Abomasal Displacement & Volvulus Flashcards
1
Q
Define LDA
A
left displaced abomasum
2
Q
Define RDA
A
right displaced abomasum
3
Q
Define RTA
A
right torsion of the abomasum (used interchangeable with right abomasal volvulus)
4
Q
define antro pexy
A
pexy of the antral portion of the abomasum
5
Q
define pyloro pexy
A
pexy of the pylorus (not commonly done due to risk of stricture formation)
6
Q
define abomasal pexy
A
pexy of the abomasum
7
Q
define omental pexy
A
pexy of the greater omentum
8
Q
LDAs are a _____ issue.
A
management
9
Q
most abomasal displacements are ____s.
A
LDAs
10
Q
DAs are most likely to occur… when? why?
A
at start of lactation, or 45 days after calving. because this is when peri parturient diseases take place
11
Q
what signalments of cows are more likely to get DAs ?
A
- holsteins, Ayrshires, guernseys
- large abdominal cavities
- age 4-7 (multiparous)
- start of lactation, after calving
12
Q
what the risk factors predisposing to DAs?
A
- spring szn
- rapid change in diet
- decreased exercise
- high concentrate diet
13
Q
what diseases increase risk of getting DAs? tell me one word for each as to why this predisposes to DAs
A
- hypocalcemia - motility
- ketosis - appetite
- retained placenta - appetite
- metritis - appetite
- mastitis - appetite/motility
- endotoxemia - appetite
14
Q
describe the pathophys of DAs
it is a multifactorial syndrome based on ____.
A
hypomotility
decreased appetite –> small rumen –> decreased motility –> abomasal atony –> microbial fermentation –> gas production –> displaced abomasum
15
Q
tell me the pathway of the abomasum during an LDA
A
abomasum fills up with gas and. becomes distended, then slips under the rumen to the left and goes to the left
creates a partial pyloric outflow obstruction
16
Q
tell me the pathway of the abomasum during a RDA
A
abomasum becomes gas distended, floats dorsally (it’s already on the R)
creates a partial pyloric outflow obstruction
17
Q
DAs create what metabolic derangement? why?
A
metabolic alkalosis w/ paradoxic aciduria
HCl produced in abomasum, because of pyloric outflow obstruction, HCl is trapped in abomasum, so you get metabolic alkalosis.
18
Q
tell me the pathway of the abomasum during an RTA
A
abomasum becomes gas distended, floats dorsally (it’s already on the right) – starts as a RDA
twists counterclockwise when viewed from behind
additional counterclockwise turn when viewed from above
19
Q
RTAs may include the ____.
A
omasum
20
Q
why are RTAs so much worse than RDAs?
A
RTAs create a complete pyloric outflow obstruction, while RDAs create a partial pyloric outflow obstruction
RTAs cause vascular compromise and potential tissue revitalization
21
Q
true or false: an animal with signs of colic is never alright until morning, and usually requires immediate surgical intervention.
A
TRUE!!!!!!!
22
Q
how do you diagnose an LDA/RDA/RTA? general
A
PE
- auscultation/percussion
- succussion
- rectal
can use BHBA test, stall side Ca test (v expensive), blood lactate
can technically do CBC/chem, but it would be ridiculous to (but values might show up on NAVLE)
23
Q
tell me about the HR when cow has LDA/RDA/RTA
A
potentially normal for RDA/LDA
tachycardia for RTA
24
Q
tell me about the rumination when cow has LDA/RDA/RTA
A
RDA: usually still present
LDA: usually still present. harder to hear b/c of rumen displacement by distended abomasum
RTA: absent
25
tell me about temp when cow has LDA/RDA/RTA
usually normal
26
tell me the C/S for LDA
**decreased appetite --> decreased rumen motility**
**decreased milk production**
hyperketonemia
feces normal or slightly softer
rectal temp = N
resp = N
**pulse = N**
**rumen contractions decreased (Hard to hear)**
27
tell me the C/S for RDA/RTA
edit: this is more for RTA!!
decrease appetite
feces absent or scant
**sunken eyes**
**HR=elevated**
weak pulse (poor venous return)
bilateral abdominal distention
**ruminal stasis & bloat**
colic
8th rib --> middle paralumbar fossa ping and succession
28
tell me about the bloodwork with an LDA
**alkalotic**
**increase bicarb**
**hypochloremia**
**hypokalemia**
hypoglycaemia
ketonemia
stress leukogram
29
tell me about the bloodwork with an RDA/RTA
hypovolemia
dehydration
hemoconcentration
hyperglycaemia
**metabolic alkalosis**
**hypochloremia**
**hypokalemia**
hypocalcemia
hyponatremia
**paradoxic aciduria**
30
what do you expect to hear upon auscultation and percussion with an LDA/RDA/RTA?
high pitched "hyper resonant" metallic *ping* (caused by gas)
31
where do you auscultate and percuss on PE?
above and below the line made from the tuber coxa to just above the olecranon
32
other than DAs, what conditions cause a "false ping"? how do you rule them out?
gas filled rumen on L, pneumorectum
do a rectal exam
33
why do we do a rectal exam last?
introduces air
34
what do you expect to feel on a rectal for an LDA/RDA/RTA?
you can feel the displaced abomasum if quite large
feces dry (decreased passage of ingesta)
35
How do you differentiate b/t RDA and RTA?
RTA will be an emergency, cow will be in shock (high HR, dehydration, hypovolemia, etc)
36
what are the ddx for an LDA? (left side ping and possible distension)
ruminal tympany
pneumoperitoneum
37
what are the ddx for an RDA (right side ping and possible distension)
cecal distention
gas in spiral colon
pneumorectum
pneumoperitoneum
physeometra
38
what is the general tx of choice for LDA, RDA, and RTA?
surgery
39
for DA sx, where do you make your incision? how big?
paralumbar fossa, at least one hand from transverse process, mid paralumbar fossa, ensure a few inches caudal to 13th rib at ventral end) antro-pexy benefits from a lower incision)
20cm incision (may enlarge if required)
40
when you make your incision for repairing an LDA or RDA, what layers are you cutting through? from outside to inside
skin + sq
external abdominal oblique
internal abdominal oblique
transverse abdominus + peritoneum
41
tell me how you're going to make your incision in the paralumbar fossa for a right-sided sx to fix an LDA or RDA. like when you go through each layer, what do you do?
1. skin + external abd. oblique: sharp dissection
2. internal abd. oblique + transverse abdominius: blunt dissection (preferred) or careful sharp dissection
3. transverse abdominus + peritoneum: blunt dissection
42
tell me the broad steps to fixing an LDA using the right flank approach
1. incision
2. quick exploratory
3. approach - find the abomasum
4. reduction - deflate and move abomasum
5. perform pexy
6. close
43
fixing LDA using right flank approach:
what are you doing during the quick exploratory part?
looking for adhesions
palpating liver and omasum
44
fixing LDA using right flank approach:
what are you doing during the approach part?
1. move to caudal abdomen with L hand
2. pass around omental sling and under L kidney
3. move up and around caudal dorsal rumen until you hit L body wall
4. move cranially until you feel distended viscous of the abomasum
45
fixing LDA using right flank approach:
what are you doing during the reduction part?
1. passive or active deflation - use large bore (10-12ga) needle attached to sterile tube or vacuum pump
*remember to guard needle on the way to abomasum and kink/guard upon removal*
2. L hand placed on top of abomasum, gently push it under rumen
alternatively, gently pull on greater momentum at 45 degree angle until you pull abomasum under rumen
46
why do you deflate the abomasum before moving it under the rumen?
reduces trauma upon reduction attempts
47
fixing LDA using right flank approach:
when is the reduction part done?
**when you can visualize the pyloric antrum at the incision site**
48
what are the pros to using the right flank approach to fixing an LDA?
- can be done standing
- can be done w/o assistance
- can do through abdominal explore
- useful for LDA, RDA, RTA, and other intestinal accidents
49
what are the cons to using the right flank approach to fixing an LDA?
- hard to navigate a late term pregnancy
- adhesions from abomasal ulceration and peritonitis are harder to visualize and navigate from the R side
50
tell me the broad steps to fixing an RDA using the right flank approach
1. incision
2. quick exploratory (?)
3. ID abomasum
4. ID if displaced or volvulus
5. reduction - deflate and move abomasum
6. pexy
7. close
*right flank approach is the only way to do it*
51
how do you ID the abomasum while fixing an RDA using the right flank approach?
ID the gas filled viscous immediately cranial to your incision against the R body wall
52
how do you know if the abomasum is in volvulus or just displaced when going from the right flank to fix an RDA/RTA?
move hand down medial side of distended abomasum
if you can run your hand down the medial aspect until you reach the abdominal floor, it's just displaced
53
tell me the broad steps to fixing an RTA using the right flank approach
1. incision
2. quick exploratory (?)
3. ID abomasum
4. ID if displaced or volvulus
5. reduction - deflate, untwist, move abomasum
6. pexy
7. close
*right flank approach is the only way to do it*
54
describe the reduction part of the sx to fix an RDA using the right flank approach?
1. passive/active deflation using large bore (10-12ga) needle attached to sterile tube or vacuum pump
*must guard needle on the way in and kink/guard on the way out*
2. L hand placed on top of abomasum and gently pushed down, correcting CCW twist
3. gently pull on greater momentum or pylorus at 45 degree angle until you pull the abomasum up to the incision site
55
fixing RDA using right flank approach:
when is the reduction part done?
**when you can visualize the pyloric antrum at the incision site**
56
describe the reduction part of the sx to fix an RTA using the right flank approach?
1. passive/active deflation using large bore (10-12ga) needle attached to sterile tube or vacuum pump
*must guard needle on the way in and kink/guard on the way out*
2. correct CCW twist as seen from above by **moving abomasum in CW direction**
3. correct CCW twist as seen from behind by **moving abomasum in CW direction**
4. gently pull on greater momentum or pylorus at 45 degree angle until you pull the abomasum up to the incision site
57
why is it especially important to deflate abomasum before fixing an RTA?
abomasum is often fluid filled and impossible to reduce without emptying
58
fixing RTA using right flank approach:
when is the reduction part done?
**when you can visualize the pyloric antrum at the incision site**
59
with an RTA, should you correct the electrolyte imbalances and fluid loss before or after sx?
before
60
before closing while fixing an RTA, should you check the tissue viability?
yes!
euth cow if tissue compromised
61
for LDA/RDA/RTA, the pexy part is the same. what are the 2 ways to do the pexy?
omentopexy
pyloro/antero-pexy
62
describe an omentopexy
1. 2 horizontal mattress sutures (3 chromic gut) are placed in the greater momentum approx. 1 inch from greater curvature of abomasum
2. sutures anchored through the transverse abdominus/peritoneum at the cranial ventral aspect
3. greater omentum is incorporated into the closure of the T. abdominus
63
why is the greater omentum incorporated into the closure of the transverse abdominus during an omentopexy?
- allows for close anatomic anchoring of abomasum
- no chance of causing iatrogenic pyloric obstruction or abomasal leakage (no suture placed in abomasum)
64
what is the risk when performing an omentopexy?
omentum can stretch/tear, resulting in recurrence of displacement
65
describe an pyloro/antro-pexy
1. horizontal mattress sutures placed in pyloric antrum, 3-5cm proximal to pylorus - *do not take full thickness bites* *only seromuscular bites*
2. sutures anchored through the transverse abdominus/peritoneum at the cranial ventral aspect
66
why should you not take full thickness bites while performing a pyloro/antro-pexy?
to reduce occurrence of fistula formation
67
when should you choose a pyloro/antropexy over an omentopexy?
in fat cattle (bc their omentums are more fragile or torn)
68
toggle suture surgery is only performed when there's an ____.
LDA
69
performing a toggle surgery when there's an RDA results in what?
may result in volvulus
70
when a cow is rolled on her back and slightly left, what happens to her abomasum?
back: abomasum floats to ventral abdomen
left: abomasum floats into a R paramedian position
71
give me the step by step to a toggle suture
1. cow cast on R side
2. 3-6 in caudal to xiphoid & 3-6 in R of midline = prepped
3. surgeon or assistant applies pressure to caudal abdomen
4. ID abomasum by percussion/auscultation
5. trocar placed over *ping* caudal to xiphoid and medial (R) of midline *avoiding large vessels*
6. trocar quickly and forcefully pushed through body wall and into abomasum
7. remove handle, reinsert stylet, keeping gas from escaping with a finger over trocar
8. confirm abomasal placement by smell or pH (should be acidic)
9. remove stylet, push 1st suture through w/ stylet, remove trocar, clamp 1st suture w/ hemostats so you don't lose it
10. place 2nd suture 2-3in cranial-medial to first
11. evacuate gas, THEN remove trocar
12. tie ends together using a button (or similar), 3-4 in of slack b/t button and abdominal wall
13. roll cow **completely over** CW from the rear
14. admin tx and allow to rise
72
why do you evacuate the gas before removing the trocar in a toggle suture procedure?
you don't want there to be a big tug on the suture from inflated abomasal and rip out the suture
73
what are the pros to using the toggle suture technique to fix an LDA?
- cheaper than sx
- quicker w/ less prep and clean up
- if successful (and case dependent), faster recovery and less peritonitis
- less muscle trauma
74
what are the cons to using the toggle suture technique to fix an LDA?
- blind technique
- sutures can rip out
- requires additional help
- reserved for "loser cases"
- adhesions prevent success
- cow is now down
75
what is the medical therapy option to fix an LDA?
rolling
but this results in 70% recurrence
76
what are the post-sx treatments?
IV fluids - Ca2+ SQ for hypocalcemia, hypertonic solution so they get up and drink
pump rumen - K, Na, etc. to help rumen function
antibiotics and **pain mitigation**
77
true or false. there is an association between LDA surgical procedure and longevity in the herd.
FALSE! THERE IS NO ASSOCIATION!
78
a cow with dystocia and low BHBA that has an LDA is (more/less/the same) likely to be culled within 60 days
more
79
true or false. blood calcium is NOT predictive of success of LDA sx
TRUE!!
80
a cow with an RDA/RTA with a HR >100 bpm had a 56% of what?
being salvaged, euthanized, or dying
81
how does blood lactate dictate RDA/RTA prognosis?
pre-sx lactate <2mmol/L = good outcome
pre-sx lactate >6mmol/L = poor outcome
82
which is the better prognostic indicator of RDA/RTA, HR or lactate?
lactate
83
how does chloride dictate RDA/RTA prognosis?
hyperchloremia = more likely to be culled within 30 days
84
what are the possible complications of fixing displaced abomasums?
- dehiscence and SSI
- omentopexy failure and re-displacement
- peritonitis
- fistulation (full thickness antropexy)
- pyloric stricture w/ pyloropexy
- hemorrhage - trocar misplacement
