Abdominal Sx 3 Flashcards
anatomy of large intestine: what is the diverticulum off colon called? does it communicate with ileum?
cecum
no
anatomy of large intestine: which has a long mesocolon, the small intestine or the large intestine?
small intestine has long mesentery and large intestine has a short mesentery
large intestinal bacteria? what Gram and aerobe status are most common
GRAM NEGATIVE ANAEROBES
does large intestine have good collateral circulation
NO, unlike the small intestine it has poor collateral circulation
so, wound tensile strength is slow and bowel viability is hard to assess
you are suspicious of a mass on the colon. should you perform a full thickness biopsy?
NO it is too high risk to do this on colon. you only ever remove areas of suspected avascularity or necrosis
how is cecal disease (cecal impactions, inversion, neoplasias) treated
typhlectomy (excision) (it is not called a cecumectomy, that would make too much sense)
typhlotomy not recommended
what is most common type of neoplasia in cecum
GIST, gastrointestinal stromal tumor
what is Hirschsprung’s disease? is it common in SA?
congenital megacolon.
absence of mesenteric ganglionic cells in distal colonic segment that cause permanent muscular spasm of affected area, so functional obstruction of bowel
this is rare in SA
what is wrong? how to treat?
full of poop (obstipated)
medical management first unless obvious neoplastic cause
manually deobstipate under SEDATION OR GA
if you need to refer, do so to an IM specialist
anatomy: what provides blood supply for the large intestine?
cranial and caudal mesenteric artery/vein
subtotal colectomy: what is the important blood supply to preserve?
CRANIAL RECTAL BRANCH of caudal mesenteric artery
do cats adapt well to subtotal colectomy
yes, they adapt well to loss of water absorptive capability; 80% will eventually not have diarrhea and good function
what are 2 examples of benign large intestinal neoplasia? what layer of LI do they invade?
adenomatous polyps and leiomyoma
they are in the mucosa and do not invade submucosa
what are 2 examples of malignant large intestinal tumors?
adenocarcinoma and leiomyosarcoma
carcinoma in situ - is malignant cells but don’t invade basal lamina, so only in mucosa
who most commonly gets chronic volvulus
large breed dogs, especially German shepherds
risk factors include previous GI disease, previous abdominal sx, EPI
what is carcinoma in situ
malignant cells present in mucosa but no invasion through basal lamina (group of abnormal cells that are only found in the place they first formed)
what is wrong with the large intestine?
colonic volvulus
note severe gaseous dilation and malpositioning of the large intestine
what is wrong with the large intestine?
nothing, this is a normal canine large intestine
describe surgical treatment of colonic volvulus
- CRITICAL surgical emergency!
- derotate colon. there is very high reperfuision risk if black/ischemic
- R&A may be needed if devitalized
- ALWAYS do a left-sided colopexy
- DO NOT cut down to muscular layer of diseased colon; SCARIFY ONLY
- 24 pot-op care
name 2 possible causes of colonic perforation
sharp or blunt abdominal trauma, eg. GSW, knife wound, dog bites, bone fragments, rarely FBs
iatrogenic
non-traumatic perforation due to steroid admin or torsion
what surgical procedure should you perform for treatment of splenic neoplasia
complete splenectomy (partial not recommended)
what type of biopsy us most often used for splenic biopsy
aspiration/Trucut
but biopsy in general is uncommon, usually just remove entire spleen
splenic mass: unless metastatic diseases present, it is difficult to differentiate between being and malignant masses without _______
HISTOPATHOLOGY
what is the most common splenic mass in a DOG
hemangiosarcoma (1/3 to 2/3 all splenic masses are malignant, and 2/3 of these are HSA)