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.
Label the schematic of cattle GIT
A - ileum
B - Caecum
C - proximal loop of ascending colon (PLAC)
D - spiral colon (centripetal loops going in, fugal loops coming out)
E - distal loop of ascending colon
F - transverse colon
G - descending colon
H - rectum
Treatment options for rectal prolapse
- Submucosal resection: - insert flexible rubber tubing and secure w 2 18g needles at right angles through prolapse and tubing
Make circumferential mucosal incisions in front and behind affected area; join the 2 with a longitudinal incision & dissect the mucosa free & discard. Close remaining mucosal edges at 4 equidistant points then fill in the gaps; 2/0 monofilament absorbable
- Stairstep amputation - tubing & secure as above. Circumferential incision through all layers except inner mucosa. Create plane of dissection caudally between inner mucosa & outer layers. Transect leaving slightly longer mucosal section that can be reflected back & closed to healthy mucosa
Both replaced & purse string for 1 week
Right flank omentopexy technique key points
- 20-cm right PLF incision from 4–5cm ventral to TPs
- When the peritoneal cavity is entered in the case of an LDA, the duodenum will be vertical instead of in its normal horizontal position.
- Palpate left side of abdomen by deflecting greater omentum craniad. Palpate abomasum distended W gas on left side of the rumen. (+/- adhesions).
- Abomasum deflated w 14–16-g needle & sterile tubing.
- Abomasum returned to normal position by following peritoneal surfaces ventrally with the hand between the rumen and the body wall. Once to the left of the rumen, the hand, with the fingers closed, is used to sweep the abomasum back to the right side of the abdomen.
- Gentle dorsocaudal pulling on the omentum, which has also been displaced to the left, is also helpful in this manipulation.
- Once returned to normal position, duodenum resumes its normal horizontal position and is commonly observed to fill with gas. The greater omentum, which is observed through the abdominal incision, also feels loose.
- The omentum is grasped and pulled out through the incision. It is gently retracted dorsad & caudad until the pylorus can be visualised. This fold of omentum may be held by an assistant or attached to the upper part of the skin incision with towel forceps while the anchoring sutures are placed.
- 2 mattress sutures of no. 1 or no. 2 synthetic absorbable suture material (one cranial to the incision and one caudal to it) are placed through the peritoneum and transverse abdominal muscle and through both layers of the fold of omentum
- The sutures are placed about 3 cm caudal to the pylorus. The peritoneum and transverse abdominal muscle are then sutured in a simple continuous pattern with no. 1 or no. 2 synthetic absorbable suture, and the omentum is incorporated into the suture line in the ventral two-thirds of the incision. The internal and external abdominal oblique muscle layers and the skin are closed as in a routine flank laparotomy.
Procedure for left flank abomasopexy
- Std 20-25cm left PLF lap; care re abomasal penetration when entering the abdomen
- Abomasum usually first thing seen at incision, rumen behind it.
- 8-12cm simple continuous or interlocking suture line of heavy polycaprolactam, nylon, or polypropylene, is placed in the greater curvature of the abomasum 5–7 cm from the attachment of the greater omentum (serosa may be rubbed with a dry sponge to enhance adhesion formation). Don’t penetrate lumen
- 1 meter of suture should extend from each end of the suture line, w haemostats on each end for easy identification. Abomasum then deflated w 12g needle & rubber tubing
- Cranial end of suture is attached to a large, straight, cutting needle or to an S-curved cutting needle; this needle is carried along the body wall to a position right of midline, but medial to subcutaneous abdominal vein & 15 cm caudal to xiphoid process.
- The needle is inserted quickly through the ventral body wall w assistant applying upward pressure on abdominal wall in area of penetration. Assistant grasps the needle, & the caudal suture is placed through the body wall 8–12 cm caudal to the cranial suture.
- Assistant grasps the 2 suture ends & applies gentle traction; w surgeon pushing abomasum into normal position, where assistant ties suture ends together
- Suture tension - should fit 1 fifinger snuggly between abomasum & body wall when tied.
- Too loose may allow intestine to become entrapped in the suture loop while too tight may lead to tearing of the suture out of the abomasum.
- Suture left in for 4 weeks; ends are then cut as close to skin as possible.
Procedure for right paramedian abomasopexy
- 20cm incision made between midline & right SQ abdominal vein, starting approx 8cm caudal to xiphoid process ending immediately cranial to umbilicus
- Incision continued through external rectus sheath (aponeuroses of EAO/IAO) & rectus abdominis, to reveal internal rectus sheath (transversus aponeurosis); incised w peritoneum
- In most LDAs, abomasum will return to relatively normal position during casting.
- Once in correct position, lateral aspect of greater curvature (where it is free of omentum) is incorporated with peritoneum & internal rectus sheath in a simple continuous suture pattern with no. 1 or no. 2 synthetic absorbable suture material - DON’T penetrate mucosa.
- External rectus sheath closed w a simple continuous of no. 1 / 2 synthetic absorbable &the skin w Ford interlocking polymerized caprolactam
