Sequential gross, microscopic and roentgenographic features of acute feline esophagitis

Esophagitis in Cats and Dogs

Esophagitis in cats and dogs is a consequence of increased exposure of the esophageal mucosa to gastroduodenal reflux. Causes can include anesthesia-related reflux, frequent vomiting, or lodged foreign bodies. An exception is eosinophilic esophagitis, an emerging primary inflammatory disease of the esophagus with a presumed allergic etiology. Reflux esophagitis owing to lower esophageal sphincter incompetence is often suspected; a tentative diagnosis can be made by endoscopic assessment, wireless esophageal pH-monitoring, or histologic examination. Because it can be difficult to distinguish diet-responsive upper gastrointestinal disease from esophagitis, response to treatment with gastric acid suppressants is needed to confirm the tentative diagnosis.

Prevalence of Gastroesophageal Reflux in Cats During Anesthesia and Effect of Omeprazole on Gastric pH

Background

Gastroesophageal reflux (GER) is poorly characterized in anesthetized cats, but can cause aspiration pneumonia, esophagitis, and esophageal stricture formation.

Objective

To determine whether pre‐anesthetic orally administered omeprazole increases gastric and esophageal pH and increases serum gastrin concentrations in anesthetized cats, and to determine the prevalence of GER using combined multichannel impedance and pH monitoring.

Animals

Twenty‐seven healthy cats undergoing elective dental procedures.

Methods

Prospective, double‐masked, placebo‐controlled, randomized clinical trial. Cats were randomized to receive 2 PO doses of omeprazole (1.45–2.20 mg/kg) or an empty gelatin capsule placebo 18–24 hours and 4 hours before anesthetic induction. Blood for measurement of serum gastrin concentration was collected during anesthetic induction. An esophageal pH/impedance catheter was utilized to continuously measure esophageal pH and detect GER throughout anesthesia.

Results

Mean gastric pH in the cats that received omeprazole was 7.2 ± 0.4 (range, 6.6–7.8) and was significantly higher than the pH in cats that received the placebo 2.8 ± 1.0 (range, 1.3–4.1; P < .001). Omeprazole administration was not associated with a significant increase in serum gastrin concentration (P = .616). Nine of 27 cats (33.3%) had ≥1 episode of GER during anesthesia.

Conclusions and Clinical Relevance

Pre‐anesthetic administration of 2 PO doses of omeprazole at a dosage of 1.45–2.20 mg/kg in cats was associated with a significant increase in gastric and esophageal pH within 24 hours, but was not associated with a significant increase in serum gastrin concentration. Prevalence of reflux events in cats during anesthesia was similar to that of dogs during anesthesia.

The influence of esomeprazole and cisapride on gastroesophageal reflux during anesthesia in dogs

BACKGROUND

Gastroesophageal reflux (GER) is common in anesthetized dogs and can cause esophagitis, esophageal stricture, and aspiration pneumonia.

OBJECTIVE

To determine whether preanesthetic IV administration of esomeprazole alone or esomeprazole and cisapride increases esophageal pH and decreases the frequency of GER in anesthetized dogs using combined multichannel impedance and pH monitoring.

ANIMALS

Sixty-one healthy dogs undergoing elective orthopedic surgery procedures.

METHODS

Prospective, randomized, placebo-controlled study. Dogs were randomized to receive IV saline (0.9% NaCl), esomeprazole (1 mg/kg) alone, or a combination of esomeprazole (1 mg/kg) and cisapride (1 mg/kg) 12-18 hours and 1-1.5 hours before anesthetic induction. An esophageal pH/impedance probe was utilized to measure esophageal pH and detect GER.

RESULTS

Eight of 21 dogs in the placebo group (38.1%), 8 of 22 dogs in the esomeprazole group (36%), and 2 of 18 dogs in the combined esomeprazole and cisapride group (11%) had ≥ 1 episode of GER on impedance testing during anesthesia (P < .05). Esomeprazole was associated with a significant increase in gastric and esophageal pH (P = .001), but the drug did not significantly decrease the frequency of GER (P = .955). Concurrent administration of cisapride was associated with a significant decrease in the number of reflux events (RE) compared to the placebo and esomeprazole groups (P < .05).

CONCLUSIONS AND CLINICAL RELEVANCE

Preanesthetic administration of cisapride and esomeprazole decreases the number of RE in anesthetized dogs, but administration of esomeprazole alone was associated with nonacid and weakly acidic reflux in all but 1 dog.

Reflux Esophagitis in Three Cats Associated With Metaplastic Columnar Esophageal Epithelium

Gastroesophageal reflux is a relatively common condition in dogs and cats and may lead to secondary reflux esophagitis. A consequence of chronic gastroesophageal reflux that is well described in humans is Barrett’s esophagus, which is the replacement of the normal squamous epithelium of the distal esophagus with metaplastic columnar epithelium. Three cats with clinical and endoscopic signs of chronic esophagitis had metaplastic columnar epithelium on biopsy of the distal esophageal mucosa. Suspected underlying causes were cardial incompetence and sliding hiatal hernia. Two cats had complete resolution of the clinical signs after treatment. One cat was euthanized.

Diagnosis and management of reflux esophagitis

Esophagitis has generally been considered rare in dogs and cats. However, it may not be as uncommon as previously thought due to the increased awareness of the disease and the increasing availability of endoscopy. Esophagitis can be caused by gastroesophageal reflux, trauma, foreign bodies, ingestion of caustic substances, structural abnormalities (ie, hiatal hernia, neoplasms), and chronic vomiting. This article will focus on the diagnosis and treatment of esophagitis secondary to gastroesophageal reflux. This is a diagnosis based on clinical signs, exclusion of other causes of esophagitis, and typical radiographic, endoscopic, and histopathologic findings.

Feline esophagitis secondary to gastroesophageal reflux disease: clinical signs and radiographic, endoscopic, and histopathological findings

Chronic esophagitis due to gastroesophageal reflux (GER) is rarely reported in the cat. This paper describes the clinical signs and diagnostic findings, including radiographic, endoscopic, and histopathological abnormalities, in three young, purebred, male cats with esophagitis presumed to be secondary to GER. Clinical signs included regurgitation, dysphagia, and weight loss. Contrast radiography revealed GER, esophageal dilatation, and decreased motility. Endoscopy showed hyperemia, increased vascularity, ulcers, erosion, and an abnormal lower esophageal sphincter. Histopathological lesions included squamous hyperplasia and dysplasia, erosions, ulcers, and an inflammatory infiltrate of lymphocytes, plasma cells, and neutrophils. Long-term follow-up demonstrated progression of the disease in two of the cats.

Pharyngeal pH monitoring in patients with posterior laryngitis

OBJECTIVE

To evaluate the diagnostic value of 3-site 24-hour ambulatory pH monitoring in patients with posterior laryngitis (PL) and the prevalence of esophageal abnormalities in this patient group.

METHODS

Twenty patients with PL and 17 healthy volunteers were studied as controls. Control subjects had transnasal esophagogastroduodenoscopy (T-EGD) and ambulatory pH monitoring. Patients underwent T-EGD, ambulatory pH monitoring, and barium esophagram.

RESULTS

T-EGD documented no abnormality in controls. Esophagitis was present in 2 PL patients, and hiatal hernia in 3. Ambulatory pH monitoring showed that 15 PL patients and 2 controls exhibited pharyngeal acid reflux. Barium esophagram documented gastroesophageal reflux in 5 PL patients. However, none of these barium reflux events reached the pharynx. All PL patients with barium esophagram evidence of gastroesophageal reflux also showed pharyngeal acid reflux by pH monitoring.

CONCLUSION

Pharyngeal acid reflux is more prevalent in patients with PL than in healthy controls. Patients with PL infrequently have esophageal sequelae of reflux disease. Ambulatory 24-hour simultaneous 3-site pharyngoesophageal pH monitoring detects gastroesophagopharyngeal acid reflux events in most patients with PL.

Motility changes in opossum esophagus from experimental esophagitis

We assessed how acute inflammation affects the contractile activity of the esophageal body. Two models of esophagitis were used: nine opossums had an esophageal perfusion of 100 meq hydrochloric acid for 2 hr and were studied at 24 hr. Ten had the perfusion for 4 h and their esophagitis were studied in vitro after 72 hr. Comparisons were made in all instances to animals who had esophageal saline perfusion for identical periods. All acid-perfused animals developed gross and histologic evidence of mucosal inflammation; in three animals, inflammatory changes extended into the submucosa and the muscularis propria. Manometric recordings in the acid-perfused animals revealed esophageal shortening, frequent failure of primary peristalsis and frequent occurrence of spontaneous contractions. Recordings of isometric tension of muscle in vitro revealed spontaneous contractions in strips from the mucosa and from the circular and from the longitudinal muscle. The amplitude of contractions in response to electrical stimulation was decreased, but the duration of contractions was increased largely because of a prolonged recovery phase. These changes in mechanical response occurred with stimulus parameters directed at both the muscle and the intrinsic nerves. We conclude that esophageal inflammation can lead to an increased irritability and decreased stimulus response of the smooth muscle of the esophagus even where it is not directly involved in an inflammatory response. These changes correspond to the functional abnormalities of the esophagus seen in patients with reflux esophagitis.

Esophageal motor function and response to acid perfusion in patients with symptomatic reflux esophagitis

There is much evidence to suggest that peristaltic function is defective in esophagitis patients and that this defect may contribute to prolonged acid exposure, promoting esophageal mucosal injury. Abnormal peristalsis may also be related to the generation of reflux symptoms. We evaluated primary peristalsis and its relationship to symptoms under basal conditions and during saline and HCl perfusion in 15 symptomatic reflux patients with gross esophagitis and 15 healthy controls. In the basal state, LES pressure (15.3 vs 25.1 mm Hg) and peristaltic amplitude (74.2 vs 104.8 mm Hg) were significantly lower in subjects with gastroesophageal reflux disease (GERD) (P less than 0.05). During HCl perfusion, peristaltic amplitude and duration increased slightly, and peristaltic velocity slightly decreased similarly in both groups. There was no difference in the incidence of nonpropagated, segmental, or swallow-initiated simultaneous contractions, or change in resting intraesophageal pressure during HCl perfusion in control and GERD groups. This study identified abnormal contractile amplitude as a specific defect in the primary peristaltic wave of esophagitis patients but does not support a role for acid-induced motility changes in the generation of symptoms in GERD.

New concepts and methods in the study and treatment of gastroesophageal reflux disease

This paper reviews progress in the use of 24-hour distal esophageal pH monitoring in the study of gastroesophageal reflux. This technique records acid exposure as numbers of reflux episodes and time required by the esophagus to return this acid juice to the stomach. These data afford an opportunity to conceptualize the pathophysiology of gastroesophageal reflux disease in relation to physiologic activities such as alimentation, sleep, and postural change. This knowledge will enable the clinician to critically focus attention on important issues of patient management and therapy as they relate to the pathophysiology of this disease.

Acid clearance during sleep in the pathogenesis of reflux esophagitis

Impaired esophageal clearing of refluxed gastric contents during sleep has been implicated in the pathogenesis of reflux esophagitis. To more directly evaluate this hypothesis, 13 symptomatic patients with esophagitis and 13 normal controls had 15 ml of 0.1 N HCl instilled into the esophagus in the recumbent position while awake and during polygraphically monitored sleep. When sleep was maintained for the majority of the acid-clearing duration, the clearance times for both patients and controls were significantly prolonged when compared to those while awake (P less than 0.01). However, when sleep was maintained for less than 50% of the acid-clearing interval, the patients showed significantly longer acid clearance times. The swallowing rate did not differentiate the two groups under any condition. These data show that sleep impairs esophageal acid clearance. Acid clearance occurred predominantly in association with arousals from sleep. The defective acid clearance found in patients with esophagitis probably plays a major role in the pathogenesis of this disorder.

Esophageal epithelial response to gastroesophageal reflux. A quantitative study

Exposure of the distal esophageal mucosa to acid gastric juice was quantitated by 24-hr pH monitoring in 100 individuals and was correlated with morphologic data derived from esophageal biopsies. The degree of acid exposure to the distal esophagus correlated directly with increases in both relative and absolute length of the subepithelial papillae and to relative basal zone hyperplasia. Both papillary length and basal zone hyperplasia decreased after antireflux surgery had reduced acid exposure to normal. Reflux in the recumbent position resulted in prolonged exposure of the mucosa to acid because of poor acid clearing from the esophagus. This caused longer papillae than did upright reflux, where there were more frequent reflux episodes, but with rapid acid clearance. The presence of a hiatal hernia was associated with longer papillae, lower DES pressure, increased reflux frequency, and prolonged recumbent acid clearance. Twenty-four hour pH monitoring correlated better with papillary length than did symptoms or other clinical measures of gastroesophageal reflux.