Carotid artery stenting (CAS) is being performed more frequently with the recent Centers for Medicare and Medicaid Services approval of transcarotid artery revascularization for asymptomatic patients. Having identified a number of carotid stent fractures in our practice, we studied the incidence of carotid stent fractures and its impact on CAS durability.

Recent publications regarding outpatient sites of service for peripheral vascular interventions (PVIs) have highlighted the need for broader awareness of the economic realities of these sites of service. We congratulate Dr Sober et al1Sorber R. Dun C. Kawaji Q. Abularrage C.J. Black J.H. Makary M.A. et al.Early peripheral vascular interventions for claudication are associated with higher rates of late interventions and progression to chronic limb threatening ischemia.J Vasc Surg. 2023; 77: 836-847.e3Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar on their paper published in this issue regarding the potential implications of early intervention on patients with newly diagnosed intermittent claudication (IC). It was very rewarding to see that nearly 97% of the cases evaluated met the approved societal standards for the management of IC. Of the approximately 3% that underwent PVI earlier than current recommendations, a significant portion of those also underwent late PVI with inferior outcomes to those not receiving early PVI. For this study, the authors have presented an analysis of Medicare claims data for the years 2015 through 2017 with a median follow-up of 4.4 years. A total of 187,442 patients were newly diagnosed with claudication. These patients were separated into two groups by time from diagnosis to intervention for claudication. The authors focused on the group of patients who had a first peripheral vascular intervention (PVI) within 6 months of the diagnosis of IC. The physicians performing these early PVI were subdivided into a high use group (those physicians performing procedures at a rate greater than 2 standard deviations from the entire group) and those who are standard users. The authors speculate that the high use cohort may have been motivated by economic factors in the choice of early intervention but note that they cannot confirm this based on the claims data. The authors postulate that office-based lab (OBL) or ambulatory surgical center (ASC) reimbursement may present a compelling reason to recommend early intervention. They designate these venues (OBL and ASC) as high reimbursement settings. The authors do disclose and recognize the limitations of the Centers for Medicare and Medicaid Services (CMS) database evaluation. This includes the inability for the CMS claims data to quantify the degree of IC symptoms, the lack of objective testing data available, the lack of laterality documented, and the possibility that the early PVI interventions were due to significantly worse symptoms or an early failure of medical therapy. In addition, those with early PVI had a significantly higher smoking and hypertension prevalence – both suggesting the potential for a more significant disease process, leading to more severe symptoms failing medical management and thus earlier PVI. The analysis addresses the very important topic of intermittent claudication and the impact of early peripheral vascular intervention and their conclusions would indicate that that additional randomized control trials are needed with outcomes data and some element of severity evaluation. But, as has been demonstrated in previous publications, we feel compelled to address the characterization of OBLs as “high reimbursement settings”. This terminology appears repeatedly in presentations and publications and it is apparent that a true understanding of the finances of the OBL site of service is needed. It is imperative that the narrative of “high reimbursement settings” be debunked and it is evident that some education is needed to provide the appropriate framework for understanding the OBL as a site of service. Defining this site of service as a “high reimbursement setting” suggests that there is a financial windfall for providing any peripheral vascular intervention in an OBL. This is incorrect and fails to recognize the provision of needed outpatient sites of service for our communities and patients. To clarify the role of the OBL as a site of service, it is important to understand how OBLs are established, how they operate, and how they are reimbursed compared to the hospital outpatient setting. The development of a site capable of providing high-quality, expert vascular intervention requires significant investment. Consider the costs to rent or buy space sufficient for development of a center. This initial capital investment will have the added risk of a multiyear guarantee of payments from the provider – a personal guarantee that will remain whether the site is successful or not. Additional capital investment, again with financial risk and personal guarantees, is needed for the imaging systems, ultrasound equipment, computers, vital monitors, crash cart with equipment, and the list goes on. Consider if you had to purchase all of equipment that you see in the Cath lab in the hospital and you will soon recognize the costs necessary to establish this site of service. On top of this, and included in the reduced Medicare fee for the procedure, are the costs associated with staffing the OBL. A manager, nursing personnel, medical assistants, front desk personnel, radiology technicians, etc. These costs have become significantly higher in the past few years, with hiring and maintaining staff more difficult with the current shortages experienced by all sites of service, including hospital settings. We all need to understand that the payment to the facility covers all of these components as well as the costs associated with the intervention itself. Sterile packs, sheaths, preps, medication, wires, angioplasty balloons, stents, atherectomy devices, insufflators, contrast, heparin, emergent rescue medications, antibiotics – all the supplies needed to perform a highly advanced endovascular procedure just as it is provided in the hospital setting. As is quite evident, the cost to provide this highly efficient, patient-focused, and expert vascular care is significant and has been impacted by supply shortages, inflation, and increased overhead. Should the case be quite complex, the supplies used often lead to a loss compared to the reimbursement received. It is in this reality that the labelling of OBLs as “high reimbursement settings” is not accurate. The fact is, the reimbursement for any office-based procedure performed in the OBL site is 20% to 40% less than the exact same procedure in the hospital outpatient setting. Yet, patient and physician satisfaction, efficiency, and overall value of such an OBL procedure is significantly higher than in the hospital setting. Yes, the same procedure provided in the OBL costs Medicare significantly less than in the outpatient hospital setting. The risks of all the expenses required to provide such procedures falls upon the OBL and its owners. CMS provided for payments for PVI in the OBL in 2008, recognizing that these procedures could be performed in this outpatient site of service with safety, efficacy, and at a substantial savings to the system. They recognized a streamline efficiency of the office setting over the hospital setting. Implications that procedures are being performed in OBLs due to a significant financial windfall does not recognize the costs and risks associated with establishing and operating an OBL. The significant shift of vascular care to outpatient procedures is not going to abate. The ability for the OBL to provide improved access, patient satisfaction, and significant cost reductions to CMS and payors should be highlighted and supported. Without doubt, there will be outliers and those that provide interventions outside of the norm, but, as this article reports, nearly 97% of cases were performed within approved practice guidelines. As we embrace the continued evolution of our vascular specialty, we need to recognize the inevitable shift that is occurring. The majority of all vascular procedures will be outpatient procedures. Many of the current hospital systems are not efficient, are not patient friendly, have poor patient satisfaction, and are terribly inefficient for the busy vascular specialist to provide necessary patient care. Any opportunity to elevate the standard of care for our patients, to promote safe, effective, and value-based care to our communities, needs to be embraced and strengthened. The OBL provides a site of service that can provide efficient, expert, and indicated vascular care that is patient focused. It provides improved patient satisfaction, provider satisfaction, more time to provide essential services to the community, and significant cost savings to the patients, Medicare, and all payors. An analysis of the cost benefits, improved patient centered access, and the undeniable need for outpatient vascular services that can be, and are currently provided, in the OBL is much overdue.

We retrospectively evaluated the application of proposed carotid artery stenosis surveillance guidelines to historic patient populations within our vascular lab database. We specifically examined the rate of complex plaque morphology present in the newly excluded patient population. We have identified a significant patient population with distinct plaque morphologies which are suggestive of future clinical progression that would be excluded from follow-up imaging. We performed a single-center retrospective study examining all carotid artery studies within our IAC certified lab from January 1, 2020, to December 31, 2020, that were identified as having moderate carotid artery stenosis (50%-69%) based off our current protocols using a peak systolic velocity (PSV) of 125 to 230 cm/s and internal carotid artery/common carotid artery ratios ranging from 2 to 4. These studies were then compared to the new recommendations of PSV of >180 cm/s or a ratio of >2.0. We excluded the studies that were moderate stenosis per the new guidelines and examined the studies that would be excluded based on the same guidelines for the presence of calcified or ulcerative plaques. Of the 1076 examinations performed that identified moderate carotid artery stenosis based upon the old criteria, only 782 of these studies demonstrated similar hemodynamically significant stenosis. We examined the remaining 294 studies and found 205 (69.7%) of those studies possessed imaging characteristics concerning for complex plaques (Table, Figure). The increase of PSV to 180 would recategorize 19% of our patients examined over 1 year to <50% stenosis and based upon current recommendations, would be lost to follow-up surveillance for disease progression. Our data suggest currently recommended guidelines would exclude a significant number of patients from routine surveillance that demonstrate plaques that could pose a risk for clinical progression. Our data suggest that more prospective data should be obtained, particularly that pertaining to risk factors that would place the patient at risk for plaque progression, prior to adopting the newly recommended surveillance guidelines.TablePatient dataModerate stenosis per old criteria1076Moderate stenosis per proposed changes782Patients who would be excluded294Patients with concerning plaque morphology205 Open table in a new tab

Carotid artery stenting (CAS) is accepted as an alternative to carotid endarterectomy for high-risk patients with significant carotid occlusive disease. A rare complication of this approach is stent fracture. The incidence and clinical significance of carotid stent fractures are not well studied. To better understand the incidence of stent fracture and to assess whether fracture is associated with in-stent restenosis, we provide this update to our prospectively evaluated CAS patients. Our study population includes patients who underwent CAS between January 2002 and December 2017. Patients were consented and prospectively evaluated for stent fractures by anteroposterior and lateral cervical radiographs. All fractured stents were examined by duplex ultrasound at 1 month, 6 months, and annually thereafter, with a minimum 2-year follow-up. The fracture prevalence was then calculated as a percentage of the total number of stents placed. A subset of these patients had a second radiograph 1 to 6 years after the initial radiograph to assess for late fracture development. A total of 181 patients with 206 stents have been evaluated to date, with 24 fractures identified for a fracture incidence of 11.7% during the course of our study. Of the 206 stents, 95 stents were also evaluated with a second radiograph between 1 and 6 years later, identifying 7 late stent fractures with a late fracture rate of 8.1%. Of the 24 patients with carotid stent fractures, 2 patients developed in-stent restenosis, of whom only one required reintervention. Carotid artery stent fracture occurs at the rate of 11.7%. Furthermore, late stent fractures have also been identified. Currently, there is not an accepted protocol to assess for stent fractures, nor have there been morbidities identified with stent fractures. Given the significant incidence of stent fracture identified in this study, we recommend further prospective study to confirm the incidence of carotid stent fracture and to assess the relative risk of in-stent restenosis of fractured stents.

This is a case report and literature review of a patient with severe tandem carotid lesions in an irradiated field after radical neck dissection with tracheostomy, contralateral carotid occlusion, and contraindication to carotid artery stenting. We conducted a systematic review of the English language literature with information on severe tandem carotid lesions in a hostile field (previous surgical intervention, irradiation) and contralateral carotid occlusion. We present the case of a 71-year-old woman with asymptomatic, severe carotid artery stenosis and a past medical history significant for laryngeal cancer status post laryngectomy with stoma, radical neck dissection, and neck irradiation. Aortic arch and carotid angiography demonstrated a left internal carotid artery (ICA) occlusion, right common carotid artery (CCA) stenosis of 80%, right ICA stenosis of 50% to 60% with severe tortuosity, and occluded right external carotid artery. Given the severe ICA tortuosity with tandem lesions, carotid artery stenting was not feasible, and we proceeded with carotid endarterectomy, ICA resection, and primary anastomosis. Intraoperatively, the ICA was mobilized and the proximal ICA was resected, thus addressing the tortuosity and the distal tandem lesion. For the proximal tandem lesion located in the CCA, we performed a standard endarterectomy of the proximal portion of the CCA lesion and an eversion endarterectomy of the distal transected CCA. Next, we performed an end-to-end anastomosis of the ICA to the CCA. This was completed with a Sundt shunt in place, given the contralateral ICA occlusion. Postoperatively, the patient has done well and continues to be free of any complication, with duplex ultrasound demonstrating patency. After a thorough literature review, it is clear that this in an unusual case with a novel solution. The patient’s prior radical neck dissection with tracheostomy and irradiation would generally have made her an ideal candidate for carotid artery stenting. However, the patient was at high risk for carotid artery stenting, given the tortuosity and tandem lesions. The literature provides ample data on the benefits of carotid artery stenting for carotid stenosis in hostile necks. However, there is very little information clarifying how to approach lesions in a hostile neck when they are not amenable to stenting. Our case represents a novel open carotid endarterectomy approach to tandem lesions with associated tortuosity in a hostile operative field.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Trans-carotid artery revascularization (TCAR) with the ENROUTE Transcarotid Neuroprotection System (Silk Road Medical, Sunnyvale, Calif) combines direct carotid access with blood flow reversal as cerebral protection during carotid stent placement. The Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure (ROADSTER) investigational device exemption trial studied TCAR using Food and Drug Administration (FDA)-approved carotid stent systems designed for transfemoral delivery. A subset of patient data was used to support FDA approval of a shorter 57-cm-length delivery system (ENROUTE Transcarotid Precise Stent System). The ROADSTER investigational device exemption trial was a prospective, single-arm, multicenter clinical trial to evaluate the safety and effectiveness of TCAR in high-risk symptomatic patients with ≥50% stenosis and asymptomatic patients with ≥70% stenosis. The primary end point was a composite of stroke, myocardial infarction (MI), and death at 30 days. Secondary end points included cranial nerve injury and acute device, technical, and procedural success. An independent clinical events committee adjudicated all major adverse events. Of the 67 lead-in and 141 pivotal patients enrolled, 52 patients were treated with the Precise PRO Rx Carotid Stent System (Cordis, Bridgewater, NJ). Data from these 52 patients were used to support FDA approval of the shorter length ENROUTE Transcarotid Stent System. From November 2012 to July 2014, 52 patients treated with the Precise stent were enrolled at 8 of 18 sites that participated in ROADSTER. Mean age was 73.0 years, 42.3% were female, and 23.1% were symptomatic; 51.9% of patients were ≥75 years old, and 23.1% were ≥80 years old. There were no major strokes, MIs, deaths, or cranial nerve injuries. One patient (1/52 [1.9%]) had a minor stroke. Acute device success, technical success, and procedural success were 100%, 100%, and 98.1% respectively. Of the 15 patients treated at our institution, the technical success was 100%, and the stroke/death/MI was 0%. The Precise stent data from the ROADSTER trial indicate the lowest major adverse events of any carotid stent trials, 0% major stroke/death/MI and a 1.9% minor stroke/death/MI, leading to the FDA approval of the first transcarotid stent. Furthermore, the ROADSTER study highlights that Precise stent stroke/death/MI with transcarotid ENROUTE neuroprotection (1.9%) is lower than what was observed with Precise stent transfemoral neuroprotection (4.8%) as seen with the Stenting and Angioplasty with Protection in Patients with High Risk for Endarterectomy (SAPPHIRE) trial.

Carotid artery stenting (CAS) is accepted as an alternative to carotid endarterectomy (CEA) for high-risk patients with significant carotid occlusive disease. However, the data for carotid stent fracture incidence is inconclusive. Furthermore, the true clinical consequences of such fractures is not well studied. To better evaluate the incidence of CAS fracture and to assess whether fracture is associated with recurrent stenosis, we prospectively evaluated CAS patients for fracture and restenosis. Patients who underwent CAS between January 2002 and January 2014 were prospectively evaluated for stent fractures by AP and lateral cervical X-ray images. All stents were examined by duplex ultrasound at 1 month, 6 months, and annually post-CAS with a minimum 2-year follow-up. The fracture prevalence was then calculated as a percentage of the study population. Carotid duplex results were correlated to those with and without stent fractures. A subset of these patients had a second X-ray from 1 to 6 years after their initial X-ray to assess for late fracture development. A total of 168 stents have been evaluated to date, with 11 fractures identified for a fracture incidence of 6%. Of the 168, 60 stents were also evaluated with second X-ray between 1 and 6 years later, identifying 5 late stent fractures and a late fracture rate of 8%. Stent fractures were not associated with increased risk of restenosis at 2 years' follow-up, nor there was any associated neurologic events attributable to stent fractures. CAS fracture occurs at the rate of 6%, and subsequent late stent fractures have also been identified. Currently there is not an accepted protocol to assess for stent fractures nor have there been morbidities identified with CAS fractures. At time of writing this abstract, those new fractures are being evaluated by an experienced vascular technologist to determine any specific findings on duplex that could diagnose stent fractures. Given the significant incidence of CAS fracture identified in this study, we recommend further prospective study to confirm the incidence, to assess for possible late stent fracture and to assess for late morbidity associated with CAS fracture.