Overview of Abdominoperineal Resection
Abdominoperineal resection, also known as APR, is a type of operation where the rectum and anus are removed. This often leads to the creation of a permanent opening, called an end colostomy, on the abdomen for waste to leave the body. This surgery is typically done for low rectal cancers or anal cancers that don’t respond to treatment or keep coming back. There are other nonmalignant conditions such as severe injury, perianal Crohn’s disease (a type of inflammatory bowel disease that causes inflammation in the digestive tract), and complex anorectal fistulae (abnormal connections or passageways between the rectum or other anorectal area and the skin or organs) that may also require this surgery.
During this surgery, the rectum, anal sphincter complex (muscles that allow us to control our bowel movements), and anus are removed, and the resulting opening in the perineal area (the area between the anus and the genitals) is stitched closed. The surgeon then brings out the lower part of the colon through an opening in the abdomen, creating a permanent end colostomy. Depending on the disease severity, patient’s condition, and specific medical issue, the extent of the operation and removal of surrounding structures can vary.
Thanks to advances in diagnosis techniques, radiation therapies, and chemotherapy treatments, the need for APRs is becoming less common, as we now have ways to save the sphincter muscles. The surgery, which traditionally required making two large cuts in the abdomen and the perineal area, can now often be performed with less invasive methods such as laparoscopy (surgery done through small cuts using a camera) or robotic surgery.
It’s important to note that APR comes with significant health risks. Patients who undergo this procedure will live with a permanent colostomy and may have urinary and sexual dysfunction that can greatly impact their quality of life. This is why thorough counseling, emotional support, skilled surgical techniques, and good care before, during and after the surgery are absolutely crucial to helping patients have the best possible outcomes.
Anatomy and Physiology of Abdominoperineal Resection
APR, or abdominoperineal resection, is a type of surgery mainly used to treat lower rectal cancers. It involves removing key structures in the pelvic and lower digestive areas. To understand the complexity of this procedure and how it might affect the patient, it’s important to know about the parts of the body it involves: the left colon, sigmoid colon, rectum, pelvic floor, anus—and a group of important muscles called the anal sphincter complex.
The left colon starts where the transverse colon, which lies horizontally across the abdomen, turns downward to become the descending colon. This portion, including the sigmoid colon, makes up the left colon. The sigmoid colon is an S-shaped segment of the large intestine that’s connected to the rectum. The blood supply for these parts comes mainly from the left colic artery and the sigmoid arteries, both branches of the inferior mesenteric artery (IMA—a major artery supplying the large intestine). During the surgery, the left and sigmoid colon are moved to access the area, and their blood supply is redirected to prevent blood flow problems in the remaining intestine.
The rectum, where the sigmoid colon ends, is about 12 to 15 cm long and is located within the pelvic cavity. It has three parts: the upper, middle and lower thirds. Depending on the part, it is covered partially or completely by the peritoneum (a thin layer that lines the abdomen). Its main blood supply comes from the superior rectal artery (an extension of the IMA), the middle rectal artery (a branch of the internal iliac artery, which supplies the pelvic area), and the inferior rectal artery.
The anal canal is the last part of the gastrointestinal tract, spanning from the rectum to the anus. It’s surrounded by the internal anal sphincter in its upper part and by the external anal sphincter in its lower part. The surgical procedure targets key landmarks inside the canal. The blood supply to the anal canal comes from the superior and inferior rectal arteries, depending on the section of the canal. Lymphatic drainage, which is part of the immune system, also varies depending on the part of the canal.
The nerves controlling the actions of the anal canal have both automatic and voluntary control. The pudendal nerve, which supplies the lower part of the canal below the so-called pectinate line, makes this area sensitive to pain, temperature, and touch. The anal sphincter complex, responsible for maintaining continence (the ability to control bowel movements), includes the internal and external anal sphincters. The internal one provides constant pressure, while the external one can be voluntarily controlled, helping prevent stool leakage when the internal sphincter relaxes or when there’s a sudden increase in abdominal pressure such as during coughing or lifting.
The pelvic floor is a set of muscles supporting the pelvic organs including the rectum and anal canal. It helps maintain continence and support the organs inside the abdomen. In the surgery, this floor is approached and divided to allow removal of the lower part of the rectum and anal canal.
The pelvic area is densely interconnected with nerves that are closely related to the rectum and anal canal. These nerves control various functions like bowel movement and bladder control. During the surgery, care is taken to preserve these nerves while completely removing cancerous tissue to effectively treat the cancer and avoid complications.
Why do People Need Abdominoperineal Resection
Abdominoperineal Resection (APR) is a type of surgery that’s recommended in various conditions. Here’s a simplified list of some illnesses where this surgery might be necessary:
1. Anal Cancer: If you have this type of cancer and it keeps coming back or doesn’t get better with chemotherapy or radiation therapy, an APR might be an option.
2. Rectal Cancer: APR might be needed if:
* The cancer is very low in your rectum and touching or invading the muscles that control your anus or surrounding muscles.
* You require a very low rectal surgery but the muscles aren’t strong enough to work properly afterward.
* The cancer is located 4 cm to 6 cm from the anal opening, and trying to save the muscle would leave behind some cancer cells or result in poor functioning after the surgery.
3. Non-cancer conditions: APR can be a solution for certain non-cancer conditions, such as:
* Anorectal fistulae, which are abnormal connections between the rectum and skin that won’t get better with less invasive treatments or therapies.
* Inflammatory bowel diseases like Ulcerative Colitis or Crohn’s disease, especially if there’s significant disease in the anus or rectum that don’t get better after less invasive treatments or therapies.
* Inability to control bowel movements that can’t be tackled with less invasive treatments.
* Serious damage to the anus due to an accident or injury.
When a Person Should Avoid Abdominoperineal Resection
APR surgery might not be possible for some patients if they are not healthy enough to handle general anesthesia, which is a type of medicine that makes you unconscious and insensible to pain during operations. Other conditions could also make the surgery riskier. For instance:
1. If a person has diabetes that isn’t well-managed, it could cause complications after the surgery.
2. Obesity, especially severe obesity, might increase the risks of problems after the surgery.
3. If a patient is extremely weak or frail, they may not recover well from the surgery.
4. If a person’s immune system isn’t working well (a condition called immunosuppression) it can make it harder for them to recover after the surgery.
Equipment used for Abdominoperineal Resection
What tools your doctor needs to perform an APR (abdominoperineal resection), a surgery done to remove the lower part of the colon and rectum, depends on whether the operation is done using traditional open surgery or a less invasive method. Regardless of how the surgery is done, a movable operating table is needed. This table must be able to adjust for positions necessary during surgery, such as having the patient’s legs raised (lithotomy) and bending the body forward (prone jack-knife).
Open, laparoscopic (a small tube with a camera is used), and robotic procedures all need the usual equipment used for major surgeries in the stomach area. There are also additional tools that should be on hand for an APR. These include lighted pelvic retractors (tools like St Mark retractors that help keep the area being operated on open), perineal retractors (similar tools like Lone Star retractors are used for the area between the genitals and the anus), and energy devices (tools that use heat to cut or coagulate tissue).
Who is needed to perform Abdominoperineal Resection?
An Abdominoperineal Resection (APR), a surgery usually used for rectal cancer, involves a team of medical professionals like the surgeon, an assistant, an anesthesiologist who administers anesthesia (medication to make you sleep during surgery), and a surgical technician, or a nurse who assists in the surgery. In some cases, urologic or gynecologic assistance might be required. This might be the case if the surgery becomes more complex, or if a stent (a small tube to help with fluid flow) needs to be put into the ureters (tubes that carry urine from your kidneys to your bladder before surgery).
Before the surgery, you’ll be given information and counselling about a special opening that’ll be made in your body, called a stoma. This is necessary for the surgery, but it’s very important that its location is carefully chosen, so it’s most convenient and comfortable for you.
Counseling before the operation will help you understand what living with a stoma will be like, including any emotional effects, and practical things you need to take into account. An enterostomal nurse therapist, a nurse with special training about stomas, is key in this process. These nurses will help you understand what to expect before and after the surgery, and on how to take care of your stoma. This way, you can have a good quality of life after the surgery.
Preparing for Abdominoperineal Resection
Before patients go through a major belly operation, such as a colorectal surgery, doctors will perform a pre-surgery check-up, tailored to fit the needs of each individual. The doctor will study any pre-operation scans, like a rectal MRI (a detailed picture of the rectum, taken with a large magnet), especially in cases of cancer. Patients will also meet with a specialized nurse, who will discuss the details of the upcoming surgery, insulin pump placement, and answer any questions or concerns.
Patients going for colorectal surgery typically follow a care plan known as ERAS (Enhanced Recovery After Surgery). This plan involves steps like cleaning the bowel and using antibiotics, drinking clear liquids high in carbohydrates up to 2 hours before surgery, controlling pain with multiple non-opioid medications, regulating body temperature during and before the operation, controlling fluids for balanced hydration, and using medication like alvimopan to block opioid receptors.
Just before the surgery, there are also specific steps to follow:
Patients are placed in a specific position known as the lithotomy position, where they lay on their back with legs raised and spread apart on stirrups. This gives the doctor easy access during the surgery. Sometimes, doctors may prefer the patient to be in a prone jack-knife position, where they lay on their stomach with the knees bent and spread apart. If this position is preferred, the patient will be moved into it, following the stomach portion of the surgery.
Doctors also give broad-spectrum antibiotics, which kills many different types of bacteria, within 30 minutes of making the first cut. For cases where there might be a risk of harming the ureters (tubes that carry urine from the kidneys to the bladder), stents (tiny tubes) may be placed in the ureters prior to surgery. These do not prevent injuries but can help find and fix them early if they occur. A Foley catheter (a tube that drains urine from the bladder) is then placed in all cases.
Finally, the doctor will perform a digital rectal exam. This is a manual test where the doctor uses a gloved and lubricated finger to check for any abnormalities. For women, the vagina is included in the surgical area in case the doctor needs to move the uterus or feel the back wall of the vagina during the surgery.
How is Abdominoperineal Resection performed
There are different ways doctors can perform an abdominoperineal resection (APR), a surgery where the anus, rectum, and the last part of the sigmoid colon are removed. APR is commonly used to treat rectal cancer. It can involve open surgery, laparoscopic surgery (using small cuts and a camera), or robotic-assisted surgery. This process has two main stages which can be done at the same time or one after the other.
Abdominal Operation:
To start off, the doctor needs to get inside the belly. They might do this with a cut down the middle of your lower belly, or by using up to six small tubes (ports) for laparoscopic or robotic surgeries. Good lighting is crucial for open surgery, while a certain posture and pulling back on the rectum can improve visibility in less invasive procedures.
Once inside the belly, the doctor will check for any signs of the cancer having spread. Then, they’ll move the small bowel to the upper belly areas, and any redundant sigmoid colon is reduced from the pelvis. The doctor then begins to separate the sigmoid colon from the abdominal cavity. During this, they have to ensure the left ureter and gonadal vessels are identified and preserved – these are important structures in the body that need to be left intact. A blood vessel called the superior rectal or inferior mesenteric artery is tied off. Mobilization of the splenic flexure is usually unnecessary.
Next comes total mesorectal excision, which involves taking out all the lymph nodes and fats surrounding the rectum. Care must be taken to avoid damaging nerves or causing intense bleeding. The doctor then completes mobilization of the rectum, leaving the mesorectum attached to the levator muscles, which help in bowel movement. Then, they transect the colon with a stapling device, leaving enough mobility to prevent tightness at the where the stoma, an opening created in the belly to divert stool, will be placed.
If feasible, the doctor can create an omental flap – a fatty layer in your belly, which can improve wound healing. Then, a place is created on the abdominal wall so that the colon (with tumor) can pass through. If the operation is being performed with you laying face down (prone), the belly wound is usually stitched up and the stoma is created at this stage. Communication between the inside of your body and the outside world through a stoma or opening made in the abdomen.
Perineal Operation:
Next, the procedure moves on to the perineal or hind area. Some of the benefits of positioning you face down includes superior exposure and visualization, especially for tumors towards the front. The part around the anus is exposed and carefully sewed up to stop fecal leakage. A cut is then made around the anus. Then comes very intricate and careful dissection of the anorectal area, ensuring that critical structures are spared any damage.
Then the doctor separates the rectum and disconnected sigmoid colon and takes them out through the perineal cut. It’s then time to confirm that bleeding has stopped, and a surgical drain is placed. If an omental flap was created, it is brought down and stitched into the perineal wound. The pelvic floor is then stitched up in layers to close it. In patients with large perineal wounds or significant risk factors for wound dehiscence—such as neoadjuvant radiation therapy, malnutrition, chronic steroid use, obesity, or diabetes—skin cover with flap closure might be needed.
The surgery can have some variations, one of them being the extrasphincteric resection. In this case, the dissection during the perineal stage of the operation is immediately external to the sphincter muscles, through the fat tissues. This would not involve cutting the levator muscle close to its point of attachment to the pelvic sidewall.
Possible Complications of Abdominoperineal Resection
After abdominal and perineal surgical procedures like APR, various complications might occur. These could include:
* Infections at the operation site.
* Pockets of pus (abscesses) in the belly.
* Slowed or blocked bowel movements after surgery.
* Injuries to the tube that carries urine from the kidneys to the bladder (ureter).
* Problems with sexual function or urination.
* Issues related to the surgical opening (or stoma) created on the body to remove waste.
One good aspect of APR is that it doesn’t use a procedure known as anastomosis, which is used to connect two parts of the intestines. So, patients won’t face complications from that procedure.
However, there are couple of complications that surgeons must consider while performing APR:
* Wound dehiscence (when a wound reopens):
APR involves removing components of the anal sphincter, creating a weak spot especially in those patients with smoking habits, diabetes, obesity, history of radiation therapy, or lack of appropriate nutrients. Such complications are often seen in patients who are undergoing surgery for anal cancer or inflammatory bowel disorders compared to rectal cancer. The opening wound might show signs of clear or salmon-colored discharge. Regular checks to ensure the deeper tissues aren’t compromised as wound reopening often comes with infections. Normal dehiscence can be looked after with local wound care and monitoring, using dressings that create negative pressure. If the case is severe, a surgical procedure to close the wound using a tissue transfer might be needed. In critical cases where abdominal organs protrude, emergency surgery is needed.
* Perineal wound infections:
Post APR, these types of infections are common, even more so in patients having inflammatory bowel disease. Superficial infections can be handled with antibiotics targeting skin and soft tissue organisms. However, deeper infections associated with abscesses or collection of fluid underneath the skin require a more aggressive treatment approach including draining the wound or removing dead tissue, along with medication. Large abscesses, over 5 cm, often require surgical intervention as simple drainage wouldn’t help.
* Urethral injury:
The urethra, a tube that carries urine out of the body, is pretty close to the anal canal, so it’s susceptible to damage during APR. Careful steps performed during surgery and feeling the catheter (a soft tube inserted to empty bladder) to know the urethra’s location is critical to prevent injuries.
* Nerve injuries:
These can occur during different stages of the operation, most commonly affecting both the sympathetic and parasympathetic nerves, which control involuntary body functions like heart rate and digestion. Symptoms might include problems with ejaculation, erectile dysfunction, dryness in vagina, and pain during intercourse.
What Else Should I Know About Abdominoperineal Resection?
APR, or abdominoperineal resection, is a major type of surgery mainly used to treat cancers in the lower part of the rectum (the end of the intestine where stool is held) and anus (the opening at the end of the digestive tract). This process might also be used for non-cancerous diseases in this area. During this operation, the doctor removes several parts of your body including the anus, the anal canal along with the surrounding muscles that control bowel movements, and the rectum. Then, they create a permanent opening in your abdomen, known as a colostomy, for waste to exit the body into a bag.
Thanks to advances in medicine, less invasive methods like radiation therapy are reducing the need for this type of surgery. That being said, APR still remains a critical tool for surgeons when treating certain rectal and anal pathologies.
It’s very important to select the right patient for this operation, and whenever possible, doctors will opt for techniques that spare the sphincter muscles to prevent a permanent colostomy. If you do need to undergo APR, counseling and emotional support will be an essential part of your care. This will help you adjust to the changes in lifestyle brought about by living with a permanent colostomy.
