Saturday, August 16, 2014

Scrotal Hematoma in Dogs After Castration: Why does it happen and how to prevent it.

Scrotal hematoma, the accumulation of blood in the scrotal sac, is a common postoperative complication of castration in dogs. (Fig. 1) 
Fig. 1: Scrotal hematoma that developed after castration in this golden retriever
Postoperative bleeding from one or both testicular arteries or veins is the most likely cause. Bleeding from these vessels can also accumulate in the abdominal cavity and be unrecognized until the dog becomes hypovolemic and develops shock. Bleeding from subcutaneous tissues could also result in a scrotal hematoma but is less likely, particularly in cases where bleeding is severe and the scrotal hematoma is large.

Etiology
Insecure ligatures are probably the cause of bleeding from testicular vessels. Ligature failure during castration may be due to a number of technical problems, such as loose ligature, improper suture material, or ligature slippage. Improper location of the suture ligature can also predispose to failure. If the spermatic cord is not adequately exteriorized the ligatures will be placed too close to the testicle. (Fig. 2) 
Fig. 2: The red dotted line indicates ligation of the spermatic cord too close to the testicle (T)
The ligatures in the figure are placed in the proper location.
(Modified from: Boothe, HW. Surgery of the testicles and scrotum. Saunders Manual of Small Animal Practice, Birchard and Sherding editors,  Figure 87-1, Elesevier, 2006, pg. 970.)
This causes excessive tissue to be incorporated in the ligatures. Insufficient stripping of the adipose tissue from the cord also predisposes the ligature to slippage.

Treatment
Scrotal hematomas can be managed medically with compresses (ice packs for the first 24 hours postoperatively, followed by warm compresses), Elizabethan collar, restricted exercise, analgesics such as NSAIDS, and antibiotics. In severe cases or those not responding to medical therapy, scrotal ablation is necessary to remove the entire scrotum and its contents.

Prevention
To prevent scrotal hematoma when performing castration, adhere to the following technical principles:
- After incising over the testicle and exposing it, break down the gubernaculum testis and place traction on the testicle to allow several centimeters of the spermatic cord to be exposed. (Fig. 3)
Fig. 3: Proper exposure and clamping of the spermatic cord during routine canine castration.
- Carefully and thoroughly strip the adipose tissue from the spermatic cord with a moistened surgical sponge.
- Triple clamp the cord with Carmalt clamps, cut between the 2 clamps closest to the testicle and perform routine ligatures with Monocryl or PDS suture (transfixing and full ligatures). The full ligature is placed in the crush area of the most proximal clamp after it is removed, the transfixing ligature is placed just distal to the full ligature. (Fig. 4)
Fig. 4: Proper ligature technique in a closed canine castration. (T=testicle)
(Modified from: Boothe, HW. Surgery of the testicles and scrotum. Saunders Manual of Small Animal Practice, Birchard and Sherding editors, Elesevier, 2006, Figure 87-1, pg. 970.)
- Check the vascular stump for bleeding prior to replacing it into the incision. Repeat the same procedure on the opposite side.  

I prefer closed castration, even on large dogs, because it allows excision of the testicular tunics along with the testicle. (Fig. 5)
Fig. 5: Closed castration allows removal of the parietal vaginal tunic with the testicle
Close the subcutaneous tissue routinely (3-0 or 4-0 absorbable suture in a simple continuous pattern). Although skin sutures can be used on the skin incision, I prefer do an intradermal closure in lieu of skin sutures. Fewer complications occur with an intradermal closure of castration incisions. In an unpublished study performed at Ohio State several years ago, dogs with intradermal skin closure had fewer incisional problems and even fewer scrotal hematomas postoperatively. Less self-trauma to the incision and scrotum were thought to be the reason for this finding.

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3 comments:

  1. Acknowledging that this is a pretty old post at this point, thanks for your helpful discussion Dr Birchard, and your many years of instruction from which so many of us have benefited. With regard to the surgery discussed here, I curious about the comment that you prefer the closed castration technique “because it allows excision of the testicular tunics along with the testicle.” I’ve heard/read similar sentiments in the past with the same curiosity. When I started doing these surgeries, back in the early ‘90s, I had occasion to talk with another practitioner who’d been out of school for several years longer than I, and the question of open vs closed came up. He said that he preferred the former, because “I like to be able to see what I’m ligating.” That observation made a lot of sense to me and, for the most part, that’s how of done them since, numbering maybe 10,000 (or probably more) by now. (In addition to full service clinics, I’ve spent many years at shelters and other high volume spay/neuter clinics.) After all these years I could certainly be mistaken about this, but, to my knowledge, I’ve never had a scrotal hematoma. (I have done a few ablations though!) The other advantage I’ve found with the open technique is that, in very many (maybe most) cases, I can simply instrument tie the vessels/vas exactly as is done by me and many other veterinary surgeons with tom cats, greatly reducing surgery times. (That said, the truly big guys I still ligate.) Used selectively as I have, I’ve not had issues with this technique either. (If it’s useful in a cat, why not in a dog?) Anyway, just thought I’d ask. Thanks again!

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  2. Acknowledging that this is a pretty old post at this point, thanks for your helpful discussion Dr Birchard, and your many years of instruction from which so many of us have benefited. With regard to the surgery discussed here, I curious about the comment that you prefer the closed castration technique “because it allows excision of the testicular tunics along with the testicle.” I’ve heard/read similar sentiments in the past with the same curiosity. When I started doing these surgeries, back in the early ‘90s, I had occasion to talk with another practitioner who’d been out of school for several years longer than I, and the question of open vs closed came up. He said that he preferred the former, because “I like to be able to see what I’m ligating.” That observation made a lot of sense to me and, for the most part, that’s how of done them since, numbering maybe 10,000 (or probably more) by now. (In addition to full service clinics, I’ve spent many years at shelters and other high volume spay/neuter clinics.) After all these years I could certainly be mistaken about this, but, to my knowledge, I’ve never had a scrotal hematoma. (I have done a few ablations though!) The other advantage I’ve found with the open technique is that, in very many (maybe most) cases, I can simply instrument tie the vessels/vas exactly as is done by me and many other veterinary surgeons with tom cats, greatly reducing surgery times. (That said, the truly big guys I still ligate.) Used selectively as I have, I’ve not had issues with this technique either. (If it’s useful in a cat, why not in a dog?) Anyway, just thought I’d ask. Thanks again!

    ReplyDelete
    Replies
    1. Thank you for your comments Dr. Scheule. I appreciate your observations and thoughts. Like many surgeries, the choice of technique is based on sound principles and surgeon preference. Either closed or open castration is certainly acceptable and consistent with current standards of care. My choice of the closed technique is due to seeing problems with infection secondary to the tunics left in the scrotum. The few cases I've seen of this problem has biased me toward removing the tunics with the testicle and vessels. But, I have not seen either technique have a higher incidence of scrotal hematoma. I probably should make that more clear in the article. Thanks again for your insight and allowing the readers to benefit from your broad experience. SJB

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