Chapter 66 Surgery of the Esophagus
In general, the signs of esophageal disease are related to loss of function, to obstruction, or to inflammation of the esophagus and the surrounding structures. Surgery on the esophagus probably requires more skill and precision than any other portion of the alimentary tract. The esophagus is constantly moving, lacks a serosal layer, and does not have omentum to help seal small leaks. If suture line reinforcement is necessary, adjacent muscle, diaphragmatic tissue, or pericardium may be used. Extra-abdominal movement of omentum on a pedicle through a rent in the diaphragm can also be used for this purpose.
ANATOMY
Upper Esophageal Sphincter
• Innervation of the cricopharyngeal muscle is from branches of the glossopharyngeal and vagus nerves.
Lower Esophageal Sphincter
• The pinchcock effect of the diaphragmatic hiatus is thought to assist in preventing gastroesophageal reflux.
CRICOPHARYNGEAL ACHALASIA
• This rare form of dysphagia is characterized by inadequate relaxation of the cricopharyngeal muscle and affects primarily young animals.
Preoperative Considerations
As described in Chapter 4, perform barium swallow fluoroscopy preoperatively to distinguish cricopharyngeal achalasia from other forms of oropharyngeal dysphagia and to evaluate motility of the body of the esophagus. Evaluate for aspiration pneumonia and treat accordingly.
Surgical Procedure (Cricopharyngeal Myectomy)
Technique
2. Aseptically prepare the ventral portion of the neck, from the angle of the mandible to the manubrium.
3. Make a ventral midline cervical incision, starting just cranial to the larynx and extending caudally 15 to 20 cm.
5. Expose the dorsum of the trachea by rotating the larynx and trachea 180 degrees in either direction. If working on the dog’s right side, pull the trachea to the right.
6. Remove a thin layer of connective tissue, expos-ing the dorsal aspect of the cricopharyngeal musculature.
7. Incise the cricopharyngeal musculature on its midline. Gently elevate the muscle from the underlying esophagus with meticulous and careful blunt dissection. Consider placing an inflated Foley catheter or endotracheal tube in the esophagus to help delineate the structures.
9. Cut the halves of the muscle belly along their lateral attachments and remove the muscle (Fig. 66-1).
10. Allow the larynx and trachea to return to their normal position, and appose the sternohyoideus muscle with a continuous suture, using 4-0 synthetic absorbable suture.
Postoperative Care and Complications
Short-Term
• If oral phase dysphagia is present (see Chapter 65), there may not be any improvement seen following surgery.
• If pharyngeal phase dysphagia is present (see Chapter 65) concurrently, a cricopharyngeal myectomy may worsen the animal’s signs and the aspiration pneumonia.
• Hypomotility of the proximal esophagus may interfere with a successful outcome. Food and liquids pass more easily through the cricopharyngeal sphincter, but decreased clearance by the esophagus enhances the likelihood of stasis and retrograde movement of material into the trachea. Aspiration pneumonia continues to be a problem.
VASCULAR RING ANOMALY
Preoperative Considerations
• Most animals with a vascular ring anomaly are presented to the veterinarian at the age of 4 to 10 weeks. Rarely, an animal may reach adulthood before a vascular ring anomaly is diagnosed.
• Evaluate the lungs radiographically for aspiration pneumonia. If necessary, institute antibiotic therapy several days preoperatively.
• Debilitated animals may benefit from hyperalimentation via a gastrostomy tube (see Chapter 3) for 7 to 10 days before surgery.
Surgical Procedure
Technique
2. Aseptically prepare the left lateral thoracic wall from three intercostal spaces above to five spaces below the fourth intercostal space.
3. To approach the vascular ring, perform a thoracotomy through the fourth intercostal space (see Chapter 167 for thoracotomy technique).
4. Identify the ligamentum arteriosus, which is a constricting band encircling the esophagus. In a PRAA, the aorta is on the animal’s right side and cannot be seen through a left thoracotomy (see Fig. 85-1).
5. If a PRAA is not the problem, consider vascular anomaly variations, including a left subclavian artery originating from the brachiocephalic trunk and, less commonly, a double aortic arch.
7. Gently dissect the mediastinum and adventitia away from the esophagus 1 to 2 cm above and below the constricted portion. Dissect any restricting bands of tissue away from the esophagus.
8. Pass a large Foley catheter or balloon dilator into the esophagus per os to further expand the esophagus at the site of constriction.
Postoperative Care and Complications
Short-Term
• Evacuate the pleural cavity and administer mepivacaine through the indwelling chest tube to control pain as necessary postoperatively. The chest tube usually can be removed within 24 hours.
ESOPHAGOTOMY
Preoperative Considerations
• Place a large-bore tube in the esophagus just before an esophagotomy to aspirate esophageal contents, act as a support while incising into the lumen of the esophagus, and help immobilize the esophagus.
• Although surgery of the esophagus carries a low risk of postoperative infection, some contamination occurs. Perioperative antibiotics are recommended (given 30 minutes before surgery and repeated once or twice). The antibiotic chosen should be effective against gram-positive pathogens (e.g., a cephalosporin).
