Equine Oral, Esophageal and Rectal disorders
Esophageal anatomy and surgery
Anatomy / Physiology
1. Passes to left of trachea at level of C4; accompanied by common carotid, vagosympathetic trunk, and recurrent laryngeal nerve; enters cardia at level of 14th rib
2. Proximal 2/3 = striated muscle, distal 1/3 = smooth muscle
3. Only abdominal portion has serosal covering
4. Moderate dilations are normal just distal to the cranial sphincter, in the distal cervical region, and in the thorax
Esophagotomy
Esophagotomy is used to remove foreign objects (particularly stomach tubes) and occasionally for choke. A longitudinal incision is made over the obstruction or in adjacent healthy esophagus. Primary closure is performed if healthy tissue; otherwise it is left to heal by second intention.
Esophagostomy
The esophagus is opened in the midcervical region. Esophagostomy is used for extraoral alimentation as an alternative to indwelling nasogastric tube. The tube is removed after 7-10 days -a stoma will be present that can be used for feeding. The stoma is allowed to heal by second intention when no longer needed.
Esophageal surgery complications
- Dehydration + hyponatremia, hypochloremia, and transient metabolic acidosis
- Dehiscence – difficult area for healing; can dehisce despite meticulous technique
- Laryngeal hemiplegia due to trauma to the recurrent laryngeal nerve at surgery or with inflammation
- Aspiration pneumonia
- Pleuritis
- Horner’s syndrome due to trauma to the sympathetic trunk
- Laminitis from high concentrate slurry diet
- Chronic choke
- Esophageal stricture
sutured edges come apart; lack of healing of incision