Principles of Gastrointestinal Surgery Flashcards
(30 cards)
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
