CASE REPORT Guttural Pouch Hemorrhage Associated with Lesions of the Maxillary Artery in Two Horses

K.M. SMITH AND S.M. BARBER Wetaskiwin Veterinary Hospital, 4808-40th Avenue, Wetaskiwin, Alberta 79A OA2 (Smith) and Department ofAnesthesia, Radiology and Surgery, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan 57N 0 WO (Barber)

Summary roughbred hongre et age de deux ans, poches gutturales, occlusion arterielle, A two year old Thoroughbred geld- dont la poche gutturale gauche sai- pneumatique, cheval. ing, presented with guttural pouch gnait abondamment, avait subi la liga- hemorrhage, had the internal and ture des carotides interne et externe external carotid arteries ligated. Gut- correspondantes. Un examen endo- Introduction tural pouch mycosis was detected on scopique de cette poche gutturale Ulceration of vessels on the wall of endoscopic examination. After one permit d'y deceler une infection myco- the guttural pouch commonly occurs month of topical antifungal therapy, sique. En depit d'un traitement anti- with guttural pouch mycosis, and is the horse was returned and euthanized mycosique topique d'une duree d'un characterized by acute, often fatal, because of recurrent epistaxis. A bac- mois, il fallut hospitaliser de nouveau epistaxis (1-6). Approximately 50% of terial infection of the guttural pouch le cheval, a cause d'une epistaxis recur- affected horses die offatal hemorrhage with associated ulceration and hemor- rente, et son proprietaire en demanda (7). Usually several bouts of epistaxis rhage from the maxillary artery was l'enthanasie. La necropsie de l'animal occur before a fatal episode, but there found at necropsy. permit de decouvrir une infection bac- is no predictable pattern (1). The slow A two year old grade gelding had terienne ulcereuse de cette poche gut- response of mycotic lesions to local ulceration and hemorrhage from the turale, qui s'accompagnait d'une and parenteral therapy prolongs the . Utilizing hemorragie de l'artere maxillaire risk of hemorrhage and encourages balloon-tipped and arterial gauche. surgeons to intervene to occlude blood ligation, hemestasis was achieved in La carotide externe gauche d'un flow to the guttural pouch. the and the cheval croise, hongre et age de deux Mycotic ulcerations most fre- external carotid artery and its ans, affichait une ulceration hemorra- quently involve the internal carotid branches. Mycotic ulceration of the gique. A l'aide de catheters pneuma- artery as it courses over the wall of the internal carotid artery was detected tiques et de ligatures, les auteurs reus- guttural pouch (1). This blood vessel is endoscopically and treated with local sirent 'a effectuer l'hemostase de la not an end artery because blood may antifungal therapy for one month. carotide interne, ainsi que celle de la enter it from the common carotid Thirty-three days postoperatively the carotide externe et de ses branches. Un artery or the circle of Willis. Complete horse returned, bleeding from a lesion examen endoscopique revela une hemostasis can only be achieved if the in the maxillary artery. The rationale ulceration mycosique de la carotide vessel is occluded on either side of the for surgical intervention to prevent interne gauche qu'on traita avec un vascular lesion (7). Mycotic invasion epistaxis associated with guttural antimycosique topique, pendant un of the internal carotid artery com- pouch mycosis and possible etiologies mois. Trente-trios jours apres l'inter- monly occurs where the artery enters for postsurgical epistaxis are dis- vention, il fallut hospitaliser de nou- the foramen lacerum just before join- cussed. veau l'animal, parce que son artere ing the circle of Willis. The close prox- maxillaire gauche affichait une lesion imity of the mycotic lesion to the skull Key words: Epistaxis, guttural pouch h.emorragique. and the limited exposure, makes surgi- mycosis, arterial occlusion, balloon Les auteurs commentent les raisons cal placement of a distal vascular liga- catheter, horse. que justifient une intervention chirur- ture difficult and sometimes impossi- gicale destinee a enrayer l'epistaxis qui ble (8). In addition, uncontrollable Re'sume accompagne une mycose des poches hemorrhage and cranial nerve damage Hemorragie des poches gutturales gutturales, ainsi que les causes possi- secondary to surgical invasion to qu'accompagnaient des lesions de l'ar- bles de l'epistaxis post-chirurgicale. insert a distal ligature has been tire maxillaire de deux chevaux reported (3,7,9). Les auteurs rapportent qu'un Tho- Mots cles: epistaxis, mycose des The use of intravascular balloon-

Can Vet J 1984; 25: 239-242. 239 tipped catheters is the treatment of from the common carotid. All liga- tural pouch. The site of hemorrhage choice in preventing hemorrhage from tures were double. The surgical site was not determined specifically the internal carotid artery associated was lavaged with crystalline penicillin because endoscopic examination of with guttural pouch mycosis (10,11). G-saline mixture and closed. the guttural pouch would risk dislodg- Such catheters allow for occlusion of Following surgery, a left-sided ing the clot and producing fatal otherwise inaccessible vasculature dis- Horner's syndrome and blindness of hemorrhage. tal to the site of the lesion while min- the left eye were present. Endoscopic Using a surgical approach identical imizing the risk of injury to cranial examination five days postoperatively to that in case 1, the internal, external nerves in the wall of the guttural showed a mycotic-appearing lesion and common carotids, the occipital pouch. near the articulation of the stylohyoid artery and the linguofacial trunk of Mycotic lesions of the internal bone with the skull. The left guttural external carotid were identified. No. I carotid artery are usually the source of pouch was catheterized and flushed Polyester' suture was used to doubly epistaxis, but fatal hemorrhage due to daily with griseofulvin for two weeks, ligate the above-mentioned vessels, mycotic ulceration of the maxillary after which the horse was discharged. according to the pattern depicted in artery has been reported (12). Reports The horse was readmitted 27 days Figure la and I b. of surgical treatment of maxillary later following the second bout of With the internal carotid artery ele- artery lesions are not present. In this postoperative epistaxis. Left-sided vated and occluded by two umbilical report, two cases of guttural pouch Horner's syndrome and blindness tape traction sutures, a small longitud- mycosis associated with hemorrhage were apparent and with additional inal incision was made in the artery from the maxillary artery are des- epistaxis, the owner requested immediately rostral to its ligation site. cribed, along with their treatment by euthanasia. A balloon-tipped polyvinyl catheter multiple arterial ligations and/or was introduced through the incision balloon-tipped catheters. The diag- Case 2 and advanced rostally a distance of nostic challenge associated with guttu- A weak, depressed and anemic 13 cm, as previously recommended ral pouch hemorrhage and the difficul- (PCV 18%) two year old grade gelding (10). A predetermined volume of ties encountered in its surgical was referred for investigation of saline was flushed into the catheter management is emphasized. intermittent epistaxis of two days which was clamped with a hemostat duration. A lesion of the external and ligated. Excess tubing was Case I carotid artery was suspected based on removed and the catheter was further A two year old Thoroughbred geld- radiographically increased soft tissue secured in position according to the ing was presented following two days densities in the cranioventral aspect of procedures outlined previously (10). ofsporadic bilateral epistaxis. Hemor- the guttural pouch and endoscopic A catheter was inserted into the rhage continued for five days after proof of hemorrhage from the left gut- external carotid artery approximately examination, and a large blood clot was seen hanging from the left naso- pharyngeal orifice by the endoscopist. The decreasing hemogram and danger of fatal hemorrhage were considered indications to surgically occlude blood flow to the left guttural pouch. Anesthesia was induced with xyla- zine and thiamylal and maintained with halothane. The left parotid area was prepared for aseptic surgery and a 20 cm curvilinear incision was made 2 cm cranial to the wing of the atlas. Using blunt dissection, the parotid 17' was reflected cranially, and the common carotid artery identi- fied. With further dissection distally the occipital artery and internal and external carotid arteries could be iden- tified. Each vessel was separated from surrounding connective tissue and retracted with umbilical tape. The internal carotid artery was ligated at its origin, and distally, 2 cm ventral to the base of the skull. The external FIGURE la. Diagramatic representation of the location of the guttural pouch, internal and external carotid artery was ligated at its origin carotid arteries, with respect to the skull and .

'Ti.Cron, Davis & Geck, Cyanamid Canada Inc., Montreal, Quebec.

240 rough presurgical endoscopic exami- nation. The opportunity to visualize the origin of the hemorrhage and the nature and extent of the lesion, out- weighs the risk of inducing further hemorrhage through dislodgement of a blood clot in the nasopharyngeal ori- fice. Although preoperative endo- scopic examination of the guttural pouch was not attempted in the above two cases, retrospective consideration would suggest that it should have been. Although the initial site of hemor- rhage was unknown in case 1, in case 2 it could be accurately traced to a mycotic type lesion involving the internal carotid artery. The postsurgi- cal hemorrhage in both cases was traced to defects in the maxillary artery, but in neither was there evi- dence of mycotic involvement. The etiology of postsurgical hemorrhage from the maxillary arteries in these horses remains unknown. The most likely explanation for the postopera- tive hemorrhage in case I would be a chronic bacterial infection leading to erosion and ulceration of the maxil- lary artery. Chronic bacterial infection FIGURE lb. Diagramatic representation of the location of the internal carotid artery and branches of has been implicated in causing ulcera- the external carotid artery in relation to the guttural pouch and the sites of ligation used in case 2. tion of the internal carotid artery (13) Common carotid artery (I), external carotid artery (2), internal carotid artery (3), occipital artery (4), linguofacial artery (5), maxillary artery (6), caudal auricular artery (7), superficial temporal artery and postmortem examination would (8), external ophthalmic artery (9), ligature W. tend to support such an etiology in this case. Other, less likely possibilities include aberrent parasitic migration (7) and endarteritis and rupture due to I cm rostral to its origin using the returned following acute epistaxis. mechanical irritation of the balloon- same technique. It was advanced Endoscopically a blood clot was pres- tipped catheter (10). beyond the origin ofthe ligated linguo- ent in the left nasopharyngeal orifice, The external carotid artery and its facial trunk and blindly positioned in the mycotic lesion was gone and the major branch, the maxillary artery, what was believed to be the maxillary internal carotid artery appeared large are not end arteries. The potential artery. A negative suction drain was and nonpulsating. A thrombus was exists for retrograde blood flow from placed in the incision prior to closure. seen protruding from the lateral wall the circle of Willis, by way of the The horse was immediately transfused of the lateral compartment and the common artery of the corpus callo- with 4.5 L of cross-matched blood. surrounding mucosa appeared pale sum, the rostral meningeal artery, the Penicillin and phenylbutazone were and torn. A diagnosis of hemorrhage external ethmoidal artery and the given for five days and the hemogram and thrombosis ofthe maxillary artery external ophthalmic artery (14). Hem- was monitored. Endoscopic examina- was made. orrhage due to retrograde bleeding tion five days later showed a mycotic- The horse was discharged without from the maxillary artery was con- like plaque overlying the internal treatment. Four months later there firmed on postmortem examination in carotid artery, from which a large had been no recurrence of epistaxis, case I and strongly suspected in case 2. hematoma was seen to protrude. A #10 the guttural pouch endoscopically This emphasizes the importance of French polyethylene catheter, sutured appeared normal and there was no ligating the vessel both proximal and to the nostril, was used to flush the cranial nerve dysfunction or blindness. distal to the site of the lesion. How- guttural pouch twice daily with 60 mL ever, the distal vasculature of the of 10% thiabendazole suspension. Discussion external carotid artery is surgically The horse was discharged on day 12 Guttural pouch hemorrhage may inaccessible and has several different with instructions to continue flushing originate from lesions in the internal terminal branches capable of hemor- the pouch for one month. carotid or maxillary arteries. This rhage. It is impossible to definitely Three weeks later the horse was emphasizes the importance of a tho- localize the balloon in a specific

241 branch without benefit of intraopera- Occlusion of the maxillary artery is 8. FREEMAN DE. Diagnosis and treatment of tive fluoroscopy and it is impossible to indicated when a lesion is present that diseases of the guttural pouch (Part 11). occlude all possible branches which may cause fatal hemorrhage. Compend Contin Educ Pract Vet 1980; 2: might be hemorrhaging. Catheteriza- S25-S31. 9. JOHNSON JH, MERRIAM JG, ATTLEBERGER M. tion of the maxillary artery may be of A case of guttural pouch mycosis caused by limited value unless a specific lesion is Aspergillus nidulans. Vet Med Small Anim identified and the vessel can be References Clin 1973; 68: 771-774. occluded proximal and distal to it. 1. COOK WR. The clinical features of guttural 10. FREEMAN DE, DONAWICK WJ. Occlusion of Extensive unilateral catheterization pouch mycosis in the horce. Vet Rec 1968; internal carotid artery in the horse by means and ligation ofthe major vessels of the 83: 336-345. of a balloon-tipped catheter: Clinical use of equine head can be performed with 2. COOK WR, CAMPBELL RSF, DAWSON C. The a method to prevent epistaxis caused by minimal risk. This supports canine pathology and etiology of guttural pouch guttural pouch mycosis. J Am Vet Med research which demonstrates that mycosis in the horse. Vet Rec 1968; 83: Assoc 1980; 176: 236-240. simultaneous bilateral ligation of both 422-428. 11. FREEMAN DE, DONAWICK WJ. Occlusion of 3. McILWRAITH CW. Surgical treatment ofacute internal carotid artery in the horse by means common carotids and vertebral arter- epistaxis associated with guttural pouch of a balloon-tipped catheter: Evaluation of ies is compatible with life (15). The mycosis. Vet Med Small Anim Clin 1978; a method designed to prevent epistaxis postsurgical blindness seen in case 1 is 73: 67-69. caused by guttural pouch mycosis. J Am Vet a cause for concern. The central retinal 4. LINGARD DR, GOSSER HS, MONFORT TN. Acute Med Assoc 1980; 176: 232-235. artery arises from the external oph- epistaxis associated with guttural pouch 12. BJORKLUND NE, PALSSON G. Guttural pouch thalmic artery, which is a branch ofthe mycosis in two horses. J Am Vet Med Assoc mycosis in the horse. A survey of 7 cases: A maxillary artery (14). The possibility 1974; 164: 1038-1040. case report. Nord Vet Med 1970; 22: 65-74. of producing blindness from ischemic 5. PETERSON FB, HARMONY K, DODD DC. Clinico- 13. BOUCHER WB, ELLIOTGA, SCHMUCKER B. Epis- retinal damage, should be considered pathologic conference. J Am Vet Med taxis due to rupture of an aneurysm in a before occluding blood flow through Assoc 1970; 157: 220-228. horse. J Am Vet Med Assoc 1964; 145: 6. FREEMAN DE. Diagnosis and treatment of 1004-1006. the external carotid artery. The lack of diseases of the guttural pouch (Part 1). 14. GETTY R. Sisson & Grossman's The anatomy postoperative blindness in case 2 sug- Compend Contin Educ Pract Vet 1980; 2: of the domestic animal, 5th edition. Phila- gests that because of normal anatomi- S3-S I 1. delphia: WB Saunders Co., 1965: 576-583. cal variation or the presence of collat- 7. OWEN R AP R. Epistaxis prevented by ligation 15. BUNCE DFM. Survival of dogs following sec- eral circulation blindness may occur in of the internal carotid artery in the guttural tion of carotid and vertebral arteries. Proc some cases but cannot be predicted. pouch. Equine Vet J 1974; 6: 143-149. Soc Exp Biol Med 1960; 103: 581-585.

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