1. Bovine Abomasal Surgery
By Eoin Ryan MVB

2. Introduction Abomasal Surgery Post-op Medical Management LDA RDA
RTA/RVA
Post-op Medical Management

3. Surgical Approaches to the Bovine Abdomen
Left flank: caesarean sections, access to rumen, LDA
Right flank: thorough exploration of the abdomen possible (SI & LI), LDA, RDA &RDA and torsion
Right paramedian: caesarean sections to remove emphysematous calves, LDA & RDA
Midline: rarely used
Flank approach far and away the most common, incise through all layers, grid incision or modified grid
Method of closure varies (external rectus sheath apposition critical in the paramedian approach)

6. Flank Anaesthesia Line block Inverted “L”
Paravertebral: blocks T13, L1 & L2 cranial to L1, L2 & L3
Care: Do not overdo the volume, preparations with adrenaline may cause ischemia

10. Abomasal Surgery LDA – Left Displaced Abomasum
RDA – Right Displaced Abomasum
RVA – Right Volvulus of the Abomasum

11. Risk Factors for Abomasal Problems
High concentrate diet
Insufficient crude fibre & roughage
Hypocalcaemia – clinical or subclinical
Stress / Concurrent disease (50 – 60% cows) eg ketosis, fatty liver, metritis, RFM
Twins / large calf
More common in both young and old cows
Higher yielders
Most common in the first 6 weeks post-calving
May occur up to 6 weeks before calving

12. Diagnosis History & Signalment Clinical Exam
Dairy cow recently calved, back in the milk and not eating concentrates (selective inappetance – ketosis)
Clinical Exam
Abdominal percussion
Rumeno-reticular motility
Rectal examination
Heart rate (very important in differentiating dilation from volvulus)
Skin tent / sunken eyes

13. Abnormal “Pings” Left flank dorsally, under last ribs:
DDx: LDA 99% of the time
Much less likely: rumen gas cap; pneumoperitoneum, abscess on Left body wall
Right flank craniodorsally under rib cage:
RDA/RVA (RVA “pings” can extend cranially as far as the 9th intercostal space)
Caecal torsion/volvulus
Right paralumbar fossa:
Caecal dilation/volvulus
Right sided abomasal volvulus

14. Thorough Percussion: Detection of pings

15. Left Displaced Abomasum

16. Right Displaced Abomasum: two common sites

18. Diagnostic Tests Haematology - not a lot to be seen usually
Serum biochemistry
hypochloraemia (proximal GI obstruction)
hypokalaemia (proximal GI obstruction)
metabolic alkalosis (proximal GI obstruction)
ketosis - -hydroxybutyrate (LDA / RDA)
hypocalaemia (abomasal /caecal displacement)
Liptac test
Using auscultation and percussion, identify the area of “pings”
“Pings” = gas; below this should be abomasal fluid
Insert a 9cm 18G spinal needle 2 inches below the bottom of the “pings” and aspirate fluid
If pH < 5 = abomasal fluid

24. Prognosis for Return to Function
Medical therapy alone – only 5-15%
Closed surgical procedures – 77-91%
Conventional open surgeries – %

25. Intervention V Culling
Cost-benefit analysis (Abonyi, 1988)
“with the policy of early surgical intervention the surplus value of additional meat and milk production and breeding performance, discounting the value of meat had the animals been immediately destroyed or culled, out weighed the total costs of intervention by a factor of 5.76”

26. Abomasal Repositioning and Stabilisation
Closed techniques:
rolling (high % of recurrence)
percutaneous toggling
Open techniques:
Right flank omentopexy
Left flank abomasopexy
Right paramedian abomasopexy

27. CONSERVATIVE TREATMENT
Rolling
Cast to right lateral recumbency
Then dorsal recumbency, rock gently & ping
Sharp rotation onto left side ; then onto sternal recumbency and allow to stand
High % recurrence
Occasionally can result in RDA or RVA
NB – LDA only ; Rolling is contraindicated with RDA due to risk of inducing RVA

28. Transportation Helps expel gas from abomasum
Transient reduction or loss of “ping”
Often returns rapidly (within 6 to 8 hours)
Does not necessarily restore normal position or function
If risk factors for initial displacement still there - i.e. metritis; ketosis; hypocalcaemia; high concentrate diet – high likelihood of recurrance

29. Surgical Treatments for LDA
Right Flank
Omentopexy
Pyloropexy
Left flank
Abomasopexy
Right Paramedian abomasopexy
Toggle pin fixation

30. PRE-OP MED MANAGEMENT Electrolyte imbalances :
Abomasal conditions – hypochloraemic, hypokalaemic, metabolic alkalosis
Fluid therapy :
LDA/RDA – usually do not require fluids pre-op
RVA – severe dehydration/shock
Hypertonic saline 7.2% (216g in 3L pumped in over mins)
Follow with isotonic10L 0.9% NaCl iv (90g salt in 10L water) at rate of 4-6L/hr
Add KCl at 0.2% = 20g/10L ; NB No HCO3¯

31. PRE-OP MED MANAGEMENT 400ml 40% Ca borogluconate s/c NSAIDs
Antimicrobials

33. Right Flank Omentopexy
NB. Position for incision site critical
Bottom of incision should be as close as possible to normal position of pylorus
Bottom of incision should be level with point where the ribs stop coursing caudally and begin to turn cranially
The incision should be no more then 2 inches caudal to the last rib
The length of incision is 6-8 inches (arm width)
Most common cause of surgical failure folowing omentopexy = tension due to incision placed too high and caudal

35. Right Flank Omentopexy
Ventral deviation of duodenum and mesoduodenum
Direct palpation of viscus to left of rumen
Gas decompression using 14G needle and 40 cm tubing (water bowl)
Push deflated abomasum under the rumen and apply gentle traction to the omentum
Identify omentum close to pylorus, “sow’s ear” not a consistent finding and may be too friable anyway
Incorporate 8-10cm length of omentum into the peritoneal/transversus first layer of abdominal wall closure

42. 4 Cardinal Points to the Omentopexy
(1) Proper Placement of Incision Site
The incision should not be too high or too far caudal (bottom of incision level with point where ribs stop coursing caudally and start to turn cranially) – otherwise tension may cause omentum to tear leading to failure
If the incision is made too far ventrally the intestines will prolapse making surgery and closure in particular difficult

45. 4 Cardinal Points to the Omentopexy
(2) Require a thick strong piece of omentum close to the pylorus
Classically the sow’s ear is used if strong enough (located 2-3 inches from pylorus and triangular in shape – frequently too small or not present)
Omentum should be within 4 inches of the pylorus and strong enough to hold 2 mattress stay sutures
If >4 inches from pylorus – risk of torsion around pexy

48. 4 Cardinal Points to the Omentopexy
(3) Surgical pexy must be performed that will last a minimum of 3 weeks so that a good adhesion will form
Suture material must be strong (6-8 metric catgut or polyglyclic acid – Safil/Vicryl)
The peritoneum must be included
If omentum is friable (chronic DA in a cow in very low BCS) then a pyloropexy may also be performed (stitches placed partial thickness through pylorus as well as omentum)

49. 4 Cardinal Points to the Omentopexy
(4) Spread the weight-bearing load when suturing
2 horizontal mattress sutures are placed at the bottom of the incision to take the main weight of the pylorus and abomasum (should be little pull on pexy if incision is low enough)
Sutures pass through internal AO, transversus Ab, peritoneum, omentum and back through the same layers
Sutures in cranial edge of the incision only

50. 4 Cardinal Points to the Omentopexy
(4) Spread the weight-bearing load when suturing
A bite of omentum is taken as part of the simple continuous closure until half way up the closure when starting from the bottom – this spreads the weightbearing load giving the pexy greater holding power

58. Left Flank Abomasopexy
Advantage of identification of ulcers or adhesions
Disadvantage – requires 2 operators for proper suture placement
Continuous suture with long ends placed in abomasum (not into lumen) 5-7 cms from junction with the omentum
2nd operator tells principal surgeon where to place external sutures
Cranial piece through first 6” caudal to xiphoid and 2” to right of midline, 2nd needle placed 4” caudally
Care not to incarcerate anything
Suture left in for 4-6 weeks

63. Right Paramedian Abomasopexy
The cow is sedated and rolled into dorsal recumbency
The abomasum (unless adhesed) will float to the midline
Tends to evacuate itself
Incision Site: halfway between midline and milk vein, 2” cranial to the umbilicus and running forward 8”
Incorporate omentum in the 1st layer of abdominal closure (internal rectus sheath and peritoneum)
Vital to appose the external rectus sheath well

64. Disadvantages of Right Paramedian Abomasopexy
Need help for casting and restraint
Dangers of hypoxaemia and aspiration of ruminal reflux
Large blood vessels – increased haemorrhage
Risk of abomasal fistulation and/or peritonitis

69. Abomasal Fistulae Umbilical hernia or infection Perforating ulcers
Complication of abomasopexy
Treatment: surgical correction

71. Toggle Pin Fixation
Closed
Laparoscopic

72. Closed Toggle-Pin Fixation
The cow is cast (+/- sedation) into dorsal recumbency
The abomasum should rise allowing the surgeon to detect “pings” on the ventral abdomen
The cow is rocked until the abomasum is returned to the right of midline
The trochar is introduced into the area of “pings” 4 inches from midline and 4 inches caudal to the sternum

73. Closed Toggle-Pin Fixation
The first toggle is then inserted quickly so that all the gas does not escape
The second toggle is placed 3 inches caudally to the first and the two ends tied
The suture should be left in place for 4 to 6 weeks
Disadvantages: blind surgery so there can be incarceration of bowel; incorrect realignment of abomasum; fistula formation

80. Laparoscopic Toggle-Pin Fixation
Advantages: can see where toggles are placed and ensure correct alignment and placement of the abomasum
Disadvantages: initial capital expenditure (€5,000 approx.) to purchase equipment
Still requires casting of the cow and the help needed for this

81. Omentopexy V Toggle-Pin
Cost-benefit analysis (Bartlett, 1995)
Costs considered : cost of treatment ; milk loss ; livestock loss (replacement cost & slaughter value based on % treated animals lost to herd within 120 days)
Cost by Toggle-pin was 65% of cost by omentopexy
Milk loss – 10% more for Toggle-pin

82. Omentopexy V Toggle-Pin
Best access to entire abdomen with right open surgery
Toggle-pin contra-indicated with RDA and RVA
Toggle-pin : risks of entrapment of bowel + penetration of another viscus + improper relocation + fistulation
Right Flank Omentopexy Preferable in valuable animal

83. Right Displacement of the Abomasum (RDA)
Right Dilation of the Abomasum
RVA/RTA
Right Volvulus/Torsion of the Abomasum

84. Right Displaced Abomasum
Diagnosis:
Dilation: similar to LDA history in dilation cases, “pings” under last 2 ribs on right flank, can’t palpate it on rectal examination, no signs of severe systemic changes
Treatment:
Right flank omentopexy
Incision as for LDA
Deflate with 14G needle – abomasum drops down below incision site
Locate pylorus; duodenum should be visible also
Perform omentopexy as for LDA

87. Right Torsion/Volvulus of the Abomasum
Depending on longevity of condition, cows show varying degrees of systemic involvement – sunken eyes, skin tent, distended abdomen, fluid on ballottement, large area of “pings” on right flank, occasionally palpable per rectum in advanced cases (poor prognosis)
Severe hypokalaemia

89. Right Torsion/Volvulus of the Abomasum
Main surgical difference between RVA and RDA = RDA is gas-filled whereas RVA is mainly fluid-filled especially in advanced cases
Right flank laparotomy
Deflation with 14G needle
Usually must release fluid to untorse
A purse-string suture is placed in the abomasal wall (partial thickness)

92. Right Torsion/Volvulus of the Abomasum
An assistant places a double-throw and holds the two ends ready to tighten the purse-string when necessary
The surgeon makes a shallow incision in the centre of the purse-string through the serosa, muscularis but not the mucosa
A large stomach tube is pushed through the mucosa and the purse-string tightened simultaneously to prevent leakage

95. Right Torsion/Volvulus of the Abomasum
The fluid is siphoned off and its volume is measured to determine prognosis (>25 litres gives a bad prognosis due to overstretching of abomasal muscle and possible vagal nerve damage leading to ileus post-op)
The incision is over-sowed and cleaned

98. Right Torsion/Volvulus of the Abomasum
The torsion/volvulus is invariably anti- clockwise and from lateral to medial
The surgeon must place their arm ventrally and toss the abomasum in a clockwise direction and from medial to lateral
If untwisted correctly the pylorus can be drawn up to the incision without excessive tension and the duodenum seen coursing caudally

103. Right Torsion/Volvulus of the Abomasum
Omentopexy is performed as before
Post-op medical management is extremely important
Intravenous fluids (hypertonic/isotonic)
Oral fluids - stomach tube 20L water containing
200 to 250g coffee (caffeine stimulates abomasal motility and emptying)
100g KCl (1 tub of Lo Salt)
propylene glycol
“Stimulex” powders

104. Post-Op Medical Management
Routine Post-op Treatment for LDA / RDA
400ml 40% Ca borogluconate s/c
off concentrates for 48 hours
antibiotics for 5 days
NSAIDs
In severe cases a lidocaine drip is recommended to combat ileus -

107. Post-Op Medical Considerations
RVA – as well as the hypochloraemia and metabolic alkalosis, there is a much more severe hypokalaemia which leads to muscle weakness, dullness and reduced smooth muscle contractility
Potassium cannot be supplemented iv at > 0.2% solution
Therefore, the best way to raise a severely low blood potassium is via oral supplementation

108. POST-OP MED MANAGEMENT
10 – 20L of isotonic saline with 0.2% KCl iv over 2-3 hours is ideal (2g KCl/L)
K+ can be given PO at a dose of 0.5-1g/kg
Can give 0.5g/kg KCl up to a maximum of 1g/kg KCl in a 24 hour period
For RVA give 150 to 300g KCl depending on severity and amount of fluid drained from abomasum

109. Post-Op Ileus
Ileus = abnormal lack of motility of the gastrointestinal tract
Post-op ileus occurs after almost every surgery, especially surgeries involving the GIT
It is a major problem post-RVA
Combat ileus : caffeine ; Ca borogluconate ; laxatives ; probiotics
Treatment of choice for severe paralytic ileus = Intravenous Lidocaine Therapy
lidocaine dose = 50ml/litre at slow to medium flow rate - usually give a total of 10L daily (500ml lidocaine in 10 litres saline)

110. Prognosis with RVA ↓ with heart rate >100 bpm
↓ with severity of systemic signs pre-op
NB : very poor if > 20L fluid in abomasum
↓ with concurrent abomasal ulcer
Must pick up and perform surgery in first 12 hrs for reasonable prognosis

111. Abomasal Surgery - Conclusions
Early surgical intervention is warranted in >90% of cases of abomasal displacement
It is important to be confident and skilled in performing surgical procedures
Pre and post-op medical management is vital in returning cows to productivity as quick as possible

112. Pedigree Jersey V Holstein
Jersey cows are much more delicate
Jersey cows are more prone to hypocalcaemia (clinical and subclinical)
Jersey cows are equally as susceptible to developing LDA’s, RDA’s, RVA’s and caecal dilation/torsion
In my experience it is best to operate ASAP rather than treat medically
If left they very quickly become weak and recumbent making surgery difficult/impossible

113. Acknowledgements John Berkery and Donal Lynch and the XL VETS team
The sponsors Intervet-Schering Plough Animal Health for facilitating the talk
Thank you for listening