Chapter 171 - Congenital vascular malformations general considerations Flashcards
Definition of congenital vascular malformation
Malformed vessels resulted from arrested development during various stages of embryogenesis Present at birth but not always immediately identifiable
types of congenital vascular malformation
affect arterial, venous and lymphatic either as predominant form or mixed form continue to grow
Hemangioma key points
1) Vascular tumor originates from endothelial cells 2) appear early in neonatal, grows then involutes by age 12 3) not congenital vascular malformations (CVM never regress)
Old terms for congenital vascular malformation
1) angiodysplasia 2) cavernous hemangioma (misnomer now) 3) cystic hygroma 4) lymphangioma
Eponyms types of congenital vascular malformation
1) Klippel-Trenaunay 2) Parkes-Weber
Hamburg classification
1988 Germany consensus from 7th International Workshop on Vascular Malformation Updated in 1992/1996 to add capillary 1) Arterial 2) Venous 3) Arteriovenous shunting 4) Lymphatic 5) Hemolymphatic (combined) 6) Capillary
Hamburg class for embryologic subtypes
Extratruncular forms 1) infiltrating, diffuse 2) limited, localized Trucular forms 1) stenosis or obstruction: hypoplasia, aplasia, hyperplasia, membrane, congenital spur 2) dilation: localized (aneurysm), diffuse (ectasia)
ISSVA/Mulliken classification
International society for the study of vascular anomalies 1) fast-flow lesions 2) slow-flow lesions
Incidence of congenital vascular malformations (CVM)
1.08% (0.83 - 4.5%) VM/AVM 0.45% CM 0.42% LM 0.14% mixed 0.34%
Epidemiology of CVM
male:female 1:1 VM most frequent in extratruncular type
Deep venous anomaly in vascular malformation
36% phlebectasia 8% hypoplasia/aplasia 8% venous aneurysms
Causes of CVM
1) exposure to damaging chemicals during 1st trimester 2) infections: rubella, cytomegalic inclusion disease, herpes, toxoplasmosis 3) thalidomide, aminopterin, cyclophosphamide, quinine, anticonvulsant, cortisone, corticotropin 4) alcohol, tobacco, cocaine 5) maternal disease: goiter, DM, thyroid, tb, hypoxia, carbonmonixide and lead poisoning
Cellular level of CVM development
Mutation of TEK –> loss of TIE2 receptor –> upregulate expression of betaTGF, betaFGF –> VM VEGF induced defective response of endothelial cells TIE2/TEK receptor on chromosome 9p21 HLA locus on chromosome 6p21.32 Increase expression of matrix metalloproteinase-9
Origin of embryonic blood vessels
Blood island of Pander: masses of vasoformative cells
How embryonic blood vessels form
Undifferentiated capillary plexus –> vasculature Capillaries regress –> reticular structure (extratruncular stage) Truncular stage = formation of artery vein lymphatic trunks
How to differentiate between truncular vs extratruncular stages in arrest development
Defects before truncular stage maintains embryonic characteristics of mesenchymal cells
Extratruncular lesion key points
1) arrested during early embryonic life in reticular stage 2) mesodermal origin retain mesenchymal cells (Angioplast) retain ability to proliferate when stimulated (menarche, pregnancy, trauma) 3) higher recurrence than truncular 4) mechanical and hemodynamic impacts
What can a mesoderm give rise to
1) bones 2) muscle 3) soft tissue 4) blood vessels
Truncular lesions key points
1) arrested during vascular trunk formation 2) lost embryonic characteristics and potential to proliferate 3) less recurrence risk as extratruncular but higher hemodynamic consequence 4) mainly hemodynaimc impact
CVM pathophysiological significance two types
1) mechanical impact on surrounding structure 2) hemodynamic impact on circulation
example of secondary organ impact of CVM
1) intraosseous CVM stimulate epiphyseal plate 2) abnormal long-bone growth, leg length discrepancy
capillary malformation clinical presentation
Port wine stain Different from nevus flammeus neonatorum because CM can occur anywhere
Sturge-Weber syndrome
Intracranial CVM with ipsilater ocular and leptomeningeal vascular malformation
Common areas of venus flammeus neonatorum
Birth mark 1) nuchal (stork bite) 2) face: eyelid, forehead, lips (angel’s kiss)
Venous malformation clinical presentation
1) bluish swelling near skin 2) compressible, enlarge with valsalva 3) collapsable when elevated 4) slow growing 5) respond to compression 6) secondary symptoms possible 7) dental, facial, long bone malformation 8) abnormal gait 9) GI bleed 10) PE
Lymphatic malformation clinical presentation
1) diffuse (primary lymphedema) 2) localized swelling (lymphangioma) 3) facial asymmetry, overgrowth, pain 4) pathologic fracture of long bone caused by lymphatic malformation affecting bone metabolism
Gorham syndrome
pathologic fracture of long bone caused by lymphatic malformation affecting bone metabolism
Arteriovenous malformation clinical presentation
1) swelling, signs of shunting 2) ischemia 3) high output cardiac failure
Combined vascular malformation (hemolymphatic malformation) clinical presentation
1) overgrowth of soft/skeletal tissue 2) port wine stain from lateral leg to buttock/thorax 3) variation skin color with vesicles that could leak/infected 4) limb swelling due to lymphedema or marginal vein swelling 5) vascular bone syndrome: soft tissue and skeletal hypertrophy/hypotrophy 6) non-extremity vascular symptoms
marginal vein malformation in KTS and other CVM
Lateral marginal vein of Servelle
Diagnostic tests for congenital vascular malformation
BOX 171.2
Whole body blood pool scintigraphy define
WBBPS transvenous angioscan with radioisotope-tagged RBC detect small amounts of abnormal blood pooling
non-invasive test for venous malformation diagnosis
T2-weighted MRI
non-invasive for lymphatic malformation diagnosis
Radioisotope lymphoscintigraphy
non-invasive for AVM diagnosis
CT with 3D recon
Lymphangiography not used often because
Damage to lymphatic vessels from oil-based contrast inflammation
Hemangioma main points
1) not present at birth 2) appear suddenly during neonatal then involute 3) more common in females 3-5:1 CVM grows with patient and gender distribution is equal Tissue biopsy is rarely needed to differentiate Use non-invasive imaging
Indication to treat extratruncular congenital vascular malformation
1) hemorrhage 2) high output heart failure (AV shunt) 3) secondary ischemia (AV shunt) 4) secondary venous hypertension (VM) 5) life or vital function- threatening lesion location 6) disabling pain 7) functional impairment 8) cosmetically severe deformity 9) vascular bone syndrome 10) high potential location for complications 11) lymph leak +/- infection 12) recurrent sepsis
Congenital vascular bone syndrome
1) abnormal circulation around or in bone cause angio-osteo-hypertrophy or hypotrophy 2) Marginal vein can cause this 3) limb overgworth: hypervascularization with macro or micro-shunts 4) limb undergrowth: bone compression due to mass or reduced arterial inflow
Klippel-Trenaunay syndrome key points
1) Port wine stain 2) limb hypertrophy/gigantism 3) large clusters of varicose veins 4) lateral venous collector (Marginal vein)
Treatment of KTS
1) compression 35-45 mm pressure 2) sclerotherapy 3) excision (ensure deep vein present)
Parkes Weber syndrome key points
1) first described in 1907 similar to KTS 2) varicose veins 3) limb hypertrophy 4) port wine stain 5) detectable pulsation and thrill (AVM)
Treatment of PWS
1) like KTS 2) embolization
Localized intravascular coagulopathy (LIC)
Stasis of blood within abnormal structures –> activated coagulation cascade –> fibrinolysis (elevated D-dimer) –> phleboliths (microthrombi)
Treatment for localized intravascular coagulopathy
LMWH to prevent DIC, PE, hemorrhage along with surgical resection options
Follow up for CVM
Long term routine pre- and post-treatment due to recurrence and potential to become threatening
