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
What type of hernia respods to cough impulse
INGUINAL
what is incarceration of a hernia
hernia CANNOT be reduced
what is strangulation of a hernia
hernia becomes ischaemic due to compromised blood supply
What do you do if hernia is incarc / strangulated?
EMERGENCY surgery
what do you do if hernia is not strangulated / incarc?
depends on type of hernia
if inguinal: ruotine repair, even if asymptomatic
if femoral: urgent repair (due to high risl of strangulation)
What are the two approaches to femoral hernia repair
if eLective: Lockwood Low approach (low incision over hernia with herniotomy/herniorrhaphy)
if eMergency: McEvedy High approach (via inguinal region to inspect and resect non viable bowel)
What are the types of surgery you can use for hernia repar
herniotomy: ligation + excision of hernial sac
herniorrhaophy: repair of abdo wall defect
hernioplasty: mesh implant
what incisions do you leave for herni repain
McBurney (oblique)
Lanz (transverse)
how do you differentiate between direct and indirect inguinal hernia
- reduce the hernia
- press on deep inguinal ring
- Ask patent to cough
if the hernia is DIRECT: it will protrude
if hernia is INDIRECT: it will NOT protrude as you are blocking its way out
what does pain suggest in jaundice?
PAINFUL jaundice = gallstone disease
painLESS jaundice = pancreatric cancer
what is toxic megacolon
acute colonic distension (dilatation >6cm on AXR) + systemic symptoms of infection (fevers, shock)
causes of toxic megacolon
- IBD (most common - most likely UC)
- C diff
- Ischaemic colitis
- bowel cancer
- volvulus
risk with toxic megacolon
likely to PERFORATE»_space; death
Ix toxic megacolon
SEPSIS 6
Ix: FBC, CRP, UE, LFT, stool sample
AXR and abdo CT
Mx of toxic megacolon
NBM Drip and suck start IV Abx Involve surgeons early If no improvement within 72 hours / deterioraton: take for emergency laparotomy
how does perforation show on CXR
free air under diaphragm BILATERALLY
how does perforation show on AXR
RIGLER SIGN = double wall sigh
Both the LUMINAL surface and the SEROSAL surface are seen.
** the SEROSAL surface should not be visible as it is normally in contact with other intra-abdominal content of similar density (other loops of bowel, omentum, fluid).
what is MESENTERIC ADENITIS
inflammation of the mesenteric lymph nodes - due to infecton (adenovirus, EBV, beta haem step)
how does MESENTERIC ADENITIS present
Similar to appendicitis - except for HIGH FEVER
what does laparotomy show on mesenteric adenitis
enlarged mesenteric lymph nodes
What is meckels’ diverticulitis - and how does it present
ectopic gastric mucosa
RIF pain (worse after eating) bleeding (IDA)
what investigation is important if anal fistula in Chrons
get an MRI to check track of fistula
what does an ileostomy drain?
the SMALL BOWEL (ILEO = ileum)
Where is an ileostomy typically?
RIF
What does an ileostomy shape typically loook like?
SPOUTED
due to the acidic nature with high enzyme contents, which irritates the surrounding skin. A spout minimises this
what is output of ileostomy like?
LIQUID to SEMI-LIQUID output (as this is small bowel content)
Usually high output, so 500ml - 1L/day
where is a colostomy usually located
LIF
what is the shape of a colostomy look like
FLUSH to the skin
what does the content of a colostomy looko like
Semi solid to solid (faecal matter) low output (200-300ml)
when do you do a double lumen (loop) stoma
both ends connect out
this is temporary, to allow distal bowel to rest. Wll then be reversed
complications of stoma
immediate: bleeding, necrosis from poor blood supply
early: high outpput causing dehydration and micronutrient lot, obsructon, retraction
late: obstruction, prolapse (out of skin), parasternal hernia (contained within the skin), skin irritation, psych
what do you do if at GP, seen pt >60 with IDA?
URGENT referral to colorectal team for COLONOSCOPY +- OGD
what is the method of inheriitance of FAP
Autosoml DOMINANT
mutation of APC gene
what occurs in FAP
mutation of APC gene
hundreds of colonic adenomas develop
so the cancer risk is 100%
how do you manage FAP
annual flexi-sigmoidoscopy from age of 15
if no polyps found > 5 yearly colonoscopy from 20y
if polyps found > resection
method of inheritaance of Peutz-Jeguers
autosomal DOMINANT
presentation of Peutz-Jeguers
multiple benign intestinal hamatomas + PIGMENTATION PATTERN
can cause episodic obstruction or intussusception
risk of GI cancer and risk of breast, ovarian, cervical, pancfreatic and testicular cancers
how do you screen for peutz jeugers
intestinal endoscopy every 2-3 yeas
cancers associuated with HNPCC
COLORECTAL + Endometrial, gastric, pancreatic cancer
which geneit condition needs prophylactic surgery
HNPCC
what situations require a 2ww colorectal referral
- over 40 with WL and abdo pian
- over 50 with rectal bleed
- over 60 with IDA
- FOB+ve
what are the two commonest post op complications of colorectal tumour resection
ileus
anastamotic dehiscence
what occurs with ileus after colorectal tumour resection
peristalsis stops > electrolytes and fluid dissolve into lumen > low electrolytes in blood and dehydrated picture despite normla fluid balance
how do you manage ileuas
NG tube + fluids
how does an anastamotic dehiscence present
day 6, fever, septic picturw
which area of the gut has the WORSE perfusion
the splenic flexure (between transverse and descending colon=)
mangement of caecal volculus
lapatotomy (right hemicolectomy often needed)
what key sx does rectal intussusception (internal rectal prolapse) present with
obstructed defecation – associated with childbirth
what kinds of surgery are commonly done with chron’s disease
perianal fistula = seton suture
perianal disease = proctectomy
terminal ileum = iliocaecal resection
which procedure must you avoid in chroons and why
avoid ILIOANAL POUCH
high risk of failure
what is a total proctocolectomy
complete removal of large inteestine (colon) and rectum (procto)
what is a subtotal colectomy
removal of colon but NOT of rectum
what is the indication for ilio-anal pouch
used for UC after a SUBTOTAL COLECTOMY
can only be performed if the rectum is still in place (as patient still needs to pass stool. by themselves > still need to have rectal continence)
avoids a stoma! :)
what surgery is classically done in UC patient in emergency situation
subtotal colectomy + loop ileostomy
later consider ilioanal pouch to avoid stoma bag
ilioanal pouch complications
anastomotic dehiscence
pouchitis
poor physiological function with seepage and soiling.
what marker is used to monitor the response to treatment in colorectal cancer?
CEA
what is the important finding that you see in the rest of the bowel with a caecal volvulus
no other gas findings in the rest of the bowel
becuase NOTHING can get through
where are primary anal fissures (due to constipation) most likely located
90% are posterior
10% anterior
what do lateral anal fissures inidicate
that the anal fissure is the secondary conodition > look for the cause!
how do you manage a pt with mild diverticulitis
and what do you do if they do not improve
oral abx, send home
if do not improve within THREE DAYS
admit for CEF AND MET IV
sx of acute diverticulitiis (esp location of pain)
Severe LIF pain (as sigmoid colon is where colon narrows down)
bloody stool
fever
urinary sx (diverticular fistulation into bladder)
explain dukes staging for colorectal cancer
Dukes A: confined to mucosa
B: through bowel wall
C: lymph node invasion
D: distant mets
when do you need to do a laparotomy in sigmoids volvulus
if PERITONITIC (so skip sigmoidoscopy) or if REPEATED FAILED ATTEMPTS
what is the key sx difference between haemorrhoids and anal fissures in MCQ land
haemorrhoids are painless (unless thrombosed)
mx of anal fissure
<6weeks: dietary advice, bulk-forming laxatives
>6 weeks: try topical GTN or topical diltaziem, nifedipine
after 8 weels:_ refer for sphincterotomy of botulinum toxin
triad of gastric volvulus
vomiting
pain
failed attempts at passing NG tube
what kind of stoma should you aim for in distal bowel cancer
a loop ileostomy
to allow rest of distal bowel prior to reversal
when would you use IV iron compared to PO
when:
- oral replacement is ineffective or intolerable
- ferritin is very low and needs to be replaced very quickly
what investigation must you do to ensure that anastamosis has healed
GASTROGAFFIN contrast enema
