large animal orchiectomy

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.