Arterial dissections

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Arterial dissections
Arterial Dissection.jpg
Aortic dissection
Specialty Vascular surgery

An arterial dissection is a tear within the wall of an artery, which allows blood to separate the wall layers. There are several types. Tears almost always occur in arterial walls, but a vein wall tear has been documented. [1]

Contents

By separating a portion of the wall of the artery (a layer of the tunica media or in some cases tunica intima), a tear creates two lumens or passages within the vessel, the original or true lumen, and the false lumen created by the new space within the wall of the artery. It is not yet clear if the tear in the innermost layer, the tunica intima, is secondary to the tear in the tunica media. Dissections originating in the tunica media are caused by disruption of the vasa vasorum. It is thought that dysfunction in the vasa vasorum is an underlying cause of dissections. [2]

Description

Arterial dissections become life-threatening when growth of the false lumen prevents perfusion of the true lumen and the related end organs. For example, in an aortic dissection, if the left subclavian artery orifice were distal to the origin of the dissection, then the left subclavian would be said to be perfused by the false lumen, while the left common carotid (and its end organ, the left hemisphere of the brain) if proximal to the dissection, would be perfused by the true lumen proximal to the dissection.

MRI of an aortic dissection
1 Aorta descendens with dissection
2 Aorta isthmus AoDiss MRT.jpg
MRI of an aortic dissection
1 Aorta descendens with dissection
2 Aorta isthmus

Vessels and organs that are perfused from a false lumen may be well-perfused to varying degrees, from normal perfusion to no perfusion. In some cases, little to no end-organ damage or failure may be seen. Similarly, vessels and organs perfused from the true lumen but distal to the dissection may be perfused to varying degrees. In the above example, if the aortic dissection extended from proximal to the left subclavian artery takeoff to the mid descending aorta, the common iliac arteries would be perfused from the true lumen distal to the dissection but would be at risk for malperfusion due to occlusion of the true lumen of the aorta by the false lumen.

Types

Examples include:

Carotid and vertebral artery dissection are grouped together as "Cervical artery dissection" (CeAD).

Common features

As a disease family, arterial dissections share common features, including shared genetic risk variants, and commonly perturbed molecular pathways. [2] This includes dysfunction of the TGF-β pathway, extracellular matrix pathways, cellular metabolism and vascular smooth muscle cell contractility. Variants in genes including Collagen genes COL1A1, COL1A2, COL3A1, COL4A1, COL5A2, as well as extracellular matrix genes FBN1, FBN2, LOX, MFAP5; TGF-β pathways genes LRP1, TGFBR2, TGFB2; cytoskeletal/contractile pathway genes and PHACTR1, MYLK, PRKG1, and TLN1; and vascular smooth muscle cell gene SLC2A10 have all been implicated in at least two types of arterial dissection. [2]

Related Research Articles

<span class="mw-page-title-main">Aorta</span> Largest artery in the human body

The aorta is the main and largest artery in the human body, originating from the left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at the aortic bifurcation into two smaller arteries. The aorta distributes oxygenated blood to all parts of the body through the systemic circulation.

<span class="mw-page-title-main">Artery</span> Blood vessels that carry blood away from the heart

An artery is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in the pulmonary circulation that carry blood to the lungs for oxygenation, and the umbilical arteries in the fetal circulation that carry deoxygenated blood to the placenta. It consists of a multi-layered artery wall wrapped into a tube-shaped channel.

<span class="mw-page-title-main">Circle of Willis</span> Circulatory anastomosis that supplies blood to the brain and surrounding structures

The circle of Willis is a circulatory anastomosis that supplies blood to the brain and surrounding structures in reptiles, birds and mammals, including humans. It is named after Thomas Willis (1621–1675), an English physician.

<span class="mw-page-title-main">Aortic dissection</span> Injury to the innermost layer of the aorta

Aortic dissection (AD) occurs when an injury to the innermost layer of the aorta allows blood to flow between the layers of the aortic wall, forcing the layers apart. In most cases, this is associated with a sudden onset of severe chest or back pain, often described as "tearing" in character. Vomiting, sweating, and lightheadedness may also occur. Damage to other organs may result from the decreased blood supply, such as stroke, lower extremity ischemia, or mesenteric ischemia. Aortic dissection can quickly lead to death from insufficient blood flow to the heart or complete rupture of the aorta.

<span class="mw-page-title-main">Subclavian artery</span> Major arteries of the upper thorax, below the clavicle

In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.

<span class="mw-page-title-main">Vascular surgery</span> Medical specialty of the blood/lymph vessels

Vascular surgery is a surgical subspecialty in which vascular diseases involving the arteries, veins, or lymphatic vessels, are managed by medical therapy, minimally-invasive catheter procedures and surgical reconstruction. The specialty evolved from general and cardiovascular surgery where it refined the management of just the vessels, no longer treating the heart or other organs. Modern vascular surgery includes open surgery techniques, endovascular techniques and medical management of vascular diseases - unlike the parent specialities. The vascular surgeon is trained in the diagnosis and management of diseases affecting all parts of the vascular system excluding the coronaries and intracranial vasculature. Vascular surgeons also are called to assist other physicians to carry out surgery near vessels, or to salvage vascular injuries that include hemorrhage control, dissection, occlusion or simply for safe exposure of vascular structures.

<span class="mw-page-title-main">Vasa vasorum</span> Network of small blood vessels

Vasa vasorum are small blood vessels that comprise a vascular network supplying the walls of large blood vessels, such as elastic arteries and large veins.

<span class="mw-page-title-main">Thoracic aorta</span> Part of the aorta located in the thorax

The thoracic aorta is a part of the aorta located in the thorax. It is a continuation of the aortic arch. It is located within the posterior mediastinal cavity, but frequently bulges into the left pleural cavity. The descending thoracic aorta begins at the lower border of the fourth thoracic vertebra and ends in front of the lower border of the twelfth thoracic vertebra, at the aortic hiatus in the diaphragm where it becomes the abdominal aorta.

<span class="mw-page-title-main">Aortic arch</span> Part of the aorta

The aortic arch, arch of the aorta, or transverse aortic arch is the part of the aorta between the ascending and descending aorta. The arch travels backward, so that it ultimately runs to the left of the trachea.

<span class="mw-page-title-main">Aortic arches</span>

The aortic arches or pharyngeal arch arteries are a series of six paired embryological vascular structures which give rise to the great arteries of the neck and head. They are ventral to the dorsal aorta and arise from the aortic sac.

<span class="mw-page-title-main">Subclavian steal syndrome</span> Medical condition

Subclavian steal syndrome (SSS), also called subclavian steal steno-occlusive disease, is a medical condition characterized by retrograde (reversed) blood flow in the vertebral artery or the internal thoracic artery. This reversal occurs due to proximal stenosis (narrowing) or occlusion of the subclavian artery.

<span class="mw-page-title-main">Vertebral artery dissection</span> Tear of the inner lining of the vertebral artery

Vertebral artery dissection (VAD) is a flap-like tear of the inner lining of the vertebral artery, which is located in the neck and supplies blood to the brain. After the tear, blood enters the arterial wall and forms a blood clot, thickening the artery wall and often impeding blood flow. The symptoms of vertebral artery dissection include head and neck pain and intermittent or permanent stroke symptoms such as difficulty speaking, impaired coordination, and visual loss. It is usually diagnosed with a contrast-enhanced CT or MRI scan.

Coronary artery anomalies are variations of the coronary circulation, affecting <1% of the general population. Symptoms include chest pain, shortness of breath and syncope, although cardiac arrest may be the first clinical presentation. Several varieties are identified, with a different potential to cause sudden cardiac death.

An elastic artery is an artery with many collagen and elastin filaments in the tunica media, which gives it the ability to stretch in response to each pulse. This elasticity also gives rise to the Windkessel effect, which helps to maintain a relatively constant pressure in the arteries despite the pulsating nature of the blood flow. Elastic arteries include the largest arteries in the body, those closest to the heart. They give rise to medium-sized vessels known as distributing arteries.

<span class="mw-page-title-main">Cervical artery dissection</span> Medical condition

Cervical artery dissection is dissection of one of the layers that compose the carotid and vertebral artery in the neck (cervix). They include:

The following outline is provided as an overview of and topical guide to cardiology, the branch of medicine dealing with disorders of the human heart. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. Physicians who specialize in cardiology are called cardiologists.

<span class="mw-page-title-main">Familial aortic dissection</span> Medical condition

Familial aortic dissection or FAD refers to the splitting of the wall of the aorta in either the arch, ascending or descending portions. FAD is thought to be passed down as an autosomal dominant disease and once inherited will result in dissection of the aorta, and dissecting aneurysm of the aorta, or rarely aortic or arterial dilation at a young age. Dissection refers to the actual tearing open of the aorta. However, the exact gene(s) involved has not yet been identified. It can occur in the absence of clinical features of Marfan syndrome and of systemic hypertension. Over time this weakness, along with systolic pressure, results in a tear in the aortic intima layer thus allowing blood to enter between the layers of tissue and cause further tearing. Eventually complete rupture of the aorta occurs and the pleural cavity fills with blood. Warning signs include chest pain, ischemia, and hemorrhaging in the chest cavity. This condition, unless found and treated early, usually results in death. Immediate surgery is the best treatment in most cases. FAD is not to be confused with PAU and IMH, both of which present in ways similar to that of familial aortic dissection.

<span class="mw-page-title-main">Spontaneous coronary artery dissection</span> Uncommon cause of heart attacks mostly affecting younger, healthy women

Spontaneous coronary artery dissection (SCAD) is an uncommon but potentially lethal condition in which one of the coronary arteries that supply the heart, spontaneously develops a blood collection, or hematoma, within the artery wall due to a tear in the wall. SCAD is one of the arterial dissections that can occur.

References

  1. Salgado OJ, Chacón RE, Alcalá A, Alvarez G (2005). "Vein wall dissection: a rare puncture-related complication of brachiocephalic fistula. Gray-scale and color Doppler sonographic findings". J Clin Ultrasound. 33 (9): 464–7. doi:10.1002/jcu.20171. PMID   16281272. S2CID   20589311.
  2. 1 2 3 Bax M, Romanov V, Junday K, Giannoulatou E, Martinac B, Kovacic JC, Liu R, Iismaa SE, Graham RM (2022). "Arterial dissections: Common features and new perspectives". Frontiers in Cardiovascular Medicine. 9. doi: 10.3389/fcvm.2022.1055862 . PMC   9763901 . PMID   36561772.
  3. Khattar, R. S.; Fox, D. J.; Alty, J. E.; Arora, A. (1 February 2005). "Pulmonary artery dissection: an emerging cardiovascular complication in surviving patients with chronic pulmonary hypertension". Heart. 91 (2): 142–145. doi:10.1136/hrt.2004.045799. PMC   1768672 . PMID   15657218 . Retrieved 13 February 2023.