Lower GI Surgery Flashcards

(253 cards)

1
Q

what is Meckel’s Diverticulum formed from?

A

ileal remnant of vitellointestinal duct

(joins yoke sac to midgut lumen)

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2
Q

features of meckels’ diverticulum?

A

a true diverticulum

2 inches long

2 ft from ileocaecal valve

2% of population

2% symptomatic

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3
Q

what type of tissue does meckel’s diverticulum contain?

A

ectopic gastric

or pancreatic tissue

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4
Q

presentation of symptomatic meckels’

A

rectal bleeding - from gastric mucosa

diverticulitis mimicking appendicitis

intussusception

volvulus

malignant change: adenoca

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5
Q

hernia containing meckel’s diverticulum

called?

A

Littre’s Hernia

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6
Q

what is the investigation of choice for meckel’s diverticulum?

A

Tc 99 (Technetium-99m) pertechnetate scan

  • detects gastric mucosa
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7
Q

Mx of Meckel’s Diverticulum

A

Surgical resection if symptomatic

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8
Q

Tc-99 pertechnetate scan -?

A

Meckel’s Diverticulum

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9
Q

causes of intussusception

A

idiopathic

hypertrophied peyer’s patch- following bacterial/ viral GI infections

Meckel’s Diverticulum

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10
Q

presentation of intussusception?

A

episodic inconsolable crying

drawing up legs

-> colicky abdo pain

redcurrant jelly stools

sausage-shaped abdo mass

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11
Q

mx of intussusception

A

resuscitation, nil by mouth, x-match

Reduction by rectal air insufflation

(perform in theatre)

25% failure - conduct surgery

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12
Q

presentation of mesenteric adenitis

A

abdo pain

presents similarly to appendicitis

fever

tenderness

  • post URTI/ concurrent URTI
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13
Q

differentiating features

mesenteric adenitis vs appendicitis

A

progressively better rather than worse

post viral infection

headache +

higher temp

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14
Q

Types of malignant small bowel neoplasms?

A

AdenoCa (40%)

Carcinoid (40%)

Lymphoma (EATL assoc w Coeliac)

GI stromal tumours

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15
Q

presentation of small bowel malignancies

A

often presents late due to non-specific symptoms

weight loss, abdo pain

N+V, obstruction

bleeding

jaundice from biliary obstruction/ liver mets

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16
Q

Imaging of Small Bowel Cancer

A
  • abdo Xray: SBO
  • Barium follow through (Small bowel)
  • CT scan
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17
Q

features of duodenal atresia?

A

polyhydramnios

vomiting - usually bile stained

distended stomach

strongly associated w downs syndrome

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18
Q

diagnosis of duodenal atresia?

A

abdo x ray : double bubble sign

ie. distension of stomach and proximal duodenum w absence of gas throughout the rest of the bowel

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19
Q

tx of duodenal atresia

A

duodenojejunostomy

or

gastrojejunostomy

+ rehydration and gastric aspiration

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20
Q

syndrome in which a non-insulin-secreting islet cell tumour of the pancreas produces a potent gastrin-like hormone

A

zollinger-Ellison syndrome

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21
Q

Zollinger-Ellison syndrome:

what is produced that leads to the ulceration?

A

multiple ulcers due to potent gastrin-like hormone

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22
Q

why do NSAIDs predispose to peptic ulceration?

A

NSAIDs inhibit the production of protective prostaglandins in the mucosa

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23
Q

what medications may increase risk of peptic ulceration?

A

NSAIDs

steroids

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24
Q

what lifestyle factors may lead to increased risk of peptic ulceration?

A

smoking

stress

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25
peptic ulcer assoc with elevated intracranial pressure?
Cushing's ulcer
26
peptic ulcer assoc w severe burns?
Curling's Ulcer a complication from severe burns when reduced plasma volume leads to ischemia and cell necrosis (sloughing) of the gastric mucosa.
27
episodic epigastric pain usually 2 h after meal pain aggravated by spicy foods and relieved by milk and alkalis
Duodenal ulcer
28
ix with suspected duodenal ulcer?
endoscopy: to visualize oesophagus, stomach and duodenum and obtain biopsy to differentiate between benign/malignant ulcer H pylori detection: - endoscopic biopsy (urease test), 13C-labelled urea breath test, seological testing of Hy pylori antibodies Faecal occult blood often positive.
29
complications of peptic ulcer
chronicity - long term symptoms of pain perforation stenosis haemorrhage gastric ulcers may undergo malignant change
30
tx of peptic ulcer 1st line
eradication of H pylori. Omeprazole (PPI for acid reduction) + Clarithromycin/ Amoxicillin + metronidazole
31
what to avoid when a peptic ulcer is present?
violent gastric acid stimulants e.g. alcohol medications e.g. aspirin/ NSAIDs smoking stress
32
How were gastric ulcers surgically treated traditionally?
Billroth I gastrectomy.
33
what was a traditional surgical procedure for duodenal ulcers?
Simple longitudinal duodenotomy, closed as a pyloroplasty, with under-running of the bleeding vessel performed + acid suppression w PPI and Polya gastrectomy with under-running of the vessel
34
surgical tx of gastric / duodenal ulcers?
gastric ulcers: antrectomy + Roux-en-Y gastroenterostomy duodenal ulcers: removing the bulk of the acid-secreting area of the stomach (the body and the lesser curve), and re-establishing gastric drainage via a Roux-en-Y gastroenterostomy
35
causes of constipation? organic obstruction
- colon carcinoma - diverticular disease
36
causes of constipation? painful anal conditions
anal fissure prolapsed piles
37
causes of constipation? causing an adynamic bowel
Hirschsprung's senility spinal cord injuries and disease myxoedema Parkinsons' disease
38
causes of constipation? drugs
aspirin opiate analgesics (codeine e.g.) anticholinergics ganglion blockers
39
causes of constipation? habit and diet
dehydration starvation dyschezia (suppression of urge to defecate) lack of bulk in diet
40
what is a true vs a false diverticulum?
true: an outpouching covered by all the layers of the bowel wall e. g. Meckel's diverticulum false: lacking the normal muscle coat of the bowel e. g. colonic diverticula
41
what are the appendices epiploicae?
epiploic appendices are small pouches of the peritoneum filled with fat and situated along the colon, but are absent in the rectum.
42
gas in the urine called?
pneumaturia
43
most common cause of colovesical fistula?
diverticulitis
44
ix of diverticulitis?
CT abdo Sigmoidoscopy (fibreoptic sigmoidoscopes)/ Colonoscopy Barium Enema
45
what can a rigid sigmoidoscope visualize?
rectum only
46
tx of acute diverticulitis
conservative mx - fluid diet - antibiotics (metronidazole w penicillin/ gentamicin)
47
ix of angiodysplasia?
colonoscopy - lesions appear as bright red 0.5cm-1cm diameter submucosal lesions w small, dilated vessels mesenteric angiogram - contrast medium leaks into the lumen
48
tx of angiodysplasia
blood transfusion if haemorrhage severe colonoscopic electrocoagulation or argon plasma coagulation may be curative resection may be necessary
49
five main causes of colitis
1. UC 2. Crohns colitis 3. antibiotic-associated colitis 4. Infective colitis 5. Ischaemic colitis
50
ulcerative colitis - is smoking protective or not?
yes
51
ulcerative colitis pathology?
crypt abscesses oedema and submucosal fibrosis in walls of colon smooth, atrophic mucosa bowel wall thinned
52
local complications of ulcerative colitis
toxic dilatation -\> peritonitis haemorrhage stricture malignant change perianal disease
53
diarrhoea of ulcerative colitis may be controlled by?
codeine phosphate loperamide
54
what medication to induce remission in an acute attack of ulcerative colitis?
corticosteroids
55
what medications to maintain remission of UC?
salicylates such as mesalazine or sulfasalazine or anti-TNF antibodies infliximab or adalimumab or azathioprine/ ciclosporin
56
indications for surgery in UC?
fulminating disease not responding to medical treatment chronic disease not responding to medical tx prophylaxis against malignant change w long-standing disease complications of colitis \*usually total removal of the colon and rectum w either a permament ileostomy or an ileoanal anastomosis
57
non-invasive screening test for familial adenomatous polyposis?
affected individuals usually have hypertrophy of the retinal pigment layer
58
symptoms of colon ca?
change in bowel habit intestinal obstruction perforation of the tumour
59
what adjuvant chemotx is used post-operatively w colon cancer?
5-fluorouracil (5-FU) with folinic acid
60
what does the superior mesenteric artery supply?
midgut components e.g. caecum, ascending colon, 2/3 of the transverse colon
61
what does the inferior mesenteric artery supply?
hindgut components e.g. distal transverse colon, descending colon, sigmoid and rectum
62
what is the watershed area of the colon?
the area between the superior and inferior mesenteric artery supply
63
what surgical mx of a right sided lesion?
right hemicolectomy w ileocolic anastomosis
64
what surgical mx of a left sided lesion?
left hemicolectomy or sigmoid colectomy w anastomosis of colon to rectum
65
What surgical mx of a sigmoid lesion?
sigmoid colectomy elective or emergency (Hartmann's)
66
indications for colostomy formation
to divert faeces to allow healing of a more distal anastomosis or fistula to decompress a dilated colon, as a prelude to resection of the obstructing lesion removal of the distal colon and rectum
67
what is a loop colostomy?
colon brought to surface and antimesenteric border opened rod used to stop opened bowel loop from falling back inside - used to divert faeces and is simple to reverse - loop ileostomy preferred because of better blood supply to the bowel facilitating subsequent closure
68
complications of colostomy formation
retraction: colon disappears down the hole stenosis: opening becomes smaller. may be due to ischaemia or poor apposition of colonic mucosa w skin edge paracolostomy hernia: peritoneal contents herniate through the abdo wall defect made to accommodate the stoma prolapse: in which colon intussuscepts out of the stoma lateral space small bowel obstruction skin excoriation due to ill-fitting stoma appliances or poorly constructed stomas
69
why are ileostomies spouted?
ileostomy effluent is very irritant and causes severe skin excoriation -\> ileostomy constructed w a spout to keep the effluent off the skin
70
what helps stoma patients produce bulky, formed stool?
Fybogel or Celevac
71
what are the usual positions of haemorrhoids in a patient?
3, 7 and 11 oclock
72
How to grade haemorrhoids?
Grade I: confined to anal canal II: prolpase on defecation and reduce spontaneously III: prolapse on defecation and manually replaced IV: remain prolpased outside anal margin at all times
73
predisposing factors to haemorrhoids
may be aggravated by factors that produce congestion of the superior rectal veins e.g. pregnant uterus cardiac failure pelvic tumour excessive use of purgatives chronic constipation rectal ca
74
what to do examination/ investigation wise when suspecting haemorrhoids
1. examination of abdomen to exclude palpable lesions of the colon or aggravating factors for haemorrhoids (pelvic mass e.g.) 2. Rectal exam 3. Proctoscopy 4. Sigmoidoscopy to eliminate lesion higher in the rectum 5. Colonoscopy or flexi sigmoidoscopy when symptoms point to a more sinister condition than internal haemorrhoids
75
complications of haemorrhoids
anaemia: following severe/ continued bleeding thrombosis: prolapsed piles strangulated by anal sphincter -\> painful + suppuration/ ulceration may occur
76
conservative advice for haemorrhoids
pt should avoid straining at stool and aim to pass a firm, soft motion daily. bulk laxative + adequate fluid intake
77
mx of haemorrhoids
1st line: band ligation then sclerotherapy (for first / second degree haemorrhoids) surgery- haemorrhoidectomy for 3rd/4th degree haemorrhoids
78
what does banding of haemorrhoids involve?
application of small O-ring rubber band to areas of protruding mucosa - \> strangulation of mucosa - \> falls away after few days must be placed above the detate line, if not pt would feel the application
79
mx of thrombosed strangulated piles?
foot of bed elevated opiate analgesia local cold compresses often thrombosed piles fibrose completely w spontaneous cure or haemorrhoidectomy at once
80
complications of haemorrhoidectomy
acute retention of urine due to discomfort post-operatively stricture - when excessive amounts of skin are excised post operative haemorrhage
81
anal fissures- usual position?
posterior in the midline
82
tx of anal fissures
local anaesthetic ointment + lubricant laxative + GTN or diltiazem cream to relax the anal sphincter
83
what is a fistula?
an abnormal communication between two epithelial surfaces
84
what is a sinus?
a granulating track leading from a source of infection to a surface
85
tx of superficial and low-level anal fistulae?
laid open and allowed to heal by granulation
86
mx of high fistulae (suprasphincteric, transsphincteric)
fistula track can be injected w fibrin glue/ bio-prosthetic fistula plug or lower part of the track laid open and a seton passed through the upper part of the track and left for 2-3 wks so that the spincter is fixed by scar tissue. the track is then divided by repeated tightening of the ligature.
87
Systematic approach of AXR?
1. Bowel Gas Pattern - bowel diameter - position 2. extraluminal gas (under diaphragm, riglers sign) 3. Soft tissues 4. Calcification 5. Masses 6. Bones
88
Difference between small and large bowel on AXR?
Small bowel: more central normal diameter \<3 cm valvulae conniventes - which go across the whole colon Large bowel: more peripheral - can see ascending, transverse and descending colon haustra (only go part of the way across) normal diameter of transverse \<6 cm caecam \< 8cm
89
Presence of valvulae conniventes cluster of dilated small bowel loops in the central abdomen -\> Small bowel obstruction (ileus would usually affect both large and small) most common cause: adhesions from prev surgeries
90
dilated large bowel from caecum to mid descending colon diagnosis: large bowel obstruction (small bowel not obstructed here bec ileocaecal valve is still competent)
91
gas on both sides of bowel wall Rigler's sign diagnosis: intestinal perforation w free intraperitoneal gas
92
gas under diaphragm -\> perforation
93
Distended loop of colon (see haustra) arising from pelvis diagnosis: sigmoid volvulus (twisting of segment of bowel around its mesentery)
94
large calcific opacity overlying right renal outline upper part is same shape as renal collecting system diagnosis: right renal staghorn calculus
95
multiple opacities within the pancreas -\> chronic pancreatitis
96
Gallstones e.g. calcium oxalate
97
Pregnancy - see fetal spine, skull, legs in general, women of child bearing age imaging of abdo / pelvis using ionising radiation should be restricted to the 10 days following menstruation
98
presentation of small bowel neoplasm?
often non specific symptoms so present late n/v, obstruction weight loss and abdo pain bleeding jaundice from biliary obstruction or liver mets
99
imaging of small bowel neoplasia?
AXR: SBO Ba follow through CT
100
types of benign small bowel neoplasms?
adenomatous polyps (FAP, Peutz-Jeghers) Haemangioma Neurofibroma Leiomyoma Lipoma
101
What gut lymphoma is assoc w coeliac disease?
Enteropathy associated t cell lymphoma (EATL)
102
carcinoid tumours are?
neuroendocrine tumours of enterochromaffin cell origin capable of producing 5HT may secrete: 5-HT, VIP, gastrin, glucagon, insulin, ACTH most commonly in appendix
103
features of carcinoid syndrome?
flushing: paroxysmal, upper body +/- wheals intestinal: diarrhoea valve fibrosis: tricuspid regurg and pulm stenosis wheeze: bronchoconstriction tryptophan deficiency -\> pellagra (3Ds - dementia, diarrhoea, dermatitis)
104
ix of carcinoid syndrome?
increased urine 5-hydroxyindoleacetic acid CT/MRI: find primary
105
mx of carcinoid syndrome?
symptoms: octreotide or loperamide curative: resection
106
what is carcinoid crisis?
massive mediator release -\> vasodilation, hypotension, bronchoconstriction, hyperglycaemia
107
mx of carcinoid crisis?
high-dose octreotide
108
definition of appendicitis?
inflammation of the vermiform appendix randing from oedema to ischaemic necrosis and perforation
109
reason behind pattern of abdo pain in acute appendicitis?
early inflammation -\> appendiceal irritation nociceptive info travels in the sympathetic afferent fibres that supply the viscus -\> pain referred to dermatome corresponding to spinal cord entry level of these sympathetic fibres appendix = midgut = (T10/11) Late inflammation -\> parietal peritoneum irritation - pain localised in RIF
110
signs of Acute appendicitis?
guarding and tenderness @ McBurney's point (1/3 between asis and umbilicus) appendix mass may be palpable in RIF Rovsing's sign: pressure in LIF -\> more pain in RIF Psoas sign: pain on extending the hip- retrocaecal appendix Cope sign: flexion + internal rotation of R hip -\> pain - appendix lying close to obturator internus
111
mx of acute appendicitis?
prep for theatre: NBM, x-match, G+S fluids abx: cef n met analgesia: paracetamol, NSAIDs, codeine diagnostic lap uncertain dx -\> acute observation
112
complications of acute appendicitis?
appendix mass appendix abscess perforation: deteriorating pt w peritonitis
113
smoking in crohns vs UC?
smoking protective in UC but increases risk in Crohns
114
pathology of UC vs Crohns?
UC: continuous mucosal inflammation from rectum upwards shallow, broad ulcers Crohns: transmural inflammation from mouth -\> anus esp terminal ileum skip lesions strictures cobblestone mucosa marked fibrosis granulomas fistulae
115
skin findings in IBD?
clubbing erythema nodosum pyoderma gangrenosum (esp UC)
116
eyes symptoms in IBD?
anterior uveitis conjunctivitis episcleritis scleritis
117
joints in IBD?
(enteropathic) arthritis sacroilitis ank spond
118
hepatobiliary features in IBD?
PSC + cholangiocarcinoma (UC) gall stones (esp crohns) fatty liver
119
extra- abdominal features of IBD?
Crohns: aphthous ulcers, glossitis perianal abscesses, fistulae, tags anal strictures amyloidosis oxalate renal stones (esp crohns)
120
Ix in Ulcerative colitis?
Bloods: FBC etc blood cultures Stool cultures to exclude infectious cause Imaging: AXR- megacolon, wall thickening CXR - perforation Ba/ gastrograffin enema ileocolonoscopy + regional biopsy
121
Barium/ gastrograffin enema findings of Ulcerative colitis?
Lead pipe colon: no haustra thumbprinting: mucosal thickening pseudopolyps: regenerating mucosa
122
In Truelove and Witts Criteria determining severity of UC, what is considered severe?
Motions: \>6 PR bleed: large temp: \>37.8 HR: \>90 Hb \<10.5 ESR \> 30
123
In Truelove and Witts Criteria determining severity of UC, what is considered moderate?
Motions 4-6 PR bleed: moderate Temp: 37.1-37.8 HR 70-90 Hb 10.5-11
124
In Truelove and Witts Criteria determining severity of UC, what is considered mild?
Motions: \<4 PR bleed: small Temp: apyrexic HR \<70 Hb \>11 ESR \<30
125
Mx of acute severe UC?
resus: admit, IV fluids, NBM Hydrocotrisone IV 100 mg QDS Transfuse blood if required Thromboprophylaxis: LMWH Monitor bloods (FBC, ESR, CRP, U+E), vitals + stool chart, twice daily examination +/- AXR
126
acute complications of Severe UC?
perforation bleeding toxic megacolon (\>6 cm) VTE
127
mx of acute severe UC with improvement on IV hydrocortisone?
switch to oral pred + a 5-ASA taper pred after full remission
128
mx of acute severe UC w no improvement on IV hydrocortisone?
On day 3: stool freg \>8 or CRP \>45 - \> predicts 85% chance of needing a colectomy during the admission medical: ciclosporin, infliximab surgical: subtotal colectomy
129
1st line therapies in inducing remission in ulcerative colitis?
1st line: 5-ASAs 2nd line: prednisolone
130
medication for Maintaining remission in UC?
1st line: 5-ASAs PO- sulfasalazine or mesalazine (topical tx may be used in proctitis) 2nd line: azathioprine or mercaptopurine 3rd line: infliximab/ adalimumab
131
indications for emergency surgery in UC?
toxic megacolon perforation massive haemorrhage failure to respond to medical tx
132
AXR findings SBO vs LBO?
diameter: SBO ≥3 cm LBO ≥ 6cm (Caecum ≥ 9cm) Location: SBO- central LBO- peripheral SBO: valvulae conniventes LBO: haustra SBO: many loops LBO: few
133
Mx of Bowel obstruction?
Resus: NBM IV fluids NGT: decompress upper GIT, stops vomiting, prevents aspiration catheterise: monitor UO analgesia antibiotics: cef n met if strangulation or perf gastrograffin study: oral or via NGT consider need for parenteral nutrition non operative mx sucessful in 80% of pts w SBO w/o peritonitis otherwise: surgery
134
indications for elective surgery of ulcerative colitis?
chronic symptoms despite medical therapy carcinoma or high grade dysplasia
135
what surgeries are done electively for UC?
panproctocolectomy w end ileostomy or IPAA (ileal pouch anal anastomosis) or total colectomy w Ileal rectal anastomosis
136
UC surgical complications?
abdo: SBO (adhesions), anastomotic stricture, pelvic abscess Stoma: retraction, stenosis, prolapse, dermatitis Pouch: pouchitis, faecal leakage
137
ix (diagnostic) of Crohns?
ileocolonoscopy + regional biopsy
138
ix of Crohns duriing a severe attack?
high temp, raised HR, high CRP+ ESR, high WCC, low albumin
139
what blood results are severity markers of crohns?
FBC: low Hb, high WCC LFT: low albumin raised CRP/ESR
140
mx of Severe attack of Crohns?
resus: admit, NBM, IV fluids Hydrocortisone IV + PR if rectal disease ABx: metronidazole PO or IV thromboprophylaxis: LMWH Dietician review: elemental diet, consider parenteral nutrition monitoring: vitals, stool chart, daily exam
141
following mx if improvement following IV + PR hydrocortisone in severe attack of crohns?
Switch to oral prednisolone (40mg/ day)
142
following mx if no improvement following IV + PR hydrocortisone in acute severe attack of Crohns?
discussion between pt, physician and surgeon medical: methotrexate +/- infliximab surgical
143
inducing remission in mild / mod Crohns disease?
supportive: high fibre diet, vitamin supplements Oral: 1st line - ileocaecal: budesonide - colitis: sulfsalazine 2nd line: prednisolone (tapering) 3rd: methotrexate 4th: infliximab or adalimumab
144
maintaining remission in Crohns?
1st line: azathioprine or mercaptopurine 2nd: methotrexate 3rd: infliximab/ adalimumab
145
indications for surgery in Crohns?
emergency: failure to respond to medical tx intestinal obstruciton/ perforation massive haemorrhage elective: abscess or fistula perianal disease chronic ill health carcinoma
146
what surgical procedures are carried out in Crohns disease?
limited resection e.g. ileocaecal stricturoplasty (alleviate bowel narrowing due to scar tissue) defunction distal disease w temporary loop ileostomy
147
complications of surgery in crohns?
stoma complications enterocutaneous fistula anastomotic leak or stricture
148
features of short gut?
\<1 -2m small bowel steatorrhoea ADEK and B12 malabsorption bile acid depletion -\> gall stones hyperoxaluria -\> renal stones
149
definition of diverticulum?
outpouching of tubular structure true = composed of complete wall e.g. Meckels false = composed of mucosa only (pharyngeal, colonic)
150
definition of diverticular disease?
symptomatic diverticulosis
151
definition of diverticulitis?
inflammation of diverticula
152
pathophysiology of diverticular disease?
assoc w raised intraluminal pressure (low fibre diet) mucosa herniates through muscularis propria at points of weakness where perforating arteries enter most commonly in sigmoid colon commoner in obese pts
153
features of diverticular disease?
altered bowel habit left sided pain /colic relieved by defecation nausea flatulence
154
mx of diverticular disease?
high fibre diet, mebeverine (relaxing gut muscles) may help elective resection for chronic pain
155
presentation of diverticulitis?
faeces -\> obstruction of diverticulum abdo pain and tenderness - typically LIF - localised peritonitis pyrexia
156
ix in diverticulitis?
Bloods: WCC, CRP/ESR, Amylase, G+S/x match Imaging: erect cxr- look for perforation AXR- fluid level/ air in bowel wall contrast CT gastrograffin enema endoscopy: flexi sig, colonoscopy (not in acute attack -\> can perf)
157
Mx of acute diverticulitis?
if mild: treat at home w bed rest (fluids only) and augmentin +/- metronidazole admit if unwell, fluids not tolerated, pain uncontrolled Medical: NBM, IV fluids, analgesia, antibiotics: cef n met most cases settle if not, Surgery: Hartmanns to resect diseased bowel
158
indications for surgery in acute diverticulitis
perforation large haemorrhage stricture -\> obstruction
159
Surgical mx of Acute Diverticulitis?
Hartmann's procedure: surgical resection of the rectosigmoid colon w closure of the anorectal stump and formation of end colostomy (in emergency, immediate anatomosis is not possible)
160
complications of diverticulitis?
perforation: sudden onset pain, generalised peritonitis and shock haemorrhage: sudden, painless bright red PR bleed abscess: swinging fever, localising signs fistulae strictures
161
mx of perforation in acute diverticulitis?
hartmanns
162
mx of haemorrhage in acute diverticulitis?
usually stops spontaneously may need transfusion colonoscopy +/- diathermy/ adrenaline embolisation resection
163
mx of abscess in acute diverticulitis?
abx + CT/ US guided drainage
164
features of colovesicular fistulae?
pneumaturia intractable UTIs tx: resection
165
mx of strictures following acute diverticulitis?
resection stenting
166
commonest cause of SBO?
adhesions: 60% hernias
167
commonest causes of LBO?
colorectal neoplasia: 60% diverticular stricture: 20% volvulus: 5%
168
types of bowel obstruction?
**simple**: 1 obstructing point + no vascular compromise may be partial or complete **closed loop:** bowel obstructed @ 2 points - volvulus - competent ileocaecal valve - \> gross distension -\> perforation **strangulated**: compromised blood supply localised constant pain + peritonism fever + raised WCC
169
paralytic ileus may occur when?
usually small bowel ileus post op peritonitis pancreatitis poisons/ drugs e.g. TCAs metabolic: low K, Na, mg, uraemia mesenteric ischaemia
170
causes of mechanical bowel obstruction?
**intraluminal:** impacted matter: faeces, worms intussusception gallstones **intramural:** benign stricture (IBD, surgery, diverticulitis, radiotx) neoplasia congenital atresia **extramural:** hernia adhesions volvulus extrinsic compression: tumour, abscess, haematoma, pseudocyst, congenital bands (e.g. Ladd's)
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features of bowel obstruction?
colicky abdo pain distension: increases w lower obstructions vomiting: early in high obstruction, late or absent in low obstructions absolute constipation: no faeces or flatus
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examination of bowel obstruction?
fluid status fever surgical scars hernias mass: neoplastic/ inflammatory bowel sounds: increased / tinkling in mechanical obstruction decreased in ileus
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imaging in bowel obstruction?
erect CXR: free air AXR: bowel obstruction CT: can show transition point Gastrograffin studies: look for mechanical obstruction follow through may relieve mild mechanical obstruction: usually adhesional
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Bloods in Bowel obstruction?
FBC: raised WCC U+E; dehydration, electrolyte abnormalities Amylase: raised if strangulation/ perforation VBG: raised lactate in strangulation G+S/ clotting: may need surgery
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indications for surgical treatment of bowel obstruction?
closed loop obstruction obstructing neoplasm strangulation/ perforation -\> sepsis, peritonitis failure of conservative mx (up to 72h)
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surgical procedures for SBO?
adhesiolysis
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surgical procedures for LBO?
Hartmann's Colectomy + primary anastomosis Palliative bypass procedure tranverse loop colostomy or loop ileostomy caecostomy
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Sigmoid volvulus (80% of volvulus) - \> characteristin inverted U/ Coffee bean sign - long mesentery w narrow base predisposes to torsion
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presentation of sigmoid volvulus?
often elderly, constipated, co morbid pts assoc w neuropsych conditions e.g. parkinsons, schizophrenia massive distension w tympanic abdomen
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AXR signs of sigmoid volvulus?
coffee bean / inverted U sign
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Mx of sigmoid volvulus?
often relieved by sigmoidoscopy and flatus tube insertion -\> monitor for signs of bowel ischaemia following decompression sigmoid colectomy occassionally required -\> when failed endoscopic decompression/ bowel necrosis often recurs -\> elective sigmoidectomy may be needed
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Caecal volvulus kidney bean sign assoc w adhesions
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mx of caecal volvulus
only 10% of pts can be detorsed w colonoscopy -\> typically requires surgery right hemicolectomy w primary ileocolic anastomosis caecostomy
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features of gastric volvulus?
triad of gastro-oesophageal obstruction: vomitng -\> retching w regurgitation of saliva pain failed attempts to pass an NG tube
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risk factors for gastric volvulus?
congenital: bands, rolling/ paraoesophageal hernia, pyloric stenosis acquired: gastric/ oesophageal surgery adhesions
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Ix of gastric volvulus?
Xray shows gastric dilatation and double fluid level on erect films
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Mx of gastric volvulus?
endoscopic manipulation emergency laparotomy
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presentation of paralytic ileus?
adynamic bowel secondary to absence of normal peristalsis usually SBO reduced or absent bowel sounds mild abdo pain: not colicky
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prevention of paralytic ileus?
decreased bowel handling laparoscopic approach peritoneal lavage after peritonitis unstarched gloves
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mx of paralytic ileus?
conservative drip and suck mx correct any underlying causes: e.g. drugs, metabolic abnormalities consider need for parenteral nutrition exclude mechanical cause if protracted
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What is Ogilvie's syndrome?
Colonic Pseudo obstruction acute dilation of the colon in the absence of any mechanical obstruction in severely ill patients. massive dilatation of the cecum (diameter \> 10 cm) and right colon on abdominal X-ray.
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cause of colonic pseudo-obstruction?
aetiology unknown assoc w: elderly cardioresp disorders pelvic surgery e.g. hip arthoplasty trauma
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Mx of colonic pseudo-obstruction?
neostigmine: anticholinesterase colonoscopic decompression: 80% successful
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types of colonic adenomas?
colonic adenomas are benign precursors to colorectal cancer characterised by dysplastic epithelium **tubular:** small, pedunculated tubular glands **villous:** large, sessile, covered by villi **tubulovillous**: mixture
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presentation of colonic adenomas?
typically asymptomatic large polyps can bleed -\> IDA villous adenomas can -\> low K+ and hypoproteinaemia
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what increases the malignant potential of a colonic adenoma?
large size large amount of dysplasia increased villous component
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what gene mutation is assoc w colorectal cancer?
APC gene oncogene also kras p53
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other risk factors for colorectal cancer?
diet: low fibre, high refined carb IBD Familial: FAP, HNPCC, Peutz Jeghers Smoking Genetics NSAIDs/ Aspirin: protective
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most common type of colon cancer?
95% adenocarcinoma most commonly in rectum 35% then sigmoid 25%
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You are a new Foundation Year 1 (FY1) doctor working on a colorectal surgery ward and notice many patients are having post-operative analgesia given via an epidural. What is the main benefit of this form of analgesia compared to alternative forms?
faster return of normal bowel function
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presentation of colon cancer?
altered bowel habit PR bleeding/ mucus tenesmus PR mass obstruction right sized mass: anaemia, weight loss
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examination of colon cancer?
abdo exam: palpable mass/ hepatomegaly/ signs of obstruction PR exam: mass, perianal fistulae
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What tumour marker is most assoc w colorectal ca?
CEA carcinoembryonic antigen
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what imaging is required in pt diagnosed w colorectal ca?
CT chest abdo pelvis for complete staging Entire colon should be evaluated w colonoscopy or CT colonography those w tumours pelow the peritoneal reflection should have their mesorectum evaluated w MRI
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ix for suspected colorectal ca?
Bloods: FBC- Hb LFTs- Liver mets Tumour marker - CEA Imaging: CXR, US liver- mets CT and MRI- staging Ba/ gastrograffin enema - apple core lesion endoscopy + biopsy: flexi sig/ colonosocopy
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staging of Colon cancer?
Dukes criteria A: confined to bowel wall B: through bowel wall but no LNs C: regional LNs D: distant mets
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TNM staging of colon cancer?
TIS: carcinoma in situ T1: submucosa T2: muscularis propria T3: subserosa T4: through the serosa to adjacent organs N1: 1-3 nodes N2: \>4 nodes Grading: low to high based on cell morphology. dysplasia, mitotic index, hyperchromatism
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Mx of colon cancer?
MDT surgical resection of cancer - tailored to tumour location -\> + resection of supplying lymphatic chains (which follows arterial supply) or palliation: stents, surgical bypass, diversion stomas then chemotx
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prior to surgery for colon ca- what advice?
preop bowel prep (except R sided lesions) e. g. Kleen Prep (Macrogol: osmotic laxative) the day before and phosphate enema in the AM consent: discuss stomas stoma nurse consult for siting
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what is required for anastomosis to heal?
adequate blood supply mucosal apposition no tissue tension surrounding sepsis, unstable pts and inexperienced surgeons may compromise these key principles -\> may be safer to construct end stoma rather than attempting an anastomosis
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Mx of Rectal Cancer?
MDT Surgeries: Anterior resection or APR (Abdomino-perineal excision of rectum) + total mesorectal excision (meticulous dissection of mesorectal fat and LNs) for tumours of the middle and lower third Neo-adjuvant radio therapy to decrease local recurrence
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w rectal ca, when do you decide to anterior resection vs Abdominoperineal excision of the rectum?
APR: involvement of the sphincter complex or v low tumours (ie. \<4 cm from anal verge)
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What type of resection and anastomosis is required for cancer in caecum, ascending or proximal transverse colon?
Right hemicolectomy w ileocolic anastomosis
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what type of resection and anastomosis is required for cancer in distal transverse and descending colon?
Left hemicolectomy w colo-colon anastomosis
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what type of resection and anastomosis is required if cancer is in the sigmoid colon?
high anterior resection w colo-rectal anastomosis
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what type of resection and anastomosis is required in cancer in the upper rectum?
anterior resection with total mesorectal excision and a colo-rectal anastomosis
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what type of resection and anastomosis is required in pt w cancer in low rectum?
anterior resection with low total mesorectal excision and a colorectal anastomosis +/- defunctioning stoma
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what type of resection and anastomosis is recommended for pt w ca in anal verge?
abdominoperineal excision of rectum no anastomosis
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is anastomosis of colon done in the emergency setting?
no in emergency setting e.g. when bowel has perforated the risk of anastomosis is much greater, particularly when anastomosis is colon-colon end colostomy safer and can be reversed later resection of sigmoid colon+ end colostomy = Hartmanns procedure
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what screening is available for colorectal cancer?
60-75 yrs home faecal occult blood testing every 2 yrs (2% false positive) colonoscopy if FOB +ve
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what is familial adenomatous polyposis?
autosomal dominant APC gene on 5q21 100-1000s of adenomas by 16 yrs - mainly in large bowel - also affects stomach and duodenum 100% develop colorectal cancer
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what is attenuated FAP?
\<100 adenomas Colorectal ca later in life (\>50 yrs)
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What is Gardener's syndrome?
subtype of FAP will lead to colorectal cancer also TODE Thyroid tumours Osteomas of the mandible, skull and long bones Dental abnormalities: supernumerary teeth epidermal cysts
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what is Turcot's syndrome?
assoc w FAP/ HNPCC characterised by multiple adenomatous colon polyps + CNS tumours: medullo and glioblastomas
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mx of Familial adenomatous polyposis?
prophylactic colectomy before 20 yrs total colectomy + ileorectal anastomosis -\> requires life long stump surveillance proctocolectomy + ileal pouch-anal anastomosis risk of ca in stomach and duodenum remain -\> regular endoscopic screening
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What is hereditary non polyposis colorectal cancer?
autosomal dominant commonest cause of hereditary colorectal cancers assoc with gastric, endometrial, prostate, breast, ovarian ca
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dx of HNPCC?
321 rule ≥3 family members over 2 generations w one \< 50 yrs
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in patients w fulminant UC, why is the rectum not taken out during emergency surgery?
subtotal colectomy is safest tx option rectum is left in situ as resection of the rectum in these acutely unwell patients carries an extremely high risk of complications -\> if bowel is v oedematous, may be brought to surface as mucous fistula
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mx of severe perianal and or rectal crohns?
proctectomy - ileoanal pouch reconstruction in crohns carries a high risk of fistula formation and pouch failure and is not recommended
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what is Peutz Jeghers syndrome?
autosomal dominant mucocutaneous hyperpigmentation - on palms, buccal mucosa multiple GI hamartomatous polyps -\> increased risk of haemorrhage, intussusception increased ca risk of colorectal ca, pancreas, breast, lung, ovaries, uterus
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causes of acute mesenteric ischaemia?
arterial: thrombotic (35%), embolic (35%) non occlusive: splanchnic vasoconstriction secondary to shock venous thrombosis trauma, strangulation, vasculitis
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presentation of mesenteric ischaemia?
nearly always small bowel triad: 1. acute severe abdo pain +/- PR bleed 2. rapid hypovolaemia -\> shock 3. no abdo signs degree of illness \>\> clinical signs may be in AF
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ix of mesenteric ischaemia?
bloods: high Hb: plasma loss high WCC high amylase persistent metabolic acidosis: raised lactate imaging: AXR- gasless abdo arteriography/ CT/MRI angio
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complications of mesenteric ischaemia?
septic peritonitis SIRS
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mx of mesenteric ischaemia?
fluids abx: gent + met LMWH laparotomy: resect necrotic bowel
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ileostomy vs colostomy stoma?
small bowel stomas should be spouted so that their irritant contents are not in contact with the skin usually more high output than colonic stomas colonic stomas: flat
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cause of chronic small bowel ischaemia?
atheroma + low flow state e.g. LVF
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features of chronic small bowel ischaemia?
severe, colicky post prandial abdo pain 'gut claudication' PR bleeding malabsorption weight loss
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what is a mucous fistula?
To decompress a distal segment of bowel following colonic division or resection Where closure of a distal resection margin is not safe or achievable
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mx of chronic small bowel ischaemia?
angioplasty
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features of chronic large bowel ischaemia?
lower, left sided abdo pain bloody diarrhoea pyrexia tachycardia
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ix of chronic large bowel ischaemia?
raised WCC barium enema: thumb printing MR angiography
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complications of chronic large bowel ischaemia?
may -\> peritonitis and septic shock strictures in the long term
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mx of chronic large bowel ischaemia?
usually conservative: fluids, abx angioplasty and endovascular stenting
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causes of lower GI bleed?
rectal: haemorrhoids, fissure diverticulitis neoplasm inflammation: IBD infection polyps large upper GI bleed angio: dysplasia, ischaemic colitis, HHT
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1st line ix for lower GI bleed?
1st: rigid proctoscopy/ sigmoidoscopy 2nd: OGD
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mx of lower GI bleed?
resus abx: if evidence of sepsis or perf PPI: if upper GI bleed possible keep bed bound stool chart diet: keep on clear fluids surgery: only if unremitting, massive bleed
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role of CEA in colorectal ca?
used to monitor for recurrence in patients post-operatively or to assess response to treatment in patients with metastatic disease
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most common type of anal ca?
80% are SCC
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ix of angiodysplasia?
exclude other dx: PR exam, barium enema, colonoscopy mesenteric angiography or CT angio Tc labelled RBC scan: identify active bleeding
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mx of angiodysplasia?
embolisation endoscopic laser electrocoagulation resection
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