A Cimino fistula, also Cimino-Brescia fistula, surgically created arteriovenous fistula and (less precisely) arteriovenous fistula (often

abbreviated An abbreviation (from Latin ''brevis'', meaning ''short'') is a shortened form of a word or phrase, by any method. It may consist of a group of letters or words taken from the full version of the word or phrase; for example, the word ''abbrevia ...

AV fistula or AVF), is a type of vascular access for

hemodialysis Hemodialysis, also spelled haemodialysis, or simply dialysis, is a process of purifying the blood of a person whose kidneys are not working normally. This type of dialysis achieves the extracorporeal removal of waste products such as creatinin ...

. It is typically a surgically created connection between an

artery An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pul ...

and a

vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...

in the arm, although there have been acquired arteriovenous fistulas which do not in fact demonstrate connection to an artery. Dialysehunt

Structure

The radiocephalic arteriovenous fistula (RC-AVF) is a shortcut created between cephalic vein and radial artery at the wrist. It is the recommended first choice for hemodialysis access. However, after a period of usage, failures can occur. Possible causes for failure are stenosis and thrombosis especially in diabetics and those with low blood flow such as due to narrow vessels, arteriosclerosis and advanced age. Reported patency of fistulae after 1 year is about 60%, when primary failures were included. Juxa-anastomotic site (venous segment that is between 2 and 5 cm distal to the anastomotic site) is the most common site of stenosis. One of the reasons affecting the rate of stenosis could be the anastomotic angle. In

computational fluid dynamics Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate th ...

study, the ideal anastomotic angle should be less than 30 degrees to ensure

laminar flow In fluid dynamics, laminar flow is characterized by fluid particles following smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. At low velocities, the fluid tends to flow without lateral mi ...

of the blood, thus prolong the

endothelial cell The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel ...

survival, and prevent smooth muscle proliferation within vessel wall, and clogging the vessel. However, in another study using angiographic images of the juxta-anastomotic sites, the ideal anastomotic angle of less than 46.5 degrees was obtained. Surgically created AV fistulas work effectively because they: * Have high

volume flow rate In physics and engineering, in particular fluid dynamics, the volumetric flow rate (also known as volume flow rate, or volume velocity) is the volume of fluid which passes per unit time; usually it is represented by the symbol (sometimes ). I ...

s (as blood takes the

path of least resistance The path of least resistance is the physical or metaphorical pathway that provides the least resistance to forward motion by a given object or entity, among a set of alternative paths. The concept is often used to describe why an object or entit ...

; it prefers the (low resistance) AV fistula over traversing (high resistance) capillary beds). * Use native blood vessels, which, when compared to synthetic grafts, are less likely to develop stenoses and fail.

History

The procedure was invented by doctors James Cimino and M. J. Brescia at the

Bronx Veterans Administration Hospital The James J. Peters VA Medical Center, (also known as the Bronx Veterans Hospital), is a US Department of Veterans Affairs hospital complex located at 130 West Kingsbridge Road in West Fordham, Bronx, New York City. The hospital is the headquar ...

in 1966. Before the Cimino fistula was invented, access was through a Scribner shunt, which consisted of a

Teflon Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemou ...

tube with a needle at each end. Between treatments, the needles were left in place and the tube allowed blood flow to reduce clotting. But Scribner shunts lasted only a few days to weeks. Frustrated by this limitation, James E. Cimino recalled his days as a

phlebotomist Phlebotomy is the process of making a puncture in a vein, usually in the arm, with a cannula for the purpose of drawing blood. The procedure itself is known as a venipuncture, which is also used for intravenous therapy. A person who performs a ph ...

(blood drawer) at

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

Bellevue Hospital Bellevue Hospital (officially NYC Health + Hospitals/Bellevue and formerly known as Bellevue Hospital Center) is a hospital in New York City and the oldest public hospital in the United States. One of the largest hospitals in the United States b ...

in the 1950s when

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veteran A veteran () is a person who has significant experience (and is usually adept and esteemed) and expertise in a particular occupation or field. A military veteran is a person who is no longer serving in a military. A military veteran that has ...

s showed up with

fistulas A fistula (plural: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") in anatomy is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow org ...

caused by trauma. Cimino recognized that these fistulas did not cause the patients harm and were easy places to get repeated blood samples. He convinced surgeon Kenneth Appell to create some in patients with

chronic kidney failure Chronic kidney disease (CKD) is a type of kidney disease in which a gradual loss of kidney function occurs over a period of months to years. Initially generally no symptoms are seen, but later symptoms may include leg swelling, feeling tired, vom ...

and the result was a complete success. Scribner shunts were quickly replaced with Cimino fistulas, and they remain the most effective, longest-lasting method for long-term access to patients' blood for hemodialysis today.

References

{{Reflist

External links

A Milestone in Hemodialysis: James E. Cimino, MD, and the Development of the AV Fistula
Vascular surgery Renal dialysis