Gastrointestinal Malignancy Flashcards
What is a hemicolectomy?
“Hemi-“, “-ectomy” - A piece of the colon is removed, along with its accoutrements.
It follows the anatomical lines of the bowel:
Piece of colon removed
Associated lymphatics are removed
Artery to that piece of colon is removed
Venous drainage to that piece of colon is removed
Autonomic nerves are PRESERVED
What is an anterior resection?
SIGMOID/RECTUM: An anterior resection is like a left hemicolectomy + temporary ileostomy (opening in to the ileum). (Removal includes: superior/middle rectal arteries/veins and pararectal lymph nodes)
Indications - Low sigmoid or high rectal cancers
MOA: It is performed via the anterior abdominal wall and is sometimes to remove rectum as well as colon
The anastamosis between the ends of the bowel is often left to recover by adding a loop ileostomy:
A“defunctioning stoma” at the ileum, which prevents the large bowel functioning, and avoids stress and risk of infection in the resected bowel during its healing.
Autonomic nerves are PRESERVED
What is Hartmann’s procedure?
EMERGENCY: Like a left hemicolectomy + (potentially) temporary colostomy (opening in to the colon).
Indications - bowel obstruction, perforation or palliation.
An emergency left-sided procedure: When a piece of bowel must be removed but it must not be reattached.
MOA:Cut out a malignancy in the sigmoid/descending colon, make a stoma in the abdominal wall, and extrude the end of the proximal colon out of the abdomen.
Indications - colon malignancy with peritoneal contamination or colon malignancy with haemodynamic instability (blood supply would be compromised if anastamosed)
The rectum is closed at its proximal end to form a “rectal stump” - which can be reattached to the end colostomy later.
The extruded colon is called an “end colostomy” - the colon end forms the stoma.
Autonomic nerves are PRESERVED
What is an abdomino-perineal resection?
RECTUM: This is an extensive left hemicolectomy + permanent colostomy (Removal includes: removal of arteries/veins etc of left colon and superior/middle/inferior rectal arteries/veins and pararectal/internal iliac lymph nodes)
Indications - low rectal cancers
Key difference: If there will not be enough distal rectum left for anastamosis after this colectomy, so the rectum and anus are both entirely removed, and a permanent end colostomy is formed from the distal end of the colon.
MOA: The colon is removed via the abdomen as per usual. The rectum/anus is removed via a perineal incision.
What are the four types of colostomy?
Ascending colostomy
Transverse colostomy
Descending colostomy
Sigmoid colostomy
What is a loop ileostomy?
A loop of ileum is pulled out of an incision, and opened and stitched to the skin to form a stoma. The ileum remains attached to the colon.
Note: an incision isn’t a stoma because it isn’t a permanent opening, it will heal and seal.
Ileostomies are indicated for in healing post-surgery, relief of inflammation in IBD (prevent chyme getting there) or for more complex surgery to be carried out on the colon or anus.
Looks like:
Spouted (- more sticking out, not flush with skin)
Continuous effluence leak (- always exuding fluid)
Contents is liquid
Found most commonly in the right iliac fossa
What is an end ileostomy?
The ileum is separated from the colon and brought out of the abdomen via an incision to form a stoma.
Ileostomies are indicated for in healing post-surgery, relief of inflammation in IBD (prevent chyme getting there) or for more complex surgery to be carried out on the colon or anus.
Found most commonly in the right iliac fossa.
What is an ileostomy-anal pouch?
An internal pouch that bypasses the colon and connects the ileum to the anus, so normal excretion by the anus occurs.
What are the complications of an ileostomy?
Bowel obstruction
Vitamin B12 deficiency - if the ileum is removed/damaged
Stoma infection/inflammation
What are the indications for a colostomy?
Bowel cancer
Chron’s disease
Diverticulitis
Anal cancer
Vaginal/cervical cancer
Bowel incontinence
Hirschsprung’s disease
What are the two main types of colostomy?
- Loop colostomy - remains attached to rectum, a loop is pulled out of the incision and accessed.
- End colostomy - the colon is detached from from the distal colon/rectum etc and this end is extruded from an incision. This is the more common type of colostomy
The incision is most often found in the left iliac fossa.
What is a right hemicolectomy?
Removal of part of the colon to the right of the midline, along with ileocolic/right colic arteries/veins and superior mesenteric lymph nodes.
Indications - caecal/ascending/proximal transverse colon cancers
MOA;
Right hemicolectomy:
The caecum and part of the ascending-transverse colon is removed. The ileum is then connected to the end of the transverse colon
5cm of healthy bowel distal to the disease also removed.
Autonomic nerves are PRESERVED
What is a left hemicolectomy?
Part of the distal transverse/descending colon is removed, along with the right colic/middle colic/left colic arterie(s), middle/left colic vein(s)
Indications - distal transverse/descending colon cancer
MOA;
5cm of healthy bowel on either side of the disease is also removed. The descending colon and the remains of the sigmoid colon will be reattached.
Indication - diverticular disease or colorectal cancer
Autonomic nerves are PRESERVED
How might we summarise the surgical procedures of the colon and rectum, proximal to distal?
Right hemicolectomy (- ascending to proximal transverse) Left hemicolectomy (- distal transverse to descending) Anterior resection (- sigmoid to proximal >8cm rectum) Abdomino-perineal resection (- distal <8cm rectum)
Or in an emergency: Hartmann’s procedure.
Al of these can be done as open or laparoscopic surgery.
What is the typical management pathway for CRC?
In short: Primarily surgical intervention, chemotherapy addition depends on staging. Most patients are elderly (CRC - old onset) so they are complicated patients.
- MDT meeting discussion
- Pre-op: FBC, U+E, Cross matching, clotting (surgery means bleeding) - fitness testing for elderly patients - stoma care education
- Pre-op radiotherapy If Duke’s 3/4: to shrink tumour and make it operable
Duke’s 3 = short course
Duke’s 4 = long course +/- chemotherapy - Surgery within 1-2 months of diagnosis
- Surgery is a segmental resection: get rid of diseased bowel but also remove that segment’s lymph nodes, artery and venous drainage - a wide excision in order to ensure a good oncological outcome
- Procedure is often open surgery but is moving towards more laparoscopic
- Adjuvant chemotherapy if Duke stage 3/4 - i.e. nodal involvement
Long course for Duke’s 4 = 6/12 with 5-fluorouracil - Post-Op: HDU If high risk - early cardiorespiratory problems - sepsis problems - enhanced recovery
- Follow up for five years: CT (possibly PET/MRI)
What is a stoma?
A hole made in to any hollow organ.
What are the criteria for a local excision instead of hemicolectomy?
A local excision is for when the cancer is:
- Superficial - T1 only in the mucosa
- Small - less than 3cm diameter
- Well differentiated - tissue looks like the normal tissue histopathologically
Risk: miss some cancerous cells and see recurrence
Benefits: avoid the dangers of a large colectomy procedure
