Scrotal Approach to Canine Orchiectomy

PROCEDURES PRO h SURGERY h PEER REVIEWED

Brian A. DiGangi, DVM, MS, DABVP Matthew Johnson, DVM, MVSc, DACVS (Small Animal) Natalie Isaza, DVM University of Florida

Both prescrotal and perineal In a study comparing postoperative approaches to castration of adult complications of adult dogs cas- dogs have been described in the lit- trated through prescrotal and scro- erature. The prescrotal technique tal approaches, no difference in the The scrotal can be used more frequently occurrence of hemorrhage, pain, or approach had because it is easier to exteriorize swelling was noted 72 hours after the testicles and spermatic cords.1 the procedure.10,11 The scrotal significantly A scrotal approach is preferred for approach had significantly reduced reduced odds of castration of cats, small mammals, odds of self-trauma and a 30% large and small ruminants, horses, reduction in surgical time.10,11 In the self-trauma and a and pigs.1-6 A scrotal approach for authors’ clinical training program, 30% reduction in castrating adult dogs has also been junior and senior veterinary stu- used to safely castrate dogs of any dents have performed 984 scrotal surgical time. age.7,8 In dogs, this approach offers castrations in adult dogs between advantages that include improved 2010 and 2014. A total of 11 postop- cosmesis and decreases in anes- erative complications were identi- thetic and surgical times, incision fied, all the result of factors length and subsequent surgical independent of the surgical trauma, postoperative discomfort approach (eg, postoperative hemor- and self-trauma, and scrotal hema- rhage caused by incomplete ligation toma formation.7-11 of the spermatic cord).

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The postoperative environment CONTRAINDICATIONS TO should also be assessed. Because SCROTAL APPROACH FOR of the anatomical position of the ELECTIVE CANINE canine scrotum, the scrotal inci- CASTRATION sion site could come into contact with the ground when the patient h Bilateral cryptorchidism is in a sitting or lying position. A h Pyoderma, trauma, abscessation, clean, dry environment for at least or ischemia of scrotal tissue the first 3 postoperative days is recommended to minimize the h Known unsanitary postoperative environment occurrence of surgical site contamination (see Contraindica- tions to Scrotal Approach for Elective Canine Castration). Patient Selection Patients selected for scrotal castra- Benefits & Drawbacks tion should undergo the same A scrotal approach to canine castra- screening as for any other elective tion can be performed on any dog surgical procedure; they should be for which prescrotal castration is free from severe systemic disease appropriate. In the authors’ experi- that would prohibit administra- ence, the procedure carries the tion of anesthesia, and caregivers benefits of reduced time to locate, must be willing to provide stan- manipulate, and isolate the testicle dard postoperative care. Removal prior to the initial incision as well of cryptorchid testicles should not as reduced time in closing the inci- be attempted via a scrotal sion. In most cases, incision length approach; however, in dogs with is smaller than in prescrotal castra- unilateral cryptorchidism, the tions because of the increased fully descended testicle may mobility and maneuverability of the be removed via a scrotal approach. testicle in the scrotal (vs prescrotal) Other contraindications to the scro- position. In addition, the scrotal tal approach include pyoderma, skin is more elastic, allowing for abscessation, trauma, or ischemia easier exteriorization of the testicle of scrotal tissue. through a smaller incision as the skin stretches. These improvements in surgical efficiency translate into reduced anesthetic and surgical times, factors well-correlated with reduced risk for surgical-site infec- The risk for inadvertent ligation or tions.12,13 The risk for inadvertent accidental laceration of the urethra during ligation or accidental laceration of the urethra during closure of a pre- closure of a prescrotal castration is scrotal castration is eliminated with eliminated with the scrotal approach. the scrotal approach; in addition, less suture is implanted, resulting in decreased procedural cost.

88 cliniciansbrief.com May 2016 Another benefit of the scrotal approach becomes apparent in the event of incomplete ligation of the spermatic cord resulting Another benefit of in postoperative hemorrhage. the scrotal approach As the incision is only partially closed, postoperative hemorrhage becomes apparent is readily identified and can often in the event of be addressed through the existing surgical site. Postoperative hemor- incomplete ligation rhage in a patient that underwent of the spermatic an alternate castration approach is often more difficult to detect until cord resulting in the scrotum begins to swell. The postoperative authors have not encountered a case of postoperative hemorrhage hemorrhage. in which the spermatic cord retracted into the abdomen and was not retrievable through the original surgical site; this is likely secondary to the comparatively more distal location of spermatic TABLE cord ligation with the scrotal approach. BENEFITS & DRAWBACKS OF A SCROTAL APPROACH FOR ELECTIVE CANINE CASTRATION The major disadvantage of a scrotal approach is the likelihood of a small amount of postoperative Benefits Drawbacks drainage, which many pet owners would find objectionable. Continu- Reduced anesthetic time Short-term postoperative ous drainage of frank blood or the drainage common presence of blood clots suggests Reduced surgical time the need for reassessment. Gentle tissue handling, a vasoconstrictive Reduced costs splash block (eg, 1 part epinephrine [1 mg/mL] to 9 parts 2% lido- Reduced use of suture material caine), and a scrotal wrap can help Decreased incision size minimize this occurrence (Table). Such drainage should cease by the Reduced pain and self-trauma time the patient is discharged (ie, No risk of urethral ligation, laceration, or suturing within a few hours), particularly if patients are hospitalized postoper- Ready identification of postoperative hemorrhage atively. Reduced likelihood of scrotal hematoma formation

Reduced likelihood of seroma formation

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STEP-BY-STEP WHAT YOU WILL NEED h Small-sized, low-powered, electric clippers h Antiseptic scrub STEP 1 h Sterile surgical castration pack Aseptically prepare the surgical –Surgical drapes site by clipping an area around and –4 Huck towels including the scrotum; scrub with –4 towel clamps an appropriate antiseptic. To –Operating room scissors ensure a smooth surface and adequate contact of antiseptic with the –4×4 gauze surgical site, hold the testicles taut 1 –Carmalt or mosquito forceps against the scrotal skin while per- d Surgical site clipped for scrotal –Needle drivers forming the scrub. castration. –Thumb forceps Care should be taken to avoid der- –#10 or #15 surgical blade matitis, or “clipper burn,” while h Sterile gloves clipping scrotal tissue. It is not nec- h 0, 2-0, or 3-0 monofilament essary to completely remove every suture hair; clipping should focus on the h Green tattoo ink and tissue removal of long, dense hairs that adhesive may contaminate the surgical field. It is not necessary When clipping over the scrotum, Optional: grasp the testicles away from the to completely h Clean 3”×3”gauze square and body to pull the skin taut and allow remove every hair; self-adherent bandaging tape adequate contact of scrotal hair h 9:1 mixture of 2% lidocaine and with the clipper blade. clipping should epinephrine (1 mg/mL) focus on the Author Insight removal of long, Use small-sized, low-powered, electric clippers to minimize dense hairs that trauma to the scrotal skin may contaminate during clipping. the surgical field.

d Small, low-powered clippers appropriate for use in clipping scrotal hair (shown with a 22- gauge, 1-inch, over-the-needle, IV catheter for size comparison).

90 cliniciansbrief.com May 2016 STEP 2 Once the scrotum is aseptically draped, gently grasp 1 of the testicles and direct it caudoventrally and away from the body to pull the scrotal skin taut over the testicle. Incise the ventral-most surface of the testicle just lateral to the median raphe. Take care to avoid incising the epi- didymis. An incision approximately 2 one-third of the length of the long axis of the testicle will be required d An incision is made just lateral to the median raphe, directly over to exteriorize the testicle. the first testicle to be removed. Author Insight If 1 testicle lies more cranially than the other, remove the more cranial testicle first. Doing so takes advantage of the greater mobility of the second, more caudal, testicle when moving it cranially toward the initial incision for exteriorization.

STEP 3 Once the initial incision is made, the procedure continues as with any other castration technique. Bluntly (manually) or sharply dissect the spermatic fascia and scrotal ligament until the spermatic cord is iso- lated from all visible connective tissue. Open, modified-open, and closed castration techniques can all be used with the scrotal approach. After ligation of the spermatic cord and confirmation of hemostasis, replace the cord deep within the 3 scrotum. The number and type of d The first spermatic cord is ligated and hemostasis is confirmed. ligatures placed along with suture Note that a closed castration is depicted. size and type are all left to surgeon discretion. Author Insight When manually disrupting the layers of spermatic fascia and scrotal ligament, take care not to pinch the scrotal tissue to avoid unnecessary discomfort, bruising, and subsequent postoperative self-trauma. In large and/or older adult dogs, a combination of sharp and blunt dissection of the spermatic fascia is recommended.

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be taken not to grasp the scrotal STEP 4 skin with thumb forceps while Grasp the second testicle and hold it placing the suture and the knot directly underneath the site of the should be inverted. In general, the initial skin incision. Incise the scro- suture selected for ligation of the tal septum and spermatic fascia to spermatic cord is appropriate for expose the parietal vaginal tunic. closure as described here. The goal Exteriorize and remove the second of suture placement is gentle appo- testicle as described in Step 3. sition of the incision site (not liga- 4 tion of tissue or complete incisional d The second testicle is directed toward At the surgeon’s discretion, the inci- closure) to promote rapid healing, the initial incision prior to incision sion may be partially closed by the serve as a barrier against surgical through the spermatic fascia and placement of 1 interrupted suture in site contamination, and reduce exteriorization. the dartos fascia using absorbable, postoperative self-trauma. monofilament suture. Care should

STEP 5 Author Insight Placement of a vasoconstrictive splash block (consisting of 1 part Gently, manually invert the incision deep within the scrotal area to epinephrine [1 mg/mL] to 9 parts 2% lidocaine) prior to closure serve as an additional barrier to may provide additional analgesia and help minimize any post- environmental contamination and operative drainage. improve cosmesis. Everting of the incision as is often done after scrotal orchiectomy in other species prescrotal region to identify the (eg, cats) is not recommended dog as surgically sterilized. The because of the anatomical position prescrotal region is preferred to of the canine scrotum. ensure visualization of the tattoo (and recognition of the dog as neu- Because of lack of a visible surgical tered) should a future surgeon scar after wound healing, it is attempt a prescrotal or caudal important to place a tattoo in the abdominal approach in suspicion of retained testicles.15 Score the skin with the scalpel blade, place a Author Insight small amount of tattoo ink within 5 the scored area, pinch the skin Do not attempt to fully close d The incision site is inverted and closed, and apply a drop of tissue the dartos fascia, intradermal, invisible after completion of the glue to prevent the ink from being procedure. Note the application of a and/or cutaneous layers of licked or transferred into the envi- tattoo in the prescrotal region the incision with sutures, as ronment. permanently identifying the dog as this can lead to discomfort, surgically sterilized. seroma formation, self- trauma, and postoperative complications.14

92 cliniciansbrief.com May 2016 ture and prevent environmental STEP 6 contamination and self-trauma. A small amount of serosanguinous fluid draining from the surgical The scrotal wrap should not be left site is expected for the first few in place for more than a few hours hours after the procedure. In large and, if still in place, must be dogs, or those with a pendulous removed prior to patient discharge scrotum, place a small piece of to prevent accidental ingestion, clean gauze directly over the surgi- pressure necrosis and delayed 6 cal site and wrap it securely with wound healing, or caregiver injury d A scrotal wrap has been placed to self-adhesive bandage material (eg, while attempting to remove the apply compression, collect any 3M VetRap, 3M.com). This scrotal wrap. As with any castration postoperative discharge, and protect wrap will apply compression to approach, standard postoperative the surgical site. reduce any drainage and allow for instructions (eg, observing a the collection, quantification, and period of exercise restriction, regu- assessment of any drainage that lar monitoring of the surgical site) References on page 107. does occur. Additionally, it can pro- are recommended. n vide hemostasis of scrotal vascula-