Vascular Surgery for Arteriovenous Malformations

Updated: Mar 17, 2023
  • Author: Allison Leigh Speer, MD; Chief Editor: Vincent Lopez Rowe, MD, FACS  more...
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Practice Essentials

An arteriovenous malformation (AVM) is a defect in the vascular system in which a tangle of abnormal blood vessels directly connects the feeding arteries to a venous drainage network without the interposition of a capillary bed. [1]

Vascular anomalies are among the most common congenital abnormalities in infants and children. Historically, their treatment has been impeded by confusing terminology and imprecise classification. Lesions were named with descriptive terms (eg, strawberry hemangioma or port-wine stain) or histopathologic terms (eg, capillary hemangioma, cavernous hemangioma, or lymphangioma). Although some vascular anomalies may appear similar, their biologic behavior differs markedly; therefore, treatment should be based on a proper classification system. [2, 3]


Classification of vascular anomalies is based on the landmark 1982 paper by Mulliken and Glowacki, which proposed a simplified categorization of these anomalies that was based on biologic activity. [4] As a result, the following two main types of vascular anomalies are generally recognized:

Differentiating between these two types of anomalies is essential because their treatment is quite different. The management of vascular anomalies is a dynamic and rapidly developing subspecialty, which requires interdisciplinary care and collaboration.

During its 1996 workshop, the International Society for the Study of Vascular Anomalies (ISSVA) adopted a classification system designed to provide a common language for guiding treatment. It was based on Mulliken and Glowacki’s biologic study but also further distinguished vascular malformations according to hemodynamics and predominant anomalous channels. [5, 6, 7, 8] At its 20th workshop in 2014, the ISSVA approved a revised classification, [9] which was further revised at the ISSVA General Assembly in May 2018 (see Table 1 below). [10]

Table 1. ISSVA Classification of Vascular Anomalies (May 2018 Revision) (Open Table in a new window)

Vascular Tumors Vascular Malformations

Benign vascular tumors

Infantile hemangioma/hemangioma of infancy

Congenital hemangioma

  • Rapidly involuting (RICH)
  • Noninvoluting (NICH)
  • Partially involuting (PICH)

Tufted angioma

Spindle-cell angioma

Epithelioid angioma

Pyogenic granuloma (lobular capillary hemangioma)


Related lesions

Simple vascular malformations

Capillary malformation (CM)

  • Nevus simplex/salmon patch, "angel kiss," "stork bite"
  • Cutaneous/mucosal CM (port-wine stain)
  • Reticulate CM
  • CM of CM-AVM (arteriovenous malformation)
  • Cutis marmorata telangiectatica congenita (CMTC)
  • Others
  • Telangiectasia (hereditary hemorrhagic telangiectasia [HHT], others)

Lymphatic malformation (LM)

  • Common (cystic) LM (macrocystic, microcystic, mixed cystic)
  • Generalized lymphatic anomaly (GLA) (kaposiform lymphangiomatosis [KLA])
  • LM in Gorham-Stout disease
  • Channel-type LM
  • "Acquired" progressive lymphatic anomaly (acquired progressive "lymphangioma")
  • Primary lymphedema
  • Others

Venous malformation (VM)

  • Common VM
  • Familial VM cutaneomucosal (VMCM)
  • Blue rubber bleb nevus (Bean) syndrome VM
  • Glomuvenous malformation (GVM)
  • Cerebral cavernous malformation (CCM)
  • Familial intraosseous vascular malformation (VMOS)
  • Verrucous venous malformation (formerly verrucous hemangioma)
  • Others

Arteriovenous malformation (AVM)

  • Sporadic
  • In HHT
  • In CM-AVM
  • Others

Arteriovenous fistula (AVF) (congenital)

  • Sporadic
  • In HHT
  • In CM-AVM
  • Others

Locally aggressive or borderline vascular tumors

Kaposiform hemangioendothelioma

Retiform hemangioendothelioma

Papillary intralymphatic angioendothelioma (PILA), Dabska tumor

Composite hemangioendothelioma

Pseudomyogenic hemangioendothelioma

Polymorphous hemangioendothelioma

Hemangioendothelioma not otherwise specified

Kaposi sarcoma


Combined vascular malformations









Malignant vascular tumors


Epithelioid hemangioendothelioma


Anomalies of major named vessels (channel-type or truncal vascular malformations)


  • Lymphatics
  • Veins
  • Arteries

Anomalies of

  • Origin
  • Course
  • Number
  • Length
  • Diameter
  • Valves
  • Communication (AVF)
  • Persistence (of embryonal vessel)

Vascular malformations associated with other anomalies

Klippel-Trenaunay syndrome

Parkes Weber syndrome

Servelle-Martorell syndrome

Sturge-Weber syndrome

Limb CM + congenital nonprogressive limb overgrowth

Maffucci syndrome



CLOVES syndrome

Proteus syndrome

Bannayan-Riley-Ruvalcaba syndrome

CLAPO syndrome

C = capillary, V = venous, L = lymphatic, A = arterial, M = malformation, F = fistula.  

A few vascular anomalies remained provisionally unclassified. [10] Additional information is available on the ISSVA Web site.



The pathogenesis of AVMs is not well understood [11, 1] but is thought to involve abnormal vasculogenesis. Multiple biologic studies since 1982 have demonstrated clear differences between vascular tumors (hemangiomas) and vascular malformations. Some have hypothesized that infantile hemangiomas result from excess angiogenesis, whereas vascular malformations are due to errors in vessel remodeling. [12] Although some vascular malformations thicken, expand, or multiply with time, it is unclear whether true angiogenesis occurs.

Marler et al suggested that vascular malformations may be angiogenesis-dependent disorders. They found that urinary high-molecular-weight matrix metalloproteinases (hMW MMPs) and basic fibroblast growth factor (bFGF) levels are elevated in vascular tumors and some vascular malformations (eg, lymphatic malformations [LMs], lymphaticovenous malformations [LVMs], and AVMs) and that the urinary increase in these proteins parallels the tissue remodeling seen in diffuse and expanding vascular malformations. [13] They suggested that drugs targeting bFGF or MMPs may be an adequate therapeutic strategy for patients suffering from these vascular anomalies.

Inherited forms of vascular malformations are rare [6] but may offer insight into the molecular mechanisms and signaling pathways involved in the pathogenesis of these lesions. This may in turn identify potential novel therapeutic targets, though at present, it is unclear whether the more common sporadic vascular malformations share similar biologic mechanisms with the infrequent inherited vascular malformations.

An AVM is a hemodynamically active fast-flow vascular malformation. [14] Arterial feeders and enlarged draining veins directly connect through micro- and macroarteriovenous fistulas that create the nidus or epicenter of the AVM. AVMs may occur both superficially and viscerally. They are usually present at birth and rarely regress. [6] They have a normal endothelial cell cycle and grow commensurately with the child. [4, 2]

The natural history of AVMs may be organized according to the clinical staging system proposed by Schobinger at the 1990 ISSVA meeting in Amsterdam (see Table 2 below). [15]

Table 2. Schobinger Staging for AVMs (Open Table in a new window)



I - Quiescence

Pink-bluish stain, warmth, and arteriovenous shunting are revealed by Doppler scanning. The arteriovenous malformation mimics a capillary malformation or involuting hemangioma.

II - Expansion

The description is the same as stage I, plus enlargement, pulsations, thrill, and bruit and tortuous/tense veins.

III - Destruction

The description is the same as stage II, plus dystrophic skin changes, ulceration, bleeding, persistent pain, or tissue necrosis. Bony lytic lesions may occur.

IV - Decompensation

The description is the same as stage III, plus congestive cardiac failure with increased cardiac output and left ventricle hypertrophy.

Some authors, citing case reports describing "de novo" brain AVMs, have suggested that some of these AVMS may develop some time after birth as a result some kind of "second hit" (eg, from a previous intracranial hemorrhage or vascular pathology). [16]



Although vascular anomalies are among the most common pediatric abnormalities, occurring in approximately 1% of children, [17] AVMs are rare. [6]

Most AVMs are evident at birth (40% in a study of 200 AVMs by Enjolras et al), [18] though they may not be clinically relevant. Mulliken and Glowacki noted that 90% of vascular malformations were present at birth in a series of 23 patients; however, these lesions were predominantly venous in type and may not be representative of AVMs per se. [4]

The female-to-male ratio for vascular malformations is 1:1. [4, 18]



AVMs never regress and usually follow the stages outlined by Schobinger (see Pathophysiology). Morbidity and mortality are dependent on several factors, as follows:

  • Location and size of the AVM
  • Whether the AVM is surgically accessible or amenable to palliative embolization/sclerotherapy
  • Presence or absence of congestive heart failure

The prognosis is excellent when AVMs are managed by an interdisciplinary team, and the best success is achieved in surgically accessible lesions treated with combined embolization and complete surgical resection. (See the image below.)

Panel A: 12-year-old female with right facial arte Panel A: 12-year-old female with right facial arteriovenous malformation (AVM) s/p sclerotherapy. Panel B: 12.5-year-old female 4 months after resection of right facial AVM with preoperative embolization, complex closure, and lip reconstruction with rotational advancement flaps. Panel C: 13-year-old female with good recovery and no residual palpable or pulsatile AVM. Panel D: 14-year-old female with regrowth of AVM after the onset of puberty.