Principles of Gastrointestinal Surgery Flashcards
what are the layers of the intestinal tract?**
- serosa
- muscular layers
- submucosa: strength from collagenous fibers, holding layer, integrity from vascular plexi
- mucosa: absorptive and secretory functions
what is the holding layer of the intestinal tract?***
submucosa
how can you determine intestinal viability?
- bowel color
- presence or absence of peristalsis
- bleeding from cut edge of bowel (normal, want to see)
- presence or absence of mesenteric artery pulsation
surface oximetry to determine intestinal viability?***
- PsO2 > 50% of normal baseline
(oximeter and measuring surface tension of bowel and seeing what it looks like) - can only assess small areas of bowel at a time
doppler ultrasonography to determine intestinal viability?
- measure arterial blood flow at the antimesenteric surface; if arterial signals present, the bowel is likely viable
- best for straight venous obstruction
what is the best method (questionable in horses) of determining intestinal viability?
- sodium fluorescein dye
- IV, fluorescence under long wave UV: wood’s lamp
- viable if hyperemic, normal/fine granular pattern present
- non viable if patchy, perivascular or non-fluorescent pattern present
how else can you look at intestinal viability?
- frozen section
- histopathology
needs reliable pathologist!
what is the strength of bowel 0-4 days after sx
suture provides only strength
what is the bowel strength 4-5 days after sx
inflammatory stage: very little strength
what is the bowel strength 7-21 days after sx?
fibroblastic stage: rapid gain in strength
what is the bowel strength 21+ days after sx?
remodeling stage: slow increase in strength
when does bowel anastomosois fail?
- at anastomosis within first 7 days- need suture that lasts in bowel at LEAST 7 days!!
- through unwounded intestinal wall after 7 days
when do you need the most suture strength?
between 0 and 7 days
what suture patterns affect adhesion formation?
everting > appositional > inverting
higher incidence with interrupting
what suture pattern is least likely cause adhesions?
inverting
when do sutures dissolve in water?
chromic gut: never
dexon: 15 days
vicryl: 12 days
what is the only suture that dissolves in GI contents
chromic gut
when does chromic gut dissolve in vitro
pepsin and HCl: 96 hours
dog gastric content: 5 hours
human gastric content: 22 hours
trypsin: 9 days
dog jejunal content: 6 days
chromic gut dissolution in vivo
stomach: 2 days
duodenum: 1 day
jejunum: 3 days
colon: 7 days
when does dexon dissolve in vivo
stomach: 28 days
duodenum: 22 days
jejunum: 21 days
colon: 21 days
when does vicryl dissolve?
stomach: 28 days
duodenum: 22 days
jejunum: 22 days
colon: 21 days
what inverting suture patterns are used in GI surgery?
- cushing
- connell
- lembert
- modified gambee
- stapling
what appositional suture patterns are used in GI surgery?
- simple interrupted
- simple continuous
what everting suture patterns are used in GI surgery?
nONE
what is cushing suture good for?
inverting: does not penetrate the lumen
if it’s the first layer; have to know you’re getting the submucosa!
which one penetrates the lumen: connell or cushing?
connell
what is lembert good for?
bladder
in what species are modified gambees commonly used?
swine!
what is EEA?
end to end
the majority of bowel sutures are what pattern?
simple continuous
