LEC 2 - GI Surgery

Question 1

What level of contamination should routine gastrointestinal surgery be considered?

Answer 1

Routine gastrointestinal surgery is generally considered to be clean- contaminated. Routine prophylactic antibiotics should be used

Question 2

What effect will the hot lights of the surgery suite have on abdominal tissue?

Answer 2

The hot lights from the surgery suite may result in desiccation of the tissue. As such, it is important to remember to keep tissue moist using a balanced electrolyte solution throughout a long procedure.

Question 3

What technique is performed to prevent open intestinal contents from spilling into the abdomen during surgery?

Answer 3

“Packing off” the surgical field using moist laparotomy pads around the exteriorized bowel helps prevent contamination.

Question 4

At the end of any gastrointestinal surgery, what procedures must be done prior to closure?

Answer 4

The abdomen should be lavaged thoroughly to dilute and wash away any contamination that may have spilled into the peritoneal cavity. Always count sponges and check your incisions/ligatures for bleeding prior to closure.

Question 5

What suture is generally recommended for GI surgery? What suture is not recommended?

Answer 5

Synthetic, absorbable monofilament suture is generally recommended. Catgut and non- absorbable braided suture are not advised.

Question 6

What is the preferred
location for performing a
gastrotomy to remove a
foreign body in small
animals?

Answer 6

Wherever there is a non-vascular region in the stomach

Question 7

When should food be re- introduced to a small animal patient that just had surgery on the stomach such as a foreign body removal?

Answer 7

Feed a bland, soft diet 12-24 hours post-op if not vomiting. May need to add a central-acting anti-emetic.

Question 8

When closing a gastrotomy incision in a small animal, what are the preferred layers of closure and patterns?

Answer 8

The stomach may be closed as 1 layer, but is more commonly closed in 2 layers:
• Mucosa/submucosa – simple continuous
• Muscularis/serosa – simple continuous or inverting pattern

Question 9

What bacterial organisms are of most concern for possible infection when performing a gastrotomy on a small animal patient?

Answer 9

Other than Helicobacter, there are very few bacterial organisms that can survive the acid environment of the stomach. Helicobacter rarely causes systemic infections.

Question 10

What are some of the signs of gastric wall devitalisation that a surgeon should look for?

Answer 10

Absence of peristalsis Green-grey serosal color Thin gastric wall. Poor perfusion

Question 11

Name 3 types of obstruction of the small intestine

Answer 11

• Simple obstruction
• Strangulating obstruction
• Non-strangulating infarction/thrombosis

Question 12

By what mechanisms do injury of the small intestine occur?

Answer 12

• Luminal distention

* Mucosal ischemic injury • Reperfusion injury

Question 13

When suturing small intestine in small animals, how far should the sutures be placed apart and from the cut edge of intestine?
What considerations should be taken when choosing a suture pattern?

Answer 13

Sutures should be 3-4mm from the cut edge of the intestine and 2- 3mm apart.
Inverting suture patterns will result in a decreased luminal diameter
Everting patterns may encourage adhesion formation
Simple interrupted sutures are therefore recommended.

Question 14

When performing an enterotomy to remove a foreign body, where should the enterotomy incision be made?

Answer 14

Enterotomy incisions should always be made at the anti-mesenteric surface, distal to the foreign body to prevent incising through potentially compromised tissue.

Question 15

How much tensile strength does the intestine regain as it heals?

Answer 15

• ~70% of its original tensile strength by 10-
14 days.
• Nearly 100% by 3
weeks.

Question 16

Small bowel syndrome generally will occur after excising how much intestine in small animals?

Answer 16

After ~75% of the intestine is removed, small bowel syndrome may occur. This results in chronic maldigestion/malabsorption and diarrhea. It may be life threatening.

Question 17

What technique using another section of the GI tract may be employed if leakage from an intestinal incision is suspected to possibly occur?

Answer 17

Serosal patching – this involves suturing a section of healthy intestine over a section of damaged intestine to reinforce the closure by creating an adhesion.

Question 18

What non-intestinal tissue will help improve blood flow to a sutured enterotomy incision and thus assist in healing?

Answer 18

Omentalisation – following an incision in the intestine, the omentum is draped (or sutured) across the incision prior to closure. The omentum will provide blood supply to the tissue, improve drainage through its lymphatics, and help plug any small defects in the serosa.

Question 19

What are some of the concerns regarding healing of incisions in the colon?

Answer 19

Increased risk of infection
• Slower healing than SI
• Slower return of wound
strength
 • Non-segmental blood supply like the small intestine

Question 20

What should be done to the segments of the intestinal tissue prior to performing an anastomosis?

Answer 20

Intestinal contents should be “milked” away from the ends to reduce spillage and Doyen clamps should be applied to also prevent spillage.

Question 21

What size suture is advised to use for performing surgical procedures on the gastrointestinal tract of dogs? Cats?

Answer 21

dogs: 3-0 or 4-0 Cats: 4-0 or 5-0

Larger sizes may cause trauma to the tissue and blood supply

Question 22

What are some of the techniques for anastomosis of two ends of intestinal lumen that are of grossly different diameters?

Answer 22

• Spatulate the smaller diameter lumen
• Partially close the larger diameter lumen
• Use a stapling device (create a side to side anastomosis)

Question 23

Describe two methods of surgically biopsying the intestinal tract

Answer 23

1. Excising an elliptical section (longitudinal direction) of the anti-mesenteric border and suturing closed
2. Using a 4mm or 6mm biopsy punch and suturing closed

Question 24

If you suspect bowel leakage following GI tract surgery, what parameters will help you determine whether this is in fact so, and what will you expect to find?

Answer 24

• Temperature
• Abdominal palpation
• Attitude
• Incision appearance
• CBC
• Glucose
• Radiographs/ultrasound • Abdominocentesis
• Peritoneal lavage