Is carotid artery stenting equivalent or superior to carotid endarterectomy for treatment of carotid artery stenosis?

A best evidence topic in vascular surgery was written according to a structured protocol. The question addressed was whether carotid artery stenting (CAS) is equivalent or even superior to carotid endarterectomy (CEA) for the treatment of significant carotid artery stenosis. Four hundred and ninety-four papers were identified, of which 14 papers including five randomised controlled trials (RCTs) presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. We conclude that the risk of peri-procedure stroke or death was similar for patients treated with carotid artery angioplasty+/-stenting and those treated with surgery. However, CAS did reduce the risk of minor complications at the site of vascular access, the incidence of cranial nerve injury, and may reduce economic costs due to shorter hospital stays and earlier return to work. Long term follow-up of these patients is, however, lacking. There are currently four large multi-centre RCTs in progress and their results will determine whether CAS will surpass CEA as the gold standard in the future.     

Is the incidence of recurrent carotid artery stenosis influenced by the choice of the surgical technique? Carotid endarterectomy versus saphenous vein bypass

Purpose: The purpose of this study is to compare the incidence of recurrent carotid artery stenosis (RCS) after carotid endarterectomy (CEA) and saphenous vein grafting (SVG) in patients with bilateral carotid artery stenosis.Methods: Between 1978 and 1990, 1483 patients underwent carotid artery surgery at our institution. Fifty-one patients were diagnosed with bilateral carotid artery stenosis and were included in a prospective study that consisted of performance of CEA on one side and SVG on the other. The patients consisted of 34 men and 17 women. Forty patients had symptoms, and 11 were symptom free with severe (≥90%) bilateral carotid artery stenosis. All patients underwent a two-stage procedure with an operative interval that ranged from 5 days to 6 months.Results: All patients survived, and no permanent postoperative neurologic deficit was observed. Follow-up was available for all patients and ranged from 6 to 150 months (mean 52 months). Serial Doppler studies were performed in all patients at 6- to 9-month intervals. Unilateral RCS (≥80%) occurred in two cases (two of 102); one in a CEA (one of 51) and one in the distal anastomosis of a SVG (one of 51) at 6 and 8 months, respectively, after operation. The reoperative surgical technique performed in both cases was a SVG.Conclusions: The incidence of RCS requiring repeat operation after carotid artery surgery is not influenced by the choice of the surgical technique, namely CEA or saphenous vein bypass. (J VASC SURG 1994;20:821-5.)     

Duplex criteria for determining ≥50% and ≥80% internal carotid artery stenosis following carotid endarterectomy with patch angioplasty

The purpose of this study was to determine optimal velocities for detecting ≥50% and ≥80% restenosis prior to considering carotid intervention/carotid artery stenting (CAS) after carotid endarterectomy (CEA) with patching in symptomatic and asymptomatic patients. Two hundred CEA patients with 195 pairs of imaging (duplex ultrasound versus computed tomography angiography [CTA]/carotid arteriography) were analyzed. Peak systolic velocities (PSVs), end diastolic velocity (EDV) and internal carotid artery/common carotid artery (ICA/CCA) ratios were correlated to angiography. Receiver operator characteristic (ROC) curves determined optimal velocity criteria in detecting ≥50% and ≥80% restenosis. The mean PSVs for ≥50% and ≥80% restenosis were 248 and 404 c/s, respectively (P < 0.001). A PSV of ≥213 c/s was optimal for ≥50% restenosis with sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy (OA) of 99%, 100%, 100%, 98% and 99%, respectively. An ICA PSV of 274 c/s was optimal for ≥80% restenosis with sensitivity, specificity, PPV, NPV and OA of 100%, 91%, 99%, 100% and 99%, respectively. ROC analysis showed that PSVs were significantly better than EDVs and ICA/CCA ratios in detecting ≥50% restenosis. Standard duplex velocity criteria should be revised after CEA using patching. Specific carotid duplex velocities can be used to detect ≥50% and ≥80% restenosis after CEA with patch closure prior to carotid intervention/CAS.     

Is carotid artery stenting a fair alternative to carotid endarterectomy for symptomatic carotid artery stenosis? A commentary on the AHA/ASA guidelines

The recent guidelines by the American Heart Association/American Stroke Association (AHA/ASA) and several other associations recommended carotid artery stenting (CAS) as an alternative to carotid endarterectomy (CEA) for symptomatic patients (Class I; Level of Evidence: B). The term "alternative" may easily be misinterpreted as "equivalent" to justify the widespread use of CAS. However, current evidence indicates that for symptomatic patients, CAS produces inferior outcomes compared with CEA. It is likely that with technical improvements, better patient selection, and better physician experience, CAS outcomes will improve in the future. CAS may then become a fair alternative to CEA, at least in certain patient subgroups. Based on current evidence, however, we are not there yet and it seems unfair to spin the AHA/ASA guidelines to conclude that we are.     

Is carotid angioplasty and stenting more cost effective than carotid endarterectomy?

OBJECTIVE: Carotid angioplasty and stenting (CAS) has been advocated as a minimally invasive and inexpensive alternative to carotid endarterectomy (CEA). However, a precise comparative analysis of the immediate and long-term costs associated with these two procedures has not been performed. To accomplish this, a Markov decision analysis model was created to evaluate the relative cost effectiveness of these two interventions. METHODS: Procedural morbidity/mortality rate for CEA and costs (not charges) were derived from a retrospective review of consecutive patients treated at New York Presbyterian Hospital/Cornell (n = 447). Data for CAS were obtained from the literature. We incorporated into this model both the immediate procedural costs and the long-term cost of morbidities, such as stroke (major stroke in the first year = $52,019; in subsequent years = $27,336/y; minor stroke = $9419). We determined long-term survival rate in quality-adjusted life years and lifetime costs for a hypothetic cohort of 70-year-old patients undergoing either CEA or CAS. Our measure of outcome was the cost-effectiveness ratio. RESULTS: The immediate procedural costs of CEA and CAS were $7871 and $10,133 respectively. We assumed major plus minor stroke rates for CEA and CAS of 0.9% and 5%, respectively. We assumed a 30-day mortality rate of 0% for CEA and 1.2% for CAS. In our base case analysis, CEA was cost saving (lifetime savings = $7017/patient; increase in quality-adjusted life years saved = 0.16). Sensitivity analysis revealed major stroke and death rates as the major contributors to this differential in cost effectiveness. Procedural costs were less important, and minor stroke rates were least important. CAS became cost effective only if its major stroke and mortality rates were made equivalent to those of CEA. CONCLUSION: CEA is cost saving compared with CAS. This is related to the higher rate of stroke with CAS and the high cost of stents and protection devices. To be economically competitive, the mortality and major stroke rates of CAS must be at least equivalent if not less than those of CEA.     

External carotid artery shunting during carotid endarterectomy: an alternative for cerebral protection?

OBJECTIVES: to assess the application of external carotid artery (ECA) shunting in cerebral protection during carotid endarterectomy (CEA). DESIGN: prospective study. MATERIALS AND METHODS: the study comprised 137 consecutive patients who underwent CEA under locoregional anaesthesia. Transcranial Doppler was used to monitor the mean velocity of the middle cerebral artery (mv-MCA): (1) before carotid clamping; (2) after clamping both the common and external carotid arteries; (3) after clamping the internal carotid artery alone ("ECA test"). The decision to shunt was based on the occurrence of neurological deficit during carotid clamping. If the ECA test revealed mv-MCA approaching the pre-clamping values ECA shunting was used, whereas the remaining patients in need of a shunt had a standard internal carotid artery (ICA) shunt. RESULTS: shunting was necessary in 12/137 cases (9%). The ECA test indicated that in four cases - 3% of the whole series or 33% of the shunted cases. In these four patients ECA shunting reversed the neurological deficit, and CEA was successfully performed without any complications. CONCLUSIONS: ECA shunting could be considered as an alternative to standard ICA shunting. Suitable cases can be identified on the basis of the ECA test.     

Elongation of the internal carotid artery and abdominal aortic aneurysm: is there a relationship?

BACKGROUND: This study was undertaken to analyze whether there is a relationship between the elongation of the internal carotid artery (e-ICA) and abdominal aortic aneurysm (AAA). METHODS: Forty-three patients had concomitant evidence of an asymptomatic AAA and e-ICA: all of these patients underwent surgical AAA repair, while 25 (58.1%) also underwent surgical e-ICA correction. The 43 patients were compared with a control group of 141 e-ICA subjects with no AAA as regards to age, gender, risk factors and associated diseases. An operative specimen of the aneurysmal wall was obtained in 32 instances (74.2%); an operative specimen of the carotid wall was obtained in 100% of operations. RESULTS: The overall perioperative mortality rate was 0%. Patency of the revascularized ICA was assured in 100% of cases. The perioperative stroke risk rate was 0%. The perioperative morbidity rate for abdominal surgery was 6.9% (3/43). There were three late deaths: one patient died from a major stroke due to occlusion of the unoperated e-ICA. Degenerative dysplastic changes were observed in the tunica media in all carotid specimens; non-obstructive atherosclerotic intimal lesions were superimposed in a few cases. Histological features of "classic" AAA, i.e. thinning of the tunica media underlying the atherosclerotic plaque, were discovered in all but five aortic wall specimens. CONCLUSIONS: The association between e-ICA and AAA is stronger than one would expect from atherosclerosis alone and should not be ignored. A primary arterial disorder of the tunica media seems to lie at the basis of both conditions, so patients with e-ICA should be investigated and followed up for any occurrence of AAA and, vice versa, patients with AAA should be investigated for any presence of e-ICA. On the basis of the results obtained, surgical repair of both conditions is recommended in selected patients.     

In patients undergoing cardiac surgery does asymptomatic significant carotid artery stenosis warrant carotid endarterectomy?

A best evidence topic in cardiovascular surgery was written according to a structured protocol. The question addressed was whether asymptomatic significant carotid artery stenosis (ASCAS) warrants carotid endarterectomy (CEA) in patients undergoing cardiac surgery. 128 Papers were found using the reported search, of these 10 presented represent the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of these papers are tabulated. We conclude that low risk, younger patients with a significant asymptomatic carotid artery stenosis should be considered for carotid endarterectomy at some stage. There is, however, no strong evidence that this must be performed prior to, or during CABG.     

Hemodynamics of in-tandem stenosis of the internal carotid artery: when is carotid endarterectomy indicated?

BACKGROUND: Recent publications have pointed out the importance of evaluating patients with in-tandem stenosis and in particular the association of moderate stenosis of the extracranial internal carotid artery (ICA) with moderate or severe stenosis of the intracranial internal carotid artery. Such evaluations are needed in symptomatic patients before planning carotid endarterectomies because observations have shown that in some cases the removal of an extracranial lesion does not necessarily improve these symptoms. This paper examines the hemodynamic effects of in-tandem stenosis in the internal carotid artery. METHODS: Equations describing flow in arteries are modified to accommodate two regions of stenosis in tandem. An equivalent value of stenosis is derived such that two stenoses in tandem behave as a single stenosis with similar hemodynamic properties. The solution to this problem is solved mathematically and this was used to analyze the observations made in five studies published on in-tandem stenosis of the internal carotid artery. RESULTS: Equivalent stenoses for various values of extracranial and intracranial stenoses are presented. It was found that two stenotic lesions in tandem are not equivalent to a simple summation of both values. A graphical solution is presented to show the hemodynamic effects of both stenoses. CONCLUSIONS: The most critical determinant of hemodynamic compromise when two lesions are in tandem is the larger one. Hence removal of a more proximal lesion may have little effect on a larger distal lesion if the symptoms are due to hypoperfusion. It is important that one distinguish between hypoperfusion and thromboembolic causes of the symptoms. No conclusions about the risk of thromboembolic events after a carotid endarterectomy in the setting of a distal stenosis can be made from this study.     

Octogenarians with contralateral carotid artery occlusion: a cohort at higher risk for carotid endarterectomy?

PURPOSE: Carotid angioplasty and stenting has been proposed as a treatment option for carotid occlusive disease in patients at high risk, including those 80 years of age or older or with contralateral carotid occlusion. We analyzed 30-day mortality and stroke risk rates of carotid endarterectomy (CEA) in patients aged 80 years or older with concurrent carotid occlusive disease. METHODS: From a retrospective review of 1000 patients undergoing 1150 CEA procedures to treat symptomatic and asymptomatic carotid lesions over 13 years, we identified 54 patients (5.4%) aged 80 years or older with concurrent contralateral carotid occlusion. These patients were compared with 38 patients (3.8%) aged 80 years or older with normal or diseased patent contralateral carotid artery and 81 patients (8.1%) younger than 80 years with contralateral carotid occlusion. All CEA procedures involved either standard CEA with patching or eversion CEA, and were performed by the same surgeon, with the patients under deep general anesthesia and cerebral protection involving continuous perioperative electroencephalographic monitoring for selective shunting. Shunting criteria were based exclusively on electroencephalographic abnormalities consistent with cerebral ischemia. RESULTS: The 30-day mortality and stroke rate in patients aged 80 years or older with concurrent contralateral carotid occlusion was zero. CONCLUSIONS: The concept of high-risk CEA needs to be revisited. Patients with two of the criteria considered high risk in the medical literature, that is, age 80 years or older and contralateral carotid occlusion, can undergo CEA with no greater risks or complications. Until prospective randomized trials designed to evaluate the role of carotid angioplasty and stenting have been completed, CEA should remain the standard treatment in such patients.     

Prospective controlled study of carotid endarterectomy with hemashield patch: is it thrombogenic?

The use of patch angioplasty after carotid endarterectomy (CEA) has been shown to have superior results to CEA with primary closure. Polytetrafluoroethylene (PTFE) patches have been shown to have comparable results to autogenous vein patching; however, PTFE has the disadvantage of prolonged hemostasis time. Therefore, many surgeons are using collagen-impregnated Dacron patches (Hemashield[HP]). We believe this is the first prospective controlled study of the use of HP in carotid endarterectomy. This study included 144 consecutive patients who had 151 CEAs with HP. Postoperative duplex ultrasounds were done at 1 month and every 6 months thereafter. The mean follow-up was 12 months (range: 1-30 months). Indications for CEA included symptomatic (64%) and asymptomatic (36%) stenoses. The overall incidence of ipsilateral stroke was 5% (4% perioperative), with a combined TIA and stroke rate of 12%. Incidence of > or =50% recurrent stenosis was 21% (7% symptomatic TIA/stroke) and > or =80% recurrent stenosis was 9%. Kaplan-Meier analysis showed that at 1 year and 2.5 years freedom from > or =50% recurrent stenosis was 78% and 57%, respectively, freedom from > or =80% recurrent stenosis was 92% and 77%, respectively, and a stroke-free survival rate of 94% and 72%, respectively. Women had a 22% and men a 14% recurrent stenosis rate (p=0.04). There was no correlation between other specific risk factors and recurrent stenosis except for hypertension (33% vs 12%, p=0.003). The authors concluded that CEA with HP had a higher incidence of recurrent stenosis (21%), and a higher perioperative stroke rate (4%) after a mean follow-up of 12 months than previously reported using PTFE or saphenous vein patching (2% and 9% recurrent stenosis rates, respectively, and 1% and 0% perioperative stroke rates, respectively after a mean follow-up of 30 months). This raises the question as to whether this patch is thrombogenic in this location. Therefore, a randomized controlled trial comparing this patch with other patches (PTFE or vein) is warranted.     

Does the radial artery provide better long-term patency than the saphenous vein?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the radial artery provides better long-term patency than the saphenous vein. Altogether 379 papers were found using the reported search, of which 12 presented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We concluded that there is evidence that radial artery grafts have a higher rate of patency than saphenous vein grafts. Surgeons can confidently use the radial artery as a second arterial bypass graft, particularly in patients with severe native-vessel stenosis.     

Is a palpable short saphenous vein a useful clinical sign in varicose vein assessment?

The short saphenous vein (SSV) may be palpable in the popliteal fossa in patients with varicose veins. A prospective study has been carried out to determine the significance of this sign in the presence of primary varicose veins. The SSV was assessed by palpation of the popliteal fossa with the knee slightly flexed. Hand-held Doppler insonation (HHD) was also used in the out-patient clinic. All patients had SSV assessment by duplex scanning. One hundred and sixty legs were examined. In 68 the SSV was palpable; 39 (57%) of these had SSV reflux on duplex examination. When the SSV was not palpable (92 legs), only 1% (1 leg) refluxed on duplex scanning. SSV palpability had a 98% sensitivity, 75% specificity, 57% positive predictive value (PPV), and 99% negative predictive value (NPV). In comparison, HHD had 80% sensitivity, 87% specificity, 67% PPV and 93% NPV. The combined tests had 78% sensitivity, 73% specificity, 76% PPV and 100% NPV. Palpation of the SSV is a valuable part of clinical examination. If the SSV is not palpable, it is unlikely to reflux.     

Is saphenofemoral junction reconstruction necessary during stripping of the saphenous vein?

BACKGROUND: Patients who had undergone complete ankle-to-groin stripping of the greater saphenous vein were evaluated retrospectively to assess the necessity of saphenofemoral junction reconstruction during the stripping procedure. Since 1996, in addition to the conventional complete stripping operation, we routinely perform a saphenofemoral junction reconstruction in patients presenting with greater saphenous vein reflux associated with low-grade (grades I-II) saphenofemoral junctional reflux. In this method, the size of the common femoral vein was adjusted to the desired diameter by a running linear suture technique after division of the greater saphenous vein. METHODS: Retrospective evaluation revealed that 73 limbs in 56 patients treated with this technique (group I). This group of patients was matched to another group of 65 patients (78 limbs) with similar characteristics and symptoms (group II) in whom the conventional complete ankle-to-groin stripping of greater saphenous vein was the treatment. The 2 groups were compared with respect to the incidence of complications, including recurrence of varicosities, ecchymosis, lymphocele, lymphorrhagia, wound infection, and paresthesia in the operated extremity. All patients also were evaluated by Doppler ultrasonography at 6 months, 12 months, and annually thereafter to determine the saphenofemoral junction reflux time (valve reflux time). The mean duration +/- SD of follow-up was 6.7 +/- 1.6 years (range, 2.1-10.8 years). RESULTS: Recurrence of varicosity was noted in 14 patients, 3 in group I and 11 in group II (P = .02). There were no statistically significant differences between the 2 groups in terms of ecchymosis, hematoma, lymphocele, lymphorrhagia, wound infection, and paresthesia. At 6 months, a rapid decrease in valve reflux time was noted in group I (P = .0001). In addition, there was a significant improvement in valve reflux time at each subsequent Doppler examination in group I. Group II showed a decrease in valve reflux time, compared with the preoperative value (P = .068). During subsequent Doppler examinations, a decrease in valve reflux time also was noted in group II; this difference reached statistical significance only at 24 months (P = .04). CONCLUSIONS: We believe that saphenofemoral junction reconstruction is a simple technique to perform and that addition of this method to the conventional stripping provides more durable results with a lesser incidence of recurrence. This method should be considered as a treatment modality in patients with greater saphenous vein reflux associated with low-grade (grades I-II) saphenofemoral junctional reflux.