Colorectal Flashcards
(85 cards)
1
Q
Altered bowel habit means?
A
Changes in
- Frequency
- Consistency
2
Q
How to estimate roughly how much blood is in stool?
A
How many times do they go toilet to pass out blood in a day
3
Q
Criteria for urgent referral colonoscopy within 2 weeks
A
> Unexplained rectal bleed with >= 1 of following:
- fresh blood
- blood mixed with stool
- altered bowel habit
- significant LOW
AND/OR
> Unexplained IDA
AND/ OR
> Palpable abdominal or rectal mass
4
Q
Symptoms of right CCA vs left CCA vs rectal ca
A
> Right
- IDA
- Abdominal mass (cauliflower type)
> Left
- Intestinal obstruction (annular ring tumour, lumen smaller)
> Rectal
- Tenesmus
- Mucoid stool
- Pencil-thin stool
5
Q
Investigation for colon Ca
A
> Diagnosis
- Colonoscopy (direct visualization, biopsy, detection of synchronous lesion)
> Staging
- CT TAP for CCA
- MRI rectum for rectal Ca
- EUS: depth of invasion
- PET and Bone scan
> Assess complicaiton
- FBC: IDA
- RP: increase Cr at risk of contrast nephropathy
- LFT: albumin for nutrition status, ALP for liver mets
- Erect and supine AXR: intestinal obstruction
- Erect CXR: air under diaphragm for perforated tumour
6
Q
Management of rectal Ca
A
> From anal verge
- 17-10cm: HAR
- 10-5cm: LAR
- 5-0cm: ULAR
- Sphincter involved: APR
> Total mesorectal excision
- as part of LAR for middle and lower rectum Ca
> According to staging
- T1: local excision
- T2: local excision + adjuvant chemo/ RT OR radical resection
- T3/4: Neoadjuvant CCRT before radical resection
7
Q
Follow up for colorectal Ca
A
- History, physical examination and CEA levels every 3-6 months for 5 years
- Surveillance colonoscopy at year 1 and every 3-5 years thereafter
- CT TAP performed annually for 3 years
8
Q
Bowel prep for colonoscopy
A
- Stop Fe tablet >5 days prior +- stop anticoagulant
- Low residual diet 2-5 days prior
- Clear liquid 1 day prior
- NBM 6-8 hours prior
- FLEET osmotic agent 2-3 packs (4pm, 8pm)
9
Q
TNM staging for colorectal Ca
A
> Primary tumor
- T1: invade submucosa
- T2: invade muscularis propria
- T3: invade through the muscularis propria into pericolorectal tissues
- T4a: penetrate to the surface of visceral peritoneum
- T4b: invades or adherent to other organs or structures
> Regional LN
- N1: 1-3
- N2: 4 or more
> Distance metastasis
- M0: No
- M1: Distance metastasis
10
Q
Consent for a colon operation
A
> Explain about the surgery
Risk and complication
- injury to BV which may cause bleeding
- bleeding which may require a blood transfusion
- risk of transfusion: transfusion reaction, cross-infection (eg: HIV, Hep B/C)
- risk of injury to surrounding organs (eg: small bowel, bladder, liver)
- post-operative - wound infection/ breakdown
- general anesthesia risk and complication
11
Q
Difference between ileostomy and colostomy
A
> Ileostomy
- RIF
- 3cm “spout” to prevent ileal content (corrosive) to contact the skin
- watery greenish output
> Colostomy
- LIF
- flushed to the skin
- firm brown fecal output
12
Q
Complication of stoma
A
> Early
- Infection
- Necrosis
- Obstruction (fecal impaction/ adhesion)
- Leakage
- Stoma diarrhea
> Intermediate
- Prolapse of bowel
- Retraction
> Late
- Parastomal hernia
- Stenosis
- Skin excoriation
- Fistulae
13
Q
Cause of increased output in stoma patient (>1000ml/day)
A
- Primary: loss of normal daily secretion (1.5L saliva, 2-3 gastric juice, 1.5L pancreatico-biliary)
- Other: intra-abdominal sepsis, infective enteritis, intermittent bowel obstruction
14
Q
What is rule of 2?
A
> For Merkel's diverticulum ○ 2 inches in length, 2cm wide ○ 2 feet (60cm) from ileocecal valve ○ 2% of the population ○ 2:1 ratio (M:F) ○ 2-4% symptomatic
15
Q
Investigation for Merkel’s diverticulum
A
○ Blood
§ Same as IO/ LGIB
○ Imaging
§ Meckel's scan
□ Technetium-99m pertechnetate scan
□ Detect gastric mucosa
§ Barium studies
□ Small bowel enterocolitis
16
Q
Definitive management of Merkel’s diverticulum
A
§ Broad base - wedge ileal resection with anastomosis
§ Narrow base - resection of the diverticulum
17
Q
What is pectate line
A
- Irregular circle form by anal valve
- Divide anal canal into endodermal and ectodermal origin
18
Q
What is McBurney point
A
- Point that lies 1/3 of the distance laterally on a line drawn from the umbilicus to the right ASIS
19
Q
3 cardinal features of appendicitis
A
- Low grade pyrexia
- Localized abdominal tenderness
- Muscle guarding and rebound tenderness
20
Q
Rovsing sign
A
RIF pain with deep palpation of the LIF
21
Q
Psoas sign
A
RIF pain with right hip flexed (as inflamed appendix lying on psoas muscles)
22
Q
Obturator sign
A
RIF pain with internal rotation of a flexed right hip (for pelvic appendix)
23
Q
Component of Alvarado score
A
> MANTRELS
- Migratory RIF pain
- Anorexia
- Nausea/ Vomiting
- Tenderness at RIF (2 points)
- Rebound tenderness
- Elevated temperature (>37.3’C)
- Leukocytosis (2 points)
- Shift of neutrophils to left
24
Q
Management of appendicitis
A
> Supportive
- NBM, IV drip, IV antibiotics
- Antiemetics and analgesia
> Definitive
- Appendectomy (open/ laparoscopic)
- Peritoneal toilet
25
Hinchey classification
> Staging for diverticulitis
* Stage 1 Pericolonic/ Mesenteric abscess
- Antibiotics, NBM, IV fluids
- KIV percutaneous drainage of acute pericolonic abscess
* Stage 2 Pelvic/ retroperitoneal abscess
- Percutaneous drainage under radiological guidance
- KIV elective 1 stage surgery - resection of segmental colectomy with primary anastomosis
* Stage 3 Purulent peritonitis * Debate whether same as stage 2 or 4
* Stage 4 Fecal peritonitis - 2 stage operation - Hartmann's procedure + secondary re-anastomosis 3 months later
26
Investigation for acute diverticulitis
- FBC: leukocytosis, ESR
- Erect CXR: r/o perforation
- AXR: ileus, air fluid level
- Contrast CT: diverticular elsewhere, confirm colitis
- Laparoscopic: if diagnosis doubt
- AVOID barium enema, colonoscopy
27
Management of acute diverticulitis
> Uncomplicated - CONSERVATIVE
- NBM
- Analgesia
- IV Abx (10-14 days)
- Colonoscopy 4-6 weeks later (confirm diagnosis + exclude colon Ca)
> Complicated - SURGICAL
28
Complication of acute diverticulitis
- LGIT hemorrhage
- Fistula formation
- Perforation (phlegmon -> diverticular abscess -> peritonitis)
- Bowel obstruction
29
Small vs Large bowel obstruction
> Small bowel
- More acute
- Central and colicky pain
- Early, profuse, biliary vomiting
- Radiological: central, 30mm diameter, valvular conniventes
> Large bowel
- More gradual onset
- Localized tenderness
- Vomiting: late, feculent, may be absent
- Radiological: peripheral, 60mm, haustra might present
30
Diagnostic investigation for intestinal obstruction
Erect AXR
- Air fluid level ≥5
Supine AXR
- Jejunum (>3cm), Colon (>6cm), Cecum (>9cm)
- Valvular conniventes/ Haustration might present
CT abdomen
- Perform if not complete obstructed
- Determine site/ cause of obstruction (transition point hard to see in X-ray)
Barium enema/ Gastrografin
- Rarely needed due to availability/ accuracy of CT
31
Hartmann's procedure describe
- Involves resecting the diseased colonic segment
- Creating an end colostomy and a rectal stump
- Reversing the colostomy in the future (50% did not perform due to technically difficult with high morbidity and mortality rate)
32
Risk factor colon Ca
> Modifiable
- Diet: red meat
- Lifestyle: smoking, alcohol
> Non-modifiable
- Age >40 years old
- Chinese
- Family history
- FAP/ HPNCC
33
HPNCC (Lynch syndrome) vs FAP
> HPNCC
- 1-3% of all CRC
- Autosomal dominant
- Age: >40 (15% cancer by 40)
- Fewer polyps
- Right-sided Ca
> FAP
- 1% of all CRC
- Autosomal dominant
- Age: 20 (90% cancer by 45)
- Usually >100 polyps
- Left-sided Ca (80%)
34
Surgery for sigmoid cancer + describe
- Sigmoid colectomy
- Removes the sigmoid colon, including the associated mesentery, with the inferior mesenteric vessels ligated close to their origin to optimally resect lymphovascular tissue
35
Complication for hemicolectomy
> Immediate
- Damage to ureter
> Early
- Anastomosis leakage
- Wound infection
- Bleeding
> Late
- Impotence
- Adhesion
- Tumor recurrence
36
Lanz vs Gridiron incision
Lanz incision
- Transverse
- More aesthetically pleasing
- Reduce scarring
Gridiron incision
- Oblique
37
Etiology of acute appendicitis
- Fecaliths
- Lymphoid hyperplasia
- Less common cause: Parasites, TB, Tumor, FB
38
Non-operative management of acute appendicitis
- Only when appendicular mass present
- Ochsner-Sherren regimen (hospitalization + IV fluid + antibiotics + analgesics + strict vital sign monitoring)
- 80-90% mass resolve without complication
- Debate continues as immediate surgery may reduce hospital stays and obviate need for second admission
39
Cause of umbilical pain in acute appendicitis
- Stimulation of visceral afferent nerve that arise from T10 (innervate umbilicus also)
- Well-localized pain later when involve adjacent peritoneum
40
Complication of appendicectomy
- Stump
- Hemorrhage
- Infection
- Paralytic ileus
41
How to classify intestinal obstruciton
- Pathological: mechanical vs functional
- Anatomical: small vs large
- Clinical: acute vs chronic
- Pathological changes: simple vs strangulated
- Severity: partial vs complete
42
Causes of intestinal obstruction
> More common
- Intraperitoneal adhesion
- Tumors
- Complicated hernia
> Others
- Volvulus
- Gallstones
- Intussusception
43
Definition keyword of surgical site infection
- 30 days following surgery
| - 90 days if implant involved
44
Type of SSI
- Superficial incisional SSI
- Deep incisional SSI
- Organ or space SSI
45
Imaging for acute appendicitis
> Abdominal ultrasound
- Diameter >6mm
- Peri-appendicular fluid collection
> CECT abdomen
- Enlarge diameter
- Thicken wall
- Fat stranding
- Appendicolith
> Erect CXR
- R/o perforation, lobar pneumonia
46
Investigation for PUD
> OGDS
- Confirmation + location
- Biopsy TRO malignancy, H. pylori
- Therapeutic
> FBC
- IDA if bleeding
- Leukocytosis if perforated
> Urea breath test
- H. pylori infection
47
Indication for biopsy PUD
- Malignant looking (irregular, thickened margin)
| - Benign looking but in area with high incidence
48
Management of peptic ulcer disease
> Medical and lifestyle
- PPI
- Smoking and alcohol cessation
- NSAID discontinue
- H. pylori eradication
> Endoscopic therapy
- Injection therapy
- Thermal coagulation
- Hemoclip
> Surgery
- Duodenal ulcer: Truncal vagotomy with pyloroplasty
- Gastric ulcer: Wedge resection/ Antrectomy/ Total gastrectomy
49
Describe H. pylori eradication therapy
> First line:
- Omeprazole 20mg BD for 6 weeks
- Amoxicillin 1g BD, Clarithromycin 500mg BD for 10-14 days
> If failed -> quadruple therapy
- Colloidal bismuth sub-citrate 120mg QDS, Tetracycline 500mg QDS, Metronidazole 400mg BD, Omeprazole 20mg BD for 7-14 days
50
How and where injection adrenaline peptic ulcer
- 30ml diluted adrenaline (1:10000)
| - 4 quadrant around the ulcer
51
Describe CLO test
- Urease convert urea into ammonia that raise pH of medium, detect by phenol red and color changed from yellow (negative) to red (positive)
52
Risk factor for SSI
> Non-modifiable
- Older age
> Modifiable
- Cigarette smoking
- Vascular disease
- Obesity
- Malnutrition
- Diabetes
- Immunosuppressive disease
53
How TB infection cause intestinal obstruction
- Through progressive stricture and adhesion
54
Cause of persistent high CEA after colon ca resection
- Overlooked metastases
- Inadequate surgery
- Smoking habit
- Renal insufficiency
- Chronic liver disease
55
What is CEA
- Protein normally found in embryonic or fetal tissue
- Serum level disappear almost completely after birth, but small amount may be present in colon
- Elevated in malignancy that produce the protein (eg: GIT, ovary)
56
Ulcerative colitis vs Crohn's disease
> Ulcerative colitis
- Affects only large intestine
- Continuous inflammation
- Mucosal and submucosal affected
> Crohn's disease
- May affect any part of the GIT
- Discontinuous patchy inflammation
- Transmural (affects the full thickness of the bowel wall)
57
Why Crohn's disease cause fistula
- Due to the transmural inflammatory nature of Crohn's disease that lead to formation of sinus tracts or fistula
- Eg: enterovesical, enterocutaneous, enteroenteric, enterovaginal
58
When do we do reversal of Hartmann
- At least after 6-9 months (No consensus yet)
- Allow the adhesion to soften, reducing operative difficulty
- Longer time may have inferior outcome -> due to shrinkage of rectal stump?
59
Complication of reversal of Hartmann
- Anastomotic leakage
- Wound infection
- Incisional hernia
- Ileus
* Complication rate high, reason why many patient never reverse
60
Principle of colon Ca surgery
- En-bloc resection of tumor: 5cm proximally and distally
- Resect adjacent draining LN
- Reconstruct the bowel, if possible
61
Chemotherapy regime for colon Ca
- Initiate within 6-8 weeks of surgery
- 6 months course of oxaliplatin based regimen
(FOLFOX: oxaliplatin + leucovorin and short term infusion 5-FU)
- Each cycle last 2 weeks (2 days infusion, 12 days rest), might up to 12 cycles
62
How to follow up after colon Ca
- 3 monthly for the first 2 years, then 6 monthly for the next 3 years, and subsequent yearly
- History, PE, and CEA every 3-6 months for 5 years
- Surveillance colonoscopy at year 1 and every 3-5 years thereafter
- CT TAP performed annually for 3 years
63
Complication of colonoscopy
- Complication related to sedation (eg: cardiopulmonary)
- Complication related to preparation (eg: fluid and electrolyte imbalance, abdominal bloating)
- Perforation (from mechanical trauma, barotrauma, or electrocautery injury during polypectomy)
- Infection (rare, due to improper endoscope reprocessing)
64
Management of perforation during colonoscopy
- Immediate erect CXR - air under diaphragm
- NBM, IV fluid, IV Abx
- Surgical consultation immediately
65
Dukes' classification
- A: confined to mucosa
- B1: growth into muscularis propria
- B2: growth through muscularis propria and serosa
- C1: spread to 1-4 regional LN
- C2: spread to >4 LN
- D: distance metastasis
66
TMN vs Duke's classification
- TMN is preferred over traditional Duke classification
- Duke primarily to determine prognosis
- TMN can aid determination of optimal therapy and assessment of response to therapy
67
Clinical sign of anastomotic leak
- Pain
- Fever
- Peritonitis
- Feculent drainage
- Purulent drainage
68
Management of anastomotic leak
- IV fluid resuscitation and broad spectrum Abx
- Bowel rest, percutaneous drainage
- Colonic stenting
- Surgery: resection of the anastomosis with end stoma/ resection of the anastomosis with re-anastomosis and proximal diversion
69
Open vs Laparoscopic appendectomy for perforated appendicitis
> Open
- Lower intra-op complication
- Lower hospital cost
> Laparoscopic
- Shorter hospital stay
- Lower risk of SSI
- Feasible for experience surgeon
70
Therapeutic function of colonoscopy
- Polypectomy
- Endoscopic hemostasis
- Dilation of colonic or anastomotic strictures
- Stent placement for malignant disease
- Endoscopic mucosal resection/ submucosal dissection of GIT tumor
- Foreign body removal
71
Screening for colorectal ca
> Average risk
- No family hx, age >50
- Yearly iFOBT, stop at 75
> Moderate risk
- >1FDR; 1FDR and >1 SDR; >3 and one must be FDR
- Diagnosed <60 y/o: colonoscopy @ age 40/ 10 year younger than affected FDR; repeat 3-5 years
- Diagnosed >60 y/o: colonoscopy @ age 40; repeat 10 years
- Stop at 75
> High risk
- CRC <50, FAP, HPNCC
- Colonoscopy @ age 40/ 10 year younger than affected FDR; repeat 3-5 years
72
When can patient return to activity after appendicectomy
- Jogging: 1 week
| - Weight lifting: 3 months
73
If do open surgery and found appendix not inflamed
- Still remove the appendix to avoid future confusion due to the scar
74
Cause of terminal ileitis
- Crohn's disease
- NSAID use
- Tuberculosis
- Radiation
- Autoimmune disorder
75
What are Batson plexus
- Network of paravertebral veins with no valve drain the bladder, prostate, and rectum to the internal vertebral venous plexus
- Provide route for cancer metastases or infection to the spine
76
Define synchronous tumor
- Second primary cancer is diagnosed within 6 months of the primary cancer; (metachronous = more than 6 months)
77
Signs of bowel viability
- Color of serosa surface
- Presence of bowel peristalsis
- Pulsation and bleeding from the marginal artery
78
Investigation for intestinal obstruction
> Diagnosis
- Erect/ Supine AXR
- CT abdomen
- Barium enema
> Complication
- BUSE/ Cr (electrolyte imbalance)
- ABG (alkalosis from vomiting)
79
Management for intestinal obstruction
> Acute management
- Keep NBM, NG tube suction
- Analgesics
- Urinary catherization to monitor urine output
- Correct electrolyte abnormalities
- Surgical intervention: strangulated/ failed conservative >72 hours
80
Presentation of gastric outlet obstruction
- Epigastric pain
- Nausea, vomiting
- Early satiety
- Abdominal distension or bloating
- Weight loss
81
Condition associated with multiple anal fistula
- Crohn disease
- TB
- Actinomycosis
82
Describe Goodsall's rules
- Used to predict the trajectory of fistula tract
- All fistula tracks with external opening within 3cm of the anal verge and posterior to a line drawn through the ischial spines travel in a curvilinear fashion to the posterior midline
All tracks with external openings anterior to this line enter the anal canal in a radial fashion
- Fistula tracks longer than 3cm from the anal verge do not necessarily follow Goodsall’s rule; they often have an internal opening in the posterior midline
83
X-ray finding for sigmoid volvolus
- Coffee bean sign
- Distended large bowel proximal to the sigmoid
- Air fluid level in the small bowel
84
2 causes of sigmoid volvulus
- Anatomic factors: long redundant sigmoid colon with narrow mesenteric attachment
- Colonic dysmotility: prolonged colonic transit through the sigmoid colon and rectum
85
Management for sigmoid volvulus
- Sign of perforation/ peritonitis -> immediate surgical resection management; generally, should not have their volvulus detorsed to avoid reperfusion injury
- No sign of perforation/ peritonitis -> flexible sigmoidoscopy to detorsed the twisted segment, if successful, surgical resection shortly thereafter
