There are different types of surgery for bowel cancer. The operation that is most suitable for you depends on where your cancer is, the type and size of cancer and whether your cancer has spread to other parts of your body.
For a small early stage cancer, your surgeon might just remove the cancer from the bowel lining, along with a border of healthy tissue. This is called a local resection.
If your cancer is larger, your surgeon might remove the part of the bowel where the cancer is, and join the two ends back together. This is called a colectomy. They might also remove the lymph nodes near to the bowel in case the cancer has spread to the nodes.
To give the bowel time to heal, the surgeon might make a temporary ileostomy or colostomy. This is an opening from the bowel that leads to the surface of the abdomen and is called a stoma. Waste matter from the bowel collects into a special bag over the opening. You have another operation to repair the stoma after a few months (a stoma reversal).
The surgeon might have to make a permanent stoma if a lot of your bowel is removed. But most people don't need a permanent stoma.
Open surgery is where your surgeon makes one long cut down your abdomen to remove the cancer.
Keyhole (laparoscopic) surgery is where your surgeon makes several small cuts in your abdomen. A long tube with a light and camera is passed through one of the holes. Surgical instruments are put into the other holes and are used to remove the cancer.
Keyhole surgery can take longer than open surgery, but generally people recover quicker.
Your surgeon removes the cancer and a border of healthy tissue (margin) around the cancer. The tissue goes to the laboratory for tests.
A specialist doctor called a pathologist looks at the cancer cells under the microscope, to see how abnormal they are. If the cells look very abnormal (high grade), your surgeon may decide you need a second operation. This removes tissue that could contain cancer cells and lowers the chance of your cancer coming back.
The type of operation you have depends on where your tumour is in the large bowel (colon). The surgeon removes the part of the colon containing the tumour. This is called a colectomy. How much your surgeon takes away depends on the exact position and size of the cancer.
Removing the left side of the colon is called a left hemi colectomy.
After your surgeon removes your cancer, they join the ends of the bowel back together. The join is called an anastamosis. Sometimes to give the bowel time to heal, the surgeon brings the end of the bowel out as an opening on your abdomen called a stoma. If the small bowel is bought out onto the abdominal wall it is called an ileostomy. If the large bowel is bought out it is called a colostomy.
The stoma is usually temporary and the ends of the bowel are joined back together in another operation a few months later. This is called a stoma reversal. In the meantime you wear a colostomy or ileostomy bag over the opening of the bowel, to collect your poo.
If you have a large area of bowel removed, or are in poor health, you may need to have a permanent colostomy or ileostomy. Your surgeon will avoid this if at all possible. Sometimes your surgeon can't tell if you will need a permemant stoma until during the operation. They may not know how big the cancer is, or how much of the bowel it affects. Your surgeon will explain this to you before the operation.
Surgery to remove the whole of the large bowel (colon) is called a total colectomy. The surgeon brings the end of the small bowel to the surface of the abdomen to make an ileostomy. Sometimes it is possible for the small bowel to be joined to the lower part of the bowel (the rectum).
Sometimes bowel cancer can cause a blockage. This is called bowel obstruction. If this happens you will need an operation straight away. Your surgeon may put a tube called a stent into the bowel. This holds the bowel open allowing it to work properly again. Or your surgeon may remove your tumour from the bowel.
You may have radiotherapy, or chemotherapy and radiotherapy together (chemoradiation) to shrink the cancer before surgery and make it easier to remove. This also lowers the chance of the cancer coming back in the back passage (rectum) after surgery.
If you have a small early stage cancer, your surgeon may be able to remove it in an operation called a local resection (trans anal resection). The surgeon puts an endoscope (a flexible tube with a light) in through your back passage and removes the cancer from the wall of the rectum. This is called trans anal endoscopic microsurgery (TEM).
Total mesorectal excision
During most operations for rectal cancer, the surgeon removes the cancer with a border (margin) of tissue from around it. The cells in the surrounding tissue (margin) are tested for cancer cells. If there are no cancer cells, this is called a clear margin. They also remove fatty tissue around the bowel and a sheet of tissue called the mesorectum.
The mesorectum is a sheet of tissue surrounding the intestine, bowel, and rectum. It contains blood vessels and lymph nodes. It is possible that cancer cells may have spread to the mesorectum.
Complete removal of the mesorectum, along with a border (margin) of tissue around the cancer, lowers the risk of the cancer coming back. This operation is called total mesorectal excision (TME). There are different types of total mesorectal excision depending on where the cancer is in your rectum, and how big it is.
Cancer high in the back passage (rectum)
Your surgeon will remove the cancer and a small border (margin) of tissue around it. They attach the end of the colon to the remaining part of the rectum. The mesorectum is removed to 5cm below the bottom edge of the tumour. Leaving some of the mesorectum in place, reduces the risk of a leaking bowel after surgery. This operation is called an anterior resection.
Cancer in the middle of your back passage (rectum)
Your surgeon removes most of your back passage (rectum) and attaches the bowel (colon) to your anus. This is called a colo-anal anastamosis. Sometimes the surgeon can make a small pouch by folding back a small section of colon or by enlarging a section of the bowel (colon). This small pouch works like the rectum did before surgery.
To allow time for the area to heal, your surgeon brings the end of the bowel out as an opening on your abdomen called a stoma. This may be for about 8 weeks. You then have a second operation to close the stoma. This is called a stoma reversal. Sometimes with a colo-anal anastamosis you may need a permenant stoma.
Cancer low in the back passage (rectum)
Your surgeon may not be able to leave enough of the rectum behind for it to work properly. Your surgeon removes the anus and rectum completely. This is called an abdomino-perineal resection (AP resection). They will make a permenant colostomy opening on your abdomen. After this surgery you will have a wound on your abdomen, and another wound where your anus has been closed.
The surgeon makes one large cut in your abdomen to remove your cancer. The cut may be from the bottom of your breastbone (sternum) down to the level of your hip bones.
Keyhole (laparoscopic) surgery
The surgeon makes several small cuts in your abdomen. A small tube with a light on the end (a laparoscope) goes into one of the holes. Surgical instruments go through the other holes and are used to remove the cancer. Keyhole surgery may take longer than open surgery, but usually recovery is quicker. Sometimes during keyhole surgery the surgeon has to switch to open surgery.
Robotic assisted laparoscopy
Some surgeons use a robotic system to help with keyhole surgery. The surgeon sits slightly away from you and can see the operation on a magnified screen. The robotic machine is next to you. The machine has 4 arms. One arm holds the camera, and the others hold the surgical instruments. The surgeon controls the arms of the machine to remove the cancer.
Robotic assisted laparoscopic surgery might help to lower the risk of your surgeon needing to switch to open surgery, lower the risk of complications during and after surgery and shorten your time in hospital.