large animal orchiectomy
DESCRIPTION
Powerpoint complimenting written lecture notes discussing equine and food animal castration, surgical considerations, and complications. Prepared for lecture to 2nd year veterinary students.TRANSCRIPT
Large Animal Orchiectomy(Castration Lecture)
Dane Tatarniuk, DVMResident, Large Animal Surgery
April 5th, 2013
Terminology
• castration, • orchiectomy, • emasculation, • gelding, • cutting,
Equine Castration
• Overview– Age– Indication for surgery• Behavior• Neoplasia• Inguinal herniation• Testicular trauma
Anatomy
• Scrotum• Testicle• Epididymis• Tunica
Vaginalis– Parietal Tunic– Visceral Tunic
• Inguinal Canal
Anatomy
• Spermatic Cord• Cremaster Muscle
Pre-operative Considerations
• Systemically healthy• Palpation– Two testicles descended?
• Vaccination– Tetanus
• NSAIDs– Bute, Banamine
• Antibiotics– Penicillin, Ceftiofur
Supplies
• General instrument pack • Sterile gloves • Scrub • Emasculators • Suture • Ropes • Towels • +/- IV catheter
Standing Castration• Advantages
– Less cost & assistance– Quicker– Choice if poor anesthetic candidate
• Disadvantages– Vulnerable position– Avoid on small horses, donkey’s, mules– Assess temperament prior
• Sedation– Alpha-2 agonist +/- butorphanol
• Local Analgesia– Essential to castrating standing– Spermatic cord or intra-testicle
• Position– Tight to horse, keep head up, use reach of arms.
Recumbent Castration
• Environment– Field conditions– Hospital conditions
• Anesthesia • Xylazine followed by
ketamine & diazepam
• Recumbancy– Left lateral vs. dorsal
• Rope Restraint– Tie the limbs to
maintain safety
Open Castration
• Incision– Through both scrotum and
parietal tunic• Dissection
– Ligament of tail of epididymis• Exteriorization
– Testicle and spermatic cord• +/- Ligation
– Hemostasis– Foreign material
• Emasculation• Leaves parietal tunic behind
Emasculation
• “Nut to Nut”• Held clamped for
minimum of 1 minute– Anecdotal rule of ‘1
minute per age year of horse’ often used
• Variable types of emasculators– Serra, White vs. Reimer
Closed Castration
• Incision– Only through scrotum, not
through parietal tunic• “Stripping”
– Dissection of scrotal fascia• Emasculation
– Parietal tunic vs. Cremaster muscle
• +/- primary closure– Decrease risk of herniation
and evisceration – Foreign material
Semi-Closed
• Incision– Scrotum– 2cm incision into parietal
tunic• Eversion of tunic
– Flip parietal tunic over thumb– Provides grip to aide in
retraction• Closed castration
– Emasculate spermatic cord followed by parietal tunic
Scrotal Healing
• Second Intention Healing– Drainage– Stretching incision– Trim excess fascial tissue
• Primary Closure– Technique
• Excellent hemostasis
– Environment• Sterile operating conditions
– Increased cost
Other
• Already anesthetized• Remove wolf teeth– 505 & 605
• Interfere with bit placement in the mouth
Post-Operative Recommendations
• Open Scrotal Incision– Movement
• Lunging at the trot daily
– Hydrotherapy• Decrease swelling
• Closed– Confinement to facilitate primary intention healing
• Isolation from mares– Active spermatozoa – 2 days min.
Complications
“The one who does not operate, does not have complications.”
Hemorrhage• Emasculator application
– Thick cords– Angle non-perpendicular– Instrument condition
• Testicular Artery– Some dripping normal, from scrotal vessels– Active stream of blood is not normal
• Treatment– Wait 20 – 30 min, observe– Sedate, re-grasp cord, ligate– Pack with gauze for 24 hours– Anesthetize and find bleeder
• Monitor yourself– Stay on farm or refer
Evisceration
• Prolapse of intestine / omental tissue through inguinal canal and scrotum
• Breed– Standardbreds, Drafts
• Clean and replace contents back into abdomen– May have to anestheize– Refer immediately
• Sequela– Strangulation of intestine– Septic peritonitis
Edema
• Common, normal result• Management– Exercise– Hydrotherapy
• If non-responsive,– Re-open scrotal incision– Promote further
drainage
Septic Funiculitis
• Definition: Infection of spermatic cord
• Open castration– More tissue left behind
• Treatment– Antibiotics– Drainage– Surgery
• Champignon vs. Scirrhous Cord – Streptococcus vs.
Staphylococcus
Clostridial Infection
• Clostridium tetani– Spastic paralysis
• Clostridium botulinum– Flaccid paralysis
• Malignant Edema– Tissue necrosis, cellulitis, fever, depression,
toxemia, death • Poor prognosis
Septic Peritonitis
• Anatomy– Vaginal cavity communicates
with abdomen• Treatment– NSAIDs– Antibiotics– Peritoneal Lavage
• Referral
Penile Damage
• Inadvertent emasculation of penis• Edema formation• Paraphimosis• Know your anatomy
Hydrocele
• Scrotal swelling– Excess abdominal fluid in vaginal cavity
• Open castration• Cosmetic problem– Usually painless
• Drainage not helpful– More abdominal fluid– Can introduce bacteria
• Surgery– Remove parietal tunic
Behavior
• Perpetual masculine behavior• Learned response• Older stallions• Warm owners
Cryptorchidism• Definition: Failure of one or more
testicles to descend• Location
– Abdominal vs. inguinal– Left vs. right
• Inherited• Diagnostic techniques
– Palpation, ultrasound, exploratory, hormone assays
• Surgical removal– Do not remove a descended testicle
if the other testicle cannot be located.
Food Animal
• Principles of castration similar to equine
• Meat quality, behavior• Often performed by producer• Restraint alone vs.
sedation/anesthesia• Scrotal incision
– Overlying testicle– Transect distal 1/3rd
• Strip, +/- ligate, emasculate, etc.
Food Animal Tools
• Newberry knife– Splits scrotum in half– Good access– Good drainage
Food Animal Tools• Bloodless Castrators
– Elastrator– Callicrate
• Strangulation of vasculature -> atrophy -> necrosis• ~ 3 weeks• Small, young animals
Food Animal Tools
• Burdizzo– Crushes spermatic
cord from the outside
– May have to apply multiple times
– Testicles atrophy, don’t usually slough
Food Animal Tools
• Henderson castrating tool– Attached to power drill– Twisting motion– Good hemostasis in older animals
Conclusion
• Understand the anatomy, know your basic surgical principles, and evaluate the unique factors present (specie, purpose of animal, animal temperament, surgical environment, owner expectations, owner budget etc.)
• Recognize potential complications from castration and know how to manage them appropriately.
• There is no “one right way” to perform castration - the right way is to know every way and apply the appropriate technique to the individual / situation.