Colorectal Flashcards
What are causes of small bowel obsturction
HAT
Hernia
Adhesion
Tumour
What are causes of large bowel obstruction
CVS
Cancer
Volvulus
Strictures (from diverticulitis)=
What are big risks with bowel obstruction
Hypovolaemia > AKI (due to third spacing)
Perforation
Ischaemia
What is third spacing
Mechanical blockage of bowel > proximal dilation with increased peristalsis > draws more water into bowel > HYPOVOL SHOCK
What are classical sx of bowel obstruction
severe abdominal pain, colicky, widespread
Vomiting (bilious)
Distension
Absolute constipation
What are cllassical ssx of bowel obstruction
guarding
rebound tenderness
tinkling bowel sounds
What is the initial investigation that they often get with bowel obstruction
Erect CXR (to check for free fluid under diaphragm)
OR abdominal XR (to look at bowel distension)
Whart is definitive Ix for bowel obstruction
abdo CT
What will the abdo x ray show for small bowel vs large bowel obstruction
small bowel: >3cm, central, valvulae conniventes
large bowel: >6cm (colon), >9cm (sigmooid), haustrae
What is approach for bowel obstruction
NBM immediately
Drip and Suck - NG tube with free drainage + IV fluid resus
Surgery (emergency laparotomy to resolve cause)
What is volvulus
Twisting of intestinal loop around its mesenteric attachment > closed loop bowel obstruction
What are complications of volvulus
Bowel has compromised blood supply > rapid ischaemia, necrosis and perforation risk
what are two different types of volvulus
sigmoid (80%) vs caecal (20%)
Explain characteristic patient of sigmoid volvulus
and what occurs
Older, chronic constipation
sigmoid bowel twists around mesentery > large bowel obstruction
What is the cause of a caecal volvulus
abnormality in development (falure of peritoneal fixation) that makes the volvulus at risk of twisting»_space; small bowel obstruction due to proximal large bowel obstruvtive cause
imaging of volvulus
sigmoid: AXR > COFFEE BEAN SIGN (+ normal LBO signs)
caecum: on AXR has normal SBO signs
CT ABDO PELVIS WITH CONTRAST > WHIRL SIGN
Management of sigmoid volvuluis
decompress with sigmoidoscope + flatus tube insertion
leave flatus tube in for up to 24h
if decompression fails repeatedly or peritonism: laparotony
Describe large bowel anatomy
Appendix > caecum > ascending colon > right colonic flexure > transverse colon > left colonic flexure > descending colon > sigmoid > rectum > anus
what is does a right hemicolectomy remove and when is it used?what type of anastamosis
the caecum and ascending coon
used for tumours in this caecum and proximal ascending colon
iliocolic anastamosis
what does an extended right hemicolectomy remove and when is it used?what type of anastamosis
caecum ascending colon and transverse colon
for tumours in distal descending colon or transverse oolon
iliocolic anastamosis
what is a left hemicolectomy used for, what does it remove? what is anastamosis
descending colon
for tumours in descending colon
colocolic anastamosis
what is hartmann’s procedure remove
sigmoid colon
when is hartmann’s used for
obstrution or perforation secondary to sigmoid tumour or diverticulitis – EMERGENCY
what colorectal procedures leave you with a stoma
Hartmsnn’s
AP resection
Anterior resection
where and what stoma do you get with Hartmann’s
single lumen colostomy in LIF
what is an AP resection
Abdominal Perineal Resection
aka BARBIE BUTT PROCEDURE
What does an AP resection remove
Abdominal incision: sigmoid, rectum and mesorectal nodes
Perineal incision: anus removed
what stoma do you get with AP resection
single lumen colostomy in LIF
what are indications forAP resection
rectal cancer LESS THAN 4-5 cm from anal verge ==> LOW RECTAL TUMOUR
(Anal Proximity tumour!!)
what are indications for anterior resection
rectal cancer MORE THAN 4-5 cm from anal verge ==> MID/HIGH RECTAL TUMOUR
you resect part of rectum and sigmoid colon
what stoma are you left with in anterior resection
DOUBLE LUMEN loop ileostomy in RIF
what are classical symptoms of colorectal cancer
change in bowel habit
PR bleed
WL, fatigue
ANaemia
what is the most important ix to get in suspected colorectal cancer
COLONOSCOPY
what colorectal cancer screening currently exists in UK
60-74 years old receive FIT test faecal immunochemical test (FIT) every 2 yearts
this is essentially a FOB that recognises antibodies against human Hb
what happens if FIT +ve
colonoscopy offered
How do you manage colorectal cancer
resection +-neoadjuvant chemo/radiotherapy
what is the most common type of abdominal hernia
INGUINAL hernia
what is the risk in a man of having an INGUINAL hernia
1 in 4
What are the two types of inguinal hernia?
INDIRECT vs DIRECT hernia
Explain INDIRECT hernia
Common in young boys
peritoneal sac protrudes through deep ingluinal ring > inglluinal canal > superficial ring > testes
due to weakness of deep inguinal ring (which is where structures pass during development to reach external genitalia=
Explain DIRECT inguinal hernia
DIRECT inguinal hernia
still more common in men, but this time RF are age, lifting heavy weights
peritoneal sac enters through weakening in abdominal wall eventually into inguinal canal (through superficial ring)
where are ingluinal hernias found
Above and medial to pubic tubercle
where are femoral hernias found
Below and lateral to pubic tubercle
Explain how femoral hernias occur
weakness in abdominall wall causes protrusion of intestinal content through femoral canal
WHo are femoral hernias most common in
WOMEN
due to large pelvis (which means tissues are more stretched)
What are femoral hernias at high risk of
strangulation and obstruction