Collateral vessels develop to help drain the affected area.

After 24 weeks an increased number of collateral vessels and improved recovery in blood perfusion was observed.

Many people, however, do not form collateral vessels, or do not form enough.

This is because of collateral vessels.

But Mr. Ratuszny seemed to lack those collateral vessels.

These new collateral vessels will increase blood flow and tissue perfusion, thereby effectively treating ischemia.

Leaking microvascular abnormalities may be treated directly, but prominent collateral vessels should be avoided.

These people form 10 to 50 extra blood vessels, called collateral vessels, that wind their way past the blockage and provide a new pathway for blood.

Repeat abdominal ultrasonography was normal with spleen length 10 cm and no evidence of ascites, collateral vessels, or varices.

The collateral vessels "are sort of like a heat-seeking missile," as they migrate to and around the blockage, Dr. Isner said.

Presence of corkscrew collateral vessels in vasa vasorum is a hallmark of Buerger's disease and distinguishes it from Raynaud's phenomenon.

Dr. Isner and his colleagues propose to provide a gene for vegf molecules that will allow formation of collateral vessels in patients who do not make them on their own.

Ultrasound may show obliteration of hepatic veins, thrombosis or stenosis, spiderweb vessels, large collateral vessels, or a hyperechoic cord replacing a normal vein.

It is the first time that a drug has led to growth of new coronary blood vessels by mimicking the way collateral vessels naturally develop in some people with blocked arteries.

A collateral circulation develops around the blocked vessels to compensate for the blockage, but the collateral vessels are small, weak, and prone to hemorrhage, aneurysm and thrombosis.

Using PTCA, Rentrop demonstrated that collateral vessel filling jumps dramatically during coronary occlusion by balloon inflation-within ninety seconds of total occlusion.

This leads to attraction and activation of monocytes and T-cells into the adventitial space (peripheral collateral vessels) or attachment of these cells to the endothelium (coronary collaterals).

This is supported by the fact that the extent of hypoxic induction of VEGF-A in monocytes correlates strongly with the presence of collateral vessels in patients [ 29].

It is possible that genetic variability may also play a significant role in an individual's ability to generate collateral vessels in response to ischemia, as well as their capacity to respond to an exogenous angiogenic agent.

Naked plasmid DNA injected directly into the skeletal muscle in a later study, using the same hind limb ischemia model, also yielded increased collateral vessels, as determined by angiography and improved perfusion [ 7].

It is a potent, physiological process that underlies the natural manner in which our bodies respond to a diminution of blood supply to vital organs, namely the production of new collateral vessels to overcome the ischemic insult.

The functional significance of the coronary collateral vessels is a matter of continuing experimental investigation although their existence has been known for over three centuries and been documented repeatedly in man and beast over the past seven decades.

Collateral vessel development, as measured by blood pressure, angiography, and vessel density, was significantly reduced in old (4-5 years old) versus young (6-8 months old) animals [ 27], in a rabbit model of hind limb ischemia.

In one early study using recombinant protein, a single intra-arterial injection of 500-1000 μg VEGF165 into rabbits with severe experimental hind limb ischemia increased collateral vessels, as detected by angiography and histological analysis [ 6].

The superior epigastric arteries, inferior epigastric arteries, internal thoracic arteries and left subclavian artery and right subclavian artery / brachiocephalic are collateral vessels to the thoracic aorta and abdominal aorta.