Trends and results of carotid artery surgery in Germany

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1 English version of Trends und Ergebnisse der Karotischirurgie in Deutschland Teil 1: klinische Stadien, perioperative Morbidität und Letalität sowie Bewertung der Qualitätsindikatoren Gefässchirurgie : ] DOI /s Springer-Verlag Berlin Heidelberg 2013 L. Deutsch 1 B. Haller 2 H. Söllner 1 M. Storck 3, 4 H.-H. Eckstein 1 1 Klinik und Poliklinik für Vaskuläre und Endovaskuläre Chirurgie, Klinikum Rechts der Isar, Technische Universität München, Munich 2 Institut für Medizinische Statistik und Epidemiologie, Technische Universität München, Munich 3 Klinik für Gefäß- und Thoraxchirurgie, Städtisches Klinikum Karlsruhe 4 Kommission für Qualität und Sicherheit, Deutsche Gesellschaft für Gefäßchirurgie und Gefäßmedizin (DGG) Trends and results of carotid artery surgery in Germany Part 1: clinical stages, perioperative morbidity and mortality and assessment of quality indicators Aim Despite substantial progress in the acute treatment of cerebral ischemia, stroke is still the second most common cause of death worldwide and the leading cause of long-term disability [15]. Between 20 and 30% of all cerebral ischemia is caused by stenosis of the internal carotid artery. In a meta-analysis, the prevalence of moderate carotid stenosis ( 50%) in people younger than 70 years was reported to be 4.8% for men and 2.2% for women. In persons who were 70 years, the prevalence was higher for both sexes at 12.5% for men and 6.9% for women [5]. The prevalence for highgrade carotid stenosis 70 was between 0 and 4.9% [5, 11]. Especially dangerous are unstable plaque stenoses, which significantly increase the risk of cerebral embolism [8, 12]. Although it has been shown in recent studies that plaque composition represents an important factor in the assessment of stroke probability [2], the following applies: D The degree of stenosis is the only indication criterion with the highest level of evidence for carotid endarterectomy. The recently published S3 guidelines for extracranial carotid stenosis and other national and international guidelines recommend considering carotid endarterectomy (CEA, [6, 10, 13, 14]) in patients with 60 99% asymptomatic carotid stenosis, because this significantly reduces their risk for stroke. A benefit of CEA in patients with asymptomatic carotid stenosis can only be achieved, if the complication rate is <3% [7]. For symptomatic carotid stenosis, CEA is the method of choice. In patients with 70 99% stenosis after a transient ischemic attack (TIA) or nondisabling stroke, CEA is recommended and should also be considered in patients with symptomatic stenosis of 50 69%. For stenoses <50%, CEA is not recommended [7]. Since 2002, all German hospitals are required to participate in the mandatory, external quality assurance (QA) registry for the reconstruction of carotid arteries. The federal office Quality Assurance ( Bundesgeschäftsstelle Qualitätssicherung ggmbh, BQS) was responsible for the registry until 2008 and since 2009 the Institute for Applied Quality Improvement and Research in Health Care ( Institut für angewandte Qualitätsförderung und Forschung im Gesundheitswesen GmbH, AQUA Institute), a professionally independent institution in accordance with 137a of the fifth book of the German social code book (SGB V) is responsible for the registry. The national reports contain data on all of the quality indices (QI) and various additional descriptive analyses (basic evaluation). At the time that the QA process was introduced, care deficits were suspected particularly in relation to the indication for surgery and related complications. Documentation for QA therefore focuses on the important cornerstones of the correct indications for carotid artery stenosis as well as periprocedural strokes and deaths. Thus, QI were defined and are shown in. Tab. 1. For the present study, the period from 2003 was used, because the 2002 report with approximately 15,000 documented CEA was still incomplete. The goal was to determine possible changes in the patient population, the surgical methods, and clinical results using the 9-year period. In part 1 of the article, changes in the patient population, the clinical stages (inclu ding Gefässchirurgie

2 Tab. 1 Definitions of the quality indices (QI) of the national quality assurance Carotid artery reconstruction used in this study Definition of the indicator Indication QI1 Stenosis grade 60% in asymptomatic carotid stenosis ( 85%) QI2 Stenosis grade 50% in symptomatic carotid stenosis ( 95%) Perioperative stroke or death QI3 In asymptomatic carotid stenosis I (without contralateral stenosis or >70% stenosis) QI4 In asymptomatic carotid stenosis II (with contralateral stenosis or >70% stenosis) QI5 In asymptomatic carotid stenosis I ( 70% stenosis) QI6 In asymptomatic carotid stenosis II (50 69% stenosis) QI8 Severe stroke or death (Rankin score: 4 6) Tab. 2 Modified Rankin scale for classification of the disability severity after a stroke Severity of the neurological disability Rankin 0 No neurological disability Rankin 1 No significant functional neurological disability Rankin 2 Slight functional disability Rankin 3 Moderately severe disability but can walk unassisted and/or moderately severe aphasia Rankin 4 Severe disability, walking only with assistance Rankin 5 Invalidating disability, patient bedridden or wheel chair dependent Rankin 6 Dead indications) and periprocedural morbidity and mortality are presented. In the upcoming part 2, trends concerning the perioperative diagnostics and treatment procedures are presented in detail. Patients and methods The annual reports from of the QA registry of the BQS and the AQUA institute were systematically evaluated. Patient-related parameters (e.g., age, sex, indication, and symptoms) were documented. The indication groups are listed in. Infobox 1. In particular, the predefined QI were statistically analyzed to assess the indications and perioperative complication rates. Changes in the patient population and in the treatment methods as well as trends in the perioperative morbidity and mortality in the individual groups of indications were examined. Carotid artery stenting (CAS) has only been part of carotid artery stenosis QA since 2012; thus, no evaluation could be made regarding this. Concerning the individual quality indicators, it is important to note that in contrast to the basic evaluation they may focus only on a selected part of the population. Logistic regression analysis was used in the risk-adjusted QI perioperative stroke or death (QI7 and QI8). QI7 (perioperative stroke or death-adjusted risk using logistic carotid artery score I) was not included in the evaluation, because no individual data were available and it did not seem likely that a statistically meaningful trend could be calculated. A detailed description of the QI, including the current calculation rules, is available in German at under Themen/Leistungsbereiche. The Rankin classification used for QI8 is shown in. Tab. 2. To improve comparability of cases, patients with aortic dissection and procedures where a transposition of the caro tid/ subclavian artery was performed were excluded starting in 2010 because the carotid artery was not the target organ. The cases excluded as reported in the 2010 national assessment were also excluded retrospectively from the 2009 results. The statistical evaluation was performed using Software R Version (R Foundation for Statistical Computing, Vienna, Austria) and SPSS Version Changes in the frequency distribution of binary variables over time were evaluated using the Cochran Armitage trend test. To assess the change in the median time between the last event and surgery during the observation period, the Pearson correlation coefficient was used. A 2-sided significance level of α=5% was selected for all tests performed. Results Patients From , 229,304 carotid endarterectomy procedures were documented. During the observation period, the median number of the participating hospitals was 520/year; the median number of documented cases was 25,858/year. The patient-related data and the distribution of indications for carotid endarterectomy over the investigated period are summarized in. Tab. 3. The mean patient age increased from 69 to 71 years from 2003 to In the years thereafter, the median and mean patient age were not determined.» The proportion of patients older than 80 years increased significantly in the period examined In the study period, the proportion of patients who were 80 years or older at the time of surgery increased significantly from 10.8 to 16.9% (p<0.001,. Fig. 1). The proportion of women was on average 32% and did not change significantly over the survey period. The proportion of patients with status 3 in the classification of the American Society of Anesthesiologists (ASA) rose from 60.4 to 69.5% (p<0.001), while the group of patients with high comorbidity (ASA status 4 5) remained constant. Indications The QI1 (proportion of patients with asymptomatic carotid stenosis 60%) and QI2 (proportion of patients with 50% symptomatic carotid stenosis) met the quality targets of 85% (QI1) and 90% (QI2), respectively, throughout the study period (. Fig. 2). The distribution of the indication groups also changed over the survey period. The proportion of asymptomatic patients (group A) increased significantly compared to the symptomatic patients (group B) and carotid endarterectomy under special conditions (group C) from 50.7 to 53.1% (. Tab. 3;. Fig. 3a c). In the 2 Gefässchirurgie

3 Abstract Zusammenfassung Gefässchirurgie : DOI /s Springer-Verlag Berlin Heidelberg 2013 L. Deutsch B. Haller H. Söllner M. Storck H.-H. Eckstein Trends and results of carotid artery surgery in Germany Part 1: clinical stages, perioperative morbidity and mortality and assessment of quality indicators Abstract Background. Since 2002 all German hospitals are required to participate in the mandatory quality assurance registry for reconstruction of extracranial carotid arteries. Aim. This article documents the changes in the patient population, the clinical stages and clinical results from 2003 to The analysis of preoperative diagnostics, operative methods and procedural management will be dealt with in part 2 of this publication. Material and methods. The annual quality assurance reports of the registry (BQS, AQUA Institute) from 2003 to 2011 were evaluated. Patient characteristics as well as predefined quality indices (QI) and perioperative morbidity and mortality were statistically analyzed. Results. A total of 229,304 carotid endarterectomies were reported (male 68%, female 32%). The proportion of patients >80 years increased significantly throughout the years (p<0.001). The mean rates of asymptomatic and symptomatic stenoses as well as operations under special conditions (Indication group C) were 53%, 34% and 13%, respectively. The QI1 (proportion of patients with 60% asymptomatic carotid stenosis) and QI2 (proportion of patients with 50% symptomatic carotid stenosis) met the quality targets of 85% (QI1) and 90% (QI2), respectively, throughout the time period evaluated. The rate of perioperative stroke or death in patients with asymptomatic stenosis was reduced from 2.0% in 2003 to 1.1% (without contralateral stenosis 70%) and from 2.9% to 2.1% (with contralateral stenosis 70%) and in symptomatic patients from 4.0% to 2.7% (stenosis 70%, p<0.001) and from 4.6% to 2.3% (50 69% stenosis, p<0.001). The median overall mortality was 0.9%. In symptomatic carotid stenosis there was a significant reduction in the interval between the neurological index event to the operation from 25 to 9 days (p<0.001, R= 0.97). Conclusion. Since the implementation of the mandatory national quality assurance system for operative carotid artery reconstruction a progressive decrease of perioperative morbidity could be shown. The interval between neurological index event and operation decreased significantly throughout the survey period and averaged 9 days in Keywords Carotid stenosis Carotid endarterectomy Vascular surgical procedures Stroke Quality assurance Trends und Ergebnisse der Karotischirurgie in Deutschland Teil 1: klinische Stadien, perioperative Morbidität und Letalität sowie Bewertung der Qualitätsindikatoren Zusammenfassung Hintergrund. Seit 2002 besteht für alle deutschen Krankenhäuser die Verpflichtung zur Teilnahme an der Qualitätssicherung (QS) für die operative extrakranielle Karotisrekonstruktion. Ziel der Arbeit. Veränderungen der Patientenpopulation, der klinischen Stadien und der klinischen Ergebnisse von sollten ermittelt werden. Die Analyse der präoperativen Diagnostik, der Operationsmethoden und des prozeduralen Managements folgt in einer späteren Publikation. Material und Methoden. Die Jahresberichte des QS-Registers wurden systematisch ausgewertet. Patientenbezogene Parameter und prädefinierte Qualitätsindikatoren wurden statistisch evaluiert (Cochran- Armitage-Trend-Test, Korrelationskoeffizient nach Pearson, 2-seitiges Signifikanzniveau von α=5%). Ergebnisse. Es wurden operative Karotisrekonstruktionen (männliche/weibliche Patienten 68/32%) dokumentiert. Der Anteil an über 80-jährigen Patienten stieg signifikant an (p<0,001). Die Anteile an asymptomatischen und symptomatischen Stenosen betrugen 53 resp. 34% ohne signifikante Veränderungen. Es erfolgten 13% der Karotisoperationen unter besonderen Bedingungen (Rezidiv-, Simultaneingriffe, Aneurysma). Der Anteil der Patienten mit einem Stenosegrad 60% bei asymptomatischer und 50% bei symptomatischer Stenose lag stets im Qualitätszielbereich von 85 resp. 90%. Die Rate an perioperativen Schlaganfällen/Tod bei Patienten mit asymptomatischer Stenose verringerte sich von 2,0% in 2003 auf 1,1% (ohne kontralaterale Stenose 70%) bzw. von 2,9% auf 2,1% (mit kontralateraler Stenose 70%) und bei symptomatischen Patienten von 4,0 auf 2,7% (Stenose 70%, p<0,001) resp. von 4,6 auf 2,3% (50- bis 69%ige Stenose, p<0,001). Die mediane perioperative Letalität blieb bei 0,9%. Bei symptomatischen Patienten zeigte sich eine signifikante Reduktion des Intervalls zwischen neurologischem Indikatorereignis und Operation von 25 auf 9 Tage (p<0,001). Schlussfolgerungen. Seit 2003 hat der Anteil der über 80-jährigen Patienten deutlich zugenommen. Gleichzeitig kam es zu einer schrittweisen Senkung der perioperativen Komplikationsraten. Das Intervall zwischen neurologischem Indikatorereignis und Operation konnte hochsignifikant auf zuletzt nur noch 9 Tage verkürzt werden. Schlüsselwörter Karotisstenose Karotisendarteriektomie Vaskuläre Operationsmethoden Schlaganfall Qualitätssicherung group of patients with symptomatic carotid stenosis, the proportion of patients with amaurosis fugax and TIA decreased significantly from 21.5 to 18.1% and from 45.5 to 36.1%, respectively (p<0.001). The group of patients with a previous stroke (Rankin score) increased significantly from 34.9 to 40.5% (. Tab. 3). In symptomatic carotid stenosis, a significant reduction in the interval between the neurological event and surgery from 25 to 9 days was observed (p<0.001, R= 0.97;. Fig. 4).» Interval between neurological event and surgery decreased from 25 to 9 days The emergency carotid endarterectomy rate rose significantly from 1.7 to 3.6% Gefässchirurgie

4 Infobox 1 Indication groups Indication group A: asymptomatic carotid artery stenosis Event free within the last 6 months (no new-onset focal neurological deficits in the ipsilateral region, not meant are aspects related to previous events) excluding carotid endarterectomy under special circumstances (Indication group C) Indication group B: symptomatic carotid artery stenosis, elective Relative frequency ,340 23,499 25,629 25,570 26,087 26,961 27,546 27,170 27,484 =n 10.9% 12.1% 12.8% 13.6% 14.8% 14.7% 15.3% 16.6% 16.9% 38.8% 39.9% 40.0% 40.6% 40.9% 40.6% 42.1% 43.1% 43.9% 36.3% 34.9% 34.7% 32.4% 31.3% 31.8% 29.6% 27.6% 26.5% Ipsilateral with: F amaurosis fugax F hemispheric TIA or F stroke within the last 6 months excluding carotid endarterectomy under special circumstances (Indication group C) Indication group C: carotid endarterectomy under special circumstances % % 12.5% 13.5% % 12.9% 13.0% 12.7% 12.7% years years years <60 years Fig. 1 8 Distribution of age groups over the observation period. Cochran Armitage trend test, p<0.001 F increasing TIA F acute, progressive stroke F aneurysm F coiling F combined carotid artery coronary surgery or combined carotid artery vascular surgery F certain plaque morphology characteristics with <50% stenosis (NASCET) for symptomatic carotid stenosis F transient lesions F relapse Relative freequency % 88.9% 98.7% 97.6% TIA transient ischemic attack, degree of stenosis based on NASCET ultrasound criteria for analysis of carotid artery stenosis from the North American Symptomatic Carotid Endarterectomy Trial. (p<0.001). Within this group, the proportion of patients with crescendo TIA decreased from 48.9 to 43.4% over the study period, while the proportion of patients with acute or progressive stroke rose from 35.6 to 56.1% (p<0.001;. Tab. 3). Perioperative morbidity and mortality The rate of perioperative stroke or death in patients with asymptomatic stenosis without contralateral stenosis (QI3) continuously decreased significantly from 2.0% in 2003 to 1.0% in The rate of perioperative stroke or death in patients with asymptomatic stenosis with contralateral stenosis (QI4) was on average 2.5% and did not change significantly over the survey period (. Fig. 5). For patients Year QI1 ( 60% asymptomatic carotid artery) QI2 ( 50% symptomatic carotid artery stenosis) Fig. 2 8 Percent (%) of patients with asymptomatic stenosis 60%, quality indicator 1 (QI1, red), and symptomatic stenosis 50%, quality indicator 2 (QI2, blue), target: QI1: 85%; QI2: 90% with symptomatic stenosis 70% (QI5), perioperative stroke or death decreased from 4.0 to 2.7% (p<0.001) and for patients with symptomatic stenosis of 50 69% (QI6), the rate decreased from 4.6 to 2.3% (p<0.001;. Fig. 6). The average overall morbidity in the form of severe stroke (Rankin score 4, 5) or death (QI8, 4 Gefässchirurgie

5 Tab. 3 Overview of the clinical data distribution Total p n % n % n % n % n % n % n % n % n % n % Age (years) < , < , , , , , , , , , > , Sex m 13, , , , , , , , , , f , ASA < , , , , , , , , , , , Indication group Symptoms (from B) A , , , , , , , , , <0.001 B , C , Amaurosis , <0.001 fugax Ipsilateral , hemispheric TIA Stroke with , Rankin 0 5 Other Emergency Total <0.001 Crescendo TIA Acute/ progressive stroke Other ASA 1 5 Classification of patients by the American Society of Anesthesiology into groups based on their physical condition, f female, m male, TIA transient ischemic attack. Gefässchirurgie

6 Tab. 4 Overview of complications Local complications Bleeding requiring reoperation Periferal nerve lesion Carotid artery occlusion Total p n % n % n % n % n % n % n % n % n % n % < General complications requiring treatment Total <0.001 DVT Pul mo- nary Cardiovascular <0.001 DVT Deep vein thrombosis.. Fig. 7) was 1.5%, but also significantly decreased from 1.7% in 2003 to 1.2% in 2011 (p<0.001). The average overall mortality of 0.9% remained constant over the survey period. Other perioperative complications A reduction was observed for all local complications (e.g., postoperative bleeding requiring surgery, peripheral nerve injury, and carotid artery occlusion). This is most obvious for peripheral nerve lesions (from 1.9 to 1.4%, p<0.001). The rate of general complications requiring treatment also decreased (from 3.9 to 3.7%, p<0.001). However, this is due to a decrease in the rate of cardiovascular complications (from 1.8 to 1.2%), since the rate of pulmonary complications and deep vein thrombosis (DVT) did not change over the survey period (. Tab. 4). Discussion Interpretation of results The present nationwide analysis of carotid endarterectomy over 9 years with a sample size of 229,304 patients is the largest published study on the development of the surgical treatment of carotid artery stenosis. Participation in the mandatory documentation was introduced by legislation; thus, the reported results fully represent the care situation in Germany. Because the percentage of completely evaluable data sets was continuously >98%, the data are to a large extent representative for the outcome of CEA in Germany. Only the international VASCUNET group ([18], subcommittee of the European Society of Vascular Surgery) recorded 48,185 CEA a similarly large number of cases, but all variables were documented only for less than half of cases. However, in this study, the completeness is questionable. Perhaps not all patients with perioperative strokes were included in the survey. In the present study, the proportion of women and the median age was equal to that in the international registry study of VASCUNET group [18]. Within the survey period, the proportion of patients who were 80 years or older at the time of surgery increased significantly in the study population. Although recent studies show only a small increased risk of surgery in patients over 80 years [16], it must be kept in mind that these patients only benefit from the prophylactic nature of the operation, when they have a correspondingly long life expectancy [4]. The overall comorbidity of patients has increased over the years and the number of patients with ASA status <3 has decreased. On the one hand, this may be because accompanying diseases are more carefully documented; on the other hand, this could be caused by the increasing proportion of very old patients. The distribution of indication groups did not change significantly over the survey period, but differs significantly from the indications observed in other countries. In the VASCUNET registry, 60.1% of patients were on average symptomatic [18], while in the present collective only 34.6% of patients were symptomatic and if the emergencies from group C are included 37.4%. However, a broad range between countries is also recorded in the international registry. For example, Italy reports 31.4% of patients being symptomatic, while Denmark reports 100%. The data obtained in this study also indicate that the indication group B patients 6 Gefässchirurgie

7 Relative frequency ,355 23,502 25,629 25,570 26,087 26,961 27,546 27,170 27,484 = n 14.3% 13.8% 13.8% 13.2% 13.2% 12.7% 12.3% 12.1% 11.9% 35.0% 34.4% 33.1% 35.3% 33.9% 34.6% 34.9% 35.2% 35.0% 50.7% 51.9% 53.1% 51.5% 52.9% 52.7% 52.8% 52.7% 53.1% Absolute frequency 25,000 20,000 15,000 10, Indication groups A Indication groups B C a A B C b 17,914 21,964 24,034 24,113 24,690 25,587 26,395 26,172 27,006 =n Relative frequency % 9.3% 26.7% 7.7% 14.7% 8.7% 26.6% 7.6% 14.7% 14.0% 8.6% 25.4% 6.9% 8.8% 27.3% 6.3% 14.0% 9.3% 25.3% 6.3% 12.1% 12.8% 12.6% 13.4% 2.6% 9.6% 9.2% 9.6% 32.5% 25.8% 26.5% 25.8% 6.2% 7.3% 6.1% 6.0% % 42.3% 44.3% 43.6% 45.1% 45.2% 45.6% 45.7% 45.4% c Carotid artery surgery under special conditions 70 % symptomatic stenosis 60 % asymptomatic carotid artery stenosis without contralateral stenosis or > 70% stenosis 50 60% symptomatic stenosis 60 % asymptomatic carotid artery stenosis with contralateral stenosis or >70 % stenosis Fig. 3 8 a,b Distribution of indication groups over the survey period (indication group A: asymptomatic carotid stenosis; indication group B: symptomatic carotid stenosis, elective indication group C: carotid endarterectomy under special conditions). c Distribution of the indication groups (classified according to the populations of the quality criteria QI3 QI6) over the survey period as follows: asymptomatic carotid stenosis I (without contralateral stenosis or >70% stenosis), asymptomatic carotid stenosis II (with contralateral stenosis or >70% stenosis), symptomatic carotid stenosis II ( 70%), and symptomatic carotid stenosis II (50 69%). Gefässchirurgie

8 Median interval between neurological event and carotid endarterectomy (days) days present more often with severe symptoms. The overall proportion of emergency carotid endarterectomies has also increased, as has the proportion of patients with acute or progressive stroke within this group. The increase in the number of acute stroke patients being treated is possibly due to improving interdisciplinary cooperation between vascular surgery and neurology, or stroke units, in combination with a broader availability of imaging techniques. Thus, treatment decisions could be accelerated. From the available data, it cannot be determined whether days Fig. 4 8 Interval between the neurological event in symptomatic carotid stenosis and surgery (days). Asterisk Pearson s correlation Relative frequency % 2.0% QI 3: p < 0.001, QI4: p =0.132* Perioperative stroke or death QI3: 60 % asymptomatic carotid artery stenosis without contralateral stenosis or > 70% stenosis QI4: 60 % asymptomatic carotid artery stenosis with contralateral stenosis or >70 % stenosis Year Fig. 5 8 Quality indicator 3 (QI3, red): perioperative stroke or death in asymptomatic carotid stenosis I (without contralateral stenosis or >70% stenosis) and quality indicator 4 (QI4, black): perioperative stroke or death in asymptomatic carotid stenosis II (with contralateral stenosis or >70% stenosis) 2.1% 1.1% this trend is equally distributed between hospitals or concentrated in the (university) centers. Another important factor is the preclinical time interval. A meta-analysis of 123 studies between 1987 and 2007 showed a decrease in the preclinical period after the onset of stroke symptoms, which is recorded in hours, of 6% per year [9]. This development is certainly a key factor for the clear decrease in the interval between the neurological event and surgery to 9 days. However, it also shows that the results of large trials for the treatment of symptomatic carotid artery stenosis, which recommend early surgery [17], are highly regarded in Germany. In order to improve the results further, referring physicians and the general public must be made more aware of the warning signs (TIA, amaurosis fugax) in order to reduce the preclinical period for patients with milder symptoms. The complication rate for asymptomatic carotid artery stenosis was significantly below the guideline target.» The complication rate for asymptomatic carotid stenosis was significantly below the guideline target The rate of perioperative stroke or death was significantly reduced in patients with asymptomatic stenosis without contralateral stenosis (QI3) and in patients with 50% symptomatic stenosis (QI4/QI5). In addition, the overall disease-specific morbidity such as severe strokes (Rankin 4, 5) or death (QI8) was significantly reduced. In particular, concerning asymptomatic carotid stenosis, the decrease of the complication rate from 2.0 to 1.0% in the overall survey period was well below the guideline target of 3% [7]. In international comparison, the rate of perioperative stroke or death in this group was also low. In a Cochrane systematic review on CEA for asymptomatic stenosis, the perioperative risk for this endpoint was 2.9% [3]. The overall higher morbidity in symptomatic stenosis is expected and is also reported in international studies [17]. Only the average overall mortality of 0.9% remained constant over the survey period. Encouraging is the decrease in the rate of peripheral nerve damage and cardiovascular events in the study period in the survey group presented. The average cardiovascular morbidity of 1.6% is low, compared to the results of the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST, [1]). Limitations The evaluation of the national report provides an overview of a very large collective. However, since no individual data 8 Gefässchirurgie

9 Relative frequency Relative frequency % 4.0% QI 5/6: p<0.001* % QI8: p < 0.001* are available, a correlation of morbidity and mortality on the individual risk factors and treatment modalities cannot be made. Future efforts should include an evaluation of the raw data in cooperation with the Kommission für Qualität und Sicherheit der Deutschen Gesellschaft für Gefäßchirurgie und Gefäßmedizin Gesellschaft für operative, endovaskuläre und präventive Gefäßmedizin (DGG) and the responsible federal agency. Year Perioperative stroke or death QI8: severe stroke or death (Rankin 4-6) 1.3% Fig. 7 8 Quality indicator 8 (QI8): severe stroke (Rankin score 4 6) or death in the total population. Asterisk Cochran Armitage trend test Year Perioperative stroke or death QI5: 70 % symptomatic stenosis QI6: 50 60% symptomatic stenosis 2.3% 2.7% Fig. 6 8 Quality indicator 5 (QI5, yellow): perioperative stroke or death in symptomatic carotid stenosis I ( 70%) and quality indicator 6 (QI6, green): perioperative stroke or death in symptomatic carotid stenosis II (50 69%). Asterisk Cochran Armitage trend test Since no follow-up visits are documented, no statements can be made about long-term results not even for 30-day outcome as stated in most publications. The validity of the data is dependent on the accuracy of data acquisition of those responsible at the participating clinics. The patients are mostly pre- and postoperatively evaluated by an independent neurological department. The final documentation is, however, submitted by the operating department. As discussed in detail in the part 2 of this study, an objective neurological investigation is generally performed in every patient by extradepartmental professionals in an increasing number of cases; nevertheless, an external control of the documentation does not occur. However, sampling is performed and in the case of abnormalities a so-called structured dialogue is requested. The variables studied were subject to fundamental changes over the survey period. For example, the populations of QI changed, the age groups re-distributed, the ultrasound criteria adjusted to the criteria of the German Society for Ultrasound in Medicine (DEGUM), and several parameters were not evaluated for the entire period. This makes it more difficult to compare data over the years. Conclusion F The presented data clearly demonstrate that there has been a gradual reduction in the perioperative complication rate since the introduction of mandatory QA. F There is a trend toward eversion endarterectomy and surgery under locoregional anesthesia. F The interval between the neurological event and surgery was only 9 days in the case of symptomatic carotid stenosis, which is also very low in international comparison. F The CAS data collected since 2012 will be analyzed in subsequent studies. F In the future, inclusion of the 30-day follow-up data would be desirable. Corresponding address Prof. Dr. H.-H. Eckstein Klinik und Poliklinik für Vaskuläre und Endovaskuläre Chirurgie, Klinikum Rechts der Isar, Technische Universität München Ismaninger Str. 22, Munich Germany hheckstein@web.de Gefässchirurgie

10 Compliance with ethical guidelines Conflict of interest. L. Deutsch, B. Haller, H. Söllner, M. Storck, and H-H. Eckstein state that there are no conflicts of interest. The accompanying manuscript does not include studies on humans or animals. References 1. Brott TG, Hobson RW 2nd, Howard G et al (2010) Stenting versus endarterectomy for treatment of carotid-artery stenosis. N Engl J Med 363: Chalela JA (2009) Evaluating the carotid plaque: going beyond stenosis. Cerebrovasc Dis 27(Suppl 1): Chambers BR, Donnan GA (2005) Carotid endarterectomy for asymptomatic carotid stenosis. Cochrane Database Syst Rev CD De Rango P, Lenti M, Simonte G et al (2012) No benefit from carotid intervention in fatal stroke prevention for >80-year-old patients. Eur J Vasc Endovasc Surg 44: Weerd M de, Greving JP, Hedblad B et al (2010) Prevalence of asymptomatic carotid artery stenosis in the general population: an individual participant data meta-analysis. Stroke 41: Demirel S, Attigah N, Bruijnen H et al (2012) Multicenter experience on eversion versus conventional carotid endarterectomy in symptomatic carotid artery stenosis: observations from the stent-protected angioplasty versus carotid endarterectomy (Space-1) trial. Stroke 43: Eckstein H-H, Kühnl A, Berkefeld J et al (2012) S3- Leitlinie zur Diagnostik, Therapie und Nachsorge der extracraniellen Carotisstenose. Gefässchirurgie 17(6) 8. Eckstein HH, Heider P, Wolf O et al (2004) Controversies in the treatment of carotid stenoses. Present state of research and evidence-based medicine. Chirurg 75: Evenson KR, Foraker RE, Morris DL, Rosamond WD (2009) A comprehensive review of prehospital and in-hospital delay times in acute stroke care. Int J Stroke 4: Goldstein LB, Adams R, Alberts MJ et al (2006) Primary prevention of ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council: cosponsored by the Atherosclerotic Peripheral Vascular Disease Interdisciplinary Working Group; Cardiovascular Nursing Council; Clinical Cardiology Council; Nutrition, Physical Activity, and Metabolism Council; and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation 113:e873 e Hill AB (1998) Should patients be screened for asymptomatic carotid artery stenosis? Can J Surg 41: Kolominsky-Rabas PL, Heuschmann PU, Marschall D et al (2006) Lifetime cost of ischemic stroke in Germany: results and national projections from a population-based stroke registry: the Erlangen Stroke Project. Stroke 37: Liapis CD, Bell PR, Mikhailidis D et al (2009) ESVS guidelines. Invasive treatment for carotid stenosis: indications, techniques. Eur J Vasc Endovasc Surg 37: Lindsay P, Bayley M, McDonald A et al (2008) Toward a more effective approach to stroke: Canadian best practice recommendations for stroke care. CMAJ 178: Lopez AD, Mathers CD, Ezzati M et al (2006) Global and regional burden of disease and risk factors, 2001: systematic analysis of population health data. Lancet 367: Miller MT, Comerota AJ, Tzilinis A et al (2005) Carotid endarterectomy in octogenarians: does increased age indicate high risk?. J Vasc Surg 41: Rothwell PM, Eliasziw M, Gutnikov SA et al (2003) Analysis of pooled data from the randomised controlled trials of endarterectomy for symptomatic carotid stenosis. Lancet 361: Vikatmaa P, Mitchell D, Jensen LP et al (2012) Variation in clinical practice in carotid surgery in nine countries Lessons from VAS- CUNET and recommendations for the future of national clinical audit. Eur J Vasc Endovasc Surg 44: Gefässchirurgie