Lecture 22: Principles of LA Soft Tissue Surgery

How is LA tissue different than SA?

• thicker tissue

• skin does not bruise

• hemorrhage generally not a problem

What is the acceptable blood loss for horses during sx?

< 15% = no clinical signs, about 6L in 500kg horse

What percent of a horses body weight is their blood volume?

8%

What are the benefits of standing surgery for horses?

• Prevents complications of being recumbent

• Prevents risk of recovering from anesthesia

• Better access for select structures (Dorsal)

• Reduced cost

What are the benefits of equine recumbent surgery?

• safer for surgeon

• no movement = better control of surgical field

• better access for most structures

What are A, B, and C?

sinus trephination sites

What are the considerations for healing from equine URT sx?

• mucosa heals rapidly

• potential for mucosal “webbing” (requires later revision)

What are the common complications of URT surgery?

• excessive swelling that blocks airway

• damage to nearby structures (cranial nerves)

• surgeries that are (re)opening airway

  • too large of opening → aspiration

  • too small of opening → problem not corrected

• sx site infection

What diagnostics are included in a “colic work up”?

• Rectal palpation

• Abdominal U/S

• Abdominal radiographs

• Nasogastric tube intubation

• Abdominocentesis

• Bloodwork

What are the approaches for a celiotomy?

Ventral midline – most common

Paramedian – right side

Paralumbar fossa - uncommon

Laparoscopic portals

What are the common GI procedures done in LA?

• exploration

• de-rotation

• enterotomy

• resection and anastomosis

• biopsy

What is the major cause of post-operative colic and death after GI surgeries?

intra-abdominal adhesions - a dysfunction of fibrinolysis

What are the ways to reduce intra-abdominal adhesions?

• Gentle handling of tissues – avoid excessive handling

• Keep tissues moist

• Use of lubricants (carboxymethylcellulose)

• Strict asepsis

• Prevent blood from entering abdomen - Flush abdomen if needed!

• do NOT use dry gauze EVER

What are the most common post-surgical complications after a GI procedure in horses?

• adhesions

• hemoabdomen

• peritonitis

• ileus

• diarrhea

• endotoxemia

• incisional infections

What are the common urogenital procedures in male horses?

• castration

• cryptorchid castration

• urolithiasis

• penile injuries & problems

• preputial injuries & problems

• inguinal hernia

What are the common urogenital procedures in female horses?

• repair foaling injuries

• correct vaginal conformation

• ovariectomy

What is the common urogenital procedure in foals?

bladder rupture

What are the different approaches for an equine ovariectomy?

• Laparoscopy

• Flank

• Vagina

• Ventral midline celiotomy

What special surgical considerations need to be evaluated for equine urogenital procedures?

• may need to catheterize bladder

• function is important outcome

• challenging approaches: small spaces, bladder difficult to access in adult horse

What considerations for healing need to be evaluated for equine urogenital procedures?

• stricture formation or breakdown of repair

• back end of mare has a lot of contamination = repair breakdown common

• can create a perineal urethostomy to give distal urethra a rest

What are the common uses for equine laparoscopy?

• cryptorchidectomy: usually done in dorsal recombency, but can be done standing; trendelenburg position

• ovariectomy: usually done standing

• explore abdomen in chronic cases: usually done standing

What are the pre-operative considerations for laparoscopic procedures in equids?

• withhold feed: space in abdomen, less weight on diaphragm if in Trendelenburg position

• NSAIDs

• Antibiotics

What are the general complications associated with equine laparoscopic procedures?

• subcutaneous emphysema

• retroperitoneal insufflation

• bowel perforation

• hemorrhage: body wall incisions, mesovarium or mesorchium, ligature slippage

How is a laparoscope placed?

1. abdomen insufflated with CO2 (8-12 mmHg)

2. blind stab incision made to place scope portal

3. scope introduced through portal that maintains pressure in abdomen

4. remaining portals created with visualization from scope: generally need 3 total- 1 scope & 2 instrument portals