Chapter 171 - Congenital vascular malformations general considerations

Question 1

Definition of congenital vascular malformation

Answer 1

Malformed vessels resulted from arrested development during various stages of embryogenesis Present at birth but not always immediately identifiable

Question 2

types of congenital vascular malformation

Answer 2

affect arterial, venous and lymphatic either as predominant form or mixed form continue to grow

Question 3

Hemangioma key points

Answer 3

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)

Question 4

Old terms for congenital vascular malformation

Answer 4

1) angiodysplasia 2) cavernous hemangioma (misnomer now) 3) cystic hygroma 4) lymphangioma

Question 5

Eponyms types of congenital vascular malformation

Answer 5

1) Klippel-Trenaunay 2) Parkes-Weber

Question 6

Hamburg classification

Answer 6

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

Question 7

Hamburg class for embryologic subtypes

Answer 7

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)

Question 8

ISSVA/Mulliken classification

Answer 8

International society for the study of vascular anomalies 1) fast-flow lesions 2) slow-flow lesions

Question 9

Incidence of congenital vascular malformations (CVM)

Answer 9

1.08% (0.83 - 4.5%) VM/AVM 0.45% CM 0.42% LM 0.14% mixed 0.34%

Question 10

Epidemiology of CVM

Answer 10

male:female 1:1 VM most frequent in extratruncular type

Question 11

Deep venous anomaly in vascular malformation

Answer 11

36% phlebectasia 8% hypoplasia/aplasia 8% venous aneurysms

Question 12

Causes of CVM

Answer 12

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

Question 13

Cellular level of CVM development

Answer 13

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

Question 14

Origin of embryonic blood vessels

Answer 14

Blood island of Pander: masses of vasoformative cells

Question 15

How embryonic blood vessels form

Answer 15

Undifferentiated capillary plexus –> vasculature Capillaries regress –> reticular structure (extratruncular stage) Truncular stage = formation of artery vein lymphatic trunks

Question 16

How to differentiate between truncular vs extratruncular stages in arrest development

Answer 16

Defects before truncular stage maintains embryonic characteristics of mesenchymal cells

Question 17

Extratruncular lesion key points

Answer 17

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

Question 18

What can a mesoderm give rise to

Answer 18

1) bones 2) muscle 3) soft tissue 4) blood vessels

Question 19

Truncular lesions key points

Answer 19

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

Question 20

CVM pathophysiological significance two types

Answer 20

1) mechanical impact on surrounding structure 2) hemodynamic impact on circulation

Question 21

example of secondary organ impact of CVM

Answer 21

1) intraosseous CVM stimulate epiphyseal plate 2) abnormal long-bone growth, leg length discrepancy

Question 22

capillary malformation clinical presentation

Answer 22

Port wine stain Different from nevus flammeus neonatorum because CM can occur anywhere

Question 23

Sturge-Weber syndrome

Answer 23

Intracranial CVM with ipsilater ocular and leptomeningeal vascular malformation

Question 24

Common areas of venus flammeus neonatorum

Answer 24

Birth mark 1) nuchal (stork bite) 2) face: eyelid, forehead, lips (angel’s kiss)

Question 25

Venous malformation clinical presentation

Answer 25

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

Question 26

Lymphatic malformation clinical presentation

Answer 26

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

Question 27

Gorham syndrome

Answer 27

pathologic fracture of long bone caused by lymphatic malformation affecting bone metabolism

Question 28

Arteriovenous malformation clinical presentation

Answer 28

1) swelling, signs of shunting 2) ischemia 3) high output cardiac failure

Question 29

Combined vascular malformation (hemolymphatic malformation) clinical presentation

Answer 29

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

Question 30

marginal vein malformation in KTS and other CVM

Answer 30

Lateral marginal vein of Servelle

Question 31

Diagnostic tests for congenital vascular malformation

Answer 31

BOX 171.2

Question 32

Whole body blood pool scintigraphy define

Answer 32

WBBPS transvenous angioscan with radioisotope-tagged RBC detect small amounts of abnormal blood pooling

Question 33

non-invasive test for venous malformation diagnosis

Answer 33

T2-weighted MRI

Question 34

non-invasive for lymphatic malformation diagnosis

Answer 34

Radioisotope lymphoscintigraphy

Question 35

non-invasive for AVM diagnosis

Answer 35

CT with 3D recon

Question 36

Lymphangiography not used often because

Answer 36

Damage to lymphatic vessels from oil-based contrast inflammation

Question 37

Hemangioma main points

Answer 37

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

Question 38

Indication to treat extratruncular congenital vascular malformation

Answer 38

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

Question 39

Congenital vascular bone syndrome

Answer 39

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

Question 40

Klippel-Trenaunay syndrome key points

Answer 40

1) Port wine stain 2) limb hypertrophy/gigantism 3) large clusters of varicose veins 4) lateral venous collector (Marginal vein)

Question 41

Treatment of KTS

Answer 41

1) compression 35-45 mm pressure 2) sclerotherapy 3) excision (ensure deep vein present)

Question 42

Parkes Weber syndrome key points

Answer 42

1) first described in 1907 similar to KTS 2) varicose veins 3) limb hypertrophy 4) port wine stain 5) detectable pulsation and thrill (AVM)

Question 43

Treatment of PWS

Answer 43

1) like KTS 2) embolization

Question 44

Localized intravascular coagulopathy (LIC)

Answer 44

Stasis of blood within abnormal structures –> activated coagulation cascade –> fibrinolysis (elevated D-dimer) –> phleboliths (microthrombi)

Question 45

Treatment for localized intravascular coagulopathy

Answer 45

LMWH to prevent DIC, PE, hemorrhage along with surgical resection options

Question 46

Follow up for CVM

Answer 46

Long term routine pre- and post-treatment due to recurrence and potential to become threatening