intestinal bypass


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bypass

 [bi´pas″]
an auxiliary flow; a shunt; a surgically created pathway circumventing the normal anatomical pathway, such as in an artery or the intestine.
Bypass. Single artery bypass of an occluded right coronary artery. From Dorland's, 2000.
aortocoronary bypass coronary artery bypass.
aortofemoral bypass insertion of a vascular prosthesis from the aorta to the femoral artery to bypass atherosclerotic occlusions in the aorta and the iliac artery.
aortoiliac bypass insertion of a vascular prosthesis from the abdominal aorta to the femoral artery to bypass intervening atherosclerotic segments.
axillofemoral bypass insertion of a vascular prosthesis or section of saphenous vein from the axillary artery to the ipsilateral femoral artery to relieve lower limb ischemia in patients in whom normal anatomic placement of a graft is contraindicated, as by abdominal infection or aortic aneurysm.
axillopopliteal bypass insertion of a vascular prosthesis from the axillary artery to the popliteal artery to relieve lower limb ischemia in patients in whom the femoral artery is unsuitable for axillofemoral bypass.
cardiopulmonary bypass diversion of the flow of blood from the entrance to the right atrium directly to the aorta, usually via a pump oxygenator, avoiding both the heart and the lungs; a form of extracorporeal circulation used in heart surgery.
coronary bypass (coronary artery bypass) a section of saphenous vein or other conduit grafted between the aorta and a coronary artery distal to an obstructive lesion in the latter; called also aortocoronary bypass.
extra-anatomic bypass an arterial bypass that does not follow the normal anatomic pathway, such as an axillofemoral bypass.
extracranial/intracranial bypass anastomosis of the superficial temporal artery to the middle cerebral artery to preserve function or prevent stroke or death in patients with stenosis of the internal carotid or middle cerebral artery.
femorofemoral bypass insertion of a vascular prosthesis between the femoral arteries to bypass an occluded or injured iliac artery.
femoropopliteal bypass insertion of a vascular prosthesis from the femoral to the popliteal artery to bypass occluded segments.
gastric bypass see gastric bypass.
hepatorenal bypass insertion of a vascular prosthesis between the common hepatic artery and the renal artery, serving as a passage around an occluded segment of renal artery.
intestinal bypass (jejunoileal bypass) see intestinal bypass.
left heart bypass diversion of the flow of blood from the pulmonary veins directly to the aorta, avoiding the left atrium and the left ventricle.
partial bypass the deviation of only a portion of the blood flowing through an artery.
partial ileal bypass anastomosis of the proximal end of the transected ileum to the cecum, the bypass of the portion of the small intestine resulting in decreased intestinal absorption of and increased fecal excretion of cholesterol; sometimes used in treatment of hyperlipidemia.
right heart bypass diversion of the flow of blood from the entrance of the right atrium directly to the pulmonary arteries, avoiding the right atrium and right ventricles.

intestinal

 [in-tes´tĭ-nal]
pertaining to the intestine.
intestinal bypass a surgical procedure in which all but a short section of the proximal jejunum and terminal ileum is bypassed in order to bring about malabsorption of digested food. The procedure is done for the purpose of correcting obesity. Patients having this type of surgery must be meticulously managed so that severe nutritional cirrhosis and serious loss of water and electrolytes are avoided. Called also jejunoileal bypass and jejunoileal shunt.
intestinal flu a popular term for what may be any of several disorders of the stomach and intestinal tract. The symptoms are nausea, diarrhea, abdominal cramps, and fever. During the acute stage all foods should be avoided. Carbonated soft drinks such as ginger ale or cola can be taken in moderation to relieve the nausea. When the symptoms subside, the diet should at first be confined to liquids and soft, bland foods. Milk and dairy products, butter and fats generally, fruits, and greens should be avoided completely until the patient is free of all symptoms.
intestinal obstruction any hindrance to the passage of the intestinal contents. Causes may be mechanical or neural or both. Some of the more common mechanical causes are hernia, adhesions of the peritoneum, volvulus, intussusception, malignant or benign tumor, congenital defect, and local inflammation, as in diverticulitis. Failure of peristalsis (adynamic ileus) is frequently associated with peritonitis; it also may occur with gallstones, uremia, heavy metal poisoning, infection, and spinal injury.
Symptoms. The most characteristic symptoms are abdominal pain, vomiting, and distention. The symptoms may be mild at first and in its early stages the condition can be confused with less serious disorders of the intestinal tract. Under no circumstances should the patient be given a cathartic or other laxative, because that will aggravate the situation. If the obstruction continues the patient suffers from dehydration and shock because of inadequate absorption of fluids, electrolytes, and nutrients from the intestinal tract. If the bowel becomes strangulated and circulation to the bowel wall is obstructed, the patient shows signs of peritonitis with extreme tenderness and rigidity of the abdomen.
Diagnosis. The diagnosis of obstruction can usually, but not always, be made from plain abdominal radiographs. If there is a question, a gastrointestinal series with barium will usually resolve the issue quickly.
Treatment. The basic steps of treatment are decompression of the intestine, replacement of fluids and electrolytes, and removal of the cause of the obstruction. Decompression is accomplished by intubation with a special tube (usually the miller-abbott tube) designed to reach past the pyloric sphincter and into the intestine. Constant suction is then applied to remove accumulations of gas and liquids. Fluids, sodium chloride, and glucose are administered intravenously at a specific rate as prescribed. Transfusions of whole blood plasma may be given as necessary to restore normal blood values.

Surgical removal of the cause of obstruction is necessary in cases of complete obstruction. If there is no evidence of strangulation of the bowel, the surgeon may choose to postpone surgery until dehydration and shock have been overcome and a normal electrolyte balance is restored. The type of surgical procedure performed depends on the cause of the obstruction and whether or not the intestine is gangrenous. In some cases a colostomy may be necessary along with removal of the damaged portion of the bowel. A surgical incision into the cecum with insertion of a drainage tube (cecostomy) may be done when intestinal intubation is not successful in relieving distention.
Patient Care. Assessment of the patient with intestinal obstruction includes noting the location and character of abdominal pain, degree of distention, character of the bowel sounds, and occurrence or absence of bowel movements or passing of flatus. Should defecation occur, a specimen is saved for examination and laboratory analysis. If there is vomiting, the amount and special characteristics of the vomitus should be noted and recorded. In severe cases of obstruction of the small bowel the vomitus may contain fecal material because of the reversal of peristalsis and forcing of the intestinal contents backward into the stomach. Foods and fluids by mouth are restricted. Frequent mouth care is necessary to relieve the dryness and foul taste that accompanies intestinal obstruction and vomiting. Urinary output is measured and recorded because of the possibility of decreased urinary output related to dehydration.
Preoperative Care. If conservative measures fail to relieve the obstruction, or if the bowel has become strangulated, surgery is indicated. Suction siphonage, once initiated, is continued and the intestinal tube is left in place when the patient goes to the operating room.
Postoperative Care. Routine postoperative care of the patient with abdominal surgery is indicated. Specific measures depend on the type of surgical procedure done. Suction siphonage is usually continued until peristalsis resumes. Results of the assessment of bowel sounds and the passing of flatus or feces should be noted on the patient's chart because they indicate a return of normal peristaltic movements of the bowel. In some cases a cecostomy tube or rectal tube is inserted during surgery; the tube is attached to a drainage system and the amount and type of material collected in the system are recorded. If there is evidence that the tube has become obstructed the surgeon should be notified. The skin around the site of insertion of a cecostomy tube should be protected with a skin barrier. The area must be washed frequently to avoid erosion of the skin by intestinal contents leaking around the tube. (See colostomy for patient care after that procedure.)
intestinal tract the small and large intestines in continuity; this long, coiled tube is the part of the digestive system where most of the digestion of food takes place. (See color plates.) The small intestine has three parts: the duodenum (connected to the stomach), the jejunum, and the ileum. The small intestine is small in diameter but very long (about 6.1 m). The large intestine, which starts just below the ileum, is about 1.5 m long. It is made up of the cecum (to which the appendix is attached), the colon (comprising the ascending, transverse, and descending colon and the sigmoid), and the rectum.

The digestion of food is completed in the small intestine. The digested food is absorbed through the walls of the small intestine into the blood. Indigestible parts of the food pass into the large intestine. Here the liquid from the wastes is gradually absorbed back into the body through the intestinal walls. The waste itself is formed into fairly solid feces and pushed down into the rectum for evacuation.

Among the disorders of the intestinal tract are the disturbances of function, such as diarrhea, constipation, and irritable bowel syndrome; the organic diseases, ulcerative colitis, appendicitis, and ileitis; and communicable diseases, such as dysentery. Irritable bowel syndrome is characterized by constipation, sometimes alternating with diarrhea. Ulcerative colitis is a disorder in which ulcers may appear in the wall of the large intestine. Ileitis is a disorder of the ileum, or lower portion of the small intestine. A symptom of both is diarrhea. Dysentery, which is characterized by diarrhea, is the result of infection by bacteria, viruses, or various parasites.

intestinal bypass

Etymology: L, intestinum + AS, bi + Fr, passer + Gk, cheirourgos
a surgical procedure to shorten the digestive tract. It is performed so that less intestinal surface will be available to absorb nutrients from the digested food passing through, as in morbid obesity, or to bypass a blocked or diseased portion of the intestine. The technique usually involves anastomosing the jejunum to the ileum. See also ileal bypass.
References in periodicals archive ?
A third series of articles followed 118 massively obese women undergoing intestinal bypass and their husbands.
96), given our experience interviewing and assessing some 200 male and female intestinal bypass patients (R.
Changes in body image and other psychological factors after intestinal bypass surgery for massive obesity.
Psychosocial effects of intestinal bypass surgery for severe obesity.
Psychological effects of intestinal bypass surgery.
The adjustable gastric banding procedure, which does not involve an intestinal bypass, is getting more attention as a possible "best" operation for adolescents--even though long-term results in adults have not been compared with those of gastric bypass surgery--because it eliminates concerns about nutritional and mineral malabsorption, Dr.
Secondary causes of low bone mineral density (BMD) include endocrinopathies (hypercalciuria, hypogonadism, hyper-parathyroidism, and Cushing's syndrome), some GI disorders (gastrectomy, inflammatory bowel disease, celiac disease, intestinal bypass surgery, primary biliary cirrhosis, and pancreatic insufficiency), genetic disorders (Ehlers-Danlos syndrome, Marfan syndrome, and homocystinuria), and eating disorders (anorexia nervosa, bulimia nervosa, and female athlete triad).