hi there this video is explaining how surgeons approach rectal cancer rectal
cancer treatment is very different from colon cancer I have another video
explaining colon cancer surgery that you might want to check out let's review the
anatomy of the intestinal tract when you eat food it goes through the esophagus
and into the stomach then into the small intestine for many feet then the small
intestine empties into the colon in the right lower abdomen the colon runs up
the right side of the abdomen across the top then down the left side of the
abdomen the last bit of colon snakes around and is called the sigmoid
colon the turn of the colon and the right upper abdomen by the liver is
called the hepatic flexure and the turn on the left upper abdomen near the
spleen is called the splenic flexure the abdominal organs including the colon are
contained within the sac of the abdomen called the peritoneal sac the colon then
exits the abdominal sac and enters the soft tissue of the pelvis once the colon
leaves the sac of the abdominal organs it becomes surrounded by fat and
eventually the muscles that control the anal canal once it exits the peritoneal
sac and is surrounded by fat this is then considered rectum the rectum is
usually around 15 centimeters from the anal opening although the distance
varies on how tall a person is the rectum is split into the upper rectum
which is 10 to 15 centimeters from the anal opening the middle rectum which is
5 to 10 centimeters from the anal opening and the lower rectum which is
the lowest part just above the anus rectal cancer usually presents with
blood in the stool that is bright red since it is so close to the anus
sometimes people have a hard time passing the stool or the stool is very
thin because the lumen is narrow from the cancer a doctor usually confirms the
diagnosis of rectal cancer by doing a colonoscopy with the camera and taking a
biopsy of the mass almost all rectal cancer is the type called adenocarcinoma
once you are diagnosed with rectal cancer we usually do a CT scan of the
chest and the belly to be sure that cancer has not spread common places to
spread are the lungs and the liver we also usually like to do specific
pictures of the rectum with either an MRI which is a tube you lay in for 15 or
30 minutes or sometimes an ultrasound which is done directly through the
inside of the rectum the surgery for rectal cancer is the most complicated of
the colon and rectal cancer surgeries this is because you have to remove the
rectum from the fat and organs in the pelvis the other organs such as the
uterus and vagina and women or the bladder and the prostate and men are
very close to the rectum the ureter tubes drain urine from the kidney to the
bladder and these are also close to the end of the colon and the rectum for
rectal cancer surgery we want to remove at least 12 lymph nodes rectal cancer
drains to lymph nodes all the way up by the sigmoid colon the lymph nodes are
intertwined with a blood vessel supplying the rectum and lower sigmoid
colon in order to remove the 12 lymph nodes we usually have to remove about
one foot or more of the end of the sigmoid and rectum to at least two
centimeters below the rectal cancer in order for the remaining colon to reach
into the pelvis to reconnect to the remaining rectum we have to release
attachments at the splenic flexure and the left descending colon the colon is
reattached to the stump of rectum left with either a stapling device or by
sewing by hand this surgery is called a low anterior resection or abbreviated as
LAR lastly if the patient has had radiation before surgery
this can make healing worse so we usually do not trust the reconnection of
the colon and the rectum not to leak as it is healing commonly after radiation
for rectal cancer when we remove the rectum and reconnect the colon to the
remaining stump of rectum we recommend diverting stool away from the colon
while it is healing this is done with a loop of small bowel turned into an
ostomy called a loop ileostomy the packaged surgery is lar with diverting
ileostomy the stool comes out of the end of the small intestine into a bag
after several weeks or months a surgery can be done to reconnect the small
intestine and stool will go back through the colon and out from the now healed
reconnected colon and rectum we wait a minimum of several weeks for two reasons
one is to allow time for the reconnected colon and rectum to heal and also to
allow the scar tissue around the ileostomy to soften up for large rectal
cancer or rectal cancer that is very close to the anus sometimes a surgeon
cannot reconnect the colon to any rectum that is left if this is the case then we
may have to remove the entire rectum along with the anus and so the space
where the anus was shut completely this obviously requires a colostomy which is
brought up to the skin from the end of the remaining colon and this is a
permanent colostomy for the rest of your life this surgery is called an abdomino-
perineal resection abbreviated as APR we try not to have to do the surgery and
if we can get even one or two centimetres below a rectal cancer and it
will leave enough anal muscles to allow for continence of stool we will try to
avoid the APR surgery and do the LAR plus-minus ileostomy surgery okay let's
talk about treatments other than surgery because these are very important in
rectal cancer adenocarcinoma of the colon is usually removed with surgery
then chemotherapy is given if needed radiation is rarely used in colon cancer
one major difference between colon and rectal cancer is that rectal cancer
frequently uses radiation let's magnify a portion of the rectum the wall of the
rectum has layers and the middle layer is muscle for early rectal cancer that
has not invaded through the muscle layer in the wall you may just have surgery
and not get any chemotherapy or radiation but if the cancer is growing
deep into the wall of the rectum through this muscle layer or if it looks like
it's already in lymph nodes on x-rays then we will commonly use radiation
before surgery radiation helps shrink the tumor making surgery easier and it
can decrease the regrowth rate of tumor if you are getting radiation for
rectal cancer you will frequently be given a very light version of
chemotherapy that makes the radiation work better true chemotherapy with
multiple types of chemotherapy at once is not given at the same time as
radiation as this can cause too many side effects radiation with light chemo
last five to six weeks after radiation we typically do surgery next then
chemotherapy if needed comes last so a quick recap early rectal cancer not
growing through the muscle of the wall of the rectum gets surgery and no other
treatment deeper rectal cancer growing through the muscle layer or into lymph
nodes gets radiation with light chemotherapy then surgery then
chemotherapy after some times if a cancer is very small and early and has
not grown into the wall of the muscle of the rectum and is in the lower third of
the rectum we may be able to remove it from the anal opening just by taking out
a part of the wall of the rectum and stitching it shut this is called a trans
anal excision this is only for very small very early rectal cancer it is
sparingly used since we cannot check lymph nodes with this technique cancer
of the anal canal itself is treated differently the lining of the colon and
the rectum makes adenocarcinoma type of cancer the lining of the anal canal is a
different type of cell and it makes squamous cell cancer anal canal cancer
is usually treated with chemotherapy and radiation and usually does not need
surgery I hope this helps remember to talk to your doctor about screening for
colon and rectal cancer and don't forget to check out my other videos on my
channel that may help you and don't forget to subscribe so you don't miss
out on anything new take care