ULTRASUONI E STENTULTRASUONI E STENT

ALFIO AMATOALFIO AMATOUO di Angiologia e Malattie della Coagulazione UO di Angiologia e Malattie della Coagulazione ““Marino Golinelli”Marino Golinelli”Dpt. Cardio Toraco VascolareDpt. Cardio Toraco VascolarePoliclinico Universitario S.Orsola-Malpighi, BolognaPoliclinico Universitario S.Orsola-Malpighi, BolognaDirettore: Prof. G.PalaretiDirettore: Prof. G.Palareti

VII° Corso Nazionale CongiuntoUltrasonologia Vascolare

Diagnosi e TerapiaEmbolia e Microembolia

Bertinoro 2009

II° Corso Nazionale CongiuntoUltrasonologia VascolareDiagnosi e TerapiaBertinoro 2002

STENT ARTERIOSO DALLA TESTA AI PIEDIALFIO AMATO

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Real Time US Evaluation in Real Time US Evaluation in PTA Stentings PTA Stentings

The concept of vascular stenting The concept of vascular stenting originated with originated with Charles Dotter in Charles Dotter in 19691969, but did not become part of , but did not become part of clinical practice until the late clinical practice until the late 1980s.1980s.

Stent: controllo Stent: controllo angiografico e con IVUSangiografico e con IVUS

Evaluation of Four-Year Coronary Artery Response After Sirolimus-Eluting Stent Implantation Using Serial Quantitative Intravascular Ultrasound and Computer-Assisted Grayscale Value Analysis for Plaque Composition in Event-Free Patients Jiro Aoki, Alexandre C. Abizaid et Al. J Am Coll Card, 2005.

STENT ARTERIOSI E STENT ARTERIOSI E ULTRASUONIULTRASUONI

PTAPTA: la prima metodica di : la prima metodica di controllo della angioplastica e’ controllo della angioplastica e’ stato l’EcoDoppler e stato l’EcoDoppler e successivamente successivamente l’l’EcoColorDopplerEcoColorDoppler,,

PTA-STENTINGPTA-STENTING, non si , non si differenziano per quanto riguarda differenziano per quanto riguarda il tipo di diagnostica, ma nel il tipo di diagnostica, ma nel riconoscere parete arteriosa e riconoscere parete arteriosa e sistema impiantato.sistema impiantato.

Perché gli stent Perché gli stent si vedono?si vedono?

Echogenic Echogenic medical device medical device such as a stent for insertion such as a stent for insertion into a biological tissue or into a biological tissue or vesselvessel comprising an comprising an elongate tube and having at elongate tube and having at least one lumen extending least one lumen extending substantially along a substantially along a longitudinal axis. longitudinal axis.

The elongate tube comprises The elongate tube comprises a a material having an material having an acoustic impedance different acoustic impedance different from the acoustic impedance from the acoustic impedance of the biological tissue or of the biological tissue or vesselvessel of a patient body such of a patient body such that that ultrasonic imaging of ultrasonic imaging of the tube inside the patient’s the tube inside the patient’s body may be achieved. body may be achieved.

The elongate tube may The elongate tube may comprise a comprise a plastic material plastic material such as polyethylene or any such as polyethylene or any formable, pliable materialformable, pliable material..

•

                                        

STENT ARTERIOSI E STENT ARTERIOSI E ULTRASUONIULTRASUONI

La richiesta di La richiesta di controllo ECD di PTAcontrollo ECD di PTA deve considerare deve considerare

1-ESATTA SEDE DEL TRATTAMENTO1-ESATTA SEDE DEL TRATTAMENTO 2-MATERIALE PARIETALE RESIDUO2-MATERIALE PARIETALE RESIDUO 3-STENOSI RESIDUA3-STENOSI RESIDUA 4-STUDIO EMODINAMICO DOPPLER4-STUDIO EMODINAMICO DOPPLER 5-DISSEZIONI SEGMENTARIE5-DISSEZIONI SEGMENTARIE 6-FLAP INTIMALI O FRAMMENTI 6-FLAP INTIMALI O FRAMMENTI

MOBILI MOBILI

STENT ARTERIOSI E STENT ARTERIOSI E ULTRASUONIULTRASUONI

Controllo PTA-STENTINGControllo PTA-STENTING

-LETTURA DELLE MAGLIE -LETTURA DELLE MAGLIE

-SEDE DI IMPIANTO PREVISTO -SEDE DI IMPIANTO PREVISTO

-EVENTUALE MIGRAZIONE-EVENTUALE MIGRAZIONE

-DIMENSIONI: diametro, -DIMENSIONI: diametro, lunghezza.lunghezza.

-STENT IMPRONTATO DALLA -STENT IMPRONTATO DALLA LESIONELESIONE

STENT CAROTIDEO

STENT POST RESTENOSI IN SEGUITO A TEA CAROTIDEA

STENTING CAROTIDEO E TEASTENTING CAROTIDEO E TEA Controllo Non Invasivo dei TrattamentiControllo Non Invasivo dei Trattamenti

CONTROLLI POST TEACONTROLLI POST TEA

Pervietà della CI e CEPervietà della CI e CE

Grado di ristenosi: segmento Grado di ristenosi: segmento trattato, tratto a monte e a valle -trattato, tratto a monte e a valle -morfologia e velocità-morfologia e velocità-

Trombo parietale e sedeTrombo parietale e sede

Gradino della CCGradino della CC

Lembi mobiliLembi mobili

Dissezioni parietaliDissezioni parietali

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POST-TEA

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STENT ARTERIA ILIACA

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Occlusione di stent: dissezione sottointimale e stenosi compressiva

Le procedure endovascolari Le procedure endovascolari sempre piu’ diffuse richiedono sempre piu’ diffuse richiedono abitualmente un importante abitualmente un importante utilizzo di xRay.utilizzo di xRay.

Lo sviluppo attuale dei sistemi Lo sviluppo attuale dei sistemi EchoColor e Power Doppler, basic EchoColor e Power Doppler, basic or with armonics, and also the or with armonics, and also the echo-enhancers bubbles, …echo-enhancers bubbles, …dovrebbe indirizzare ad un dovrebbe indirizzare ad un maggior utilizzo nella PTA-maggior utilizzo nella PTA-stenting dei sistemi US.stenting dei sistemi US.

STENT ARTERIA POPLITEA (?)

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STENTING CAROTIDEO E TEASTENTING CAROTIDEO E TEA Controllo Non Invasivo dei TrattamentiControllo Non Invasivo dei Trattamenti

CONTROLLI POST TEACONTROLLI POST TEA morfologia :morfologia : ecogenicità della lesione ecogenicità della lesione

superficie, estensione, superficie, estensione, diametro minimodiametro minimo

velocità:velocità: criteri adeguati alla nuova criteri adeguati alla nuova

condizione segmentariacondizione segmentaria

STENTING CAROTIDEO STENTING CAROTIDEO Eco Color Doppler Eco Color Doppler

Adesione dello stent alla parete del vasoAdesione dello stent alla parete del vaso Presenza di angolazioni (kinking) della Presenza di angolazioni (kinking) della

carotide interna alla fine dello stent carotide interna alla fine dello stent prodotte dalla diversa compliance fra prodotte dalla diversa compliance fra stent e carotidestent e carotide

Migrazione dello stentMigrazione dello stent Integrità o rotture dello stentIntegrità o rotture dello stent Eventuali complicanze relative ad un Eventuali complicanze relative ad un

precedente intervento di precedente intervento di endoarterectomia (distacco di patch) endoarterectomia (distacco di patch)

Diametro – area residua lungo lo stentDiametro – area residua lungo lo stent PSV – EDVPSV – EDV

VALUTAZIONE ECD STENTVALUTAZIONE ECD STENTI I parametri da valutare sono parametri da valutare sono

diversidiversi da quelli che si da quelli che si considerano dopo intervento considerano dopo intervento

chirurgico chirurgico

• • Pervietà della carotide internaPervietà della carotide interna• • Pervietà della carotide esternaPervietà della carotide esterna• • Presenza di stenosi nel segmento trattatoPresenza di stenosi nel segmento trattato• • Presenza di stenosi (nuovo ateroma, Presenza di stenosi (nuovo ateroma,

iperplasia, trombo) all’interno dello stent iperplasia, trombo) all’interno dello stent (in-stent restenosis)(in-stent restenosis)• • Presenza di stenosi a monte o a valle Presenza di stenosi a monte o a valle

dello stentdello stent• • Presenza di trombo parietalePresenza di trombo parietale

CONTROLLI ECO COLOR DOPPLER CONTROLLI ECO COLOR DOPPLER POST TEA POST TEA

Color Doppler a 1- 4 - 8 - 12 - 18 mesi.Color Doppler a 1- 4 - 8 - 12 - 18 mesi. poi a 2 - 4 - 6 - 8 anni.poi a 2 - 4 - 6 - 8 anni. Se la carotide controlaterale è Se la carotide controlaterale è

stenotica eseguire i controlli secondo il stenotica eseguire i controlli secondo il follow-up per le stenosi note.follow-up per le stenosi note.

ANALOGHI CONTROLLI POST STENT (?)ANALOGHI CONTROLLI POST STENT (?)

E dopo molti anni (?)E dopo molti anni (?)

ICAROS STUDYICAROS STUDYImaging in Carotid Angioplasties and Imaging in Carotid Angioplasties and

Risk Of StrokeRisk Of Stroke

Registro internazionale Registro internazionale multicentrico stenting carotideo multicentrico stenting carotideo

Indentificazione pazienti ad alto e basso Indentificazione pazienti ad alto e basso rischio di stroke ad 1 annorischio di stroke ad 1 anno

Biasi GM, Nicolaides AN et Al, J Endovasc Ther, 2001Biasi GM, Nicolaides AN et Al, J Endovasc Ther, 2001

Biasi GM, Diethrich EB, Nicolaides AN, Circulation, 2004 Biasi GM, Diethrich EB, Nicolaides AN, Circulation, 2004

IVUS IN CAROTID STENTINGIVUS IN CAROTID STENTING

CONTROLLI SERIATI CONTROLLI SERIATI ENDOVASCOLARIENDOVASCOLARI

POST PROCEDURA E DOPO 6 MESIPOST PROCEDURA E DOPO 6 MESI Diametro minimo del lume Diametro minimo del lume Misurazione dell’area di Misurazione dell’area di

impiantoimpianto Area dello stentArea dello stent Area dell’iperplasia neointimaleArea dell’iperplasia neointimale Clark DJ et Al, J Am Coll Clark DJ et Al, J Am Coll

Cardiol, 2006Cardiol, 2006

IVUS IN CAROTID STENTINGIVUS IN CAROTID STENTING

I “self-expanding stents” I “self-expanding stents” determinano una notevole determinano una notevole iperplasia della neointima iperplasia della neointima

Processo bilanciato dal tardivo Processo bilanciato dal tardivo incremento del diametro dello stentincremento del diametro dello stent

Dimensioni ridotte dello stent subito Dimensioni ridotte dello stent subito dopo la procedura sono associate dopo la procedura sono associate con alto rischio di “in-stent con alto rischio di “in-stent restenosis”restenosis”

Clark DJ et Al, J Am Coll Cardiol, 2006Clark DJ et Al, J Am Coll Cardiol, 2006

nuovi criteri velocimetricinuovi criteri velocimetrici

Lo stent riduce la compliance Lo stent riduce la compliance dell’arteria e pertanto i dell’arteria e pertanto i criteri velocimetrici criteri velocimetrici normalmente utilizzati per la normalmente utilizzati per la valutazione della stenosi valutazione della stenosi possono non essere possono non essere applicabili. applicabili.

Gli studi in Letteratura in Gli studi in Letteratura in proposito sono in proposito sono in incremento. incremento.

nuovi criteri nuovi criteri velocimetricivelocimetrici

Lal BK et Al. propongono i seguenti Lal BK et Al. propongono i seguenti valori per identificare una valori per identificare una carotide carotide normale dopo stenting (stenosi < normale dopo stenting (stenosi < 20%):20%):

• • PSV < 150 cm/s,PSV < 150 cm/s, • • ICA/CCA ratio < 2.16ICA/CCA ratio < 2.16 J Vasc Surg. 2004 Jan;39(1):58-66J Vasc Surg. 2004 Jan;39(1):58-66 Dovranno essere definiti nuovi Dovranno essere definiti nuovi

criteri velocimetrici per le criteri velocimetrici per le varie classi di stenosivarie classi di stenosi

Real Time US Evaluation in PTA Real Time US Evaluation in PTA StentingsStentings

In 1988 our group in Bologna, together with In 1988 our group in Bologna, together with angioradiologists, performed an Echo Doppler angioradiologists, performed an Echo Doppler PTA procedure of Common Iliac Artery PTA procedure of Common Iliac Artery stenosis.stenosis.

It was the first Echo-Duplex guided PTA It was the first Echo-Duplex guided PTA treatment in Italy. treatment in Italy.

We presented the procedure on video-tape We presented the procedure on video-tape during a session of the Italian Society of during a session of the Italian Society of Vascular Pathology.Vascular Pathology.

Real Time US Evaluation in PTA Real Time US Evaluation in PTA StentingsStentings

A young male smoker (aged 42 A young male smoker (aged 42 years), with a segmentary years), with a segmentary atheromasic lesion of the atheromasic lesion of the common iliac artery discovered common iliac artery discovered by Duplex Scanner evaluation for by Duplex Scanner evaluation for PAD symptoms,underwent a PAD symptoms,underwent a simple PTA of the vessel.simple PTA of the vessel.

Stents were not yet used in Stents were not yet used in clinical practical.clinical practical.

PTA-STENTINGPTA-STENTING

Possibilità di effettuare la Possibilità di effettuare la procedura con guida Eco Color procedura con guida Eco Color

Doppler (?) per: Doppler (?) per: Valutare gli effetti sulla parete Valutare gli effetti sulla parete

vasalevasale Effettuare brevi campionamenti Effettuare brevi campionamenti

DopplerDoppler Ridurre la durata della manovra Ridurre la durata della manovra

????

Real Time US Evaluation in PTA Real Time US Evaluation in PTA StentingsStentings

STENTS CANNOT PREVENT RESTENOSISSTENTS CANNOT PREVENT RESTENOSIS

1. 1. RestenosisRestenosis is believed tois believed to start the instant of start the instant of balloon angioplastyballoon angioplasty –stent placement secondary –stent placement secondary to the vascular injury that occurs when a narrowed to the vascular injury that occurs when a narrowed artery is forcibly expandedartery is forcibly expanded..

2. Trauma to the vessel2. Trauma to the vessel in the form of shearing of in the form of shearing of the intima and fissuring on the wall of the vessel the intima and fissuring on the wall of the vessel maymay induce excessive deposition of fibrin, induce excessive deposition of fibrin, platelets and leukocytes.platelets and leukocytes.

SchatzSchatz, Circulation,1989; , Circulation,1989; Palmaz,Palmaz, AJR, 1993; AJR, 1993; Serruys,Serruys, Heparin pilot study, Circul.1996Heparin pilot study, Circul.1996

TREATMENT OF CAROTID STENOSIS: TREATMENT OF CAROTID STENOSIS: CAROTID SURGERY OR STENT?CAROTID SURGERY OR STENT?

ROLE OF DUPLEX ULTRASOUND ROLE OF DUPLEX ULTRASOUND (US):(US):

Degree of stenosisDegree of stenosis Plaque morphology - soft vs hardPlaque morphology - soft vs hard

-trhombotic or ulcerous formations-trhombotic or ulcerous formations

• • Detection of HITS by transcranial Detection of HITS by transcranial DopplerDoppler

CAROTID STENTS: CAROTID STENTS: Duplex US follow-up of arterial Duplex US follow-up of arterial

remodellingremodelling

Diameter increase (over 2 years)Diameter increase (over 2 years) Neo-intimal thickness increase (up Neo-intimal thickness increase (up

to 12 months)to 12 months) Flow-ratio increase (douring first Flow-ratio increase (douring first

year)year) Compliance reductionCompliance reduction Intravascular us scanning of beta Intravascular us scanning of beta

emitting ((55)Co) stentsemitting ((55)Co) stents

Factors not reducing restenosis

•Type of metal

•Surface area of the stent

•Degree of hoop strength of the stent

•Heparin coating

•Long term Warfarin

•Anti-platelet therapy (?)

US Evaluation in PTA Stentings

Plaques with:• low echogenicity • stenosis ≥90%

produced a higher number of embolic particles after ex vivo balloon angioplasty and stenting. Therefore these lesions may be less suitable for balloon angioplasty and stenting with currently used devices. Ex vivo human carotid artery bifurcation stenting: Correlation of lesion characteristics with embolic potential.Takao Ohki, Michael L. Marin, Ross T. Lyon, George L. Berdejo, Krish Soundararajan, Mika Ohki, Peter L. Faries, Reese A. Wain, Luis A. Sanchez,

William D. Suggs, Frank J. Veith. J Vasc Surg 1998; 27:463-71

STENT MARKET ?STENT MARKET ?

17% ANNUAL GROWTH FORECAST IN PERIPHERAL 17% ANNUAL GROWTH FORECAST IN PERIPHERAL VASCULAR STENT MARKET.VASCULAR STENT MARKET.------------------------------------------------------------------------------------------------------------------------

MR-velocity mapping in vascular stents to assess MR-velocity mapping in vascular stents to assess peak systolic velocity. In vitro comparison of peak systolic velocity. In vitro comparison of various stent designs made of Stainless Steel and various stent designs made of Stainless Steel and Nitinol. Nitinol. Jacqueline van Holten, Patrik Kunz, Jacqueline van Holten, Patrik Kunz, Paul G. H. Mulder,Peter M.T. Pattynama, Hildo J. Lamb, Paul G. H. Mulder,Peter M.T. Pattynama, Hildo J. Lamb,

Magnetic Resonance Materials in Physics, Biology and Medicine 15 (2002) 52-57

The missing stentThe missing stent

Missed Double-J stent by Missed Double-J stent by ultrasonography. ultrasonography.

G. Pandurangan, B.BastaniG. Pandurangan, B.Bastani. . Nephrol Dial Transplant Nephrol Dial Transplant (2000) 15: 1099-1100(2000) 15: 1099-1100

The Missing Stent - The Most Improbable The Missing Stent - The Most Improbable ComplicationComplicationB. Schmidta, A. Gramseb, A. Heringb, U. Liebersa, S. B. Schmidta, A. Gramseb, A. Heringb, U. Liebersa, S. Hörniga, M. Johna, C. Witta. Hörniga, M. Johna, C. Witta. RespirationRespiration 2005;72:304 2005;72:304

Healing of Carotid Stents: A Prospective Healing of Carotid Stents: A Prospective Duplex Ultrasound StudyDuplex Ultrasound Study

Andrea Willfort-Ehringer; RamazanaliAndrea Willfort-Ehringer; Ramazanali Ahmadi; Michael E. Ahmadi; Michael E. Gschwandtner; Angelika Haumer; Gottfried Heinz; Wilfried Lang; Gschwandtner; Angelika Haumer; Gottfried Heinz; Wilfried Lang;

Herbert EhringerHerbert Ehringer

Journal of Endovascular Therapy:Journal of Endovascular Therapy: Vol. 10, No. 3, 2005 Vol. 10, No. 3, 2005

Day after the stent procedure and at 1, 3, 6, 12, and 24 months Day after the stent procedure and at 1, 3, 6, 12, and 24 months in follow-up:in follow-up:

The maximal thickness and echogenicity of the layer between the The maximal thickness and echogenicity of the layer between the stent and the perfused lumen (SPL) were evaluated. stent and the perfused lumen (SPL) were evaluated.

Echogenicity was classified as echogenic if the SPL layer Echogenicity was classified as echogenic if the SPL layer was clearly detected in B mode and echolucent if the SPL was clearly detected in B mode and echolucent if the SPL layer was barely visible in B mode, its border defined by layer was barely visible in B mode, its border defined by assistance of color-coded flow. assistance of color-coded flow.

1) an early unstable period soon after stent placement 1) an early unstable period soon after stent placement with an echolucent (thrombotic) SPL layer,with an echolucent (thrombotic) SPL layer,

(2) a moderately unstable phase with ingrowing (2) a moderately unstable phase with ingrowing neointima (1–12 months),neointima (1–12 months),

(3) a stable phase from the second year on. These data (3) a stable phase from the second year on. These data may indicate the need for different intensities of therapy may indicate the need for different intensities of therapy and surveillance intervals. and surveillance intervals.

Risk of Stroke in Carotid Risk of Stroke in Carotid Stenting (?)Stenting (?)

Plaque Echolucency Is Not Associated With Plaque Echolucency Is Not Associated With the Risk of Stroke in Carotid Stentingthe Risk of Stroke in Carotid Stenting

Markus Reiter; Robert A. Bucek; Isabella Effenberger; Johanna Markus Reiter; Robert A. Bucek; Isabella Effenberger; Johanna Boltuch; Wilfried Lang; Ramazanali Ahmadi; Erich Minar; Martin Boltuch; Wilfried Lang; Ramazanali Ahmadi; Erich Minar; Martin Schillinger. Schillinger.

Stroke. 2006;37:2378-2380Stroke. 2006;37:2378-2380

??

Survival Following Renal Artery Stent Survival Following Renal Artery Stent Revascularization.Revascularization.

Four-year Follow-up. Four-year Follow-up.

Mayra Guerrero, Asmir Syed, Sandeep Mayra Guerrero, Asmir Syed, Sandeep KhoslaKhosla.. J Invasive Cardiology, 2004J Invasive Cardiology, 2004

In our database, patients undergoing renal artery In our database, patients undergoing renal artery stent revascularization for suspected renovascular stent revascularization for suspected renovascular hypertension had an overall survival of 83% at 4 hypertension had an overall survival of 83% at 4 years post procedure. Patients with higher baseline years post procedure. Patients with higher baseline serum creatinine, male gender, bilateral renal serum creatinine, male gender, bilateral renal artery stenosis and systolic dysfunction, had artery stenosis and systolic dysfunction, had statistically significant lower survival at 4 years. statistically significant lower survival at 4 years.

The future

It is hoped that the next generation of stents will combine the mechanical advantages of stents with pharmacologic advantages and coverings which will prove to have a substantial impact on the restenosis issue.