By -Dr. Amarnath Muthukrishnan1 and Rajesh Kumar K2
1. Senior Veterinary Consultant and Director of Amulya Pets Speciality Clinic, Salem – 636004
2. Final year student BVSc & AH, Veterinary College & Research Institute, Orathanadu, Thanjavur – 614625
ABSTRACT
A 5 year old intact male Labrador retriever was brought to a (Amulya Pets Speciality Clinic) clinic at Salem, with the complaint of swollen left ear flap for more than a one month. Physical examination revealed soft fluctuating fluid filled swelling which extend till the base of the ear, partially blocking the ear canal opening. Based on these clinical findings the tentative diagnosis was made as “Full Ear Othaematoma”. Thus, surgical correction was recommended and fixed after pet parent’s consent. Instead of conventional surgical correction of incising, draining and suturing, we opted for a novel technique using surgical carbon dioxide (CO2) laser. The CO2 laser beam has been described in human medicine for cosmetic surgeries, CO2 laser works on the principle of sealing the local nerve endings and lymphatics, resulting in less edema and pain. Using this technique here demonstrate how a painful condition like Othaematoma can be corrected maintaining all the cosmetic and aesthetic value of the ear pinna. Thus, we would like to demonstrate and propose the use of the CO2 laser in a way that it offers several potential advantages to the veterinary practitioner in day to day practice.
INTRODUCTION
Hematoma is localized pool of blood that is confined within an organ or tissue. Othaematoma (Aural haematoma) are the most common traumatic injury sequelae of the ear pinna in dogs and rarely in cats. It is attributed as the most common physical injury of the pinna with irritation from ear mites or ticks, fly bite, otodectic mange and otitis as indicating causes (Fossum, T.W., Cheryl, S.H., Johnson, A.L. Schulz, K.S., Seim, H.B., Willard, M.D., Bahr, A. and Carroll, G.L. 2007. Aural hematomas and Traumatic lesions of the pinna. In Textbook of Small Animal Surgery 3rd Edition: Eds., Theresa Welch Fossum: Elsevier science, Morsby Inc Publishers, pp: 307-312). They are mostly evident on concave surface of the Pinna. The swelling may involve the entire ear flap or it may be confined to a part of ear pinna. Whenever pets vigorously share their heads or scratch their ears, trauma to the ears causes the blood vessels and capillaries in the ear pinna to rupture thereby causing a pool of blood to
accumulate between the layers of the pinna (Henderson, R.A. and Horne, R. 2003. Pinna. In: Slatter Douglas, Textbook of small animal surgery. 3rd ed. Philadelphia, Saunders W.B. Publishers, pp-1737-1741). Incidence of Othaematoma is common in pendulous ear dogs like Labrador, Cocker spaniel and Basset hound but is also seen in the upright ear breeds like German shepherd and some breed of Spitz.
ANATOMY & PATHOPHYSIOLOGY
Before making a choice of repair of Othaematoma, it is important to understand the anatomy of the pinna. The ear flap is comprised of two layers of skin covering a layer of cartilage. The cartilage gives the ear flap its shape. The pinna receives the blood supply from branches of the great auricular arteries, and is returned through the auricular veins. The main vessels are located along the convex surface of the ear, and small branches pass through the cartilage to supply the concave surface. Basically, a network of vessels run parallel to the long axis of the ear. Blood vessels go from side-to-side by passing through the cartilage. Othaematoma usually result due to irritation to the part of the ear, the dog reacts to the irritant by scratching the ear or shaking its head. Excessive shaking or scratching can in rupture of the thin blood vessels and capillaries resulting in bleeding thereby accumulation of pool of blood between the cortical and skin especially on concave surface of the pinna. Thus, the space between the cartilage and pinna skin fills up with blood tinged serosanguineous fluid forming “Othaematoma”. This bleeding continues until the pressure created by the pooling blood equalizes with the pressure from the arteries themselves. Recommendation is to drain Othaematoma as soon as possible. If left untreated, will lead to fibrin formation leading to fibrosis on the walls of Othaematoma, further causes corrugation and thickening of the walls potentially assuming a curled-up conformation often called “Cauliflower Ear” (Medleau, L. and Hnilica, K.A.2006. Small animal dermatology: A color atlas and therapeutic guide. 2nd ed. Philadelphia, Saunders W.B. Publishers). Several techniques have been proposed for draining and eliminating Othaematoma. However, the choice of the appropriate technique depends on how long the Othaematoma has been present. Recurrence of Othaematoma is common if the underlying aetiology is not addressed, so it is very crucial to do a thorough otoscopic examination for presence of foreign body inside the ear, mites or tick infestation, any incidence of growth along the middle ear or chronic internal ear infections, damage to tympanic membrane, atopic dermatitis etc. Endocrine disturbances like hypothyroidism and hyperadrenocorticism should also be investigated and treated for expected recovery. Having understood the underlying aetiology and counselled the pet parents with pros and cons of the surgical correction, the surgery is taken up under appropriate anaesthetic protocol. The purpose of surgery is to remove the blood clots and to pressure align the layers of the pinna together to eliminate dead space, prevent recurrence of the Othaematoma and to conserve the aesthetic appearance of affected ear(s).
MATERIAL AND METHODS
Patient pre anaesthetised using xylazine @ 0.5mg per kg and butorphanol @ 0.1mg per kg, induction of anaesthesia was obtained using Propofol @ 4mg per kg, while anaesthesia maintenance was done under inhalant Isoflurane @ 2L/min. Surgical CO2 laser was programmed with continuous mode of 10 watts power for incision and pulse mode of 12 watts power for welding procedures.
SURGICAL PROCEDURE
Anesthetised patient was re-evaluated for baseline etiology as well as extent of Othaematoma. Surgical site was prepared using sterile povidone iodine, as surgical spirit could lead to accident due to inflammable nature during CO2 laser usage (Mona Boord, DVM, DACVD, Laser in Dermatology, Clin Tech Small Anim Pract. 2006 Aug;21(3):145-9). Ear canal was plugged with sterile gauze ear pinna was surgically prepared on both concave and convex surface using chlorhexidine and sterile saline, and draped for aseptic surgery. For additional field block ligonocaine 2% was infiltrated circumferentially around Othaematoma to obtain local blocking of nerve impulse. However, care should be taken to avoid the infiltration into the surgical site (DS Krupa Shankar, M Chakravarthi, and Rachana Shilpakar, Carbon Dioxide Laser Guidelines, J Cutan Aesthet Surg. 2009 Jul-Dec; 2(2): 72–80).
A linear incision along the length of the pinna was made in paramedian region using continuous mode high voltage CO2 laser beam at 10 watts of power and a 0.8 mm ceramic tip (Teresa L. Dye, DVM, H. Douglas Teague, DVM, MS, Diplomate ACVS, Donald A. Ostwald Jr., DVM, Diplomate ABVP, Steven D. Ferreira, DVM, Evaluation of a Technique Using the Carbon Dioxide Laser for the Treatment of Aural Hematomas J Am Anim Hosp Assoc 2002;38:385–390), on the concave surface of the ear pinna. This led to copious draining of the accumulated serosanguinous fluid. Also, multiple circular incision about 2.0 – 2.5 mm were made on either side of the linear incision spanning the surface area of the extent of Othaematoma. This provides the required drains, helps in better drainage as well as prevents the recurrence of Othaematoma.
After draining the fluid, fibrin clots and inflammatory debris was scraped and the cavity was emptied. Then the cavity was then irrigated with povidone iodine solution which also initiate the granulation tissue formation within the cavity.
Subsequent to draining and lavage, healing is initiated through second intention by welding. The edges of all the circular incisions were welded using CO2 laser but at pulsated mode at 12 watts of power. Tissue welding with the CO2 laser has been used for closure of skin and visceral incisions and anastomosis of tendons, vessels, and nerves (Bass LS, Moazami N, Pocsidio J, et al. Changes in type I collagen following laser welding. Lasers Surg Med 1992;12:500–5). Tissue welding occurs when the energy from the laser causes lysis of the collagen bonds within the tissue. This provides better healing and very less nociception by sealing the terminal axons and vasculature.
POST SURGICAL MANAGEMNET
After thorough client education on medical management. Patient was treated for prevention of secondary bacterial infection, parenterally using a course of antibiotic ceftriaxone 500mg as intramuscular injection (I/M) SID for 5 days, also was put on mild dose of corticosteroids, Dexamethasone @ 0.2mg per kg and pain management was done using Meloxicam @ 0.2mg per kg also parenterally as intramuscular injection. A conical pressure bandage was removed on second day and healing was enhanced by application of collagen hydrogel-based ointment along with Mupirocin 2% w/w antibiotic ointment.
RESULTS AND DISCUSSION
Although the learning curve and cost of equipment of CO2 laser has precluded its widespread usage in veterinary medicine, the following advantages promote its application worthy. The CO2 laser beam is absorbed by intracellular water, limiting the depth of tissue damage. Almost 90% of the laser energy is absorbed within a width of <0.01 mm. (Crane SW. Carbon dioxide lasers in veterinary surgery. In: Using the CO2 laser in the veterinary practice training manual. Bothel, Washington: Luxaz Accuvet, publication division). This produces a zone of devitalization larger than that created by a scalpel blade but much smaller than that caused by electrocautery. The tissue trauma by 0.1-0.2 mm from the incision site tissues get is negligible compared to any other surgical correction techniques of Othaematoma. Almost negligible tissue scarring promotes faster granulation tissue formation. Decreased haemorrhage due to principle of CO2 laser which cuts and seals simultaneously the micro capillaries (0.5-0.6 mm wide) of surgical site (Joanna Paczuska, Zdzisław Kiełbowicz, Marcin Nowak, Agnieszka Antończyk, Rafał Ciaputa, and Jakub Nicpoń, The carbon dioxide laser: an alternative surgery technique for the treatment of common cutaneous tumors in dogs, Acta Vet Scand. 2014; 56(1): 1). Significantly decreased operative time (15-30 minutes) due to minimal handling of tissues, less haemorrhage, no suturing helps in cutting down the anaesthetic exposure too. It also seals the lymphatic vessels thereby preventing edema and fluid accumulation. Its seals the terminal nerve endings axons (Adrienne E. Dubin and Ardem Patapoutian, Nociceptors: the sensors of the pain pathway J Clin Invest. 2010 Nov 1; 120(11): 3760–3772) there by inducing nociceptive action too, thus postoperative handling of patient becomes very comfortable both for pet parents as well as attending veterinarian.
CONCLUSION
The use of the CO2 laser offers several potential advantages to the veterinary surgeon such as, decreased tissue trauma, decreased scarring, decreased haemorrhage, decreased operative time, decreased postoperative swelling and edema, decreased postoperative pain, and induced sterility of the surgical field. Owing to the numerous advantages, we therefore strongly propose and advocate usage of “CO2 laser” for surgical correction of Othaematoma and other similar procedures with aesthetic significance. However, there is a need for large number of such surgical samples to propose a standard operating protocol for surgical correction of Othaematoma /Aural Hematoma in the field of veterinary sciences.
R
EFFERENCES
1. Fossum, T.W., Cheryl, S.H., Johnson, A.L. Schulz, K.S., Seim, H.B., Willard, M.D., Bahr, A. and Carroll, G.L. 2007. Aural hematomas and Traumatic lesions of the pinna. In Textbook of Small Animal Surgery 3rd Edition: Eds., Theresa Welch Fossum: Elsevier science, Morsby Inc Publishers, pp: 307-312.
2. Henderson, R.A. and Horne, R. 2003. Pinna. In Slatter Douglas, Textbook of small animal surgery. 3rd ed. Philadelphia, Saunders W.B. Publishers, pp-1737-1741
3. Medleau, L. and Hnilica, K.A. 2006. Small animal dermatology. A color atlas and therapeutic guide. 2nd ed. Philadelphia, Saunders W.B. Publishers
4. Mona Boord, DVM, DACVD, Laser in Dermatology, Clin Tech Small Anim Pract. 2006 Aug;21(3):145-9
5. DS Krupa Shankar, M Chakravarthi, and Rachana Shilpakar, Carbon Dioxide Laser Guidelines, J Cuta Aesthet Surg. 2009 Jul-Dec; 2(2): 72–80.
6. Teresa L. Dye, DVM, H. Douglas Teague, DVM, MS, Diplomate ACVS, Donald A. Ostwald Jr., DVM, Diplomate ABVP, Steven D. Ferreira, DVM, Evaluation of a Technique Using the Carbon Dioxide Laser for the Treatment of Aural Hematomas J Am Anim Hosp Assoc 2002;38:385–390.
7. Bass LS, Moazami N, Pocsidio J, et al. Changes in type I collagen following laser welding. Lasers Surg Med 1992;12:500–5.
8. Crane SW. Carbon dioxide lasers in veterinary surgery. In: Using the CO2 laser in the veterinary practice training manual. Bothel, Washington: Luxar Accuvet, publication division
9. Joanna Paczuska, Zdzisław Kiełbowicz, Marcin Nowak, Agnieszka Antończyk, Rafał Ciaputa, and Jakub Nicpoń, The carbon dioxide laser: an alternative surgery technique for the treatment of common cutaneous tumors in dogs, Acta Vet Scand. 2014; 56(1):1
10. Adrienne E. Dubin and Ardem Patapoutian, Nociceptors: the sensors of the pain pathway J Clin Invest. 2010 Nov 1; 120(11): 3760–3772
