Cryptorchid surgery and simple ophthalmic procedures (Proceedings)

Cryptorchid Surgery

Cryptorchism is defined as the failure of one or both testicles to descend into the scrotum. The cryptorchid testicle can be located anywhere along the path from the area of fetal development of the gonads (just caudal to the caudal pole of the kidney) to the subcutaneous tissue between the external inguinal ring and the scrotum. Thus a cryptorchid testicle can be located in the abdominal cavity, in the inguinal canal, or in the subcutaneous tissue between the external inguinal ring and the scrotum.

Diagnosis

Testicles should be easily palpated in the scrotum of dogs and cats greater than 2 - 4 months of age. If one or both testicles are not located in the scrotum careful palpation will reveal which testicle(s) are involved and whether the testicle(s) are located in the subcutaneous tissue. Failure to palpate a testicle in the scrotum or the subcutaneous tissue leads to a presumptive diagnosis of abdominal cryptorchidism. Palpation of the testicle in the subcutaneous tissue leads to a diagnosis of subcutaneous cryptorchidism.

Surgical Technique

Subcutaneous cryptorcidism. If the cryptorchid testicle is palpated in the subcutaneous tissue, incision directly over the testicle will allow exposure and removal of the testicle.

Abdominal cryptorcidism. Locating an abdominal testicle is generally very easy. The critical factor to remember is that both ductus deferens enter the urethra at the prostate. If you trace the ductus deferens from the prostatic urethra cranially it is located dorsal to the bladder until it passes the junction of the ureter and the bladder. Cranial to the point where the respective ureter enters the bladder the ductus deferens turns laterally on its course to the testicle. This anatomical feature makes it extremely easy to find an abdominal testicle.

In the dog the skin incision is made in the caudal abdominal skin just lateral to the prepuce on the side of the cryptorchid testicle. Entry into the abdomen is on the midline through the linea alba by undermining under the prepuce to the midline. Incising the linea alba allows exposure of the urinary bladder. Caudal reflection of the urinary bladder, exposing the dorsal surface of the bladder, will allow visualization of both ductus deferens. Gentle retraction of the ductus of the cryptorchid testicle will allow delivery of the testicle into the surgical site, ligation of the testicular vessels and excision of the testicle.

In the cat the skin incision is made in the caudal abdominal skin on the midline. Entry into the abdomen is on the midline through the linea alba and allows exposure of the urinary bladder. Caudal reflection of the urinary bladder, exposing the dorsal surface of the bladder, will allow visualization of both ductus deferens. Gentle retraction of the ductus of the cryptorchid testicle will allow delivery of the testicle into the surgical site, ligation of the testicular vessels and excision of the testicle.

On occasion cryptorchid testicles are trapped between the muscles layers in the inguinal canal. When this occurs gentle tension on the ductus deferens will allow visualization of the ductus deferens entering the inguinal canal. Gently teasing the musculature of the internal inguinal ring apart with a blunt instrument is often enough to allow delivery of the testicle back into the abdomen for removal.

Frequently cryptorchid testicles are smaller than normal and it is possible that the cryptorchid testicle will be in the subcutaneous tissue but not be palpable. Entry into the abdomen, assuming abdominal cryptorchidism, would, therefore, fail to reveal the cryptorchid testicle. Gentle tension on the ductus deferens would confirm that the ductus deferens passes through the inguinal canal. The caudal abdominal skin incision is of value here, as from that incision you can undermine the skin between the incision and the external inguinal ring. Gentle traction on the abdominal ductus will allow you to locate the ductus deferens as it exits the inguinal canal and will lead you to the cryptorchid testicle.

Once the cryptorchid testicle is located, either in the abdomen or the subcutaneous tissue, it can be excised using any standard technique. For very small testicles with small vessels and a small ductus deferens I will use the figure eight knot in the spermatic cord. For larger testicles, with larger spermatic cords I will clamp the spermatic cord with hemostats, transect distal to the most distal hemostat and place a ligature using Miller's knot in the area of the spermatic cord crushed by the most proximal hemostat. In dogs weighing over 18 kg, I will clamp the spermatic cord with three hemostats, transect distal to the most distal hemostat, place a ligature using Miller's knot in the area of the spermatic cord crushed by the most proximal hemostat, and a transfixation ligature in the area of the spermatic cord crushed by the second hemostat.

Simple Ophthalmic Procedures

Often a very simple ophthalmic procedure can turn an unadoptable dog or cat into an excellent candidate for adoption. Entropion and ectropion repair, correction of prolapse of the third eyelid, excision of small eyelid tumors, resection of nasal skin folds and enucleation are all surgeries that can be done in the shelter surgery suite. A few special instruments, understanding of the anatomy and the procedures and the willingness to try are all that is necessary.

Special Instrumentation

Attempting ophthalmic surgery without instruments specifically designed for ophthalmic procedures can be very frustrating. However a very small number of special instruments will allow you to do orbital, conjunctival, eyelid and third eyelid surgeries with ease.

The basic ophthalmic pack should contain a Bard Parker scalpel handle, Bishop Harmon forceps, Stevens tenotomy scissors (curved), a small curved Metzenbaum scissors, a Wescott tenotomy scissors, a Derf of Webster holder, a 19 gauge irrigation cannula, Barraquer eyelid specula (various sizes), a Jaeger Lid Plate, and a Desmarres Chalazion forceps.

Additional surgical supplies should include, Weck Cell™ surgical sponges, irrigation solution, and 2-0 to 8-0 absorbable and non-absorbable suture material.

Patient Preparation

Extreme care must be taken to avoid irritation of the cornea and conjunctiva. Patient preparation should consist of clipping eyelashes, shaving the lids (if necessary), and gently removing any debris from lids using dilute baby shampoo (1:10 dilution). In addition, gently flush the cornea and conjunctiva with eyewash. If performing adnexal surgery the cornea should be lubricated. A dilute Betadine™ solution (1:30 to 1:50) is recommended for all ocular surfaces. DO NOT USE Betadine scrub as it is toxic to the cornea.

Ophthalmic Procedures

Temporary Tarsorrhaphy

A temporary tarsorrhaphy may be used in cases of acute traumatic proptosis, as an adjunct to conjunctival flap surgery, recurrent corneal erosions, facial nerve paralysis or any condition that results in exposure keratitis. Most commonly it is used in an effort to save the eye after acute proptosis. It is not a treatment for deep or infected corneal ulcers as it does not provide adequate support, impedes penetration of medications and prevents observation of the eye.

A temporary tarsorrhaphy is performed simply by suturing the upper and lower lids together. 4-0 to 6-0 suture should be placed in a horizontal mattress pattern, through soft rubber stents, and split the thickness of the lids. The sutures should be tied with only enough tension to provide good lid apposition.

Post-operative care depends somewhat on the underlying condition being treated, but typically consists of topical antibiotic ointment, systemic antibiotics, and suture removal in 7 – 14 days. Steroids may be used when severe tissue swelling is present and infection is absent.

Third Eyelid Flap

The third eyelid flap, like the temporary tarsorrhaphy, serves as a physiologic bandage in the case of corneal trauma. Like the tarsorrhaphy it, also, should not be used in deep or infected corneal ulcers or descemetoceles. A third eyelid flap is performed by passing a suture through the upper eyelid in the dorsolateral conjunctival fornix, into the external surface of the third eyelid capturing the cartilage, but not penetrating full thickness, and back through the dorsolateral conjunctival fornix. Tying the suture in a bow over a stent allows for temporary release of the flap and visualization of the cornea.

Lateral Canthoplasty

A lateral canthoplasty is used to permanently reduce the palpebral fissure. It is most often performed in brachycephalic dogs with a tendency to ophthalmic proptosis. The lid margins near the lateral canthus should be incised for 3 – 4 mm and sutured with a two layer closure. 5-0 or 6-0 suture is placed in a continuous pattern in the conjunctive and in an interrupted pattern in the skin. Topical antibiotics and an E-collar should be used postoperatively. Sutures can be removed in two weeks.

Medial Canthoplasty

A medial canthoplasty is used to correct lagophthalmos or medial entropion. Again it is most often performed in brachycephalic dogs, especially Shih Tzu, Lhasa, Pug, and Pekingese breeds. The eyelid margins are incised for 3 – 4 mm. On the lower lid begin the incision 1 – 2 mm medial to the lacrimal puncta. If needed the upper puncta can be sacrificed. Closures and postoperative care are essentially the same as with the lateral canthoplasty.

Skin Fold Resection

Skin fold resection is performed most often in brachycephalic breeds with trichiasis from nasal folds. The surgery is often combined with medial canthoplasty and / or entropion repair. The excessive nasal skin is excised with curved Metzenbaum scissors. Skin is closed with 4-0 or 5-0 non-absorbable suture in a simple interrupted pattern. Post-operative care consists of systemic antibiotics and the placement of an E-collar. Sutures should be removed in 14 days.

V-Lid Resection

A V-Lid resection is indicated in the removal of small eyelid tumors or in some cases of ectropion. The affected lid margin can be grasped with a chalazion clamp and cut with a tenotomy scissors or incised with a scalpel while protecting the cornea with a lid plate. Create margins of at least 1 mm. In most animals you can excise up to 25% of the lid without creating any problems. Closure should be in two layers with 5-0 or 6-0 absorbable suture in the tarsoconjunctiva and nonabsorbable suture in the skin. A figure 8 suture can be placed at the eyelid margin. Postoperative care consists of topical antibiotics and an E-collar. Sutures can be removed in 7 to 10 days.

Eyelid Laceration Repair

Repairing a lacerated eyelid uses the same principles as the V-lid resection. Minimal debridement is required and the lid margins must be precisely apposed.

Entropion Repair

Entropion is a condition in which the eyelid margins (upper, lower, or both) are inverted resulting in corneal irritation from eyelashes. Entropion should always be surgically corrected if it results in other ocular conditions (keratitis, corneal ulcers, conjunctivitis, epiphora). The modified Hotz-Celsus technique consists of excision of enough skin and orbicularis oculi m. to slightly evert the eyelid. An incision is made 1 – 2 mm from the lid margin for the full length of the affected segment of the lid. An elliptical section of skin and muscle is removed depending on the extent of the entropion. Wound closure is accomplished with 4-0 to 6-0 suture in a simple interrupted pattern. It is best to place the most central aspect of the wound first. Postoperative care consists of topical antibiotics and E-Collar. Sutures should be removed in 7 to 10 days.

Third Eyelid Gland Replacement

Prolapse of the gland of the third eyelid can be corrected by the Morgan pocket-flap technique. The third eyelid is everted and stabilized with stay sutures. The use of a lid plate stabilizes the tissue while making two incisions one above and one below the prolapsed gland. A pocket is created for the gland using tenotomy scissors. The gland is placed into the pocket and the wound edges sutured with a continuous pattern of 5-0 or 6-0 absorbable suture with the knots buried or placed on the palpebral surface of the third eyelid. Postoperative care consists of topical antibiotics and placement of an E-Collar. The patient should be rechecked in 1 week or sooner if complications arise.

Enucleation

Enucleation, like amputation, should always be a last resort. But sometimes it is the only option left for animals with blind, painful eyes, intraocular neoplasia, phthisis bulbi, or ocular proptosis. The simplest method is the transconjunctival technique. A lateral canthotomy is performed. The bulbar conjunctive is incised at the 12 o'clock potion with a Steven's tenotomy scissors. The incision is extended for 360 degrees around the limbus and dissected posteriorly to expose the insertions of the extraocular muscles. These muscles are transected at their insertions and the optic nerve is transected posterior to the globe. Avoid putting tension on the optic nerve. After excising the globe, remove the third eyelid and gland, eyelid margins, conjunctiva and lacrimal puncta. Generally a 3 layer closure is indicated with 4-0 or 5-0 absorbable suture in the periorbita and subcutaneous tissues and 4-0 to 5-0 non-absorbable suture in the skin. Postoperative care consists of systemic antibiotics and NSAIDs for pain. Sutures should be removed in 10 – 14 days.

Conclusion

Often animals with ophthalmic problems are considered unadoptable because the conditions are considered too difficult to treat, too unsightly, or too expensive. But for several conditions a one-time investment in some special instruments and a little practice can turn an "unadoptable" animal into a loving pet. The procedures described are simple, straightforward, not very time consuming and very rewarding.