How Post Thrombotic Syndrome Develops
DVT Diagnosis• What is the pertinent data?– Duplex scanning is current standarddiagnostic tool– Overall, positive (97%) & negative (98%) value• Kearon C, Julian JA, Math M, etal.Ann Intern Med. 128: 663-677, 6 1998.
DVT Diagnosis ProtocolSuspect Acute DVTWells criteriaLow Moderate High D-dimer(-)ExcludesDVTD-dimer(+)(-)D-dimer(+)ConsiderLMWHoff hoursDuplex
Current Standard Therapy forDVT: Anticoagulationi• Initial therapy of LMW heparin orunfractionated heparin• Long term oral warfarin - three to six months• Anticoagulation is effective at prevention offatal pulmonary embolism and has anacceptable bleeding complication rate– However, this strategy relies on the patient’sfibrinolytic system for thrombolysis• Veins have limited capacity to dissolve thrombus 22. Comerota et al; “Iliofemoral Venous Thrombosis”; J Vasc Surg 2007; 46:1065-1076
DVT TreatmentEvolution Timeline1950 Anticoagulation Therapy95% of Today’s Treatment1980 Systemic Thrombolysis1990 Catheter Directed Thrombolysis2000 Pharmacomechanical ThrombolysisIsolated TdToday PharmacomechanicalThrombolysis
Deep Vein ThrombosisPharmaceutical (Oral and IV)What: LMWH Heparin or UnfractionatedHeparin, then Warfarin (Coumadin)Why: Reduces clotting, prevents clotpropagation and reduces incidence of PEDuration: Dependent upon etiology (3-6months or lifelong)Treatment TherapiesCatheter DirectedThrombolysis (CDT)What: Infusion of thrombolytic agentsdirectly into thrombosed vessel with theuse of an infusion catheterWhy: Direct localization of agent tothrombusDuration: 8-72 hoursMechanical ThrombectomyWhat: Treatment that uses an endovascular orsurgical approach to fragment and evacuate clot.Embolectomy catheter, Aspiration guide catheters,,Mechanical devicesWhy: Used when patient is contraindicated foranticoagulation or thrombolytic therapiesDuration: 1t to 3+ hoursPharmacomechanicalThrombolysis Treatments (PMT)What: Infuses and disperses thrombolyticagents to dissolve, remove thrombus andrestore vessel patencyWhy: Uses mechanical energy to dispersethrombolytic directly at the thrombus locationDuration: 1-3 hours1. Hilleman, Razavi; “Clinical and Economic Evaluation of the Trellis-8 Infusion Catheter for Deep Vein Thrombosis”; J Vasc Interv Radiol 2008; 19:377-383
Benefits of PharmacomechanicalThrombolysis with IsolationIsolated PharmacomechanicalThrombolysis• Thrombus isolated betweenoccluding balloons• Lytic isolated between occludingballoons• Reduction in thrombolytic dosing 1• Aspiration of thrombus and lytic• 84% single setting thrombusremoval 2• Reduces/eliminates ICU time1. O’ Sullivan et al; “Pharmacomechanical Thrombectomy of Acute Deep Vein Thrombosis with the Trellis‐8 Isolated Thrombolysis Catheter”; JVasc Interv Radiol; 18:715‐7242. September 2010 Covidien Trellis Commercial Registry Report
Isolated PharmacomechanicalThrombolysis ProcedureThrombolysis ProcedureTrellis Systemdelivered overguidewireIsolatedthrombus &targeted deliveryof thrombolyticSingleInterventionalProcedure in84% of cases*
Choosing the Right TreatmentLytic Exposure Time 1Lytic ExposureMethodCatheterDirected Directed -Thrombolysis Systemic(CDT)Trellis System Concentrated -IsolatedInfusion TimeProcedure Time25.22 h + 12.22 44h+ 4.4h 25 2.522 min + 11 2.0h + 1.01. Hilleman, Razavi; “Clinical and Economic Evaluation of the Trellis-8 Infusion Catheter for Deep Vein Thrombosis”; J Vasc IntervRadiol 2008; 19:377-383
Isolated PMT Clinical Data2,100 + Patient Clinical RegistryResultsl ThrombolysisMajor Bleed RatesIsolatedPharmacomechanicPharmacomechanica Ultrasound Assistedal ThrombectomyCDT(EndoWave*) 42(Trellis System) 1 (AngioJet*) 30.05% 3.8% 5.3% 11%1. February 2010 Covidien Trellis Commercial Registry Report2. S. Parikh et al, “Ultrasound-accelerated Thrombolysis for the Treatment of Deep Vein Thrombosis: Initial Clinical Experience “;J Vasc IntervRadiol ,2007;19, 4, :521-5283. Kim et al. “Adjunctive Percutaneous Mechanical Thrombectomy for Lower-extremity Deep Vein Thrombosis: Clinical and Economic Outcomes”. J Vasc Interv Radiol 2006; 17:1099-11044. Mewissen et al. “Catheter-directed Thrombolysis for Lower Extremity Deep Venous Thrombosis: Report of a National Multicenter Registry”.Radiology 1999; 211:39-49
Isolated PMT Clinical Data2,100 + Patient Clinical Registry*ClinicalData• 84% SingleInterventionalProcedure• 95% Grade II & IIILysis Achieved AllChronicities• 76% AdjunctiveProcedures (PTA,Stenting, etc.)• Largest CommercialVenous Registry* Source: Covidien Trellis Commercial Registry , September 2010
Trellis System Treatment PathwayImprovedPatient QOLUltrasoundConfirmation ofDVTDecreased longterm PTSmorbidity andcosts 22 hour SingleInterventionalti Procedure 11. Source: Covidien Trellis CommercialRegistry , September20102. 1. Comerota et al. “IliofemoralVenous Thrombosis”; J Vasc Surg2007; 46:1065‐1076Begin AnticoagulationContinueAnti-CoagulationTherapyTRELLISSYSTEMSymptomReliefRestore VesselPatency
Isolated Thrombolysis of IliacVein(6 mg rt-PA for 15 minutes)
Post Procedure Nursing Care• Monitor for post procedure hematoma• Leg Elevation• Sequential calf compression• Start Lovenox or heparin postprocedure• Start wararin• Patient can be discharged onanticoagulation and compressionstockings
Case History30 female presents with painfulswelling of the right leg. Duplexshowed right leg DVT. CT venogramconfirmed extension into the iliacsystem and inferior vena cava. Pt. wason oral contaceptives and had no priorhistory of DVT
Case History27 male presented with 2 weeks historyof painful swelling of left leg. He wasdiagnosed with left leg DVT andextension of clot in iliac vein with CTevidence of May Thurner Syndrome
Angiojet Thrombectomy• High pressure saline infusion andaspiration of thrombus Venturi Effect• TPA infused as power pulse spray• Useful as thrombectomy catheterwithout t TPA• Prolonged use can cause hemolysisand hemoglobinuria
Angiojet Catheter Thrombectomy
A Faster, Safer TreatmentAlternative For TheDissolution of ThrombusMicroSonicAcceleratedThrombolysis
A Superior Way To Dissolve Clots• Minimally invasive procedure, performed in thecath lab or interventional suite• Uses a sophisticated endovascular device tosimultaneously deliver microsonic energy andthrombolytics at the site of the clot• Liquifies thrombus without maceration orfragmentation• Clears more clots, more completely• Significantly reduces treatment time and lyticdosage
Why Thrombus Is So Difficult To Dissolve• Speed of lysis depends on ability of lytic to access plasminogen receptor sites**• Plasminogen receptor sites are embedded into thrombus during formation• Tightly wound fibrin strands prevent lytic from penetrating the thrombus, limitingaccess plasminogen receptor sites** Francis, Charles W. et al. “Ultrasound Accelerates Transport of Recombinant Tissue PlasminogenActivator into Clots.” Ultrasound in Medicine and Biology 21.3 (1995): 419-424.
How Microsonic Energy Unlocks TheClot…Mechanism ofAction• Microsonic energy causesfibrin strands to thin andloosen, exposingplasminogen receptor sites,• Thrombus permeability andlytic penetration aredramatically increased• Microsonic pressure wavesforce lytic agent deep intothe clot and keep it thereWITHOUT MICROSONICENERGYMICROSONIC ENERGY& THROMBOLYTIC…With • No Thrombolysis Evidence of Fibrin resultsStrand Breakage 44Braaten, J., Goss, R., and Francis, CW. “Ultrasound Reversibly Disaggregates Fibrin Fibers.”Thromb Haemost 78 (1997) 1063-8.WITH MICROSONICENERGY
Complementary ActionFibrin SeparationNon Cavitational UltrasoundSeparates Fibrin withoutFragmentation EmboliFor better Receptor Site AvailabilityActive Drug DeliveryLytic Agent is continuously driven into clot by“Acoustic Streaming”WithoutUltrasoundWithUltrasoundAcoustic Streaming53
Microsonic…mechanism of actionStandard Infusion Catheter Plasma ClotEkoSonic EndovascularDevicePlasma ClotSpread ofStained t-PASpread of Stained t-PAThrombus exposed to ultrasound absorbed 48% more t-PA inone hour, 84% more t-PA in two hours and 89% more t-PA in4 hours than thrombus not exposed to microsonic pressure. 33Francis, CW, et al. “Ultrasound Accelerates Transport of Recombinant Tissue Plasminogen Activator into Clots.”Ultrasound in Medicine and Biology 21.3 (1995): 419-424.
MicroSonic Accelerated Thrombolysis5675Parikh, S., Motarjeme, A., et. al. “Ultrasound-Accelerated Thrombolysis for the Treatment of Deep Vein Thrombosis: InitialClinical Experience”. Journal of Vascular and Interventional Radiology, Volume 19, Issue 4, April 2008, pp 521-528.6Levine, MN et al. Hemorrhagic Complications of Anticoagulant Treatment: The 7 th ACCP Conference on Antithrombotic andThrombolytic Therapy. Chest 2004; 126:287-3107Mewissen, et al. National Venous Registry. Radiology, 1999. Results are post-adjunctive therapy.
Benefits of MicrosonicAccelerated Thrombolysis• Very low incidence of bleeding– One study showed 2 puncture sitehematomas out of 91 cases– Bleeding rate is the same as bleeding rate inWarfarin• Fast and easy to place the device via catheter• Less lab time• Patient is out of bed faster• 86% totally clear in 18.5 hours
Benefits of Microsonic acceleratedThrombolysis• Dissolves clots more completely to restoreblood flow and valve function• Successfully penetrates clots in difficult toreach places, such as behind valves• Significantly shortens infusion duration• Uses lower lytic drug dosage, so there is lesslikelihood of hemorrhagic complications• Reduced risk of infection, because of shortercatheter dwelling time
Advantages Over MechanicalDevices• Lytic penetrates behind venous valves withoutdamaging them• Does not fracture or break the thrombus, thusreducing the risk of emboli• Does not fracture red blood cells…no adenosinerelease, no additional strain on kidneys• Saves lab and physician time ….Place the catheterand be out of the lab in 20 minutes• Lower drug dosage …. Reduce the risk of bleeding
Treatment Exclusion Criteria• Blood clotting disorders• Clot older than 30 days• Pregnancy• History of Internal Bleeding• Advanced age• Recent surgery or injury• Poorly controlled hypertension• Sensitivity to contrast t agent• Diabetic retinopathy10Canadian Family Physician, February 2005, Editorial, Management of venous thromboembolism.www.cfpa.ca
Endovascular Management of PulmonaryEmbolism• Microsonic catheters can be used to lyse pulmonaryartery clots• Trials are currently being conducted in USA• Approved in Europe• Holds a promise in patients t with pulmonaryhypertension
Therapeutic Goals of DVTTreatment• Relieve patient symptoms• Prevent PE• Prevent further thrombus propagation• Prevent DVT recurrence• Maintain valve competence• Prevent Post Thrombotic Syndrome(PTS)
Post procedure Nursing Care• Ensure that all lines are connected tocorrect pumps and catheters• Monitor for post procedure hematomas• CBC and fibrinogen monitoring every 6hours• Monitor patient for shortness of breathand chest pain• Leg elevation sequential calfcompression
Anticoagulation Alone……does prevent clot propagation.…does reduce risk of pulmonary embolism.…does not resolve clot.…does not prevent valvular damage.…does not prevent venous hypertension.…does not prevent Post-ThromboticSyndrome.…does not rapidly resolve symptoms.…is not enough.
The Paradigm Has Shifted• Anticoagulation alone is not enough 2• Thrombolysis is now recognized by national guidingorganizations for the first time as a validinterventional approach to treating DVT• NQF/Joint Commission requires that hospitals havean evidence-based thrombolysis protocol 8• New Guidelines must be considered d when modifyingiDVT treatment protocols8. National Quality Forum.”National Voluntary Consensus Standards for Prevention and Care of VenousThromboembolism: Policy, Preferred Practices, and Initial Performance Measures.” 20089. Kearon et al. “Antithrombotic Therapy for Venous Thromboembolic Disease: American College ofChest Physicians Evidence-Based Clinical Practice Guidelines”. Chest 2008; 133:454-545
NQF/Joint CommissionMay 15, 2008Seven measures identified d focusing on VTEpatient management:• Hospital care and preparation to manageand/or avoid VTE• Extend focus beyond the hospital bytargeting patient readiness and educationat discharge
Written Policy• NQF requires the use of evidence-basedpractices• Society for Vascular Surgery evidencebasedguidelines suggest the use ofthrombolytic therapy in patients withextensive acute proximal DVTU f th b l ti th t b d fi d• Use of thrombolytic therapy to be definedas part of the hospital’s DVT protocol
The Evidence is InNQF/JC: Guidance for VTE ManagementSurgeon General call to actionCreate or Modify Our DVT Protocol
We Are A People On The Move...Modern Treatment Methods Must AccommodateOur Life Style
It Also Makes ConservativeMedical Management MuchLess Acceptable
Treatment Flow• Patient is diagnosed with iliofemoral orsubclavian DVT• Begin anticoagulation regimen• Consult to DVT interventionalist• Perform parmacomechanical thrombectomywhen indicated or catheter basedthrombolysis• Step-down room (81% Single Setting)• Release on anticoagulation therapy andcompression stockings
Follow up• Treat anatomic lesion at the time ofintervention• Anticoagulate for 3-6 months• At the end of therapyhypercoagulability work up• Decide about long term anticoagulation
Conclusions• Pharmacomechanical thrombolysisand catheter based thrombolysis issafe and effective treatment forDVT• It should be considered as the firstline treatment of DVT in selectgroup of patients
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