Tube Diverticulum Research Articles

Guttural pouch equine: topography and vascularization

The guttural pouch is a diverticulum of the auditory tube, the function of which hasn’t been fully understood yet. The work reveals the anatomy and topography of the guttural pouch. This knowledge is necessary for the treatment of mycosis of the guttural pouch, disease leading to toxic hepatitis. The examination includes postmortem dissection, sagittal head section, and cerebral bilateral angioradiography. The auditory tube diverticulum is a complex anatomical structure, consisting of a volumetric cavity, divided by the stylohyoid into rostral and caudal sections. Large maxillary, external and internal carotid arteries, some cranial nerves pass along the lateral wall of the diverticulum. The tissues of the wall of the diverticulum are affected by the angiotropic fungus Aspergillus fumigatus. The main role of the studied arteries in mycosis of the guttural pouch wall is to provide the pathogenic fungus with nutrients, which leads to destruction of vascular wall and lethal epistaxis. The placement of arteries near the most important cranial nerves causes the damage of them and the development of severe neurological disorders. The diameter of the arteries determines the choice of occlusive material for the surgical treatment of mycosis. Latin anatomical terminology corresponds to the 6th edition of the International Veterinary Anatomical Nomenclature.

Partial resection of the plica salpingopharyngeus for the treatment of three foals with bilateral tympany of the auditory tube diverticulum (guttural pouch)

3 foals were referred for treatment of tympany of the auditory tube diverticulum (guttural pouch). Bilateral guttural pouch tympany was diagnosed in all 3 foals on the basis of clinical signs and results of radiographic and endoscopic evaluations and gutturocentesis. In each foal, previous medical or surgical interventions or both had failed to correct the problem. Bilateral surgical resection of the plica salpingopharyngeus was performed. Follow-up telephone interviews with owners 8 months to 3 years after surgery revealed that long-term resolution of the tympany had been achieved in each foal, with few to no postsurgical complications. Surgical correction of refractory bilateral guttural pouch tympany can be accomplished by resection of the plica salpingopharyngeus within the pharyngeal opening of the Eustachian tube. In the foals of this report, permanent resolution of tympany was apparently achieved without interfering with upper airway function, providing support for the use of surgical resection of the plica salpingopharyngeus in the treatment of bilateral guttural pouch tympany.

Treatment of acute epistaxis secondary to guttural pouch mycosis with transarterial nitinol vascular occlusion plugs in three equids

2 horses and 1 pony were evaluated for right-sided (1 horse and the pony) and left-sided (1 horse) acute epistaxis of 1 day's to 1 month's duration. Endoscopic examination of the 3 equids revealed that the hemorrhage originated from the right maxillary artery in 2 equids and from the left internal carotid artery in the third. Mycosis of the auditory tube diverticulum (guttural pouch) was detected in all 3 equids. All 3 equids underwent surgery, and transarterial nitinol intravascular plugs were placed to occlude affected blood vessels. All equids survived for a long period (ie, a minimum of 1 to 2 years) and returned to their previous use. All had complete regression of clinical signs of guttural pouch mycosis without additional medical treatment. The use of transarterial nitinol intravascular plugs appeared to be an effective alternative to other techniques for the treatment of epistaxis secondary to guttural pouch mycosis, including transarterial occlusion devices such as embolization coils.

Eustachian tube diverticulum chondroids and neck abscessation in a case of Streptococcus equi subsp. equi : clinical communication

A 12-year-old, grey, crossbred pony mare was presented with a swelling in the neck over the area of the 2nd cervical vertebra (C2), which was found to be painful on palpation. The neck was held stiffly. Radiography of the cervical region showed a focal area of increased radio-opacity over the dorsal, caudal and lateral aspect of the dorsal spinous process of C2. Ultrasound confirmed the presence of a hypoechoic area approximately 15 cm in diameter superimposed over the dorsal spinous process of C2. An aspirate was taken of the mass, which revealed purulent exudate confirming the diagnosis of an abscess. The abscess was lanced with a scalpel blade and samples of the purulent material revealed a pure culture of Streptococcus equi subsp. equi. The guttural pouches (Eustachian tube diverticulae (ETD)) were then evaluated endoscopically and multiple chondroids were seen filling most of the right ETD. Surgery was subsequently performed and 189 chondroids were removed via a right-sided hyovertebrotomy. The ETDs were flushed and penicillin installed into both ETDs on 3 different occasions via a catheter introduced using a fibre optic scope. This procedure was repeated until a negative culture status was achieved in order to eliminate the carrier status.

Progression of mycosis of the auditory tube diverticulum (guttural pouch) after arterial occlusion in a horse with contralateral temporohyoid osteoarthropathy

A 6-year-old Appaloosa mare was examined because of inappetance, difficulty eating, and swelling and mucopurulent discharge in the right eye. Results of a CBC and serum bio-chemical analysis revealed no important findings. Ophthalmologic examination revealed scarring and ulceration of the superficial layers of the cornea. Endoscopic examination of the upper portion of the respiratory tract and auditory tube diverticula (guttural pouches) revealed abnormal thickness of the right stylohyoid bone and a plaque suggestive of mycotic growth on the left internal carotid artery. Radiographic examination revealed right-sided otitis media. Temporohyoid osteoarthropathy in the right guttural pouch and mycosis in the left guttural pouch were diagnosed. Ceratohyoidectomy of the right stylohyoid bone was performed, and the left internal carotid artery was occluded via placement of stainless steel spring embolization coils. The mare regained the ability to eat without difficulty and improved clinically for approximately 4 weeks. However, the mare returned to the medical center 53 days after surgery with left-sided Horner syndrome, atrophy of the right side of the tongue, and a 3-week history of dysphagia and weight loss. Endoscopic evaluation revealed progression of mycotic growth in the left guttural pouch. The mare was euthanatized. Although the mycotic lesion in the left guttural pouch was an incidental finding at the time of initial examination, the lesion progressed to cause dysphagia and Horner syndrome after occlusion of the left internal carotid artery, a treatment that is typically associated with resolution of guttural pouch mycosis. Arterial occlusion is not necessarily a reliable method of resolving guttural pouch mycosis.

Detachable latex balloon occlusion of an internal carotid artery with an aberrant branch in a horse with guttural pouch (auditory tube diverticulum) mycosis

An aberrant branch of the internal carotid artery was detected by angiography in a horse with guttural pouch (auditory tube diverticulum) mycosis after the distal portion of the artery had been occluded by use of a detachable latex balloon. A second balloon was placed to eliminate retrograde hemorrhage from the aberrant branch. The horse recovered and returned to its previous activity. Vascular anomalies of the internal carotid artery my be more common than expected, and have resulted in fatal complications during and after surgical treatment in guttural pouch mycosis. Intraoperative identification of vascular anomalies by use of angiography may avoid these fatal complications.

Macroscopic anatomy of the auditory tube diverticulum (guttural pouch) in the thoroughbred equine--a silicon mold approach.

The characteristics of the equine auditory tube diverticulum (guttural pouches) were studied in detail by the naked eye and silicon mold method. First, we examined the anatomical relationship between the guttural pouches and their associated bones and muscles. Secondly, a silicon mold was fabricated to clarify the three-dimensional aspect of the guttural pouches, paying a special attention to the distribution of major arteries and nerves surrounding it. Thirdly, the volume of the silicon mold was measured by immersing it in water. The guttural pouches are a pair of pouches located dorso-posteriorly to the posterior pharynx. The pouches had a close contact rostrally with the Os sphenoidale, ventrally with the pharynx and the esophagus, and caudally with the Articulatio atlantoaxialis. The left and right guttural pouches had almost the same capacity in each horse. The A. carotis interna, cranial ganglia of cervical nerves and cervical Truncus sympathicus, as well as the N. vagus, N. glossopharyngeus, N. hypoglossus, and Radices spinales of the N. accessorius, were present in the mucosal crease extending from the roof of the guttural pouches towards the middle of the caudal wall. The N. facialis appeared from the Foramen stylomastoideum ran dorsocaudally along the lateral recess. The N. mandibularis appeared from the Foramen lacerum went over the muscular process of an ear bone, ran along the roof of the lateral recess and finally continued with the rostral side of the guttural pouches. Lymph nodes, scattered on the mucosal surface, appeared as tiny indentations with approximately millet seed size on the silicon surface. The capacity of guttural pouches in adult horses (472 +/- 12.4 cm3) was three-fold larger than that in foals (145 +/- 9.4 cm3).

Histological and morphometrical studies on the mucosa of the equine guttural pouch (auditory tube diverticulum).

The present study attempted to clarify the characteristics of the guttural pouch mucosa in equines and to evaluate its foreign substance clearance ability. The specimens were collected from nine regions (eight in the guttural pouch mucosa, and one in the nasopharynx mucosa). We first examined the pouch mucosa by light and electron microscopy. We then measured the frequency of goblet cells per 200 epithelial cells, the length of the cilia, the thickness of the epithelial cell layer and lamina propria and statistically analyzed the data. The guttural pouch mucosa consisted of stratified columnar epithelia with brush-like cilia, and there were almost no histological differences between adults and foals. The morphometrical study revealed significant differences in goblet cell frequency (p < 0.001) and the thickness of lamina propria (p < 0.05). By contrast, no statistically significant difference was detected in the length of the cilia or the thickness of the epithelial cell layer. These findings suggest that the guttural pouch mucosa provides foreign substance clearance ability, but that its ability varies among different regions of the epithelium.

Empyema of the guttural pouch (auditory tube diverticulum) in horses: 91 cases (1977–1997)

Objective To identify features of guttural pouch (auditory tube diverticulum) empyema in horses and compare findings of uncomplicated guttural pouch empyema with guttural pouch empyema complicated by chondroids. Design Retrospective study. Animals 91 horses with guttural pouch empyema. Procedure Medical records of horses with guttural pouch empyema were reviewed. Results The most common owner complaint and abnormal finding was persistent nasal discharge. Chondroids were detected in 21% (19/91) of affected horses. Streptococcus equi was isolated from the guttural pouch in 14 of 44 horses; for Streptococcus spp, in vitro resistance to sulfadimethoxine and trimethoprim-sulfamethoxazole was detected. Retropharyngeal swelling and pharyngeal narrowing were significantly more prevalent in horses with chondroids, compared with horses with uncomplicated empyema. Ninety-three percent of affected horses were discharged from the hospital; at time of discharge, 66% had complete resolution of disease, 19% had improvement without resolution, and 15% did not have improvement. Conclusions and Clinical Relevance Horses with persistent nasal discharge should be examined endoscopically for guttural pouch empyema. Treatment with lavage offers a good prognosis for resolution of uncomplicated guttural pouch empyema. Aggressive treatment with lavage and endoscopic snare removal of chondroids offers a good prognosis and may make surgical intervention unnecessary. (J Am Vet Med Assoc 1999;215:1666–1670)

CT examination of the guttural pouch (auditory tube diverticulum) in Przewalski's Horse (Equus przewalskii).

The domestic horse (Equus caballus) have the large symmetrical guttural pouches (the auditory tube diverticulum) formed by saccate bulge of the auditory tube. In this study, CT examination was carried out in the head of Przewalski's horse (Equus przewalskii), the only true wild horse living at present. As results of the examination, Przewalski's horse possessed the large symmetrical guttural pouches divided into medial and lateral compartments by the stylohyoid bone. Moreover, the right and left guttural pouches meet each other at the median part to form a thin septum. As CT sections get close to the part of the occipital condyle, the lateral compartment disappeared, and the medial compartment gradually became small toward the base of the skull. These results indicate that the nuchal-basal part of the medial compartment is not well-developed as compared with the domestic horse.

Effect of bilateral blockade of the pharyngeal branch of the vagus nerve on soft palate function in horses

Abstract Objective To determine the effect of bilateral blockade of the pharyngeal branch of the vagus nerve on soft palate function in horses. Animals 5 Standardbreds. Procedure Peak tracheal inspiratory and expiratory pressures and airflow were measured while horses exercised at the speeds corresponding to 75 and 100% of the speed that resulted in maximal heart rate, with and without pharyngeal branch of the vagus nerve blockade. Respiratory frequency-to-stride frequency coupling ratio was measured by correlating foot fall measurements with respiratory frequency. The pharyngeal branch of the vagus nerve was blocked bilaterally as the nerve coursed through the auditory tube diverticulum (guttural pouch) across the longus capitus muscle. Results Persistent, reversible dorsal displacement of the soft palate (DDSP) occurred in all horses after nerve blockade, and lasted from 1 to 3 hours; normal nasopharyngeal function returned within 3 hours. Compared with control values, peak expiratory tracheal pressure increased (P = 0.001), expiratory impedance increased (P = 0.007), and minute ventilation decreased (P = 0.04). Respiratory frequency-to-stride frequency coupling ratio decreased (P = 0.009) so that horses took 1 breath/stride without the nerve block and, approximately, 1 breath/2 strides with the block. Conclusion DDSP creates flow-limiting expiratory obstruction and may be caused by neuromuscular dysfunction involving the pharyngeal branch of the vagus nerve. It may alter performance by causing expiratory obstruction and by altering breathing strategy in horses. Clinical Relevance A repeatable, reversible model of DDSP exists that allows further study of the disease. Dysfunction of the neuromuscular group, pharyngeal branch of the vagus nerve and palatinus and palatopharyngeus muscles, may be implicated in the pathogenesis of clinical DDSP. (Am J Vet Res 1998;59:504–508)

Detection of antibodies to Aspergillus fumigatus in serum of horses with mycosis of the auditory tube diverticulum (guttural pouch)

SUMMARY Objective To detect antibodies against Aspergillus fumigatus antigens in serum samples from horses and to evaluate the relevance of this method as an alternative approach to the diagnosis of mycosis of the auditory tube diverticulum (guttural pouch mycosis [GPM]). Animals Twelve clinically normal horses (controls) and 12 horses with GPM diagnosed by endoscopic observation of characteristic mycotic plaques. Procedure Antibodies to A fumigatus antigens were detected in serum by use of an ELISA and immunoblot analysis with extracellular antigens. Results Antibodies against A fumigatus antigens were found in healthy and diseased horses. Titer of total Aspergillus antibodies was not diagnostic for GPM. In contrast, immunoblot analysis results indicated that 2 antigens of 22 and 26 kd were constantly recognized by sera from diseased horses. Conclusions Reactivity to 22- and 26-kd A fumigatus antigens, as measured by immunoblot analysis, seemed to be diagnostic for GPM in horses. (Am J Vet Res 1997;58:1364–1366)

Lipid analysis of lavage samples from the equine guttural pouch (auditory tube diverticulum).

The guttural pouch is a large, air-filled diverticulum of the auditory tube, present in the horse and other species. Lipid analysis of saline lavage from the equine guttural pouch has demonstrated the presence of phospholipids and neutral lipids in amounts that are variable but consistently greater than in any other species described. A stain specific for choline-containing phospholipids has demonstrated the presence of phospholipid-containing vesicles only within the cells of subepithelial, seromucoidlike glands, suggesting that these cells incorporate phospholipids in their secretions. The functional significance of surface-active agents in the guttural pouch may be different from that proposed for other species because of the unique anatomical design and the different proposed functions of the guttural pouch.

Clinical and endoscopic study to estimate the incidence of distal respiratory tract infection in Thoroughbred foals on Ontario breeding farms

Summary Respiratory tract infections are prevalent in foals, yet the frequency with which the distal airways are affected in clinical episodes of respiratory tract disease has not been evaluated to our knowledge. The objective of the study was to determine the incidence of distal respiratory tract infection (drti) in foals on a sample of Thoroughbred breeding farms (n = 10) in Ontario. In a pilot study, clinical criteria commonly used to select foals for antimicrobial treatment (detection of abnormal lung sounds, plus nasal discharge, cough, fever, tachypnea, and/or lethargy) were found to segregate foals with and without endoscopically confirmed drti. Mucopurulent exudate and bronchial erythema were observed more frequently (P &lt; 0.005), bronchial lavage total cell count and neutrophil concentration were significantly (P &lt; 0.005) higher, and intracellular cocci were recovered significantly (P &lt; 0.01) more often from bronchial lavage samples of affected foals (n = 8) than of controls (n = 8). These clinical criteria were used to identify cases in a cohort of Thoroughbred foals (n = 219) from May 1 to October 30, 1991. Case morbidity adjusted for clustering was 82 ± 5% (95% confidence limits, 72 to 92%). Most (74%) episodes of clinical drti were detected in July and August, and equal numbers were detected before (53%) and after (47%) weaning of foals. Of 178 cases, 66 (48%) were selected at random for endoscopy and bronchial lavage. Grade-II pharyngeal lymphoid hyperplasia was observed commonly (60% of foals); auditory tube diverticulum (guttural pouch) discharge was observed in 18 of 86 (21%) foals, and guttural pouch infection was confirmed in 6 of 7 foals examined endoscopically. Endoscopically confirmed drti, defined as visual detection of bronchial exudate with microscopic detection of intracellular cocci and markedly high neutrophil count in bronchial lavage samples, was confirmed in 75 of 86 (87%) cases tested. These data indicate that drti might be reliably diagnosed by auscultation during a simple rebreathing exercise. The syndrome of drti was extremely common in Thoroughbred foals, characterized by marked inflammation of visible airways and cytologic evidence of bacterial infection. Risk factors for clinical (undifferentiated) drti were not identified in this study.

Hemorrhage into the guttural pouch (auditory tube diverticulum) associated with rupture of the longus capitis muscle in three horses

Hemorrhage into the guttural pouch (auditory tube diverticulum) associated with rupture of the longus capitis muscle in three horses

Cystic structures in the guttural pouch (auditory tube diverticulum) of two horses

Cystic structures in the guttural pouch (auditory tube diverticulum) of two horses

The auditory tube diverticulum (ATD) in health and disease: neurological considerations

The auditory tube diverticulum (ATD) in health and disease: neurological considerations

The Auditory Tube Diverticulum (Guttural Pouch) in the Horse: Its Radiographic Examination

The Auditory Tube Diverticulum (Guttural Pouch) in the Horse: Its Radiographic Examination

Tympany of the eustachian tube diverticulum (gutteral pouch) in a foal.

SUMMARYThe successful surgical treatment of tympany of the guttural pouch in a 3 months old Arabian filly foal is recorded and the abnormality of the pharyngeal orifice is described. A brief review of the literature regarding the aetiology and treatment of the condition is given and two approaches to surgical treatment are briefly discussed.RÉSUMÉUne intervention chirurgicale réussie pour guèrir le tympanisme d'une poche gutturale sur une pouliche arabe agée de trois mois est décrite. On décrit également l'anomalie de l'orifice pharyngien, responsable de ce tympanisme.L'article passe en revue la littérature pour ce qui a trait à l'étiologie et au traitement de cette condition. Deux approches chirurgicales sont indiquées.ZUSAMMENFASSUNGDie erfolgreiche, chirurgische Therapie einer Luftsacktympanie bei einem 3 Monate alten Araber‐Stutfohlen wird wiedergegeben. Die Abnormalität der Oeffnung in den Pharynx wird beschrieben. Der Autor bespricht die Literatur über Aetiologie und Behandlung des Leidens und zwei verschiedene Operationsmethoden.

Instrument specifications for endoscopy of the equine upper respiratory tract and eustachian tube diverticulum.

Instrument specifications for endoscopy of the equine upper respiratory tract and eustachian tube diverticulum.