Small Intestine

Question 1

Predisposing conditions of the small intestine for young horses

Answer 1

Incarcerations of the mesodiverticular bands
Volvulus

Question 2

Predisposing conditions of the small intestine for old horses

Answer 2

SI incarceration in the epiploic foramen
Strangulation by a pendunculated lipoma

Question 3

CS of SI obstructive dz

Answer 3

Non-specific signs
Gastric reflux during nasogastric intubation
Moderate to severe abdominal pain
Distended SI on rectal exam
Inguinal hernia: swollen scrotum

Question 4

Single factor that horses should be considered for sx?

Answer 4

All horses having distended SI (few can be treated successfully)

Question 5

Decisions when they should get SI surgery

Answer 5

Persistent abdominal pain
HR > 80 bpm
Abnormal rectal exam
Gastric reflux
Peritoneal fluid alterations

Question 6

T/F: if there are problems with the SI and the horse has a fever you SHOULD operate

Answer 6

FALSE- never

Question 7

Prerequisites for resection of the SI

Answer 7

Isolate affected intestine from incision
ID viable mesentery and intestine
Correction of intestinal displacement
Decompressed the proximal intestine

Question 8

How is viability of the SI determined?

Answer 8

Grossly: color, contractions during handling , bowel wall thickness
Iv injections of fluorescein with UV light (vasc. integrity)
Doppler assessment of blood flow

Question 9

How is distention of the SI measured?

Answer 9

Water manometer: 15 cm water or more indicate a small prognosis (susceptible to ileus, ↑ secretion, adhesions)

Question 10

Hand suture of the SI

Answer 10

Apposition of the intestinal layers
Slight inversion
2-0 absorbable suture
Continuous suture with interruption

Question 11

Surgical stapling (GIA)

Answer 11

GI anastomosis is used to create a blind stump at the prox. and dist. end of the intestine
Poor with thickened tissues

Question 12

Surgical stapling (TA-90)

Answer 12

Thoraco-abdominal stapling
Better with thickened tissues

Question 13

SI volvulus

Answer 13

Most frequently reported dz of SI
Young horses, linked to verminous arteritis

Question 14

CS associated with SI volvulus

Answer 14

Acute severe pain with dehydration
Distention of the SI
Reflux fluid into the stomach
Shock and bowel degeneration

Question 15

SI volvulus tx

Answer 15

SX correction: exteriorization of the entire SI and rotation of the intestine and mesentery around the abdominal incision

Question 16

SI volvulus prognosis

Answer 16

> 50% of intestine involved: euthanasia
<50% alive in 1 year
Guarded to poor

Question 17

Mesenteric incarcerations

Answer 17

When the SI is subject to incarceration in mesenteric rents of its own mesentery
Lesions: lipomas, mesodiverticular bands and meckel’s diverticulum

Question 18

Rents of the SI

Answer 18

Found in dist. jejunum as remnants of the mesodiverticular band
Seen in mesoduodenum of pregnant mares

Question 19

TX of mesenteric incarcerations

Answer 19

Resection and anastomosis
If the ileum is involved: ileocolostomy

Question 20

Inguinal hernia

Answer 20

Passage of the abdominal contents from the abdominal cavity into the inguinal canal
Most common in adult stallions, congenital in foals

Question 21

Inguinal hernia contents

Answer 21

Omentum of SI most common
Also see colon, bladder, pelvic flexure of large colon

Question 22

Indirect hernias

Answer 22

Most common in horses
Goes into the vaginal tunic and shares the same space as testicle
Occurs with hernial sac ruptures

Question 23

Direct inguinal hernias

Answer 23

Goes through a peritoneal defect outside the vaginal tunic
Traumatic incident with peritoneal rupture

Question 24

Which breeds are prone to inguinal hernias

Answer 24

Standardbreds, TN walking horses, American saddlebreds, and warmbloods
Enlarged inguinal rings (descention of testicle post breeding)

Question 25

Which part of the SI is mostly involved in inguinal hernias?

Answer 25

Ileum: trapped by the inguinal ring dist. to the peritoneal reflection

Question 26

CS associated with inguinal hernias

Answer 26

SI obstruction Progressive periodic abdominal pain Swollen testicle

Question 27

Dx of inguinal hernias

Answer 27

Rectal exam Testicular palpation US

Question 28

Sx approaches for inguinal hernias

Answer 28

Inguinal approach: testicle and SI, reducing hernia and testicular amputation Ventral midline: evaluation and resection of SI

Question 29

What happens if the surgeon tries to save the testical for inguinal hernias?

Answer 29

↑ risk of second hernia or cause lymphatic and venous stasis with testicular fibrosis

Question 30

Prognosis of an inguinal hernia

Answer 30

25-75% survival Good to guarded Prone to ileus and SI adhesions

Question 31

Inguinal hernias in the foal

Answer 31

Observed @ birth or few days of life Unilateral or bilateral Incurred during straining to pass meconium

Question 32

CS of inguinal hernias in foals

Answer 32

Swollen scrotum, edema of prepuce, fluid sounds in scrotum, non painful, hernia recurs after reduction

Question 33

Conservative tx in foals with inguinal hernias

Answer 33

Daily manual reduction Support strap Resolve by 3d-3m, good prognosis

Question 34

Surgical tx for inguinal hernias in the foal

Answer 34

For large, non-reducible hernias No resolved by 4m Bilateral castration, fair to good prog

Question 35

Entrapment in the epiploic foramen

Answer 35

SI incarcerated in the epiploic foramen: older horses An enlargement of the foramen due to ↓ size of cd. lobe of the liver

Question 36

Dx of entrapment in the epiploic foramen

Answer 36

SI entrapped on the dorsal right side of the abdomen Danger with enlargement of foramen: portal vein, cd. vena cava, resection and anastomosis

Question 37

Prognosis of Entrapment in the epiploic foramen

Answer 37

Guarded to poor CS associated with shock, difficulty in reduction and adhesions

Question 38

Ileal impaction

Answer 38

Most common non-strangling obstruction SE US Bermudagrass hay associated

Question 39

Early dx of ileal impaction

Answer 39

Marked abdominal pain related to SI spasm Rectal exam dx

Question 40

Later dx for ileal impaction

Answer 40

↓ abdominal pain Marked SI distention on rectal Moderate to severe SI reflux ↑ protein on abdominocentesis

Question 41

Medical tx for ileal impaction

Answer 41

If non-progressive abdominal pain, rectal confirmed impaction and norm abdominocentesis IV fluids, nasogastric decompression, analgesics Responds in 24-36 hrs

Question 42

When is sx tx for ileal impaction needed?

Answer 42

If progressive abdominal pain, open rectal dx or abnormal abdominocentesis

Question 43

Sx tx for ileal impaction

Answer 43

Milk impaction into cecum: inject saline/ carboxymethylcellulose into lumen, lido for spasms Ileal bypass or enteromy last resort

Question 44

Post op care and prognosis for ileal impaction

Answer 44

Ileus heals in up to 7d and gradual return to diet over 3d Fair to good prog, depends on ease of reduction

Question 45

What causes SI adhesions?

Answer 45

Mesenteric abscesses or previous sx

Question 46

Tx of SI adhesions

Answer 46

Resection and anastomosis Bypass: GIA, 9.3 cm stroma and suture mesenteric rent