Colorectal Flashcards
What are the histological features seen in Crohns
Granulomas (non-caseating)
What is the management of a patient with UC presenting with acute colitis
Medical mx= steroids for 5-7 days
What is the management of a patient with UC and colitis who is not responding to steroids
Emergency: subtotal colectomy with end ileostomy and mucocutaneous fistula
Management of crohns with ano rectal sepsis?
Very min resection if needed!!
Drain infection +/- seton to facilitate drainage
T/F: all colonic adenomas are metaplastic
FALSE: colonic adenomas are DYSPLASTIC
Why should colonic polyps not be resected in the presence of CRC during endoscopy
To avoid seeding
T/F: all colonic adenomas >1cm have malignant potential
FALSE:
Colonic adenomas >2cm have malignant potential
Patient presents with:
Painful PR bleeding on defecation
Skin tag present
Bright red blood
Diagnosis?
Fissure in ano
Conditions associated with fissure in ano
Crohns
TB
internal rectal prolapse
Management of obstruction due to diverticular stricture
Colonic resection
If malignant- stent
Management of volvulus
Initial max: untwist- flexi sig
If ischaemic: surgical
If recurrent: resection
Causes of LBO
Tumours
diverticular disease
volvulus
Mx of right sided colonic tumour causing LBO
RESUSCITATE
right hemi +/- extend to transverse
ileocolic anastamosis
Mx of left sided colonic tumour causing LBO
RESUSCITATE
left hemi + anastamosis
OR
Left hemi + end colostomy
OR
colonic stent
Mx of rectosigmoid tumour causing LBO
resection + loop colostomy
distal sigmoid= high anterior resection
What are the 4 types of fistulae
enterocutaneous
enterocolonic
enterovesical
enterovaginal
Management of a high output fistula
octerotide + TPN
Define Goodsall’s rule
For perianal fistulae:
if the outer opening of a fistula is anterior to the imaginary transverse line drawn across the perineum= the internal fistula opening (into the anal canal) is along the same radial path (fistula track is a straight line)
If the outer fistula opening is posterior to the imaginary transverse line= the fistula tract will follow a curved line and open at the posterior midline
Indication for surgical mx of UC
Dysplastic lesions found
UC requiring maximal therapy
Prolonged courses of steroids
In elective settings, what would be the surgical mx of UC
Panproctocolectomy + end colostomy/ ileoanal pouch
In emergency settings, what would be the surgical mx of UC
subtotal colectomy + end ileostomy +/- mucous fistula (if rectum is very odematous)
in emergency settings rectum should not be resected
Indications for surgical Mx of Crohns
Complications of crohns:
abscess, fistula, strictures
What is the surgical management of crohns:
If stricture
if perianal fistulae
if perianal/ rectal crohns
if terminal ileal crohns
Resection should be minimized to prevent shot bowel syndrome
If stricture= stricturoplasty
if perianal fistulae= seton drainage
if perianal/ rectal crohns= protectomy
if terminal ileal crohns= limited ileal resection
Commonest type of cancer in the:
anus
rectum
colon
Anus= SCC
rectum + colon= adenocarcinoma
What is commonly associated with chronic straining and constipation
solitary rectal ulcer
What is seen in histology of lesion associated with chronic straining and constipation
mucosal thickening
collagen and fibrosis in the lamina propria
What are the surgical management options for rectal prolapse and their associated complications
Delorme’s = high recurrence rate
Altemier’s= anastamotic leak
Rectopexy= constipation post-op
Where are fissure in ano usually sited
posteriorly
If fissure in ano present atypically what investigations should be carried out
Atypical= anteriorly sited/ multiple
colonoscopy, EUA + biopsies
*for ?Cancer/ IBD/ prolapse
What are the different management options for fissure in ano
1- stool softeners
2- GTN/ diltiazem top
3- botox injection
4- surgical:
men= laternal internal sphincterotomy
women= manometry (caution with sphincterotomy as when combined with post-vaginal birth pelvic floor damage, can cause faecal incontinence)
What is the commonest complication of ileostomy
dermatitis
What is the earliest complication of ileostomy
necrosis
Where are ileostomies usually sited
RIF (in the triangle between ASIS, pubic symphysis and umbilicus, 1/3 of the way b/w the umbilicus and ASIS)
How much output would be considered high output for an ileostomy
normal 5-10ml/kg/24hr
high >20ml/kg/24hrs
initial mx of high output ileostomy
-loperamide + add gelatin to food to thicken
management options for colonic pseudo-obstruction
Usually due to electrolyte imbalances
1- correct electrolytes + supportive care
2- decompress with rigid sigmoidoscope/ oral neostigmine
*neostigmine can cause symptomatic bradycardia= give in monitored environment
Complication of chronic pilonidal abscess
Management of acute pilonidal abscess/ sinus
I&D
Definitive mx of pilonidal abscess and when should this be done
Bascoms procedure- excising the pit and obliterating the cavity underneath
Karydakis procedure- wide excision of the natal cleft so that the surface is recontoured once the wound is closed
rectal cancer mx if:
-T1/2/3, N0
-T4
-rectal Ca presenting with obstruction
-surgical resection
-chemo-radiotherapy
-defunctioning loop colostomy
colon ca mx if:
-any stage
-high recurrence risk
-presenting with obstruction
-surgical resection
-resection + post-op chemo
-resection/ stent
Anal Ca mx:
-1st line
-2nd line
-chemoradiotherapy
-salvage radical AP excision of anus and rectum (for NON-metastatic ca)
What are the extra-intestinal manifestations of crohns
A PIE SAC
Apthous ulcers
pyoderma gangrenosum
erythema nodosum
sclerosing cholangitis
arthritis
clubbing
What is the transition from polyp to cancer called
adenoma-carcinoma sequence-where oncogenes are activated and tumour suppressor genes are DE-activated to gradually form cancerous cells
What are the genes involved in the transformation of a polyp to a carcinoma
APC
c-myc
bcl-2
K-RAS
MCC
DCC
c-yes
p53 deletions
What are the extra-intestinal manifestations common to both crohn and UC
Arthritis
PSC*
uveitis*
episcleritis**
pyoderma gangrenosum
erythema nodosum
clubbing
osteoporosis
*more common in UC
** more common in crohns
What is the most common extra-intestinal feature in both CD and UC
Arthritis
