Small Intestine Flashcards
Predisposing conditions of the small intestine for young horses
Incarcerations of the mesodiverticular bands
Volvulus
Predisposing conditions of the small intestine for old horses
SI incarceration in the epiploic foramen
Strangulation by a pendunculated lipoma
CS of SI obstructive dz
Non-specific signs
Gastric reflux during nasogastric intubation
Moderate to severe abdominal pain
Distended SI on rectal exam
Inguinal hernia: swollen scrotum
Single factor that horses should be considered for sx?
All horses having distended SI (few can be treated successfully)
Decisions when they should get SI surgery
Persistent abdominal pain
HR > 80 bpm
Abnormal rectal exam
Gastric reflux
Peritoneal fluid alterations
T/F: if there are problems with the SI and the horse has a fever you SHOULD operate
FALSE- never
Prerequisites for resection of the SI
Isolate affected intestine from incision
ID viable mesentery and intestine
Correction of intestinal displacement
Decompressed the proximal intestine
How is viability of the SI determined?
Grossly: color, contractions during handling , bowel wall thickness
Iv injections of fluorescein with UV light (vasc. integrity)
Doppler assessment of blood flow
How is distention of the SI measured?
Water manometer: 15 cm water or more indicate a small prognosis (susceptible to ileus, ↑ secretion, adhesions)
Hand suture of the SI
Apposition of the intestinal layers
Slight inversion
2-0 absorbable suture
Continuous suture with interruption
Surgical stapling (GIA)
GI anastomosis is used to create a blind stump at the prox. and dist. end of the intestine
Poor with thickened tissues
Surgical stapling (TA-90)
Thoraco-abdominal stapling
Better with thickened tissues
SI volvulus
Most frequently reported dz of SI
Young horses, linked to verminous arteritis
CS associated with SI volvulus
Acute severe pain with dehydration
Distention of the SI
Reflux fluid into the stomach
Shock and bowel degeneration
SI volvulus tx
SX correction: exteriorization of the entire SI and rotation of the intestine and mesentery around the abdominal incision
SI volvulus prognosis
> 50% of intestine involved: euthanasia
<50% alive in 1 year
Guarded to poor
Mesenteric incarcerations
When the SI is subject to incarceration in mesenteric rents of its own mesentery
Lesions: lipomas, mesodiverticular bands and meckel’s diverticulum
Rents of the SI
Found in dist. jejunum as remnants of the mesodiverticular band
Seen in mesoduodenum of pregnant mares
TX of mesenteric incarcerations
Resection and anastomosis
If the ileum is involved: ileocolostomy
Inguinal hernia
Passage of the abdominal contents from the abdominal cavity into the inguinal canal
Most common in adult stallions, congenital in foals
Inguinal hernia contents
Omentum of SI most common
Also see colon, bladder, pelvic flexure of large colon
Indirect hernias
Most common in horses
Goes into the vaginal tunic and shares the same space as testicle
Occurs with hernial sac ruptures
Direct inguinal hernias
Goes through a peritoneal defect outside the vaginal tunic
Traumatic incident with peritoneal rupture
Which breeds are prone to inguinal hernias
Standardbreds, TN walking horses, American saddlebreds, and warmbloods
Enlarged inguinal rings (descention of testicle post breeding)
Which part of the SI is mostly involved in inguinal hernias?
Ileum: trapped by the inguinal ring dist. to the peritoneal reflection
CS associated with inguinal hernias
SI obstruction
Progressive periodic abdominal pain
Swollen testicle
Dx of inguinal hernias
Rectal exam
Testicular palpation
US
Sx approaches for inguinal hernias
Inguinal approach: testicle and SI, reducing hernia and testicular amputation
Ventral midline: evaluation and resection of SI
What happens if the surgeon tries to save the testical for inguinal hernias?
↑ risk of second hernia or cause lymphatic and venous stasis with testicular fibrosis
Prognosis of an inguinal hernia
25-75% survival
Good to guarded
Prone to ileus and SI adhesions
Inguinal hernias in the foal
Observed @ birth or few days of life
Unilateral or bilateral
Incurred during straining to pass meconium
CS of inguinal hernias in foals
Swollen scrotum, edema of prepuce, fluid sounds in scrotum, non painful, hernia recurs after reduction
Conservative tx in foals with inguinal hernias
Daily manual reduction
Support strap
Resolve by 3d-3m, good prognosis
Surgical tx for inguinal hernias in the foal
For large, non-reducible hernias
No resolved by 4m
Bilateral castration, fair to good prog
Entrapment in the epiploic foramen
SI incarcerated in the epiploic foramen: older horses
An enlargement of the foramen due to ↓ size of cd. lobe of the liver
Dx of entrapment in the epiploic foramen
SI entrapped on the dorsal right side of the abdomen
Danger with enlargement of foramen: portal vein, cd. vena cava, resection and anastomosis
Prognosis of Entrapment in the epiploic foramen
Guarded to poor
CS associated with shock, difficulty in reduction and adhesions
Ileal impaction
Most common non-strangling obstruction
SE US
Bermudagrass hay associated
Early dx of ileal impaction
Marked abdominal pain related to SI spasm
Rectal exam dx
Later dx for ileal impaction
↓ abdominal pain
Marked SI distention on rectal
Moderate to severe SI reflux
↑ protein on abdominocentesis
Medical tx for ileal impaction
If non-progressive abdominal pain, rectal confirmed impaction and norm abdominocentesis
IV fluids, nasogastric decompression, analgesics
Responds in 24-36 hrs
When is sx tx for ileal impaction needed?
If progressive abdominal pain, open rectal dx or abnormal abdominocentesis
Sx tx for ileal impaction
Milk impaction into cecum: inject saline/ carboxymethylcellulose into lumen, lido for spasms
Ileal bypass or enteromy last resort
Post op care and prognosis for ileal impaction
Ileus heals in up to 7d and gradual return to diet over 3d
Fair to good prog, depends on ease of reduction
What causes SI adhesions?
Mesenteric abscesses or previous sx
Tx of SI adhesions
Resection and anastomosis
Bypass: GIA, 9.3 cm stroma and suture mesenteric rent
