Perspectives

Commentary on:Reasons for Readmission After CarotidEndarterectomyby Rambachan et al. World Neurosurg 2013http://dx.doi.org/10.1016/j.wneu.2013.08.020

R. Loch Macdonald, M.D., Ph.D.

Professor of Surgery, University of TorontoKeenan Endowed Chair and Head

Division of Neurosurgery, St. Michael’s Hospital

Carotid Endarterectomy: Minimizing Unplanned Readmissions

Michael Tso and R. Loch Macdonald

therosclerosis at the common carotid artery bifurcation

leading to the development of thromboembolism and

A ipsilateral ischemic stroke was described in 1951 (6). In

1965, DeBakey reported being the first to perform carotid end-arterectomy (CEA) in 1953, although others have disputed this

and suggested that Crawford deserved this credit (12). Sincethen, CEA has been performed in patients with carotid stenosis

to prevent stroke and is one of the most studied surgical pro-cedures in history. More recently, carotid angioplasty and stent-

ing (CAS) has been performed as an alternative procedure forpatients with carotid stenosis. A large randomized controlled trial

has generated controversy over the indications for CEA and CASin preventing ischemic stroke, a debate that is beyond the scope

of this commentary (1).

Patients who are candidates for CEA may have significant med-

ical comorbidities, such as hypertension, diabetes, hyperlipid-emia, coronary artery disease, and peripheral vascular disease,

which increase the risk of complications and poor outcome (11).A more recent report has listed CEA as the surgical procedure

that has the third highest readmission rate in the United States,after colectomy and lower extremity bypass (8). Measures are

needed to minimize complications and readmissions not only toimprove the care for patients but also to minimize the costs to

the health care system.

In this issue of WORLD NEUROSURGERY, Rambachan et al. iden-tified preoperative and postoperative risk factors leading to

Key words- Carotid endarterectomy- Health policy- Hospital readmissions- Neurosurgery- Vascular surgery

Abbreviations and AcronymsCAS: Carotid angioplasty andstentingCEA: Carotid endarterectomyCREST: CarotidRevascularizationEndarterectomy vs. StentingTrialNSQIP: National SurgicalQuality Improvement Program

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unplanned 30-day readmission after CEA. They analyzed the Na-

tional Surgical Quality Improvement Program (NSQIP) databaseand identified 8456 patients who underwent CEA in 2011, 1 year

after the publication of the CREST (Carotid Revascularization End-arterectomy vs. Stenting Trial) results that established CEA as

having a lower stroke risk than CAS (1). This fact is importantbecause management strategies and practice patterns may have

changed after the publication of this landmark trial. The in-vestigators found that there was a 6.0% unplanned 30-day read-

mission rate after CEA. Among preoperative risk factors, older age,historyof stroke,diabetes, andpreoperativebleedingdisorderwere

found to predict readmission after CEA, although the odds ratios for

these risk factors were all<2. The investigators defined “bleedingdisorder” as having vitamin K deficiency, hemophilia, thrombocy-

topenia, or chronic anticoagulation. Among postoperative risk fac-tors, surgical site infection, postoperative myocardial infarction,

sepsis or septic shock, postoperative stroke, pneumonia, and uri-nary tract infection were found to predict readmission, with high

odds ratios ranging from 3.21e21.90. Rambachan et al. concludedthat these findings may help guide surgical decision making and

limit readmissions. How exactly to do this is a little less clearbecause achieving low complication rates after CEA is what we all

strive to do to achieve the best outcomes for our patients.

There are some questions about this study. Although the authorsfound that having a history of stroke before CEA may increase

the likelihood of having an unplanned readmission, it was unclearwhat proportion of patients in this database were symptomatic

Division of Neurosurgery, St. Michael’s Hospital, Labatt Family Centre ofExcellence in Brain Injury and Trauma Research, Keenan Research Centre of the

Li Ka Shing Knowledge Institute of St. Michael’s Hospital, and the Department of Surgery,University of Toronto, Toronto, Ontario, Canada

To whom correspondence should be addressed: R. Loch Macdonald, M.D., Ph.D.[E-mail: macdonaldlo@smh.ca]

Citation: World Neurosurg. (2014).http://dx.doi.org/10.1016/j.wneu.2013.10.049

www.WORLDNEUROSURGERY.org 1

PERSPECTIVES

(i.e., patients with retinal transient ischemic attack, hemispherictransient ischemic attack, or stroke). Coincidentally, an abstract

published by Curran et al. (2) also looked at predictors of 30-dayreadmission after CEA using the same NSQIP database and the

same target year of 2011. These investigators found that mostpatients in the database were asymptomatic (62%) and that the

30-day readmission rate was 7.5%, which likely included both

planned and unplanned readmissions (2). Also, symptomatic pa-tients had a significantly higher readmission rate compared with

asymptomatic patients (10% vs. 7%, P < 0.01). This findingmeans that a hospital or a surgeon treating a greater proportion

of symptomatic patients would have a higher readmission rate.When comparing readmission rates after CEA between hospi-

tals, regions, or countries, one must take into account the pro-portion of symptomatic patients treated. Many countries,

including Canada, the United Kingdom, and Australia, treat pro-portionally more symptomatic patients compared with the United

States (3, 9, 10). As a result, using the 6.0% unplanned read-mission from the NSQIP database, with a higher proportion of

asymptomatic patients, as a benchmark for other countries maynot be valid. Also, CAS may not be readily available in certain

regions or countries, leading to some patients undergoing CEAwith potentially higher risk of complications and readmission

(e.g., a patient with a contralateral carotid occlusion, a patientwith a very high carotid bifurcation). Readmission rates need to

be evaluated based on location and practice patterns.

One of the strengths of this study is having the opportunity to

analyze a large number of patients undergoing CEA with acomprehensive list of preoperative and postoperative factors

considered. The NSQIP employs trained surgical clinical reviewersto confirm data based on patient charts, which may be more

reliable than data based on insurance claims alone (7). The overall30-day stroke rate was 1.2%, which is below the CEA trial

benchmarks required for competency in treating asymptomaticpatients (<3%) and symptomatic patients (<5%) (1). This finding

is important, confirming that the efficacy and complication ratewithin the limits of a randomized controlled trial translate into

effectiveness in the less tightly controlled real world. However,not every patient in this database was assessed by a neurologist

or an expert in stroke diagnosis, and some strokes may have beenmissed, and the overall stroke rate may be an underestimate.

Limitations include not knowing if these postoperative complica-tions occurred during the hospital stay or after hospital discharge.

Also, the NSQIP collects data from many different surgical pro-cedures and does not record CEA-specific complications, such as

cranial nerve injury or cervical hematoma. This study does notrecord patients who returned to the hospital’s emergency

department but were not readmitted. Unnecessary emergencydepartment visits also contribute to increasing health care costs.

Better patient discharge information and access to an urgent

2 www.SCIENCEDIRECT.com WORLD NEU

follow-up clinic may limit the number of emergency departmentvisits. These strategies also may limit hospital readmissions.

How does this study help decrease readmission rates? The study

emphasizes that there are preoperative and postoperative riskfactors that lead to higher readmission rates. To decrease read-

missions, the goals would be to optimize the patient’s medicalstatus before CEA and to minimize complications after CEA.

Comorbidities such as diabetes and hypertension need to be wellcontrolled before surgery. Coagulation status also must be

assessed thoroughly with a management plan in place beforesurgery. We are sure most other centers routinely obtain cardiol-

ogy and internal medicine consultations before surgery in thesepatients. One must be careful not to interpret the goal in reducing

readmission rates as the encouragement of more operations onpatients with asymptomatic carotid stenosis or less comorbidity

burden, who have inherently lower risks of complications. Forpatients with asymptomatic carotid stenosis, it is even more

crucial that all comorbidities are well controlled before CEAbecause the periprocedural complication rate must be low for

there to be any benefit of surgery, and there is no reason toperform the procedure urgently. However, CEA for symptomatic

carotid stenosis generally should be performed within 2 weeks (5).

To minimize complications, it is important that the surgeon,

whether a vascular surgeon, general surgeon, cardiothoracicsurgeon, or neurosurgeon, be an expert in CEA with a compli-

cation rate consistent with current guidelines (1). Attaining thiscomplication rate can be challenging for surgeons early in their

career as well as surgeons who perform few CEAs because evena small number of complications are clinically, if not statistically,

significant. It may be helpful for new cerebrovascular surgeonsperforming CEA to have a more senior surgeon as a mentor who

is available to discuss cases. Keeping an ongoing personal record

or, better yet, a prospective institutional database of complica-tions and patient outcomes after CEA would help the surgeon

assess and improve on these outcomes. Also, hospital and sur-geon volume correlate inversely with complications, suggesting a

need for regional specialization in CEA (4). It is unclear whatannual number of CEA procedures performed is needed to

maintain competency, but the CREST investigators enrolled onlysurgeons with annual case volumes of >12 CEA procedures with

previously mentioned low complication rates (1).

Asmentioned previously, one potential solution to the readmission

issue is to avoid operating on patients with a given set of comor-bidities for the purposes of reducing readmission rates. Assuming a

patient would fulfill criteria for CEA, this solution would be inap-propriate. Perhaps patient data regarding preoperative and post-

operative risk factors and outcomes should continue to be collectedfor the sake of patient care and not because of impending payment

reductions for readmissions. Most patients would agree that beingreadmitted to the hospital is not their preference.

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