Posterior Sagittal Anorectoplasty (PSARP)

Overview

Anorectal malformations are birth deformities caused by inappropriate development of the anus and rectum (the lower end of the digestive system). This might make it difficult for your child to pass feces. The majority of newborns with anorectal malformations will require surgery to be corrected.

Anorectal malformations (ARMs) may be corrected in 90% of newborn boys with a posterior sagittal approach alone, whereas 10% require an additional abdominal component (with laparotomy or laparoscopy) to mobilize a very high rectum. With the exception of around 30% of cloacas, all ARMs in newborn females may be corrected using the posterior sagittal technique. The rectum or vagina is high enough in these 30% to necessitate an abdominal approach.

the surgeons utilize posterior sagittal anorectoplasty (PSARP) to treat a variety of anorectal and cloacal abnormalities. PSARP and its modifications utilizing laparoscopic technology give higher accuracy in relocating the rectum and anus, minimize damage to adjacent anatomical tissues, reduce post-operative discomfort, and enhance outcomes. The majority of pull-through surgeries are performed on children aged one to six months.

The specific PSARP operation, your kid will undergo is determined by whether the deformity is "high" or "low." This specifies where the rectum (the bottom portion of the intestine) finishes within the abdomen, the strength of the pelvic sphincter muscles, and whether or not there is a fistula - an abnormal channel that forms between organs that can allow feces to travel into other areas of the belly. This is often between the rectum and the urinary system in males.

What are Anorectal Malformations in Children?

Anorectal malformations are birth abnormalities or problems that occur during the development of an unborn infant during pregnancy. The anus and rectum do not grow normally due to this abnormality. They are located at the bottom of the digestive system.

• Ano means the anus. This is the opening at the end of the large intestine. Stool passes through here when there is a bowel movement.
• Rectal means the rectum. This is the part of the large intestine just above the anus.

Normally, feces move from the large intestine to the rectum and finally to the anus during a bowel movement. When you have a bowel movement, the muscles in the anal region help to regulate it. The nerves in the region assist the muscles in detecting the need for a bowel movement. Muscle action is also stimulated by the nerves.

Several problems might arise as a result of an anorectal malformation. These include: 

• A tissue or membrane may be used to close the anal orifice.
• The rectum may not be connected to the anus.
• The rectum may link to the urinary tract or the reproductive system. This occurs via a fistula.
• Anorectal abnormalities interfere with a child's bowel movement. Treatment is determined on the type of problem, your infant has.

What Causes Anorectal Malformations?

Different organ systems develop and mature as an unborn baby grows in its mother's womb, or uterus. Early in pregnancy, the lower end of the digestive tract develops.

The bottom half of the large intestine and the urinary tract begin as one big mass of cells in an unborn baby. Certain steps must be followed throughout the first three months of pregnancy or gestation. These processes are required for the rectum and anus to separate from the urinary system and correctly develop. These stages do not always take place as they should. The rectum or anus may not grow properly as a result. In most situations, it is unknown what causes this to occur.

Some genetic syndromes or congenital issues that are present at birth might cause anorectal malformation. These are some examples:

• VACTERL association. This disorder includes problems with the spine, anus, heart, trachea, esophagus, kidneys, and arms and legs.
• Digestive system problems.
• Urinary tract problems.
• Spinal problems.
• Down syndrome.
• Townes-Brocks syndrome. This syndrome includes problems with the anus, kidneys, ears, and arms and legs.

What Conditions Does PSARP Treat?

PSARP has been adapted to treat several conditions, including:

• Cloaca.
• Urogenital sinus anomaly, a rare birth defect that causes the urethra and vagina to merge into one.
• Pre-sacral masses, which are tumors in the space between the rectum and the bottom of the spine.
• Acquired recto-urethral fistulas, a rare connection of the lower urinary tract and rectum.
• Recto-vaginal fistulas, an abnormal connection between the rectum and vagina.
• Vaginal atresia, a birth defect in which the vagina is closed or absent.
• Reoperations for Hirschsprung disease and other urogenital anomalies.

Anorectal Symptoms Needs PSARP

Abnormal bowel motions are caused by anorectal malformations such as imperforate anus. These issues differ based on the type of malformation:

• If your baby's anal canal is narrow, he or she may have difficulty passing a stool, resulting in constipation and even pain.
• If a membrane forms across the anal orifice, your baby may be unable to urinate.
• If the rectum is not attached to the anus but a fistula exists, feces will exit your baby's body via the fistula and enter the urinary tract rather than the anus. This might result in a urinary infection.
• There is no method for the feces to escape the gut if the rectum is not attached to the anus and there is no fistula. As a result, your kid will be unable to have a bowel movement and will have an intestinal blockage as a newborn.

What is Posterior Sagittal Anorectoplasty (PSARP)?

A PSARP is a type of pull-through surgery done in some children to treat anorectal malformations. The child's anus is surgically created within the sphincter muscle using this procedure. If there is no space for stool to pass through prior to surgery, your child's surgeon may use a type of x-ray called a colostogram to identify the degree and location of the abnormality. The PSARP procedure is often performed within the first year of your baby's life.

If necessary, your child will have already had a colostomy surgery performed at birth. The large intestine is divided into two portions in a colostomy, and the ends of the intestine are delivered through holes in the belly. The top part permits feces to flow through an opening (referred to as a stoma) and into a collecting bag. Mucus generated by the gut might flow through the lower part into a collecting bag. Your baby's digestion will be unaffected by the colostomy, and they will be able to develop before the next procedure.

How Do You Prepare Your Child Before Surgery?

• Children with certain types of malformations must visit the hospital the day before surgery for bowel preparation.
• If your kid does not need to be admitted to the hospital the day before surgery, the nurse will contact you 48 hours (2 days) before the procedure. They will talk about: 

1. Eating and drinking rules. 
2. When you have to get to the hospital.

• If your kid is on medication, consult with a doctor. Do not give your child any medicine on the morning before surgery unless instructed to do so by his or her doctor.

The health care team will ensure that your kid is ready for surgery on the day of surgery by doing a comprehensive physical exam and imaging studies:

Physical exam:

A doctor will check a newborn from head to toe shortly after birth. During this evaluation, doctors frequently diagnose anorectal abnormalities. Doctors will also evaluate the baby's perineum and genitals for any birth abnormalities.

Imaging tests:

Doctors may use the following tests to examine defects of the anus and rectum:

• Ultrasound, which uses sound waves to create an image of organs.
• X-rays, which use a small amount of radiation to create pictures of the inside of the body.
• Magnetic resonance imaging (MRI), which takes pictures of the body’s internal organs and soft tissues without using x-rays.

What Happens During the Posterior Sagittal Anorectoplasty (PSARP)?

The patient is put in a prone posture with the pelvis raised and the operating table in a Trendelenburg position to execute the anorectal reconstruction. Before and during the procedure, an electrical stimulator is utilized to map the sphincter.

The length of the incision is determined by the amount of exposure required for safe repair of the particular ARM. A perineal fistula, for example, requires only a 2 cm posterior sagittal incision, whereas more complex defects may necessitate a full posterior sagittal incision that runs from the lower sacrum to the base of the scrotum in males or to the single perineal orifice in females with cloacal malformation.

In the midline, the incision separates the parasagittal fibers, muscular complex, and levator muscles by separating the skin and subcutaneous tissue. Only the parasagittal fibers and the muscle complex in the midline are separated in less complicated lesions (perineal and vestibular). The levator muscle isn't visible.

Once the sphincter mechanism has been split, the rectum must be separated from the urogenital structures. The rectum is instantly visible in perineal and vestibular fistulas, and several silk sutures are put on the rectum to produce equal traction and so promote safe separation from neighbouring tissues. Even in these minor ARMs, the rectum must be entirely separated from its anterior attachments to the urethra or vagina. Failure to do so puts the anoplasty under tension, which leads to many failure repairs.

Repairing a rectourethral fistula in a male follows many of the same basic principles, but there are a few key changes. At the start of the surgery, a urinary catheter must be introduced, and a Coude tip catheter helps prevent accidental entry into the rectal fistula.

The rectum is first found using the posterior sagittal incision. Before beginning the treatment, the surgeon must know exactly where to look for the rectum. As a result, the significance of a precise distal colostogram in avoiding damage to surrounding structures cannot be emphasized. The rectum will lay slightly behind the levator muscles in the event of a bulbar urethral fistula, and considerably higher, under the coccyx, in the case of a prostatic urethral fistula.

The surgeon should try to identify the rectum after opening the parasagittal fibers, muscle complex, and levators. After the rectum has been recognized with confidence, it should be moved laterally and posteriorly. The rectum should next be opened in the midline using silk traction sutures. Multiple stitches are then inserted on the rectum's margins as it is opened inferiorly, precisely in the midline. After identifying the fistula, a line of silk sutures is put proximal to the fistula.

The rectum and urethra's shared wall is then gently separated. To avoid urethral damage, the first 1-2 mm of separation should be performed in a submucosal rectal plane. The dissection is aided by finishing the lateral rectum dissection before trying the anterior plane. Once the rectum has been entirely separated from the urethra, the fistula can be repaired with long-term absorbable sutures, and the rectum can be moved further to allow for tension-free anoplasty.

What Happens After the Procedure?

• Your child will be hospitalized for many days following surgery.
• They will most likely experience little discomfort as a result of the incision. A strategy will be devised to aid in their comfort.
• For a few days following surgery, your kid may require a special tube to empty urine (pee) from the bladder.
• The doctor will show you how to take care of your child's incision.

1. Anal dilations will begin two (2) to four (4) weeks following surgery. This will prevent the anus from narrowing while it heals. Here are some details you should be aware of:
2. A dilator (medical rod) is used to prevent your child's new anus from narrowing.
3. It is critical that the family adhere to the plan that has been provided to them.
4. The first dilator will be administered by the surgeon.
5. The dilations will be taught to you by the surgeon or nurse. You will perform them twice a day, once in the morning and once in the evening.
6. They are done twice a day, once in the morning and once in the evening, but make sure you follow the dilation plan that was given to you.
7. If the dilation strategy is not followed correctly, your kid may require further surgery.

• If your child has a colostomy, it can be closed by surgery about 8-12 weeks after PSARP.

What Should you Expect During your Child's Recovery?

You may be surprised at how quickly your child recovers following PSARP surgery.

Patients with colostomies must stay in the hospital for 24 to 48 hours following PSARP surgery before being discharged. Male patients whose rectum opened into the urinary system (the majority of male patients) have an outpatient clinic visit seven days following surgery to have the Foley catheter removed.

Patients visit an outpatient clinic appointment 14 days following surgery to learn how to do anal dilations. This keeps your child's newly formed anus open to the proper size and is typically not painful.

What Happens if PSRAP Not Done?

If anorectal abnormalities are not identified and corrected soon after birth, the infant may develop signs of intestinal blockage, such as vomiting, bloating, or apparent enlargement of the abdomen, and inability to pass stool. Intestinal blockage can result in significant problems such as a hole in the gut wall known as a perforation, severe infection, and sepsis.

Some patients who have had anorectal abnormalities surgically repaired may develop difficulties later in life, including as

• Constipation.
• Bowel control problems.
• Bladder control problems.
• Problems with sexual function.

When Should You Call the Pediatric Surgeon?

If an anorectal malformation was not discovered in the hospital but your kid has the following symptoms:

• Passes stool from her vagina.

• Passes stool in the urine.
• Passes urine from the anus.
• Has constipation.

If your baby does not pass stool, it is a medical emergency. You should seek medical care right away.

Conclusion

Birth disorders in which the anus and rectum (the bottom end of the digestive system) do not develop normally are known as anorectal malformations. They affect around 1 in every 4,000 babies and can range from mild to severe.

Doctors frequently do surgery within the first few days following a baby's birth. In certain situations, surgeons can fix the anorectal malformation in a single procedure. In some circumstances, a colostomy is performed first to connect the colon to a stoma, a hole in the abdomen that permits feces to escape the body. When the infant is older, surgeons will fix the anorectal abnormality with one or more procedures.

A posterior sagital anorectoplasty (PSARP), also known as a pull-through operation, is a surgical treatment used to correct anorectal malformations or anomalies of the rectum and/or anus. Many different types of abnormalities can occur in children. Your child's doctor will examine him or her and do a set of tests to determine the type of problem. They will then talk about the best treatment approach for your child. This frequently includes surgery.