Tongdu Tiaoshen acupuncture combined with carotid endarterectomy for carotid artery stenosis: a randomized controlled trial / 中国针灸

OBJECTIVE@#To observe the clinical therapeutic effect of Tongdu Tiaoshen acupuncture combined with carotid endarterectomy (CEA) and simple CEA on carotid artery stenosis (CAS).@*METHODS@#A total of 60 patients with CAS were randomized into an observation group (30 cases, 2 cases dropped off) and a control group (30 cases, 3 cases dropped off). Both groups were treated with eversion CEA (eCEA). The conventional treatment of internal medicine and antiplatelet drugs i.e. aspirin enteric-coated tablet and clopidogrel hydrogen sulfate tablet were given in the control group for 4 weeks. On the basis of the treatment in the control group, Tongdu Tiaoshen acupuncture was applied at Baihui (GV 20), Fengfu (GV 16), Yamen (GV 15), cervical Jiaji (EX-B 2), Dazhui (GV 14), etc. in the observation group, once a day, 1-day rest was taken after 6-day treatment, 2 weeks were as one course and totally 2 courses were required. The carotid intima-media thickness (IMT) before and after treatment was detected by ultrasonic diagnostic apparatus, the TCM symptom score was compared before and after treatment and in the follow-up of 6 months after treatment, the clinical efficacy was evaluated in the two groups. The occurrence of endpoints within 1 year was recorded.@*RESULTS@#After treatment, the carotid IMT and TCM symptom scores were decreased compared before treatment in the both groups (P<0.05), and the changes in the observation group were greater than the control group (P<0.05). In the follow-up, the TCM symptom scores were decreased compared before treatment in the both groups (P<0.05). The total effective rate was 96.4% (27/28) in the observation group, which was superior to 88.9% (24/27) in the control group (P<0.05). There were 1 case of stoke in the observation group and 2 cases of stroke in the control group within 1-year follow-up, and there was no significant difference in the number of endpoints between the two groups within 1 year (P>0.05).@*CONCLUSION@#Tongdu Tiaoshen acupuncture combined with CEA can effectively reduce the IMT in patients with CAS, improve the TCM symptom score, the efficacy is superior to simple CEA treatment.

Carotid angioplasty in diabetic patients carriers of critical carotid stenosis. Experience in a hospital in Mexico; results and six-month follow-up / Angioplastia carotídea en pacientes diabéticos portadores de estenosis carotídea crítica. Experiencia en un hospital en México; resultados y seguimiento a seis meses

Abstract: Objective: To evaluate the impact of diabetic status on outcome of patients undergoing carotid artery stenting (CAS). Background: Diabetes has been demonstrated to be a strong predictor of adverse outcome in patients undergoing coronary revascularization. Its significance in predicting outcome of patients undergoing carotid interventions has not been ascertained. Methods: This research is an observational, retrospective, comparative, descriptive study. Results: 279/341 patients/lesions were evaluated for carotid stenosis undergoing stenting. Non-diabetics versus diabetics were compared. Of the diabetic group, 59.5% were men, mostly hypertensive and with hypercholesterolemia. More than 40% of both groups had a prior percutaneous coronary intervention (PCI), 68.2% were asymptomatic and a half was high risk, greater comorbidity in the diabetic group with an EuroSCORE > 3, 46 vs 21.4% p = 0.000. No statistically significant difference was found in terms of major adverse cardiovascular events (MACE) at 30 days and accumulated six months in the non-diabetic group (non-DM) versus the diabetic (DM): nine patients (5.4%) versus eight (4.8%), p = 0.756 OR, 95% CI 0.857 (0.322-2.27) and 14 (8.3%) versus nine (5.3%), p = 0.249 OR, 95% CI 0.604 (0254-1435), respectively. Diabetic patients treated with carotid stent who underwent cardiovascular surgery showed a higher intrahospitalary mortality (4.6 vs 0.6%, p = 0.02). There was a higher rate of restenosis (1.9 vs 0%, p = 0.077) in non-diabetic patients. An increased incidence of TIA (transient ischemic attack) was observed in diabetic patients (8.7 vs 3.6%, p = 0.05). Conclusion: Diabetics undergoing CAS are more likely to have associated co-morbidities. However despite this handicap, their short term outcome after CAS is similar to that of non diabetics. Endovascular treatment of carotid stenosis may be a good alternative to surgical treatment.(AU)

Resumen: Objetivo: Evaluar el impacto del estado diabético sobre el resultado de los pacientes que se someten a la colocación de stents en la arteria carótida (CAS). Antecedentes: Se ha demostrado que la diabetes es un fuerte predictor de resultados adversos en pacientes sometidos a revascularización coronaria. No se ha determinado su importancia para predecir el resultado de los pacientes que se someten a intervenciones carotídeas. Métodos: Esta investigación es un estudio observacional, retrospectivo, comparativo y descriptivo. Resultados: Se evaluaron 279/341 pacientes/lesiones para la estenosis carotídea sometida a colocación de stents. Se compararon los no diabéticos versus los diabéticos. Del grupo diabético, 59.5% fueron hombres, la mayoría hipertensos y con hipercolesterolemia. Más del 40% de ambos grupos tuvieron una intervención coronaria percutánea (ICP) previa, el 68.2% fueron asintomáticos y la mitad de ellos de alto riesgo, mayor comorbilidad en el grupo diabético con un EuroSCORE > 3, 46 vs 21.4% p = 0.000. No se encontraron diferencias estadísticamente significativas en cuanto a los eventos cardiovasculares adversos mayores (MACE) a los 30 días y acumulados a los seis meses en el grupo no diabético (no DM) versus diabético (DM): nueve pacientes (5.4%) versus ocho (4.8%), p = 0.756 OR; IC 95%: 0.857 (0.322-2.27) y 14 (8.3%) versus nueve (5.3%), p = 0.249 OR; IC 95%: 0.604 (0254-1435), respectivamente. Los pacientes diabéticos tratados con endoprótesis carotídea sometidos a cirugía cardiovascular mostraron una mortalidad intrahospitalaria mayor (4.6 vs 0.6%, p = 0.02). Hubo una mayor tasa de reestenosis (1.9 vs 0%, p = 0.077) en pacientes no diabéticos. Se observó una mayor incidencia de AIT (ataque isquémico transitorio) en pacientes diabéticos (8.7 vs 3.6%, p = 0.05). Conclusión: Los diabéticos que se someten a la CAS son más propensos a tener comorbilidades asociadas. Sin embargo, a pesar de esta desventaja, su resultado a corto plazo después del CAS es similar al de los no diabéticos. El tratamiento endovascular de la estenosis carotídea puede ser una buena alternativa al tratamiento quirúrgico.(AU)

Estenose de carótida extracraniana: revisão baseada em evidências / Extracranial carotid stenosis: evidence based review

RESUMO A doença vascular cerebral extracraniana é uma das mais importantes causas de morte e de incapacidade em todo o mundo e seu tratamento se baseia em estratégias clínica e cirúrgica, sendo que esta última pode ser feita pelas técnicas convencional ou endovascular. O manejo da estenose da bifurcação carotídea visa principalmente a prevenir o acidente vascular cerebral e tem sido objeto de extensa investigação. O papel do tratamento clínico tem sido re-enfatizado, mas a endarterectomia de carótida permanece como o tratamento de primeira linha para pacientes sintomáticos com estenose de 50% a 99% e, para pacientes assintomáticos, com estenose de 60% a 99%. A angioplastia com stent é reservada para pacientes sintomáticos, com estenose de 50% a 99% e com risco elevado para a cirurgia aberta, por motivos anatômicos ou clínicos. Atualmente, o procedimento endovascular não é recomendado para pacientes assintomáticos que tenham condições de serem submetidos ao tratamento cirúrgico convencional. O Brasil apresenta tendência semelhante à de outros países da América do Norte e Europa, observando a manutenção da endarterectomia como a principal indicação para o tratamento da estenose carotídea e reservando o procedimento endovascular para casos em que há contraindicações para a primeira intervenção. Todavia, temos de melhorar os nossos resultados, reduzindo as complicações, notadamente a taxa de mortalidade geral.

ABSTRACT Extracranial cerebrovascular disease is one of the most important causes of death and disability worldwide and its treatment is based on clinical and surgical strategies, the latter being performed by conventional or endovascular techniques. The management of stenosis of the carotid bifurcation is mainly aimed at preventing stroke and has been the subject of extensive investigation. The role of clinical treatment has been re-emphasized, but carotid endarterectomy remains the first-line treatment for symptomatic patients with 50% to 99% stenosis and for asymptomatic patients with 60% to 99% stenosis. Stent angioplasty is reserved for symptomatic patients with stenosis of 50% to 99% and at high risk for open surgery due to anatomical or clinical reasons. Currently, the endovascular procedure is not recommended for asymptomatic patients who are able to undergo conventional surgical treatment. Brazil presents a trend similar to that of other countries in North America and Europe, keeping endarterectomy as the main indication for the treatment of carotid stenosis and reserving the endovascular procedure for cases in which there are contraindications for the first intervention. However, we must improve our results by reducing complications, notably the overall mortality rate.

Hidrocortisona reduz as concentrações séricas dos biomarcadores inflamatórios séricos em pacientes submetidos a endarterectomia de carótida / Hydrocortisone reduces serum concentrations of inflammatory biomarkers in patients subjected to carotid endarterectomy

A hidrocortisona pode reduzir a concentração dos biomarcadores inflamatórios séricos e teciduais.ObjetivoAnalisar a atividade inflamatória da proteína C-reativa ultrassensível (PCR-US), do fator de necrose tumoral (FNT)-alfa e do fator de crescimento do endotélio vascular (FCEV) séricos e teciduais, mediante administração intraoperatória de hidrocortisona, após endarterectomia de artéria carótida (EAC).MétodoVinte e dois pacientes foram divididos em Grupo Controle (5 assintomáticos e 6 sintomáticos) – não foi administrada hidrocortisona – e Grupo 1 (4 assintomáticos e 7 sintomáticos) – foram administrados 500 mg intravenoso de hidrocortisona. O PCR-US, o FNT-alfa e o FCEV séricos foram dosados no pré-operatório e em 1 hora, 6 horas e 24 horas após a EAC. Na placa carotídea, mensuramos os níveis de FNT-alfa e FCEV.ResultadosO grupo 1 exibiu menor concentração sérica de FNT-alfa em 1 hora (p=0,031), 6 horas (p=0,015) e 24 horas (p=0,017) após a EAC, e menor concentração de FCEV em 1 hora (p=0,006) e 6 horas (p=0,005) após a EAC, em relação ao grupo controle. Os pacientes sintomáticos do grupo 1 exibiram menor concentração de FNT-alfa em 1 hora e 6 horas após a EAC, e menor concentração de FCEV em 1 hora após a EAC, em relação ao grupo controle. Não houve diferença estatística entre as concentrações teciduais de FNT-alfa e FCEV entre o grupo controle e o grupo 1.ConclusãoA hidrocortisona reduz as concentrações séricas pós-operatórias de FNT-alfa e FCEV, em especial nos sintomáticos; porém, não reduz os níveis teciduais destes biomarcadores.

Hydrocortisone may reduce serum and tissue concentrations of inflammatory biomarkers.ObjectiveTo analyze the inflammatory activity of serum and tissue high-sensitivity C-reactive protein (hsCRP), tumor necrosis factor (TNF)-á and vascular endothelial growth factor (VEGF) after intraoperative administration of hydrocortisone, after carotid endarterectomy (CEA).MethodTwenty-two patients were allocated to a Control Group (5 asymptomatic and 6 symptomatic patients) and were not administered hydrocortisone or to Group 1 (4 asymptomatic and 7 symptomatic patients) and were administered 500 mg intravenous hydrocortisone. Serum levels of hsCRP, TNF-á and VEGF were tested for the preoperative period and at 1 hour, 6 hours and 24 hours after CEA. Levels of TNF-á and VEGF were also measured in carotid plaques.ResultsGroup 1 exhibited lower concentrations of serum TNF-á at 1 hour (p=0.031), 6 hours (p=0.015) and 24 hours (p=0.017) after CEA and lower concentrations of serum VEGF at 1 hour (p=0.006) and 6 hours (p=0.005) after CEA, relative to controls. Symptomatic patients in group 1 exhibited lower concentrations than controls for serum TNF-á at 1 hour and 6 hours after CEA and lower concentrations than controls for serum VEGF at 1 hour after CEA. There were no statistical differences in tissue concentrations of TNF-á or VEGF between the control group and group 1.ConclusionHydrocortisone reduces postoperative concentrations of serum TNF-á and VEGF, especially in symptomatic patients; but does not reduce tissue levels of these biomarkers.

The impact of carotid revascularization on cognitive function / O impacto da revascularização carotídea sobre a função cognitiva

The concept that carotid disease may compromise cognitive function was initially proposed by Fisher in 1951, based on an autopsy case. However, some topics involving cognitive function remain controversial, such as its correlation with carotid obstructive disease. So, the authors of this review evaluate the impact of carotid revascularization on cognitive function and the repercussions of the revascularization technique (carotid stenting vs. endarterectomy) chosen. It was clear from the literature reviewed that carotid stenosis is related to a decline in cognitive function over time. However, controversy still remains over the impact of carotid revascularization on cognitive function. With elation to the technique employed (carotid stenting vs. endarterectomy), the majority of studies found no difference between the two techniques in terms of overall cognitive outcome...

A noção de que a doença carotídea pode comprometer a função cognitiva foi proposta inicialmente por Fisher, em 1951, baseado em um caso de necropsia. Porém, alguns tópicos envolvendo a função cognitiva permanecem controversos, tais como sua correlação com a doença obstrutiva da carótida. Nesse sentido, os autores desta revisão buscam avaliar o impacto da revascularização carotídea e a repercussão da técnica de revascularização empregada (endarterectomia versus angioplastia carotídea) sobre a função cognitiva. A partir da literatura levantada, ficou claro que as estenoses carotídeas estão relacionadas com o declínio cognitivo ao longo do tempo, mas ainda há controvérsia no que se refere ao impacto da revascularização carotídea sobre a função cognitiva. Quanto à técnica empregada (angioplastia versus endarterectomia carotídeas), a maioria dos estudos não demonstrou distinção entre as duas técnicas quanto ao desfecho cognitivo geral...

Persistence of a hypoglossal artery: case report / Persistência da artéria hipoglossa: relato de caso

The authors present a case of persistent hypoglossal artery. Persistent hypoglossal artery is the second most common carotid-basilar anastomosis with a frequency of 0.02% to 0.09% and it can be associated with cerebrovascular disease. Diagnosis is by imaging methods and angiotomography is the method most often employed...

Os autores apresentam o caso de persistência da artéria hipoglossa. A artéria hipoglossa é a segunda anastomose carótida-basilar mais comum, com frequência de 0,02% a 0,09%, podendo estar associada a doenças vasculares cerebrais. Seu diagnóstico se faz através de métodos de imagem, sendo a angiotomografia o método mais utilizado...

Postoperative determination of the degree of carotid artery stenosis / Determinação pós-operatória do grau de estenose na artéria carótida

This article describes the VascMorph 1a prototype software and reports first results obtained with postoperative determination of the degree of stenosis in the carotid artery.

Este artigo descreve o programa protótipo VascMorph 1a e apresenta os primeiros resultados obtidos com a determinação pós-operatória do grau de estenose na artéria carótida.

Resultados del tratamiento endovascular de la patología carotídea en el Hospital San Juan de Dios de enero 2007 a febrero 2010 / Results of endovascular management of carotid disease at San Juan de Dios Hospital from January 2007 to February 2010

Justificación y objetivo: Determinar la morbi-mortalidad de los pacientes con enfermedad carotídea tratados por medio de stent en el Hospital San Juan de Dios, Costa Rica; de Enero 2007 a Febrero 2010. Métodos: Se realizó un registro retrospectivo observacional de los pacientes con Enfermedad Carotídea durante 13 meses en nuestro instituto. Basado en la información obtenida de los expedientes clínicos, dos subgrupos fueron identificados: pacientes sintomáticos y asintomáticos. Los factores de riesgo, escala ABCD2, territorio cerebral afectado, medidas de severidad de lesión no-invasiva e invasivas, tamaño de stents y finalmente complicaciones peri-operatorias, fueron investigadas y evaluadas. Resultados: 76 pacientes fueron identificados en nuestra serie, 87 por ciento,( n= 66/76), sintomáticos y 13 por ciento, (n = 10/76), asintomáticos. La hipertensión arterial fue el factor de riesgo más frecuente, seguido por el tabaquismo. Se evidenció una sub-estimación de la severidad de la lesión en los ultrasonidos diagnósticos en 24 por ciento, (n= 18/76), de los pacientes. Durante el procedimiento, se documentó predilatación de la lesión en 55 por ciento,( n= 42/76), de los pacientes y los stents más frecuentemente utilizados fueron de 7x30mm y 8x30mm representando un 47 por ciento, (n= 36/76), de los casos. La morbilidad neurológica de los pacientes asintomáticos fue del 0 por ciento y en el subgrupo de pacientes sintomáticos fue del 3 por ciento, 2/66. Conclusión: La terapia endovascular demostró ser una técnica segura y efectiva para la revascularización carotídea. Series más numerosas de pacientes deberían ser investigadas para adquirir mayor significancia estadística.

Manejo actual de la estenosis de carótida: tratamiento endovascular comparado con endarterectomía / Current management of carotid stenosis: endovascular treatment versus endarterectomy

Antiplatelet therapy used to be the only way to prevent further cerebrovascular events in patients with carotid stenosis. After publication of final results of the European Carotid Surgery Trial (ECST) and North American Symptomatic Carotid Endarterectomy Trial (NASCET), endarterectomy was considered the best treatment option. Currently, endovascular treatment of atherosclerotic carotid artery stenosis has been established as an alternative to surgical endarterectomy. Our aim is to show the evolution of endovascular therapy in carotid stenosis, to compare outcomes between endovascular, medical and surgical treatments, and to analize the current state of endovascular therapy. It is worth underscoring that many of the studies were conducted decades ago and consequently both the endovascular technique and medical treatments used then greatly differ from current practices. Several studies agree stenting benefits patients under 70 years of age and exhibits, at least, same short-term results as endarterectomy, along with higher rate of long-term restenosis. Indication for treatment in asymptomatic patients and the use of protection systems remain an unresolved issue. A multidisciplinary team should implement an individualized treatment plan for each patient.

En estenosis carotidea, la única manera de prevenir nuevos eventos cerebrovasculares era mediante antiagregación. Después de los estudios NASCET y ECST se estableció que la endarterectomía conseguía mejores resultados. Ahora se ha establecido la terapia endovascular como alternativa. Nuestro objetivo es mostrar la evolución de la terapia endovascular en estenosis carotidea, contrastar los resultados entre tratamiento endovascular, médico y quirúrgico y exponer la situación actual de la terapia endovascular. Algunos estudios se realizaron hace décadas y tanto la técnica endovascular como los tratamientos médicos, no son comparables con los de hoy. Varios estudios coinciden en que el stenting beneficia a menores de 70 años y presenta al menos iguales resultados que la endarterectomía a corto plazo, con mayor tasa de reestenosis a largo plazo. Quedan por resolver la indicación de tratamiento en pacientes asintomáticos o la utilización de sistemas de protección. El tratamiento debe ser individualizado en un equipo multidisciplinar.

Carotid artery surgery: back to the future: [review] / Cirurgia de artéria carótida: de volta para o futuro: [revisão]

In this study we performed 548 carotid revascularizations between 2006 and 2008 at the Department of Vascular Surgery of the A.Z. Sint-Blasius, Dendermonde, Belgium - a high-volume experienced center for carotid artery stenting (CAS). In 2006, our 30-day complication rates were 3.21 and 1.51 percent for symptomatic and asymptomatic patients, respectively. At that time, CAS represented approximately 86 percent of all cases we performed. However, the publication of the results of EVA-3S and SPACE studies drove us to reconsider our treatment allocation algorithm. In 2007 and 2008, CAS procedures only accounted for 43 percent of all carotid procedures, which was a result of strict patient selection with comorbidities and high-risk lesions assessment, especially in symptomatic patients. Our current 30-day stroke/death rates are 1.24 percent for symptomatic patients and 0.53 percent for asymptomatic ones, which reflects that correct patient selection is the key to maintain CAS as a valuable alternative to carotid endarterectomy.

Neste estudo, realizamos 548 revascularizações carotídeas entre 2006 e 2008 no Departamento de Cirurgia Vascular do A.Z. Sint-Blasius, Dendermonde, Bélgica - um centro de grande porte com experiência em angioplastia com stent de carótida (CAS, do inglês carotid artery stenting). Em 2006, nossas taxas de complicação em 30 dias foram de 3,21 e 1,51 por cento para pacientes sintomáticos e assintomáticos, respectivamente. Àquela época, a CAS representava aproximadamente 86 por cento de todos os casos realizados; entretanto, a publicação dos resultados dos estudos EVA-3S e SPACE nos levaram a reconsiderar nosso algoritmo de tratamento. Em 2007 e 2008, os procedimentos de CAS representaram apenas 43 por cento de todos os procedimentos carotídeos, o que foi resultado da seleção rigorosa de pacientes com avaliação de comorbidades e das lesões de alto risco, especialmente em pacientes sintomáticos. Nossas taxas atuais de AVE/óbito em 30 dias são de 1,24 por cento para pacientes sintomáticos e de 0,53 por cento para assintomáticos, refletindo que a seleção correta de pacientes é a chave para manter a CAS como uma alternativa válida à endarterectomia carotídea.

In-stent restenosis of innominate artery with critical stenosis of right internal carotid artery

A lady with aortitis syndrome developed in-stent restenosis [ISR] of the innominate artery stent and critical stenosis of right internal carotid artery. The therapeutic challenge was gaining access to the carotid vessel, after treating the innominate artery ISR and all the while using distal protection to circumvent potential cerebral embolism. Percutaneous transluminal angioplasty [PTA] with or without stenting is a safe therapeutic option for re-vascularization of the supra aortic vessels. In the event of re-stenosis, re-treatment with PTA and stenting is safe. Ample evidence-base exists now for carotid artery stenting [CAS] in preference to carotid endarterectomy in patients with stenotic lesions of the carotid vessels

Simulation based medical treatment of arteriosclerosis

To study the usefulness of computer simulations in planning effective treatment of stenosed carotid arteries. Computational study of poststenotic areas of carotid arteries. This study was carried out at the Department of Chemical Engineering, NED University of Engineering and Technology, Karachi from 15[th] April 2006 till date. Geometric model of stenosed carotid artery with 75% stenosis was developed on Computational Software Gambit 2.0/Fluent 6.2 and important factors such as recirculations, low and high shear forces on wall, vortex formation etc. were analyzed, which are important to the formation and rupture of plaque. For 75% stenosis, it was found that in the post-stenotic region the recirculation existed suggesting increased area of low shear stress and thus further deposition of plaque. High shear forces were observed at the throat of stenoses indicating higher probability for plaque to rupture. The preliminary,results from computer simulations matched well with the in-vitro experimental data indicating that computer simulations could revolutionize the medical treatment of stenosed carotid arteries

Indicações e resultados das intervenções percutâneas em artérias carótidas / Indication and results of percutaneous interventions in carotid arteries

Neste artigo os autores discutem a importância epidemiológica da doença oclusiva das carótidas, destacando a apresentação clínica e os principais métodos para o seu diagnóstico, invasivos ou não. Além disso, discutem os principais estudos disponíveis na literatura comparando os resultados da endarterectomia carotídea aos das intervenções percutâneas.

In this article, the authors discuss the epidemiological importance of carotid o cclusivedisease, highlighting the clinical presentation and the main methods for its diagnosis, both invasive and non-invasive. Additionally, the authors discuss the chief studies available in the literature, comparing the results of carotid endarterectomy to percutaneous interventions.

Evolução da terapia endovascular carotídea baseada em um caso / Carotid endovascular therapy evolution based in one case

As técnicas endovasculares para o tratamento da doença obstrutiva carotídea evoluíram substancialmentenos últimos anos. A introdução dos ôstentsõ em vez da simples angioplastia, o início da utilização e o aperfeiçoamento dos dispositivos de proteção cerebral, o incremento do arsenal medicamentoso e a difusão das técnicas e materiais, entre outros, levou a comunidade médica a um imenso interesse na área. O objetivo deste trabalho é demonstrar esta evolução, mostrando o porquê de cada etapa, baseado no nosso primeiro caso de ôstentõ que, sete anos depois, submeteu-se a um novo procedimento na carótida contralateral, permitindo a comparação entre os doisprocedimentos.

The endovascular technique for the treatment of carotid obstructive disease improved substantially in the last years. The addition of stents, the utilization and improvement of cerebral protectiondevices, new drugs and materials, the spread of the techniques and information, among others, bring a great interest in the medical community. Our objective is show this evolution, explaining each step, based on our first stent case which, seven years later, wassubmitted to a new procedure on the other carotid, allowing a beautiful comparison between both procedures.