurysm. Right CCA angiogram (a-p) demonstrates restoration of the vessel luminal diameter at the region of the stent approximating the size of the vessel lumen just distal to the stent (arrow). The acute bleeding was stopped. (c) Follow-up CT angiogram (axial projection) obtained 1 month later demonstrates occlusion of the stent-graft (arrow) in the right ICA. There is no external compression of the stent-graft. The patient was asymptomatic.
at high risk for stroke or death with conventional surgical repair. In most patients who presented with acute bleeding, bleeding was controlled with stent-graft placement, either to allow time for elective surgical repair or as a final procedure in these patients with terminal disease. These are difficult patients to control surgically, and our results compare favorably with historic surgical controls and results in this subset of patients with carotid blow-out syndrome or direct carotid artery to airway fistula (14). Carotid blow-out syndrome is a term that has commonly been used to describe cases of rupture of the extracranial carotid artery or its branches. It is a usually regarded as a rare but life-threatening complication of head and neck cancer therapy (12). Various etiologic factors relating to surgery and adjuvant therapy have been implicated. Besides surgical ligation and
permanent balloon occlusion, treatment of carotid blow-out syndrome with stent-grafts has been previously described as anecdotal case reports (3,12). In our study, the mortality rate for patients with carotid blow-out syndrome after endovascular treatment with stent-grafts was 82% (nine of 11). In the literature, the reported mortality rate for this condition ranges from 9% to 100% after various treatment options (14). The mortality rate obtained by Lesley et al (3) was lower than that in our study, but this is due to a different patient cohort. Lesley et al classified patients with carotid blow-out syndrome into three groups. Although most patients in their study were group I or II patients, most of the patients in our study are group III patients. These are patients with extended disease, sentinel hemorrhage, or profuse, poorly controlled hemor-
rhage. The comparison of different subsets of patients with carotid blowout syndrome, however, was not the subject of our study. In our study, repeat hemorrhage after stent-graft placement occurred in three of 13 cases of carotid blow-out syndrome (23%), whereas one patient was successfully treated with another covered stent-graft and two patients eventually died. Before the introduction of covered stent-grafts, emergency surgical ligation or permanent balloon occlusion had been the only therapeutic procedures available for carotid blow-out syndrome, despite the well-documented risk of cerebral ischemia (15). In the study by Chaloupka et al (15), major neurologic complications after surgical ligation of the carotid artery were observed in approximately 60% of patients. In our study, no neurologic complications were observed af-
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Figure 4. Images in a 47-year-old man (patient no. 17) with a right-sided ICA pseudoaneurysm. (a) Right carotid angiogram (a-p) demonstrates an 11 ⫻ 15-mm aneurysm that projects medially and anteriorly to the ICA with a 5-mm neck (arrow). The cervical ICA has persistent stenosis (arrowhead), which measures up to 70% luminal diameter and at least 3 cm in length at the level of the aneurysm. Flow distal to the stenosis in the intracranial ICA is slow but antegrade. (b) A 6 ⫻ 50-mm Viabahn stent-graft was placed in the right ICA. (c) Digital subtraction angiogram (a-p) of the right carotid artery after stent-graft placement. There is a small amount of spasm proximal to the stent-graft (arrow), which resolved over time. A flap is also visible. (d) Digital subtraction angiogram (a-p) of the right carotid artery 18-months after stent-graft placement. The graft is widely patent and without abnormality.
Figure 5. Images in a 67-year-old man (patient no. 14) with a pseudoaneurysm and bleeding of the right ICA caused by surgery (anterior diskectomy). The pseudoaneurysm caused airway compression. (a) Right carotid angiogram (lateral projection) with landmarks demonstrates a right ICA pseudoaneurysm. (b) A 6 ⫻ 25-mm Viabahn stent-graft was placed and the aneurysm successfully excluded. (c) Follow-up image obtained 33 months later demonstrates a widely patent stent-graft. The patient is clinically well at 36 months.
ter endovascular treatment with covered stent-grafts. This is supported by the results of the study by Lesley et al (3), who reported no major stroke in their series of 16 carotid blow-out
cases treated with stents, including two covered stent-grafts. These results imply that stent-grafts may represent an excellent alternative treatment for patients with poor collateral flow who
are at increased risk for stroke with ligation or permanent occlusion. Patients with pseudoaneurysms, true aneurysms, or in-stent restenosis represent a group of patients requiring
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urgent, but less emergent therapy. Many of these patients had either contralateral carotid artery occlusions or lesions located in areas not amenable to conventional surgery, placing them at high risk for complications. All of these patients were treated without transient ischemic episodes or stroke or other major complications. We have records from both clinical and angiographic follow-up in most of our patients, from 6 months to 39 months. In all instances, the stent-grafts have remained patent and patients asymptomatic, establishing a level of durability to the procedure despite the use of different types of stent-grafts. Before the development of endovascular treatment, surgery was the only treatment option for symptomatic or complicated aneurysms of the carotid artery, which may lead to embolic complications, nerve compression, or rupture. In aneurysms of the distal extracranial ICA, surgery is often challenging and may be disabling (16). After surgery, a stroke rate of 5%–15% and a mortality rate of 2%– 4% have been reported (11). Covered stents or stent-grafts are a promising treatment option, especially for distally located aneurysms and dissecting aneurysms. In our study, 12 patients with aneurysms were successfully treated with stent-grafts. No major stroke occurred and no patient died. These 12 procedures were complicated only by one asymptomatic carotid dissection caused by a guide wire that was successfully treated with a bare stent. The use of stent-grafts for the treatment of a carotid aneurysm or pseudoaneurysm has been reported as anecdotal experiences or small patient series (17). Martin et al (10) reported on a case of successful treatment of a carotid artery aneurysm with a stentgraft after carotid endarterectomy. Gralla et al (9) described the use of a covered stent to treat an ICA aneurysm with life-threatening hemorrhages in a pediatric patient. Scavee et al (18) successfully obliterated a pseudoaneurysm with preservation of the carotid artery by using a stent-graft. Simionato et al (19) successfully treated a posttraumatic wide-necked carotid aneurysm with a stent-graft. Layton et al (8) described one patient with neurofibromatosis and ruptured pseudoaneurysm from tumor invasion
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and another with traumatic pseudoaneurysm, both of whom were successfully treated by using two stent-grafts each. A small series of endovascular treatment with stent-grafts of five extracranial ICA aneurysms in four patients was reported by Bergeron et al (11). All stent-grafts remained patent and no adverse events were observed at follow-up after more than 1 year. One early endoleak was observed and treated with covered stent extension. In our study, two patients were treated for in-stent restenosis with a covered stent-graft. No adverse events occurred and follow-up demonstrated excellent results. Layton et al (8) reported one case of intractable intimal hyperplasia causing in-stent restenosis despite multiple treatments with conventional angioplasty. A stent-graft was placed across the focal stenosis within the previously placed wall stent. When recurrent high-grade stenosis occurred within the portion of the Wallstent that was not covered with the stent-graft, additional angioplasty and intraarterial brachytherapy were successfully performed. Intimal hyperplasia, however, did not recur in the portion of the carotid artery treated with the covered stent-graft. When this case series began in 1998, no FDA-approved commercial devices were available for use. Our earliest cases were performed with balloonexpandable Palmaz stents covered with pre-expanded PTFE. These devices were used on a humanitarian basis to prevent potentially life-threatening bleeding, all in patients with head and neck cancers. In the short-term, these devices proved to work quite well, preventing bleeding without dislodgement, migration, or compression. Because these patients had a limited life expectancy, the long-term durability of these devices was not tested. Marotta et al (20) reported on the placement of an autologous veincovered Palmaz stent in a patient with carotid blow-out syndrome, resulting in immediate exclusion of an ICA pseudoaneurysm. Results of 1-month follow-up helped confirm the successful exclusion of the pseudoaneurysm and carotid patency without stenosis. This technique may help prevent stent-related thromboembolism and recurrent carotid blow-out syndrome but must be investigated in further studies.
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The first commercially available FDA-approved device was the Boston Scientific Wallgraft. This self-expanding device is made of woven stainless steel with a porous Dacron covering. Although it still requires a large delivery sheath (larger than 9 F), because of its longitudinal flexibility the deliverability of this device was better than that of our homemade device. Once deployed, this flexibility also enabled better conformability to arterial walls, especially those with tortuous anatomy. The biggest disadvantage of the device, however, was the porous Dacron covering. Although Dacron is a commonly used as a vascular graft material, in this setting, the Dacron is “pre-clotted” with the patient’s blood to prevent leakage through the fabric. This is not possible when used as the covering of the Wallgraft, and the porosity made it unsuitable for use in an acute bleeding situation such as carotid blow-out syndrome because blood will simply pour through the fabric, not clotting in a timely fashion to prevent stroke or exsanguination (21). Furthermore, when used as an endograft in the peripheral circulation, it is known to incite an inflammatory response, which may lead to early vessel occlusion (22). The flexible and self-expanding characteristics of the Wallgraft were an improvement over our balloon-expandable device, but the porosity and inflammatory nature of the covering made it unsuitable and we used it only when no other device was available. The next two commercially available stent-grafts were the Gore Viabahn (which received FDA approval for the treatment of tracheobronchial strictures on April 25, 2005) and the Bard Fluency (which received FDA approval for the treatment of tracheobronchial strictures on June 19, 2003). Both of these devices are made of selfexpanding nitinol covered with PTFE. Although it still requires large delivery sheaths, both the flexibility and conformability are improved compared to that of the Wallgraft, and the PTFE covering is substantially nonadhesive to flowing blood. The Gore device was the first of these two to become available in a long delivery sheath (110 cm) necessary for placement in the carotid artery. It requires an 8 –12-F sheath for the diameters used in the carotid circulation. The
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Bard Fluency device recently became available in long delivery lengths (117 cm) and requires a 9-F sheath in diameters of 6 –10 mm. Although the delivery mechanisms of the two devices differ, we now use these two devices nearly interchangeably. Of interest, Gore is now offering the Viabahn with a lower profile delivery system through a 7-F sheath for 6-mm stentgrafts and an 8-F sheath for 7– 8-mm stent-grafts. In the present study, self-expanding stents were used preferentially over balloon-mounted stents because of a variety of technical and biomechanical factors. Self-expanding stents more easily accommodate varying diameters of the carotid artery, especially at the transition from the CCA to ICA. Self-expanding stents are more forgiving when determining the necessary diameter and demonstrate superior flexibility in conforming to tortuous segments of the carotid segment (3). In addition, a self-expanding stent is safer than a balloon-mounted stent because of potential arterial injury resulting from high balloon inflation pressures needed for stent deployment. This is particularly important in patients with carotid blow-out syndrome because the target arterial segment is already weakened by the underlying disease (14,15). Kwok et al (23) reported on a case of carotid blow-out syndrome treated with a balloon-expandable covered stent-graft (Jomed, Helsingborg, Sweden) that offered no protection to high pressure. Extravasation at both ends of the stent with persistent transoral hemorrhage occurred and eventually required endovascular occlusion of the CCA. The placement of carotid stentgrafts requires a variety of favorable anatomic and pathophysiologic factors such as common femoral and iliac arterial anatomy that will permit the placement of a large-caliber (9 –12-F) sheath, simple curvature of the aortic arch, relatively straight carotid and brachiocephalic arteries, and the lack of coexistent atherosclerotic or postradiation stenosis. Therefore, more widespread use of self-expanding covered stent-grafts will require technology improvements, including lower profile delivery systems, increased overall flexibility, and enhanced deliverability. There are several limitations of this
study. First, the study is retrospective in nature and therefore not controlled for selection bias, detection of events, and data collection. Second, although 27 stent-grafts were placed, complications that occur at a low rate could have been missed. Third, four different types of stent-grafts were used in our patients depending on availability, decreasing the complication sensitivity related to a specific device. Fourth, indications and underlying diseases for carotid stent-graft placement varied in our patient cohort. Finally, a control group is lacking. In conclusion, stent-grafts may be used successfully in selected cases for the treatment of carotid artery aneurysms, stenoses, and bleeding syndromes. The results of mid-term follow-up are encouraging, especially in patients without carotid blow-out syndrome, but results from long-term follow-up must be evaluated in future studies. References 1. Chuter TA. Branched and fenestrated stent grafts for endovascular repair of thoracic aortic aneurysms. J Vasc Surg 2006; 43(suppl A):111A–115A. 2. Jahnke T, Andresen R, Muller-Hulsbeck S, et al. Hemobahn stent-grafts for treatment of femoropopliteal arterial obstructions: midterm results of a prospective trial. J Vasc Interv Radiol 2003; 14:41–51. 3. Lesley WS, Chaloupka JC, Weigele JB, Mangla S, Dogar MA. Preliminary experience with endovascular reconstruction for the management of carotid blowout syndrome. AJNR Am J Neuroradiol 2003; 24:975–981. 4. Saatci I, Cekirge HS, Ozturk MH, et al. Treatment of internal carotid artery aneurysms with a covered stent: experience in 24 patients with mid-term follow-up results. AJNR Am J Neuroradiol 2004; 25:1742–1749. 5. Elsner M, uch-Schwelk W, Britten M, Walter DH, Schachinger V, Zeiher AM. Coronary stent grafts covered by a polytetrafluoroethylene membrane. Am J Cardiol 1999; 84:335–338. 6. Baltacioglu F, Cimsit NC, Cil B, Cekirge S, Ispir S. Endovascular stentgraft applications in latrogenic vascular injuries. Cardiovasc Intervent Radiol 2003; 26:434 – 439. 7. Schillinger M, Dick P, Wiest G, et al. Covered versus bare self-expanding stents for endovascular treatment of carotid artery stenosis: a stopped randomized trial. J Endovasc Ther 2006; 13:312–319.
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8. Layton KF, Kim YW, Hise JH. Use of covered stent grafts in the extracranial carotid artery: report of three patients with follow-up between 8 and 42 months. AJNR Am J Neuroradiol 2004; 25:1760 –1763. 9. Gralla J, Brekenfeld C, Schmidli J, Caversaccio M, Do DD, Schroth G. Internal carotid artery aneurysm with life-threatening hemorrhages in a pediatric patient: endovascular treatment options. J Endovasc Ther 2004; 11:734 – 738. 10. Martin ND, Carabasi RA, Bonn J, Lombardi J, DiMuzio P. Endovascular repair of carotid artery aneurysms following carotid endarterectomy. Ann Vasc Surg 2005; 19:913–916. 11. Bergeron P, Khanoyan P, Meunier JP, Graziani JN, Gay J. Long-term results of endovascular exclusion of extracranial internal carotid artery aneurysms and dissecting aneurysm. J Interv Cardiol 2004; 17:245–252. 12. Macdonald S, Gan J, McKay AJ, Edwards RD. Endovascular treatment of acute carotid blow-out syndrome. J Vasc Interv Radiol 2000; 11:1184 –1188. 13. Barr JD, Connors JJ, Sacks D, et al. Quality improvement guidelines for the performance of cervical carotid angioplasty and stent placement. J Vasc Interv Radiol 2003; 14:S321–S335. 14. Citardi MJ, Chaloupka JC, Son YH, Ariyan S, Sasaki CT. Management of carotid artery rupture by monitored endovascular therapeutic occlusion (1988 –1994). Laryngoscope 1995; 105: 1086 –1092. 15. Chaloupka JC, Putman CM, Citardi MJ, Ross DA, Sasaki CT. Endovascular therapy for the carotid blowout syndrome in head and neck surgical patients: diagnostic and managerial considerations. AJNR Am J Neuroradiol 1996; 17:843– 852. 16. Purdue GF, Pellegrini RV, Arena S. Aneurysms of the high internal carotid artery: a new approach. Surgery 1981; 89:268 –270. 17. Alexander MJ, Smith TP, Tucci DL. Treatment of an iatrogenic petrous carotid artery pseudoaneurysm with a Symbiot covered stent: technical case report. Neurosurgery 2002; 50:658 – 662. 18. Scavee V, De Wispelaere JF, Mormont E, Coulier B, Trigaux JP, Schoevaerdts JC. Pseudoaneurysm of the internal carotid artery: treatment with a covered stent. Cardiovasc Intervent Radiol 2001; 24:283–285. 19. Simionato F, Righi C, Melissano G, Rolli A, Chiesa R, Scotti G. Stent-graft treatment of a common carotid artery pseudoaneurysm. J Endovasc Ther 2000; 7:136 –140.
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20. Marotta TR, Buller C, Taylor D, Morris C, Zwimpfer T. Autologous veincovered stent repair of a cervical internal carotid artery pseudoaneurysm: technical case report. Neurosurgery 1998; 42:408 – 412. 21. Smith T, Alexander M, Enterline D. Delayed stenosis following placement
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of a polyethylene terephthalate endograft in the cervical carotid artery: report of three cases. J Neurosurg 2003; 98:421– 425. 22. Yavuz K, Geyik S, Pavcnik D, et al. Comparison of the endothelialization of small intestinal submucosa, Dacron, and expanded polytetrafluoroethylene
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suspended in the thoracoabdominal aorta in sheep. J Vasc Interv Radiol 2006; 17:873– 882. 23. Kwok PC, Cheung JY, Tang KW, Wong WK. Re: endovascular treatment of acute carotid blow-out syndrome. J Vasc Interv Radiol 2001; 12: 895– 896.
PURPOSE: To report the authors’ initial experience with carotid artery stent-grafts in a comparatively large patient series for the treatment of acute bleeding and impending rupture or the prevention of distal embolization. MATERIALS AND METHODS: This retrospective study was approved by the institutional review boards and performed according to HIPPA standards. Twenty-five patients were treated with 27 carotid artery stent-grafts (Gore Viabahn, n ⴝ 10; Bard Fluency, n ⴝ 9; polytetrafluoroethylene— covered Palmaz, n ⴝ 5; and Wallgraft, n ⴝ 3). Thirteen stent-grafts were placed in patients with carotid blow-out syndrome (including three patients with carotid-airway fistula), 12 in patients with either pseudoaneurysm (n ⴝ 9) or true aneurysm (n ⴝ 3), and two in patients with intractable high-grade bare stent restenosis. RESULTS: The technical success rate was 100% (27 of 27 cases). No acute procedural transient ischemic attacks or strokes occurred. Procedural dissections occurred in two of the 27 cases (7.4%). Short-term complications occurred in three of the 27 cases (11%) (repeat hemorrhage, n ⴝ 2; common carotid artery occlusion, n ⴝ 1). The overall patient mortality rate was 36% (nine of 25 patients, all with carotid blow-out syndrome). Six-month follow-up in 15 of the 16 living patients demonstrated widely patent stent-grafts. Two patients with pseudoaneurysm also demonstrated patent stents at 18- and 33-month follow-up. CONCLUSIONS: Stent-grafts may be useful in the treatment of carotid artery bleeding syndrome, aneurysm, and stenosis, with a high procedural success rate in selected cases. The results of mid-term follow-up are encouraging, but results of long-term follow-up must be evaluated in future studies. J Vasc Interv Radiol 2008; 19:31– 41 Abbreviations:
CCA ⫽ common carotid artery, FDA ⫽ Food and Drug Administration, ICA ⫽ internal carotid artery, PTFE ⫽ polytetrafluoroethylene
RECENTLY, covered stents or stentgrafts have become a more frequent alternative in the treatment of vascular diseases that could once only be treated with surgical intervention. At present, stent-grafts are successfully
From the Dotter Interventional Institute, Oregon Health and Sciences University, L-342, 3181 SW Sam Jackson Park Rd, Portland, OR 97201 (H.H., S.L.B., G.M.N., B.D.P.); and the Department of Angiography, Portland Veterans Administration Medical Center, Portland, OR (B.D.P.). Received March 12, 2007; final revision received August 7, 2007; accepted August 19, 2007. Address correspondence to B.D.P.; E-mail: [email protected] None of the authors have identified a conflict of interest. © SIR, 2008 DOI: 10.1016/j.jvir.2007.08.024
used for the treatment of aneurysm, pseudoaneurysm, vascular injury, and intractable intimal hyperplasia in various vascular beds (1– 6). It has been difficult to place stent-grafts in the carotid artery because of the risk of cerebral infarction resulting from acute dissection, occlusion, or embolism, which may be caused by the large device profile and size and lack of flexibility of delivery systems (3). Additional concerns include the presumed risk of latent occlusion from thrombus formation or intimal hyperplasia. As reported in a previous study (7), carotid stent-grafts had an advantage in lowering the cerebral embolization rate, but had an excessive incidence of in-stent restenosis. The use of stentgrafts in the treatment of carotid artery disease has been previously described
as anecdotal experiences in various case reports (8 –12), whereas we present data from a larger series of patients in whom this technique has been used, including results of mid-term angiographic and clinical follow-up. The purpose of this retrospective study was to evaluate our initial experience with stent-grafts in the carotid artery in a comparatively large patient series with vascular lesions requiring emergent or urgent treatment for acute bleeding or impending rupture or to prevent distal embolization.
MATERIALS AND METHODS Study Population This retrospective study was approved by the institutional review
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Summary of Results in 25 Patients Treated with the Placement of 27 Carotid Artery Stent-Grafts Patient No./ Age/Sex
Indication for Treatment
Location of Stent-Graft
Type of Stent-Graft
Comments
1/61/F
CBS
R CCA/ICA
PTFE Palmaz
2/86/F 3/75/M 4/67/F 5/62/F 6/33/M 7/87/F
CBS CBS CBS CBS CBS CBS CBS CBS
L CCA L CCA L CCA R CCA L CCA R CCA/ICA R CCA L ICA
PTFE Palmaz PTFE Palmaz PTFE Palmaz PTFE Palmaz Fluency Fluency Wallgraft Wallgraft
8/63/F 9/61/M
CBS Carotid-airway fistula
L CCA/ICA R CCA
Wallgraft Fluency
10/64/F 11/52/M 12/68/M 13/20/F
Carotid-airway fistula Carotid-airway fistula Pseudoaneurysm Pseudoaneurysm
Viabahn Viabahn Fluency Viabahn
14/67/M 15/53/M
Pseudoaneurysm Pseudoaneurysm dissection Pseudoaneurysm dissection Pseudoaneurysm stenosis Pseudoaneurysm stenosis Pseudoaneurysm stenosis Pseudoaneurysm dissection Aneurysm Aneurysm Aneurysm In-stent stenosis In-stent stenosis
and
R CCA R CCA L CCA/ICA L ICA (cervical/ petrous) R ICA R ICA (petrous)
Viabahn Fluency
R external carotid artery embolization for pseudoaneurysm L CCA dissection — L CCA embolization — — — Repeat hemorrhage and death L external carotid artery embolization for pseudoaneurysm — Surgical removal of stent-graft without pathologic findings after 10 d because of previous bypass surgery — Repeat hemorrhage — L external carotid artery embolization for bleeding — —
and
L ICA
Viabahn
L petrous ICA dissection
and
R ICA
Viabahn
—
and
L CCA
Fluency
—
and
L CCA
Fluency
—
and
R ICA
Viabahn
—
L ICA (petrous) L ICA (petrous) L CCA L CCA/ICA R ICA
Viabahn Viabahn Fluency Fluency Viabahn
— — — — —
16/44/F 17/47/M 18/63/F 19/67/F 20/57/M 21/55/M 22/74/M 23/65/M 24/65/M 25/80/M
Note.—CBS ⫽ carotid blow-out syndrome, HNC ⫽ head and neck cancer, L ⫽ left, R ⫽ right * Clinical follow-up as of January 2007.
boards and was performed according to Health Insurance Portability and Accountability Act standards. We reviewed the images and medical records from all patients who were treated with stent-grafts in the carotid vasculature from March 1998 to November 2006. Twenty-seven stentgrafts were placed in the common and internal carotid arteries in 25 patients (11 women, 14 men). The mean patient age (⫾standard deviation) was 61 years ⫾ 16.3 (range, 20 – 87 years). Written, informed consent for placement was obtained from all patients. Data for this study were obtained from imaging studies and medical
records. Data were collected and analyzed in terms of overall outcomes and, in addition, categorized according to the indication for stent placement. Indications Twenty-seven stent-grafts were placed in 27 procedures and 25 patients. All cases were emergent or urgent in nature. Thirteen stent-grafts were placed in patients with carotid blow-out syndrome, including three patients with carotid-airway fistulas. These patients were terminally ill with progressive head and neck cancer and had under-
gone multiple surgeries and irradiation. These patients had sentinel hemorrhage or profuse, poorly controlled hemorrhage. They were not surgical candidates because they had an incomplete circle of Willis or contralateral carotid artery occlusion. Three stent-grafts were placed in one patient with bilateral disease. Twelve more patients with either pseudoaneurysm (n ⫽ 9) or true aneurysm (n ⫽ 3) of their common carotid artery (CCA) or internal carotid artery (ICA) were treated to prevent impending rupture. Two other patients had developed intractable high-grade stenoses due to intimal hyperplasia within previously
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Angio Longest Follow-up (mo)
Outcome at Follow-up
Origin and Extension of Disease
Time between Death and Last Procedure
1
Occlusion of R CCA
HNC, extended disease
1 y, 2 mo
Death (primary disease)
HNC, extended disease HNC, extended disease
3 mo 1 y, 6 mo
Death (primary disease) Death (primary disease)
HNC, HNC, HNC, HNC,
5 mo 48 h 6 mo
Death (primary disease) Clinically well at 18 mo Death (procedure related) Death (primary disease)
10 mo 5 mo
Death (primary disease) Death (primary disease)
4
Patent
6
Patent
extended extended extended extended
disease disease disease disease
HNC, extended disease HNC, extended disease
6
Patent
Cause of Death or Results at Clinical Follow-up*
Pending 6
Patent
HNC, extended disease HNC, extended disease Trauma Trauma
6 and 33 6
Patent Patent
Trauma Trauma
Clinically well at 36 mo Clinically well at 24 mo
6
Patent
Atheromatous disease
Clinically well at 40 mo
6 and 18
Patent
Spontaneous
Clinically well at 30 mo
6
Patent
HNC, irradiation
Clinically well at 30 mo
6
Patent
Carotid endarterectomy
Clinically well at 23 mo
6
Patent
Atheromatous disease
Clinically well at 16 mo
6 6 6 6 6
Patent Patent Patent Patent Patent
Atheromatous Atheromatous Atheromatous Atheromatous Atheromatous
Clinically well at 41 Lost to follow-up at Lost to follow-up at Clinically well at 25 Clinically well at 45
placed bare carotid stents, which had failed previous interventions. These patients were then treated with stentgrafts to prevent distal embolism or stroke. Technique Stent placement was performed with the patient under moderate sedation by using intravenous administration of fentanyl and midazolam. Blood pressure, electrocardiographic parameters, arterial oxygen saturation, and respiratory rate were continuously monitored. With use of a percutaneous transfemoral approach, initial di-
24 h
disease disease disease disease disease
agnostic arteriography of the carotid and intracranial vascular anatomy was performed by using a high-resolution biplane, digital subtraction angiography unit (Philips Medical Systems, Bothell, Wash). Stent-graft placement required the placement of large 8.5– 12-F, 80-cm-long delivery sheaths (Cook, Bloomington, Ind) into the common or internal carotid artery. This was generally performed over a stiff 260-cmlong exchange-length guide wire (Amplatz Super Stiff; Boston Scientific, Natick, Mass). Stent-grafts were then deployed across the involved arterial segments (CCA, n ⫽ 12; CCA and ICA, n ⫽ 5; ICA, n ⫽ 10 [including four
Lost to follow-up at 18 mo Death (procedural related) Clinically well at 17 mo Clinically well at 30 mo
mo 39 mo 15 mo mo mo
in the petrous ICA]) by using biplane fluoroscopic angiography with road map guidance. The choice of a particular stent was determined by both the availability and the diameter and length of the target lesion. Five homemade polytetrafluoroethylene (PTFE)– covered Palmaz stents (Cordis, Miami, Fla) were used on a humanitarian basis before receiving U.S. Food and Drug Administration (FDA) approval. The following FDA-approved stent-grafts were used: 10 Viabahn stents (Gore, Newark, Del), nine Fluency stents (Bard, Tempe, Ariz), and three Wallgrafts (Boston Scientific, Minneapolis, Minn). In general, cerebral protection de-
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vices were not usually used in patients with acute bleeding or aneurysmal disease. After receiving FDA approval, distal filter protection devices were used in four patients with lesions associated with stenotic lesions. The Emboshield cerebral protection device (Abbott Laboratories, Abbott Park, Ill) was used in two different patients with complex lesions, that is, high-grade stenoses associated with pseudoaneurysms caused by previous dissection. The Accunet device (Guidant, St Paul, Minn) and the EPI device (Boston Scientific) were used in the two patients who were treated for in-stent restenosis of their carotid stents. After placement of the stent-graft, it was dilated to the normal artery size by using angioplasty balloon catheters, being careful not to dilate outside the confines of the stent-graft. At the conclusion of the procedure, control cerebral and carotid angiograms were obtained for all patients. Heparin was intravenously administered depending on the situation and was not used in patients who were acutely bleeding. Heparin was administered in 15 of the 27 procedures (56%) in patients with more stable lesions in a manner to elevate the activated clotting time to 250 seconds or greater. All patients received 75 mg of clopidogrel orally every day (Plavix; Bristol-Myers Squibb/Sanofi Pharmaceuticals Partnership, New York, NY) for 6 months and 325 mg of aspirin orally every day. Additional external carotid artery embolization was performed in three patients by using Nester coils (Cook) and/or GDC coils (Target Therapeutics, Fremont, Calif). Complications and Follow-up Technical success and procedural complications were collected and recorded. Neurologic complications were categorized as minor and major per SIR reporting standards (13). Complications at follow-up were categorized as shortterm complications if they occurred within 30 days or less after stent-graft placement and as mid-term complications if they occurred more than 30 days after stent-graft placement. Patients were followed up with both clinical and angiographic examinations. Repeat hemorrhage was diagnosed clinically, with computed tomography and/or ultrasonography, or with angiography.
Statistics Data were entered into a worksheet (Excel 2003; Microsoft, Redmond, Wash). Descriptive and summary statistics were calculated (GraphPad InStat V3.0 for Windows; GraphPad, San Diego, Calif) and tables created.
RESULTS Overall Outcomes Results are summarized in the Table. All 27 carotid stent-grafts were placed successfully in 25 patients (Figs 1 and 2). The technical success rate was 100% (27 of 27 cases). No minor or major neurologic complications occurred. Procedural complications occurred in two of the 27 cases (7.4%). In one patient treated for carotid blowout syndrome, a dissection of the proximal CCA was caused by introduction of an 8.5-F sheath, which was subsequently treated with two bare self-expanding nitinol stents (Smart; Cordis). At follow-up, there was normal luminal integrity with only slight filling of the false lumen of the dissection. In a patient with a pseudoaneurysm, the tip of a 0.035-inch guide wire caused a dissection of the petrous ICA, which was subsequently treated with a bare stent (Precise; Cordis). At control angiography, there was excellent flow and no substantial residual dissection. Both patients did well without ischemic or embolic symptoms. Short-term complications occurred in four of the 27 cases (15%). One occlusion of the right CCA occurred within 30 days of placement of a PTFE-covered Palmaz stent for carotid blow-out syndrome (Fig 3). One early rupture with repeat hemorrhage occurred after placement of a Viabahn stent-graft for the treatment of carotid blow-out syndrome with carotid-airway fistula and eventual patient death. This patient had received large amounts of transfused blood products during transportation to our institution for treatment. The stent-graft procedure was uncomplicated and angiography demonstrated the correct placement of the Viabahn, with a patent lumen, excellent blood flow, and no evidence of extravasation. After initial complete cessation of hemorrhage, there was slow repeat bleeding, which built to eventual substantial hemorrhage. Re-
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peat angiography demonstrated no evidence of contrast medium extravasation and the correct placement of the stent. The patient’s activated partial thromboplastin time at this point was 178 seconds, and he was most likely in massive disseminated intravascular coagulopathy secondary to enormous blood loss. The patient was urgently transferred to the operating room for surgical intervention and died within 24 hours. This patient had undergone total laryngectomy with an interposition flap 2 weeks earlier. He was admitted from the emergency department with a flap infection. In the hospital, he had a “Herald bleed” followed by a massive hemorrhage. A massive transfusion protocol was begun, and the patient received more than 20 units of blood products. He was taken to angiography, where bleeding was first controlled with placement of a balloon and then a stent-graft. Because of disseminated intravascular coagulation from the massive transfusion, the infected flap continued to ooze from the margins; however, the massive bleeding was controlled. The patient was taken to the operating room to débride the flap, control the ooze from the margins of the failing surgical flap. In the operating room, the patient had respiratory arrest, primarily due to pulmonary edema and “stiff lungs” from the massive resuscitation efforts and fluid. He could not be revived. At autopsy, the stent-graft could be seen through a large rent or hole in the right carotid artery, in good position, surrounded by necrotic and purulent material. Three stent-grafts were placed in the same patient for bilateral carotid blow-out syndrome. After successful placement of a PTFE-covered Palmaz stent in the left CCA for acute bleeding, repeat hemorrhage occurred 9 days later. Repeat angiography demonstrated slight flow around the balloon-expandable device, which was then expanded from 6 to 8 mm in diameter with a balloon angioplasty catheter. This further expansion of the device resulted in device rupture and massive extravasation. A second PTFE-covered Palmaz stent was placed inside of the first, resulting in control of extravasation with excellent flow. However, after discussion with the referring ear, nose, and throat surgeons and due to the uncertain durability of the new “homemade” device, this device was embolized 1 day later to provide definitive
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Figure 1. Images in a 63-year-old woman (patient no. 8) with laryngeal and tongue cancer. A vein bypass graft was recently placed in her left carotid artery. The left external carotid artery had been previously occluded. She developed massive hemoptysis and was referred for angiography. (a) Angiogram of the left CCA (a-p) demonstrates occlusion of the external carotid artery. A vein patch graft arises from the distal CCA up to the ICA at the level of the lower portion of the jaw (arrowheads). There is a pseudoaneurysm of the distal graft anastomois (arrow). There is no active extravasation beyond the pseudoaneurysm at this point. (b) A 6 ⫻ 50-mm Wallgraft was deployed and dilated by using a 5 ⫻ 40-mm-long vascular balloon. (c) Left carotid angiogram (a-p) obtained after stent-graft deployment demonstrates diminishing flow to the wall of the graft into the pseudoaneurysm. There is continued mild filling of the pseudoaneurysm through the porous Dacron graft material (arrow) because the patient was receiving heparin. (d) Follow-up left carotid angiogram (a-p) obtained the next day demonstrates complete patency of the left CCA, ICA, and bypass graft, with no filling of the pseudoaneurysm. No irregularities, intraluminal filling defects, or other abnormalities are noted. There is excellent flow through the stent-graft.
control of the arterial bleeding. Five months later, another PTFE-covered Palmaz stent was successfully placed in the same patient for contralateral carotid blow-out syndrome. In another patient treated for acute bleeding due to carotid blow-out syndrome, bleeding recurred after it was initially controlled with placement of a Wallgraft in the CCA. This repeat bleeding occurred 48 hours after treatment and resulted in the patient’s death. At autopsy, there was evidence that the tumor had extended cephalad beyond the CCA and into the ICA, to a new or additional bleeding site beyond the distal aspect of the Wallgraft. The initial placement of the Wallgraft was not extended into the ICA due to vessel tortousity and fear of vessel perforation or embolic complication. The patient died 48 hours later. In an “intend-to-treat” analysis, two patients with carotid blow-out syndrome—this patient with the Wallgraft and the patient with the Viabahn mentioned ear-
lier— died related to the procedure, for a procedural-related mortality rate of 8%. The overall patient mortality rate was 36% (nine of 25 patients, all with carotid blow-out syndrome). In one patient with carotid blowout syndrome, surgical removal of the stent-graft was performed 10 days after stent placement because the patient had subsequently undergone a carotid-subclavian bypass and endovascular CCA occlusion to avoid potential stent-graft infection due to a coexistent fistula.
drome and/or airway fistula). Two patients treated for a pseudoaneurysm demonstrated a patent stent at longterm follow-up 18 (Fig 4) and 33 (Fig 5) months after stent-graft placement, respectively. In one patient treated for pseudoaneurysm, angiographic follow-up is still pending, but the patient is alive and asymptomatic at 18 months. The average clinical follow-up time was 28 months (range, 15– 45 months). Three patients were lost to follow-up at 15, 18, and 39 months, respectively.
Follow-up
DISCUSSION
The overall patient mortality rate was 36% (nine of 25 patients, all with carotid blow-out syndrome). At 6-month angiographic follow-up, widely patent stent-grafts were found in 15 patients (11 with aneurysm and/or pseudoaneurysm, two with in-stent restenosis, and two with carotid blow-out syn-
This study represents a rather large experience in the use of stent-grafts for the treatment of patients with bleeding or aneurysmal diseases of the carotid vasculature and demonstrates that stent-grafts can be used as an alternative treatment in a heterogeneous population of patients who would be
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Figure 2. Images in an 80-year-old man (patient no. 25) with right cervical ICA stenosis. (a) Digital subtraction angiogram (lateral projection) of the right carotid artery demonstrates proximal right ICA stenosis (arrow). (b) Right carotid artery angiogram (lateral projection) demonstrates cervical ICA stenosis, which was initially treated with a 10 ⫻ 38-mm Dynalink stent (Abbott Laboratories, Abbott Park, Ill) 5 years earlier, with a good initial result. (c) Right carotid digital subtraction angiogram (lateral projection) obtained 4 years later, in 2005, shows the asymptomatic right ICA in-stent stenosis of 80% (arrow). A stent had been placed in the left CCA (arrowhead) 3 years earlier for a 60% stenosis caused by an ulcerated plaque at the origin of the left ICA. (d) Right carotid angiogram (lateral projection) obtained after angioplasty of the right ICA demonstrates irregular residual stenosis greater than 50% (arrow). (e) A 6 ⫻ 25-mm Viabahn stent-graft was placed within the previously placed Dynalink stent, and angioplasty was performed with a 5.5 ⫻ 20-mm balloon. (f) Right carotid angiogram obtained in the lateral projection after stent-graft placement demonstrates wide patency without abnormality.
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Figure 3. Images in a 61-year-old woman (patient no. 1) with squamous cell carcinoma of the piriform sinus, soft palate, and tongue who underwent surgery and radiation therapy. The woman also has a large orocutaneous fistula. The patient presented to the emergency room with profuse bleeding through her fistula. (a) Angiogram of the right CCA (a-p) demonstrates a pseudoaneurysm (arrow) with early filling extending about the region of the bifurcation in the proximal segment of the right external carotid artery. The pseudoaneurysm fills from the region of the external carotid artery origin before its previous embolization site. There is acute bleeding with contrast medium extravasation (arrowheads). (b) A P424 Palmaz stent-graft covered with thin-walled Gore-Tex was placed with preservation of antegrade flow through the parent vessel and complete closure of the pseudoaneurysm. Right CCA angiogram (a-p) demonstrates restoration of the vessel luminal diameter at the region of the stent approximating the size of the vessel lumen just distal to the stent (arrow). The acute bleeding was stopped. (c) Follow-up CT angiogram (axial projection) obtained 1 month later demonstrates occlusion of the stent-graft (arrow) in the right ICA. There is no external compression of the stent-graft. The patient was asymptomatic.
at high risk for stroke or death with conventional surgical repair. In most patients who presented with acute bleeding, bleeding was controlled with stent-graft placement, either to allow time for elective surgical repair or as a final procedure in these patients with terminal disease. These are difficult patients to control surgically, and our results compare favorably with historic surgical controls and results in this subset of patients with carotid blow-out syndrome or direct carotid artery to airway fistula (14). Carotid blow-out syndrome is a term that has commonly been used to describe cases of rupture of the extracranial carotid artery or its branches. It is a usually regarded as a rare but life-threatening complication of head and neck cancer therapy (12). Various etiologic factors relating to surgery and adjuvant therapy have been implicated. Besides surgical ligation and
permanent balloon occlusion, treatment of carotid blow-out syndrome with stent-grafts has been previously described as anecdotal case reports (3,12). In our study, the mortality rate for patients with carotid blow-out syndrome after endovascular treatment with stent-grafts was 82% (nine of 11). In the literature, the reported mortality rate for this condition ranges from 9% to 100% after various treatment options (14). The mortality rate obtained by Lesley et al (3) was lower than that in our study, but this is due to a different patient cohort. Lesley et al classified patients with carotid blow-out syndrome into three groups. Although most patients in their study were group I or II patients, most of the patients in our study are group III patients. These are patients with extended disease, sentinel hemorrhage, or profuse, poorly controlled hemor-
rhage. The comparison of different subsets of patients with carotid blowout syndrome, however, was not the subject of our study. In our study, repeat hemorrhage after stent-graft placement occurred in three of 13 cases of carotid blow-out syndrome (23%), whereas one patient was successfully treated with another covered stent-graft and two patients eventually died. Before the introduction of covered stent-grafts, emergency surgical ligation or permanent balloon occlusion had been the only therapeutic procedures available for carotid blow-out syndrome, despite the well-documented risk of cerebral ischemia (15). In the study by Chaloupka et al (15), major neurologic complications after surgical ligation of the carotid artery were observed in approximately 60% of patients. In our study, no neurologic complications were observed af-
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Figure 4. Images in a 47-year-old man (patient no. 17) with a right-sided ICA pseudoaneurysm. (a) Right carotid angiogram (a-p) demonstrates an 11 ⫻ 15-mm aneurysm that projects medially and anteriorly to the ICA with a 5-mm neck (arrow). The cervical ICA has persistent stenosis (arrowhead), which measures up to 70% luminal diameter and at least 3 cm in length at the level of the aneurysm. Flow distal to the stenosis in the intracranial ICA is slow but antegrade. (b) A 6 ⫻ 50-mm Viabahn stent-graft was placed in the right ICA. (c) Digital subtraction angiogram (a-p) of the right carotid artery after stent-graft placement. There is a small amount of spasm proximal to the stent-graft (arrow), which resolved over time. A flap is also visible. (d) Digital subtraction angiogram (a-p) of the right carotid artery 18-months after stent-graft placement. The graft is widely patent and without abnormality.
Figure 5. Images in a 67-year-old man (patient no. 14) with a pseudoaneurysm and bleeding of the right ICA caused by surgery (anterior diskectomy). The pseudoaneurysm caused airway compression. (a) Right carotid angiogram (lateral projection) with landmarks demonstrates a right ICA pseudoaneurysm. (b) A 6 ⫻ 25-mm Viabahn stent-graft was placed and the aneurysm successfully excluded. (c) Follow-up image obtained 33 months later demonstrates a widely patent stent-graft. The patient is clinically well at 36 months.
ter endovascular treatment with covered stent-grafts. This is supported by the results of the study by Lesley et al (3), who reported no major stroke in their series of 16 carotid blow-out
cases treated with stents, including two covered stent-grafts. These results imply that stent-grafts may represent an excellent alternative treatment for patients with poor collateral flow who
are at increased risk for stroke with ligation or permanent occlusion. Patients with pseudoaneurysms, true aneurysms, or in-stent restenosis represent a group of patients requiring
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urgent, but less emergent therapy. Many of these patients had either contralateral carotid artery occlusions or lesions located in areas not amenable to conventional surgery, placing them at high risk for complications. All of these patients were treated without transient ischemic episodes or stroke or other major complications. We have records from both clinical and angiographic follow-up in most of our patients, from 6 months to 39 months. In all instances, the stent-grafts have remained patent and patients asymptomatic, establishing a level of durability to the procedure despite the use of different types of stent-grafts. Before the development of endovascular treatment, surgery was the only treatment option for symptomatic or complicated aneurysms of the carotid artery, which may lead to embolic complications, nerve compression, or rupture. In aneurysms of the distal extracranial ICA, surgery is often challenging and may be disabling (16). After surgery, a stroke rate of 5%–15% and a mortality rate of 2%– 4% have been reported (11). Covered stents or stent-grafts are a promising treatment option, especially for distally located aneurysms and dissecting aneurysms. In our study, 12 patients with aneurysms were successfully treated with stent-grafts. No major stroke occurred and no patient died. These 12 procedures were complicated only by one asymptomatic carotid dissection caused by a guide wire that was successfully treated with a bare stent. The use of stent-grafts for the treatment of a carotid aneurysm or pseudoaneurysm has been reported as anecdotal experiences or small patient series (17). Martin et al (10) reported on a case of successful treatment of a carotid artery aneurysm with a stentgraft after carotid endarterectomy. Gralla et al (9) described the use of a covered stent to treat an ICA aneurysm with life-threatening hemorrhages in a pediatric patient. Scavee et al (18) successfully obliterated a pseudoaneurysm with preservation of the carotid artery by using a stent-graft. Simionato et al (19) successfully treated a posttraumatic wide-necked carotid aneurysm with a stent-graft. Layton et al (8) described one patient with neurofibromatosis and ruptured pseudoaneurysm from tumor invasion
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and another with traumatic pseudoaneurysm, both of whom were successfully treated by using two stent-grafts each. A small series of endovascular treatment with stent-grafts of five extracranial ICA aneurysms in four patients was reported by Bergeron et al (11). All stent-grafts remained patent and no adverse events were observed at follow-up after more than 1 year. One early endoleak was observed and treated with covered stent extension. In our study, two patients were treated for in-stent restenosis with a covered stent-graft. No adverse events occurred and follow-up demonstrated excellent results. Layton et al (8) reported one case of intractable intimal hyperplasia causing in-stent restenosis despite multiple treatments with conventional angioplasty. A stent-graft was placed across the focal stenosis within the previously placed wall stent. When recurrent high-grade stenosis occurred within the portion of the Wallstent that was not covered with the stent-graft, additional angioplasty and intraarterial brachytherapy were successfully performed. Intimal hyperplasia, however, did not recur in the portion of the carotid artery treated with the covered stent-graft. When this case series began in 1998, no FDA-approved commercial devices were available for use. Our earliest cases were performed with balloonexpandable Palmaz stents covered with pre-expanded PTFE. These devices were used on a humanitarian basis to prevent potentially life-threatening bleeding, all in patients with head and neck cancers. In the short-term, these devices proved to work quite well, preventing bleeding without dislodgement, migration, or compression. Because these patients had a limited life expectancy, the long-term durability of these devices was not tested. Marotta et al (20) reported on the placement of an autologous veincovered Palmaz stent in a patient with carotid blow-out syndrome, resulting in immediate exclusion of an ICA pseudoaneurysm. Results of 1-month follow-up helped confirm the successful exclusion of the pseudoaneurysm and carotid patency without stenosis. This technique may help prevent stent-related thromboembolism and recurrent carotid blow-out syndrome but must be investigated in further studies.
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The first commercially available FDA-approved device was the Boston Scientific Wallgraft. This self-expanding device is made of woven stainless steel with a porous Dacron covering. Although it still requires a large delivery sheath (larger than 9 F), because of its longitudinal flexibility the deliverability of this device was better than that of our homemade device. Once deployed, this flexibility also enabled better conformability to arterial walls, especially those with tortuous anatomy. The biggest disadvantage of the device, however, was the porous Dacron covering. Although Dacron is a commonly used as a vascular graft material, in this setting, the Dacron is “pre-clotted” with the patient’s blood to prevent leakage through the fabric. This is not possible when used as the covering of the Wallgraft, and the porosity made it unsuitable for use in an acute bleeding situation such as carotid blow-out syndrome because blood will simply pour through the fabric, not clotting in a timely fashion to prevent stroke or exsanguination (21). Furthermore, when used as an endograft in the peripheral circulation, it is known to incite an inflammatory response, which may lead to early vessel occlusion (22). The flexible and self-expanding characteristics of the Wallgraft were an improvement over our balloon-expandable device, but the porosity and inflammatory nature of the covering made it unsuitable and we used it only when no other device was available. The next two commercially available stent-grafts were the Gore Viabahn (which received FDA approval for the treatment of tracheobronchial strictures on April 25, 2005) and the Bard Fluency (which received FDA approval for the treatment of tracheobronchial strictures on June 19, 2003). Both of these devices are made of selfexpanding nitinol covered with PTFE. Although it still requires large delivery sheaths, both the flexibility and conformability are improved compared to that of the Wallgraft, and the PTFE covering is substantially nonadhesive to flowing blood. The Gore device was the first of these two to become available in a long delivery sheath (110 cm) necessary for placement in the carotid artery. It requires an 8 –12-F sheath for the diameters used in the carotid circulation. The
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Bard Fluency device recently became available in long delivery lengths (117 cm) and requires a 9-F sheath in diameters of 6 –10 mm. Although the delivery mechanisms of the two devices differ, we now use these two devices nearly interchangeably. Of interest, Gore is now offering the Viabahn with a lower profile delivery system through a 7-F sheath for 6-mm stentgrafts and an 8-F sheath for 7– 8-mm stent-grafts. In the present study, self-expanding stents were used preferentially over balloon-mounted stents because of a variety of technical and biomechanical factors. Self-expanding stents more easily accommodate varying diameters of the carotid artery, especially at the transition from the CCA to ICA. Self-expanding stents are more forgiving when determining the necessary diameter and demonstrate superior flexibility in conforming to tortuous segments of the carotid segment (3). In addition, a self-expanding stent is safer than a balloon-mounted stent because of potential arterial injury resulting from high balloon inflation pressures needed for stent deployment. This is particularly important in patients with carotid blow-out syndrome because the target arterial segment is already weakened by the underlying disease (14,15). Kwok et al (23) reported on a case of carotid blow-out syndrome treated with a balloon-expandable covered stent-graft (Jomed, Helsingborg, Sweden) that offered no protection to high pressure. Extravasation at both ends of the stent with persistent transoral hemorrhage occurred and eventually required endovascular occlusion of the CCA. The placement of carotid stentgrafts requires a variety of favorable anatomic and pathophysiologic factors such as common femoral and iliac arterial anatomy that will permit the placement of a large-caliber (9 –12-F) sheath, simple curvature of the aortic arch, relatively straight carotid and brachiocephalic arteries, and the lack of coexistent atherosclerotic or postradiation stenosis. Therefore, more widespread use of self-expanding covered stent-grafts will require technology improvements, including lower profile delivery systems, increased overall flexibility, and enhanced deliverability. There are several limitations of this
study. First, the study is retrospective in nature and therefore not controlled for selection bias, detection of events, and data collection. Second, although 27 stent-grafts were placed, complications that occur at a low rate could have been missed. Third, four different types of stent-grafts were used in our patients depending on availability, decreasing the complication sensitivity related to a specific device. Fourth, indications and underlying diseases for carotid stent-graft placement varied in our patient cohort. Finally, a control group is lacking. In conclusion, stent-grafts may be used successfully in selected cases for the treatment of carotid artery aneurysms, stenoses, and bleeding syndromes. The results of mid-term follow-up are encouraging, especially in patients without carotid blow-out syndrome, but results from long-term follow-up must be evaluated in future studies. References 1. Chuter TA. Branched and fenestrated stent grafts for endovascular repair of thoracic aortic aneurysms. J Vasc Surg 2006; 43(suppl A):111A–115A. 2. Jahnke T, Andresen R, Muller-Hulsbeck S, et al. Hemobahn stent-grafts for treatment of femoropopliteal arterial obstructions: midterm results of a prospective trial. J Vasc Interv Radiol 2003; 14:41–51. 3. Lesley WS, Chaloupka JC, Weigele JB, Mangla S, Dogar MA. Preliminary experience with endovascular reconstruction for the management of carotid blowout syndrome. AJNR Am J Neuroradiol 2003; 24:975–981. 4. Saatci I, Cekirge HS, Ozturk MH, et al. Treatment of internal carotid artery aneurysms with a covered stent: experience in 24 patients with mid-term follow-up results. AJNR Am J Neuroradiol 2004; 25:1742–1749. 5. Elsner M, uch-Schwelk W, Britten M, Walter DH, Schachinger V, Zeiher AM. Coronary stent grafts covered by a polytetrafluoroethylene membrane. Am J Cardiol 1999; 84:335–338. 6. Baltacioglu F, Cimsit NC, Cil B, Cekirge S, Ispir S. Endovascular stentgraft applications in latrogenic vascular injuries. Cardiovasc Intervent Radiol 2003; 26:434 – 439. 7. Schillinger M, Dick P, Wiest G, et al. Covered versus bare self-expanding stents for endovascular treatment of carotid artery stenosis: a stopped randomized trial. J Endovasc Ther 2006; 13:312–319.
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8. Layton KF, Kim YW, Hise JH. Use of covered stent grafts in the extracranial carotid artery: report of three patients with follow-up between 8 and 42 months. AJNR Am J Neuroradiol 2004; 25:1760 –1763. 9. Gralla J, Brekenfeld C, Schmidli J, Caversaccio M, Do DD, Schroth G. Internal carotid artery aneurysm with life-threatening hemorrhages in a pediatric patient: endovascular treatment options. J Endovasc Ther 2004; 11:734 – 738. 10. Martin ND, Carabasi RA, Bonn J, Lombardi J, DiMuzio P. Endovascular repair of carotid artery aneurysms following carotid endarterectomy. Ann Vasc Surg 2005; 19:913–916. 11. Bergeron P, Khanoyan P, Meunier JP, Graziani JN, Gay J. Long-term results of endovascular exclusion of extracranial internal carotid artery aneurysms and dissecting aneurysm. J Interv Cardiol 2004; 17:245–252. 12. Macdonald S, Gan J, McKay AJ, Edwards RD. Endovascular treatment of acute carotid blow-out syndrome. J Vasc Interv Radiol 2000; 11:1184 –1188. 13. Barr JD, Connors JJ, Sacks D, et al. Quality improvement guidelines for the performance of cervical carotid angioplasty and stent placement. J Vasc Interv Radiol 2003; 14:S321–S335. 14. Citardi MJ, Chaloupka JC, Son YH, Ariyan S, Sasaki CT. Management of carotid artery rupture by monitored endovascular therapeutic occlusion (1988 –1994). Laryngoscope 1995; 105: 1086 –1092. 15. Chaloupka JC, Putman CM, Citardi MJ, Ross DA, Sasaki CT. Endovascular therapy for the carotid blowout syndrome in head and neck surgical patients: diagnostic and managerial considerations. AJNR Am J Neuroradiol 1996; 17:843– 852. 16. Purdue GF, Pellegrini RV, Arena S. Aneurysms of the high internal carotid artery: a new approach. Surgery 1981; 89:268 –270. 17. Alexander MJ, Smith TP, Tucci DL. Treatment of an iatrogenic petrous carotid artery pseudoaneurysm with a Symbiot covered stent: technical case report. Neurosurgery 2002; 50:658 – 662. 18. Scavee V, De Wispelaere JF, Mormont E, Coulier B, Trigaux JP, Schoevaerdts JC. Pseudoaneurysm of the internal carotid artery: treatment with a covered stent. Cardiovasc Intervent Radiol 2001; 24:283–285. 19. Simionato F, Righi C, Melissano G, Rolli A, Chiesa R, Scotti G. Stent-graft treatment of a common carotid artery pseudoaneurysm. J Endovasc Ther 2000; 7:136 –140.
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20. Marotta TR, Buller C, Taylor D, Morris C, Zwimpfer T. Autologous veincovered stent repair of a cervical internal carotid artery pseudoaneurysm: technical case report. Neurosurgery 1998; 42:408 – 412. 21. Smith T, Alexander M, Enterline D. Delayed stenosis following placement
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of a polyethylene terephthalate endograft in the cervical carotid artery: report of three cases. J Neurosurg 2003; 98:421– 425. 22. Yavuz K, Geyik S, Pavcnik D, et al. Comparison of the endothelialization of small intestinal submucosa, Dacron, and expanded polytetrafluoroethylene
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suspended in the thoracoabdominal aorta in sheep. J Vasc Interv Radiol 2006; 17:873– 882. 23. Kwok PC, Cheung JY, Tang KW, Wong WK. Re: endovascular treatment of acute carotid blow-out syndrome. J Vasc Interv Radiol 2001; 12: 895– 896.