Coil embolization of a palatine artery pseudoaneurysm in a gelding

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Text of Coil embolization of a palatine artery pseudoaneurysm in a gelding

  • 1.Coil Embolization of a Palatine Artery Pseudoaneurysm in a Gelding Nathaniel R. McClellan1 , DVM, Margaret C. Mudge1 , VMD, Diplomate ACVS, ACVECC, Brian A. Scansen1 , DVM, MS, Diplomate ACVIM, Stephen S. Jung2 , MD, FACR, and Duncan Russell3 , BVMS (Hons), Diplomate ACVP 1 Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, Ohio ,2 Radiology Incorporated and Mount Carmel Health Care, The Ohio State University, Columbus, Ohio and 3 Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio Corresponding Author Margaret C. Mudge, VMD, Diplomate ACVS, ACVECC, Department of Veterinary Clinical Sciences, The Ohio State University, 601 Vernon L. Tharp Street, Columbus, OH 43210. Email: margaret.mudge@cvm.osu.edu Submitted November 2011 Accepted June 2012 DOI:10.1111/j.1532-950X.2014.12174.x Objective: To describe successful transarterial coil embolization of a palatine artery pseudoaneurysm that extended into the caudal maxillary sinus of a gelding. Study Design: Clinical report. Animal: A 24yearold Morgan gelding with rightsided epistaxis. Methods: The right maxillary sinus was imaged by radiography, computed tomography, and sinoscopy. Angiography was performed to locate the source of bleeding, and transarterial coil embolization of a right palatine artery pseudoaneurysm was performed. Results: There was some mucoid nasal discharge and an intermittent cough postoperatively. No epistaxis was seen after embolization. There was moderate swelling of the surgical incision over the midcervical common carotid artery. The horse was discharged from the hospital 4 days after surgery, and had been doing well, with no signs of bleeding, for 2 months postoperatively. The horse had acute colic secondary to a strangulating lipoma at 2 months and was euthanatized after exploratory celiotomy. Placement of embolization coils in the right palatine artery was conrmed by CT and necropsy. Conclusions: Severe epistaxis in the horse may be caused by a ruptured major palatine artery pseudoaneurysm. Occlusion of this vessel can be successfully accomplished by transarterial coil embolization. Severe epistaxis in the horse has been reported secondary to guttural pouch mycosis, sinonasal trauma, and is occasion- ally associated with paranasal sinus neoplasia or ethmoid hematoma. Most commonly, rupture or erosion of the internal carotid, external carotid, and/or maxillary arteries have been reported to occur secondary to fungal infection of these vessels as they course through the guttural pouch.15 Transarterial coil embolization has been described in horses to control hemorrhage from the internal carotid, external carotid, and maxillary arteries individually or in combination with one another related to guttural pouch mycosis induced aneurysm.1,2 We are unaware of any reports describing transarterial coil embolization to control hemorrhage from other sites of aneurysm or pseudoaneurysm in the horse. Our objective was to report an unusual cause of lifethreatening hemorrhage in the horse and to describe the technique of transarterial coil embolization to successfully occlude the affected vessel. CLINICAL REPORT A 24yearold Morgan gelding (482 kg) was admitted for evaluation of moderate to severe rightsided epistaxis. Moderate to severe bleeding from the right nostril was noted 3 weeks before, and again 6 days before admission. Right sided guttural pouch mycosis was suspected based on the severity of hemorrhage and endoscopic observation of clotted blood at the right salpingopharyngeal opening. The horse had been treated with sulfamethoxazole trimethoprim since the rst episode of bleeding and was also being administered isoxsuprine, cyproheptadine, and levothyroxine (ThyroL, Usp, Lloyd, Inc., Shenandoah, IA) for management of equine pituitary pars intermedia dysfunction and chronic laminitis. On admission, the gelding was quiet, alert, responsive, and afebrile, with a heart rate of 52 beats/min and respiratory rate of 20 breaths/min. Mucous membranes were pale pink with a capillary rell time of 12 seconds. A moderate amount of blood was observed on the muzzle, chest, and forelimbs. No other abnormalities were identies on physical examination. On hematologic examination, there was anemia (PCV, 16%), mild hypoproteinemia (5.4 g/dL) and a blood lactate of 2.1 mmol/L. Endoscopic examination of the upper airway revealed a region of swollen red tissue interpreted as hematoma in the pharynx, immediately rostral to the right salpingopharyngeal opening (Fig 1A). A small amount of fresh blood was seen at the right nasomaxillary opening. Both guttural pouches were Veterinary Surgery 43 (2014) 487494 Copyright 2014 by The American College of Veterinary Surgeons 487

2. free of blood and exudate. Skull radiographs revealed homogenous soft tissue opacity within the right rostral and caudal maxillary sinuses as well as the dorsal and ventral conchal sinuses, consistent with sinusitis and/or hemorrhage. There was no evidence of distortion of bony structures or uid line present in the paranasal sinuses. Widening of the periodontal space along the left upper PM3, PM4, M1 (Triadan 207, 208, 209) and mild remodeling of the tooth roots of the right upper PM3 and rostral root of PM4 (Triadan 107 and 108) were seen, indicating periodontal disease (Fig 1BD). Oral examination revealed good alignment of all premolar and molar teeth with mild points on the lingual surfaces of both mandibular cheek teeth arcades and the buccal surfaces of both maxillary cheek teeth arcades. There was no evidence of any fractures, stula, masses, or foreign bodies. Considering the signalment and history top differential diagnoses were neoplasia or ethmoid hematoma with unusual hemorrhage. Because of a lack of a denitive radiographic diagnosis, computed tomography (CT) was recommended to diagnose the problem and determine if surgical intervention would be an option. The day after admission, crossmatching was performed in preparation for blood transfusion before general anesthesia and if indicated during/after any potential surgical intervention. Based on the geldings anemia and continued mild epistaxis, 4 L whole blood was administered before anesthesia. Immediately after the horse was anesthetized and positioned in dorsal recumbency for the CTscan, there was profuse hemorrhage from the right nostril. Additional whole blood was transfused and the right nasal cavity was packed to help reduce hemorrhage during CT. On the CT scan, there was diffuse soft tissue attenuating material that lled the entire right paranasal sinuses as well as the nasopharynx (interpreted as hemorrhage). The areas of attenuating material were later analyzed using Hounseld units (HU) and were determined to have a CT density of $60 HU. This value of Hounseld unit falls within the range of fresh blood, early hematoma, and some soft tissue structures.6 Unfortunately, because of the severity of hemorrhage that started before CT evaluation, the entire right paranasal sinuses were completely lled with blood which may have masked an accurate diagnosis of any potential difference in CT density of an abnormal soft tissue structures versus fresh hemorrhage. CT images demonstrated the presence of both expansion and lysis of the right wing of the basisphenoid bone and right maxillary Figure 1 (A) Endoscopic image showing hematoma (white arrows) on the right pharyngeal wall immediately rostral to the right salpingopharyngeal opening (black arrow). (B) Dorsoventral radiograph of the skull demonstrating increased radiopacity in the right paranasal sinuses (outlined by black arrows). (C) Right lateral oblique radiograph of the skull demonstrating increased radiopacity within the right paranasal sinuses compared to the left (Fig 1D). Mild widening of the periodontal space and remodeling of the tooth roots of the right upper PM3 and rostral root of PM4 (black arrows). (D) Left lateral oblique radiograph of the skull demonstrating mild widening of the periodontal space along the left upper PM3, PM4, M1 (black arrows). The left paranasal sinuses appear clear (radiolucent) in this image. 488 Veterinary Surgery 43 (2014) 487494 Copyright 2014 by The American College of Veterinary Surgeons Coil Embolization of a Palatine Artery Pseudoaneurysm McClellan et al. 3. bone of the ventral aspect of the caudal maxillary sinus, including the bone surrounding the right maxillary third molar and right ventral aspect of the infraorbital canal (Fig 2AC). These CT ndings did not denitively diagnose the problem, but with the bony lysis and expansile nature of the lesion, neoplasia or large sinus ethmoid hematoma was considered highly likely. During the CT scan, mean arterial blood pressure decreased to 52 mmHg. The previously placed nasal cavity packing was producing an inadequate level of hemostasis, so the decision was made to stop the CT scan and proceed to emergency temporary ligation of the right common carotid artery. The right neck was clipped and scrubbed with chlohexidine and alcohol. A 7 cm skin incision was made immediately dorsal to the jugular vein in the right midcervical region. The incision was then extended through the brachio- cephalicus and omohyoid muscles using a combination of blunt and sharp dissection. Once located, the right carotid sheath was carefully incised so that the right carotid artery could be isolated from both the vagosympathetic trunk and recurrent laryngeal nerve. Once isolated, the right common carotid was ligated using sterile umbilical tape. The hemor- rhage appeared to decrease after carotid artery ligation, but did not stop completely. Therefore, the decision was made to proceed directly to surgery for an emergency right frontonasal sinusotomy in an attempt to achieve both a denitive diagnosis and stop the hemorrhage by application of direct pressure with gauze packing. The right frontonasal sinus region was prepared for a frontonasal sinu