Terminology

Preprocedure

Procedure

Outcomes

Definitions

• Vascular malformation (VMF): Most common vascular anomaly consisting of abnormal clusters of blood vessels without endothelial proliferation
  • Low flow: Capillary, venous, lymphatic or "mixed" malformations
    • Venous malformations (VM)
      • Most common type of VMF consisting of dilated venous vessels with abnormal smooth muscle, which allows for expansion of VM over time
      • May or may not communicate with systemic vasculature
      • Usually sporadic but can occur as part of genetic syndrome (e.g., Klippel-Trénaunay)
      • Diverse range of size, location, and appearance: From small, solitary, and localized to skin and subcutaneous tissues to diffuse masses extending across multiple tissue planes and surrounding vascular, nervous, and visceral bodies
    • Lymphatic malformation (LM)
      • 2nd most common VMF consisting of benign cystic lesions made up of lymphatic vessels filled with lymphatic fluid
      • Most commonly sporadic; however, some associated with genetic syndromes (e.g., Turner, Noonan)
      • Classified based on cyst size as macrocystic (large), microcystic (small), or mixed
      • Previously used terms such as lymphangiomas and cystic hygromas should be avoided
    • Capillary malformation (CM)
      • Limited to superficial skin layers, formerly called port-wine stains
      • Can darken, thicken, and become nodular if left untreated
      • Often associated with congenital syndrome (e.g., Sturge-Weber, Parkes Weber, Klippel-Trénaunay)
  • High flow: Direct communication between arteries and veins
    • Arteriovenous malformations (AVM)
      • Complex communicating network of arterial and venous vessels
      • Typically more invasive than other VMFs
      • Arterial inflow diverted via nidus into draining veins, causing tissue ischemia and venous hypertension
      • High recurrence rate after treatment with total nidus eradication considered "curative"
    • Arteriovenous fistula (AVF)
      • Direct abnormal communication between artery and vein without interposed nidus
      • Can be acquired (most common) or congenital
      • Limb ischemia can occur distal to AVF due to arterial blood shunted via fistula (steal phenomenon)
  • Syndromes associated with VMFs
    • Klippel-Trénaunay syndrome: VM combined with LM and CM
    • Parkes Weber syndrome: VM combined with LM, CM, and AVM
    • Sturge-Weber syndrome: Cutaneous CM along distribution of facial and ocular nerves; leptomeningeal vascular anomalies (CM, VM)

Classification

• International Society for the Study of Vascular Anomalies (ISSVA) classification (revised 2014)
  • Most widely recognized classification system based on cellular features, flow characteristics, associated clinical features and genetics
  • Defines common language used by all members of interdisciplinary teams involved in care of vascular anomalies
  • Broadly divides vascular anomalies into nonneoplastic lesions (VMFs) and neoplastic lesions (vascular tumors)
• SE Mitchell Vascular Anomalies Flow Chart (SEMVAFC)
  • Combines clinical and imaging findings for accurate VMF diagnosis
  • Utilizes classification schema similar to ISSVA to preserve common language
  • Potential to identify syndromes associated with VMF
• Yakes classification
  • Organizes AVMs by angioarchitecture and ascribes specific endovascular treatment options for each subtype

Low-Flow Malformations: Clinical Features

• Presentation & physical exam
  • VM
    • Present as soft, compressible, nonpulsatile, bluish lesions
    • Often present with pain, swelling, and depending on location, mechanical dysfunction or cosmetic disfigurement
    • Vary in size and distribution; potentially involves multiple anatomic locations
    • Majority are solitary but can be associated with genetic syndrome (e.g., blue rubber bleb nevus syndrome)
    • Can occur in any anatomic depth (i.e., skin, subcutaneous tissue, muscle, etc.) and are often infiltrative and extend to underlying or nearby structures
    • Placement of affected area in dependent position or Valsalva maneuver may elicit blood pooling and subsequent enlargement of lesion
    • Most commonly occur in head, neck, and extremities but can present anywhere on body
  • LM
    • Present as soft, nonpulsatile, uniocular or multilocular cystic lesions
    • Often present with swelling, and depending on location, mechanical dysfunction or cosmetic disfigurement
    • Can become swollen and painful when locally infected or with systemic infection
    • Vary in size from microcystic to macrocystic (> 1-2 cm) or mixed type
    • Can be isolated or associated with genetic syndrome (e.g., Turner, Noonan)
    • Most often present in head and neck, but chest, axilla, and perineum also common sites
  • CM
    • Present as pink-red patches but may darken, thicken, and become more nodular with time
    • Can be isolated or coexist with other VMFs, or associated with genetic syndrome (e.g., Kippel-Trénaunay, Sturge-Weber, Parkes Weber)
    • Physical exam and, in some cases, imaging should exclude underlying malformations

High-Flow Malformations: Clinical Features, Noncerebrovascular

• Presentation and physical exam
  • AVM
    • Present as warm, palpable mass with ill-defined border and reddish discoloration of overlying skin
    • Surrounding fat tissue most often present
    • Often accompanied by palpable thrill/bruit
    • Most commonly present in limbs, trunk, and viscera
    • Bleeding, ulceration of surrounding soft tissue and high-output heart failure in advanced stages
    • May cause "steal" from surrounding or downstream organs
    • May lead heart failure due to high cardiac output
  • AVF
    • Present as palpable, pulsatile mass often associated with bruit and perivascular thrill
    • Only congenital AVFs classified as VMFs: Most are acquired (e.g., traumatic or iatrogenic)
    • Congenital AVFs are rare, can occur anywhere in body and commonly manifest in infancy as high-output heart failure
    • Claudication, deep vein thrombosis, rest pain, and varicose veins may develop in extremities distal to lesion

Preprocedure Imaging

Getting Started

Treatments: Low-Flow Malformations

Treatments: High-Flow Malformations

Patient Position/Location

Equipment Preparation

Procedure Steps

Alternative Procedures/Therapies

Things to Do

Complications

Expected Outcomes