Adhesions

Definition

Adhesions are fibrous bands of scar tissue that form between internal organs and tissues, joining them together abnormally.

Description

Adhesions are made up of blood vessels and fibroblasts—connective tissue cells. They form as a normal part of the body's healing process and help to limit the spread of infection. However when adhesions cause the wrong tissues to grow into each other, many different complex inflammatory disorders can arise. Worldwide millions of people suffer pain and dysfunction due to adhesion disease.

Depending on their location, the most common types of adhesions may called:

• abdominal adhesions
• intestinal adhesions
• intraperitoneal adhesions
• pelvic adhesions
• intrauterine adhesions or Asherman's syndrome.

Adhesions can form between various tissues in the body including:

• loops of the intestines
• the intestines and other abdominal organs or the abdominal wall
• abdominal organs such as the liver or bladder and the abdominal wall
• tissues of the uterus.

Although adhesions can be congenital (present at birth) or result from inflammation, injury, or infection, the vast majority of adhesions form following surgery. Adhesions are a major complication of many common surgical procedures and may occur in 55% to more than 90% of patients, depending on the type of surgery.

KEY TERMS

Asherman's syndrome— The cessation of menstruation and/or infertility caused by intrauterine adhesions.

Computed axial tomography; CT or CAT scan— A computer reconstruction of scanned x rays used to diagnose intestinal obstructions.

Endometriosis— A condition in which the endometrial tissue that lines the uterus begins to invade other parts of the body.

Endoscope— A device with a light that is used to look into a body cavity or organ.

Fibroblast— A connective-tissue cell.

Glaucoma— A group of eye diseases characterized by increased pressure within the eye that can damage the optic nerve and cause gradual loss of vision.

Hysteroscopy— A procedure in which an endoscope is inserted through the cervix to view the cervix and uterus.

Hysterosalpingography; HSG— X raying of the uterus and fallopian tubes following the injection of a contrast dye.

Irido corneal endothelial syndrome; ICE— A type of glaucoma in which cells from the back of the cornea spread over the surface of the iris and tissue that drains the eye, forming adhesions that bind the iris to the cornea.

Laparoscopic surgery; keyhole surgery— Surgery that utilizes a laparoscope with a video camera and surgical instruments inserted through small incisions.

Laparoscopy— A procedure that utilizes an endoscope to view contents of the abdominal cavity.

Pelvic inflammatory disease; PID— Inflammation of the female reproductive organs and associated structures.

Peritoneum— The membrane lining the walls of the abdominal and pelvic cavities and enclosing their organs.

Small bowel obstruction; SBO— An obstruction of the small intestine that prevents the free passage of material; sometimes caused by postoperative adhesions.

All abdominal surgeries carry the risk of adhesion formation. Abdominal adhesions are rare in people who have not had abdominal surgery and very common in people who have had multiple abdominal surgeries. Adhesions are more common following procedures involving the intestines, colon, appendix, or uterus. They are less common following surgeries involving the stomach, gall bladder, or pancreas. Although most abdominal adhesions do not cause problems, they can be painful when stretched or pulled because the scar tissue is not elastic.

Postoperative intestinal adhesions are a major cause of intestinal or small bowel obstruction (SBO). In a small number of people the scar tissue pulls sections of the small or large intestines out of place and partially or completely blocks the passage of food and fluids. Thus SBOs can result from abdominal surgery and also are one of the most common reasons for abdominal surgery. Although intestinal obstruction is fatal in about 5% of patients, the mortality rate associated with SBO has decreased dramatically over the past century.

Intrauterine adhesions are relatively common in women and the majority of women undergoing gynecological surgery develop postoperative adhesions. Sometimes these pelvic adhesions cause chronic pelvic pain and/or infertility.

Adhesions can cause a rare form of glaucoma called irido corneal endothelial (ICE) syndrome. In this disorder cells from the back surface of the cornea of the eye spread over the surface of the iris and the tissue that drains the eye, forming adhesions that bind the iris to the cornea and causing further blockage of the drainage channels. This blockage increases the pressure inside the eye, which may damage the optic nerve. ICE syndrome occurs most often in light-skinned females.

Causes and symptoms

Post-surgical adhesions

Common causes of postoperative adhesions include:

• abdominal surgery
• gynecological surgery
• thoracic surgery
• orthopedic surgery
• plastic surgery.

Abdominal adhesions most often result from surgeries in which the organs are handled or temporarily moved. Intrauterine adhesions form after surgeries involving the uterus, particularly curettage—the scraping of the uterine contents. Surgery to control uterine bleeding after giving birth also can lead to intrauterine adhesions. Such adhesions can cause Asherman's syndrome, closing the uterus and preventing menstruation.

Other causes of adhesions

Any inflammation or infection of the membranes that line the abdominal and pelvic walls and enclose the organs—the peritoneum—can cause adhesions. An example peritonitis, a severe infection that can result from appendicitis, may lead to adhesions. In addition to surgery or injury, pelvic adhesions can be caused by inflammation resulting from an infection such as pelvic inflammatory disease (PID).

Symptoms

In the majority of people adhesions do not cause symptoms or serious problems. However in some people adhesions can lead to a variety of disorders. The symptoms depend on the type of adhesion and the tissues that are involved. Adhesions may cause pain and/or fever in some people.

ABDOMINAL OBSTRUCTION. If a loop of intestine becomes trapped under an adhesion, the intestine may become partially or completely blocked. The symptoms of intestinal obstruction or SBOs due to adhesions depend on the degree and location of the obstruction. Partial or off-and-on intestinal obstruction due to adhesions may result in intermittent periods of painful abdominal cramping and other symptoms, including diarrhea.

Symptoms of significant intestinal obstruction due to adhesions include:

• severe abdominal pain and cramping
• nausea and vomiting
• abdominal distension (swelling)
• constipation and the inability to pass gas
• symptoms of dehydration.

Symptoms of dehydration include:

• dry mouth and tongue
• severe thirst
• infrequent urination
• dry skin
• fast heart rate
• low blood pressure.

In about 10% of SBOs, part of the intestine twists tightly and repeatedly around a band of adhesions, cutting off the blood supply to the intestine and resulting in strangulation and death of the twisted bowel. The mortality rate for strangulation of the bowel may be as high as 37%.

Symptoms of bowel strangulation due to adhesions include:

• severe abdominal pain, either cramping or constant

• abdominal distension due to the inability to pass stool and gas
• an extremely tender abdomen
• signs of systemic (body-wide) illness, including fever, fast heart rate, and low blood pressure.

When a portion of the obstructed bowel begins to die from lack of blood flow, fluids and bacteria that help digest food can leak out of the intestinal wall and into the abdominal cavity causing peritonitis.

PELVIC ADHESIONS. Pelvic adhesions can interfere with the functioning of the ovaries and fallopian tubes and are among the common causes of female infertility. Adhesions on the ovaries or fallopian tubes can prevent pregnancy by trapping the released egg. Adhesions resulting from endometriosis can cause pelvic pain, particularly during menstruation, as well as fertility problems.

Diagnosis

Adhesions are diagnosed based on the symptoms, surgical history, and a physical examination. The physician examines the abdomen and rectum and performs a pelvic examination on women. Blood tests and chest and abdominal x rays are taken. Sometimes exploratory surgery is used to locate the adhesions and sources of pain.

Abdominal computed axial tomography—a CT or CAT scan—is the most common diagnostic tool for SBO and intestinal strangulation due to adhesions. In this procedure a computer reconstructs a portion of the abdomen from x-ray scans. Barium contrast x-ray studies also may be used to locate an obstruction. The ingestion of a barium solution provides better visualization of the abdominal organs. However sometimes intestinal obstruction or strangulation cannot be confirmed without abdominal surgery.

Exploratory laparoscopy may be used to detect either abdominal or pelvic adhesions. This procedure usually is performed in a hospital under local or general anesthesia. A small incision is made near the naval and carbon dioxide gas is injected to raise the abdominal wall. A tube called a trocar is inserted into the abdomen. The laparascope, equipped with a light and a small video camera, is passed through the trocar for visualization of the peritoneal cavity and the abdominal or pelvic organs.

Pelvic adhesions also may be detected by hysteroscopy. In this procedure a uterine endoscope is inserted through the cervix to visualize the cervix and uterine cavity. With hysterosalpingography (HSG) a radiopaque or contrast dye is injected through a catheter in the cervix and x rays are taken of the uterus and fallopian tubes.

Treatment

Although the symptoms of adhesion disease sometimes disappear on their own, adhesions are permanent without a surgical procedure called adhesion lysis to disrupt or remove the tissue.

Abdominal adhesions

Sometimes an adhesion-trapped intestine frees itself spontaneously. Surgery may be used to reposition the intestine to relieve symptoms. Various other techniques include using suction to decompress the intestine; however untreated intestinal adhesions may lead to bowel obstruction.

Although dilation with an endoscope may be used to widen the region around an intestinal obstruction to relieve symptoms, SBOs caused almost always require immediate surgery. In cases of a partial obstruction or a complete obstruction without severe symptoms, surgery may be delayed for 12-24 hours so that a dehydrated patient can be treated with intravenous fluids. A small suction tube may be placed through the nose into the stomach to remove the stomach contents to relieve pain and nausea and prevent further bloating.

If an adhesion-related SBO disrupts the blood supply to part of the intestine, gangrene—tissue death—can occur. Strangulation of the bowel usually requires emergency abdominal surgery to remove the adhesions and restore blood flow to the intestine. Intestinal obstruction repair is performed under general anesthesia. An incision is made in the abdomen, the obstruction is located, and the adhesions are cut away, releasing the intestine. The bowel is examined for injury or tissue death. If possible, injured and dead sections are removed and the healthy ends of the intestine are stitched together (resectioned). If resectioning is not possible, the ends of the intestine are brought through an opening in the abdomen called an ostomy.

In some cases laparoscopic surgery can be used to removed damaged portions of the intestines. Five or six small incisions—0.2-0.4 in. (5-10 mm) in length—are made in the abdomen. The laparoscope, equipped with its light and camera, and surgical instruments are inserted through the incisions. The laparoscope guides the surgeon by projecting images of the abdominal organs on a video monitor. However the existence of multiple adhesions may preclude the use of laparoscopic surgery.

Other types of adhesions

Adhesions caused by endometriosis may be removed by either traditional open abdominal or pelvic surgery or by laparoscopic surgery. In the latter technique the laparoscope includes a laser for destroying the tissue with heat. Although untreated gynecological adhesions can lead to infertility, both types of surgeries also can result in adhesion formation.

ICE-type glaucoma caused by adhesions is difficult to treat; however untreated ICE syndrome can lead to blindness. Treatment usually includes medication and/or filtering surgery. Filtering microsurgery involves cutting a tiny hole in the white of the eye (the sclera) to allow fluid to drain, thereby lowering the pressure in the eye and preventing or reducing damage to the optic nerve.

Alternative treatment

In cases where the intestines are partially blocked by adhesions, a diet low in fiber—called a low-residue diet—may enable food to move more easily through the obstruction.

Prognosis

Intestinal obstruction surgery usually has a favorable outcome if the surgery is performed before tissue damage or death occurs. Surgery to remove adhesions and to free or reconnect the intestine often is sufficient for reducing symptoms and returning normal function to the intestine or other organ. However the risk of new adhesion formation increases with each additional surgery. Thus abdominal adhesions can become a recurring problem. Adhesions reform in 11-21% of patients who have surgery to remove an adhesion-related intestinal obstruction. The risk of recurrence is particularly high among survivors of bowel strangulation.

Prevention

Abdominal and gynecological laparoscopic surgeries—also known as "keyhole" surgeries—reduce the size of the incision and the amount of contact with the organs, thereby lowering the risk of adhesion formation. Sometimes the intestines are fixed in place during surgery so as to promote benign adhesions that will not cause obstructions.

Within five days after surgery the disturbed tissue surfaces have formed a new lining of mesothelial cells that prevent adhesions from forming. Therefore biodegradable barrier membranes, films, gels, or sprays can be used to physically separate the tissues after surgery to prevent the formation of postoperative adhesions. However these gels and other barrier agents may:

• suppress the immune system
• cause infection
• impair healing

Systemic anti-inflammatory medications may be used to help prevent adhesion formation. Recent studies suggest that the common oral arthritis drug, Celebrex, an anti-inflammatory COX-2 inhibitor, taken before and immediately after surgery, may help prevent abdominal adhesions. Celebrex is known to inhibit both the formation of blood vessels and fibroblast activity, which are necessary for the formation of scar tissue.

Recent research has focused on the incorporation of anti-inflammatory and anti-proliferation drugs into polymeric films used for preventing and treating post-surgical adhesions. New types of gels to prevent postoperative adhesions also are under development.

Resources

BOOKS

Baerga-Varela, Y. "Small Bowel Obstruction." Mayo Clinic Gastrointestinal Surgery, edited by K. A. Kelly, et al. St. Louis, MO: Elsevier Science, 2004.

PERIODICALS

"Surgical Complications; Celebrex Prevents Adhesions After Surgery." Science Letter (February 15, 2005): 1443.

ORGANIZATIONS

National Digestive Diseases Information Clearinghouse. 2 Information Way, Bethesda, MD 20892-3570. 800-891-5389. 301-654-3810. 〈http://digestive.niddk.nih.gov/〉.

OTHER

Abdominal Adhesions. Aetna InteliHealth. February 17, 2004 [cited March 2, 2005]. 〈http://www.intelihealth.com/IH/ihtIH/WSIHW000/9339/9394.html〉.

Endometriosis. MayoClinic.com. September 11, 2003 [cited March 2, 2005]. 〈http://www.mayoclinic.com〉.

Infertility. MayoClinic.com. September 21, 2004 [cited March 2, 2005]. 〈http://www.mayoclinic.com/invoke.cfm?id=DS00289〉.

"Intestinal Adhesions." Digestive Diseases. National Digestive Diseases Information Clearinghouse. February 2004 [cited February 21, 2005]. 〈http://digestive.niddk.nih.gov/ddiseases/pubs/intestinaladhesions/index.htm〉.

What is Glaucoma? Glaucoma Research Foundation. [Cited March 4, 2005]. 〈http://www.glaucoma.org/learn/〉.