Adhesions are a form of internal scar tissue that develops within the abdominal and pelvic cavities, connecting tissues and organs that are normally separate and free-moving. These bands of fibrous tissue cause internal structures, such as the small intestine or reproductive organs, to stick to one another or to the inner abdominal wall. The surfaces of organs within the abdomen are typically slick, allowing them to glide smoothly, but adhesions disrupt this natural mobility. Although many people with adhesions remain entirely without symptoms, their formation is a frequent outcome of abdominal trauma, especially following open surgery.
The Nature and Formation of Adhesions
Adhesion formation is a biological response to tissue injury, reflecting the body’s attempt to heal damage. When the protective lining of the abdomen, the peritoneum, is traumatized, an inflammatory response begins. This process activates the coagulation cascade, leading to the rapid deposition of fibrin, a protein that acts as a temporary biological glue on the injured surface.
Normally, the body’s fibrinolytic system dissolves this temporary fibrin matrix within a few days, allowing tissue repair without permanent scarring. If the injury is extensive or fibrinolytic activity is impaired, however, the fibrin persists.
When fibrin is not broken down, specialized cells called fibroblasts migrate into the matrix. These fibroblasts remodel the extracellular matrix, replacing the temporary fibrin scaffolding with permanent, dense connective tissue composed primarily of collagen. This conversion forms the adhesion, which is a permanent, fibrous band. The resulting tissue can range from thin, veil-like sheets to thick, cord-like structures that tether organs together.
Common Triggers and Risk Factors
Prior abdominal surgery is the most frequent catalyst for adhesion formation and is responsible for the majority of recognized cases. The trauma of incision, handling organs, and tissue drying during an open procedure triggers the healing response that leads to internal scarring. Adhesions develop in over 90% of individuals following traditional open abdominal surgery.
Minimally invasive laparoscopic surgery reduces the risk but does not eliminate it. Operations in the lower abdomen, such as gynecological procedures or bowel resection, carry a high risk. The risk also increases significantly with the number of previous abdominal operations a person has undergone.
Other sources of inflammation or injury can also act as triggers. These include infections within the abdominal cavity, such as peritonitis or pelvic inflammatory disease (PID). Chronic inflammatory conditions like endometriosis, Crohn’s disease, or diverticulitis promote scar tissue formation. Trauma, such as from radiation therapy, can also disrupt the peritoneal lining and initiate adhesion development.
Recognizing Symptoms and Potential Complications
Most adhesions cause no noticeable issues, but when they become symptomatic, the primary complaint is chronic abdominal or pelvic pain. This pain occurs because the fibrous bands restrict the natural movement of organs, causing them to pull on surrounding tissues. The discomfort is often described as a vague, cramping sensation that is intermittent and difficult to pinpoint.
The most severe complication is adhesive small bowel obstruction (SBO), which is a medical emergency. Adhesions can kink, twist, or compress the small intestine, blocking the passage of food, fluid, and gas. Symptoms of a complete SBO include severe, colicky abdominal pain, bloating, persistent nausea and vomiting, and an inability to pass gas or stool.
If the obstruction is not resolved promptly, it can lead to strangulation, a lack of blood flow to the blocked section of the intestine. This can cause tissue death and potentially perforation, leading to a life-threatening infection. Symptoms can appear years or decades after the initial event, as the scar tissue may tighten over time.
Adhesions can also affect female reproductive health by distorting the fallopian tubes and ovaries. This physical interference can prevent conception or impede the movement of a fertilized egg, leading to infertility.
Clinical Diagnosis and Management Options
Diagnosing abdominal adhesions is challenging because the fibrous bands are difficult to visualize using standard medical imaging. Routine tests like X-rays and computed tomography (CT) scans cannot reliably detect adhesions directly. These imaging studies are primarily used to identify complications, such as the location and severity of an intestinal blockage.
A physician relies heavily on a person’s clinical history, especially prior abdominal surgeries, and the pattern of symptoms to suspect adhesions. Definitive diagnosis is often only achieved during an exploratory surgical procedure, most commonly a laparoscopy, where the surgeon can directly view the internal organs.
Management Strategies
Management depends on the severity of symptoms and complications. For individuals with mild, chronic pain, non-surgical approaches are used, including dietary modifications to prevent partial obstructions and pain management medications. Physical therapy, particularly soft tissue mobilization, can help improve scar mobility and reduce chronic pain.
When adhesions cause a severe complication like SBO, or when chronic pain is debilitating, surgical intervention may be necessary. The procedure to surgically cut or remove the adhesions is called adhesiolysis, which aims to restore the free movement of the organs.
Adhesiolysis can be performed through traditional open surgery or a minimally invasive laparoscopic approach. The laparoscopic approach is generally associated with a reduced risk of forming new adhesions. However, any abdominal surgery, including adhesiolysis, carries the risk of causing new adhesions to form, so the procedure is reserved for necessary cases.