Anoplasty

Overview

An anoplasty is an anorectal procedure that involves reconstructing or fixing issues that keep the anus from functioning properly. Certain defects manifest at birth, while others result from injury or illness.

The anus serves as the terminal point of the large intestine, comprising a relatively short tube, approximately 3 to 4 centimeters in length. It is encircled by sphincter muscles, which facilitate the expulsion of fecal matter from the body. 

Anoplasty may be necessary if surgery or a medical condition has led to the narrowing of the anal canal due to scar tissue. For a child, this procedure might be required if they are born with an abnormal anus.

Reasons for undergoing the procedure

Anoplasty may be recommended due to the certain health conditions, such as:

• Anorectal malformations: These are congenital defects that occurs when a baby is born with an improperly developed anus or rectum. Imperforate anus is a medical condition characterized by the absence or obstruction of the opening to a baby’s anus. A perineal fistula involves an incorrectly positioned anal opening that circumvents the anal muscles and opens in the perineum. Typically, the opening is narrow and lacks muscular control.
• Anal stenosis: Also known as stricture, is characterized by increased thickness of the anal walls caused by scar tissue, impeding anal walls’ ability to stretch and allow the passage of stool. In cases of severe stenosis when other treatments prove ineffective, anoplasty may be required. Typically seen in adults, it commonly arises as a consequence of anorectal surgery or chronic illness.

Risk

There are several risks associated with anoplasty. Potential long–term complications include stenosis, which may arise if regular dilation of the anus is not performed during the healing process. 

There is also a rare but possible risk of developing fistulas due to an internal infection post–surgery, causing a hole in the anus. In such cases, a subsequent surgical procedure is typically required to close the fistula. Other long–term complications include:

• Fecal incontinence: It can be difficult to control the bowel movements after surgery because it can damage the muscles or nerves that regulate bowel movement. It is possible that individuals with anorectal abnormalities are born without the required muscles and nerves to regulate bowel movement. Over time, some people will learn to regulate their bowels, while others won’t. Bowel training as well as daily cleansing may be part of the recovery process.
• Diaper rash: Ointments can be used to treat, and assist prevent it. Diaper rash is merely a result of the skin’s lack of prior feces exposure. When babies initially start pooping out of their anus, it is usual for them to get a severe rash.

Anoplasty also comes with short–term complication, such as:

• Infection: Recovery may take longer than eight weeks if a wound becomes infected during the healing process.
• Hematoma: Healing may also be impeded by hematoma, which is an accumulation of pooled blood within the healing tissues. In some instances, a minor procedure may be necessary to drain this collection. Common treatment involves the application of ice and compression.
• Urinary retention: Medication or a catheter may be used by some patients who may experience trouble urinating following surgery. 
• Constipation: Following the procedure, certain individuals may experience constipation, particularly if they have a history of constipation. Chronic constipation in the past might have conditioned the body to reduce its bowel movement. In such cases, medication may be required to stimulate and regulate bowel movements. 

Before the procedure

Prior to the procedure, a bowel preparation kit is provided to facilitate emptying of bowels in preparation for the treatment. This kit usually consists of an oral laxative formula that one will take the day before the procedure, effectively emptying their bowels. 

A specific diet may be prescribed for several days, typically starting with a low–fiber diet for two days and then transitioning to only clear liquids on the final day before taking the formula.

During the procedure

Anoplasty typically begins with administering general anesthesia. The procedure involves utilizing an electric stimulator machine. This device helps induce contractions in the anal muscles, assisting healthcare providers in precisely locating the two sphincter muscles that define the two ends of the anus or its intended position.

Anoplasty aims to restore or establish a functional anal canal, and the approach to the procedure is usually tailored to one’s condition.

• Anorectal malformations: Anoplasty for this condition involves a newly formed anal canal that seamlessly extend from the rectum, passing through the anal sphincter muscles to open at the end. Constructing a new anus is usually done when a baby is born with missing or misplaced anus. Surgeons may be required to reposition or seal off abnormal openings known as fistulas that deviate from the usual route. In the case of a temporary colostomy in a newborn, it will be maintained for the time being. While healing, the entrance to their new anus will be sealed, keeping the rectum closed.
• Anal stenosis: If scar tissue restricts the function of your anus, your surgeon will perform a procedure to remove the scar tissue, enabling your anus to relax and expand. This will result in the restoration of your anus to its natural dimensions. 

However, this procedure results in a gap in the inner lining. To address this, skin flap from the perianal region, which is located inside the buttocks just outside of the anus, will be removed. Leaving it attached on one side, the flap will be used to cover the gap and the perianal wound will be closed with stitches. 

After the procedure

One might also leave the hospital the same day or stay there for a few days, depending on how complex the procedure was. Follow–up visits will be scheduled frequently in the weeks following the procedure to monitor the healing process. 

As part of the recovery, performing regular anal dilations may be required. This involves inserting a specialized dilator into the anus daily to facilitate stretching. The purpose of this dilation is to train the tissues, ensuring that the new anus settles at the correct diameter and helps prevent narrowing and scarring during the healing phase.

Outcome

Constipation might be experienced, and a specific diet to follow may be recommended during the recovery phase. Pain management medication may be prescribed as an anorectal procedures typically involve low pain threshold.

The recovery period, which involves daily dilations, typically spans four to eight weeks. It is normal for the anus to experience minor bleeding during these daily dilations, which is generally not very painful. After the complete healing of the anus, infants with colostomies will be prepared for their final surgery to reverse the colostomy.