Low Anterior Resection

What is a low anterior resection (LAR)?

A low anterior resection (LAR) is a type of proctectomy — surgery to remove part or all of your rectum. It’s a treatment for rectal cancer. “Low anterior” means the surgery goes through your lower front side.

Your rectum is a segment of your large intestine. It’s at the lower end, about six inches long. It connects your colon above it with your anus below it. Your rectum stores poop until you're ready to release it.

During this surgery, your surgeon removes the part of your rectum that has cancer in it, along with some healthy tissue around it. Sometimes, this means removing part of your colon as well (proctocolectomy).

With this surgery, your anus stays intact. After removing the cancerous section of your intestine, your surgeon reconnects the remaining parts of your bowel so it can still work as it did before.

This is also called:

• Restorative proctectomy (because it lets your bowel be reconnected like before)
• Sphincter-sparing surgery (because it keeps the sphincter muscles that control your bowels)

LAR surgery is an option to treat rectal cancer only under certain conditions. Importantly, the tumor has to be high enough in your rectum that your surgeon can safely remove it without damaging your anus.

What happens before low anterior resection surgery?

Whether and when you have LAR surgery depends on the nature of your tumor: where it is, how big it is, and if or how much it has spread. Your healthcare team will do some tests to decide. These may include:

• Blood tests: Blood tests provide many indicators of health and help healthcare providers ensure you’re in good enough condition for surgery. They can also show signs of cancer spreading.
• Flexible sigmoidoscopy: This is a shorter version of a colonoscopy that focuses on the end portion of your colon. Your provider will examine the tumor and may take a biopsy.
• Imaging tests: You may have a CT scan of your upper body to look for signs of cancer spreading to your abdominal organs. You may have an MRI of your lower body to examine your bowel.

Based on the results, your healthcare team will decide if a low anterior resection is right for you.

They’ll also discuss whether you should:

• Have other cancer treatments first. Treatments like radiation therapy or chemotherapy can help shrink the tumor before surgery. You might also have these treatments after surgery.
• Have minimally invasive surgery or open surgery. Most of the time, surgeons perform lower anterior resection by laparoscopic surgery. But in some cases, open surgery may be safer.
• Have a temporary ostomy. In some cases, your surgeon will create a temporary ostomy to divert your poop away from your rectum while it heals. They can reverse it later.

Your healthcare team will fill you in on these plans when they schedule your procedure. When you know what to expect, you’ll be able to plan for time off and the help you’ll need at home.

How should I prepare for my procedure?

Your team will give you instructions to follow in the days leading up to the procedure, including:

• Which medications to start or stop.
• What you can and can’t drink.
• How to clear out your bowels with an enema or bowel prep.

What happens during a low anterior resection?

Prep

When you arrive for your operation, you’ll lie on your back on the operating table. A provider will tilt the table so your head is below your hips (Trendelenburg position). This helps your surgeon access your organs.

Your team will place an IV in your vein to give you general anesthesia. You’ll also have a breathing tube to keep your airways open, a tube to drain your stomach fluids and another tube to drain your pee.

Approach

• In open surgery, your surgeon makes one long cut (incision) to open your abdomen.
• In laparoscopic surgery, your surgeon will make a small “keyhole” incision in your abdomen and place an instrument with a tiny camera (laparoscope). The camera shows the inside of your belly on a screen. They’ll make four or five more small cuts to insert tools and operate.

Steps

To perform your low anterior resection, your surgeon will:

1. Remove the tumor from your rectum, along with a margin of healthy tissue around it. This is to make sure no cancer remains left behind. They may also remove nearby lymph nodes or other tissue to test for cancer spread.
2. Free up your remaining healthy large bowel so it can reach your remaining rectum or anus.
3. Reconnect the remaining sections of your large bowel. This is called surgical anastomosis.

Ostomy

Your surgeon may create a temporary ostomy to help your bowel heal. This diverts stool (poop) away from the place where your bowel was reconnected, reducing the risk of leakage and infection.

To do this, your surgeon will cut open your intestine somewhere above the surgical site and bring the open part to the surface of your skin. Here, they’ll create a new opening in your skin, called a stoma.

Stool will now leave your body through the stoma and collect into an ostomy bag that you’ll wear on your belly. You’ll empty the bag several times during the day.

An ostomy is called a colostomy when it divides your colon, and an ileostomy when it divides your small intestine. If it’s meant to be temporary, it’s called a loop ileostomy or loop colostomy.

What are the potential risks and complications of low anterior resection?

Your surgical team will talk with you about the potential risks and complications of surgery in advance, including:

• Bleeding
• Infection
• Leaking where your bowel was reconnected (anastomotic leak)
• Nerve damage that affects your bladder control or sexual function

Most of these problems are short term and treatable. But sometimes, nerve damage can be lasting.

What happens after LAR surgery?

After surgery, you’ll stay in the hospital for a few days to recover. You’ll receive pain medications and antibiotics to prevent infections. You’ll start with a liquid diet until you feel ready for solid food.

You may have a tube (catheter) in your bladder to drain your urine. This is because surgery near your rectum can temporarily affect the nerves that control your bladder.

Your healthcare team will help you get up and move a little each day. If you have an ostomy, a wound ostomy continence nurse (WOCN) will teach you how it works and how to care for it at home.

You’ll be ready to go home when:

• Your bowels and bladder are working well.
• You can move around comfortably on your own.
• You’re eating solid foods.
• You can tolerate pain medicine by mouth.

How long is the recovery from a low anterior resection?

You’ll spend at least a few weeks recovering at home. You may want to have some help with meal preparation, housework or childcare during this time. Most people can return to work after a month.

You should be able to comfortably transition from opioid pain medications to over-the-counter pain relievers after the first few days. If your pain isn’t improving by this time, contact your provider.

After a few weeks, you’ll see your care team to check on your recovery and talk about next steps. You may start more cancer treatment then.

If you have a temporary ostomy, you can talk to your surgeon about reversing it after your cancer treatment is complete. This is to ensure your body is strong enough to recover.

When should I call my healthcare provider?

During your recovery, call your provider if:

• Your pain gets worse or doesn’t go away.
• Your stoma looks red, swollen or infected.
• You have a fever or a swollen belly.
• Your ostomy is draining too much and you’re getting dehydrated.

What are the advantages and disadvantages of low anterior resection surgery?

When rectal cancer is still in the early stages, surgery is your best hope of removing it completely from your body. A low anterior resection is just one of several surgical procedures that treat rectal cancer.

The main benefit of LAR over other procedures for rectal cancer is that it leaves your anus intact. Unlike abdominal perineal resection, LAR allows you to live without a permanent ostomy.

This might sound ideal — but there’s a tradeoff. Cutting your rectum changes the way that you can control how you go to the bathroom. After surgery, your bowel and anus may not work as well as they used to.

After your surgery, you may have frequent and urgent bowel movements that are difficult to control, or other pooping problems. This is called low anterior resection syndrome (LARS).

These symptoms may get better slowly. However, in many cases, your bowel function will never be the same as it was before surgery. While LAR surgery can save your life, LARS may lower your quality of life.