In
medicineMedicine is the art and science of healing. It encompasses a range of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
(
gastroenterologyGastroenterology is the branch of medicine whereby the digestive system and its disorders are studied. Etymologically, the name is a combination of three Ancient Greek words gastros , enteron , and logos ....
),
angiodysplasia is a small
vascularThe blood vessels are the part of the circulatory system that transport blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart, the capillaries, which enable the actual exchange of water and chemicals between the blood and...
malformation of the gut. It is a common cause of otherwise unexplained gastrointestinal bleeding and
anemiaAnemia is a decrease in normal number of red blood cells or less than the normal quantity of hemoglobin in the blood...
. Lesions are often multiple, and frequently involve the
cecumThe cecum or caecum is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine...
or
ascending colonThe ascending colon is smaller in caliber than the cecum, with which it is contiguous.It passes upward, from its commencement at the cecum, opposite the colic valve, to the under surface of the right lobe of the liver, on the right of the gall-bladder, where it is lodged in a shallow depression,...
, although they can occur at other places. Treatment may be with endoscopic interventions, medication, or occasionally surgery.
Although some cases present with black, tarry stool (
melenaIn medicine, melena or melaena refers to the black, "tarry" feces that are associated with gastrointestinal hemorrhage. The black color is caused by oxidation of the iron in hemoglobin during its passage through the ileum and colon.-Melena vs...
), the blood loss can be subtle, with the anemia symptoms predominating.
In
medicineMedicine is the art and science of healing. It encompasses a range of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
(
gastroenterologyGastroenterology is the branch of medicine whereby the digestive system and its disorders are studied. Etymologically, the name is a combination of three Ancient Greek words gastros , enteron , and logos ....
),
angiodysplasia is a small
vascularThe blood vessels are the part of the circulatory system that transport blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart, the capillaries, which enable the actual exchange of water and chemicals between the blood and...
malformation of the gut. It is a common cause of otherwise unexplained gastrointestinal bleeding and
anemiaAnemia is a decrease in normal number of red blood cells or less than the normal quantity of hemoglobin in the blood...
. Lesions are often multiple, and frequently involve the
cecumThe cecum or caecum is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine...
or
ascending colonThe ascending colon is smaller in caliber than the cecum, with which it is contiguous.It passes upward, from its commencement at the cecum, opposite the colic valve, to the under surface of the right lobe of the liver, on the right of the gall-bladder, where it is lodged in a shallow depression,...
, although they can occur at other places. Treatment may be with endoscopic interventions, medication, or occasionally surgery.
Signs and symptoms
Although some cases present with black, tarry stool (
melenaIn medicine, melena or melaena refers to the black, "tarry" feces that are associated with gastrointestinal hemorrhage. The black color is caused by oxidation of the iron in hemoglobin during its passage through the ileum and colon.-Melena vs...
), the blood loss can be subtle, with the anemia symptoms predominating.
Fecal occult bloodFaecal occult blood is a term for blood present in the faeces that is not visibly apparent. In medicine, a faecal occult blood test is a check for hidden blood in the stool . Conventional faecal occult blood tests look for heme...
testing is positive when bleeding is active. If bleeding is intermittent the test may be negative at times.
Diagnosis
Diagnosis of angiodysplasia is often accomplished with
endoscopyEndoscopy means looking inside and typically refers to looking inside the body for medical reasons using an instrument called an endoscope...
, either
colonoscopyColonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus. It may provide a visual diagnosis Colonoscopy is the endoscopic examination of the large colon and the distal...
or
esophagogastroduodenoscopyIn medicine , esophagogastroduodenoscopy is a diagnostic endoscopic procedure that visualizes the upper part of the gastrointestinal tract up to the duodenum...
(EGD). Although the lesions can be notoriously hard to find, the patient usually is diagnosed by endoscopy. A new technique, pill enteroscopy, has been a major advance in diagnosis, especially in the small bowel which is difficult to reach with traditional endoscopy. With this technique a pill that contains a video camera and radio transmitter is swallowed, and pictures of the small intestine are sent to a receiver worn by the patient.
Angiodysplasiae in the small bowel can also be diagnosed and treated with
double-balloon enteroscopyDouble-balloon enteroscopy, also known as push-and-pull enteroscopy is an endoscopic technique for visualization of the small bowel. It was developed by Hironori Yamamoto in 2001. It is novel in the field of diagnostic gastroenterology as it is the first endoscopic technique that allows for the...
, a technique involving a long endoscopic camera and overtube, both fitted with balloons, that allow the bowel to be accordioned over the camera.
In cases with negative endoscopic findings and high clinical suspicion, selective angiography of the mesenteric arteries is sometimes necessary, but this allows for interventions at time of the procedure. An alternative is scintigraphy with
red blood cellRed blood cells are the most common type of blood cell and the vertebrate body's principal means of delivering oxygen to the body tissues via the blood. They take up oxygen in the lungs or gills and release it while squeezing through the body's capillaries. The cells are filled with hemoglobin, a...
s labeled with a radioactive marker; this shows the site of the bleeding on a
gamma cameraA gamma camera is a device used to image gamma radiation emitting radioisotopes, a technique known as scintigraphy. The applications of scintigraphy include early drug development and nuclear medical imaging to view and analyse images of the human body or the distribution of medically injected,...
but tends to be unhelpful unless the bleeding is continuous and significant.
Pathophysiology
Histologically, it resembles
telangiectasiaTelangiectasias are small derogative blood vessels near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. They can develop anywhere on the body but are commonly seen on the face around the nose, cheeks, and chin...
. Development is related to age and strain on the bowel wall, which is thought to influence the caliber change and proliferation of the vascular tissue.
Although angiodysplasia is probably quite common, the risk of
bleedingBleeding, technically known as hemorrhaging or haemorrhaging is the loss of blood or blood escape from the circulatory system...
is increased in disorders of
coagulationCoagulation is a complex process by which blood forms clots. It is an important part of hemostasis , wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel...
. A classic association is
Heyde's syndromeHeyde's syndrome is a syndrome of aortic valve stenosis associated with gastrointestinal bleeding from colonic angiodysplasia. It is named after Dr. Edward C. Heyde, who first described the association in 1958...
(coincidence of
aortic valve stenosisAortic valve stenosis is a valvular heart disease caused by the incomplete opening of the aortic valve.The aortic valve controls the direction of blood flow from the left ventricle to the aorta. When in good working order, the aortic valve does not impede the flow of blood between these two spaces...
and bleeding from angiodysplasia).
In this disorder,
von Willebrand factorVon Willebrand factor is a blood glycoprotein involved in hemostasis. It is deficient or defective in von Willebrand disease and is involved in a large number of other diseases, including thrombotic thrombocytopenic purpura, Heyde's syndrome, and possibly hemolytic-uremic syndrome.- Synthesis :vWF...
(vWF) is proteolysed due to high
shear stressA shear stress, denoted , is defined as a stress which is applied parallel or tangential to a face of a material, as opposed to a normal stress which is applied perpendicularly.-General shear stress:...
in the highly turbulent blood flow around the aortic valve. vWF is most active in vascular beds with high shear stress, including angiodysplasias, and deficiency of vWF increases the bleeding risk from such lesions.
Warkentin
et al. argue that apart from
aortic valve stenosisAortic valve stenosis is a valvular heart disease caused by the incomplete opening of the aortic valve.The aortic valve controls the direction of blood flow from the left ventricle to the aorta. When in good working order, the aortic valve does not impede the flow of blood between these two spaces...
, some other conditions that feature high shear stress might also increase the risk of bleeding from angiodysplasia.
Therapy
If the anemia is severe,
blood transfusionBlood transfusion is the process of transferring blood or blood-based products from one person into the circulatory system of another. Blood transfusions can be life-saving in some situations, such as massive blood loss due to trauma, or can be used to replace blood lost during surgery...
is required before any other intervention is considered.
EndoscopicEndoscopy means looking inside and typically refers to looking inside the body for medical reasons using an instrument called an endoscope...
treatment is an initial possibility, where cautery or
argon plasma coagulationArgon plasma coagulation or APC is a medical endoscopic procedure used primarily to control bleeding from certain lesions in the gastrointestinal tract, and also sometimes to debulk tumours in the case of patients for whom surgery is not recommended...
(APC) laser treatment is applied through the endoscope.
ResectionResection can mean:*Segmental resection the partial or complete removal of an organ or other bodily structure. A doctor may say that a cancer is resectable.*Resection , a means of establishing a location...
of the affected part of the bowel may be needed. However, the lesions may be widespread, making such treatment impractical. Embolisation through angiography is occasionally contemplated with severely bleeding lesions that cannot be visualised on colonoscopy.
If the bleeding is from multiple or inaccessible sites, systemic therapy with
medicationA pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
may be necessary. First-line options include the
antifibrinolyticAntifibrinolytics, such as aminocaproic acid and tranexamic acid are used as inhibitors of fibrinolysis. These lysine-like drugs interfere with the formation of the fibrinolytic enzyme plasmin from its precursor plasminogen by plasminogen activators which takes place mainly in lysine rich areas...
s
tranexamic acidTranexamic acid is often prescribed for excessive bleeding. It is an antifibrinolytic that competitively inhibits the activation of plasminogen to plasmin, a molecule responsible for the degradation of fibrin...
or
aminocaproic acidAminocaproic acid is a derivative and analogue of the amino acid lysine, which makes it an effective inhibitor for enzymes that bind that particular residue. Such enzymes include proteolytic enzymes like plasmin, the enzyme responsible for fibrinolysis...
. Estrogens can be used to stop bleeding from angiodysplasia. Estrogens cause mild hypercoaguability of the blood. Estrogen side effects can be dangerous and unpleasant in both sexes. Changes in voice and
breast swellingGynecomastia, , is the development of abnormally large mammary glands in males resulting in breast enlargement. The term comes from the Greek γυνή gyne meaning "woman" and μαστός mastos meaning "breast"...
is bothersome in men, but older women often report improvement of
libidoLibido in its common usage means sexual desire; however, more technical definitions, such as those found in the work of Carl Jung, are more general, referring to libido as the free creative—or psychic—energy an individual has to put toward personal development or individuation.- History of the...
and
perimenopausalMenopause is the time in a woman’s life when menstruation ends. It is part of a biological process that begins, for most women, in their mid-fifties. During this time, the ovaries gradually produce lower levels of natural sex hormones—estrogen and progesterone...
symptoms. (The worries about
hormone replacement therapyHormone replacement therapy may refer to:*Hormone replacement therapy *Hormone replacement therapy *Hormone replacement therapy *Androgen replacement therapy -See also:...
/HRT, however, apply here as well.)
In difficult cases, there have been positive reports about
octreotideOctreotide is an octapeptide that mimics natural somatostatin pharmacologically, though it is a more potent inhibitor of growth hormone, glucagon, and insulin than the natural hormone...
and thalidomide.
In severe cases or cases not responsive to either endoscopic or medical treatment,
surgerySurgery is a medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, to help improve bodily function or appearance, or sometimes for some other reason...
may be necessary to arrest the bleeding.