Anastomosis

An anastomosis (/əˌnæstəˈmoʊsɪs/, pl.: anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal (such as the foramen ovale in a fetus' heart) or abnormal (such as the patent foramen ovale in an adult's heart); it may be acquired (such as an arteriovenous fistula) or innate (such as the arteriovenous shunt of a metarteriole); and it may be natural (such as the aforementioned examples) or artificial (such as a surgical anastomosis). The reestablishment of an anastomosis that had become blocked is called a reanastomosis. Anastomoses that are abnormal, whether congenital or acquired, are often called fistulas.

The term is used in medicine, biology, mycology, geology, and geography.

Anastomosis: medical or Modern Latin, from Greek ἀναστόμωσις, anastomosis, "outlet, opening", Greek ana- "up, on, upon", stoma "mouth", "to furnish with a mouth". Thus the -stom- syllable is cognate with that of stoma in botany or stoma in medicine.

An anastomosis is the connection of two normally divergent structures. It refers to connections between blood vessels or between other tubular structures such as loops of intestine.

In circulatory anastomoses, many arteries naturally anastomose with each other; for example, the inferior epigastric artery and superior epigastric artery, or the anterior and/or posterior communicating arteries in the Circle of Willis in the brain. The circulatory anastomosis is further divided into arterial and venous anastomosis. Arterial anastomosis includes actual arterial anastomosis (e.g., palmar arch, plantar arch) and potential arterial anastomosis (e.g. coronary arteries and cortical branch of cerebral arteries). Anastomoses also form alternative routes around capillary beds in areas that do not need a large blood supply, thus helping regulate systemic blood flow.^{[citation needed]}

Surgical anastomosis occurs when segments of intestine, blood vessel, or any other structure are connected together surgically (anastomosed). Examples include arterial anastomosis in bypass surgery, intestinal anastomosis after a piece of intestine has been resected, Roux-en-Y anastomosis and ureteroureterostomy. Surgical anastomosis techniques include linear stapled anastomosis, hand sewn anastomosis, end-to-end anastomosis (EEA). Anastomosis can be performed by hand or with an anastomosis assist device. Studies have been performed comparing various anastomosis approaches taking into account surgical "time and cost, postoperative anastomotic bleeding, leakage, and stricture".

Anastomotic leakage in colorectal cancer surgery

Failure of an intestinal anastomosis with leakage of intestinal content in to the abdominal cavity is one of the most severe complications after bowel surgery. The severity of anastomotic leakage varies ranging from mild with minimal impact on the patient to severe and potentially fatal, with negative impact on both short- and long-term outcomes. The incidence has not changed in recent decades, despite improvement in surgical techniques, prehabilitation and perioperative care. Anastomotic leakage after rectal cancer surgery is higher and documented to occur in 9-11%, after colon resection the incidence of leakage is lower and about 6%. Systemic factors contributing to anastomotic failure include sepsis, anemia, diabetes mellitus, previous irradiation, malnutrition, steroid use, smoking, heavy alcohol consumption, obesity and certain disease conditions like Chron's disease.