Gastro Flashcards
Gastric CA RF
Modifiable
- lifestyle: diet (preserved, smoke, nitrosamine), smoking
- low SES
- chronic gastritis, prev H pylori, barrett esophagus
- prev OGD: polyp
- prev stomach lymphoma
- smoking
- obesity
- atrophic gastritis
- pernicious anemia
- Menetrier dz (hypertrophic gastropathy)
Non modifiable
- age >50
- gender: males
- previous gastric resection (partial gastrectomy with bile reflux)
- type A blood
- family history
- familial diffuse gastric cancer (e-cadherin, CDH 1)
- FAP (Apc gene), HNPCC/ Lynch syndrome, BRCA1/2, PJS, Li-Fraumeni syndrome
- common variable immune deficiency (CVID)
protective factors: aspirin, fresh fruits/ vegetables, vit C
Forrest classification
Acute hemorrhage Ia: spurting Ib oozing Signs of recent hemorrhage IIa: non bleeding visible vessel IIb: adherent clot IIc: flat pigmented spot no active bleed: III: clean ulcer base
Prognostication for acute UGI bleed
Rockall Blatchford AIMS 65 - Albumin <30 - INR >1.5 - Mental state GCS<14 - SBP <90 - age >65
CLO positive?
- treatment of H pylori
- test for eradication
Clostridium like organism: urease producing org that cleaves urea to ammonia and HCO3, decreasing the PH (yellow > red)
H pylori tx: TRIPLE THERAPY
- amoxicillin (1g BD) 2w
- clarithromycin (500mg BD) 2w
- omeprazole 6w
sub amox for metronidazole only in penicillin allergic individuals
BISMUTH QUAD THERPAY
- omeprazole 20mg BD
- bismuth subsalicylate (120mg QDS)
- 2 Abu: metronidazole 400mg BD + tetracycline 500mg QDS
ERADICATION TESTS
- urea breath test
- fecal antigen test
- OGD >4w after completion of abx therapy (PPI withheld 1-2w prior to testing)
Indications for repeat endoscopy for gastric ulcers
surveillance endoscopy after 12w of antisecretory therapy if gastric ulcer with
- symptoms despite med therapy
- unclear etiology
- giant ulcer >2cm
- presented with bleeding
- RF for gastric ca
- first endoscopic shows suspicious ulcer
- biopsies not taken in first endoscopy
Definition of orthostatic hypotension
a decrease in the systolic blood pressure of more than 20 mmHg and/or an increase in heart rate of 20 beats per minute when moving from recumbency to standing
ddx UGBIT
variceal - GEJ non variceal - eso: mallory weiss - gastric: PUD, gastritis, dieulafoy - duodenum: duodenitis, aorto-enteric fistula
classes of shock
I: <15%
II: 15-30%: resting tachycardia, urine output 20-30, decreased pulse pressure, orthostatic hypotension
III: 30-40%: resting hypotension, anxious, urine 5-15, tachypnea
IV: >40%: negligible urine output, confused lethargic
Indications for emergency OGD
- role of OGD
- shock/ hemodynamic instability
- active BGIT (hemetemesis, fresh Malena)
- suspected variceal bleed
diagnostic - confirm UGBIT, identify source of bleed, biopsy (clo + 6 bites for gastric ulcer)
therapeutic: stop bleed
prognostic: forest classification
Types of gas used to scopes and differences
types of gas infused
- CO2: need more vol to distend bowel but body can resorb
- air (more nitrogen): not absorbed by mucosa, helps distend bowel with less volume, but more problems if perforated bowel - cannot be resorbed by body
complications of OGD
Anesthetic risk - sedation: resp depression - CVS risk - ami, cva Procedural related risk - bleeding and perforation - failure of endoscopic hemostasis - failure of complete scope
Mgx of rebleeding of UGBIT
repeat OGD and endoscopic hemostasis
if fail:
- surgery
- radio: CTMA or mesenteric angiogram KIV embolisation
Prognostication for UGBIT
Rockall score
Blatchford scoring
AIMS 65: albumin <30, INR >1.5, Mental status <14, SBP<90, age>65
Hepatic venous pressure gradient
- normal value
- risk of variceal devt
- risk of variceal bleed
n: 1-5mmhg
devt: >10mmhg
bleed/ ascites: >12
What is Zollinger Ellison syndrome?
- how to diagnose
- how to mgx?
hyper secretion of gastric acid due to a gastrinoma (rare cause of PUD)
triad of: recurrent PUD in unusual locations, massive gastric acid hyper secretion, gastrinoma
dx: high fasting serum gastrin levels with high acid secretion
mgx: PPI + sx
Endoscopic methods of stopping bleeding
- injection of adrenaline 1:10,000 dilute to 10ml (cx: perforation, bleed, necrosis, arrhythmia)
- coagulation (heater probe - thermal/ argon plasma)
- haemostatic clipping (endocrine clip), hemospray
dual modality
sx management of duodenal ulcers
- truncal vagotomy with pyloroplasty
- truncal vagotomy with antrectomy and bilroth 1/2
- highly selective vagotomy
options for gastric ulcer bleeding refractory to endoscopic therapy
transcatheter arterial embolisation (TAE)
surgical: oversewing of bleeding vessels/ wedge excision of ulcer
DU posterior: GD artery
Causes of pneumoperitoneum
suggestive of perforated viscus: GU, DU, appendix, GB
sx mgx of perf gastric/ duodenal ulcer
Duodenal:
lap omental patch repair
peritoneal debridement/washout
H pylori eradication
Gastric:
wedge excision - TRO CA
if perf too big > gastrectomy (bilroth II) or serial patch/ mental patching
mgx of gastric outlet obstruction
correct volume/ electolytes
NG suction
IV antisecretory agents
OGD
endoscopic hydrostatic balloon dilatation
surgical if recurrent/ refractory after endo balloon
- antrectomy with bilroth I/II reconstruction
OGD classification of gastric cancer
Borrmann classification I: polypoid/ protruded type II-V: depressed type 2 ulcerative 3 infiltrative ulcerative 4 diffuse infiltrative aka linitis plastica (signet ring cells) 5 can't be classified
Classification of biopsy findings in gastric ca
Adenocarcinoma (Lauren classification)
- intestinal (expanding): elderly male, distal stomach, GOO, hematogenous spread
> papillary
> tubular
> mucinous
- diffuse (infiltrative): signet cell, younger, female, proximal stomach, transmural and lymphatic spread with early mets, CDH1 mutation (E-cadherin)
Non-adenoCA
- gastric neuroendocrine tumour (carcinoid)
- gastric lymphoma
- gastrointestinal stomal tumour
what are signet ring cells
large cytoplasmic mucin vacuoles and peripherally displaced crescent shaped nuclei
what is carcinoid syndrome?
due to release of vasoactive substances into systemic circulation
Characterized by cutaneous flushing, sweating, bronchospasm, colicky abdominal pain, diarrhoea, right-sided cardiac valvular fibrosis
suggestive of mets, if localised in GIT should not have systemic effects due to first pass from liver
What are carcinoids?
gastric neuroendocrine tumour
derived from: enterochromaffin like cells in gastric mucosa
due to: hypergastrinoma (Zollinger-Ellison syndrome, MEN 1)
look for carcinoid syn - mets
What is gastric lymphoma
B cell lymphoma - extra nodal MALT type (mucosal Assoc lymphoid tissue)
- lymphocytes in gastric mucosa
- etiology: H pylori chronic gastritis, trisomy 3
What is GIST?
how to tx
are they malignant?
gastrointestinal stromal tumour
from: interstitial cells of cajal
etiology: c-KIT (gain of function mutation), PDGFRA (plt derived growth factor receptor alpha) mutation
c-KIT positive (95%): treat with imatinib (Tyrosine kinase inhibitors)
3/4 benign indicators of malignancy: - size > 10cm - mitotic index >5/10hpf - site (extra gastric position)
lab results of iron deficiency anemia
low ferritin, low serum fe, high transferrin, high TIBC
examples of paraneoplastic syndromes
- trousseau syndrome (migratory thrombophlebitis)
- DVT
- leser trelat sign (acute seborrheic keratosis)
signs of peritoneal seeding of gastric cancer
- ascites (peritoneal carinomatosis), may present as small bowel obstruction
- sister Mary Joseph nodule
- krukenburg tumour
- fullness in pelvic cul-de-sac (blumer shelf) on DRE
Classification of esophagogastric junction tumours (adenoCA)
Siewert classification
I: distal eso (1-5cm above gastric cardia)
II: 1cm above to 2cm below gastric cardia
III: subcardial, 2-5cm below gastric cardia
Curative mgx of gastric ca
Early Ca: endoscopic mucosal resection or endoscopic submucosal dissection
patient optimisation: nutrition support
neoadjuvant chemo
- wide resection (>6cm margins): partial, subtotal and total gastrectomy
- resection of LN and involved structures (D2 lymphadenectomy)
- re-establish GI continuity (reconstruction: bilrothI Gastroduodenostomy)/II (gastrojejunostomy), roux en y)
- adjuvant chemo
what is the difference between total, subtotal and partial gastrectomy
total: excision of whole stomach, 1st part duodenum, distal eso and all vessels (RGA, LGA, RGeA, LGeA, short gastric arteries)
subtotal: leaves proximal part of stomach for anastomosis to jejunum and has better residual reservoir function. keeps short gastric arteries
partial: distal stomach + RGA + RGeA
Complications of gastrectomy
Early
- bleed/ infection
- injury to surrounding organs
- anastomotic leak (d5-7)
- duodenal stump blowout (d5-7)
Late
- early satiety
- dumping syndromes (early/ late)
- nutritional deficiency (loss of intrinsic factor - b12, less gastric acid to convert Fe3 to Fe2, less iron absorption into terminal ileum
- loop syndromes
- retained antrum syndrome
- intestinal hurry
- biliary reflux into stomach
- recurrence of gastric ca
Gastric ca tumour markers
CEA and CA125
Gastric cell types and secretions
Parietal cells: HCL, intrinsic factor Chief cells: pepsinogen, gastric lipase G cells: Gastrin ECL cells: histamine Mucus neck cells: mucus and HCO3 D cells: somatostatin
antrum: G cells
body: parietal cells
Evidence of trans-coelomic spread (peritoneal seeding)
- ascites/ SBO (peritoneal carcinomatosis)
- umbilical infiltration (sister Mary Joseph)
- enlarged ovaries (krukenburg tumor)
Fullness in pelvic cul-de-sac (blumer shelf)
gene mutations in
- HNPCC
- FAP
- PJS
- Li-Fraumeni
- HNPCC: DNA mismatch repair genes (MLH1, MSH2, MSH6, PMS2) or EPCAM gene
- FAP: APC gene
- PJS: STK1
- Li-Fraumeni: TP53
