Lower GI Surgery Flashcards
define Meckel’s diverticulum and its common features, just FYI
Meckel’s Diverticulum
• Ileal remnant of vitellointestinal duct
§ Joins yoke sac to midgut lumen
Features
• A true diverticulum
• 2 inches long
• 2 ft from ileocaecal valve on antimesenteric border
• 2% of population
• 2% symptomatic
• Contain ectopic gastric or pancreatic tissue
presentation of sympto Meckel’s diverticulum
rectal bleeding
appendicitis mimic
intuss/volvulus
symptoms triggered by gastric secretions in wrong place
inv and management Meckel’s
nothing if no signs
technecium scan identifies most
resect diverticulum
intussusception
6-12 months, colicky abdo pain bowel invaginated into itself bilious vomiting inconsolable crying redcurrant jelly stools sausage-shaped mass
management intussusception
resus, x match, NGT
air enema + USS
surgery if air not worked
*rarely occurs in adults, if so, exclude cancers
mesenteric adenitis
viral infection / URTI triggers enlargement of LNs in mesentery
generalised pain + fever + tenderness
lymphocytosis
appendix mimic
presentation bowel cancers
nausea, vomiting, obstructed
weight loss, abdo pain
bleeding
jaundice if obstructed / metastasis
do AXR, CT
bowel cancers distribution
1/3 benign - polyp, haemangioma etc
2/3 malignant - adenocarcinoma, carcinoid
carcinoid tumour presentation
may present as blockage etc
otherwise:
Flushing: paroxysmal, upper body ± wheals
• Intestinal: diarrhoea
• Valve fibrosis: tricuspid regurg and pulmonary stenosis
• whEEze: bronchoconstriction
• Hepatic involvement: bypassed 1st pass metabolism
• Tryptophan deficiency → pellagra (3Ds)
investigating and treating carcinoid tumour
urine 5 HIA
plasma chromogranin A
CT/MRI
give octreotide/loperamide
resect very yellow tumour
carcinoid crisis
Vasodilatation, hypotension, bronchoconstriction,
hyperglycaemia
occurs with overhandling / outgrowing blood supply = dumping of mediators
give high dose octreotide to treat
DDx appendicitis
Surgical
§ Cholecystitis
§ Diverticulitis
§ Meckel’s diverticulitis
• Gynae
§ Cyst accident: torsion, rupture, haemorrhage
§ Salpingitis / PID
§ Ruptured ectopic
• Medical
§ Mesenteric adenitis
§ UTI
§ Crohn’s
appendicitis special signs o/e x 3
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
presentation of appendicits
colicky abdo pain gradually localised to RIF guarding anorexia nausea low grade fever obs off palpable RIF mass maybe
if pain on PR consider pelvic appendicitis
investigating ? appendicitis
- Dx is principally clinical
- Bloods: FBC, CRP, amylase, G+S, clotting
• Urine § Sterile pyuria: may indicate bladder irritation § Ketones: anorexia § Exclude UTI § β-HCG
• Imaging § US: exclude gynae path, visualise inflamed appendix § CT: can be used • Diagnostic lap
treating appendicitis
Fluids + resus
• Abx: cef 1.5g + met 500g IV TDS
• Analgesia: paracetamol, NSAIDs, codeine phosphate
• Certain Dx → appendicectomy (open or lap)
• Uncertain Dx → active observation
complications of appendicitis
perforation, abscess
UC pathology
rectum, colon, backwash ileitis
continuous
shallow broad inflammation
pseudopolyps
no fistulae, granulomas
Chron’s pathology
whole GI tract transmural skip lesions cobblestone inflammation strictures fibrosis granulomas fistulae
extra-intestinal manifestations IBD
commonest: clubbing e nodosum iritis arthritis
Skin
- Clubbing
- Erythema nodosum
- Pyoderma gang (esp. UC)
Eyes
- Iritis
- Conjunctivitis
- Episcleritis
- Scleritis
Joints
• Arthritis (non-deforming, asymmetrical)
• Sacroiliitis
• Ank spond
Hepatobiliary
• PSC + cholangiocarcinoma (esp. UC)
• Gallstones (esp. Crohn’s)
• Fatty liver
Other
• Amyloidosis
• Oxalate renal stones (esp. Crohns)
classic UC presentation
diarrhoea blood and mucus PR abdo discomfort tenesmus faecal urgency fever distended abdo
complications of UC
toxic megacolon (and consequent perf risk)
bleeding
malignancy
cholangiocarcinoma
strictures
venous thrombosis
classic Chron’s history and exam
non bloody diarrhoea
abdo pain
FTT in appearance
weight loss
aphthous ulcers, glossitis abdo tender RIF mass perianal abscess, fistula perianal tags anal, rectal strictures
complications of Chron’s
fistulae - can be into bladder / vagina, perianal ‘pepperpot anus’
strictures and obstruction
abscesses
malabsorption: of fat = steatorrhoea, gallstones of B12 = megalo anaemia vit D = osteomalacia protein = oedema
investigation findings in UC (at presentation)
buzzwords
• Bloods: § FBC: ↓Hb, ↑WCC § LFT: ↓albumin § ↑CRP/ESR § Blood cultures
• Stool
§ MCS: exclude Campylo, Shigella, Salmonella…
§ CDT: C. diff may complicate or mimic
faecal calprotectin
• Imaging § AXR: megacolon (>6cm), wall thickening § CXR: perforation § CT § Ba / gastrograffin enema § Lead-pipe: no haustra § Thumbprinting: mucosal thickening § Pseudopolyps: regenerating mucosal island • Ileocolonoscopy + regional biopsy: Baron Score
measuring severity of UC
Truelove criteria
depends on number of BO
fever
anaemia
bleeds etc
management acute attack of UC
• Resus: Admit, IV hydration, NBM • Hydrocortisone: IV 100mg QDS + PR • Transfuse if required • Thromboprophylaxis: LMWH • Monitoring § Bloods: FBC, ESR, CRP, U+E § Vitals + stool chart § Twice daily examination § ± AXR
managing acute attack of UC depending on progress
progress seen -> taper preds and move onto sulfa and oral steroid
no progress -> majority will require colectomy, can try aggressive Isuppression
maintaining UC remission
1st line: 5-ASAs PO – sulfasalazine or mesalazine
• 2nd line: Azathioprine or mercaptopurine
§ Relapsed on ASA or are steroid-dependent
§ Give 6-mercaptopurine if azathioprine intolerant
• 3rd line: Infliximab / adalimumab
surgery in UC
total /subtotal colectomy with end ileostomy
investigation findings in Chron’s (at presentation)
buzzwords
Bloods: (top 3 are severity markers) § FBC: ↓Hb, ↑WCC § LFT: ↓albumin § ↑CRP/ESR § Haematinics: Fe, B12, Folate § Blood cultures
• Stool
§ MCS: exclude Campylo, Shigella, Salmonella…
§ CDT: C. diff may complicate or mimic
faecal calprotectin
• Imaging § AXR: obstruction, sacroileitis § CXR: perforation § MRI § Assess pelvic disease and fistula § Assess disease severity § Small bowel follow-through or enteroclysis § Skip lesions § Rose-thorn ulcers § Cobblestoning: ulceration + mural oedema § String sign of Kantor: narrow terminal ileum • Endoscopy § Ileocolonoscopy + regional biopsy: Ix of choice § Wireless capsule endoscopy § Small bowel enteroscopy
managing severe Chron’s relapse
• Resus: Admit, NBM, IV hydration • Hydrocortisone: IV + PR if rectal disease • Abx: metronidazole PO or IV • Thromboprophylaxis: LMWH • Dietician Review § Elemental diet - Liquid prep of amino acids, glucose and fatty acids § Consider parenteral nutrition • Monitoring § Vitals + stool chart § Daily examination
oral therapy Chron’s
1st line
§ Ileocaecal: budesonide
§ Colitis: sulfasalazine
- 2nd line: prednisolone (tapering)
- 3rd line: methotrexate
- 4th line: infliximab or adalimumab
maintaining remission in Chron’s
1st line: azathioprine or mercaptopurine
• 2nd line: methotrexate
• 3rd line: Infliximab / adalimumab
short gut syndrome
following resections
• <1-2m small bowel • Features § Steatorrhoea § ADEK and B12 malabsorption § Bile acid depletion → gallstones § Hyperoxaluria → renal stones • Rx § Dietician § Supplements
why surgery in Chron’s?
Emergency
§ Failure to respond to medical Rx
§ Intestinal obstruction or perforation
§ Massive haemorrhage
• Elective § Abscess or fistula § Perianal disease § Chronic ill health § Carcinoma
Procedures
• Limited resection: e.g. ileocaecal
• Stricturoplasty
• Defunction distal disease ¯c temporary loop ileostomy
symptoms of diverticular disease
Altered bowel habit ± left-sided colic § Relieved by defecation • Nausea • Flatulence • Rx § High fibre diet, mebeverine may help (antispasmodic) § Elective resection for chronic pain
define diverticular disease
Mucosa herniates through muscularis propria at points
of weakness where perforating arteries enter. (=diverticulum)
• Most commonly located in sigmoid colon
disease = symptomatic
presentation diveriticulitis
Abdominal pain and tenderness
§ Typically LIF
§ Localised peritonitis
• Pyrexia
due to congealed stool, following hx of constipation
investigating diverticulitsi
Bloods § FBC: ↑WCC § ↑CRP/ESR § Amylase § G+S/x-match • Imaging § Erect CXR: look for perforation § AXR: fluid level / air in bowel wall § Contrast CT • Endoscopy § Flexi Sig § Colonoscopy: not in acute attack
grading system for diverticulitis
Hinchey
surgery only if peritonitic
management diverticulitis
mild - bowel rest and abx
admit if unwell + no oral intake + pain
management:
NBM, fluids, pain relief, abx
surgery if perf, bleed or blockage
procedure:
- Hartmann’s to resect diseased bowel
- May consider lap washout for Hinchey 3
signs of abdo abscess
swinging fever
v high WBCs
classify bowel obstructin
Simple
1 point only, no ischaemia
Closed Loop
2 point obstruction
can cause volvulus + perf
Strangulated
ischaemia, peritonism, fever, high WBCs
causes of small and large bowel obstruction
Small BO
• Adhesions: 60%
• Hernia
Large BO
• Colorectal Neoplasia: 60%
• Diverticular stricture: 20%
• Volvulus: 5%
causes of paralytic ileus
Post-op • Peritonitis • Pancreatitis or any localised inflammation • Poisons / Drugs: anti-AChM (e.g. TCAs) • Pseudo-obstruction • Metabolic: ↓K, ↓Na, ↓Mg, uraemia • Mesenteric ischaemia
categorising bowel obstruction
small vs large
mechanical vs non mech
classify mechanical causes of bowel obstruction
intraluminal - impacted faeces, gallstones, etc
intramural - strictures, cancers
extramural - hernia, adhesion, volvulus, extrinsic compression
presentation of bowel obstruction
central colicky abdo pain
(localised or constant pain suggests strangulated or impending perforation)
distension
vomiting more prominent in higher obstructions in bowel
absence of flatus or stool
investigations and findings bowel obstructions
Bloods
§ FBC: ↑WCC
§ U+E: dehydration, electrolyte abnormalities
§ Amylase: ↑↑ if strangulation/perforation
§ VBG: ↑ lactate in strangulation
§ G+S, clotting: may need surgery
• Imaging § Erect CXR § AXR: ± erect film for fluid levels § CT: can show transition point • Gastrograffin studies § Look for mechanical obstruction: no free flow § Follow through or enema § Follow through may relieve mild mechanical obstruction: usually adhesional
colonoscopy not used
o/e bowel obstruction
- ↑HR: hypovolaemia, strangulation
- Dehydration, hypovolaemia
- Fever: suggests inflammatory disease or strangulation
less BS with paralytic ileus, more in mechanical
AXR small vs large bowel obstruction
small bowel - central on film valvulae conniventes (completely across) many loops many short fluid levels no gas
large bowel -
peripheral on film
incomplete haustrae
gas present
*ileus has no clear transition point, both bowels may be visible
medical management bowel obstruction
NBM
aggressive fluids
NGT to decompress
catheterise and monitor
analgesia
abx
gastrograffin study
consider TPN
regular o/e
repeat bloods, imaging
SBO less likely to need surg
surgical management in bowel obstruction
if:
cons management failed over 72 hrs
cancer
sepsis, peritonism
closed loop obstruction
treat cause, resect
do stoma later
which type of volvulus is far more common?
sigmoid (vs caecal)
sigmoid volvulus risk factors
old constipated neuropsych conditions (MS,etc)
presentation / inv sigmoid volvulus
coffee bean sign AXR
massively distended abdo
hx of risk factors
management sigmoid volvulus
sigmoidoscopy+ flatus tube insertion to decompress
otherwise sigmoid colectomy and elective repair
caecal volvulus general info
usually due to congenital malform
not attached properly in RIF
usually need right hemi
signs of gastric volvulus
pain, vomiting, failed NGT insertion
inv and management gastric volvulus
double fluid level on erect film
risk factors
treat - endoscopic dilatation, laparatomy
preventing paralytic ileus
limit bowel handling
l’scopic approach
peritoneal lavage
treating paralytic ileus
drip and suck (horrible expression)
correct drugs or met derangement
colonic pseudo-obstruction
very distended proximal colon in an elderly person with non colic or mech obstruction
treat with neostigmine, abx, decompression
(can otherwise lead to necrosis +/- perf)
colonic adenomas
may present as iron deficiency anaemia from bleeds
or low potassium, low protein if villous adenoma
increasing risk of malignant transformation for an adenoma
↑ size
§ ↑ dysplasia
§ ↑ villous component
(can be tubular or mixed as well)
general genetic process in malignant colon polyp transformation
• First hit: mutation of one APC copy
• Second hit: mutation of second APC copy
§ → adenoma formation
• Additional mutations in adenoma → malignant
transformation: e.g KRAS, p53
risk factors with colon cancer
Diet: ↓ fibre + ↑ animal fat / protein
• IBD: CRC in 15% of those with pancolitis for 20yrs
• FH: FAP, HNPCC, Peutz-Jeghers
• Smoking
• Genetics - first degree relative with CRC = 1/10 risk
• NSAIDs / Aspirin (300mg/d): protective
most common colon cancer
95% adenocarcinoma
usually rectum or sigmoid
presentation left-sided colon cancer
- Altered bowel habit
- PR mass (60%)
- Obstruction (25%)
- Bleeding / mucus PR
- Tenesmus
presentation right-sided colon cancer
Anaemia
• Wt. loss
• Abdominal pain
less clear cut Dx
colon cancer o/e
- Palpable mass: per abdomen or PR
- Perianal fistulae
- Hepatomegaly
- Anaemia
- Signs of obstruction
investigations and findings with colon cancer
Bloods
FBC: Hb
LFTs: mets
Tumour Marker: CEA (carcinoembryonic Ag)
• Imaging CXR: lung mets US liver: mets CT and MRI - Staging - MRI best for rectal Ca and liver mets
Endoanal US: staging rectal tumours
Ba / gastrograffin enema: apple-core lesion
• Endoscopy + Biopsy
Flexi sig: 65% of tumours accessible
Colonoscopy
`staging, spread, grading colon cancer
Duke’s classification
TNM
cell properties - mitotic index etc
managing colon cancer
MDT staging CT/MRI surgery if appropriate deal with any anaemia, metabolic probs etc adjuvant chemotherapy
surgery for bowel cancer
Rectal: AP resection if <4cm from anal verge, anterior resection otherwise
Sigmoid: high anterior resection or sigmoid colectomy
- Left: left hemicolectomy
- Transverse: extended right hemicolectomy
- Caecal / right: right hemicolectomy
bowel cancer screening
55-60 yrs 1 x flexi sig
60-75 two yearly faecal occult blood testing
Familial Adenomatous Polyposis
develop 1000s of polyps by late teens
near guaranteed bowel ca sadly
prophylactic colectomy with regular surveillance of remaining GIT
Hereditary Non-Polyposis Colorectal Cancer (Lynch syndrome)
3% of all CRC
two types
Peutz-Jeghers Syndrome
only so aware
~ 10-15yrs • Mucocutaneous hyperpigmentation § Macules on palms, buccal mucosa • Multiple GI hamartomatous polyps § Intussusception § Haemorrhage • ↑ Ca risk § CRC, pancreas, breast, lung, ovaries, uterus
causes of mesenteric ischamia
Arterial: thrombotic (35%), embolic (35%)
• Non-occlusive (20%)
e.g. Splanchnic vasoconstriction - shock
- Venous thrombosis (5%)
- Other: trauma, vasculitis, strangulation
mesenteric isch triad
Acute severe abdominal pain ± PR bleed
§ Rapid hypovolaemia → shock
§ No abdominal signs
appear v ill, may have concomitant AF
investigations mes ischaemia
• Bloods § ↑Hb: plasma loss § ↑WCC § ↑ amylase § Persistent metabolic acidosis: ↑lactate
• Imaging
§ AXR: gasless abdomen
§ Arteriography / CT/MRI angio
management mesenteric ischaemia
Fluids
• Abx: gent + met
• LMWH
• Laparotomy: resect necrotic bowel
chronic small bowel ischaemia
Cause: atheroma + low flow state (e.g. LVF)
• Presentation: § Severe, colicky post-prandial abdo pain - “gut claudication” § PR bleeding § Malabsorption § Wt. loss • Mx: angioplasty
(‘abdo angina’)
chronic large bowel ischaemia signs symp
Cause: follows low flow in IMA territory • Presentation § Lower, left-sided abdominal pain § Bloody diarrhoea § Pyrexia § Tachycardia
inv and management chronic large bowel ischaemia
Ix
§ ↑WCC
§ Ba enema: thumb-printing
§ MR angiography
• Mx
§ Usually conservative: fluids and Abx
§ Angioplasty and endovascular stenting
causes of a lower GI bleed
Common / Important
• Rectal: haemorrhoids, fissure
• Diverticulitis
• Neoplasm
Other
• Inflammation: IBD
• Infection: shigella, campylobacter, C. diff
• Polyps
• Large upper GI bleed (15% of lower GI bleeds)
• Angio: dysplasia, ischaemic colitis, HHT
investigating lower GI bleeding
- Bloods: FBC, U+E, LFT, x-match, clotting, amylase
- Stool: MCS
• Imaging
AXR, erect CXR
Angiography (if no source on endoscopy)
Red cell scan (nuc medicine)
• Endoscopy
1st: Rigid proctoscopy / sigmoidoscopy
2nd: OGD
3rd: Colonoscopy: difficult in major bleeding
management lower GI bleed
ABCDE and resus catheter abx if sepsis or perf PPI if ?GI bleed bed bound as risk collapse stool chart clear fluids (colonoscopy) surgery only last resort
gut angiodysplasia just FYI
Submucosal AV malformations
• 70-90% occur in right colon
• Can affect anywhere in GIT
Presentation
• Elderly
• Fresh PR bleeding
Ix
• Exclude other Dx
§ PR exam
§ Ba enema
§ Colonoscopy
• Mesenteric angiography or CT angiography
• Tc-labelled RBC scan: identify active bleeding
Rx
• Embolisation
• Endoscopic laser electrocoagulation
• Resection
