Bovine abdominal surgery 1

Question 1

A. PRESURGICAL CONSIDERATIONS

Answer 1

• Decision-making:
  > Financial reality
  > Surgeon capability & facilities
• Patient positioning
• preparation of surgical site
• preparation of surgeon
• Prevention of peritonitis and surgical infection
• Preoperative antimicrobials
• Perioperative analgesics

Question 2

options for patient positioning in bovine abdominal surgery
- is it important?
- considerations for standing?
- when to use lateral recumbency, dorsal recumbency? recumbent consideration?

Answer 2

• Selecting the appropriate incision location is ‘half the battle’ in bovine GI surgery
• Standing with local anesthesia blocks, use small amounts of sedation judiciously as may promote recumbency
• Lateral recumbency for flank (usually standing) and inguinal approaches
• Dorsal recumbency for cranial abdomen and teat surgery
• Padding of bony prominences in recumbent procedures

Question 3

How to prepare surgical site?

Answer 3

• Gross dirt removed
• 25cm hairless area of skin around surgical site (clipped, not shaved)
• Standard scrub as you have been taught already in earlier courses: povidone-iodine, chlorhexidine gluconate or chlorhexidine acetate
• Incision site draped if possible
• Tail tied to hind leg for standing procedures

Question 4

how to prepare surgeon?

Answer 4

• Head covering, facial covering
• Sterile gloves
• Gown

Question 5

considerations for prevention of peritonitis and surgical infection? lavage use?

Answer 5

• Careful planning and adequate restraint
• Prophylactic antibiotics
• Patient risk factors
• Intraoperative gross contamination exteriorized if possible and localised
• Generalised lavage may distribute bacteria more than prevent infection

Question 6

how to use preoperative antibiotics? when? which ones?

Answer 6

• Prophylaxis – at surgical site at time of incision – so give 60 minutes prior
• If uncomplicated, clean and no break in sterility, further antibiotics not necessary
• Ceftiofur and penicillin commonly used in Canada (do not use ceftiofur for prophylaxis in United States)

Question 7

use of penicillin and ceftiofur as preoperative antibiotics- when is each appropriate? other options and considerations?

Answer 7

o Penicillin better against anaerobes than ceftiofur, but not very effective against gram negative organisms, longer milk and meat withdrawal than ceftiofur
o Ceftiofur sodium or ceftiofur hydrochloride – check labeled dose and meat and milk withdrawal times
 Sometimes penicillin and ceftiofur combined eg if enterotomy performed to allow for broad-spectrum coverage
 Oxytetracyline also an option but disadvantages are that bacteriostatic and potential for renal failure if given to dehydrated animal

Question 8

perioperative analgesics - why to use, which ones?

Answer 8

 Indicated for welfare (pain, improved appetite, general well-being), decrease swelling, anti-inflammatory
o Flunixin meglumine most commonly used
o Lidocaine, alpha agonists and butorphanol are alternatives
 Check milk and meat withdrawals

Question 9

ruminant stomach - compartments? which are glandular? at 18 months, how much total stomach capacity does each comprise?

Answer 9

 Ruminant stomach is one compartmentalized complex stomach:
o 3 non glandular compartments:
 rumen, reticulum, omasum)
o 1 with glandular mucosa (abomasum)
 18 months the compartments have reached the following approximate percentages of total stomach capacity:
o Rumen 80%; reticulum 5%; omasum 7%; abomasum 8%.

Question 10

rumen capacity?

Answer 10

 Rumen: capacity is 102-148L!

Question 11

rumen location? orientation to other organs? relationship to reticulum? structure?

Answer 11

o Lies against left and ventral abdominal wall
o Visceral surface contacts liver, intestines, omasum and abomasum
o Very wide orifice with reticulum, leading to some calling it the ruminoreticulum
o Surfaces divided by right and left longitudinal grooves, connected by cranial and caudal grooves into a dorsal sac and ventral sac
o Dorsal sac has large gas bubble
o Ruminoreticular groove forms the internal ruminoreticular fold
o External grooves of the rumen correspond to internal muscular pillars of the same name

Question 12

reticulum orientation, relationship to other organs and stomach compartments

Answer 12

o Cranial diaphragmatic surface in contact with diaphragm and left lobe of liver
o Caudal surface contacts rumen, omasum and abomasum

Question 13

what is grastric groove?

Answer 13

o Shortest route between esophagus and pylorus
 Reticular groove, omasal groove, abomasal groove

Question 14

omasum orientation, relationship to other organs and stomach compartments

Answer 14

o Lies on the right of the floor of the intrathoracic part of the abdomen
o Base of omasum contacts the reticulum, rumen and abomasum

Question 15

Abomasum orientation, relationship to other organs and stomach compartments

Answer 15

o Greater curvature lies on ventral abdominal wall
o Caudal part of greater curvature separated from intestines by greater omentum
o Pyloric sphincter can close off flow from abomasum to duodenum

Question 16

position and orientation of the omentum
- where does it adhere?

Answer 16

o Greater omentum has superficial wall and deep wall and forms omental bursa
o On right side, it adheres to the duodenum, starting at the cranial flexure and extending to the caudal flexure
o The deep wall of the greater omentum passes from the duodenum, ventral to the intestines, to the attachment on the right longitudinal groove of the rumen
o The superficial wall passes ventral to the intestine and the ventral sac of the rumen to the left longitudinal groove

Question 17

where do the intestines lie in the abdominal cavity?

Answer 17

o Lie in right side of abdominal cavity
o Most are attached by mesentery and lie in the omental recess

Question 18

duodenum position and orientation

Answer 18

o from pylorus runs dorsally to liver (cranial part), here it forms the sigmoid flexure and turns caudally to continue as descending duodenum until it reaches tuber coxae, here it turns sharply medially around caudal border of the mesentery and continues cranially as the ascending duodenum

Question 19

jejenum anatomic location and features? ileum?

Answer 19

 Jejunum runs with a short mesentery with many loops into the ileum.
o The caudal part of the jejunum has a longer mesentery called the flange.
o The ileum attaches to the ileocecal fold, and runs alongside the cecum.
o The jejunum surrounds the spiral colon like a wreath.
o The ileum opens into the large intestine at the cecum.

Question 20

large intestine includes what structures?

Answer 20

the cecum, colon and rectum

Question 21

how long is the cecum? where is it an what is its relation to other structures?

Answer 21

o Cecum is 50-70 cm long.
* Lies dorsally in right abdomen
* extends to pelvic inlet with a blind apex
* is continuous with the colon with no change in lumen size

Question 22

colon components and their features and anatomical position

Answer 22

• Lies dorsally in right abdomen
• extends to pelvic inlet with a blind apex
• is continuous with the colon with no change in lumen size

Question 23

considerations for deciding your approach for exploration of the abdomen

Answer 23

• Consider the disease process and which organ you need to access, the value of the animal, the available facilities, temperament of patient and experience of the surgical team

Question 24

what location is best to use for surgical abdominal exploration

Answer 24

• The right paralumbar fossa is best for surgical exploration

Question 25

Using a right paralumbar fossa approach:
o Outside of the omental sling, in the cranial abdomen, the following structures can be palpated:

Answer 25

duodenum, abomasum, including pylorus, fundus and body, liver and gall bladder, omasum, reticulum and kidneys

Question 26

Using a right paralumbar fossa approach:
o Inside the omental sling the following can either be exteriorised, or palpated:

Answer 26

o Jejunum, ileum, cecum, parts of proximal and distal loop of ascending colon (see diagram), parts of spiral colon, parts of descending colon

Question 27

from a right paralumbar fossa approach, which structures can be exteriorized through the excision?

Answer 27

• cranial duodenum
• descending duodenum
• jejunum
• ileum
• cecum
• spiral loop of ascending colon
• proximal loop of ascending colon
• part of distal loop of ascending colon, part of descending colon

Question 28

from a right paralumbar fossa approach, which structures cannot be exteriorized through the excision, but can be palpated?

Answer 28

• abomasum
• part of cranial duodenum
• part of jejunum
• part of spiral colon
• part of descending colon
• part of rectum

Question 29

from a right paralumbar fossa approach, which structures cannot be exteriorized through the excision, and cannot be palpated?

Answer 29

• part of ascending duodenum
• part of distal loop of ascending colon
• transverse colon