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The effect of carotid stenting on endarterectomy practice e A single institution experience A. Ali, A. O’Callaghan*, T. Moloney, C. Kelly, D. Monoley, A. Leahy Department of Vascular Surgery, Beaumont University Hospital, Dublin, Ireland

article info

abstract

Article history:

Objectives: The number of operations performed per surgeon is thought to determine the

Received 18 December 2013

quality of carotid endarterectomy (CEA) surgery. The advent of carotid artery stenting (CAS)

Received in revised form

threatens to reduce the volume of CEA. This paper assesses CEA and the effects of the

19 March 2014

introduction of CAS service on outcomes.

Accepted 2 April 2014

Design: Retrospective cohort study.

Available online xxx

Methods: Clinical data and results of CEA were reviewed retrospectively for the treatment of carotid stenosis, between January 1988 and December 2010. CEA patients were grouped

Keywords:

into those treated before and after the introduction of CAS to our hospital in 2001.

MESH terms

Results: 757 patients underwent a CEA between 1988 and 2010. The perioperative stroke rate

Endarterectomy

prior to the introduction of CAS was 4.9%, and 3.3% after stent introduction in 2001. In this

Carotid

latter period, 85.5% had symptomatic stenosis which suggests that the patients were not low

Endovascular procedures

risk. The major adverse event rate (inclusive of death and myocardial infarction) post intro-

Outcome assessment (healthcare)

duction of CAS from 2001 to 2010 was 4.1%. There was no correlation between post-operative stroke/MAE and procedure volume, despite the trend of decreasing CEA numbers over time. Conclusion: The introduction of carotid artery stenting has led to a decrease in carotid endarterectomy volume. However, outcomes in our high risk patient population are acceptable. Therefore, CEA remains the procedure of choice for carotid artery revascularization. ª 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Introduction Carotid Endarterectomy (CEA) is an effective therapy for the secondary prevention of stroke, in patients with intermediate to high grade stenosis.1 It remains the gold standard interventional modality, despite efforts to find a minimally invasive alternative.2 The introduction of stenting has however led to a decreased procedural volume.3 Given the contemporary reliance on procedural volume as an indicator of quality, we sought to assess the effect of carotid stenting

on endarterectomy institution.8

volumes,

and

outcomes,

in

our

Methods Patients All patients undergoing CEA in Beaumont University Hospital between January 1988 and December 2010 were included in this analysis. Beaumont is an eight hundred bed acute

* Corresponding author. Tel.: þ353 863874590. E-mail address: [email protected] (A. O’Callaghan). http://dx.doi.org/10.1016/j.surge.2014.04.001 1479-666X/ª 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Please cite this article in press as: Ali A, et al., The effect of carotid stenting on endarterectomy practice e A single institution experience, The Surgeon (2014), http://dx.doi.org/10.1016/j.surge.2014.04.001

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t h e s u r g e o n x x x ( 2 0 1 4 ) 1 e4

hospital, affiliated to the Royal College of Surgeons in Ireland, and has, along with an Academic Department of Vascular Surgery, the National Referral Centre for Neurosurgery. There is consequently an expertise in interventional neuroradiology, resulting in the provision of a carotid stenting service since 2001. A weekly multi-disciplinary meeting is held between the Departments of Stroke Medicine, Vascular Surgery and Neuro-radiology, where potential operative candidates are discussed. There is no institutional consensus as to which patients should be preferentially offered surgery or stenting (hostile neck anatomy cases excepted). The decision therefore is determined by the bias of the neurological service, and we have noticed that an ever increasing number of patients are being referred for stenting because of the perceived benefits of minimally invasive intervention. Carotid Endarterectomies are undertaken by three consultant vascular surgeons, one of whom either performs the procedure, or supervises the performance of a senior vascular trainee. Cases were identified using a combination of a hospital database, and hand searches of the operative room logbooks for the period. Complete clinical records needed to be available to satisfy the inclusion requirements. Given that our objective was to examine the effects of carotid stenting on endarterectomy outcomes, we grouped CEA patients into those occurring pre and post the introduction of stenting (2001). Baseline demographic data and risk factors were obtained for each patient, as well as the indications for intervention and are shown in Table 1. Technical factors, such as shunt and patch use, and outcomes were recorded.

Post-operative stroke was defined as any new symptoms or exacerbation of existing symptoms attributable to cerebro-vascular ischemia. Assessment of any suspected post-operative event included bed-side carotid duplex, immediate and delayed brain imaging, and multi-disciplinary stroke team input. Strokes were divided on the basis of severity into mild, moderate, and severe on the basis of NIHSS criteria.4 Major Adverse Events (MAE) refers to the combination of post-operative strokes, myocardial infarction, and 30 day mortality rates.

Operative technique A conventional endarterectomy was performed in each case; access to the plaque facilitated by a longitudinal incision over the bifurcation and extending into the internal carotid artery.5 Procedures were performed under general anesthesia, and five thousand International Units of Unfractionated Heparin was administered prior to arterial clamping. The use of arterial shunts, patches and distal tacking sutures was at the discretion of the operating surgeon.

Analysis Data were stored in tabulated format on Microsoft excel, and data analysis conducted with SPSS. Statistical analysis was conducted using Fischer exact test and Spearman rank order correlation, as appropriate.

Ethical approval Outcomes The outcome measures were the incidence of post-operative stroke, myocardial infarction and thirty day mortality.

Give the nature of the study, and the absence of impact on ongoing patient care, an ethical approval submission was not deemed to be warranted by the hospital review board.

Table 1 e Demographics and risk factors. CEA patients divided into those occurring pre and post carotid stenting was introduced (pre-1988e2000 and post-2001e2010).

Sex distribution Mean Age (years) Indication Co-morbidities

Mean ASAa Outcome

a

Male Female Asymptomatic Symptomatic Coronary artery disease Renal insufficiency Hypertension Hyperlipidemia COPD Smoking Diabetes Peripheral Vascular Disease Nerve injury Post-operative bleeding/ haematoma Infection Stroke Death within 30 days

CEA pre introduction of stenting N ¼ 488

CEA post introduction of stenting N ¼ 269

330 (67.6) 158 (32.4) 65 40 (8.2) 448 (91.8) 161 (33) 11 (2.3) 262 (53.7) 106 (21.7) 39 (8) 422 (86.5) 50 (10.2) 123 (25.2) III 7 (1.4) 30 (6.1)

192 (71.4) 77 (28.6) 67 39 (14.5) 230 (85.5) 120 (44.6) 9 (3.3) 207 (77) 211 (78.4) 15 (5.6) 147 (54.6) 59 (21.9) 60 (22.3) III 4 (1.5) 9 (3.3)

7 (1.4) 24 (4.9) 5 (1)

2 (0.7) 9 (3.3) 1 (0.4)

P value NS

P < 0.05 P< NS P< P< NS P< P< NS

0.001 0.001 0.001 0.001 0.001

NS NS NS NS NS

American Society of Anesthesia score.

Please cite this article in press as: Ali A, et al., The effect of carotid stenting on endarterectomy practice e A single institution experience, The Surgeon (2014), http://dx.doi.org/10.1016/j.surge.2014.04.001

t h e s u r g e o n x x x ( 2 0 1 4 ) 1 e4

Results 757 patients underwent a CEA between 1988 and 2010. Complete records were available for each, facilitating the inclusion of all cases. A breakdown of demographics and risk factors is shown in Table 1. CEA cases were divided into two groups; pre and post the introduction of carotid stenting. Overall, the CEA patients were high risk, with the overall coemorbidity profile of the CEA patients remaining unchanged post the introduction of stenting. Figure 1 represents the annual CEA volumes before and after the introduction of stenting.

Post-operative CVA and MAE Stroke rate pre 2001 was 4.7%, improving to 3.3% in the latter decade, to 2010. This is illustrated in Table 1. A more complete breakdown of the stroke and major adverse events since 2001 is shown in Table 2, along with the NIHSS score. In that period, there were nine post-operative strokes, one myocardial infarct, and one death within thirty days, giving a MAE rate of 4.1%. Only one of the strokes was classified as major, the remaining seven equally distributed between mild and moderate. There was no relationship between post-operative stroke/MAE and procedure volume, despite the trend of decreasing CEA numbers over time.

Discussion Our experience has shown that the introduction of CAS, as an alternative therapeutic modality, has led to a reciprocal decrease in the number of endarterectomies performed. Nonetheless our outcomes, for what is now a low volume procedure, remain on a par with best practice for symptomatic disease.6 The association between provider volume and outcome was first made in the 1950’s, with the demonstration

Fig. 1 e Trends in carotid intervention. CEA Carotid endarterectomy (blue). CAS Carotid Stenting (orange).

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of inferior care in non-teaching hospitals, and has been replicated across every medical speciality since.7 The consensus appears to be that high volume surgeons and hospitals, with some exceptions, have superior results. Furthermore, healthcare purchasers, exemplified by the leapfrog group, have attempted to use procedure volume as a surrogate quality standard, through the insistence of minimum hospital volumes to remain eligible for funding.8,9 This has consequent effects on the continued viability of the procedure at those low volume hospitals. While this positive relationship may be intuitive, many of the studies are based on composite analyses of heterogeneous databases, with consequent effects on the validity of the data generated. This has been shown in a carotid specific context when using the United States National Inpatient Sample database to base conclusions.10 Comparisons, using procedural numbers alone, are further compounded by hospital variations in utilization and care processes for carotid surgery. Use of a prospective database, with risk adjustment, has failed to uphold the volume outcome relationship for carotid endarterectomies, and instead found that the process of care was a more accurate determinant of outcome.11 Additionally, many of the earlier studies include carotid procedures performed by general surgeons, a remnant of vascular surgery’s origins, so perhaps explaining in part the sub-optimal results.12 The evolution of vascular surgery to a mono-speciality has in itself led to better results, owing to improved training. Further examination of the volumeeoutcome relationship suggests that composite procedural volumes (across the entire speciality) are perhaps more important than procedure specific volumes and should be considered when determining outcome measures.13 While the effect of both surgeon and hospital volume on safety is accepted, it is clear from this and other such studies, that the effect is complex and likely non-linear. There is evidence that minimum threshold volumes are important, with any further increases not providing a benefit in of themselves.14 The adage ‘practice makes perfect’ is apt both in terms of hospital process and surgeon ability, but likely of greater importance are factors such as the proportion of symptomatic patients operated on, and the adherence to evidence based practice. The subspecialisation of our clinical team, along with a composite experience in both lower extremity and aortic disease, likely mitigates against the decrease in volume of carotid endarterectomies. Our designation as a university teaching hospital also helps to ensure that the care provided is in line with contemporary best practise. We are certainly not alone in this regard, many low volume centers have published institutional results that match or surpass ‘best practise’.15,16 The only selection criteria applied in this study were the preferences of the referring physicians. The neurology services, during the period from 2001 to the present, have elected to treat their patients endovascularly, using carotid stenting. No patient referred to the surgical service, with appropriate pathology and excluding hostile neck anatomy, has been turned down for surgery. This is reflected in our results; the majority of the patients falling into a high risk category. There is therefore a selection bias in this study, based on the referral source. While this may be considered a weakness, it is in fact

Please cite this article in press as: Ali A, et al., The effect of carotid stenting on endarterectomy practice e A single institution experience, The Surgeon (2014), http://dx.doi.org/10.1016/j.surge.2014.04.001

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Table 2 e Post-operative stroke and MAE post introduction of CAS. Year Procedure number Post-op CVA Mild Moderate Severe Post-op MAE a b

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

44 0 2 1 4b

30 1 0 0 1

23 0 0 0 0

29 0 0 0 0

27 0 0 0 0

26 0 0 0 0

37 2 1 0 3

26 0 1 0 2a

14 0 0 0 0

13 0 1 0 1

includes one additional patient who suffered a post-operative MI. includes one death, in the patient who suffered a severe post-operative CVA.

indicative of practice in the modern era, where continuing referral for endovascular treatment, dictated by referring physician bias, will inevitably decrease the volume of patients being referred for carotid endarterectomy. Our neuroradiology colleagues in Beaumont hospital recently reported their stenting results, up to June 2011.17 With a similar high risk patient profile, but a lower proportion of symptomatic patients (62% versus 84% in the endarterectomy group) their reported stroke rate was similar, at 3.2%, while their MAE rate was higher, at 7.5%. The present reliance on volume as a surrogate of quality, and thereby safety, has widespread implications for training, credentialing, and continuing viability of CEA. The decreasing volumes shown in our study mirror the paradigm shift to minimally invasive alternatives, often in the absence of demonstrated superiority. Despite the decreasing volume, our outcomes have matched quality standards, and remain superior to stenting. However the decreasing exposure to CEA for trainees will have negative connotations and threaten the continued viability of the procedure.

references

1. Rothwell PM, Eliasziw M, Gutnikov SA, Fox AJ, Taylor DW, Mayberg MR, et al. Analysis of pooled data from the randomised controlled trials of endarterectomy for symptomatic carotid stenosis. Lancet 2003;361(9352):107e16. 2. Liu Zhen-Jie, Fu Wei-Guo, Guo Zhen-Ying, Shen Lai-Gen, Shi Zhen-Yu, Li Jia-Hui. Updated systematic review and metaanalysis of randomized clinical trials comparing carotid artery stenting and carotid endarterectomy in the treatment of carotid stenosis. Ann Vasc Surg 2012;26(4):576e90. 3. Skerritt Matthew R, Block Robert C, Pearson Thomas A, Young Kate C. Carotid endarterectomy and carotid artery stenting utilization trends over time. BMC Neurol 2012;12(1). 4. Brott T, Adams Jr HP, Olinger CP, Marler JR, Barsan WG, Biller J. Measurements of acute cerebral infarction: a clinical examination scale. Stroke 1989;20:864e70. 5. Cao PG, De Rango P, Zannetti S, Giordano G, Ricci S, Celani MG. Eversion versus conventional carotid endarterectomy for preventing stroke. Group Cochrane Database Syst Rev 2006;(1).

6. Brott TG, Halperin JL, Abbara S, Bacharach JM, Barr JD, Bush RL, et al. 2011. ASA/ACCF/AHA/AANN/AANS/ACR/ ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline on the management of patients with extracranial carotid and vertebral artery disease: executive summary: a report of the American College of Cardiology Foundation/American Heart Association task force on practice guidelines, and the American Stroke Association, American Association of Neuroscience Nurses. Circulation 2011;124(4):e54e130. 7. Lee JA, Morrison SL, Morris JN. Fatality from three common surgical conditions in teaching and non-teaching hospitals. Lancet 1957;270(6999):785e90. 8. Birkmeyer JD, Finlayson EV, Birkmeyer CM. Volume standards for high-risk surgical procedures: potential benefits of the Leapfrog initiative. Surgery 2001;130:415e22. 9. Lapar DJ, Kron IL, Jones DR, Stukenborg GJ, Kozower BD. Hospital procedure volume should not be used as a measure of surgical quality. Ann Surg 2012;256(4):606e15. 10. Hertzer NR. Reasons why data from the nationwide inpatient sample can Be misleading for carotid endarterectomy and carotid stenting. Semin Vasc Surg 2012;25:13e7. 11. Khuri SF, Henderson WG. The case against volume as a measure of quality of surgical care. World J Surg 2005;29:1222e9. 12. Hollenbeak CS, Bowman AR, Harbaugh RE, Casale PN, Han D. The impact of surgical specialty on outcomes for carotid endarterectomy. J Surg Res 2010;159:595e602. 13. Modrall JG, Rosero EB, Chung J, Arko III FR, Valentine RJ, Clagett GP, et al. Defining the type of surgeon volume that influences the outcomes for open abdominal aortic aneurysm repair. J Vasc Surg 2011;54(6):1599e604. 14. Nazarian SM, Yenokyan G, Thompson RE, Griswold ME, Chang DC, Perler BA. Statistical modeling of the volumeoutcome effect for carotid endarterectomy for 10 years of a statewide database. J Vasc Surg 2008;48(2):343e50. 15. Charalampoudis P, Therasse A, Ferdin F. Carotid endarterectomy in a low volume vascular centre. Acta Chir Belg 2011;111:364e5. 16. Kurlansky PA, Argenziano M, Dunton R, Lancey R, Nast E, Stewart A, et al. Quality, not volume, determines outcome of coronary artery bypass surgery in a university- based community hospital network. J Thorac Cardiovasc Surg 2012;143(2):287e93. 17. Joanna TP, Carmody D, Power S, Corr A, Moroney J, Williams D, et al. Our Single-Centre experience of carotid artery stenting in high-risk patients over a 10-year period. EJMINT Original Article 15th November 2013;2013:1346000132.

Please cite this article in press as: Ali A, et al., The effect of carotid stenting on endarterectomy practice e A single institution experience, The Surgeon (2014), http://dx.doi.org/10.1016/j.surge.2014.04.001

The effect of carotid stenting on endarterectomy practice--A single institution experience.

The number of operations performed per surgeon is thought to determine the quality of carotid endarterectomy (CEA) surgery. The advent of carotid arte...
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