Cutting Balloon Angioplasty to Treat Carotid In-Stent Restenosis

ABSTRACT: We describe a case of carotid artery restenosis following carotid artery stenting for treatment of post-endarterectomy stenosis. The goal is to highlight the risk of recurrent restenosis following endarterectomy. In this case report, we describe the use of cutting balloon therapy as a reasonable alternative to repeat surgical revascularization.

Key words: arteriosclerosis, cerebrovascular disorders, endarterectomy

With the recent presentation of the SAPPHIRE trial¹ favoring carotid stenting with protection compared to carotid endarterectomy in high-risk patients, the number of carotid stenting procedures is expected to increase. As with coronary artery stenting, restenosis after stenting is a potential late complication of this procedure. The injury and subsequent inflammatory response to the carotid vessel wall caused by angioplasty and stenting are thought to be responsible for the restenosis. In this report, we identify a case of in-stent restenosis and propose cutting balloon percutaneous intervention as a treatment option for this complication. Case Report: A 70-year-old man with a history of hypertension, hyperlipidemia and peripheral vascular disease underwent carotid endarterectomy of the right internal carotid in July of 1999. He remained asymptomatic and upon routine surveillance in February of 2002 was found to have restenosis. Ultrasound interrogation at that time revealed a peak systolic velocity of 574 cm/second, an end diastolic velocity of 203 cm/second and an internal carotid artery/common carotid artery (ICA/CCA) ratio of 4.12, correlating to an 80–99% stenosis (Figure 1). He had patent antegrade vertebral arteries bilaterally. A quantitative angiography confirmed a 90% stenosis just distal to the carotid bifurcation (Figure 2). Using the Angioguard emboli protection device, the lesion was percutaneously intervened by first predilating with a 4.0 x 20 mm Crossail (Guidant Corporation, Temecula, California) inflated to 6 atmospheres (atm) for 30 seconds, followed by placement of an 8.0 x 40 mm Precise stent (Cordis Corporation, Miami, Florida). The stent was then post-dilated with a 5.5 x 20 mm Viatrac balloon (Guidant Corporation) inflated to 10 atm for 30 seconds, resulting in less than 10% residual stenosis (Figure 3). The patient tolerated the procedure well, with no periprocedural complications. However, carotid ultrasound 6 months later revealed in-stent restenosis with a peak systolic velocity of 378 cm/second and an end diastolic velocity of 113 cm/second, correlating to a stenosis of 60–79% (Figure 4). The ICA/CCA ratio was 4.27 and again both vertebral arteries were patent with antegrade flow. The patient was taken back to the cath lab, where quantitative angiography confirmed in-stent restenosis of 85% (Figure 5). After pretreating with heparin to achieve an activated clotting time of 280 seconds, a 6 mm Angioguard device was positioned in the distal internal carotid. Then a 4.0 x 15 mm Cutting Balloon (CB; Boston Scientific/Scimed, Inc., Maple Grove, Minnesota) was positioned in the center of the stenosis and inflated to 10 atm. This resulted in a reduction of the stenosis to approximately 20%, with a persistent “waist” that was resistant to repeated inflation (Figure 6). Therefore, a 5.0 x 15 mm NC monorail noncompliant balloon (Cordis Corporation) was inserted and inflated to 20 atm for 30 seconds. Finally, a 6.0 x 15 mm Diamond balloon (Boston Scientific/Scimed, Inc.) was positioned across the residual stenosis and inflated to 15 atm for 30 seconds, resulting in a residual stenosis of Discussion. Stenosis following endarterectomy is a resistant lesion to plain old balloon angioplasty (POBA) due to the excessive scarring caused by surgery.² In this case, carotid stenosis recurred following percutaneous stenting, thus creating a dilemma for subsequent treatment. We describe the successful treatment of a carotid in-stent restenosis with a CB. To our knowledge, no such work has been published on the use of CBs for the treatment of in-stent restenosis of a carotid lesion. With the recent report on the safety and efficacy of percutaneous carotid stenting compared to carotid endarterectomy in high-risk patients in the SAPPHIRE¹ trial, it is very likely that the number of carotid stenting procedures will increase. In-stent restenosis (ISR) is a rare complication of this procedure, but does occur in up to 5% of lesions.³ Currently, there is no standard for treatment of carotid ISR. Most of the knowledge gained about ISR stems from coronary research. The early percutaneous approach to the management of coronary ISR was with repeat POBA. However, the incidence of re-restenosis has ranged from 37–50% angiographically and 14–30% clinically.^4–6 The rationale for using the CB in ISR stems from its ability to achieve acute luminal gain without vessel wall dilation and with minimum tissue injury.^7,8 ISR lesions tend to be more resistant than de novo lesions because of the presence of more smooth muscle cells and proliferative cells and fewer macrophages, collagen and tissue factor. The longitudinal blades of the CB concentrate the dilation force, creating radially directed fissures and enabling more resistant stenoses to be overcome. By first scoring the neointimal plaque, the CB decreases the continuity of the fibrous layer and allows the tissue to be pushed out through the struts.10 The acute luminal gain of the CB is achieved by decreasing the amount of plaque volume without causing an increase in the total vessel size. Using intravascular ultrasound to quantitate and qualify cross-sectional coronary lumens, Muramatsu et al. showed that CB angioplasty resulted in no increase in total vessel size, a constant stent area, a decrease in plaque area and an increase in lumen area.¹¹ Therefore, the increase in luminal cross-sectional area CB angioplasty is through plaque compression rather than vessel expansion. In addition, the more organized approach to lesion disruption results in less vessel injury compared to percutaneous transluminal coronary angioplasty (PTCA). In a study by Inoue et al., PTCA lesions expressed upregulated MAC-1 (CD11b/CD18) and increased circulating ICAM-1 levels compared to angioplasty using a CB.12 This decrease in vessel wall inflammation results in lower rates of restenosis. Adamian et al. showed improved clinical and angiographic outcomes at 6 months with CB compared with rotational atherectomy, repeat stenting and PTCA.⁹ In this study, although immediate lumen size was not as great after CB as with stent or rotational atherectomy, follow-up minimum luminal diameter in the CB group was significantly larger compared to that obtained with other techniques. This reduction in late lumen loss also correlated with a decrease in major adverse cardiac events at 6 months. Finally, the CB may also limit the rate of repeat restenosis by avoiding injury of the adjacent vessel wall. The atherotomes of the CB decrease the amount of balloon slippage during balloon inflation, thus limiting injury to adjacent segments. Current percutaneous treatment options for ISR of coronary lesions include brachytherapy, repeat POBA, directional or rotational atherectomy, and CB angioplasty.¹³ In this case of carotid ISR, we applied the same principles of therapy used in the treatment of coronary ISR. Since there is no reason to suspect any differences in the pathophysiology of ISR of the carotid artery, we hypothesized that CB angioplasty could be safely utilized in the carotid arteries and might be useful for treating resistant lesions. Limitations of this study include the observational nature of case reports. In addition, this procedure was performed within the last 3 months; therefore, we have no long-term follow-up information on the patient except for the absence of any clinical events including death, myocardial infarction, cerebrovascular accident or transischemic attack. Finally, there are no supporting data to confirm that using a CB undersized for the artery followed by appropriately sized balloons does not cause significant vessel wall disruption. Larger CBs specifically designed for the peripheral circulation should be available soon and will obviate the need for additional dilatation with a non-cutting balloon.