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Peripheral AVM: endovascular Peripheral AVM: endovascular management management Dr. Hazem Habboub Dr. Hazem Habboub King Hussein Medical Center King Hussein Medical Center Amman - Jordan Amman - Jordan

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  1. 1. Peripheral AVM: endovascularPeripheral AVM: endovascular managementmanagement Dr. Hazem HabboubDr. Hazem Habboub King Hussein Medical CenterKing Hussein Medical Center Amman - JordanAmman - Jordan
  2. 2. INTRODUCTIONINTRODUCTION Vascular malformationsVascular malformations are among the most commonare among the most common congenital abnormalities observed in infants and children.congenital abnormalities observed in infants and children. Unfortunately, these lesions are also among the mostUnfortunately, these lesions are also among the most confusing and misunderstood conditions, largely becauseconfusing and misunderstood conditions, largely because of a history of inconsistent terminology used forof a history of inconsistent terminology used for classification.classification. Vascular malformationsVascular malformations are considered a group ofare considered a group of conditions typied by localized defects in vascularconditions typied by localized defects in vascular morphogenesis caused by dysfunction in embryogenesismorphogenesis caused by dysfunction in embryogenesis and vasculogenesisand vasculogenesis
  3. 3. Vascular MalformationsVascular Malformations Diffuse disorder of vascular anomalies.Diffuse disorder of vascular anomalies. 1982 : Mulliken and Glowacki: 2 groups1982 : Mulliken and Glowacki: 2 groups HaemangiomasHaemangiomas Vascular MalformationsVascular Malformations 1992: International society for the study of vascular1992: International society for the study of vascular anomalies-ISSVA- sentinel classificationanomalies-ISSVA- sentinel classification --Vascular tumorsVascular tumors -vascular malformations: Divided by Dynamic flow-vascular malformations: Divided by Dynamic flow characteristic: High flow and Low flow.characteristic: High flow and Low flow.
  4. 4. Agenda:Agenda: DifferentiationDifferentiation DiagnosisDiagnosis TreatmentTreatment Arteriovenous malformations
  5. 5. -Vascular malformations are often referred to as-Vascular malformations are often referred to as iceberg lesionsiceberg lesions --Clinical history andClinical history and examinationexamination can usually differentiate highcan usually differentiate high and low ow lesions with imaging being used to: 1.conrm theand low ow lesions with imaging being used to: 1.conrm the diagnosis, 2. evaluate morphology and 3. to plan treatment.diagnosis, 2. evaluate morphology and 3. to plan treatment. --Treatment is generally reserved for those patients with signicant symptomatic lesions or cosmetic defects
  6. 6. PATHOPHYSIOLOGYPATHOPHYSIOLOGY Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations Arteriovenous malformationsArteriovenous malformations are considered to be congenitalare considered to be congenital vascular anomalies, but are usually first noted several years aftervascular anomalies, but are usually first noted several years after birth or after certain triggering changes such as trauma or thebirth or after certain triggering changes such as trauma or the hormonal changes of puberty or pregnancy.hormonal changes of puberty or pregnancy. Arteriovenous fistulas (AVFs)Arteriovenous fistulas (AVFs) are simple arteriovenous connections.are simple arteriovenous connections. Most AVFs are secondary to penetrating injuries after birth,Most AVFs are secondary to penetrating injuries after birth, although some are believed to be congenital.although some are believed to be congenital.
  7. 7. PATHOPHYSIOLOGYPATHOPHYSIOLOGY Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations An AVM is an abnormal connection or connections between anAn AVM is an abnormal connection or connections between an artery and vein .In this situation blood bypasses the capillary networkartery and vein .In this situation blood bypasses the capillary network within organs and tissues and the normal pressure down regulation doeswithin organs and tissues and the normal pressure down regulation does not occur. The rst dilated segment of vein after this connection isnot occur. The rst dilated segment of vein after this connection is termed thetermed the nidus.nidus.
  8. 8. Histological Analysis of AVMsHistological Analysis of AVMs Histological analysis of AVMs has shed some light onHistological analysis of AVMs has shed some light on their pathogenesistheir pathogenesis Examination of specimens revealed that a nidus is madeExamination of specimens revealed that a nidus is made up of a bed of dilated capillaries.up of a bed of dilated capillaries. As the lesion matures, the degree of ectasia increases, andAs the lesion matures, the degree of ectasia increases, and the development of venous dilation and arterialthe development of venous dilation and arterial hypertrophy becomes apparent.hypertrophy becomes apparent. The primary abnormality or nidus, therefore, appears toThe primary abnormality or nidus, therefore, appears to be anbe an ectatic capillary bed.ectatic capillary bed. Arterial hypertrophy and venous dilation are secondaryArterial hypertrophy and venous dilation are secondary phenomena that result from the increase flow across thephenomena that result from the increase flow across the nidus.nidus.
  9. 9. Histological Analysis of AVMsHistological Analysis of AVMs (continued(continued(( Because the nidus is simply an ectatic capillary bed and because theBecause the nidus is simply an ectatic capillary bed and because the precapillary sphincters regulate the blood flow through theprecapillary sphincters regulate the blood flow through the capillary bed, we believe that arteriovenous malformations resultcapillary bed, we believe that arteriovenous malformations result from an abnormality at the level of thefrom an abnormality at the level of the precapillary sphincterprecapillary sphincter.. An absence of autonomic nerve supply to the sphincters, anAn absence of autonomic nerve supply to the sphincters, an absence of the actual sphincters, or some deficiency in theabsence of the actual sphincters, or some deficiency in the neuroreceptors at this level will result in free flow across thatneuroreceptors at this level will result in free flow across that particular capillary bed.particular capillary bed. In time, the vessels in the bed dilate, and eventually the areaIn time, the vessels in the bed dilate, and eventually the area supplying the arteries enlarge and the veins dilate.supplying the arteries enlarge and the veins dilate. This absence of capillary sphincter control may be absolute orThis absence of capillary sphincter control may be absolute or relative, hence the variation in age of presentation and speed ofrelative, hence the variation in age of presentation and speed of progression.progression.
  10. 10. AVMs Growth and BleedingAVMs Growth and Bleeding CycleCycle?? Some people are born with the nidus. As years go by, it tends toSome people are born with the nidus. As years go by, it tends to enlarge as the pressure of the arterial vessels cannot be handled byenlarge as the pressure of the arterial vessels cannot be handled by the veins that drain out of it.the veins that drain out of it. Most of these malformations bleed between the ages of 10-55;Most of these malformations bleed between the ages of 10-55; after 55, the chances of bleeding diminishes rapidly. Before 55,after 55, the chances of bleeding diminishes rapidly. Before 55, the likelihood of hemorrhaging is between 3-4% per year (with athe likelihood of hemorrhaging is between 3-4% per year (with a death incidence of about 1%).death incidence of about 1%). Once a patient has hemorrhaged, the risk of having another oneOnce a patient has hemorrhaged, the risk of having another one may approach 20% during the first year, and will gradually lessenmay approach 20% during the first year, and will gradually lessen to about 3-4% over the next few years.to about 3-4% over the next few years.
  11. 11. What Are Some AVM StatisticsWhat Are Some AVM Statistics AMVs affect approximately 300,000 Americans.AMVs affect approximately 300,000 Americans. In the Netherlands between 1980 and 1990, the annual incidenceIn the Netherlands between 1980 and 1990, the annual incidence of symptomatic AVMs was 1.1 per 100,000 population.of symptomatic AVMs was 1.1 per 100,000 population. They occur equally in males and females from all ethnic and racialThey occur equally in males and females from all ethnic and racial backgrounds.backgrounds. They are more prevalent in late childhood (over 9 years of age)They are more prevalent in late childhood (over 9 years of age) than early childhood, although they can occur at any age.than early childhood, although they can occur at any age. More than 50% present with intracranial AVMs.More than 50% present with intracranial AVMs. About 12% of the affected population will present with symptomsAbout 12% of the affected population will present with symptoms that vary greatly in severity.that vary greatly in severity. Each year about 1% of those with AVMs will die as a direct resultEach year about 1% of those with AVMs will die as a direct result of the AVM.of the AVM.
  12. 12. PATHOPHYSIOLOGYPATHOPHYSIOLOGY Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations Classification: Hudart Classification -Type 3 is the commonest(>60%). And most difficult to treat. Type 1 Arteriovenous No more than 3 separate arteries Type 2 Arteriolovenous Multiple arteries shunt to a single vein Type 3 Arteriolovenulous Multiple shunts between arteries and venules. Multiple nidi
  13. 13. Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations Clinical features: Depends on the region of involvement & degree of shunting Pain Overgrowth Bleeding High cardiac output: less common, large AV shunt Rapid growth over short time, Swelling ,especially after trauma. Schobinger Schobinger classification Type 1 Queiscent-stable Type2 Growing Type3 Symptomatic:Pain ,bleeding,functional problems Type4 Decompensating,high flow cardiac output
  14. 14. SIGNS AND SYMPTOMSSIGNS AND SYMPTOMS Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations Arteriovenous malformations (AVMs) are generally present in neonates atArteriovenous malformations (AVMs) are generally present in neonates at birth, but they often suddenly become obvious when the patient is olderbirth, but they often suddenly become obvious when the patient is older because of various stimuli such as trauma, pregnancy, or puberty. There arebecause of various stimuli such as trauma, pregnancy, or puberty. There are four recognized stages of AVMs:four recognized stages of AVMs: Stage IStage I lesion has a pinkish-bluish stain and warmth.lesion has a pinkish-bluish stain and warmth. Stage IIStage II, the lesion has pulsations, thrill, and bruit., the lesion has pulsations, thrill, and bruit. Stage IIIStage III, the patient has dystrophic skin changes, ulceration, bleeding,, the patient has dystrophic skin changes, ulceration, bleeding, and pain.and pain. Stage IVStage IV, the patient has high-output cardiac failure., the patient has high-output cardiac failure.
  15. 15. High-flow Vascular MalformationsHigh-flow Vascular Malformations
  16. 16. Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations Diagnosis: Diagnosis is typically clinical with an area of abnormality within skin,Diagnosis is typically clinical with an area of abnormality within skin, presenting as a pulsatile mass, thrill, warmth and rednesspresenting as a pulsatile mass, thrill, warmth and redness
  17. 17. Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations Imaging: Ultrasound: Diagnostic. Reveals multiple vascular channels with high flow and loss of normal venous damping on Doppler hhhhhh High flow characteristics post traumatic AVM
  18. 18. TREATMENTTREATMENT High-flow Malformations:High-flow Malformations: Surgical treatment:Surgical treatment: Small, superficial arteriovenous malformations can be removed surgically. However according to Szilagy (editor of Journal of vascular surgery) with few exceptions ,AVM cure by surgical means is impossible. Out of 82 patients with AVM , only 18 were suitable for operation. At FU, 6 were improved and 12 were worse. Embolization:Embolization: It has been the only feasible treatmentIt has been the only feasible treatment option for most arteriovenous malformations.option for most arteriovenous malformations. Embolization, which closes off the arterial feeders ofEmbolization, which closes off the arterial feeders of the malformation, is generally effective in arteriovenousthe malformation, is generally effective in arteriovenous malformations to stabilize the malformation.malformations to stabilize the malformation.
  19. 19. Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations Treatment No agreement on the protocols for treatment. Best method to access and treat AVM. The most single dominator for treatment is operator experience. A number of access route is available: -Trans arterial: most common used with grade 2,3&4 -direct stick: with type 1, slow venous flow -Transvenous: if there is a single draining vein, small nidus
  20. 20. Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations Treatment Embolic agents: No unified agreement on agent of choice. Depends on: Experience. Availability, location, morphology Wide range of agents : Particulate Gel foam. PVA .EmbospheresParticulate Gel foam. PVA .Embospheres Coils 035.018.controlled releaseCoils 035.018.controlled release Liquids Alcohol.Alcohol/Lipiodol.GlueLiquids Alcohol.Alcohol/Lipiodol.Glue Sclerosants STD.PolidocanolSclerosants STD.Polidocanol GlueGlue Detachable balloonsDetachable balloons Occlusion devices. PlugsOcclusion devices. Plugs
  21. 21. 035coils Polyvinyl Alcohol
  22. 22. Vascular Malformations:Vascular Malformations: High-flow Vascular MalformationsHigh-flow Vascular Malformations Treatment Onyx: Ethylene vinyl alcohol copolymer, relatively new non adhesive liquid agent that contains tantalum for radio opacity. It precipitates on contact with aqueous solution. It is the most useful for type2,3 and 4. in our practice >90% of AVMs are treated with Onyx. As the Flow dynamics of onyx has the greatest potential to occlude the AVM nidus
  23. 23. Goal of the treatment Artery Vein
  24. 24. Glue occlusion mechanism NBCA solidification obeys the polymerization law Contact with blood Time of polymerization depends of 3 major variables: Liquid Temperature Volume of Lipiodol Speed of injection Polymerization phenomenon = sticking phenomenon
  25. 25. Artery Vein Sticking Fragmentation Glue occlusion mechanism
  26. 26. Usual situation Proximal occlusion Glue occlusion mechanism
  27. 27. Dangerous situation Glue occlusion mechanism
  28. 28. Constitution: Ethylene vinyl alcohol (EVOH) resin Dimethyl sulfoxide (DMSO( Tantalum powder Onyx solidification obeys the precipitation law Onyx occlusion mechanism
  29. 29. Onyx fills the vessel in a concentric way Onyx progression obeys to the resistance variation law
  30. 30. R R R R R=8nl/r4Poiseuil
  31. 31. Transarterial embolization with Onyx. Multiple sessions
  32. 32. AVM of the hand. Slow venous filling. Direct stick with Foam. Marked reduction in nidus filling. Resolution of symptoms
  33. 33. Challenges of the treatment:Challenges of the treatment: Strategy.Strategy. Number of sessions: 6-8 weeksNumber of sessions: 6-8 weeks when to stop at each sessionwhen to stop at each session
  34. 34. Techniques to improve embolizationTechniques to improve embolization Pressure cooker technique Dual catheter technique
  35. 35. Simple catheter techniqueSimple catheter technique Hope
  36. 36. DangerDanger Hope Enlargement Remnant Ischemia Hides the remnanthemorrhage
  37. 37. Double catheter techniqueDouble catheter technique FirstFirst
  38. 38. Double catheter techniqueDouble catheter technique SecondSecond
  39. 39. 35 Y.O. Female35 Y.O. Female Frontal and supraorbital AVMFrontal and supraorbital AVM 3 endovascular treatments using glue in 20003 endovascular treatments using glue in 2000 followed by Radiosurgery (Gama Knife) in 2001followed by Radiosurgery (Gama Knife) in 2001 In 2008, 7 years later, new seizureIn 2008, 7 years later, new seizure AngiogramAngiogram
  40. 40. Right ECARight ECA
  41. 41. Middle meningeal artery navigationMiddle meningeal artery navigation (ECA)(ECA) Microcatheter 1Microcatheter 1
  42. 42. CM selective injection Microcatheter 1
  43. 43. Frontal artery navigation (ICA)Frontal artery navigation (ICA) Microcatheter 2Microcatheter 2
  44. 44. CM selective injection Microcatheter 2
  45. 45. Cath. 1 Cath. 2 Cath. 1 Cath. 2
  46. 46. Both microcatheters tips before Onyx injectionBoth microcatheters tips before Onyx injection
  47. 47. Onyx intranidal difusionOnyx intranidal difusion veine veine
  48. 48. Nidal remnant after Onyx injection andNidal remnant after Onyx injection and micro catheters retrievalmicro catheters retrieval
  49. 49. Glue injection(GlubranGlue injection(Glubran(:(:
  50. 50. Final controlFinal control::
  51. 51. Pressure cooker technique:Pressure cooker technique: Using coil+ or glue, then inject onyxUsing coil+ or glue, then inject onyx for deep penetrationfor deep penetration
  52. 52. ConclusionConclusion --Treatment of peripheral AVM is challenging andTreatment of peripheral AVM is challenging and requires a multidisciplinary team.requires a multidisciplinary team. -experience and understanding the capabilities and-experience and understanding the capabilities and physics of the embolic agent will determine thephysics of the embolic agent will determine the success of treatment.success of treatment. -Embolization is proving effective as a stand alone-Embolization is proving effective as a stand alone option with the proper use of the controlled liquidoption with the proper use of the controlled liquid embolic agents.embolic agents.