1. Essentials of Diagnosis
• Commonly noted at birth and confused with a hemangioma or a capillary malformation
• Eventually local warmth and pulsation lead to diagnosis
• Not easily compressible
• Overlying skin changes usually precede heart failure
2. General Considerations
Arteriovenous malformations, excluding intracranial lesions, are uncommon and are most often found in the head and neck Arteriovenous malformations are sometimes referred to as “fast-flow” lesions. Trauma or the onset of puberty may precipitate a growth of the malformation. An arteriovenous malformation is a diffuse lesion with a myriad of microscopic and macroscopic components. In contrast, an arteriovenous fistula is a smaller, more localized shunt from a large artery to nearby veins. Despite their different manifestations, arteriovenous fistulas fall within the broad grouping of arteriovenous malformations.
Clinical Findings Lesions are staged in four categories
Clinical suspicion is easy to confirm with ultrasound or color Doppler. Either MRI or MRA (magnetic resonance angiography) is the best modality to visualize the extent of the lesion. Arteriography is often reserved for the eventual treatment phase.
3. Differential Diagnosis
Arteriovenous malformations are commonly noted at birth but are confused with hemangiomas or capillary malformations. Ultrasound can differentiate these lesions
Congestive heart failure may necessitate urgent embolization. Echocardiography should be used to evaluate patients in Stage III and at least yearly thereafter to screen for progression to Stage IV
Ligating a large feeding vessel is always contraindicated. This procedure shifts the blood flow to collateral vessels and serves only to accelerate the growth of the malformation.
Complete surgical excision is the only way to ensure a permanent, successful treatment. With early diagnosis, surgical excision of a stage I malformation is possible. Early lesions have a greater chance for complete and successful surgical excision. However, because of late diagnosis or the risk of excising large lesions, patients are often followed until symptoms dictate intervention. Super-selective arterial embolization using permanent material can be used palliatively to relieve pain or other symptoms, or as part of a combined treatment plan intended to completely eliminate the lesion. These combined treatments usually consist of either serial embolization followed by surgical resection, which is most commonly used, or embolization followed by sclerotherapy. If the overlying skin is normal, it can be saved; however, this is often not the case. Long-term follow-up is essential as these lesions have a tendency for recurrence even when treated by an experienced physician.
Breugem CC, van der Horst CMAM, Hennekam RCM. Progress toward understanding vascular malformations. Plast Reconstr Surg. 2001;107:1509. [PMID: 11335828] (A detailed review of the current understanding of the pathogenesis of these birth defects.)
Kohout MP, Hansen M, Pribaz JJ, Mullkien JB. Arteriovenous malformations of the head and neck: natural history and management. Plast Reconstr Surg. 1998;102:643. [PMID: 9727427] (A description of the treatment outcome of 81 patients.)