Bovine GI Surgery & Dx Flashcards
Broad tx options for LDA
Medical (rather pointless but usefull for pre-op stableisation in some)
Closed Surgical
Open Surgial
Closed Sx tx options for LDA
Rolling
Blind tack
Toggle pin
Adv: Minimally invasive, minimal withold times etc, overall good px
Disadv: Higher complication rate - can be fatal (eg pexy of wrong organ, pull out etc)
Open surgical tx options for LDA (4)
1) Right flank omentopexy (*most versatile)
2) Right flank pyloropexy +/- omentopexy
3) Right ventral paramedial abomasopexy (so-called as can actually pexy the body of the abomasum rather than pylorus or omentum)
4) Left flank abomasopexy - requires assistant to retreive the sutures that are placed through the ventral right paramedian body wall having stiched a line in the seromuscular abomasum - have to reach across and pass through body wall
5) Right flank abomasopexy - similar to left - sutures penetrate ventral body wall once seromuscular suture line placed.
Laparoscopic assisted toggle pinning procedures for LDA (4)
1) 2-step approach: standing left flank followed by recumbent right paramedian
2) 1 step standing - left flank - uses a Speiker to penetrate right ventral body wall
3) 1-step recumbent - right paramedian
4) Ventral
Types of abomasal ulceration
- Nonperforating ulcers - mucosa/submucosa and don’t penetrate the BM (vague CSs, assoc. w concurrent dz)
- ‘Bleeding ulcers’ - nonperforating but occur in an area of significant vasculature rx in severe blood loss
- Perforating - with localised peritonitis (peritoneal cavity or omental bursa depending on location of the rupture)
- Perforating w diffuse peritonitis - grave px
General approaches to the bovine abdomen (7)
1) Left flank
2) Right flank
3) Ventral midline
4) Ventral (right) paramedian
5) (right) paracostal
6) Ventrolateral
7) Oblique (left)
Generally - left flank, left oblique, vental midline & left ventrolateral are used for C-section
Right flank, right paracostal & right paramedian used for access to abomasum for pexy (or poss reticulum).
Left flank/PLF approach; incision site & layers incised
Mid PLF is midway between TC and last rib, 6-8cm ventral to transverse processes. Can go more caudal for caesar
Incise skin, SQ, EAO, IAO, transversus, peritoneum
Uses of left flank PLF
Caesarean
Access to the rumen - rumenotomy, fistula
LDA (can approach from the left - need to reach over to pexy to right paramedian site
Uses of right flank laparotomy
LDA - the principal indication; can do omentopexy or pyloropexy +/- omentopexy (NB abomasopexy performed via right paramedian)
Access to much of the small and large intestine/caecum
Incision location and layers incised for (right) paramedian approach
4-6cm right of midline, 15-20 cm length from approx 8cm caudal to the xyphoid caudally. Parallel to midline. Incision will be lateral of midline but medial to the milk vein
Insision will be more caudal and left of midline for caesarean - runs from 5cm cranial to the umbilicus caudally
Incise skin, SQ, external rectus sheath, rectus abdominis, internal rectus sheath, peritoneum
Uses of (right) paramedian laparotomy
Principle is DA (left or right) - abomasopexy
TRP
Caesareans (left)
Location and layers incised with ventrolateral approach
Incision is lateral to the SQ abdominal/milk vein, curves dorsally as it comes caudally, remaining lateral to the attachment of the udder
Same layers incised as for the paramedian - skin, SQ, ext rectus sheath, rectus abdominis, internal rectus sheath and peritoneum
Uses of the ventrolateral approach
Usually left sided as an alternative approach for caesar - emphysematous foetus especially
Location and layers incised with ventral midline approach
Skin, SQ, linea
Usually used for caesarean so incision is from cranial to the umbilicus caudally
Paracostal approach and uses
Incision is made parallel and 5-10cm caudal to the last rib
Layers incised are skin, subcutaneous tissues, aponeurosis of EAO (in the direction of the skin incision), either muscular portion (dorsally) or aponeurosis (ventrally) IAO depending on location, transversus and peritoneum
Usually done on the right for access to the abomasum
Left oblique laparotomy
Done on the left for caesarean
Similar to left flank but angles cranioventrally 45 degress
Can be done standing or recumbent
List the 4 types of Vagus Indigestion (VI)
1) Failure of eructation (free gas bloat, oesophageal obstruction)
2) Abnormality of omasal transport (**TRP**, liver abscess, peritonitis)
3) Pyloric outflow obstruction (RVA, RDA, LDA)
4) VI of late gestation
The most common causes of VI include TRP (hardware dz), reticular abscess (usually involving the medial wall of the reticulum), liver abscesses, pneumonia, postabomasal volvulus, and abomasal ulcers
Describe the papple shaped abdomen
Observe abdominal shape from behind the cow - the ‘papple shape’ is classic for rumen distension - the distended dorsal sac of the rumen occupies the dorsal left flank and the ventral sac of the rumen distends not only to fill the left ventral abdomen but also to distend over into the right ventral abdomen, thus giving an apple shape to the left side and a pear shape to the right side
List 4 causes of left sided pings
- LDA
- Ruman tympany
- Rumen void
- Pneumoperitoneum
List 6 causes of right sided pings
- RVA
- RDA
- Caecal dilation/volvulus
- Gas distension of proximal colon
- SI distension
- Pneumoperitoneum
- Pneumorectum
- Ventral sac of the rumen
Typical location of an LDA ping
How does this differ from a rumen distension ping?
LDA located on a line from TC to elbow in ICS 9-13 usually - forms circular shape
Rumen ping occupies PLF & resonates dorsally
Typical ping location with RDA/RVA
Right ICS 9-13
Area of resonance is usually larger with greater fluid accumulation with RVA vs RDA.
Ping location w caecal dilation/volvulus
How can caecal distension & volvulus be differentiated
Right mid abdomen/PLF extending cranially to ICS 10-11 (ie more caudal vs RVA/RDA which occupies none/less of PLF)
Usually ++ succussion dt caecal fluid accumulation
Cabn be hard to differentiate -
Those w normal HR, some manure production, mild dehydration, & mild-moderate distention of cecum on rectal are more likely to have dilatation & tx conservatively at 1st w fluids & cathartics.
Caecal volvulus typically causes more severe systemic signs incl colic, hypotension, tachycardia, little/no manure production, dehydration, & palpation per rectum of the apex of cecum rotated cranially - indicated need for sx intervention.
Findings often are not straightforward, & decision for sx not easy.
In most instances, a right-sided standing ex lap is indicated because the risk of further compromise of a volvulus of the cecum outweighs benefits of medical tx of moderate-severe cecal distention.
Causes of pings in calves
Pings in pre-ruminant calves are most commonly caused by abomasitis, whereas in ruminant most likely rumenitis, peritonitis, abomasitis, caecal distention, or DA.
The ping in ruminant calves with LDA is often heard more caudally than in adults
With sucussion, fluid distention of a viscus generally causes a different sound than the sloshing heard with acute peritonitis or ascites
Sites for laparoscopic entry to the bovine left flank
- Cranial site = 3-4cm caudal to last rib, 8cm ventral to TPs
- Caudal site = 5cm cranioventral to the distal end of the TC. This site is also used in the RIGHT flank
Main causes of a papple shaped abdomen
Usually dt (but not exclusive) rumen distension assoc w VI
> Failure of eructation
> Omasal transport failrue (TRP)
>Pyloric outflow obstruction
> Late gestation
Causes of ‘apple’ shaped abdomen
= bilateral ventral distension
Usually indicates free abdominal fluid eg uroperitoneum or diffuse peritonitis
More symmetrical distension than with the others
Abdominocentesis for characterisation of fluid and hopefully dx
Possible causes of prominent left dorsal distension & right ventral distension
Free gas bloat
Peri-ruminal abscesses (eg post rumenotomy) - US/centesis for dx
Frequency of normal rumen contractions. How is this assessed?
What are the 2 contraction cycles of the rumen & what is each associated with?
2-3 contractions every 2 mins
Assessed with a fist in the left PLF to palpate contraction
Rumen has 1ary & 2ary contraction cycles
1ary - assoc w mixing ingesta
2ary - assoc w eructation.
Rumination is a specialised form of secondary contraction stimulated by coarse material in the reticulum and rumen.