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- See also: Cerebral arteriovenous malformation
| Arteriovenous malformation Classification and external resources |
|
| ICD-10 | Q27.3, Q28.0, Q28.2 |
|---|---|
| ICD-9 | 747.6, 747.81 |
| DiseasesDB | 15235 |
| MedlinePlus | 000779 |
| eMedicine | topic list |
| MeSH | D001165 |
Arteriovenous malformation or AVM in the majority of cases is a congenital disorder consisting on a connection between veins and arteries, this pathology is universally known of its occurrence in the central nervous system, but can appear in any location.
The genetic transmission patterns of AVM -if any- are unknown, and AVM is not generally thought to be an inherited disorder, unless in the context of a specific hereditary syndrome.
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Signs and symptoms
Symptoms of AVM vary according to the location of the malformation. Roughly (88% -needs citation) AVM are asymptomatic; often the malformation is discovered as part of an autopsy or during treatment of an unrelated disorder (called in medicine an incidental finding), rarely its expansion or a micro-bleed from it, could cause epilepsy, deficit or elicit pain.
The most general symptoms include headache and epilepsy, with more specific symptoms occurring that normally depend on the location of the malformation and the individual. Other possible symptoms include:[1]
- Difficulties with movement or coordination, including muscle weakness and even paralysis;
- vertigo (dizziness);
- Difficulties of speech (dysarthria) and communication, such as alogia;
- Difficulties with everyday activities, such as apraxia;
- Abnormal sensations (numbness, tingling, or spontaneous pain);
- Memory and thought-related problems, such as confusion, dementia or hallucinations.
Pathophysiology
Arteries and veins are part of the human cardiovascular system. Normally, the arteries in the vascular system carry oxygen-rich blood. Structurally, arteries divide and sub-divide repeatedly, eventually forming a sponge-like capillary bed. Blood moves through the capillaries, giving up oxygen and taking up waste products from the surrounding cells (CO2). Capillaries successively join together, one upon the other, to form veins that carry blood away. The heart acts to pump blood through arteries and uptake the venous blood.
If the capillary bed is thought of as a sponge, then an AVM is the rough equivalent of jamming a tangle of flexible soda straws from artery to vein through that sponge. On arteriogram films AVM formation often resemble a tangle of spaghetti noodles. This tangle of blood vessels forms a relatively direct connection between high pressure arteries and low pressure veins.
The result is a collection of blood vessels with abnormal connections and no capillaries. This collection, often called a nidus, can be extremely fragile and prone to bleeding.
Diagnosis
AVMs can occur in various parts of the body
- brain, causing a cerebral arteriovenous malformation
- spleen[2]
- lung[3]
- kidney[4]
- spinal cord[5]
- liver[6]
- intercostal space[7]
- iris[8]
- spermatic cord[9]
AVMs may occur in isolation or as a part of another disease (e.g. Von Hippel-Lindau disease or hereditary hemorrhagic telangiectasia).
This bleeding can be devastating, particularly in the brain. It can cause severe and often fatal strokes. If detected before a stroke occurs, usually the arteries feeding blood into the nidus can be closed off, ensuring the safety of the patient.
Treatment
Treatment can be symptomatic, or it can involve surgery or radiation therapy.[1]
Epidemiology
An estimated 300,000 Americans have AVMs, of which 12% (approximately 36,000) will exhibit symptoms that differ greatly in severity.[1]
Society and culture
- On December 13, 2006, Senator Tim Johnson was diagnosed with AVM and treated at George Washington University Hospital.[10]
Cases in fiction
- The plot of William Finn's 1998 Off-Broadway musical, A New Brain, revolves around the main character's battle with AVM.
- The character Nate Fisher on the HBO television show Six Feet Under suffers from AVM.
- Patients with AVM appeared in two episodes of the series House, DNR, fictional British medical show Harley Street.
Research directions
Despite many years of research, the central question of whether to treat AVMs has not been answered. All treatments, whether involving surgery or drugs, have risks and side-effects. Therefore it might be better in some cases to avoid treatment altogether and simply accept a small risk of coming to harm from the AVM itself. This question is currently being addressed in clinical trials[11].
References
- ^ a b c Arteriovenous Malformation Information Page at NINDS
- ^ Agrawal A, Whitehouse R, Johnson RW, Augustine T (December 2006). "Giant splenic artery aneurysm associated with arteriovenous malformation". J. Vasc. Surg. 44 (6): 1345–9. doi:. PMID 17145440. Retrieved on 2008-06-01.
- ^ Chowdhury UK, Kothari SS, Bishnoi AK, Gupta R, Mittal CM, Reddy S (February 2008). "Successful Lobectomy for Pulmonary Arteriovenous Malformation Causing Recurrent Massive Haemoptysis". Heart Lung Circ. doi:. PMID 18294908. Retrieved on 2008-06-01.
- ^ Barley FL, Kessel D, Nicholson T, Robertson I (2006). "Selective embolization of large symptomatic iatrogenic renal transplant arteriovenous fistula". Cardiovasc Intervent Radiol 29 (6): 1084–7. doi:. PMID 16794894.
- ^ Kishi K, Shirai S, Sonomura T, Sato M (March 2005). "Selective conformal radiotherapy for arteriovenous malformation involving the spinal cord". Br J Radiol 78 (927): 252–4. PMID 15730991.
- ^ Bauer T, Britton P, Lomas D, Wight DG, Friend PJ, Alexander GJ (May 1995). "Liver transplantation for hepatic arteriovenous malformation in hereditary haemorrhagic telangiectasia". J. Hepatol. 22 (5): 586–90. PMID 7650340. Retrieved on 2008-06-01.
- ^ Rivera PP, Kole MK, Pelz DM, Gulka IB, McKenzie FN, Lownie SP (November 2006). "Congenital intercostal arteriovenous malformation". AJR Am J Roentgenol 187 (5): W503–6. doi:. PMID 17056881.
- ^ Shields JA, Streicher TF, Spirkova JH, Stubna M, Shields CL (March 2006). "Arteriovenous malformation of the iris in 14 cases". Arch. Ophthalmol. 124 (3): 370–5. doi:. PMID 16534057.
- ^ Sountoulides P, Bantis A, Asouhidou I, Aggelonidou H (2007). "Arteriovenous malformation of the spermatic cord as the cause of acute scrotal pain: a case report". J Med Case Reports 1: 110. doi:. PMID 17939869.
- ^ "Sen. Johnson recovering after brain surgery", AP, December 14, 2006.
- ^ Research trials in arterio-venous malformations; Rustam Al-Shahi Salman
External links
- AVM Support Groups from the DMOZ Open Directory.
- University of California San Francisco AVM research.
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Wikipedia content modification information:
- This page was last modified on 28 September 2008, at 02:21.
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