Evacuation Proctogram - Uses, Procedure, Results, Benefits, and Risks

Introduction:

During World War II, in 1945, defecating proctography was invented. The surgery became well-known during this period due to a whipworm outbreak, which has been linked to rectal prolapse. Since then, it has been utilized to diagnose several anorectal conditions, such as anismus and other reasons for obstructed feces. The lack of sufficient training in the method has caused it to become less popular. These days, just a few institutions perform it. The process is commonly referred to as the def proc, defogram, or stool finale by radiology residents.

What Is an Evacuation Proctogram?

An evacuation proctogram is a medical imaging test that uses X-rays to study the process of a patient’s defecation. It evaluates the structure and function of the lower bowel and rectum, thereby evaluating the rate and completeness of rectal clearing. It also identifies any structural abnormalities that could result in obstructive disorders. This procedure is also known as defecography, proctography, defecating/defecation proctography, evacuation proctography, or dynamic rectal examination.

What Are the Uses of This Procedure?

It is widely used to analyze the disorders of defecation that could be as mentioned below:

• Difficult defecation (incomplete or obstructed).

• Constipation.

• Pelvic floor disorders such as pelvic pain, anal pain, and rectal prolapse.

• Fecal incontinence.

• Leakage of stool.

• The feeling of either a full rectum or incomplete clearing.

• In conditions such as rectocele (a disorder brought on by weakening pelvic floor muscles that cause the rectum to protrude into the vaginal wall), enterocele, sigmoidocele, internal rectal intussusception, and anismus (a medical disorder when the pelvic floor muscles and nerves malfunction, making it difficult to pass feces).

• It is also used to evaluate the surgical repair of obstructive cases of defecation.

What Are the Preparations Needed Before This Procedure?

• The patient should wear loose, comfortable clothes.

• Can continue their normal diet and medications.

• Any history of barium allergy should be mentioned to the doctor.

• Ladies who think they are or they might be pregnant should inform the doctor before the procedure.

• Preparing the bowel before surgery is optional as well. To further identify movement of the vagina and small bowel concerning the rectum during defecation, additional optional steps include opacification of these tissues. For men, rectum opacification is all that is needed.

• Vagina:

  1. The amount of vaginal contrast utilized varies throughout hospitals, while some use five milliliters.

  2. When compared to oral barium, barium should be more dense.

  3. Not carried out if the patient has never engaged in sexual activity

• Small intestine:

  1. 500 milliliters of oral barium.

  2. Hold off for thirty to sixty minutes.

  3. Add 200 ml of barium and wait an additional 30 to 60 minutes if the scout radiograph does not show the terminal ileum.

How Is This Procedure Done?

• Patients are required to change into a hospital gown.

• They would be given six ounces of barium to drink half an hour before the examination procedure.

• The patient would then be taken to the examination room. They will be asked to lie on their side.

• Thick barium paste will be injected through a miller catheter into the rectum.

• In female patients, a small amount of barium paste will also be inserted into the vagina to check for enterocele, rectocele, or sigmoidocele.

• First, X-ray images are taken when the patient is lying on the table in three positions: resting, squeezing, and straining the pelvic floor muscles.

• The patient is then asked to sit on a special commode which is also known as a defecography chair, and X-ray images will be taken while defecating.

• The patient will be asked to cough, strain, do the kegel maneuver, and then finally evacuate. X-ray images will be taken in all these positions.

• Post-evacuation images also should be taken to check for any retained material.

• The entire procedure may take one to one and a half hours.

Always keep in mind that this is a very extensive and sensitive examination for the patient, even if it is standard procedure for the radiologist and technician. At all times, the patient should have the highest level of privacy.

How Are the Results Interpreted?

The key measurements used in the evacuation proctogram are as mentioned below:

1. Anal Canal Length - This is calculated when evacuation is at its highest.

2. Anal canal Width - This is typically less than 2.5 cm when measured during maximal evacuation.

3. Effectiveness of Evacuation or Emptying - 90 to 100 percent of the rectal contents are typically evacuated.

4. Anorectal Angle -

• The strength of the puborectalis muscle is related to the anorectal angle.

• Anorectal junction descends to the level of ischial tuberosities.

• The anorectal angle is 90 to 100° at rest, acute (70 to 90°) when contracting, and obtuse (110 to 180°) while evacuating.

5. Perineal Descent -

• The pelvic floor comes down a few centimeters on straining and rises back on relaxation.

• The reference line taken is from the tip of the coccyx to the lower border of the pubic ramus.

• The ideal range is 4 cm from the reference line.

The following conditions can be diagnosed:

• Anismus: It has been proposed that this procedure, which yields aberrant defecation findings, may cause embarrassment to certain individuals. For instance, the patient might not be able to relax in these circumstances, which could result in a false-positive diagnosis of anismus and a puborectalis relaxation failure.

• Rectoceles: A rectocele is the most frequent finding with this kind of imaging. This is almost often an anterior rectocele, in which the female vagina is accessed by the anterior rectal wall protruding forward. Rectoceles, particularly anterior rectoceles, are uncommon in men because the prostate gland provides greater support in this area than the vaginal cavity does. A less prevalent condition that affects mostly men, posterior rectoceles are caused by a posterior bulging of the rectum.

• Sigmoidocele and Enterocele: An enterocele is a peritoneal prolapse, including a portion of the small intestine. A sigmoidocele is a peritoneal prolapse, including a piece of the sigmoid colon. These prolapses typically occur in females between the vagina and the rectum. The most common way to see them is during straining.

The other conditions that could be seen with this procedure include rectal prolapse or internal rectal intussusception (a disorder when the rectum protrudes through the anus, frequently as a result of nerve injury, weakening muscles, or protracted constipation), megarectum (this is an incomplete evacuation and an abnormal breadth (greater than nine centimeters) of the rectum), and fecal incontinence.

What Are the Instructions After the Procedure?

• Patients need to drink plenty of water for 24 to 48 hours.

• For several days the stool may tend to remain white due to barium.

• Barium can also cause constipation; hence patients may include a high-fiber diet.

What Are the Risks Associated With This Procedure?

• Minimal radiation exposure.

• Constipation for a few days after the procedure.

• It is contraindicated in pregnant ladies.

Conclusion:

A sensation of incomplete bowel emptying can be the most frustrating and stressful incident, affecting the quality of life. Nevertheless, with timely intervention, this problem can be managed with ease. There are many imaging techniques present for assessing defecation disorders; however, the most commonly used is the evacuation proctogram. The thought of emptying the bowels in an x-ray room is challenging, yet this diagnostic procedure marks an important step to proper diagnosis and treatment, thereby improving one’s quality of life.