Gastro-esophageal: bolus passes through gastro-esophageal sphincter into stomach.
Normal function requires coordinated action of all sphincters and phases of swallowing.
Approach to the feline esophageal case
Signalment: young age → congenital disorders; old age → degenerative/neoplastic disease.
Detailed clinical history is a prerequisite.
Examination for concomitant or complicating problems: chest auscultation; temperature monitoring, etc.
Hospitalization: observe ingestion of food, any regurgitation, noting timing and patterns and whether the consistency of the food affects the patient's responses.
Baseline hematological, biochemical and serological parameters.
Common clinical signs of esophageal disease
Regurgitation: differentiate from vomiting.
Cough: may indicate aspiration pneumonia.
Dysphagia: may indicate disturbance of cranial esophageal sphincter.
Dyspnea: caused by aspiration pneumonia, pain, esophageal perforation, mediastinitis, pleuritis etc.
Ptyalism: blood-tinged with foreign bodies or esophageal ulceration/necrosis.
Pyrexia: in secondary pneumonias.
Weight loss: common in chronic disorders of the esophagus.
Non-specific signs: pain and depression associated with esophagitis, mediastinitis and pleuritis.
Passive, no abdominal effort, undigested food, tubular-shaped regurgitated material.
Active retching, abdominal contractions, partly digested food with bile present.
Diagnostic modalities in esophageal disease
Radiography: plain, contrast (barium, aqueous iodine) and fluoroscopic studies all helpful.Be careful of barium if suspicion of esphogeal perforation.
Endoscopy: rigid and flexible.
Basic surgical principles
No serosal layer in esophagus therefore careful suturing required to produce water-tight closure.
It is commonly thought that the mucosal layer holds most strength. However, studies have questioned this concept. Dallman (1988) showed that in dogs the submucosa alone had the same holding strength as the submucosa and mucosa together.
Suture line reinforcement can be achieved:
Intercostal muscle pedicles.
Avoid suture line tension, which can produce dehiscence.
Debride to healthy edges before suturing (severely traumatized cervical esophagus and surrounding tissue can be managed as an open wound prior to delayed closure but gastrostomy tube feeding Gastrostomy: percutaneous tube (endoscopic) would be required).
In thorax, do not compromise the broncho-esophageal artery, the main blood supply to the thoracic esophagus.
Simple appositional sutures used in a two-layered closure of esophagus.
Layer 1: mucosa/submucosa is the most important, and strongest layer. Place knots in esophageal lumen. Use interrupted sutures.
Layer 2: muscle/adventitia. Place knots outwith the adventitial layer.
Use synthetic absorbable swaged-on sutures in mucosa/submucosa and the same or monofilament non-absorbable material in the muscle/adventitia.
Size 3/0 or 4/0 should be suitable for most feline patients.
To form an esophageal end-to-end anastomosis
Occlude the lumen cranial and caudal to the resection with atraumatic clamps.
Start by reapposing the two cut edges of the esophagus by the use of stay sutures dorsally and ventrally in each portion.
Commence sutures on the outer aspect of the far wall of esophagus: close the muscle/adventitia here.
Next close the mucosa/submucosa on the far wall.
Move to near wall. Close the mucosa/submucosa.
Finally, close the muscle/adventitia on the near wall.
Reinforce the suture line if necessary (see above).
Approach to the esophagus
Cranial thoracic area: right lateral thoracotomy.
Caudal thoracic area: left lateral thoracotomy.
Median sternotomy gives large exposure, however, the esophagus will be in a deep location and careful mediastinal dissections will be required.
Summary of surgical conditions of the feline esophagus
Propulsion into stomach followed by gastrotomy (but bony material will dissolve).
Esophagotomy if other methods fail.
Post-operative: fluid support, antibiotics, nil by mouth 24-48 hours, gastrostomy tube nutrition for severely damaged esophagus (for 5-7 days).Always check the base of a cat's tongue for thread or wool entrapment.
Treatment: bougienage, balloon dilatation repeated weekly combined with prednisolone Prednisolone to limit fibroplasia.
Surgical intervention may be required: esophagoplasty to increase lumen or resection and anastomosis to resect the stricture completely.
Complications: minor hemorrhage after dilatation/bougienage; occasionally perforation.
Protrusion of distal esophagus/cardia through the esophageal hiatus of diaphragm.
Congenital and traumatic causes of enlarged diaphragmatic hiatus.
Signs: intermittent vomiting/regurgitation, gagging, dysphagia, weight loss, reflux esophagitis, dyspnea, obstruction in severe cases.
Diagnosis: radiography, fluoroscopy for intermittent 'sliding' hernias, endoscopy to diagnose secondary esophagitis. Application of broad abdominal pressure during fluoroscopy/radiography may help to diagnose sliding hernias.
Treatment: antacids, metoclopramide. If unresponsive, surgical objectives:
Increase resistance of lower esophageal sphincter.